Objective To evaluate the efficacy of the hormonal and nonhormonal approaches to symptoms of sexual dysfunction and vaginal atrophy in postmenopausal women.Data Sources We conducted a search on the PubMed, Embase, Scopus, Web of Science, SciELO, the Cochrane Central Register of Controlled Trials (CENTRAL), and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases, as well as on clinical trial databases. We analyzed studies published between 1996 and May 30, 2020. No language restrictions were applied.Selection of Studies We selected randomized clinical trials that evaluated the treatment of sexual dysfunction in postmenopausal women.Data Collection Three authors  reviewed each article based on its title and abstract. Relevant data were subsequently taken from the full-text article. Any discrepancies during the review were resolved by consensus between all the listed authors.Data Synthesis A total of 55 studies were included in the systematic review. The approaches tested to treat sexual dysfunction were as follows: lubricants and moisturizers (18 studies); phytoestrogens (14 studies); dehydroepiandrosterone ; ospemifene (5 studies); vaginal testosterone (4 studies); pelvic ﬂoor muscle exercises (2 studies); oxytocin (2 studies); vaginal CO2laser (2 studies); lidocaine (1 study); and vitamin E vaginal suppository (1 study).Conclusion We identified literature that lacks coherence in terms of the proposed treatments and selected outcome measures. Despite the great diversity in treatment modalities and outcome measures, the present systematic review can shed light on potential targets for the treatment, which is deemed necessary for sexual dysfunction, assuming that most randomized trials were evaluated with a low risk of bias according to the Cochrane Collaboration risk of bias tool. The present review is registered with the International Prospective Register of Systematic Reviews . According to the North American Menopause Society (NAMS), natural menopause is defined as the final menstrual period, diagnosed after 12 consecutive months of spontaneous amenorrhea without an apparent pathological cause. The most common symptoms associated with menopause are hot flushes, night sweats, sleep disturbance, vaginal atrophy, and dyspareunia.StudiesAccording to the American Psychiatric Association (APA),The measurement of sexual function in women has never been an easy task. Furthermore, the literatureBecause of the complexity of FSD, it is often difficult to define the factors primarily responsible for the disorder and to establish meaningful steps in the treatment. The treatments usually aim to deal with individual symptoms, but no single treatment modality addresses the entire spectrum of the disorder. Therefore, multimodal therapy is required. The great variety of distinct classes of medication described in the literatureSeveral options are available to treat this condition, and hormonal therapies  and nonhormonal therapies  are the most commonly used. It is recognized that vaginal estrogen may improve the symptoms; conversely, non-HTs can be useful in specific cases in which HTs are harmful or not recommended (such as breast cancer).The real effect of the treatments on sexual function in menopausal women is particularly difficult to understand based on the literature published so far, partly because of different drugs, routes, and dosages, as well as the diversity of tools used to assess sexual function and the studied population in each trial. Similarly, it is essential to have guidance on effective alternative treatments for women who cannot use HTs. Thus, there is a real need for a systematic review of the best available evidence to facilitate evidence-based decisions. Thus, the present systematic review aimed to evaluate the efficacy of hormonal and nonhormonal approaches for symptoms of sexual dysfunction and vaginal atrophy in postmenopausal women.www.trialscentral.org;www.controlled-trials.com). We included studies published from 1996 until May 30, 2020 without language restrictions. Grey literature was not searched. Combinations of the following keywords were used to identify the studies:menopause;postmenopause;dyspareunia;orgasm;therapeutics;dehydroepiandrosterone;testosterone;oxytocin;phytoestrogens;lidocaine;hyaluronic acid;lubricants; andlaser. The PubMed search strategy is shown inThe present systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statementThree authors  reviewed each article based on its title and abstract. The relevant data were subsequently taken from the full-text article. We evaluated the full text based on the following inclusion criteria: 1) studies with postmenopausal women; 2) randomized clinical trials evaluating the efficacy of hormonal or nonhormonal approaches to sexual dysfunction; 3) intervention groups undergoing treatment for sexual dysfunction; 4) any HT  or non-HT being compared to a placebo or no intervention or vaginal estrogen ;The full texts of potentially-eligible studies were extracted and examined for the following data: year the study was conducted; number of subjects; location of subject recruitment; mean age of the subjects; randomization and blinding processes; inclusion and exclusion criteria; description of the therapies used, and definition of the outcomes measured; length of follow-up; and side effects. Any discrepancies during the review were resolved by consensus between all the listed authors.The primary outcomes were vaginal dryness, arousal, desire, orgasm, lubrication, satisfaction, pain, and dyspareunia. The secondary outcomes included side effects, treatment duration, and adhesion. The outcomes of the randomized controlled trials included had to be measured using gynecological and visual examinations, pH, cell maturation index, and validated scales. For the secondary outcomes, the side effects were evaluated according to the records of their onset and throughout treatment by self-assessment questionnaires.To assess the risk of bias, the Cochrane Collaboration risk of bias tool was applied to evaluate the following criteria: adequate sequence generation; allocation concealment; blinding; incomplete outcome data; selective reporting; and other risks of bias.As for the quantitative studies, we could not perform a formal statistical analysis because of the heterogeneity of the measurements. However, the findings relevant to the aims of the present review were extracted.After searching the databases, 25,631 articles were identified . After 2laser (2 studies);A total of 55 studies were deemed eligible for inclusion . The apOverall, 18 studies evaluated the parameters of dyspareunia and vaginal dryness, 2 evaluated symptoms of VVA, and the other studies used validated questionnaires for the evaluation of sexual dysfunction.Regarding side effects, the results for lubricants and moisturizers indicated that all adverse events (AEs) were considered mild in severity and self-limited.soyflour andfennelcream, no adverse effects were reported in any of the included studies.Cimicifuga foetidaextract was found to be effective and safe during three months of treatment.ginseng, 12 events were reported during a clinical trial;Tribulus terrestris, the most frequent adverse effects were diarrhea, nervousness, dizziness, and nausea.Fordischarge at the application site,urinary tract infection, andheadache. No adverse effects were observed regarding hepatic tests, hematocrit, or any hematological or biochemical parameters.Approximately half of the subjects treated with DHEA experienced the most frequently reported treatment-emergent AEs (TEAEs). The three most commonly reported preferred terms wereOspemifene was shown to be safe and well tolerated. Most TEAEs were classified as not related to the study drug or were unlikely to be related. The most frequent were urinary tract infection, hot flush, and nasopharyngitis. Only two patients experienced serious AEs, one of which was probably treatment-related (deep vein thrombosis).All related AE treatments with vaginal testosterone were classified grade 1 (mild) or 2 (moderate). The most frequent were vaginal discharge, facial hair growth, vaginal or vulvar itching and/or irritation, vaginal odor, and urinary tract or yeast infection.2laser,None of the study participants reported any side effects related to the use of oxytocin.The female population is aging and facing new health issues, including menopause symptoms and FSD. Despite this, the best approach to sexual dysfunction in menopausal women is still unclear.Until now, estrogens and androgens for FSD have been shown to improve not only dyspareunia and vaginal dryness but also the desire and orgasm domains. However, not all women can use them; breast cancer, endometrial cancer, and deep venous thrombosis, among other conditions, can be contraindications for HTs. Moreover, there is insufficient evidence to attest to the effectiveness of the non-HTs studied to improve orgasm, lubrication, and sexual satisfaction in menopausal women.The present review suggests that the use of lubricants and moisturizers has a lower impact than that of vaginal estrogens. The domains in which improvement was more evident were dyspareunia and vaginal dryness. The results of the present review point out the efficacy of hyaluronic acid for the symptoms of vaginal atrophy when compared with vaginal estrogen. Previous studies by Ekin et al.Although pelvic floor muscle exercises have been widely discussed, only a single clinical trial has been found. The results concerning pelvic floor muscle showed that exercises have the potential to improve sexual function and are thus suggested to accompany other healthcare treatments designed for postmenopausal women.Ospemifene is a selective estrogen receptor modulator (SERM) that has been approved for the treatment of dyspareunia associated with VVA due to menopause. According to the studiessoy flour,ginseng,isoflavones,C. foetida,Glycine max(L.),T. terrestris,fennel cream,ginkgo biloba,Pueraria mirifica.T. terrestriscould be a safe alternative for the treatment of sexual desire disorder, since its probable mechanism of action involves an increase in the serum levels of free and bioavailable testosterone.A wide variety of phytoestrogens are being used to improve sexual function in symptomatic postmenopausal women. The phytoestrogens found in the present review were as follows:Vaginal HTs, DHEA, and testosterone may have a positive impact on sexual desire and sexual function. The present review indicates that the vaginal HT with DHEA may have a positive impact on sexual desire and sexual function. This beneficial effect was apparent in all domains of sexual function, not only in those related to dyspareunia and vaginal dryness.Regarding testosterone, what is known so far is that the efficacy of the therapy may rely on synergistic effects with estrogen.Most treatments are considered safe, and no side effects were considered severe, only moderate to mild. It is important to highlight the lack of data about the side effects in some studies, which ends up generating uncertainties the true safety of treatment. According to the GRADE classification, the present study provided moderate or very low certainty of evidence that HTs or non-HTs are useful to improve sexual function in postmenopausal women. Consequently, the findings of the present study cannot be generalized until new randomized clinical trials are performed to confirm the strength of the evidence.The present systematic review identiﬁed that the literature lacks coherence in terms of the proposed treatments and selected outcome measures. There is great diversity and heterogeneity in the scales used for the assessment of sexual dysfunction, despite the fact that they have been validated, hence the need for standardization in the scores. One of the most commonly used, the Female Sexual Function Index, is problematic regarding non-sexually active women. The present review should be considered in the context of its limitations. Despite the great diversity in treatment modalities and outcome measures, the review can shed light on potential targets for treatment, which is deemed necessary for sexual dysfunction, assuming that most randomized trials were evaluated with a low risk of bias, according yours methodological characteristics.


Trace elements and minerals play a significant role in human health and diseases. In recent years, ionomics has been rapidly and widely applied to explore the distribution, regulation, and crosstalk of different elements in various physiological and pathological processes. On the basis of multi-elemental analytical techniques and bioinformatics methods, it is possible to elucidate the relationship between the metabolism and homeostasis of diverse elements and common diseases. The current review aims to provide an overview of recent advances in the application of ionomics in metabolic disease research. We mainly focuses on the studies about ionomic or multi-elemental profiling of different biological samples for several major types of metabolic diseases, such as diabetes mellitus, obesity, and metabolic syndrome, which reveal distinct and dynamic patterns of ion contents and their potential benefits in the detection and prognosis of these illnesses. Accumulation of copper, selenium, and environmental toxic metals as well as deficiency of zinc and magnesium appear to be the most significant risk factors for the majority of metabolic diseases, suggesting that imbalance of these elements may be involved in the pathogenesis of these diseases. Moreover, each type of metabolic diseases has shown a relatively unique distribution of ions in biofluids and hair/nails from patients, which might serve as potential indicators for the respective disease. Overall, ionomics not only improves our understanding of the association between elemental dyshomeostasis and the development of metabolic disease but also assists in the identification of new potential diagnostic and prognostic markers in translational medicine. Metabolic diseases are well-known as a major threat to global public health, which include diabetes mellitus (DM), obesity, metabolic syndrome (MetS), non-alcoholic fatty liver disease (NAFLD), hyperlipidemia, hyperuricemia (or gout), bone metabolic disease , and some other diseases that are caused by endocrine dysfunction  or nutrient imbalance (such as Wilson's disease) , 2. In tAmong known risk factors and possible molecular mechanisms associated with metabolic diseases, dyshomeostasis of various elements has been implicated in the onset and progression of many types of them –6. ExcepIt has been known that the cell has developed complex regulatory mechanisms  to tightly control the metabolism and homeostasis of various trace elements in order to ensure appropriate supply while preventing accumulation to toxic levels . PreviouIn the recent 20 years, with the explosive growth of multi-omics data  and a corresponding increase in data analysis methods, the complex relationship between trace elements and human health or diseases has been examined comprehensively. The concept of metallome  and its extension ionome  have also been introduced , 24. IonIn this review, we present a comprehensive survey on the complex relationship between ionomic profiles in diverse human biological samples and several major types of metabolic diseases mainly based on recent large-scale ionomic/metallomic studies, such as case-control studies, cohort- and population-based studies, and meta-analyses. Such information may provide a holistic and integrated understanding of the critical roles trace elements play in metabolic diseases.The major purpose of ionomics is to measure the ion contents in a biological system and to elucidate their correlations to phenotypes of interest. Nowadays ionomics has been widely used for studies on environmental monitoring, nutrient utilization, biofortification, food safety, and forward and reverse genetics, particularly in plant developmental and stress biology which has been extensively reviewed in the literature , 33–35. In early times, elemental profiling analysis in various samples was mainly used in geoscience, environmental science, and ecological studies. In the last decade, ionomics has grown in popularity in different areas of life science as a powerful tool for studying the metabolism and homeostasis of diverse trace elements and minerals in different organisms, including plants and humans. The major techniques for the quantification of chemical elements include inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma atomic/optical emission spectroscopy (ICP-AES/ICP-OES), X-ray fluorescence (XRF), atomic absorption spectrometry (AAS), neutron activation analysis (NAA), and several other methods , 33. CurWith the increase in volume of data generated by ionomics studies, it becomes more and more important to develop appropriate information management systems for ionomics data acquisition, storage, retrieval, and analysis. However, publicly accessible platforms and databases that allow researchers to obtain such resources are very rare so far. The iHUB system is the first integrated workflow system, which contains ionomics data of yeast and important plants such as Arabidopsis thaliana, maize, rice, and soybean, and provides open access for raw data management, data mining and analysis, and knowledge discovery . The OPTOn the other hand, with the rapid progress in the experimental and computational identification of novel trace element-related genes and their functions, relevant information should be well-maintained for further utilization. A known ionome gene (KIG) database was recently developed, which is a curated list of genes known to affect uptake, accumulation, and distribution of elements in several plant species . New sysvia multiple approaches  and advanced multivariate statistical methods , which could also be applied for other types of omics data . Moreoveproaches .Before the concept of ionomics was introduced, ICP-MS had been used to evaluate the concentrations of certain trace elements in biofluids, hair, nails, and some other human tissues for different diseases such as cancer, neurodegenerative diseases, and coronary heart disease, demonstrating that imbalance of trace elements may be one of the risk factors of many complex or common diseases –53. MostIt has been known for a long time that trace elements and minerals play a critical role in the onset and progression of metabolic diseases , 54, 55.DM comprises a group of metabolic diseases characterized by chronic hyperglycemia resulting from insufficient insulin secretion and/or insulin resistance in target tissues, which may lead to multi-organ dysfunction and failure . There ap < 0.05) between elements and increased Cu/Zn ratio were also reported, suggesting possible benefits of the use of such information in detection and prognosis evaluation of T2DM , urine, hair, and even teardrops have been examined in different cohorts of patients with T2DM, implying that changes in elemental profiles represent a potential source of biomarkers of this complex disease –70. The  of T2DM , 63. By  of T2DM , 70–72.  of T2DM . On the  of T2DM –80. For  of T2DM . Long-te of T2DM , 75. Alt of T2DM , the maj of T2DM . In addi of T2DM . Other i of T2DM , 83.Ionomics studies have also been conducted for several other types of DM –87. One Obesity is a chronic and complex disease characterized by excessive amounts of fat within adipocytes, which may result from insulin resistance, dysregulation in lipid and other metabolic balances, and inflammatory and/or hormonal processes . It may Before the use of ionomics in obesity research, many studies have shown a possible relationship between obesity and disturbance of homeostasis of certain trace elements, such as Zn or Fe deficiency and Cu overload, although the exact metabolic roles of these elements remain unclear –102. In A significant number of studies with larger cohorts have been performed recently to improve our understanding of the relationship between obesity and single or few essential/non-essential elements in various biofluids and tissues, which showed generally similar changes in the concentrations of some of them in different populations, such as increased serum and hepatic tissue Cu levels , 120, deMetS is a group of metabolic disorders, including abdominal obesity, hypertension, high blood sugar levels (insulin resistance or glucose intolerance), and dyslipidemia [high triglyceride and low high-density lipoprotein (HDL)-cholesterol levels]. It may raise the risk of CVD, T2DM, stroke, and other serious health problems . The cauIn early years, a limited number of studies have been conducted to explore the distribution and relationships of selected trace elements in different samples of patients with MetS and normal controls, which revealed that some of these elements might be related to the incidence and course of MetS –140. ForSeveral ionomic profiling studies with large cohorts of patients were carried out in the recent decade , 142–150Besides the ionome-level studies mentioned above, more case-control studies and meta-analyses recently focused on single or several trace elements and explored their differences between MetS patients and healthy controls in different biological samples , 155–164NAFLD is the most common chronic liver disease worldwide, which is characterized by excessive fat accumulation (≥5%) in hepatocytes in the absence of excessive alcohol consumption . It encoThe association between certain trace elements and NAFLD risk has been reported since 1990s, such as hepatic Fe overload and lower liver and serum Cu concentrations in different types of NAFLD patients  –177. TheIn the last few years, a large number of studies have explored the correlation between single or several elements and the development of NAFLD. First, consistent with previous findings, Fe accumulation appears to be the most significant and common marker for NAFLD, and indicators of Fe status  could be used for the prediction of disease severity and adverse outcomes (such as the risk of advanced hepatic fibrosis and HCC) in different populations –186. SecHyperlipidemia  represents the condition of abnormally elevated levels of one or more lipids and/or lipoproteins in the blood, mainly including high levels of total cholesterol (hypercholesterolemia), triglycerides (hypertriglyceridemia), and low-density lipoprotein (LDL)-cholesterol or low levels of HDL-cholesterol. It is a significant risk factor for a variety of diseases such as fatty liver, CVD, DM, neurodegenerative diseases, and acute pancreatitis . HyperurThe relationship between hyperlipidemia and trace element homeostasis has been analyzed in early times. Deficiency of several essential elements , Cu excess, and significant urinary excretion of Fe, Zn, and Cu were observed to be associated with the prevalence of hyperlipidemia –219. HowDyshomeostasis of trace elements has also been implicated in the incidence and progression of hyperuricemia for a long time. In general, circulating levels of several essential metals  and toxic metals (Pb and As) showed positive correlations with the prevalence of hyperuricemia in different populations –238. In Osteoporosis is a systemic bone metabolic disease characterized by bone mass reduction and bone microstructure destruction, which increases the risk of fracture, particularly in older postmenopausal women. The pathogenesis of osteoporosis is complex and involves the interaction of genetic, hormonal, environmental, and nutritional factors . OsteomaThe correlation between certain trace element and mineral levels within the body and osteoporosis has been examined in a large number of population-based studies, case-control cohort studies, and meta-analyses since the early 1970s. In general, reduced circulating levels and/or elevated urinary excretion of a variety of essential metals  as well as accumulation of Fe, Mn, and toxic heavy metals  are strongly related to the prevalence of osteoporosis –266. In In the past several decades, besides low serum levels of Ca and P that have been proposed as a screening test in patients who have clinical symptoms suggestive of osteomalacia , elevateComparison of the integrated ionomic profiles in different biological samples for major types of metabolic diseases has demonstrated common/specific trends in the changes of elemental contents . ConsideAmong all examined ions, Cu levels are significantly increased in almost all examined samples (except hair/nails) from patients with various metabolic diseases (except NAFLD and bone metabolic diseases), indicating that Cu accumulation is one of the common risk factors for a wide variety of metabolic diseases and might act as a general marker for diagnosis and poor prognosis of them. Elevated concentrations of Se and environmental heavy metals  and reduced levels of Zn and Mg are often observed in the blood/serum/plasma and hair/nails in patients with metabolic diseases, suggesting that alternations in the homeostasis of these elements may also serve as indicators of these diseases. In contrast, higher excretion of Zn and lower excretion of Se, Cd, and Pb in the urine were observed in several major types of metabolic diseases , which may partially contribute to the imbalance of these elements within the patients. In addition, the Cu/Zn ratio is also increased in the serum/hair from patients with T2DM and obesity, indicating its potential as a general circulating marker for these diseases.Although the elemental contents are distinct and highly dynamic in different samples from patients with same/different metabolic diseases, each sample type appears to have specific ionomic pattern, which could be further used to develop novel biomarkers or prediction models for the respective disease. Clustering analysis revealed that same sample types from patients with different metabolic diseases may have quite similar or correlated ionomic patterns , such asAlthough ionomics provides valuable insights into the mineral and trace element composition in a living organism and their relationship with different physiological and pathological conditions, there are still limitations for its potential role in diagnosis and prognosis of various diseases including metabolic diseases. One major limitation of current ionomics studies is the relatively small number and the varying characteristics  of patients and controls enrolled in different projects, which might restrict the power of ionomic evaluation when considering the high variability of trace element contents in biological samples. Another limitation is that ionomics study could not provide a definite cause and effect relationship between dyshomeostasis of trace elements and the development of metabolic diseases. Moreover, studies on the connection between alternations of elemental profiles and the levels of element-binding proteins  and the dynamic interplay between elements are still lacking for most metabolic diseases. Nevertheless, ionomic analyses of biofluids, hair, nails, and other related tissues may be useful to give a comprehensive overview of the complex interactions between trace elements and minerals and metabolic diseases and help to generate new fingerprints for diagnosis, prognosis, and even for evaluation of therapeutic efficacy in these diseases, which cannot be solved only by the assessment of single or very few element levels.Disruption of ion metabolism and homeostasis plays a significant role in various diseases including cancer, metabolic diseases, neurological diseases, CVD, and many more. In the recent decade, ionomics has become a powerful tool for systematically investigating the composition and distribution of trace elements and minerals in different biological systems. However, our understanding of the relationship between ionome and the pathogenesis of metabolic diseases is limited so far.This review focuses on several major types of metabolic diseases and introduces recent progress in the application of ionomics in the study of these diseases, which may raise the possibility of using such information for early detection and prognosis of patients with metabolic disease. Increased Cu concentrations in the majority of biological samples appear to be the most significant marker for various metabolic diseases. Elevated circulating levels of Se and environmental toxic metals and reduced Zn levels have also been demonstrated to be the common risk factors for the majority of metabolic diseases. Other elemental and inter-elemental biomarkers may also reflect the imbalance of ion contents that occurs in different samples of same/different types of metabolic diseases. In spite that the use of ionomics in the field of human disease remains at the initial stage, it may help to depict the crosstalk among different ions in disease pathogenesis and provide a potential source of diagnostic, prognostic, and predictive biomarkers, particularly in the context of metabolic disease. Future research with larger and more representative samples and/or more complex elemental composition  is encouraged to improve our current understanding of the association between the ionomic network and the onset and progression of different types/subtypes of metabolic diseases.YZ and HY conceived and wrote the manuscript. BH, JJ, and YX reviewed and edited the manuscript. All authors contributed to the article and approved the submitted version.


A significant percentage of the mitochondrial mass is replaced on a daily basis via mechanisms of mitochondrial quality control. Through mitophagy  cells keep a healthy pool of mitochondria, and prevent oxidative stress and inflammation. Furthermore, mitophagy helps adapting to the metabolic demand of the cells, which changes on a daily basis.in vitro in different cell types. However, recent advances in the field allowed discovering that mitophagy seems to be only slightly affected in PINK1 KO mice and flies, putting into question the physiological relevance of this pathway in vivo in the whole organism. Indeed, several cell-specific PINK1/Parkin-independent mitophagy pathways have been recently discovered, which appear to be activated under physiological conditions such as those that promote mitochondrial proteome remodeling during differentiation or in response to specific physiological stimuli.Core components of the mitophagy process are PINK1 and Parkin, which mutations are linked to Parkinson’s Disease. The crucial role of PINK1/Parkin pathway during stress-induced mitophagy has been extensively studied In this Mini Review we want to summarize the recent advances in the field, and add another level of complexity by focusing attention on a potentially important aspect of mitophagy regulation: the implication of the circadian clock. Recent works showed that the circadian clock controls many aspects of mitochondrial physiology, including mitochondrial morphology and dynamic, respiratory activity, and ATP synthesis. Furthermore, one of the essential functions of sleep, which is controlled by the clock, is the clearance of toxic metabolic compounds from the brain, including ROS, via mechanisms of proteostasis. Very little is known about a potential role of the clock in the quality control mechanisms that maintain the mitochondrial repertoire healthy during sleep/wake cycles. More importantly, it remains completely unexplored whether (dys)function of mitochondrial proteostasis feedbacks to the circadian clockwork. In addition to the central pacemaker, circadian clocks are also present in many other tissues: these peripheral or “slave” oscillators are coordinated by the SCN through neurotransmitters and neuromodulators, but can also entrain to signals other than light , in which positive elements promote the rhythmic transcription of the negative elements that, in turn, inhibit the activity of the positive elements . The mamCircadian rhythmicity has a very relevant role in everyday life, it is therefore not surprising that circadian disruptions are closely related to the development of diseases like cancer, cardiovascular disease, obesity, diabetes and sleep disorder reviewed in Xie et al. . Of noteIn the investigation of the molecular mechanism linking circadian rhythms to neurodegeneration in PD, mitochondria appear as an interesting suspect. These double membrane organelles are essential for cell life, representing the major source of cellular ATP and performing many functions, not least overseeing the metabolic demand of the cell. Mitochondria are highly dynamic, and can adapt their activity to meet the different bioenergetic demands of the cell through cycles of mitochondrial fission and fusion. Nearly every aspect of mitochondrial function depends on mitochondrial dynamics, including mechanisms of mitochondrial quality control that have evolved to maintain the mitochondrial repertoire healthy, and prevent oxidative stress and inflammation. Two proteins, PINK1 and Parkin, which mutations are linked to juvenile forms of PD, belong to the core machinery that surveys mitochondrial proteostasis, by orchestrating the selective removal of damaged mitochondria via autophagy. In the process of mitochondrial autophagy , the mitochondrial network undergoes important morphological changes that depend on the coordinated activity of fission and fusion events. Importantly, while many studies support the hypothesis of a clock-dependent regulation of mitochondrial dynamic, very little attention has been paid to explore whether mitochondrial proteostasis, mitophagy in particular, undergoes circadian oscillation, how this is generated, and whether this is a cell-autonomous or non-autonomous mechanism. Hints towards the hypothesis of a clock-dependent regulation of general proteostasis come from the observation that inessential byproducts and proteotoxic compounds, such as β-amyloids, accumulate during the active phase, and are degraded by the proteasome while sleeping . MoreoveIn the following chapters we will summarize recent advances in the field of mitophagy, and focus our attention on a potentially important aspect of mitochondrial proteostasis: the implication of the circadian clock and sleep homeostasis.Quality control mechanisms have evolved to maintain healthy cells, and they are crucial for cellular function. They mainly relay on the proteolitic activity of the ubiquitin proteasome and lysosome-autophagy system, two fundamental degradative systems that cooperate to oversee protein and organelle quality control. Among these mechanisms of quality control, of particular relevance are those that regulate the quality of the mitochondrial repertoire. Mitochondria represent the major site of cellular ATP biosynthesis, and perform essential metabolic functions. These double membrane organelles can however become professional killers, and major sources of oxidative stress. Thus, impaired mechanisms of mitochondrial quality control can pose a threat for cell function and survival, especially when these organelles are not functioning properly.in vivo studies in flies fully support this hypothesis , protein kinase PINK1 is stabilized on the surface of a subset of mitochondria  , it phospothesis . There apothesis , indicatpothesis , and morillation . These sde novo but rather recruits and imports new proteins to the organelle with subsequent division by fission to generate uneven daughter units. In this scenario, one unit exhibits increased MMP and high probability to fuse, while the other has decreased MMP, loses its pro-fusion capacity, and is eliminated by autophagy , even iin flies . This un fashion . Another fashion  or in re fashion . Alterna fashion , neurona fashion , maturat fashion , and whi fashion . In supp fashion .Another intriguing hypothesis is that the occurrence of the PINK1/Parkin mitophagy pathway changes on a daily basis depending on the metabolic demand of the cell, which also changes during the day, and most predictably between the active and inactive phase of the organism. In this respect, if we hypothesize that a specific mitophagy pathway occurs during the inactive phase , loss of it might undergo unnoticed if the readout in real time is performed during the active phase. This could partially explain why the fluorescent mitophagy reporters did not record a readable difference in basal mitophagy between WT and PINK1 KO flies, while the proteomic approach proved to be more effective.in vivo in mice liver showed that mitochondrial dynamic is controlled by circadian rhythmicity in a fashion that is independent of nutrient intake. In particular, mice with liver specific ablation of clock gene Bmal1 exhibit disrupted rhythmicity in the gene and protein level of pro-fission Fis1 and in the mitophagic genes and proteins Pink1 and Bnip3, accompanied with enlarged and swollen mitochondria, dysfunctional oxidative metabolism and ATP synthesis. Importantly, this effect of Bmal1 ablation is independent of nutrient availability. Thus, in BMAL1 deficient cells, protein levels of Fis1, PINK1 and BNIP3 fail to accumulate in anticipation of the upcoming feeding phase, leading to disrupted mitochondrial fission and quality control that are presumably required for the metabolic remodeling that anticipates the feeding phase. Notably, promotion of mitochondrial fission rescues the aberrant metabolic and circadian phenotype associated to BNIP3 KO animals, supporting the hypothesis that mitochondrial dynamic and quality control can signal back to re-establish a functional clock  in the retina, whose connections deliver photic information to the SCN to synchronize the clock. These evidences can partially explain why older adults develop circadian dysfunction and sleep disturbances. Nevertheless, patients with neurodegenerative diseases experience more pronounced circadian rhythm dysfunction compared to age-matched counterpart, and disturbance in the sleep-wake cycle is perhaps the most common non-motor symptom found in up to 80% PD patients. Interestingly, in the retina of PD patients the number of ipRGCs is reduced compared to age-matched counterpart , and theSeveral correlative studies support the hypothesis of a causal link between neurodegeneration in PD and aberrant circadian rhythms, with both neurotoxin and genetic animal models of PD reproducing the defective circadian pattern observed in patients . HoweverIn the investigation of the potential molecular mechanism linking PD to disruption of circadian oscillation, loss of mitochondrial proteostasis is a potential suspect. The retina is a region of high-metabolic demand of the CNS, and mitochondrial dysfunction has been linked to retinal pathology , thus abin vivo (Mitophagy and autophagy levels have been recently measured in different cells of the mammalian eye, using the mito-QC mitophagy reporter  and a GFin vivo . The appPer2 in a time-of-day dependent manner (It is currently unclear whether enhancement of autophagy/mitophagy may serve to protect neurons during neurological disorders or whether it can boost neuronal damage. For instance, sleep deprivation, which is used to study the homeostatic component of sleep, has been recently linked to excessive pathological enhancement of autophagy and mitophagy . It is pt manner , and thet manner , supportt manner . Sleep it manner ; both coThe circadian clock controls mitochondrial dynamic to allow mitochondrial adaptation to predictable metabolic daily changes. Mechanistically, the relationship between the clock and mitochondria dynamic has not been fully depicted, but cell-autonomous oscillation of mitochondrial fission that depend on the expression of clock core components, seems to be of crucial importance .Post-mitotic cells like neurons are thought to be particularly sensitive to disruptions in mechanisms of mitochondrial dynamics. In these cells, mitochondrial fission exerts pro-survival effects by many means , not leaIt is currently unclear whether sleep and circadian dysfunction are causes or consequences of neurodegenerating DA neurons, and how mitochondrial physiology fits into this picture. Nevertheless, elucidating the mechanism underlying the putative relationship between mitochondrial homeostasis, the circadian clock, and neurodegeneration will help establishing whether a cause-effect relationship exists between the circadian and mitochondrial defective phenotypes observed in patients with neurodegenerative diseases, and if treating circadian disturbance in patients with neurodegenerative diseases may have therapeutic implication.


Osteoarthritis (OA) is a common chronic degenerative disease of articular cartilage in middle-aged and older individuals, which can result in the joint pain and dysfunction, and even cause the joint deformity or disability. With the enhancing process of global aging, OA has gradually become a major public health problem worldwide. Explaining pathogenesis of OA is critical for the development of new preventive and therapeutic interventions. In recent years, gut microbiota (GM) has been generally regarded as a “multifunctional organ,” which is closely relevant with a variety of immune, metabolic and inflammatory functions. Meanwhile, more and more human and animal researches have indicated the existence of gut-bone axis and suggested that GM and its metabolites are closely involved in the pathogenic process of OA, which might become a potential and promising intervention target. Based on the close coordination of gut-bone axis, this review aims to summarize and discuss the mechanisms of GM and its metabolites influencing OA from the aspects of the intestinal mucosal barrier modulation, intestinal metabolites modulation, immune modulation and strategies for the prevention or treatment of OA based on perspectives of GM and its metabolites, thus providing a profound knowledge and recognition of it. Osteoarthritis (OA) is a common chronic degenerative disease of articular cartilage in middle-aged and older individuals, mainly manifested as the progressive destruction of articular cartilage, subchondral sclerosis and hyperplasia, periarticular osteophyte formation and synovial lesions, which can result in the joint pain and dysfunction, and even cause the joint deformity or disability –3. With As a kind of complex chronic degenerative disease, the etiology and pathogenesis of OA are still unclear, and the corresponding treatment or intervention approaches are relatively limited. The current strategies of OA mainly include drug treatment, physical intervention and surgeries. Hence, based on the original cognition of OA , a deeper explanation of the underlying mechanisms of OA is crucial for the development of prevention and treatment strategies. Furthermore, more and more evidence has suggested that gut microbiota (GM) and its metabolites play a vital role in the occurrence and progression of OA . As the In recent years, more and more researches have suggested that the dysregulation of GM and its metabolites is not only involved in the pathogenic process of the intestinal diseases , but also the imbalance of intestinal homeostasis may induce several extraintestinal immune and metabolic diseases  –21. RegaEscherichia coli and Staphylococcus  into the blood, and the inflammatory response induced by LPS may be involved in the pathogenesis of OA. Li et al. , is prone to be reduced by HFD, and the intestinal permeability also alters, resulting in a large amount of LPS entering systemic circulation  . When GMculation . Meanwhiculation . Based oculation .In addition to this, 5-HT could disrupt the dynamic balance between bone formation and bone resorption, thereby influencing the maintenance of bone mass. GM plays an important role in the production of 5-HT, and previous studies have also indicated that GM can stimulate the chromaffin cells to produce 5-HT, and microorganisms can also regulate gastrointestinal motility via the neural secretion mechanism activated by toll like receptors (TLRs) , 80. BesIn addition, GM could also modulate and inhibit the dietary inflammatory response produced in the daily intake of foods, which also play a critical role as antigens in the immune system . As a kiThere is a close relationship between GM and intestinal mucosal immune system, and the degree of change in intestinal microecology determines the stability of intestinal mucosal immune system and systemic immune system. The direct contact between GM, its metabolites and immune cells stimulates the immune response of intestinal mucosal barrier –91. The Prevotella copri can promote the differentiation of regulatory T (Tregs) cells and Th17 cells in the intestine, and Tregs cells induce the production of retinoic acid-related orphan receptor γt (RORγt) to further promote the differentiation of Th17 cells  colonized and adhered to the intestinal epithelial cells, the intestinal Th17 cells were then induced and aggregated. In a recent study involving the oral-GM axis, du Teil Espina et al.  can promote the production of anti-citrullinated protein antibodies  in the type II diabetic and obese mice is significantly reduced. However, when the mice are fed with polyphenol-rich cranberry extract, the number of A. muciniphila increases significantly, and the glucose tolerance and insulin sensitivity are improved accordingly  rats. Henrotin et al.  and glycosaminoglycans were significantly enhanced. As a consequence, the application of tyndallized C. butyricum also effectively protected the cartilage and synovium of knee joint, and reduce the formation of fibrous tissue. In addition to this, by comparing applications of probiotic containing capsules, including the Lactobacillus rhamnosus, Saccharomyces cerevisiae (boulardii), and Bifidobacterium animalis ssp. lactis, and placebo capsules without probiotics to the participants with OA, Taye et al. (TCI633 (Streptococcus thermophilus) is able to produce hyaluronate in gastrointestinal tract. Lyu et al. , which is related to the obesity-related GM dysregulation, and could restore a healthy microbial community via the use of indigestible prebiotic fiber Fructooligosaccharides. Fructooligosaccharides can induce the alterations in the abundance of key microorganisms in obese individuals, decrease the response characteristics of colon macrophages, reduce the systemic and joint inflammation, protect the articular cartilage, and further alleviate the progression of OA  often refers to the transplantation of bacteria in the feces of donor to the recipient by intragastric or oral administration, thereby altering the composition, structure and abundance of GM in the recipients , 149. Dued by OA , 153. Hoed by OA . Therefoed by OA  suggesteed by OA  reporteded by OA , 158.To sum up, with the in-depth researches of the pathogenesis of OA, more and more evidence indicates that there is a close relationship between OA and GM. Although the specific mechanisms of the relationship between intestinal microecology and OA is still unclear and under intensive exploration, it is foreseeable that the characteristics of GM and its metabolites can be applied to diagnose and evaluate the OA or other bone-related diseases in the future. The functional relationship and mechanisms between GM and its metabolites and OA are summarized in LL, FT, and RX developed the idea for this manuscript. LL, FT, and WX developed the search strategy and performed the review and data extraction. LL and FT wrote the manuscript. All authors edited and agreed the final version.


Along with an aging population, exploring the impact of oral health on holistic health and determining exact outcomes in elderly individuals are important in both scientific research and clinical practice. Significant increase in the number of systematic reviews shows that oral health can directly or indirectly affect the overall health of elderly people physically, mentally and socially. To systematically collate, appraise, and synthesize the current evidence, we carried out an umbrella review of the impacts of oral health on holistic health in elderly individuals.A systematic reviews and meta-analyses search was performed in the major databases PubMed, MEDLINE, Web of Science and the Cochrane Library from inception to February 1, 2022, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The JBI (Joanna Briggs Institute) Critical Appraisal Checklist for Systematic Reviews and Research Syntheses was referred to assess methodological quality, and the GRADE  was used to assess the quality of evidence for each outcome included in the umbrella review.Out of 1,067 records, a total of 35 systematic reviews were included. Respiratory diseases, malnutrition, age-related oral changes, frailty, cognitive impairment, depression and poor quality of life were identified as seven key outcomes that affect the physical, mental and social health of elderly individuals. Meanwhile, three intervention measures of oral health were summarized as (i) more rigorous and universal scales, (ii) dental cleaning and denture installation, and (iii) improving self-awareness regarding oral care.Evidence showed that oral health can significantly affect holistic health, and the diverse oral diseases directly lead to multiple health outcomes in elderly individuals. Clear high-quality evidence revealed that oral health is strongly associated with seven health outcomes covering physical, mental, and social levels, which directly corresponds to holistic health, and impacts the quality of life of elderly individuals. Such the results remind the importance of oral care in public health, and further studies need to be conducted to verity more specific association between oral health and other chronic diseases.https://www.crd.york.ac.uk/PROSPERO/#recordDetails, identifier: CRD42022315315. With the rapid aging of the population worldwide, the holistic health of elderly individuals has become a crucial issue in both developing and developed countries , 2. In gFor instance, evidence has shown that 15% of cases of community-acquired pneumonia or other respiratory diseases, which are considered some of the most common chronic diseases among elderly individuals, are significantly associated with oral bacteria –18. SimuAlthough there is an increasing amount of research and systematic reviews on the impacts of oral health on different health outcomes, and published articles on corresponding topics have covered a variety of general health outcomes among elderly individuals, such studies have mainly focused on the association between oral health and some specific diseases; a body of work describing the current landscape of intervention and nursing measures that links oral health and the diverse outcomes covering physical, mental, and social health is still missing , 29. AccThe aim of this umbrella review, therefore, is to provide an overall examination and synthesis of the available qualitative and quantitative evidence on the oral health of elderly individuals from a higher-level perspective and explain the impact of oral health on multiple outcomes of holistic health among elderly individuals. On this basis, the objectives of the review are to assess, identify, analyse, and synthesize the evidence on (1) an exact correlation between oral health and multiple outcomes of holistic health in older people and (2) solutions and suggestions, including effective interventions in clinical practice for nursing care.The protocol of this study was registered in PROSPERO registry (CRD42022315315), and the review is reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA).Studies were selected based on the following eligibility criteria: (a) included a systematic review with/without meta-analyses on oral health among older people; (b) investigated the association of different multiple outcomes of holistic health among older people; and (c) included older people as the study population, which exactly corresponds to populations, interventions, comparators, outcomes and study designs (PICOS) as presented in *), using truncated terminology for all areas  AND  worked together to remove duplicates with EndNote reference management software, reviewed titles and abstracts for relevance, and finally selected the papers, which required the agreement of both reviewers. Disagreements were resolved through consensus or discussion with the third researcher (XH).Review articles included in the final analysis were critically evaluated using the “JBI Critical Appraisal Checklist for Systematic Reviews and Research Syntheses” (JBI CAC for SRRS) by two reviewers , and no Box 1CA, critical appraisal; SR, systematic reviews.The following data were extracted from each manuscript: (1) the name of the first author and publication year; (2) the study design, number of primary studies included in the meta-analysis, the study characteristics and the total number of participants; (3) the respective outcome according to the eligibility criteria; and (4) risk estimates and corresponding confidence intervals and the respective significance level. If relevant data were not available in the respective papers, we sent email inquiries to the corresponding authors. If the author did not reply or could not provide the missing data, we marked the missing information as “No”. Reviews and primary studies were classified as quantitative, qualitative or mixed methods studies. The primary studies in each review were tabulated to assess the overlap between reviews. Effectiveness was investigated by categorizing the different outcomes reported and tabulating the data, including an indication of whether the effects of the intervention were positive, negative or not statistically significant.A total of 1,066 records identified through database searching and 1 additional record identified through other sources were imported into the reference management programme EndNote X9.3.1. After examining the records in this programme, 400 duplicates were removed, and 667 records remained. Next, two authors independently screened the titles and abstracts of the remaining records, and 579 papers were excluded because they did not meet the inclusion criteria. Furthermore, based on the inclusion and exclusion criteria, 53 of the 88 articles were excluded after full-text review because these studies did not focus on elderly individuals, did not mention outcomes of holistic health, or did not include systematic reviews with/without meta-analyses. Finally, 35 review papers met the inclusion criteria and were included in the analysis and synthesis of this study. Six of the included papers were from the Netherlands, five were from the United States, five were from Brazil, four were from China, three were from Canada, two were from Australia, Iran and Sweden, and one was from the United Kingdom, Italy, Japan, Spain, Denmark and Belgium, respectively. The average number of authors was 5.3 ± 1.9. The publishing year of the papers ranged from 2003 to 2021. The average number of databases referred was 4.5 ± 1.6.The most common groups of participants investigated were elderly individuals living in hospitals or nursing homes. Meanwhile, community-dwelling or institutionalized/non-institutionalized older adults were also the main participant groups investigated in the primary studies. In addition, three studies considered all elderly individuals in general. Among the included reviews, total participants ranged from 618 to 121,547, while 13 of the included papers did not report the total number but presented the ranges of the ages of the elderly participants instead.Most of the included systematic reviews consisted of cross-sectional and longitudinal studies, and 12 reviews consisted of randomized controlled trials (RCTs). The summarized findings of the included reviews came from between 4 and 68 primary studies. Eleven reviews also conducted meta-analyses with/without RCT results that were relevant to the present umbrella review.The corresponding detailed critical assessment and risk of bias of the reviews are shown in The included papers showed a varied range of the impacts of oral health on holistic health among older people. According to the definition of holistic health, three secondary level subthemes can be conceptualized to meaningfully generalize the comprehensive outcomes.N = 23); (ii) mental outcomes (N = 6); and (iii) social outcomes (N = 6), as shown in In terms of the research topics, the subthemes based on the main theme can be identified as (i) physical outcomes  , 30 focuCandida albicans, Staphylococcus aureus, methicillin-resistant S. aureus, Pseudomonas aeruginosa, and even Escherichia, which are strongly related to mortality due to aspiration pneumonia, are much higher among older people with poor oral health  of moderate to high quality showed that regular oral care intervention and cleaning are significant factors for preventing aspiration pneumonia in older people , 51–54. Poor oral health adds to the burden of the change in the microenvironment for older people , which dFive reviews of low to high quality showed that the condition of the dentition is strongly associated with the prevalence of malnutrition in elderly individuals , 35–38, The evidence for frailty in elderly individuals is complex. Two systematic reviews of moderate quality analyzed the factors including the number of teeth, chewing ability, oral function and the accumulation of oral health problems and showed that the prevalence of frailty, which is expected to increase rapidly in the aging population, is significantly related to oral health , 58, whiSix systematic reviews provided data on mental outcomes –64, of wOne qualitative systematic review of low quality provided evidence of an association between learning and memory and complex attention and executive function and oral health in elderly individuals, of which most of the primary studies independently identified one or more significant unadjusted associations or adjusted covariates correlated with oral health . CorrespOne systematic review with a meta-analysis of high quality studied the correlation between oral health and depression, which is the main cognitive disability in elderly individuals worldwide . The revSix systematic reviews provided data on social outcomes –49, of wFour systematic reviews of moderate to high quality showed that a higher number of teeth, occluding pairs, implant-retained overdentures, and shortened dental arches were positively associated with OHQoL , 48, 49,N = 35), the majority focused on multiple physical outcomes (N = 23); six papers mainly discussed mental outcomes, and 6 papers explored social outcomes. Correspondingly, clear evidence is available to support diverse outcomes covering physical, mental and social health in elderly individuals and included respiratory diseases, malnutrition, age-related oral changes, frailty, cognitive impairment, depression and poor quality of life. It is worth noting that although there were many commonalities among the reviews included, the perspectives of the papers varied, and none of the current articles provided a systematic summary of the diverse results, which is crucial for providing better health care for elderly individuals as well as reducing the cost of medical resources  More rigorous and universal scales are needed. Although multiple outcomes of holistic health have been presented in a range of reviews and primary studies of high quality, it remains difficult to explain the relationship precisely. Moreover, popular scales are not always appropriate and may not fully represent actual oral health problems .(ii) Providing oral hygiene and professional oral health care are important factors. Although evidence has demonstrated that routine oral care can achieve the same positive results , 53, pro(iii) Improving self-awareness regarding oral care for elderly individuals is important. Oral problems are considered a cumulative process along with aging , and theIn the process of screening the literature, we noticed some interesting primary studies verifying the relationship between oral health and other chronic diseases, such as diabetes , hyperteThere has been a rapid increase in research and corresponding systematic reviews on the impact of oral health on diverse chronic or non-chronic diseases in elderly individuals, which indicates the promotion of health awareness among elderly people in society. Accordingly, an umbrella review that qualitatively and quantitatively synthesizes studies by mixed methods provides an effective platform to efficiently extract relevant information for clinical practice and future research. Because the literature search was also systematic, according to the PRISMA guidelines, it gives a more comprehensive overview and a higher-level perspective than a narrative review with a narrow topic. Meanwhile, a convincing result of the umbrella review depends on the quality of the included systematic reviews with or without meta-analyses. Eleven of the 35 included reviews were of high quality.In terms of the limitations, a more complete map of the final result in this research requires the inclusion of more studies written in languages other than English. Regarding the results of this study, although almost all of the included studies were associated with oral health, only one systematic review with 15 studies focused on depression and mental outcomes, which weakens the integrity of the conclusions. More importantly, it is worth noting that holistic health is a relatively broad concept, which indicates a wider result beyond the 7 exact outcomes in the present study. As a result, we are aware that the whole picture of the relationship between oral health and holistic health still has not been displayed through our analysis of the included papers, and that other symptoms or diseases remain to be further researched.This umbrella review provided a macro perspective to determine the multiple outcomes of holistic health associated with oral health and summarized intervention measures to improve public oral hygiene. On the basis of the consistent findings, clear evidence is available to show the multidimensional results of holistic health. Evidence indicates that oral health can be mainly divided into two issues: (i) poor oral hygiene, where the multiple pathogenic microorganisms colonizing the oral microbiome are significantly associated with respiratory disease, dental caries and periodontitis, and (ii) tooth loss and chewing problems, with which elderly individuals have a higher risk of malnutrition and frailty. The combination of the two issues can also result in poor mental health, such as cognitive impairment and depression, in older people. Correspondingly, to acquire a higher quality of life, elderly people are encouraged to clean their teeth regularly, to have dentures fitted and to receive timely oral care.Among the included reviews, the majority provided a precise point of view to illustrate the results, while a few papers, especially those regarding mental and social outcomes, were more conservative in their discussions and argued that more research is needed, although evidence has shown significant correlations. In addition, it is necessary to emphasize that due to the lack of relevant systematic reviews, some other popular chronic oral-related diseases were not included in the present umbrella review. Although there are still some limitations and other different oral-related diseases remain to be studied, this umbrella review is expected to provide a global and effective reference for clinical practice in public health.The original contributions presented in the study are included in the article/FL and XH led the current study. FL and SS initiated the study design and drafted the manuscript. FL, SS, and XH searched databases and screened the articles and extracted the data. XY and SH conducted the quality of the studies. XH, JH, and GW reviewed and revised the manuscript. All authors read and approved the final manuscript.This study was supported by Science & Technology Department of Sichuan Province (No. 2020JDKP0016).The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Micro-RNAs (miRNAs) are short non-coding single-stranded RNAs that modulate the expression of various target genes after transcription. The expression and distribution of kinds of miRNAs have been characterized in human placenta during different gestational stages. The identified miRNAs are recognized as key mediators in the regulation of placental development and in the maintenance of human pregnancy. Aberrant expression of miRNAs is associated with compromised pregnancies in humans, and dysregulation of those miRNAs contributes to the occurrence and development of related diseases during pregnancy, such as pre-eclampsia (PE), fetal growth restriction (FGR), gestational diabetes mellitus (GDM), recurrent miscarriage, preterm birth (PTB) and small-for-gestational-age (SGA). Thus, having a better understanding of the expression and functions of miRNAs in human placenta during pregnancy and thereby developing novel drugs targeting the miRNAs could be a potentially promising method in the prevention and treatment of relevant diseases in future. Here, we summarize the current knowledge of the expression pattern and function regulation of miRNAs in human placental development and related diseases. Caenorhabditis elegans [Small non-coding RNAs (ncRNAs) are a group of short non-coding RNAs that play vital roles in many biological processes and diseases . Among t elegans . Later i elegans . Same as elegans . Conside elegans ,6,7, sucThe placenta is a temporary but the largest organ in the fetus during pregnancy , while iRecently, accumulating evidence has indicated that human placental development is precisely controlled by multiple miRNAs. In both in vitro and in vivo studies using cell models and placental tissues, expression of various miRNAs is detected, whose dysregulation gives rise to the aberrant functions of placenta and is strongly associated with pregnancy-related diseases ,26,27. TSince their discovery in the early 1990s, large numbers of miRNAs have been characterized not only in plants but also in animals . MiRNAs Alterations in RNA sequence or structure will impact the maturation and turnover of miRNAs . The matThe development of human placenta is initiated by the implantation of the blastocyst , and theHuman placental villi are observed to be surrounded by a layer of mono-nucleated villous cytotrophoblasts (VCTs), which gradually undergoes fusion to form a syncytiotrophoblast (SCT) layer that is multi-nucleated. This multi-nucleated syncytium layer directly interacts with maternal blood and is fundamentally involved in the secretion and transportation of gas, nutrients and waste products across the materno–fetal interface ,58. The Owing to the detection methods such as Northern blot assays , quantitMicroRNA microarray is a newly developed method with its capacity of powerful high-throughput in profiling the expression of miRNAs (particularly the large miRNAs) at the same time ; howeverIt is now believed that many kinds of miRNAs can be efficiently produced by human placenta, particularly by placental trophoblasts . So far,Epigenetic regulation, involving heritable changes in expression of genes or phenotype of cells without alterations of the underlying DNA sequence, has been shown to participate in controlling the expression of human placental miRNAs. Particularly, the status of DNA methylation has been proved to act as a key mediator in the expression of those miRNAs . One famOf note, recently, series of studies have additionally revealed that the presence of single-nucleotide polymorphism (SNP) in miRNA genes also participates in the regulation of miRNA expression and maturation during human pregnancy . For exaEvidence is emerging to suggest that a great deal of miRNAs are highly expressed in human placenta, and interestingly, some miRNA genes are expressed in a time-dependent and/or tissue-specific manner during different developmental stages of human placenta, which is in agreement with their functions in modulating placental development and trophoblast functions. Particularly, some miRNAs are specifically or preferentially expressed in the placenta, such as C19MC and C14MC clusters , which aRecent studies have clarified that kinds of miRNAs exert effects on human trophoblast cell proliferation, apoptosis, migration and invasion, suggesting human placental development is controlled by various miRNAs. In an in vitro study using the first trimester placental explants, small interfering RNA (siRNA)-mediated knockdown of Dicer significantly promotes cytotrophoblast cell proliferation and also significantly induces the expression of two molecules in pro-mitogenic signaling within cytotrophoblasts, including ERK and SHP-2 , indicatAs stated above, movement (including migration and invasion) of EVTs towards the maternal decidua and myometrium are fundamental for effective placentation ,112. In Aberrant expression levels of miRNAs have been both in vitro and in vivo detected in kinds of gestational complications, such as PE, FGR, GDM, and a number of studies have demonstrated the dysregulation of miRNA expression in compromised human pregnancies  with onset or first recognition during human pregnancy, which has emerged as one of the complications with high incidence during human pregnancy . SeveralIn addition to PE, FGR and GDM, miRNAs such as miR-365, miR-4497, miR-155-5p and miR-149 are found to be associated with early recurrent miscarriage ,176,177.Detection of specific miRNAs in different gestational stages and in the maternal circulation provides with the possibility that miRNAs may be used as pregnant-related biomarkers to monitor the status of human normal pregnancy and potential gestational diseases in clinic. However, quantification of miRNAs, particularly the exosome miRNAs, is challenging due to their small amount. Thus, it is important to improve current experimental methodologies and to hopefully make comparisons of the experimental data obtained with available databases on line as well as with in silico prediction models to achieve a complex view on the role of miRNAs in different gestational diseases and to further discover suitable biomarkers. Owing to the great work in past decades, we have obtained a better understanding of miRNAs in human pregnancy. Nevertheless, despite the exciting results on miRNA research in human placenta, our current knowledge on how the thousands of miRNAs contribute to human placental development and function in pregnancy processes is still very limited. Studies in the future are in need to continue to search for novel miRNA candidates, to investigate the regulation pattern of those miRNAs expression and to further decipher the molecular mechanisms underlying their regulation in human placenta.


The fisheries and aquaculture industries are some of the major economic sectors in the world. However, these industries generate significant amounts of wastes that need to be properly managed to avoid serious health and environmental issues. Recent advances in marine waste valorization indicate that fish waste biomass represents an abundant source of high-value biomolecules including enzymes, functional proteins, bioactive peptides, and omega-3 rich oils. Enzyme-assisted processes, for the recovery of these value-added biomolecules, have gained interest over chemical-based processes due to their cost-effectiveness as well as their green and eco-friendly aspects. Currently, the majority of commercially available proteases that are used to recover value-added compounds from fisheries and aquaculture wastes are mesophilic and/or thermophilic that require significant energy input and can lead to unfavorable reactions . Cold-adapted proteases extracted from cold-water fish species, on the other hand, are active at low temperatures but unstable at higher temperatures which makes them interesting from both environmental and economic points of view by upcycling fish waste as well as by offering substantial energy savings. This review provides a general overview of cold-adapted proteolytic enzymes from cold-water fish species and highlights the opportunities they offer in the valorization of fisheries and aquaculture wastes. The fisheries and aquaculture industries represent some of the major economic sectors in the world. A recent report by the Food and Agricultural Organization (FAO) indicated that the total world fisheries and aquaculture production  reached 177.8 million tons in 2019 and generated USD 406 billion in terms of total first sale value , which are found in the pancreatic juices and are highly active in the pyloric ceca and small intestine of fish, have been used in several industrial applications due to their high specificity as well as stability and activity under severe unfavorable conditions, such as alkaline pH and in the presence of surfactants or oxidizing agents . Some exEnzyme isolation and purification are complex processes, and generally rely on various techniques that are sequentially applied to achieve the required purity levels . Among tProteins, including enzymes, can be precipitated through the disruption of their conformations, which can be achieved through pH shift, ionic strength and/or the addition of water-miscible solvents. Shifting the pH of the medium can either cause protonation of certain groups in the protein (by decreasing the pH), dissociation of protons (by increasing the pH), or charge neutralization  . The latThe disruption of protein (or enzyme) macro-structures can also be achieved through the addition of significantly high amounts of salt  or through the addition of organic solvents, such as methanol, ethanol, butanol and acetone . The larPrecipitation through the addition of water-miscible solvents is generally attributed to the competition of protein and the solvent’s polar groups with water . If solvAqueous two-phase partitioning is a one-step, liquid–liquid purification approach based on affinity partitioning and is generally achieved by mixing polymer/polymer  or polymer/salt  with water . In geneIn downstream processing, ATPS represents the initial isolation and purification step, which is achieved by the partial elimination of impurities and the reduction of the working volume . The simAqueous two-phase systems has been reported to efficiently recover enzymes from fish wastes such as farmed giant catfish viscera , 75 and Membrane ultrafiltration is a well-established separation process which allows for both purification and concentration , 78. UltDespite the advantages of ultrafiltration, only a few research studies have investigated this membrane-based process for the isolation and separation of fish proteolytic enzymes , 83. TheSeveral potential biotechnological and industrial applications have been suggested for cold-adapted enzymes which have been extensively reviewed elsewhere , 23, 26.(i)In the production of fish protein hydrolyzates and flavoring compounds. In this respect, cold-adapted proteases have been reported to produce fish protein hydrolyzates with acceptable odor in addition to reducing the bitterness and favoring the release of small-size peptides with flavor-forming characteristics ,(ii)In the extraction of target ingredients (such as pigments and fish oils). For example, cold-adapted proteases have been shown to enhance the recovery of pigments  from shellfish wastes , 88,(iii)As meat tenderizing agents , and(iV)As rennet substitutes .Other potential industries where cold-adapted fish-derived proteases can find applications include the leather and textile industries [in which cold-adapted proteases can replace harmful chemical reagents ] as wellDespite the numerous possible applications of cold-adapted enzymes, only a small number have been tested in a real industrial setting. For instance, β-galactosidase, methylesterase, polygalacturonase, and glycogen branching enzyme have been assessed, respectively, in the hydrolysis of lactose present in milk, in fruit firming, in juice processing, and in bread production . So far,The high specific activity at low temperatures combined with the decreased thermal stability of cold-adapted fish-derived proteases are highly sought after characteristics in various industrial applications , 92. It Shrimps, crabs, and lobsters are popular seafood around the world . The proResearch and development on seafood waste valorization has been increasing in the last few years. However, the industrial and commercial implementations of the developed seafood waste valorization approaches are limited in comparison to the large number of research studies that have been carried out and the patents that have been awarded. Currently, rendering seafood waste into fishmeal is still the preferred valorization route, with an annual production of about 5 million tons , 100. ThThe future perspective of this research topic should center on (i) assessing whether the efficiency of fish-derived cold-adapted proteases in recovering value added products exceeds that of commercial proteases, which could in turn justify and increase the chances for the large-scale implementation of the process, (ii) the isolation and purification of the most promising cold-adapted fish-derived protease using eco-friendly, economic and yet effective extraction processes (such as ATPS) and (iii) the production of the most promising cold-adapted fish-derived protease using genetic engineering and recombinant expression tools.The author confirms being the sole contributor of this work and has approved it for publication.The author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


As editors of this Research Topic, it was our pleasure to examine a wide range of attractive articles and reviews within the field of food microbiology. In this editorial, we outline the major results and perspectives detailed within each of the accepted manuscripts. This Research Topic is composed of two review articles and four original research articles.Dutta et al.. This review examines various current methods, including proteomics, transcriptomics, and metabolomics, for the overall enhancement of the quality of food products via bacteriocin application. The matrix associated with food products requires the use of sophisticated technologies that aid with the extraction of the large amount of information required for the amelioration of food products. This paper offers an overview of bacteriocins in terms of their structure, chemical composition, metabolomics, and their practical use in food preservation.In recent years, the omic sciences have contributed significantly to the development of methods for understanding the impact of various ingredients and foods on the human body on a molecular level. Tools that have recently been used to investigate numerous components and metabolites that can be valuable in the context of human consumption, and in particular bacteriocins, are discussed in the review presented by Ghosh et al. presents an in-depth discussion of the application of clustered regularly interspaced short palindromic repeats interference (CRISPRi) in food preservation and manufacturing. In particular, CRISPRi-facilitated silencing of genes encoding regulatory proteins associated with biofilm production is considered to be a reliable approach to editing gene networks in various biofilm-forming bacteria, either via inactivation of biofilm-forming genes or via integration into the host genome of genes corresponding to antibiotic resistance or fluorescent markers.The review by Volvariella volvacea, a mushroom that is industrially grown in many tropical and subtropical regions, have been thoroughly investigated, little is known about the characteristics of degenerated strains. Zhao et al. investigated the results of 20 months of continuous subculturing of mycelia to obtain degenerated V. volvacea strains S1-S20. In this context, the authors measured the characteristics of the mycelia and fruiting bodies, the reactive oxygen species (ROS) content, and enzymatic activities in order to explore the physiological changes occurring in subcultured strains. Analysis of ROS content, lignocellulase and antioxidant enzyme activities, and gene expression via reverse transcription polymerase chain reaction (RT-PCR) indicated that strain degradation in this fungal species was accompanied by a reduction in the activity of substrate-degrading enzymes and an extreme accumulation of ROS. The latter further led to aging of the organism during successive mycelial subculturing and may have been responsible for strain degradation in V. volvacea.While the cultivation techniques, breeding techniques, and physiology of Yan et al. discuss and analyze the current state of knowledge on carotenoids, a group of natural pigments acting as precursors to vitamin A, produced by Sporobolomyces pararoseus. It should be noted that Geranylgeranyl diphosphate synthase (GGPPS) is considered to be a key enzyme in the carotenoid biosynthesis pathway. The authors describe the cloning of a cDNA copy of the GGPPS protein-encoding gene crtE from S. pararoseus NGR. The crtE full-length genomic DNA and cDNA are 1,722 and 1,134 bp, respectively, which consist of 9 exons and 8 introns. This gene encodes a protein of 377 amino acids with a predicted molecular mass of 42.59 kDa and a PI of 5.66. Identification of the crtE gene encoding a functional GGPPS was achieved using heterologous complementation detection in Escherichia coli. In vitro enzymatic activity experiments showed that CrtE utilizes farnesyl diphosphate as an allylic substrate for the condensation reaction with isopentenyl diphosphate (IPP), generating more of the unique product GGPP compared to other allylic substrates. The predicted crtE 3D model is analyzed in comparison with yeast GGPPS. The condensation reaction occurs in the cavity of the subunit, and three bulky amino acids  below the cavity prevent further extension of the product. The authors' findings provide a new source of genes for carotenoid genetic engineering. Furthermore, these findings improve the understanding of the synthetic pathway of carotenoids in S. pararoseus NGR and unveil a new gene target for further improvement of carotenoid production via genetic engineering.Remaining on the subject of antioxidant properties, Li et al. report on an attempt to screen for potential biomarkers in various aspects of Wolfiporia cocos. This mushroom is extensively utilized in traditional Chinese medicine and as a dietary supplement. Using HPLC, the authors identify three components, viz. dehydrotrametenolic acid, poricoic acid A, and pachymic acid, as key potential biomarkers. In addition, their integrated analysis suggests that these molecules are probable biomarkers for Poria and Poriae cutis. Interestingly, the proposed approach represents an original strategy for the study of potential biomarkers, with the potential to provide insight into the clinical applications and reasonable development and utilization of Poria and Poriae cutis.From the perspective of measurability and effectiveness based on fingerprints, machine learning, and network pharmacology, Zhu et al., the authors select two types of “green-covering” Tuqu (TQ) with a crucial function in generating light-aroma-type Baijiu (LATB), namely TQ with a non-red heart (NRH) and with a red heart (RH), for an exploration of the diversity of the microbial community through high-throughput sequencing (HTS). Their results exposed dissimilarity in the microbial communities of different types of TQ and led to the isolation of two Monascus species. Remarkably, HPLC did not identify the presence of citrinin, demonstrating that Monascus isolated from TQ does not represent a safety risk. Throughout the fermentation process, γ-aminobutyric acid content was found to be higher in the fermented grains of RH than in those of NRH. Through use of HTS and gas chromatography–flame ionization detection (GC-FID), the effects of the fortified strain Monascus on fungal microbial composition in TQ and flavor substances in Baijiu were examined, yielding LATB with varied flavor profiles. In addition, Monascus was found to exert an inhibitory effect on the growth of Saccharomyces and Aspergillus. The reported findings provide specialized fungal resources for screening of superior strains and improving the quality of TQ and the original liquor.In the investigation by AH and AM were involved in draft preparation. SS was involved in supervision and project administration, editing, and final version writing. All authors contributed to the article and approved the submitted version.