The role of obesity in the pathophysiology of respiratory virus infections has become particularly apparent during the current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, where obese patients are twice as likely to suffer from severe coronavirus disease 2019 (COVID-19) than healthy weight individuals. Obesity results in disruption of systemic lipid metabolism promoting a state of chronic low-grade inflammation. However, it remains unclear how these underlying metabolic and cellular processes promote severe SARS-CoV-2 infection. Emerging data in SARS-CoV-2 and Influenza A virus (IAV) infections show that viruses can further subvert the host’s altered lipid metabolism and exploit obesity-induced alterations in immune cell metabolism and function to promote chronic inflammation and viral propagation. In this review, we outline the systemic metabolic and immune alterations underlying obesity and discuss how these baseline alterations impact the immune response and disease pathophysiology. A better understanding of the immunometabolic landscape of obese patients may aid better therapies and future vaccine design. Evidencividuals . Data frividuals . These sividuals .In this review, we will discuss how obesity impacts viral shedding, propagation, host metabolism, inflammation and immunity. Furthermore, we highlight ongoing therapeutic approaches to improve COVID-19 patient survival in the obese.Obesity may play a role in prolonged viral shedding of infected individuals, potentially increasing transmission within the population. Viral shedding of IAV in obese adults can last 42% longer than lean individuals and in asymptomatic cases 104% longer , data coObesity may contribute to viral propagation by promoting the expression of the SARS-CoV-2 cell entry receptor angiotensin-converting enzyme 2 (ACE2) on a variety of cell types including bronchial epithelial cells , 18. ACEUpon viral infection, SARS-CoV-2 hijacks cellular metabolism for replication and production of new virions. SARS-CoV-2 infection in monocytes leads to an accumulation of intracellular lipids and an increase of proteins involved in lipid metabolism such as the fatty acid transporter CD36 and lipogenic transcription factors such as the peroxisome proliferator-activated receptor γ (PPARγ) and SREBP-1 . FurtherBesides palmitoylation, enveloped viruses up-regulate cholesterol metabolism . CholestDrugs targeting lipid metabolism present novel therapeutic tools for combating obesity-related viral infection through their central role in the viral infection cycle. Thus, statins and other lipid-lowering drugs represent a promising candidate for COVID-19 treatment in obese patients .In the following section, we discuss how obesity changes the host’s metabolic and immunological state during viral infections and how this may provide a potent environment for respiratory viral infections such as SARS-CoV-2.Enhanced adipose tissue deposition in the obese (particularly in the abdomen) not only creates alterations in abdominal pressure with inadequate lung function and reduced oxygen saturation , but als+ and CD8+ T cells, leading to increased viral spread with prolonged infection, lung damage and susceptibility to secondary bacterial infections [Obese individuals infected for example with IAV show delayed and attenuated innate and adaptive immune response with reduced numbers of activated and functional memory CD4fections . Titers + and CD8+ T cells (lymphopenia) and CD4+ T cells with Th17 and Th22 phenotypes represent impaired adaptive immunity and a pro-inflammatory phenotype [+ T cells, reduced cytotoxic CD8+ T cells [Impaired B and T cell responses are a hallmark feature of severe COVID-19 disease . Low naïhenotype , 56. Oth T cells  combined T cells . Activat T cells , thus co T cells . Obesity T cells . Thus, o T cells . During  T cells .In contrast, little is known about the effects of obesity on B cell function during infection. Adipose tissue-derived B cells from lean animals protect against peritoneal antigens via T cell-dependent class switching and hypermutation . ObesityLipid homeostasis is predominantly regulated by adipose tissues and the liver in order to provide cells with essential lipids for biosynthesis and energy metabolism. Many lipids, including cholesterol, are transported in lipoprotein complexes in blood to avoid lipotoxicity. These are crucial for immune and stromal cell function. For instance, macrophages rely on high-density lipoproteins (HDLs) to control cholesterol efflux . Obese iBesides cholesterol, other lipid species can directly impact on immune function such as derivates of arachidonic acid. This poly-unsaturated fatty acid is transformed in innate immune cells to lipid mediators known to promote inflammation such as prostaglandins. COVID-19 patients show a gradual decrease in the precursor arachidonate with increasing disease severity . This maMitochondria play a key role in cellular metabolism including tricarboxylic acid cycle, decarboxylation of fatty acids or β-oxidation to generate and sustain adenosine triphosphate (ATP) levels for cellular energy demands, while also being the main producer of reactive oxygen species (ROS). Accumulating evidence links the accelerated progression of COVID-19 to increased levels of inflammation leading to increased ROS production and cellular oxidative stress which in turns can trigger mitochondrial dysfunction . Indeed,Obesity causes profound metabolic alterations leading to mitochondrial dysfunction  which ca+ T cells depends on the uptake of exogenous free fatty acids [+ and CD8+ T cells from obese mice significantly increased the oxidative phosphorylation to glycolysis ratio in comparison to lean mice [In the context of acute viral infection, increased energy demand for effector T cell function is derived from a variety of fuel sources. Shifting from oxidative phosphorylation to glycolysis and production of ATP provides the fuel for increased metabolic demands. The conversion of effector T cells to long-lived memory T cells requires a switch back to oxidative metabolism with fatty acids as the fuel source , 95. Addty acids . Althougty acids . Treatmety acids . Consistty acids . Furtherty acids . In addity acids , 101 andty acids . After iean mice . Weight Obesity causes severe impairment of systemic lipid homeostasis due to calorie excess. Hypertrophic adipocytes create a state of systemic lipid imbalance and low-grade inflammation. This change in the host’s metabolic and inflammatory status renders immune cells dysfunctional by substantially altering mitochondrial structure and function. Consequently, immune cell metabolism shifts away from oxidative phosphorylation towards more pro-inflammatory glycolytic pathways, exacerbating SARS-CoV-2-induced inflammatory processes. It remains to be seen if obese patients can mount an effective memory B and T cell response to SARS-CoV-2 infection since dysfunctional adipose tissues in obese individuals may impair the necessary immunometabolic switch of memory cells towards FAO and consequently alter their reactivation potential. Previous studies examining influenza infections show that obesity impairs memory responses leaving the host more susceptible to reinfection. It remains to be seen whether obese patients are more likely to experience reinfection with SARS-CoV-2 over the coming years. Dyslipidemia may further promote viral replication through increasing ACE2 expression on adipocytes and epithelial cells.Although global health measures to reduce obesity may represent a long-term solution to reduce obesity-driven impairments in immune response to viral infections , patientFuture studies elucidating the metabolic and immunologic mechanisms of obesity and risk of SARS-CoV-2 infection and severe disease are warranted. Understanding these pathways at the molecular level may enable development of targeted therapeutic approaches and aid future vaccine design for the obesogenic host.Box 1: Why does obesity matter during COVID-19?Several studies underline the significant changes in lipid metabolism observed during viral infections, some of which are reminiscent of changes observed in obese uninfected individuals. It is clear that obese individuals are 2 times more likely to experience severe COVID-19 progression. This shows striking parallels to heightened risk of influenza-related hospitalization and disease severity. Obesity fundamentally alters the host’s metabolism and promotes obesity-associated inflammation, which has been linked in the context of influenza infections to increased viral replication and disease severity. Thus, obese individuals represent a more susceptible population group that requires particular attention in disease prevention and treatment during this pandemic.Box 2: What is the consensus on obesity and COVID-19?https://www.gov.uk/government/news/new-obesity-strategy-unveiled-as-country-urged-to-lose-weight-to-beat-coronavirus-covid-19-and-protect-the-nhs) [Obesity in the UK has been increasing over the past decades. Today, ∼30% of the UK population is classified as obese. Obesity increases the risk of other chronic diseases and makes individuals more susceptible to viral infections like influenza and as observed now during the SARS-CoV-2 outbreak. The UK government has recently acknowledged the necessity of tackling this issue and started promoting long-term public health measures (see the-nhs)  to decre


Drosophila. We showed previously that the Drosophila Fox gene jumeau (jumu) controls three categories of cardiac progenitor cell division—asymmetric, symmetric, and cell division at an earlier stage—by regulating Polo kinase activity, and mediates the latter two categories in concert with the TF Myb. Those observations raised the question of whether other jumu-regulated genes also mediate all three categories of cardiac progenitor cell division or a subset thereof. By comparing microarray-based expression profiles of wild-type and jumu loss-of-function mesodermal cells, we identified nebbish (neb), a kinesin-encoding gene activated by jumu. Phenotypic analysis shows that neb is required for only two categories of jumu-regulated cardiac progenitor cell division: symmetric and cell division at an earlier stage. Synergistic genetic interactions between neb, jumu, Myb, and polo and the rescue of jumu mutations by ectopic cardiac mesoderm-specific expression of neb demonstrate that neb is an integral component of a jumu-regulated subnetwork mediating cardiac progenitor cell divisions. Our results emphasize the central role of Fox TFs in cardiogenesis and illustrate how a single TF can utilize different combinations of other regulators and downstream effectors to control distinct developmental processes.Forkhead (Fkh/Fox) domain transcription factors (TFs) mediate multiple cardiogenic processes in both mammals and  Our previous work had identified the conserved cardiogenic roles of two Fox genes, jumeau (jumu) and Checkpoint suppressor homologue (CHES-1-like) in both the specification and subsequent division of progenitor cells in the Drosophila heart28.While at least eight Forkhead (Fkh/Fox) domain transcription factors (TFs) are required for proper cardiac development in mammalsjumu and CHES-1-like function in a mutually redundant manner to transcriptionally activate the expression of heartless (htl) and frizzled (fz), which respectively encode the receptors in a FGF-signaling pathway and a Wnt-signaling pathway required for cardiac progenitor specification; consequently, lacking both Fox genes results in a failure of much of the heart to be specified26. We also demonstrated that jumu and CHES-1-like mediate three distinct categories of cell division that generate the correct subtypes and numbers of cells constituting the heart—asymmetric cardiac progenitor cell divisions, symmetric cardiac progenitor cell divisions, and cell divisions at an earlier stage that produced the cardiac precursor cells—by regulating the activity of the conserved kinase Polo28. In addition, our investigations revealed that the TF Myb acts synergistically with Jumu, CHES-1-like, and Polo to mediate only two of these three categories of cardiac progenitor cell division: symmetric and cell division at an earlier stage27. In contrast, asymmetric cardiac progenitor cell division involved Jumu and CHES-1-like utilizing Polo to phosphorylate Partner of numb (Pon) and thereby bring about the localization of membrane-associated Numb protein to one pole of the dividing cell29.We showed previously that both 30, and that loss-of-function mutations in jumu or CHES-1-like significantly altered the expression levels of many known cardiac genes26. Taken together, these data indicate that the Fox TFs regulate a large number of genes in addition to polo, htl, and fz in order to mediate cardiogenesis.Additionally, we found that Fox TF binding sites were significantly enriched in the enhancers of genes expressed in the heartpolo, htl, and fz involved in the two distinct cardiogenic processes—cardiac progenitor specification and cardiac progenitor cell division—that we have discovered as being mediated by the Fox TFs to date?Collectively, these observations raise three intriguing developmental questions. First, are additional Fox TF-regulated genes besides jumu and CHES-1-like were both seen to be simultaneously regulating the activity of each relevant downstream target gene  whenever any one of these target genes was characterized as mediating a cardiogenic process. Thus, a particularly germane question is whether there are any downstream cardiogenic targets and, by extension, associated pathways or subnetworks, that are exclusively regulated and mediated by one, but not the other, of these two Fox TFs.Second, Myb itself acts in concert with both Fox genes at the same hierarchical level to mediate only two of the three categories of cardiac progenitor cell divisions, polo, the downstream target of both jumu and CHES-1-like, is utilized for all three. Thus, another pertinent question is whether every Fox TF-regulated gene utilized in cardiac progenitor cell division also plays critical roles in all three categories of cell division or is necessary for only certain specific subsets.Third, while nebbish (neb) is activated by only one Fox gene, jumu; that neb is required in conjunction with polo and Myb to mediate cardiac progenitor cell divisions; and that neb is necessary for only two of the three categories of cardiac progenitor cell division—symmetric and cell division at an earlier stage—thereby extending our understanding of the Fox-regulated subnetworks mediating cardiogenesis.Here we show that the kinesin-encoding gene jumu, and embryos homozygous for a null mutation in CHES-1-like at embryonic stages 11 and early 12, i.e. when cardiac progenitor specification and cell division occur in Drosophila26. Reasoning that cardiogenic genes regulated by a Fox TF are likely to exhibit differential expression between the heart-producing mesoderm in wild-type and Fox loss-of-function mutant embryos, we compared the transcription expression profiles between mesodermal cells from wild-type embryos and the Fox gene mutants. We found that neb had its expression levels significantly downregulated in jumu null mutants  but remained essentially unaffected in CHES-1-like null mutants .One of our goals was to discover downstream genes mediating cardiogenic processes, if present, that were regulated by one, but not the other, of the twin Fox TFs Jumu and CHES-1-like. We had previously used flow cytometry and Affymetrix microarrays to obtain genome-wide transcription expression profiles of purified mesodermal cells from wild-type embryos, embryos homozygous for a null mutation in neb expression, we used the pan-mesodermal twi-GAL4 driver to knock down either jumu or CHES-1-like via RNA interference (RNAi) exclusively in the mesoderm. We then assessed and compared the resulting neb transcript levels at stages 11–12 with that in control embryos by reverse transcription quantitative real-time PCR (RT-qPCR). Since jumu and CHES-1-like are also expressed in tissues other than the mesoderm31, null mutations in the Fox genes could potentially also affect neb expression levels in these non-mesodermal tissues. Utilizing exclusively mesoderm-targeted RNAi knockdowns of these Fox genes instead of null mutations in jumu or CHES-1-like thus ensured that any detected alterations in neb transcript levels in total RNA were due solely to the effects of the Fox genes in the mesoderm. Our RT-qPCR assays revealed a decrease in neb expression levels in mesoderm-targeted jumu knockdowns compared to that in control embryos containing only the twi-GAL4 driver, but detected no such reduction in mesoderm-targeted CHES-1-like knockdowns -expressing contractile cardial cells (CCs) and an outer sheath of Zn finger homeodomain 1 (zfh1)-expressing nephrocytic pericardial cells. From anterior to posterior, the cardial cells consist of two Seven up-expressing CCs (Svp-CCs) followed by four Tinman-expressing CCs (Tin-CCs) in every repeating hemisegment. These cardial cells are surrounded by a larger number of pericardial cells, which includes two Seven up-expressing PCs (Svp-PCs) that are located laterally to the CCs in each and every hemisegment. The different cellular subtypes comprising these cardial and pericardial cells arise through a stereotyped series of cardiac progenitor cell divisions35. Specifically, cell division at an earlier stage ensures that there are two Svp precursor cells per hemisegment. Subsequently, the two Svp-CCs in wild-type cardiac hemisegments arise by two asymmetric progenitor cell divisions from these two Svp precursor cells, with each cell division generating one Svp-CC and one Svp-PC , corresponding to symmetric cell division defects, and in the fraction of hemisegments with either one or three pairs of Svp-CCs and Svp-PCs (P = 0.016), corresponding to earlier cell division defects affecting the number of Svp precursors  from that in wild-type embryos  directed by the TinD-GAL439 and Hand-GAL440 drivers and examined the resulting embryos for alterations in expected cardial cell numbers consistent with errors in cardiac progenitor cell divisions. Staining with appropriate antibodies showed hemisegments with localized changes in the number of Tin-CCs corresponding to symmetric cell division defects and Svp-CCs corresponding to defective cell division at an earlier stage  than the additive effects of both the neb single heterozygotes and the jumu single heterozygotes Exel6157/+double heterozygotes over the additive sum of those in the component nebMI0225/+and jumuDf(3R)Exel6157/+single heterozygotes is barely significant (P = 0.0429)  Figs. . Our resjumu brings about all three categories of cardiac progenitor cell divisions by regulating the activity of Polo kinase28, we used similar genetic interaction assays next to assess whether neb and polo also function through the same genetic pathways. Our results revealed highly significant synergistic genetic interactions between neb and polo for both symmetric cell divisions and earlier cell divisions , but no significant interactions in the case of asymmetric cardiac progenitor cell divisions (P = 0.117)  Figs. .Myb has been shown to regulate polo expression41, and act synergistically with jumu to mediate only symmetric and earlier Svp precursor-determining cardiac progenitor cell divisions27, we next addressed whether neb works in concert with Myb via genetic interaction assays, and in which classes of cardiac progenitor cell divisions. Significant synergistic genetic interactions between neb and Myb were also detected in the case of both symmetric cell divisions and earlier cell divisions , but not for asymmetric cell divisions (P = 0.340)  Figs. .neb is necessary for only two of the three categories of cardiac progenitor cell divisions, symmetric and earlier, and that it mediates these two types of cell divisions by working in concert with jumu, Myb, and polo through the same genetic pathways.Taken together, these results and our initial findings show that jumu-regulated cardiogenic processes that we had discovered, cardiac progenitor specification and cell division, are also regulated by another Fox TF, CHES-1-like. Furthermore, the downstream genes used for each of these processes, htl and fz in the case of cadiac mesoderm specification, and polo in the case of cardiac progenitor cell divisions, are each also regulated by both jumu and CHES-1-like28. neb, however, provides an exception to this trend because, based on our expression profiling data, it is transcriptionally regulated only by jumu, and not by CHES-1-like. Does the observation that CHES-1-like does not regulate neb imply that neb functions completely independently of CHES-1-like, or are they both components of the same genetic subnetwork?As described previously, both of the neb and CHES-1-like in mediating cardiac progenitor cell divisions, based on the premise that such interactions are likely to be synergistic if neb and CHES-1-like function in concert in the same pathways. The frequency of cardiac progenitor cell division defects in CHES-1-like1/+; nebMI0225/+ double heterozygotes was not significantly different from the additive sum of those of the CHES-1-like1/+ and nebMI0225/+ single heterozygotes during asymmetric (P = 0.266), symmetric (P = 0.721), or earlier Svp precursor-determining cell divisions (P = 0.530)  Figs. . The lacjumu activates neb and that neb is specifically required in the cardiac mesoderm for mediating symmetric and earlier Svp precursor-determining cell divisions, i.e. two of the three categories of jumu-regulated cardiac progenitor cell divisions. The most parsimonious hypothesis that can explain these observations is that jumu transcriptionally upregulates neb in the cardiac mesoderm to bring about symmetric and earlier cardiac progenitor cell divisions, and that in jumu loss-of-function mutations the ensuing reduction in neb expression levels in this tissue results in defects in only these two types of cell divisions. However, the nature of neb expression prevented us from qualitatively assessing via in situ hybridization assays whether the reduction of neb transcript levels in the entire mesoderm in jumu mutants reflected a reduction of neb levels specifically in the cardiac mesoderm.Our results so far show that neb specifically in the cardiac mesoderm in jumu loss-of-function mutants under the control of the TinD-GAL4 driver . Defects in Svp precursor-determining cell divisions are also rescued, albeit with borderline significance (P = 0.0632). In contrast, no significant difference is detected in asymmetric cell division defects between jumu mutants alone and jumu mutants expressing full-length neb (P = 0.781)  Fig. . Collecthtl and fz as Fox TF-regulated genes that mediate cardiac progenitor specification and polo as yet another Fox TF-regulated gene that mediates three distinct categories of cardiac progenitor cell division28. In this study, we identify another Fox TF-regulated downstream gene, neb, which also mediates cardiac progenitor cell divisions. The previously characterized Fox downstream targets htl, fz, and polo are each regulated by both jumu and CHES-1-like simultaneously. Our expression profiling results indicate that neb, in contrast, is transcriptionally regulated only by Jumu, and not by CHES-1-like. This independence from CHES-1-like regulatory control is also supported by neb exhibiting synergistic genetic interactions with jumu in cardiac progenitor cell division subnetworks, but not with CHES-1-like.Our previous work had identified the roles of neb by Jumu specifically in the cardiac mesoderm that is necessary for proper cardiac progenitor cell divisions. It is possible that Jumu may also activate neb expression at other mesodermal domains besides the cardiac mesoderm: our expression profiling was based on the entire mesoderm, and in situ hybridization assays showed neb expression in subsets of the somatic mesoderm in addition to the cardiac mesoderm. However, the twin observations that cardiac mesoderm-specific knockdown of neb partially phenocopies jumu loss-of-function cardiac progenitor cell division defects and that cardiac mesoderm-specific ectopic expression of neb partially rescues jumu loss-of-function cell division defects demonstrate clearly that jumu mediates these cardiac progenitor cell division defects by activating neb expression specifically in the cardiac mesoderm.We showed further that it is the activation of jumu, CHES-1-like, and polo are required for all three categories of cardiac progenitor cell division—asymmetric cell divisions, symmetric cell divisions, and cell divisions at an earlier stage that produce the Svp precursor cells—Myb is required for only the two latter classes28. In this study, we discovered that neb, like Myb, is also required for only the symmetric and earlier cardiac progenitor cell divisions, not asymmetric cell divisions. Furthermore, while neb exhibits no synergistic genetic interactions with CHES-1-like in any of the three classes of cardiac progenitor cell divisions, it displays synergistic genetic interactions with Myb and polo exclusively in symmetric and earlier Svp precursor-determining cell divisions. And while neb and jumu do show synergistic genetic interactions in all three categories of cardiac progenitor cell divisions, the interaction in the case of asymmetric cell divisions is barely significant. Finally, we find that ectopic cardiac mesoderm-specific expression of neb partially rescues symmetric and earlier cardiac progenitor cell division defects in jumu loss-of-function mutants, but not asymmetric cell division defects. Given also prior studies showing synergistic genetic interactions between Myb, jumu, and polo in these same two classes of cardiac progenitor cell divisions27, and the regulation of polo by both jumu and Myb41, our data thus suggests the presence of an additional CHES-1-like-independent, jumu-regulated pathway involving Myb, polo, and neb that mediates only symmetric and earlier cell divisions. This pathway both expands our prior model of Fox TF-regulated cardiogenic processes  and pavarotti (pav) are also activated by Jumu in the mesoderm   mediating neb transcription and suggest that neb might be a direct transcriptional target of Jumu as well as of Myb.Another intriguing question is whether the activation of 28 that FoxM1 is the functional ortholog of jumu in mammals because FoxM1 regulates Plk1, the mammalian ortholog of polo48, because FoxM1 and Myb function as synergistic master regulators of key genetic programs of human B cell proliferation in the germinal center49, and because mutations in FoxM1 exhibit cardiac phenotypes—highly irregular orientation of cardiomyocytes with enlarged polyploid nuclei—that are similar to those in jumu mutants10. Given our discovery of a jumu-regulated pathway for cell division that involves Myb, polo, and neb in Drosophila, and possible cis-regulatory regions of neb that bind both Jumu and Myb, it was very interesting to find that both mammalian FoxM1 and B-Myb bind to the promoter of the neb ortholog Kif14 and activate its transcription in breast cancer cell lines51. And, not surprisingly, Kif14 is considered to play a role as an oncogene in cancer types as varied as breast, lung, liver, gastric, colorectal, ovarian, cervical, and prostate cancers in addition to glioma, medulloblastoma, and retinoblastoma64.We have previously suggestedneb and its ortholog Kif14 is quite crucial, involving not only a conserved complex mediating cytokinesis in both flies and mammals65, but also its potentially conserved regulation by Fox and Myb TFs. It remains to be seen whether the Fox TF-regulated role of this kinesin is also conserved in cardiac progenitor cell divisions in mammals. The observation that the Meckel–Gruber syndrome linked to some mutations of human Kif14 is occasionally found to be also associated with congenital heart defects66 suggests that this may indeed be the case.Taken together, these data suggest that the evolutionary role of jumuDf(3R)Exel6157  and CHES-1-like1 28; nebk05702 [FlyBase ID: FBal0043429]42; nebMI0225 [FlyBase ID: FBal0249290]; UAS-nebRNAi ; UAS-neb ; svp-lacZ 33; polo10 67; MybMH107 [FlyBase ID: FBal0141652]68; UAS-Dcr-2 69; TinD-GAL4 39; and Hand-GAL4 40. They were maintained over FM7c, ftz-lacZ, CyO, ftz-lacZ, and TM3, ftz-lacZ balancers when they could not be homozygosed before crossing. Relevant embryos resulting from these crosses were distinguished from their siblings by the absence of anti-β-galactosidase staining in the ftz-lacZ pattern of the balancers. CHES-1-like and Myb heterozygotes were distinguished from hemizygotes by both positive staining for anti-Sxl since they were female and the absence of anti-β-galactosidase staining in the ftz-lacZ pattern. The same anti-β-galactosidase staining, along with anti-Mef-2 staining, was also used to distinguish the Svp-CCs and Svp-PCs except in the case of RNA interference assays. The nebMI0225 allele, a weak hypomorphic mutation that fails to complement the nebk05702 null allele, was used in genetic interaction assays because it allowed cell division defects to be assessed with increased sensitivity. The genotypes of all the embryos used for counting cell division defects  construct targeted to the cardiac mesoderm using both TinD-GAL4 and Hand-GAL4 drivers simultaneously. The efficiency of knockdowns was enhanced with UAS-Dcr-2. Cell division defects were counted in the neb knockdown and controls  by staining with anti-Mef2 and anti-Svp to identify Tin-CCs and Svp-CCs.RNA interference knockdown of jumu and CHES-1-like used in these assays are included in Supplementary Method Details of the RT-qPCR methodology and the mesoderm-targeted RNA interference knockdown of 28. The following primary antibodies were used: rabbit anti-Mef2 , mouse anti-β-galactosidase , chicken anti-β-galactosidase , mouse anti-Svp , and mouse anti-Sxl . Fluorescent microscopy was performed on a Zeiss AxioImager with Apotome. Z-stacks of entire stage 16 embryonic hearts were scanned with a 40X objective and 0.31 µm steps, and all planes for each z-stack were examined to count cells and determine cell division defects. Cell counting and assessment of cell division defects were performed blind  to avoid any potential bias. For all quantitative studies, cells in 179 or more hemisegments were counted for each genotype.Embryo fixation, riboprobe synthesis, in situ hybridization, and fluorescent immunohistochemistry were performed as described previouslyp-values73.Comparison of cell division error rates between genotypes was done using regression models with the response variable being the proportion of hemisegment errors for each embryo. Due to violation of regression assumptions, e.g., non-normality and heteroscedasticity, permutation (randomization) tests were used to obtain reliable nebk05702 and wild-type, the following general linear model was used:nebk05702 and 0 otherwise. To obtain a permutation p-value for testing 74. In order to obtain highly reproducible p-values, For comparing rates between two genotypes, for example neb and Myb, a general linear model allowing for interaction was used:nebMI02225 mutation and MybMH107 mutation. Since synergism is present only if 75.For determining if cell division error rates are non-additively related to two gene mutations, for example, to detect synergistic interaction between Supplementary Information.Supplementary Table 1.Supplementary Table 2.Supplementary Table 3.


Based on initial clinical data, it was suggested that patients with vasculitis who were immunosuppressed, would have a more severe COVID-19 infection. Here we present a case of a young 26-year old lady with granulomatosis with polyangiitis (GPA) on rituximab who developed COVID-19 infection while on active GPA treatment. Her COVID-19 infection confirmed on PCR serology, has been protracted but non-fulminant. She did not require mechanical respiratory support. At the same time her GPA remained active and worsened requiring further immunosuppression after she developed mild pulmonary haemorrhage. She is currently still receiving vasculitis treatment.A 26-year-old lady with a background history of obstructive sleep apnoea and fibromyalgia was diagnosed with ENT-limited GPA in 2017. She was initially treated with azathioprine then methotrexate, and later switched to Rituximab in 2018 after she developed organ-threatening manifestations with bilateral hearing loss. She was stable on periodic infusions of rituximab at 6 to 9-monthly intervals and did not develop other organ-threatening features.nd dose of rituximab after it had been delayed by about 2 weeks. She had been afebrile after the acute COVID-19 infection and her persistent positive results were explained as related viral shedding over a period of 8 weeks.She had been given one dose of rituximab for a flare of her GPA. In between rituximab doses, she was admitted with acute COVID-19 infection with related pneumonia and treated with antibiotics, fluids, and oxygen. Shortly after discharge, she was readmitted with worsening symptoms of non-resolving COVID-19 pneumonia which was evident on chest x-ray and levofloxacin treatment was initiated. Her condition improved and she was discharged. No mechanical respiratory support was required. She had her 2One week later, she represented to hospital with fever, cough and shortness of breath, and her blood results showed a remarkable rise in inflammatory markers, including a CRP of 242. She was treated for non-resolving COVID-19 pneumonitis with worsening chest x-ray features. After hospital discharge, her GPA continued to flare with persistent epistaxis with nasal crusting. She also had worsening inflammatory arthritis with purpuric rash on her legs. An ENT review confirmed nasal septum perforation, but no renal involvement was found. Additional cyclophosphamide was commenced via the day-case unit. Her SARS-CoV-2 serology was negative prior to commencing cyclophosphamide. She is now SARS-CoV-2 positive after two doses of cyclophosphamide, but she is afebrile and stable.COVID-19 infection carries a high mortality rate in patients with multiple co-morbidities, but recent literature suggests that patients on immunosuppressants may not actually have fulminant COVID-19 disease. This case illustrates the challenges of treating active vasculitis in the context of ongoing COVID-19 infection. Her vasculitis remained active requiring escalation of immunosuppression with caution, while she was concomitantly fighting SARS-CoV-2 and superadded bacterial infection. A similar case has been published by Guilpain et al of a 52-year-old woman with PR3-ANCA vasculitis on maintenance therapy with rituximab and low-dose prednisone who developed COVID-19 infection. They reported milder evolution of COVID-19 infection in comparison with previous reports.It is now well known that some disease-modifying anti-rheumatic drugs (DMARDs) such as tocilizumab, hydroxychloroquine and tofacitinib could suppress the cytokine profile seen in severe COVID-19 infection. In addition, several case reports have even reported possible protective effect of immunosuppressants against severe complications of COVID-19 in patients with rheumatological and non-rheumatological conditions. Another complexity in this case was monitoring the disease progression, since both COVID-19 and GPA can have similar findings on chest CT scan of ground glass opacity. In order to better understand the role of immunosuppressants in rheumatological patients with COVID-19 infection, more data is required, currently European League Against Rheumatism (EULAR) is collecting data to monitor and report outcomes of COVID-19 in adult and paediatric population, this will provide invaluable insight for Rheumatologists.      Case report - Key learning points This case poses a challenge for Rheumatologists in managing a patient with active vasculitis and concomitant COVID-19 infection due to limited data available literature. It has also stressed the importance of working in a multidisciplinary team when managing such complex patients. Importance of continuous surveillance of patients receiving immunosuppressive therapy is advised due to possible increased risk to SARS-CoV-2.


The coronavirus disease 2019 (COVID-19) pandemic is the largest health crisis ever faced worldwide. It has resulted in great health and economic costs because no effective treatment is currently available. Since infected persons vary in presentation from healthy asymptomatic mild symptoms to those who need intensive care support and eventually succumb to the disease, this illness is considered to depend primarily on individual immunity. Demographic distribution and disease severity in several regions of the world vary; therefore, it is believed that natural inherent immunity provided through dietary sources and traditional medicines could play an important role in infection prevention and disease progression. People can boost their immunity to prevent them from infection after COVID-19 exposure and can reduce their inflammatory reactions to protect their organ deterioration in case suffering from the disease. Some drugs with in-situ immunomodulatory and anti-inflammatory activity are also identified as adjunctive therapy in the COVID-19 era. This review discusses the importance of COVID-19 interactions with immune cells and inflammatory cells; and further emphasizes the possible pathways related with traditional herbs, medications and nutritional products. We believe that such pathophysiological pathway approach treatment is rational and important for future development of new therapeutic agents for prevention or cure of COVID-19 infection. The coronavirus disease 2019 (COVID-19) outbreak is the greatest major threat experienced by the human race in living memory Patients with SARS-CoV-2 experience a clinical spectrum, from mild/asymptomatic forms to acute respiratory distress syndrome (ARDS) requiring ventilator support and admission to an intensive care unit (ICU). Clinical symptoms vary and include respiratory involvement to damage to multiple organs, including the heart, liver, and kidney and organs of the gastrointestinal tract, among others. Ten to twenty percent of symptomatic patients experience disease progression and 3-5% require intensive care unit (ICU) admission Figure SARS-CoV-2 enters the human lung, heart and kidney cells through the binding of its spike (S) proteins to angiotensin-converting enzyme-2 (ACE2) receptors on host cells Patients with severe CoV-19 infection further experience a systemic inflammatory response and acute respiratory distress syndrome (ARDS), which results from “cytokine storm syndrome” + T cells are noted among severe COVID-19 patients A principal defense against SARS-CoV-2 involves both cell and antibody mediated immunity. Although serum antibodies are detected for approximately 2 weeks in all patients Heme oxygenase (HO-1) is an antioxidant enzyme that cleaves heme into carbon monoxide, ferrous iron and biliverdin, and these downstream products limit inflammation and oxidative stress Table 1). The possible underlying mechanisms regulated by these medicines during the COVID-19 era are depicted in Figure Generally, therapeutic options for SARS-CoV-2 infection should focus on vaccines to enhance immunity and medications to modulate the immune system, suppress inflammation, disturb virus-cell interactions, inhibit viral replication, etc. At present, no vaccine is available against COVID-19. Infected patients are currently treated with antivirals, anti-inflammatories, herbal medicines, plasma exchange, etc. . It is a yellow pigment of turmeric and a primary component of curry and the flavanol found in green tea. Curcumin improves neurodegenerative disorders by increasing NF-E2-related factor 2 (Nrf2)/heme oxygenase 1 (HO-1) protein expression and decreasing the apoptosis of PC12 cells Another natural phenol mostly studied for its antiviral effects is curcumin, a phenolic acid extracted from the rhizome of N. sativa L. (black seed) has been used primarily as a traditional medicine for a variety of diseases, including skin diseases, bronchial asthma, gastrointestinal disorders, toothache, diabetes mellitus, hypertension, etc. N. sativa seeds not only have antioxidant N. sativa L. improves lung inflammation by promoting a balance between pro- and anti-inflammatory pathways through modulatory actions on interleukin-4 (IL-4) and interferon-γ N. sativa oil exhibits antiviral effects by promoting the upregulation of both innate immunity (splenic M & phi expression) and adaptive immunity (the stimulation of the CD4+ T lymphocytes) in a murine cytomegalovirus model N. sativa seed and its active compounds are being extensively studied in COVID-19 patients. A recent molecular-docking-based study N. sativa, nigellidine and α-hederin, serve as natural inhibitors of SARS-CoV-2 N. sativa and Zn combined supplementation in COVID-19 patients was proposed on the basis of the hypothesis that the bioactive agents of N. sativa, thymoquinone and nigellimine block SARS-CoV-2 entry into pneumocytes, enhance zinc (Zn) uptake by cells and enhance human immunity. The immune-boosting activities of Zn are pleiotropic and participate in the activation of adaptive and acquired immunities, as well as intracellular antioxidant activities. On the other hand, the availability of Zn to pneumocytes is crucial in COVID-19 patients because Zn inhibits viral entry, blocks polyprotein processing N. sativa and Zn supplementation might represent a complementary approach to antiviral treatment against COVID-19 and needs additional clinical trials.Recently, Since patients at greater risk for SARS-CoV-2 infection have common comorbidities, whether their routine medications are associated with COVID-19 severity is an interesting topic. Among these, statins, which are lipid-lowering drugs, are considered possible agents for their pleiotropic anti-inflammatory effects. The cholesterol within lipid rafts in the viral envelope is important for viral entry of coronaviruses, including SARS-CoV, and depleting cholesterol results in a significant reduction in viral mRNA Another consideration for statin therapy in COVID-19 patients is its antithrombotic activity. Markedly elevated D-dimer levels and a high risk of thrombogenicity were noted among critically ill COVID-19 patients Melatonin, the primary pineal gland hormone, is a regulator of circadian and seasonal rhythms that is known for its anti-inflammatory and immunomodulatory actions Based on recent data, COVID-19 most severely affects those aged 60 years' and above, males, and those with comorbid conditions in vivo and in vitro studies consider the use of indomethacin in COVID-19 era. Amici et al revealed that in in vitro studies of monkey VERO cells (SARS-CoV) and in in vivo studies of dogs , indomethacin significantly reduced both SARS-CoV and CCoV by inhibiting viral RNA synthesis Indomethacin is a potent anti-inflammatory agent that non-selectively inhibits cyclooxygenase (COX)-1 and -2 enzymes and is mostly used to treat inflammatory conditions. Indomethacin exerts anti-inflammatory actions through the inhibition of TNF, IL-6 and superoxide free radicals Excess intracellular iron may promote excessive oxidative and nitrosative stress, which may correlate with ARDS and pulmonary fibrosis Vitamin D deficiency is a known pandemic and global public health problem that varies based on age, ethnicity, and latitude. Aged, obese, and dark-skinned populations have higher risk for vitamin D deficiency. Environmental factors, including a lack of or reduced r sun (UV-B) exposure, living with air pollution and smoking, are attributed to vitamin D deficiency. The presence of comorbid conditions, such as sepsis, diabetes mellitus, chronic respiratory disease, and cancer, are closely related to vitamin D deficiency An analysis of community outbreaks of COVID-19 has revealed that regions with certain latitude, temperature, and humidity are more prone to the spread of infection. The virus is thermolabile, and less sunlight, lower temperatures and decreased humidity seem to be favorable for COVID-19 Our previous study demonstrated that vitamin D supplementation efficiently increased serum antimicrobial cathelicidin levels, which paralleled increased serum 25-hydroxyvitamin D (25D) levels in uremic hyperparathyroidism patients Adequate vitamin D supplementation is also required for reducing RAS activity and increasing ACE2 concentrations in acute lung injury. In other words, adequate vitamin D supplementation induces the ACE2/Ang‐(1‐7) axis and suppresses the renin and ACE/Ang II/AT1R axis Vitamin C, especially at higher doses, acts as a potent antioxidant with immunomodulatory actions and significantly accumulates within immune cells N. sativa should be used in combination with Zn to enhance Zn entry into and its effects within pneumocytes. However, it is not clear how to use such a combination or the doses to use in different COVID-19 populations. Black seed oil at doses of 40-80 mg/kg/day is used safely as an adjunctive therapy; however, the Zn recommended daily allowance (RDA) varies according to age, sex, and general health conditions. Zn doses above the RDA are also dangerous because of toxicity. Therefore, future clinical studies on the effects and doses of Zn combined with chloroquine or N. sativa in different COVID-19 populations is needed.As previously described, Zn supplementation is considered important for its immune-boosting activities against various viral infections. However, oral supplementation alone is not sufficient to promote Zn availability in infected pneumocytes. Chloroquine and active ingredients of The demographic distribution and severity of the COVID-19 outbreak vary around the world. Whether such distribution is associated with dietary habits, the use of traditional and herbal medicines, differences in geographical distribution or vitamin or mineral deficiencies is still unknown. In this brief review, we discussed traditional health remedies, drugs, vitamins, and minerals with possible use as adjunctive therapies in the COVID-19 era. This is important since we are still experiencing uncontrollable COVID-19 spread and currently have no vaccine or curative medicine. Current evidence does not support the use of such adjunctive treatments in COVID-19; however, we eagerly await results of the rigorous clinical trials on the efficacy and safety of therapies that slow viral spread and improve outcomes.The treatment of COVID-19 is still unclear until now. However, people can boost their immunity to prevent them from infection after COVID-19 exposure and can reduce their inflammatory reactions to protect their organ deterioration in case suffering from the disease. This review discusses the herbs, medications and nutritional compounds possibly improve their immune systems and regulate the inflammatory reactions related with COVID-19 infection. Although many topics saturated with possible COVID-19 treatments, in this review, we want to convince our readers the importance of COVID-19 interactions with immune cells and inflammatory cells; and further emphasize on the possible pathways related with traditional herbs and nutritional products. Definitely, we need randomized clinical studies to prove the effectiveness of mono or combined therapies. To conclude, we believe that such pathophysiological pathway approach treatment is rational and important for future development of new therapeutic agents for prevention or cure of COVID-19 infection.


Finally, we evaluate the therapeutics that may best prevent the onset or spread of pathology in ALS and discuss what lies on the horizon for treating this currently incurable disease.Amyotrophic lateral sclerosis (ALS) is characterized by the progressive degeneration of the motor neurons that innervate muscle, resulting in gradual paralysis and culminating in the inability to breathe or swallow. This neuronal degeneration occurs in a spatiotemporal manner from a point of onset in the central nervous system (CNS), suggesting that there is a molecule that spreads from cell-to-cell. There is strong evidence that the onset and progression of ALS pathology is a consequence of protein misfolding and aggregation. In line with this, a hallmark pathology of ALS is protein deposition and inclusion formation within motor neurons and surrounding glia of the proteins TAR DNA-binding protein 43, superoxide dismutase-1, or fused in sarcoma. Collectively, the observed protein aggregation, in conjunction with the spatiotemporal spread of symptoms, strongly suggests a prion-like propagation of protein aggregation occurs in ALS. In this review, we discuss the role of protein aggregation in ALS concerning protein homeostasis (proteostasis) mechanisms and prion-like propagation. Furthermore, we examine the experimental models used to investigate these processes, including  A major pathological component of neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease, frontotemporal lobar degeneration (FTLD), and amyotrophic lateral sclerosis (ALS) is the prion-like propagation of misfolded and aggregated proteins in the central nervous system ; however, it can be converted into a β-sheet-rich pathogenic conformation (PrPSc) that can recruit and convert normal PrP to become pathogenic PrPSc through a template-directed manner  containing many chaperones due to the role it plays in protein synthesis. Protein disulfide isomerases (PDI) are a family of molecular chaperone proteins, localized primarily to the ER, that have oxidoreductase activity, which allows them to reduce and oxidize disulfide bonds in the proteins they are chaperoning  is characterized by the progressive degeneration of motor neurons in both the motor cortex, brain stem, and spinal cord  repeat expansions in the C9ORF72 gene, which result in the transcription of large (tens to thousands of repeats) hexanucleotide repeat RNA molecules and subsequent repeat-associated non-AUG (RAN) translation into dipeptide repeat (DPR) proteins , Pro-Gly (PG), Pro-Arg (PR), Gly-Ala (GA), and Pro-Ala (PA) polypeptides. These DPRs are thought to elicit different levels of toxicity and react differently within the cell based on their physicochemical properties , accounting for roughly 90% of cases. The remaining cases are familial (fALS) and, although some of the underlying genetic causes remain unidentified, are typically associated with a family history of the disease . UBQLN2 is an fALS-associated protein responsible for many interactions that facilitate protein degradation in vitro study of purified proteins and cultured cells, as well as in vivo in invertebrate models  and mouse models. For reviews that incorporate zebrafish (Danio rerio) models, see Babin et al.  and the proteins  in an assay, a more fundamental understanding of the processes underlying protein misfolding and prion-like propagation can be achieved.E. coli) or yeast  and electrostatic loop (loop VII), being responsible for the coordination of metals or guidance of superoxide substrate to the enzymatic site, respectively. Furthermore, a conserved intramolecular disulfide, that stabilizes the tertiary structure and promotes dimerization, is formed between residues Cys57 and Cys146  prevents excessive FUS fibril formation in condensation experiments in vitro  is resistant to detergent denaturation and proteolytic degradation would be useful to determine if purified FUS can form pathogenic amyloids. For a visual summary of the assays that can be performed with purified protein, see Indeed, current understanding of ALS as a prion-like disorder is supported strongly by experimentation of both SOD1 and TDP-43, however, experimentation with FUS is in early stages , HeLa cells, SH-SY5Y cells, Neuro-2a, and NSC-34, however, other cell lines are used too. NSC-34 cells are a hybrid cell line generated from a fusion of murine neuroblastoma cells and murine embryonic spinal cord enriched in motor neurons  disease-associated mutant forms of SOD1 are significantly more aggregation-prone than wild-type SOD1  provide unique opportunities to investigate the pathological role of ALS-associated protein aggregates. Here we will discuss models for neurodegeneration using C. elegans has been used for decades in the study of neuronal development  with expression restricted to specific cells or tissues, including the remarkable ability to express transgenes in individual neurons. Also, the transparent nature of C. elegans enables imaging of fluorescence-tagged proteins in specific tissues/cells within a whole organism  C. elegans transgenic lines to investigate the mechanisms through which ALS-associated mutations in SOD1, TDP-43, and FUS contribute to protein aggregation, neurodegeneration, and behavioral defects concerning proteostasis mechanisms and prion-like propagation. Other aspects of ALS (and other neurodegenerative disease) pathology are covered in detail in reviews elsewhere  or mutant SOD1 (hSOD1) tagged with fluorescent proteins to facilitate visualization of protein localization . These studies have shown that expression of disease-associated mutant forms of SOD1  is associated with increased aggregation and behavioral deficits. The formation of aggregates during aging is correlated with defects in the proteostasis network  despite all hSOD1(mutant) lines showing clear aggregate formation  including heat shock factor 1 (HSF1), Hsp110, a DnaJ family member A2 (DNJ-19), an Hsp70 family member (STC-1), E3 ubiquitin ligase components SEL-10 and RBX-1, and proteins involved in SUMOylation [small ubiquitin-like modifiers (SUMOs)] UBC-9 and GEI-17. Several of these hits were validated through genetic crosses  confirmed earlier findings, showing that expression of GFP-tagged hSOD1-G93A is correlated with reduced locomotion and the formation of large aggregates  via Mos1-mediated single copy insertion (MosSCI). Toxic effects were more subtle in MosSCI transgenic lines compared with conventional multi-copy arrays expressing hSOD1 : single-copy insertions of mutant ceSOD1 showed significantly higher hSOD1WT-YFP inclusions compared with ceSOD1WT or the empty vector control. The authors theorize that the hSOD1WT-YFP inclusions were possibly seeded by misfolded mutant C. elegans SOD1 protein in MosSCI models, suggesting a prion-like propagation effect , ALS-associated mutant forms (Q331K and M337V), or the C-terminal 25 kDa fragment  led to severe locomotor defects  receptor DAF-2, which requires HSF1 for pro-longevity effects  and hTDP-43 transgenic lines improved locomotion and reduced hTDP-43-YFP aggregation  in all transgenic lines  lines was able to partially rescue the locomotion defects observed in G290A and M337V transgenic animals  hTDP-43 also showed similar locomotion defects, with some evidence of aggregate formation in the nucleus of C. elegans led to adult-onset, age-dependent paralysis and progressive motor neuron degeneration in hTDP-43(mutant) lines  hTDP-43 to GABAergic motor neurons of C. elegans ortholog of TDP-43 , the authors showed that ceTDP-43 knockout was linked to sensitivity to oxidative and osmotic stress, as well as increased lifespan at moderate (20°C) temperatures. Unlike effects on hTDP-43 transgenic animals, the effects of the IIS pathway on ceTDP-1-mediated stress responses and lifespan are less clear—two distinct DAF-2 insulin receptor mutants have opposing effects, making it more difficult to derive a conclusive mechanistic link. Nonetheless, ceTDP-43 does appear to be required for the stress resistance in DAF-2 mutants as well as age-dependent proteotoxicity . The authors conclude that mutated FUS is likely to be pathogenic through a gain-of-function effect, rather than through titrating WT-FUS from the nucleus. In future work, it would be interesting to assess whether the colocalization of FUS with stress granules can be initiated by stressors other than acute heat stress  in e Olsen, .C. elegans model expressing wild type and S57Δ mutant hFUS in GABAergic motor neurons, hFUS transgenic lines showed adult-onset, age-dependent locomotion deficits  and complex array of behaviors that can be rapidly assessed experimentally, provides a powerful model animal to pursue investigations into the mechanisms of neuronal dysfunction  system , and is a more practical and ethical system than mammalian models to perform large-scale genetic or pharmacological screens . Interestingly, although the hSOD1-G85R line showed the most significant locomotor defect, this did not correlate with a gross reduction in the number of motor neurons in the thoracic ganglia or with the formation of insoluble species in these neurons  in the eyes leads to significant levels of tissue degeneration. This toxicity was completely reverted by the co-expression of EGFP-tagged 12xQ/N. The authors proposed that dTDP-43 may be sequestered in aggregates formed by EGFP-12xQ/N, thereby titrating excess dTDP-43  of TDP-43 in the Drosophila models expressing FLAG-tagged hTDP-43WT, hTDP-43 with a defective NLS  or hTDP-43 with a defective NES . Neuron-specific expression of these transgenes was larval lethal, so an inducible system was used to bypass developmental effects  species, although hTDP-43ΔNES and hTDP-43ΔNLS expression showed more HMW species compared with hTDP-43WT. When probed with an antibody against phospho-TDP-43(S409/410), hTDP-43ΔNES HMW species, but not those of hTDP-43WT or hTDP-43ΔNLS, were strongly labeled by the pTDP-43 antibody. Interestingly, immunostaining did not reveal the presence of inclusions formed by the expression of any of these transgenes, suggesting that toxicity  does not require the formation of inclusions. This study also demonstrated cell-type-specific toxicity resulting from the expression of hTDP-43 transgenes: in adult neurons, both nuclear and cytoplasmic accumulations of TDP-43 result in toxicity, whereas in muscle and glial cells, only the accumulation of cytoplasmic species of TDP-43 was toxic ] as a modulator of hTDP-43 protein levels  in its 3′ UTR  is highly expressed in neurons and functions in synaptic vesicle exo- and endocytosis  or microautophagy functions (Hsc70–43KA). This suggests that hTDP-43 compromises both chaperone and microautophagy activities of Hsc70–4  do not develop an ALS phenotype  of doxycycline-regulatable transgenic mice expressing a human TDP-43Δ NLS in forebrain neurons (under a CAMKIIa promoter). Recipient mice displayed pTDP-43 inclusions within the ipsilateral injection site within 1-month post-injection, with relatively few inclusions observed on the contralateral side. Furthermore, spatiotemporal immunohistochemical analysis of mice injected with TDP-43 seeding material showed a transneuronal-like spreading pattern of TDP-43 pathology in the 1–9 months following injection. Unsurprisingly, a large majority of TDP-43 aggregates were observed within forebrain neuronal cells where the CAMKIIa promoter controls the expression of TDP-43Δ NLS. However, TDP-43 aggregates were also found within the subcortical regions including the nucleus accumbens and caudate-putamen, suggesting regional spreading.Observations from ALS and FTLD post-mortem tissue suggests that TDP-43 also exhibits prion-like propagation and spreading throughout neuroanatomical tracts. Until recently there has been a lack of a et al.  were ablin vivo evidence for the prion-like characteristics of TDP-43, further research is required to identify the specific regions of TDP-43 that are important for seeding. As mentioned previously, full-length TDP-43 and its CTFs have multiple amyloidogenic regions  overexpression mouse models under various promoters. Mitchell et al.  were theFUS mutations are inherited in an autosomal dominant fashion, with FUS-R521C mutations commonly observed in FUS-associated fALS patients. Qiu et al.  developeRecently, Zhang et al.  employedTo distinguish the pathological role of FUS aggregates without the confounding effects on RNA metabolism, Shelkovnikova et al., developed a transgenic mouse expressing a truncated human FUS protein (residues 1–359), which lacked the RNA recognition motif and NLS but still retained an N-terminal QGSY prion-like domain , locomotor deficits measured by rotarod test (140 days vs. 120 days), and mortality , however the mechanism was not described -1-piperazinyl]phenyl]-2-thiophenecarboxamide. In vivo experiments using a SOD1-G93A mouse model showed that the drug was well tolerated, with toxicity estimated to be 75 mg/kg. These mice also showed a significant decrease in SOD1 protein levels, but aggregation was not described  in a randomized double-blind clinical trial in Poland, led to a reduction in ALS severity  and median survival time (212–248 days depending on dose) in SOD1-G37R mice compared to vehicle control . Administration of riluzole in conjunction with CuATSM did not exhibit any additive effect , a continuation of the study ongoing (NCT04313166), and a placebo-controlled study currently recruiting (NCT04082832) at the time of publication.Anti-sense oligonucleotides (ASO) can bind to mRNA and reduce protein expression, representing a potential therapeutic strategy  over 11.5 h in phase I, randomized trial of SOD1 fALS was demonstrated to be well tolerated, however, the therapeutic benefits were not measured   is an important chaperone that prevents protein aggregation  in Huntington’s disease patients (Reilmann et al., Years of intensive study into the disease mechanisms of ALS strongly implicates a pathological role for both declining proteostasis and prion-like propagation. There are intimate links between both of these concepts that explain much of the pathological manifestation of ALS. For example, the observation of proteinaceous inclusions in affected tissues, the apparent spread of pathology through neuroanatomically connected tracts, and the preferential degeneration of motor neurons over other cell types. SOD1 and TDP-43 can misfold and aggregate into conformations that can propagate within and between cells in a prion-like manner, as evidenced by the studies mentioned above ranging from biophysical assays of protein stability to whole-organism studies of aggregate seeding. Indeed, this knowledge of proteostasis dysfunction and protein aggregation has led to the development and examination of multiple therapeutics for ALS. The questions that remain, however, are what the conformation of these spreading strains are, the precise mechanism by which they contribute to pathology, and if targeted therapies can be designed to prevent their formation or spread. Also, a question of significant importance to the field is whether FUS can spread pathology from cell-to-cell in a pathological prion-like manner. This knowledge would unify our understanding of the underlying pathomechanisms in ALS.LM directed the manuscript. All authors wrote and edited the manuscript. NRC and JJY conceptualized the manuscript. All authors contributed to the article and approved the submitted version.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.


The presence of premature termination codons (PTCs) in transcripts is dangerous for the cell as they encode potentially deleterious truncated proteins that can act with dominant-negative or gain-of-function effects. To avoid the synthesis of these shortened polypeptides, several RNA surveillance systems can be activated to decrease the level of PTC-containing mRNAs. Nonsense-mediated mRNA decay (NMD) ensures an accelerated degradation of mRNAs harboring PTCs by using several key NMD factors such as up-frameshift (UPF) proteins. Another pathway called nonsense-associated altered splicing (NAS) upregulates transcripts that have skipped disturbing PTCs by alternative splicing. Thus, these RNA quality control processes eliminate abnormal PTC-containing mRNAs from the cells by using positive and negative responses. In this review, we describe the general mechanisms of NMD and NAS and their respective involvement in the decay of aberrant immunoglobulin and TCR transcripts in lymphocytes. The NMD pathway ensures accelerated degradation of premature termination codon (PTC)-containing mRNAs to avoid the synthesis of truncated proteins with potentially deleterious effects for cells ,2,3. PTCThe central NMD factor in human cells is the up-frameshift protein 1 (UPF1), which is an RNA-dependent ATPase and ATP-dependent RNA helicase ,17,18,19The EJC core is a scaffold platform that loads additional NMD factors including UPF3 in the nucleus and UPF2 in the cytoplasm ,38. Two Saccharomyces cerevisiae, only the UPF factors and a DEAD-box helicase , highly homologous to eIF4AIII, are present ,10694,10n (CPTC) . At the frVκ/+ mice harboring an additional PTC-containing V exon on one IgH allele [Our laboratory recently examined the magnitude of NAS during B-cell development and PC differentiation in vivo using the previously mentioned IgHH allele . This moH allele . On one H allele ,113. On H allele . Thus, tH allele .PTC Igκ alleles . NAS is also involved in the targeting of mRNAs harboring PTCs by the exclusion of offending PTC-containing exons by alternative splicing. Even if to date some features have been characterized in the regulation of PTC-containing Ig mRNA levels, more experiments are still required to determine the molecular mechanisms responsible for NAS activation.Exon skipping events eliminating the V exon can be induced by nonsense codons (NAS) or by using antisense oligonucleotides (ASO). Recent evidence has suggested that ASO-mediated Ig exon skipping can be easily achieved by targeting 5′ or 3′ splice sites on V exon pre-mRNAs . Provide