Radiation therapy (RT) in the management of pelvic cancers remains a clinical challenge to urologists given the sequelae of urethral stricture disease secondary to fibrosis and vascular insults. The objective of this review is to understand the physiology of radiation-induced stricture disease and to educate urologists in clinical practice regarding future prospective options clinicians have to deal with this condition. The management of post-radiation urethral stricture consists of conservative, endoscopic, and primary reconstructive options. Endoscopic approaches remain an option, but with limited long-term success. Despite concerns with graft take, reconstructive options such as urethroplasties in this population with buccal grafts have shown long-term success rates ranging from 70 to 100%. Robotic reconstruction is augmenting previous options with faster recovery times. Radiation-induced stricture disease is challenging with multiple interventions available, but with successful outcomes demonstrated in various cohorts including urethroplasties with buccal grafts and robotic reconstruction. About 192,000 cases of prostate cancer are diagnosed annually, with patients undergoing treatments such as prostatectomy, external beam radiation therapy (EBRT), and brachytherapy (BT) ,4. PatieRT use in managing pelvic cancer has been shown to lead to multiple sequelae including radiation-induced stricture disease. This has created a complex urologic issue for urologists, notably reconstructive urologists, due to the increased rates of recurrence and complications after treatment of stricture disease, among other sequelae, after the application of ionizing radiation. The CaPSURE (Cancer of the Prostate Strategic Urologic Research Endeavor) database analysis approximates that the likelihood of radiation-induced stricture is around 1.8% for BT and 1.7% for EBRT, while EBRT + BT combination therapy led to an overall likelihood of 5.2% [This review aims to examine the current literature regarding urethral stricture induced by radiation in male patients, explicitly focusing on the effects radiation can have on histology, biochemistry, and biology in tissue, as well as pathogenesis before reviewing the literature regarding the management of radiation-induced urethral strictures.Pelvic RT administered for rectal cancer can impact the bladder and urethra due to the short distance between these organs. Urinary adverse events (AE) are to be expected; however, there is a dearth of studies following potential urologic sequela . StudiesMuise et al. conducted a review of a cohort of 67,527 patients diagnosed with prostate cancer; 72.62% received RT, 24.86% underwent a radical prostatectomy (RP), 4.94% underwent a RP followed by RT, and 0.46% received RT followed by RP. Within five years of completing treatment, 8.44% of those treated with RT developed urethral strictures, compared to the 5.35% diagnosed with strictures after RP [Thirty eight percent of patients with a new diagnosis of PCa choose RT as a treatment modality, and BT and EBRT are the most common options . RadiatiWhen the urethral lumen is subjected to repetitive damage, an atypical narrowing is formed due to these damages causing structural alterations to the supporting spongiosum and connective tissue underlying the urethral lumen ,18. As aImportant distinctions between urethral remodeling and dermal remodeling include differences in the length of the proliferative phase, which peaks at day 5 in dermal remodeling, while in urethral remodeling, students have demonstrated evidence of remodeling on day 10 .Evidence from animal studies suggests strictures result from an increase in collagen and a decrease in smooth muscle content. This leads to compact, fibrotic, and poorly compliant tissue, although it is important to note that these findings have not been established in human studies . Human sp < 0.05) mean total concentration of glycosaminoglycans (GAG) when compared to healthy controls [Stricture formation may also be influenced by modifications in the architecture of the extracellular matrix. Da-Silva et al. analyzed extracellular matrix proteins from the bulbar urethral strictures of 10 patients who were treated with excision and end-to-end anastomosis and compared them to the extracellular matrix proteins present in bulbar urethras from fresh cadavers. The findings revealed that hyaluronic acid was 50% lower and that dermatan sulfate was 68% higher within the extracellular matrix of urethral strictures compared to that of healthy urethras . Strictucontrols .Additionally, these concepts of the mechanisms of stricture formation in the urethra are not uniform across the urethra. The urethra is not homogeneous and the different histologic properties of each section of the urethra change the etiology and mechanism of stricture formation. The navicular fossa, also called the glandular urethra, consists of stratified squamous epithelium and a layer of connective tissue encompassed by corpus spongiosum ,25. The Anterior urethral strictures typically arise due to trauma or infection and exhibit a more prominent spongiofibrosis. Posterior stenosis is commonly caused by iatrogenic injuries, such as RT, with a fibrotic plaque that is rarely circumferential .RT causes unavoidable radiation injury to normal tissues, resulting in acute and late effects on parenchyma, stroma, and vascular structures. Effects that manifest within hours of exposure are characterized as acute changes and can consist of an increase in vascular permeability, lymphocyte adhesion and infiltration, and endothelial cell edema . EffectsFollowing RT, the urothelium exhibits parenchymal and epithelial changes such as cellular atypia, neoplasia, dysplasia, metaplasia, necrosis, and atrophy. One of the most notable and consistent delayed effects of RT is atrophy . DelayedRadiation-induced fibrosis and vascular insufficiency present as delayed effects. The extent of these sequelae is dependent on the surrounding tissues that are impacted and, in the case of blood vessels, is proportional to the size of the vessels impacted. Damage to small capillaries typically results in obliteration, as they are most radiosensitive leading to endothelial swelling and increased permeability, while damage to medium-sized vessels results in fibrinoid necrosis and thrombosis . Damage Radiation-induced endothelial apoptosis plays a prominent role in the series of acute vascular changes. Late-stage radiation changes produce vascular effects involving thickening of the basement membrane, scarring of surrounding tissues alongside the development of telangiectasias, and a decline in clonogenic capacity, which presumably contributes to the late-stage radiation response to typical parenchyma .The behavior of endothelial cells when exposed to radiation has been extensively studied and understood. The macroscopic changes observed in acute radiation toxicity occur when irradiated endothelial cells undergo structural changes and produce a range of growth factors, chemoattractants, and biomarkers .The prior literature has investigated different pathways involved in radiation-induced stricture formation; however, they are predominantly influenced by damage to the membrane and are mediated by ceramide production and acid sphingomyelinases (ASMases). Most studies exploring this pathway utilized single doses of radiation ranging from 10 to 20 Gy ,26. ThusCeramide activates the ceramide-activated protein kinase (CAPK) and the ceramide-activated phosphatase, leading to apoptosis through the activation of the MAPK8 pathway, the mitochondrial pathway, and the death receptor pathway ,31,32. TCaspase 9 functions as an alternative activation pathway of caspases for apoptosis through mitochondrial proteins. This process is initiated by ceramides, as well. BCL-2-associated protein x (BAX) and BCL-2 antagonist of cell death protein (BAD) are proapoptotic proteins that promote apoptosis when CAPK is induced by ceramide . When BACeramide can be released through cell death or TNF receptor activation. This release leads to a direct apoptotic pathway using different adapter protein complexes including the TNFαR-associated death domain and the Fas-associated death domain . The afoWhen cell death or TNF receptor activation occurs, ceramide is released and a direct apoptotic pathway using different adapter protein complexes is initiated, some of them being the Fas-associated death domain and the TNFαR-associated death domain . These dCeramide can also be released from radiation-induced DNA damage since the ceramide synthase can be activated by DNA double-strand breaks. This pathway would need de novo protein synthesis, which would result in slower kinetics over a longer period of time as a proapoptotic mechanism compared to the sudden release of ceramide once ASMase is activated . DNA damThe balance between pro- and anti-apoptotic signaling cascades and radiation dose determines the amount of endothelial cell apoptosis. For example, ionizing radiation does not lead to endothelial apoptosis directly from the mechanisms listed above, but it also activates anti-apoptotic pathways. A study by Tan et al. revealed that the induction of protein kinase B/AKT (PKB/AKT) signaling determines the viability of endothelial cells that have undergone a single dose of radiation (3 Gy) ,43. WhenToulany et al. found that radiation-induced PKB/AKT signaling is a part of cell survival after the application of ionizing radiation through the stimulation of DNA double-stranded break repair through the induction of DNA-PK . DNA-PK Fibrotic tissue changes are the result of the decreased decomposition and increased production of extracellular matrix (ECM) proteins, especially collagen, which can be caused by radiation exposure. The premature terminal differentiation of potentially mitotic progenitor fibroblasts into irreversible postmitotic fibrocytes can be activated by ionizing radiation ,46,47. GCytokines are important in the mechanisms of radiation-induced injury. TGF-β1 is a cytokine responsible for the proliferation and differentiation of fibroblasts into postmitotic fibrocytes, which secrete collagens and other extracellular matrix proteins. TGF-β1 also controls extracellular matrix homeostasis, which is responsible for the increased production and decreased degradation of extracellular collagen molecules ,27,28. TIL-17 is another cytokine that plays an important role in mediating the response of cells to radiation-related damage such as neutrophil recruitment ,50. BessExcessive accumulation of ECM proteins such as collagen is the most commonly observed component of tissue fibrosis after radiation exposure, mainly through increased synthesis and decreased degradation. The reduced degradation of extracellular collagen that is newly synthesized and deposited can be attributed to the gene expression and production of tissue inhibitors of matrix metalloproteinases (MMP), which is mediated by TGF-β1 . AnotherRadiation causes a variety of histologic alterations including vascular modifications, fibrotic changes, cellular depletions, and inflammatory responses, which manifests progressively as the tissue gets further from the site of radiation exposure ; Table 1Gallet et al. used a mouse model to combine the histologic modifications alongside the levels of growth factors and cytokines that stimulated these modifications in an attempt to create a histologic scoring system . There wPelvic organs and tissue, such as the bladder, may develop radiation cystopathy due to the relatively small spaces in which they are confined. A bladder developing radiation cystopathy may show transient erythema in the first 24 h, progressing to edema, necrosis of basal urothelial cells, urothelial desquamation, ulceration, and finally, hyperemia about 3–6 weeks later ,60,61. CThe dynamics of typical cells during and after RT, especially in relation to the manifestation of stricture formation, is patient dependent and, as such, cannot be observed ,68. WhenWhen RT is administered after surgical intervention, there is a chance for a urethral stricture to develop. This probability does decrease as the amount of time between procedures increases . When RTp = 0.01), higher collagen organization (p = 0.0014), increased number of spindle cells (p = 0.005), and decreased tissue vascularity (p = 0.0005), as well as significant differences in the presence of hyalinized fibrosis (p = 0.03), vacuolation (p = 0.0001), and fat entrapment (p = 0.005) when compared to non-irradiated specimens [Radiation-induced strictures most commonly occur in the bulbomembranous region in patients that elect for primary RT and at the vesicourethral anastomosis (VUA) in patients electing for salvage or neoadjuvant RT. Urethral strictures form when the relative loss of normal cells is over a certain toxicity–specific threshold. Hughes et al. compared membranous urethral strictures in patients with and without radiation treatment for prostate cancer. Nineteen patients had radiation for treatment and fifty-one had no radiation exposure; the post-radiation specimens had a significantly higher collagen density  combined with voiding cystourethrogram (VCUG) used if the retrograde scope cannot pass through the stricture. Additional cross-sectional imaging modalities including CT scan and/or MRI may be required to assess associated pathology . Treatment options for post-RT urethral stricture are conservative management (clean intermittent catheterization or chronic catheter placement), endoscopic management , and primary reconstructive options, with joint decision making to be performed between physician and patient based on oncologic and performance status, stricture location/length/number, bladder status, and current level of continence ,79,80.Patients who are not great candidates for surgery or do not want to undergo more invasive procedures can receive some level of relief from conservative management options for stricture disease. Surgery can carry significant side effects such as new onset or exacerbation of urinary incontinence, along with recurrence of stricture, not to mention the risk associated with general anesthesia . ConservAdditionally, it is important to acknowledge that not all urethral strictures in irradiated patients need to proceed with additional surgical intervention and depend on the balance between impacting bladder emptying and urinary incontinence. This is inherently dependent on an accurate functional and quality of life evaluation to select those patients that would benefit from interventions listed below . It is iDilation and DVIU are endoscopic procedures that can be used in initial interventions for stricture disease; however, these measures have limited long-term success in patients with radiation-induced urethral strictures. A study by Merrick et al. revealed that among 29 patients who had undergone endoscopic treatment of their strictures, 31% needed multiple procedures to achieve patency, and 3 of the patients required suprapubic tube placement after developing recurrent strictures . Similarp = 0.032). The authors were unable to identify any discernable variables such as history of radiation, previous procedures, or endoscopic procedures that were indicative of success [It should be noted that the location of the stricture and which endoscopic procedure is performed impact the outcome. Pfalzgraf et al. observed that patients with VUAS had a higher likelihood of experiencing de novo incontinence after transurethral incision of the stenosis compared to after transurethral resection  the significant radiation-induced fibrosis which makes urethral mobilization difficult and (2) radiated fields have poor vascularity resulting in poor wound healing.The success rate of EPA, defined as not requiring additional procedures, for radiation-induced urethral stricture is reported to be 65–95% ,92,93,94De-novo incontinence rates have been documented to reach up to 36% with 13–17% needing eventual artificial urinary sphincter placement ,91,92,96In the past, augmentation techniques were not performed on radiation patients due to concerns regarding the viability of the graft in such hostile environments. Recent studies suggest that augmented urethroplasties using buccal mucosa grafts (BMG), the most versatile grafts currently used in urologic practice, are a viable repair technique for post-radiation strictures and have outcomes similar to non-radiated patients in the short term and medium term . Buccal Blakely et al. documented findings on three patients with membranous urethral strictures who had undergone dorsal onlay BMG urethroplasty after RT. The results showed that all patients were able to maintain patency with no instances of de novo incontinence during the follow up at 8 months . A subseAdditionally, a single-center retrospective cohort review by Vetterlein et al. reported on 47 patients undergoing ventral onlay buccal mucosal urethroplasty (2009–2016) with a median graft length of 5 cm and demonstrated a recurrence rate of 33%. The authors utilized a validated questionnaire (USS-PROM) showing a mean six-item LUTS score of 7.2 and a mean IIEF-EF score of 4.4. Ultimately, the questionnaire demonstrated that 53% of patients experienced daily urinary incontinence and 26% underwent an artificial urinary sphincter placement. However, in regard to satisfaction, 71% of patients were ultimately satisfied with the outcome .Given the lack of direct comparisons in the literature, further comparative data on repair durability, rates of de novo incontinence, and patient-reported outcomes are required to determine the most suitable technique for managing radiation-induced stricture disease. However, based on the existing literature, surgical reconstructive techniques seem to be viable options for treating stricture disease in such a challenging environment.Robotic surgery has grown as a possible alternative to endoscopic management and open surgery in the treatment of radiation-induced urethral strictures. Open surgery for radiation-induced urethral strictures can lead to longer recovery times, additional interventions, and wound complications due to the hampered healing process present in irradiated tissue ,102. A rTraditionally, open perineal surgery was used for the reconstruction of the posterior urethra, but this technique grew to be more challenging after RT since the natural planes of the tissue are eliminated and fibrosis is present ,101. In Recent developments in surgical techniques, such as non-transection, artery sparing EPA, and intra-sphincter bulboprostatic anastomotic techniques may improve outcomes for radiation-induced urethral stricture disease. The use of BMG for post-radiation stenosis is increasingly accepted as the volume of literature confirming the graft’s ability to survive in a radiated field grows. In that vein, future research is focused on understanding the oral environment during healing to replicate that microenvironment and decrease fibrosis and scar formation . In ordePatients in this population can either be managed conservatively or offered formal reconstruction, depending on patient comorbidities and preference. However, direct comparison studies between excision and augmented techniques are still needed to determine if there is a difference in recurrence, erectile function, and incontinence.Radiation can activate certain proteomic and biochemical changes that contribute to the creation of strictures. Future research will be imperative to better understand these changes, specifically regarding the effect of various RT modalities on the bladder neck and urethra. This will help forecast the results of reconstructive surgery alongside developing a greater understanding and measuring of the mechanisms behind the damage to the urethra. Pre-treatment using prime innate DNA repair mechanisms to avoid radiation-induced changes or molecules that can sequester reactive oxygen species (ROS) require further study of the pathophysiology behind the effects of radiation on tissue, although some possible avenues of investigation include pre-treatment with an ROS scavenger, tyrosine kinase inhibitors, and hyperbaric oxygen therapy ,112,113.Urethroplasty has demonstrated itself as an effective method of dealing with radiation-induced urethral stricture, as shown in Sapienza et al., where strictures were removed successfully 80% of the time, showing a similar efficacy to the 85% success rate in tissue that was not irradiated ,120. In Studies included patients that have undergone BT, EBRT, and sometimes combination therapy, analyzing the rate of stricture formation associated with each modality. However, it was not delineated if each modality of RT lead to more recalcitrant strictures. These data would be able to better inform clinicians when counseling their patients regarding RT.Previous studies on robotic techniques in stricture repair have excluded patients with prior RT. The current literature studying robotic stricture repair in radiation patients has smaller sample sizes and will be worth exploring further, given the efficacy of robotic techniques for other urological conditions.Radiation-induced urethral stricture disease is a prevalent complication of prostatic radiation through imbalances of pro- and anti-apoptotic signaling mechanisms. Conservative management options (intermittent catheterization or endoscopic options) have poor durability but are effective options for patients that do not want to have a procedure under general anesthesia. EPA and augmented repairs have similar rates of recurrence, but augmented repairs seem to have lower rates of de novo urinary incontinence. However, head-to-head comparisons are needed to confirm this. Buccal mucosa has been shown to be a hardy tissue that can survive an irradiated tissue environment, and there is a growing body of literature reporting its viability in urethroplasty. However, future studies including randomized control trials and head-to-head comparisons will be required. Being able to address the damage from radiation immediately through pre-treatment can offer a proactive approach to reduce the need for complex procedures. Finally, more research is needed to understand the changes induced by radiation, how they result in stricture formation, and what may be done to reverse these changes.


Our understanding of the pathophysiology of acute coronary syndrome and of the vascular biology of coronary atherosclerosis has made enormous progress with the implementation of intravascular imaging. Intravascular imaging contributes to overcoming the known limitations of coronary angiography and allows for the in vivo discrimination of plaque morphology giving insight into the underlying pathology of the disease process. The possibility of using intracoronary imaging to characterize lesion morphologies and correlate them with clinical presentations may influence the treatment of patients and improve risk stratification, offering the opportunity for tailored management. This review examines the current role of intravascular imaging and describes how intracoronary imaging represents a valuable tool for modern interventional cardiology in order to improve diagnostic accuracy and offer a tailored approach to the treatment of patients with coronary artery disease, especially in the acute setting. Coronary artery disease (CAD) is a leading cause of death worldwide, and acute coronary syndromes (ACS) are among the most frequent manifestations of ischemic heart disease ,2. DespiCoronary angiography has been used as the gold standard to evaluate the presence, location, and severity of coronary artery disease; however, it provides little or no information regarding plaque composition and biological activity. Intravascular ultrasound (IVUS), near-infrared spectroscopy (NIRS)-IVUS, and optical coherence tomography (OCT) are commercially available intracoronary imaging modalities that allow the visualization and measurements of the lumen, vessel and the evaluation of atherosclerotic plaques composition. The pathophysiological approach to ACS as well as the vascular biology of coronary atherosclerosis have made enormous progress with the implementation of intravascular imaging data over the past two decades. Indeed, intravascular imaging allows for the in vivo discrimination of plaque morphology in patients presenting with ACS with potentially important clinical implications. Indeed, in patients with type 1 myocardial infarction, intravascular imaging may detect three common underlying mechanisms of coronary thrombosis: plaque rupture (PR), plaque erosion (PE), or the presence of calcified nodules (CN), and the determination of these mechanisms may provide an advance towards the goal of a tailored therapy of different culprit lesions. Moreover, the extensive in vivo intracoronary imaging investigation supports the true existence of the so-called “vulnerable” plaques.Therefore, this article aims to review the literature on the use of intravascular imaging to improve diagnostic accuracy and to offer a tailored approach to treatment for ACS patients. Moreover, we describe how the detection and quantification of plaque components are key to assessing the risk of plaque vulnerability.Optical coherence tomography (OCT) achieves very high-resolution image details through a light-based, near-infrared spectrum emitted from a single fiber optic wire, rotating at high speed when pulled back into the vessel. OCT is uniquely placed among the available imaging systems due to an exclusive axial and lateral resolution (10 and 70 μm) ,14. A maIVUS utilizes ultrasound delivered to the vessel wall through a rotating catheter, pulled back into the vessel at a much lower speed compared to light-based OCT, also providing a much lower axial resolution (100 μm), IVUS can easily penetrate plaque up to 10 mm, but not calcium that blocks and shadows the ultrasound signal ,17. NIRSIn summary, OCT, with its higher resolution, is more suitable for close-up detail viewing and provides superior insight regarding the presence of vulnerable plaque features compared to IVUS . TherefoTo date, there is no evidence of the superiority of one intravascular imaging technique compared to the other in clinical outcomes, and therefore they should be considered complementary tools. However, as the guidance with intravascular imaging improves the clinical outcomes of patients undergoing percutaneous coronary intervention , interveACS and type 1 myocardial infarction (MI) are caused by thrombosis developing on a culprit coronary atherosclerotic plaque and critical reduction in blood flow. The exposure of the subendothelial structures and the subsequent activation of platelets by contact with collagen are responsible for thrombosis with the formation of an occlusive or sub-occlusive thrombus with patients usually presenting with ST-elevation MI (STEMI) or non-ST-elevation MI (NSTEMI), respectively. Intravascular imaging has sharpened our ability to characterize the culprit lesions of ACS in living patients. There are three common underlying mechanisms of coronary thrombosis clinically manifesting as ACS: plaque rupture (PR), plaque erosion (PE) and calcified nodule (CN).Each of these mechanisms tends to have specific plaque features , and thePR, followed by intracoronary thrombus formation, is recognized as the most common pathophysiological mechanism in ACS. PR usually occurs in inflamed TCFA, which presents a fibrous cap disruption. Disruption of TCFA directly exposes the underlying necrotic core to the blood with its coagulation factors, and the thrombogenic material residing within the plaque promotes thrombosis. PR is characterized by major distortion of the vessel architecture with a positive remodeling, large necrotic core, fibrous cap disruption, intraplaque cavity, large thrombus burden and a small residual lumen area.In the infarct-related/target lesions, PR and intracoronary thrombus are frequently observed, and compared with lesions in patients without MI, fibrous cap thickness is significantly thinner, and the frequency of OCT-derived TCFA is significantly greater . ImportaThis could also explain why, in STEMI, complete revascularization of “stable” plaque is associated with a reduction in CV mortality compared with culprit-lesion-only PCI ,26. IndeThe second most common underlying substrate for ACS is PE. Multiple studies have reported the prevalence of plaque erosion in approximately 20–40% of patients with ACS ,31. PE iWe have limited knowledge of the mechanisms of superficial erosion. However, these OCT-based intact fibrous cap plaques are less likely to be associated with positive remodeling and lipid core and are more frequently present in smokers or females . The preIn NSTEMI, five independent parameters have been associated with plaque erosion: age < 68 years, anterior ischemia, no diabetes mellitus, hemoglobin > 15.0 g/dL and normal renal function. When all these five parameters were present, the probability of plaque erosion increased to 73.1% . PatientIn a recent study enrolling a total of 822 STEMI  patientsFurthermore, in STEMI patients, PE, compared with PR, was associated with higher rates of patent IRA at first angiography  and a loIn addition, the molecular physiology underlying PE seems to have some important features as a higher expression of toll-like receptor 2, neutrophil, myeloperoxidase and hyaluronidase .These studies suggest that PE may have different pathophysiology and distinct clinical characteristics and that “non-traditional” factors such as local flow disturbance and high endothelial shear stress, which may promote a low-level inflammatory activation of the luminal endothelial cells and cell desquamation, could play an important role.Calcified nodules (CNs) are the least common cause of coronary thrombosis and usually occur in a coronary segment with extensive calcification. Its prevalence is about 2–8% of patients with ACS and is generally more prevalent in older men and in patients with tortuous coronary arteries, diabetes mellitus, or chronic renal failure .Thrombosis occurs when nodular calcification breaches the overlying fibrous cap, thus a luminal surface that is disrupted by nodules of dense calcium. On IVUS/OCT, CNs appear as protruding calcific masses with irregular surface and dorsal shadowing and, by definition, have an overlying thrombus. Lesions with CNs are associated with a small thrombus burden and small or no necrotic core.The premise of precision medicine is “personalized” treatment, which means an individualized approach to treatment, taking into account inter-individual variations. Considering the potential different pathobiology of PR, PE and CN, the direct visualization of these different plaque morphologies may provide a glimpse into the vascular biology of the disease, and this characterization might aid in the derivation of tailored treatment strategies.Patients presenting with ACS and candidates for percutaneous coronary intervention are uniformly treated with stenting regardless of the underlying pathology. However, this one-size-fits-all approach might be modulated and personalized in some individuals. Interestingly, patients with ACS presenting with PR as a culprit lesion have a worse prognosis compared with patients with PE, and this should be taken into account in risk stratification and management . MoreovePrati et al.  have chaIn another single-center, single-arm, unblinded prospective study including a total of 252 (55 patients were from the EROSION study ) patientp = 0.024), with the MACE similar in both groups, although the study was underpowered for clinical outcome assessment. The randomized EROSION III trial  enrolledIdentifying the optimal treatment strategy for treating PE remains a current challenge. Even though the development of personalized treatments contrasting the one-size-fits-all kind of approach is advisable and avoiding stent may be an option in selected cases, the limited number of subjects included in dedicated studies does not allow for drawing definite conclusions and limit the applicability in the real world. Moreover, in patients without stenting, the optimal duration of treatment and drug choice remains unclear. Larger randomized clinical trials comparing standardized medical therapy to revascularization could improve our ability to tailor personalized approaches based on plaque morphologies. However, a well-powered trial would require a very large population to show evidence of the superiority of imaging guidance based on plaque morphology.In the meantime, a continuous effort should be placed on mitigating risk factors and evaluating atherosclerotic burden, which remains an important metric of risk stratification of patients. Indeed, a change in coronary artery plaque characteristics and the increasing incidence of PE rather than PR may derive from better control of cardiovascular risk factors and the increasing use of statin and the subsequent reduction in lipid levels and vascular inflammation . MoreoveA clinically relevant proportion of patients presenting with ACS have non-obstructive coronary artery disease on coronary angiography, and this may pose significant challenges in diagnosis and treatment . ComplemThe concept of high-risk plaques emerged decades ago, opening a new era of research aimed at advancing our knowledge of precursors of adverse cardiac events. Indeed, pathological studies have primarily identified anatomical markers of coronary plaques underlying major cardiac events , some feThe PROSPECT study  showed fWhile NIRS-IVUS made a step forward in detecting vulnerable plaque with large lipid cores, the low resolution of IVUS does not permit for reliably measuring the atheroma plaque cap thickness. The relevance of this feature is paramount; indeed, while lipid-rich plaques are common, they are less likely to be associated with adverse cardiac events in the absence of TCFA .2, fibrous cap thickness <75 μm, lipid arc circumferential extension >180° and presence of macrophages. The concurrent presence of these four OCT criteria in the same plaque was observed in 18.9% of patients experiencing MACE at one year and was independently associated with events.Lipid-rich plaque is defined as TCFA when the thinnest part of the atheroma cap measures ≤65 μm on OCT assessment. However, the exact cut-off value for the fibrous cap or arc of the lipid pool for the identification of an OCT-TCFA is still debated. The recent CLIMA study  identifiThe natural history of OCT-detected TCFA lesions in diabetes mellitus (DM) patients with negative fractional flow reserve (FFR) lesions was assessed in the COMBINE study ,67, whicThese current findings support the true existence of vulnerable plaques and the use of intravascular imaging modalities to detect them and to guide preventive and individualized treatment among patients with CAD. Alternatively, use of a non-invasive imaging tool, such as computer tomography angiography, could be used to search for similar information. We have learned that high-risk plaques are really consistently associated with follow-up clinical events, and this lays the groundwork for powered randomized trials for testing promising systemic and focal treatments, including pharmacotherapy to sequester these plaques or through mechanical plaque pacification with intracoronary devices. The most frequent indication for intravascular imaging is stent-optimization  in orderThe integration of multimodality imaging technologies in a single catheter as a hybrid IVUS-OCT  or OCT-NFuture studies will assess the value of a tailored therapeutic approach of combined OCT-guided focal percutaneous treatment and optimal medical therapy in order to prevent adverse hard cardiac events. The COMBINE INTERVENE (NCT05333068) and PREVENT (NCT02316886) trials will focus on non-ischemic (FFR > 0.75) vulnerable plaques to compare revascularization versus the medical treatment and the INTERCLIMA study (NCT050227984) will compare a functional versus OCT-guided stenting strategy.Intracoronary imaging represents a relevant tool in the management of patients with ACS that clearly contributes to overcoming the known limitations of coronary angiography. It provides detailed information on the atherosclerotic plaque giving insight into the underlying pathology of the disease process and has the potential to guide proper and tailored treatment in an acute setting. Moreover, recent findings support the use of intravascular imaging modalities to detect vulnerable plaque to improve risk stratification and hopefully guide in the next future preventive and individualized treatment. A larger utilization of these modalities, future dedicated randomized studies and continuous technological advances might certainly determine a major shift in the management of patients with CAD.


Editorial on the Research TopicEmerging trends in abdominal and pelvic painAbdominal pain is a cardinal symptom of many disorders of the lower urinary, gastrointestinal and reproductive tracts that requires effective therapeutic management. Pathological changes in one of the pelvic viscera may significantly affect the function/sensation/pain in an adjacent organ, and disrupt normal physiological coordination between the organs . The devZhang et al.; Redwood et al.). Additional research methods, such as magnetic resonance imaging (MRI) for measuring colonic volume and specialized questionnaires for dysmenorrhea catastrophizing, have been implemented. Due to the adverse effects of opioid-based pain management, complementary and integrative methods like electrical neuromodulation have gained more acceptance among doctors and chronic pain patients. Studies of the mechanisms and signaling pathways of neuromodulation using pre-clinical animal models will help further advance the clinical efficacy of neuromodulation. To that end, Zhang et al. aimed to test a new anesthesia protocol for assessing visceral pain in mice and evaluating the effectiveness of invasive neuromodulation. Additionally, a perspective article by Redwood et al. evaluated aged-garlic extract (AGE) as a non-opioid prophylactic treatment for endometrial pain.Dysmenorrhea, a condition characterized by painful menstrual cramps in women, causes a significant decline in productivity and quality of life. Two recent studies have investigated the underlying mechanisms of dysmenorrhea, examining the role of intestinal gas and catastrophizing as potential contributing factors . The study involved 104 women with CPP who completed several questionnaires to assess dysmenorrhea catastrophizing, pain interference, and other related factors. The results revealed a significant association between dysmenorrhea catastrophizing, as well as dysmenorrhea interference and CPP-associated pain interference. The intensity of dysmenorrhea was identified as the most important predictor of catastrophizing. These findings highlight the importance of addressing dysmenorrhea catastrophizing to mitigate the functional impact of the condition, and to improve patients' quality of life. Effective management of dysmenorrhea symptoms to reduce pain intensity is crucial in alleviating interference caused by the condition  . The researchers employed a two-hour window with prolonged urethane infusion followed by surgical procedures under 2% isoflurane anesthesia. The surgical protocol included suturing wire electrodes to the abdominal muscles, placing a polyethylene catheter for urethane infusion, and inserting a plastic-film balloon intra-anally. The mice were then switched to the new urethane anesthesia protocol, involving an initial infusion and continuous low-dose infusion throughout the experiment. The study investigated the correlation between balloon depth on VMR to CRD, and observed depth-dependent responses. Additionally, VMR was assessed in mice with TNBS-induced transient colonic inflammation, revealing a previously unreported sex difference . The optimized anesthesia protocol provided a valuable tool with improved consistency of VMR recordings, allowing objective assessment of various neuromodulatory strategies to alleviate visceral and pelvic pain.Managing visceral pain associated with irritable bowel syndrome (IBS) remains a clinical challenge. Objective biomarkers are crucial for early diagnosis and development of effective treatments. Colorectal distension (CRD) is one of the validated approaches to assess visceral sensitivity. However, measuring visceromotor responses (VMR) in response to CRD in awake rodents is hindered by movement artifacts, thereby, limiting its effectiveness for testing pain management strategies. To overcome these limitations, Zhang et al. tested an optimized anesthesia protocol for reliable VMR recordings during CRD in deeply anesthetized mice , found in garlic, exhibits anti-proliferative effects on endometriomas and downregulates inflammatory pathways. AGE, in particular, contains concentrated immunomodulatory and antioxidant compounds that can benefit endometriosis management. Further research and clinical trials are necessary to validate its effectiveness in managing endometriosis and alleviating CPP.Endometriosis, a debilitating CPP condition with limited treatment options, may benefit from aged-garlic extract (AGE), according to a recent study by In summary, the diagnosis of pelvic pain and respective co-morbidities requires careful investigation of all pelvic organs that could potentially contribute to CCP. Clinical “endo-phenotyping” is a way to identify and group patients based on the trigger points, pain profiles and possible susceptibility to a certain treatment. The development and use of translational animal models, which closely mimic clinical conditions is beneficial to study the mechanisms of pelvic pain, and to identify potential biomarkers for CPP disorders. The latest technological advances including machine learning and artificial intelligence should be tested and incorporated in the development of automatic pain assessments for future use in the pain clinics and clinical research studies . Overall


Perspectives in avian skeletal system and skeletal abnormalities” collected ten original research publications, including topics in bone health in meat birds (four articles), bone health in laying hens (four articles), oxidative stress and bone health (two articles). The compilation provides insights into the impact of nutrition and environmental management on bone health, the relationship between physiological parameters and bone quality, dedicated research into the mechanism of bone remodeling, and the oxidative stresses affecting bone development.The avian skeletal system is gaining increasing attention from researchers as a unique research model for studying bone metabolism, pathologies, and the significance of bone health in relation to animal productivity and welfare. The avian skeleton is a delicate system providing structural support, minerals for eggshell formation, and even acting as an immune organ. Skeletal abnormalities in avian species can have significant implications for poultry farming. Conditions such as osteomyelitis, rickets, and chondrodystrophy, can lead to changes in gait patterns, mobility, and pathophysiologies resulting in detrimental effects on growth performance, health, and economic losses. The current Research Topic entitled “The increased emphasis on genetic selection for meat production has led to birds being required to carry more muscle mass than ever, which poses significant challenges to bone health. Lameness is the most common bone issue, impacting not only birds’ performance but also animal welfare. The common causes of lameness in broilers include femoral head necrosis  and tibial dyschondroplasia (TD).Fan et al., FHN is also linked to dyslipidemia where high lipids levels could increase the blood viscosity, leading to tissue hypoxia, elevated intraosseous pressure, and impaired nutrient transportation. These factors contribute to the development of FHN. Fan et al. investigated the lipid metabolism and bone-related parameters in healthy and spontaneous FHN broilers at 3–5 weeks of age. The results indicated a lipid metabolism disorder in FHN birds, characterized by higher total cholesterol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C) compared to healthy birds. Furthermore, metabolism-related markers provided evidence of increased fat synthesis and decomposition in the FHN group.FHC is associated with microfractures followed by opportunistic bacterial infection. According to the research from Ibelli et al. found differential expression of 34 genes, including downregulation of chondrogenesis and bone differentiation in FHS-affected birds when compared to healthy birds. Moreover, twelve single-nucleotide polymorphisms (SNPs) associated with FHS were identified. This research project provides fundamental information to enhance our understanding of the causes of FHS.Femoral head separation (FHS) is characterized by the detachment of growth plate (GP) and articular cartilage. This condition predisposes the birds to FHN. The causes of FHS are still unclear, but in recent research conducted by Huang et al. revealed a potential non-invasive biomarker, 4-hydroxybenzaldehyde, which can be obtained from fecal samples and used to distinguish TD broilers from normal ones. This potential marker could become a powerful tool for TD diagnosis in the field. In another research project by Lee et al., the researchers explored a different trait affecting bone quality and discovered that Japanese quails with mutated myostatin (MSTN) exhibited higher tibia bone mass and better structural quality. This finding highlights the potential application of MSTN in improving meat yield and bone quality in meat-producing birds.Another common cause of lameness in broilers is tibial dyschondroplasia (TD), characterized by an abnormality in the bone growth plate where excess cartilage template remains without being replaced by bone. The diagnosis of TD typically involves invasive methods, such as exposing the tibial head to observe morphological changes in the growth plate. However, Laying hen bones exhibit unique structures compared to mammalian bones due to the eggshell formation process. Due the need of eggshell formation, unique woven-like medullary bones are developed during sexual maturation to provide a calcium source for eggshell. Genetic selection has led to high egg production, which constantly pressures bone renewal. As the birds age, bone quality issues become significant. Despite numerous papers published in this area, finding an effective solution to reduce this problem remains elusive. Several factors contribute to laying hen bone health, including environmental management, dietary factors, and diseases.Fu et al. demonstrated improvement in eggshell quality and bone quality in aviary systems compared to conventional cages. Notably, the femur showed increased bone resorption activity, possibly related to the enhanced eggshell quality observed. Nevertheless, it is important to note that adopting cage-free production systems can result in increased environmental impacts, a higher incidence of keel bone fractures, and increased gut health challenges. Further research is needed to assess animal welfare in cage-free systems comprehensively, determine the nutrition requirements, and develop strategies to mitigate gut health issues.Regarding management, the transition to cage-free systems is a growing trend driven by animal welfare concerns and consumer preferences. A study conducted by Sinclair-Black et al.). Notably, White et al. conducted an interesting study demonstrating that combining 25-hydroxyvitamin D3 with optimized calcium/phosphorus levels improved pullet bone quality, as evidenced by enhanced cortical and trabecular bone 3D structures. In contrast, the research presented by Xin et al. showed that protein level (15% vs. 16.5%) and energy level  during the prelay period (15–20 weeks) did not impact laying performance. Only slight improvements in egg shape index and eggshell thickness were observed in the high protein treatment group. Molecular parameters indicated that protein and energy levels influenced the expression of HPG axis-related genes of hens towards the end of the laying cycle without altering the circulating sex hormone profile.Nutrition plays an essential role in bone health and laying performance. Extensive research has been conducted to improve laying performance and bone health via nutritional interventions. Previous studies have highlighted the significance of pullet bone quality and its long-term impact on bone health and laying performance during the late laying period .A review by Tompkins et al. has shown that coccidiosis, a protozoal disease, may contribute to bone loss by altering redox balance and impairing antioxidant status induced by coccidia infection caused by Eimeria infection. The authors of this study also mentioned that immune status could be a critical factor in the pathogenesis of bone abnormalities during intestinal parasite infections, warranting further research. This finding highlights that bones are not only structural support for birds but also vital immune organs. In another study conducted by Tompkins et al., mesenchymal stem cells (MSCs) were used as a research model to investigate the effects of oxidative stress on cell fate. The study demonstrated that long-term treatment of chicken MSCs with H2O2 impaired osteogenic differentiation. This research further emphasizes the impact of oxidative stress on bone-related cellular processes.Bone health issues are usually linked to nutritional imbalance, diseases, and management factors. However, research presented by The avian skeletal system is not only a fascinating research model for bone health but also holds great significance in enhancing food production and animal welfare. This Research Topic should inspire future projects to advance our knowledge of avian bone physiology and health. Future research in this field could focus on developing novel tools to evaluate bone quality, uncovering avian osteoimmunology, and exploring the immune functions of bones under various challenges. Furthermore, research is still needed to improve skeletal health through advancements in nutrition, environmental management, breeding strategies, and other relevant areas.


Lung cancer remains the leading cause of cancer-related deaths globally, and the survival rate remains low despite advances in diagnosis and treatment. The progression of lung cancer is a multifaceted and dynamic phenomenon that encompasses interplays among cancerous cells and their microenvironment, which incorporates immune cells. Exosomes, which are small membrane-bound vesicles, are released by numerous cell types in normal and stressful situations to allow communication between cells. Tumor-derived exosomes (TEXs) possess diverse neo-antigens and cargoes such as proteins, RNA, and DNA and have a unique molecular makeup reflecting tumor genetic complexity. TEXs contain both immunosuppressive and immunostimulatory factors and may play a role in immunomodulation by influencing innate and adaptive immune components. Moreover, they transmit signals that contribute to the progression of lung cancer by promoting metastasis, epithelial-mesenchymal transition (EMT), angiogenesis, and immunosuppression. This makes them a valuable resource for investigating the immune environment of tumors, which could pave the way for the development of non-invasive biomarkers that could aid in the prognosis, diagnosis, and immunotherapy of lung cancer. While immune checkpoint inhibitor (ICI) immunotherapy has shown promising results in treating initial-stage cancers, most patients eventually develop adaptive resistance over time. Emerging evidence demonstrates that TEXs could serve as a prognostic biomarker for immunotherapeutic response and have a significant impact on both systemic immune suppression and tumor advancement. Therefore, understanding TEXs and their role in lung cancer tumorigenesis and their response to immunotherapies is an exciting research area and needs further investigation. This review highlights the role of TEXs as key contributors to the advancement of lung cancer and their clinical significance in lung immune-oncology, including their possible use as biomarkers for monitoring disease progression and prognosis, as well as emerging shreds of evidence regarding the possibility of using exosomes as targets to improve lung cancer therapy. Lung cancer continues to be one of the most prevalent forms of malignant tumors, primarily bronchogenic carcinoma and is responsible for a disproportionately high percentage of cancer-related deaths worldwide . Lung caRecent advances in immunotherapy have dramatically altered the treatment perspective for lung cancer, with effectiveness rates far exceeding those of conventional chemotherapy –7. DespiExosomes, first identified in the early 1980s as vesicles that slough off from both normal and cancerous cell lines, belong to the extracellular vesicle (EVs) family , 14. AltExosomes have a crucial function in the TME and can act as a diagnostic and prognostic marker for the alteration of TME and the progression of cancer to a certain degree . Their iExosomes, as major carriers of cell content exchanges, have received much interest for their function in lung cancer –41 and oAlthough the advent of immune checkpoint inhibition therapy has significantly changed the cancer treatment landscape , to fullRecently, exosomes have drawn much attention because of their potential to assist cancer patients with diagnostic and treatment outcomes using liquid biopsy , 65. TheThe current overview starts by describing how TEXs are produced and released into the extracellular matrix of cells and discussing the components that constitute TEXs. The review then delves into how TEXs can modulate the immune system, immunotherapy as a drug delivery vehicle, various immunological checkpoints and the potential for TEXs to serve as diagnostic and prognostic biomarkers for lung cancer, including TEX-derived cancer vaccines.Exosome biogenesis is a well-regulated process influenced by lipid complexes and proteins involved in endocytosis  and initExosome production is a highly regulated process occurring through either of two mechanisms, one dependent on and another independent of the endosomal sorting complex required for transport (ESCRT) , 70. ESCBoth ESCRT-dependent and independent pathways, may differ based on the type of cell and payloads. Moreover, additional signals and pathogenic stimuli the cell is exposed to might also have an impact. Exosomes, upon release, can transfer crucial information to their target cells through a variety of mechanisms. These mechanisms primarily include endocytosis or phagocytosis, and other processes  whereby the exosomes are engulfed by the recipient cells and their contents are subsequently released within the cytoplasm . FurtherThe lipid-protein bilayer membrane of TEXs present in all tumor tissues and bodily fluids contains a variety of proteins, including transport and fusion proteins, adhesion molecules, inhibitory ligands, MHC molecules, tetraspanins, tumor-associated antigens, chaperones, glycolipids , 70, 75.Cancer cells are aberrant cells that develop rapidly and uncontrollably, eventually producing abnormal tissue and tumors. The development and advancement of tumors rely significantly on the characteristics of the surrounding microenvironment, which includes both cellular and non-cellular factors , 76. ExoExosomes that originate from tumor cells are commonly known as TEXs . The nucIn the course of cancer development, cellular crosstalk in the TME and various immune cells is a central driver of tumor progression. When it comes to cancer, the immune system has a double-edged sword effect in encouraging chronic inflammation and stifling antitumor immunity while also killing cancer cells and slowing tumor development. Recent research suggests TEXs play a vital role as important mediators of cellular communication by transmitting both immuno-inhibitory and immune-stimulatory signals to immune cells of TMEs in lung cancer. The effect of immune cell-derived TXEs on the TME in lung cancer is outlined is Table Natural killer (NK) cells are components of innate immune cells capable of acting independently and expressing several receptors with stimulatory or suppressive functions . They caAdditionally, hypoxia also impairs the immune characteristics of NK cells . The redDendritic cells (DCs) are natural immune cells that play an important role in coordinating the immune system's reaction to malignant tumors. These cells are derived from hematopoietic progenitor cells and serve an important part in the natural immunological response . DCs actHuang et al. have demonstrated how exosomes derived from lung cancer biopsies possess heightened levels of epidermal growth factor receptor (EGFR) . These eThe TME contains a heterogenous group of immature myeloid cells known as myeloid-derived suppressor cells (MDSCs), which possess immunosuppressive properties  and whosNevertheless, they promote angiogenesis, invasion, and metastasis while suppressing anti-tumor activity within the tumor microenvironment . It has Additionally, in vivo mice studies have demonstrated that TEXs trigger the accumulation of MDSCs and the heightened secretion of inflammatory mediators, such as IL-6 and vascular endothelial growth factor (VEGF), as well as immunosuppressive agents like nitric oxide and reactive oxygen species, ultimately leading to T cell death . AvailabThe TME plays a pivotal role in the progression and spread of tumors. Macrophages are one of the immunological cells most prevalent in the TME and show distinctive phenotypic alterations in response to varying environmental conditions. These phenotypes can be broadly categorized into two types: M1 macrophages, which are classically activated, and M2 macrophages, which are alternatively activated. M1 macrophages have anti-tumor properties, while M2 macrophages possess anti-inflammatory characteristics and contribute to tumor promotion . Tumor-aIn monocyte survivability and TAM production within the tumor-inflammatory microenvironment, TEXs play a crucial role. Fibrosis, metabolism, cellular debris and T cell activity are directly and indirectly influenced by macrophages by the secretion of pro-inflammatory chemicals . For exaFurthermore, the amount of pro-inflammatory cytokines in lung cancer enhancing carcinogenesis and metastasis can be boosted by TEXs, and the regulation of their release is significantly related to microRNAs . The EV-TEXs have a wide variety of pathways at their disposal to influence T cells. By lowering the stability, proliferation and regulatory activities of these, TEXs are able to change anti-tumor response . They caFurthermore, the adenosine pathway is regulated by TEXs, increasing CD39 expression and adenosine synthesis in Treg . CD73 anPD-L1 immunotherapy is increasingly used in clinical practice to target exosomal PD-L1, which modulates T-cell activity and the immune environment around cancerous tumors . Recent Fibroblasts are normally stimulated to aid in the healing of wounds by producing an extracellular matrix (ECM) that acts as a scaffold for other cells . MyofibrMiRNAs have a significant role in fibroblast differentiation and activation, as shown by the fact that dysregulation of miR-142-3p production causes normal fibroblasts to differentiate into CAFs by altering TGF-signaling . It is aRecently it has been also been demonstrated that a tumor vaccine called fibroblast activation protein-α (FAP) gene-engineered tumor cell-derived exosome-like nanovesicles (eNVs-FAP) can target both tumor parenchyma and the stromal cells (CAFs) which contribute to tumor growth, metastasis, immunosuppression, and drug resistance . It was Epithelial-mesenchymal transition (EMT) is a critical stage and important mechanism in the progression of lung cancer metastasis . In thisAngiogenesis, also known as neovascularization, refers to the process of forming new blood vessels from existing ones in the surrounding tissue. It plays a crucial role in tumor growth and metastasis, as it provides the necessary blood supply to tumors, delivering essential nutrients and oxygen for their survival and growth . Tumors,Additionally, these increase vascular permeability and cancer cell migration by suppressing protein ZO-1 (Zonula occludens 1 protein), a tight junction protein . An incrDespite substantial breakthroughs in detection and therapy, lung cancer control remains a global concern. This is due to a lack of accurate biomarkers leading to ineffective early detection. Biomarkers are indications of a certain physiological or biological state in the body and are critical in medicine for diagnosing normal and abnormal states and assessing therapy response because they can be used to predict the likelihood of progression, recurrence and the efficacy of therapy in cancer settings , 70, 158TEXs and their constituents in bio fluids, carrying the same information as their parent cells, may enable the creation of a distinct molecular profile of a tumor which could aid in the development of non-invasive biomarkers for diagnosis, prognosis and drug resistance, which could be vital in managing patients with lung cancer. Accumulating evidence has demonstrated that analysis of plasma TEXs provide a highly sensitive approach to analyzing lung cancer, and exosomal cargoes that are altered in the tumor can be used as biomarkers for diagnosing, predicting and determining the outcome of lung cancer , 66, 159TEX proteins are emerging and promising cancer biomarkers , 160. ThSeveral studies have researched the possibility of employing a panel of exosomal proteins for identifying lung cancer , 162–166Sandfeld-Paulsen et al. investigated the diagnostic accuracy of a set of membrane-attached exosomal proteins in 336 lung cancer patients and 127 control participants using an array that allows multiplex analysis of several exosomal proteins . They foAnother study identified potential lung cancer biomarkers by profiling extracellular vesicle-derived proteins in healthy individuals and cancer patients using proteomic analysis and differential expression of arrays of proteins . Among tFurthermore, the study also revealed that the expression of exosomal miRNAs, mRNAs, and lncRNAs differed between smokers and NSCLC patients, indicating that smoking might affect the exosome's capacity to regulate molecular components within exosomes and could be a contributing factor to the onset of lung cancer . FurtherExosomal miRNAs are very small non-coding RNA molecules that have been linked to the etiology of lung cancer . Cancer Several investigations have found that exosomal miRNAs play a role in lung cancer progression via a variety of pathways , 169. ExIn a recent study, Jin and colleagues explored the discriminatory ability of TEX biomarkers between squamous cell carcinoma and adenocarcinoma in patients with initial-stage NSCLC by exosomal miRNA profiling in plasma samples . They reNotably, lung cancer patients may also be differently diagnosed by exosomal RNA profiling from pleural effusions. Lin et al. conducted a study to investigate whether analyzing the exosomal profile in pleural effusions could help in the early detection of lung cancer . They anTamiya and colleagues conducted exosomal miRNA profiling in patients with lung adenocarcinoma associated with malignant pleural effusion and reported increased levels of miR-182 and miR-210 . These mStudying the prognostic capacity of miR-21 and miR-4257 in a large cohort of 195 NSCLC patients and 30 healthy controls, Dejima et al.  found thMoreover, Zhang and colleagues  revealedYuwen et al.  investigLong non-coding RNAs (lncRNAs) are a class of RNA molecules that differs from protein-coding mRNAs in that they do not encode proteins, and are transcribed from DNA and can range in length from over 200 nucleotides to more than 100,000 nucleotides, . DespiteOne of the most intensively researched possible biomarkers for detecting NSCLC is metastasis-associated lung adenocarcinoma transcript 1(MALAT1), which accelerates tumor migration and proliferation by suppressing cell apoptosis shortening the cell cycle when highly expressed in NSCLC patient serum . A recenOther potential markers of NSCLC metastasis include six urinary exosomal-derived lncRNAs lnc-, which exhibited significantly higher expression levels in NSCLC patients compared to healthy individuals. Conversely, lnc-ARL6IP6-4, lnc-RP11-80A15.1.1–2, and lnc-DGKQ-1 expression levels were considerably down-regulated in NSCLC patients . Also, eIt has been reported that NSCLC patients exhibit significant upregulation of serum exosomal small nucleolar RNA Host Gene 15 (lncRNA SNHG15) expression compared to individuals with benign lung lesions or without the disease. These upregulated expressions of lncRNA small Nucleolar RNA Host Gene 15 (SNHG15) were identified as an independent predictor of overall survival and closely associated with the differentiation of NSCLC patients across all stages compared to controls . AnotherDespite the encouraging results from the studies on exosomal-derived lncRNAs as possible candidate biomarkers for lung cancer mentioned earlier, the majority of research on lncRNAs is still in the preclinical phase, and there is a lack of understanding about their mechanism of action. Therefore, there is a pressing need for more comprehensive studies on lncRNAs to enable the effective development of cancer diagnosis and treatment strategies.Drug resistance is a significant obstacle that hinders the effectiveness of chemotherapy, radiotherapy, and targeted treatment. Despite a strong initial response to these therapies, most patients with NSCLC acquire drug resistance within 9 to 12 months . As a reIt has been demonstrated that hypoxia worsens drug resistance in lung cancer cells by increasing the expression of pyruvate kinase isozymes M2 (PKM2) in NSCLC. An upregulation had been observed in exosomes released by hypoxic cisplatin-resistant cells. Hypoxic conditions contribute to drug resistance in lung cancer cells through various mechanisms. Firstly, NSCLC cells increase their glycolysis, producing metabolites that counteract the reactive oxygen species triggered by cisplatin. Secondly, hypoxia-induced changes in CAFs create an acidic microenvironment that promotes NSCLC cell proliferation and resistance to cisplatin. These findings shed light on the complex relationship between hypoxia, exosomes, and the development of drug resistance in lung cancer cells .A growing body of evidence indicates that TEXs play a role in drug resistance to EGFR- Tyrosine kinase inhibitors (EGFR-TKIs) through the transfer of exosomal miRNAs , 203. ExTEXs have also been implicated in anaplastic lymphoma kinase (ALK)-TKI resistance, where exosomes from resistant subclones induce resistance in originally sensitive sub-clones through differential expression of miRNAs and lncRNAs. A recent study has shown that exosomes produced by lung cancer cells facilitate the spread of cisplatin resistance to other cancer cells. This resistance was associated with a decrease in the levels of miR-100-5p, which consequently resulted in the downregulation of mTOR expression . In addiMoreover, recent investigations have highlighted the role of lncRNAs and exosome-mediated pathways in fostering lung cancer treatment resistance. Tumor-derived lncRNA H19 has been linked to gefitinib resistance . AccordiTumor-derived exosomes are getting recognition as promising and very efficient delivery systems for drugs used in the therapy of cancer. They are being explored widely as a prospective alternative due to their inherent role in intercellular communication, high biocompatibility, low immunogenicity, ability to remain in the blood circulation for longer periods, biodegradable qualities, and capacity to transverse through various biological barriers , 211. OvA recent study has shown that engineered lung-specific exosomes (231-Exo) loaded with miRNA-126 evaded immune surveillance. They effectively hindered the growth and movement of A549 lung cancer cells via disruption of phosphatase and tensin homolog/phosphatidylinositol 3-kinase/protein kinaseB (PTEN/PI3K/AKT) signaling pathway. Furthermore, in a mouse model with lung metastasis, the miRNA-231-Exo exhibited targeted delivery to the lungs and notably suppressed the formation of lung metastases . SolubleSimilarly, it has been shown that exosomes, coupled with the anti-cancer drug paclitaxel and engineered to incorporate the aminoethylanisamide-polyethylene glycol vector, can specifically target the sigma receptor that is overexpressed in lung cancer cells. This innovative approach led to a substantial accumulation of engineered exosomal complexes within cancer cells after systemic delivery and a better therapeutic outcome .Developing a cancer vaccine represents an innovative and forward-thinking scientific strategy to address global health crises associated with cancer. Exosomes may be used in cancer therapy because they include multivalent surface portions from living cells that are impossible to mimic in artificial nanoparticles . ExosomeExosomes have recently been found to have great promise for cancer immunotherapy, positioning them as a promising tool in developing effective cancer vaccines and an optimal platform for advancing the development of next-generation cancer vaccines . BecauseA relatively untapped field of exosome research is the study of exosomes generated from plants. Exosomes may be able to exhibit anticancer effects and avoid problems from possible post-cancer therapies, according to ongoing research in this area . MoreoveThough the TEX-based exosomal vaccine's initial results appear promising, novel strategies are needed to make TEX-based cancer vaccines a reality. Future therapies might be made possible by engineering TEXs to activate their anti-tumor potential. Understanding the signals inside TEX cargo and connecting them with clinical data is now the biggest challenge in finding and verifying tumor biomarkers. However, implementing TEXs might completely transform how cancer is diagnosed and treated.Immune checkpoints are signaling molecules produced by immunological cells and are thought to be guardians of immune responses . In lungProgrammed death-ligand 1 (PD-L1) is a type I transmembrane protein found primarily on the surface of cancer cells. It can attach to the PD-1 receptor on T cells, inhibiting T cell activation and supporting immunological homeostasis . The intTumor cells have elevated levels of PD-L1 expression which can shield them from immune monitoring by T cells by attaching to PD-1 on activated T cells . When PDClinically, blocking PD-L1 with an antibody activates the anti-tumor immune response, resulting in prolonged remission in certain cancer patients , 249. HoUntil recently, limited research has been conducted on the potential role of PD-L1 expression in TEXs as a biomarker for cancer patients who receive ICIs. Several investigations , 256–258Although recent research has discovered that exo-PD-L1 is associated with lung cancer prognosis, there are still some caveats. First, it is difficult to discern between the pharmacologic effect of the PD-1 inhibitor and the efficacy of autoimmunity during PD-1 therapy. Second, the bulk of studies focus on a retrospective cohort with a relatively small sample size and is therefore prospective; large-scale clinical trials are still necessitated to corroborate these results. Third, a clear methodology for dealing with exo-PD-L1 due to tumor cell heterogeneity is yet to be established.Nevertheless, Exo-PD-L1 is a broader paradigm innovation with promising therapeutic and further research applications. Exo-PD-L1 suppresses immunity, even though the precise mechanism by which it does so is poorly understood. Future research should focus on the assays determining how exo-PD-L1 affects different populations of immune cells , the mechanism behind the impact of induced exo-PD-L1 expression on cancer progression and whether patients develop an autoimmune response to exo-PD-L1. The complexity of the tumor-immune microenvironment implies that more complete models should be utilized in assessing immunotherapy instead of the traditional method of pinpointing genes to identify an appropriate biomarker.The current review highlights TME immunomodulatory properties of exosomes produced from tumor cells. It is clear that, TEXs are important intercellular communication mediators in healthy and pathological conditions. They alter oncogenic pathways in cancer cells and play a significant mechanistic role in the tumor microenvironment, all of which have been shown to promote tumor growth, metastasis, and resistance to treatment of lung cancer.Due to their nonoscale dimensions and capacity for ferrying molecules into certain recipient cells, TEXs have been proposed as potential drug delivery systems, which makes them especially intriguing for biological applications like biomarker molecules and anticancer vaccines.Exosomes can be used as non-invasive biomarkers to complement or supplement standard biopsy since the tumor exosomal payload contains chemicals from the releasing cells and can be found in the blood. Investigating the intricate make-up of exosomes can result in precise, swift medical interventions, screening and detecting initial-stage lung cancer for more favorable prognoses and developing a multianalyte strategy with the potential to offer dynamic insight into the tumor microenvironment.Nevertheless, exosome analysis has yet to be incorporated into clinical recommendations due to numerous hurdles yet to be overcome before exosome-based diagnosis/prognosis and delivery systems can be applied in clinical settings. The primary and most significant obstacle is related to the isolation and comprehensive characterization of exosomes. The lack of uniform procedures for isolating exosomes, appropriate quality controls, and storage methods have hindered the development of medical-grade exosome manufacturing and limited analysis in standard clinical laboratories. Secondly, exosome analysis would benefit from economical and simple-to-use specialized technology. Exosome heterogeneity is intimately associated with the various activities of exosome subgroups with diverse molecular profiles. As a result, single-particle assays which can discriminate between exosome biological origins, size, content and functional influence on recipient cells, could be used to identify exosomes.Furthermore, considerable evidence from in vitro and in vivo animal studies support the involvement of TEX in regulating an immunosuppressive milieu for tumor development. Nevertheless, the relatively short time frame of these and other preclinical investigations may not reflect the dynamic process of cancer cell immunogenicity determined by the phenotype of the encompassing microenvironment and throughout which additional immune evasion mechanisms may evolve. This problem is exacerbated by the paucity of clinical trial research evaluating the therapeutic potential of TEXs in lung cancer and the fact that most studies are retrospective with small cohorts. Consequently, additional prospective studies with larger populations are required to prove TEX use as a liquid biopsy and credible alternative to tumor tissue biopsy.Thereby, the selection of exosome indicators which best correspond with clinical state from among various studies are complicated. Whenever these challenges are resolved, exosomes will most likely play an important role in lung cancer treatment. To do so, further translational research and clinical trials must be conducted before incorporating exosomes into lung cancer treatment.Overall, the available data from preclinical analyses of TEX molecular cargo and their effects on different immune cells support the critical role of TEX in establishing an immunomodulatory microenvironment, which may influence various cancer activities such as invasion, metastasis, EMT and angiogenesis. Notwithstanding the drawbacks and difficulties, a thorough comprehension of the TEXs molecular profile and complex interactions with immune cells in a tumor microenvironment may result in efficient, customized immunotherapy which enhances therapeutic outcomes.Exosome administration of therapeutic drugs is a revolutionary strategy with a bright future in medicine because of the distinct biological properties of exosomes. Medical care for lung cancer should be accurate and individualized, and we propose that TEXs may be altered to improve clinical outcomes and enhance clinical lung cancer care. More research efforts at various levels are required to accomplish this.


Neurorehabilitation is now one of the most exciting areas in neuroscience. Recognition that the central nervous system (CNS) remains plastic through life, new understanding of skilled behaviors (skills), and novel methods for engaging and guiding beneficial plasticity combine to provide unprecedented opportunities for restoring skills impaired by CNS injury or disease. The substrate of a skill is a distributed network of neurons and synapses that changes continually through life to ensure that skill performance remains satisfactory as new skills are acquired, and as growth, aging, and other life events occur. This substrate can extend from cortex to spinal cord. It has recently been given the name “heksor.” In this new context, the primary goal of rehabilitation is to enable damaged heksors to repair themselves so that their skills are once again performed well. Skill-specific practice, the mainstay of standard therapy, often fails to optimally engage the many sites and kinds of plasticity available in the damaged CNS. New noninvasive technology-based interventions can target beneficial plasticity to critical sites in damaged heksors; these interventions may thereby enable much wider beneficial plasticity that enhances skill recovery. Targeted-plasticity interventions include operant conditioning of a spinal reflex or corticospinal motor evoked potential (MEP), paired-pulse facilitation of corticospinal connections, and brain-computer interface (BCI)-based training of electroencephalographic (EEG) sensorimotor rhythms. Initial studies in people with spinal cord injury, stroke, or multiple sclerosis show that these interventions can enhance skill recovery beyond that achieved by skill-specific practice alone. After treatment ends, the repaired heksors maintain the benefits. The research of the past 50 years has shown that the central nervous system (CNS) changes through life. This plasticity is largely activity-dependent; it is driven by interactions between the CNS and its internal and external environments. It is ubiquitous, has many mechanisms, and occurs everywhere from cortex to spinal cord. Neurons change and new neurons may appear, dendrites and axons change, synapses change, glia change, hormonal effects change, even vasculature changes ..11)].unless the rat is exposed to H-reflex up-conditioning  [American Spinal Injury Association Impairment Scale (AIS) C or D ], ThompsThe strategy of inducing targeted plasticity through operant conditioning can be applied to neural pathways other than the soleus H-reflex pathway. For example, operant conditioning of the motor evoked potential (MEP) elicited by transcranial magnetic stimulation (TMS) can target beneficial plasticity to a corticospinal pathway. In people with weak dorsiflexion (foot drop) due to SCI or multiple sclerosis, MEP up-conditioning of the ankle dorsiflexor  increases TA activity during walking, improves ankle joint motion, and improves walking –24.Perez and her research group have used paired corticospinal-motoneuronal stimulation (PCMS) to induce Hebbian plasticity at corticospinal synapses on motoneurons and thereby strengthen cortical control over the motoneurons –29. In aA subsequent study of 31 people with chronic SCI  went on In a controlled study, Pichiorri et al.  studied Norman et al.  reportedAs these first clinical studies show, noninvasive technology-based interventions that target beneficial plasticity to critical sites in damaged heksors are a promising new strategy for enhancing recovery of function. This strategy may be most effective when administered in combination with the mainstay of standard neurorehabilitation, skill-specific practice. The two may be implemented simultaneously  or sequFor example, in Thompson et al.  simply rThis wider plasticity is consistent with the finding that the functional improvements produced by combining targeted plasticity with skill-specific practice persist for at least six months after this combined therapy ends; they do not disappear , 28, 29.The targeted-plasticity strategy has an essential prerequisite: a clear target. Each of the three studies illustrated in In some patients, an appropriate target for plasticity may not be obvious, and the therapist may be concerned that an inappropriate target might possibly have harmful effects. Animal studies provide some reassurance in this regard. In rats with weak stance on one side due to incomplete SCI, soleus H-reflex up-conditioning strengthens the stance burst and restores step symmetry . HoweverIn the meantime, when an appropriate target is not obvious, guidance may be provided by standard measurements of function at the sites that might be targeted. For example, for a person with stroke who has very strong flexor synergies and large H-reflexes in wrist flexors, down-conditioning a flexor H-reflex might be effective . InWith continued development, targeted-plasticity protocols should be applicable to a variety of sites important in sensorimotor function. For example, reciprocal inhibition has been successfully conditioned in rats . Other sSkilled behaviors are produced and maintained by widely distributed networks of neurons and synapses now called heksors. Heksors change continually through life to maintain satisfactory performance of their skills. The primary goal of neurorehabilitation is to enable damaged heksors to repair themselves and regain satisfactory skill performance. Skill-specific practice plus ancillary exercises—the mainstay of standard rehabilitation—does not ensure optimal engagement of the many sites and kinds of plasticity present in the CNS. Thus, heksor plasticity that could improve performance may not occur. Noninvasive technology-based interventions that target beneficial plasticity to critical sites in damaged heksors can improve skill-specific practice and thereby increase the efficacy of standard rehabilitation therapy. The first clinical studies indicate that these new targeted-plasticity interventions can complement standard rehabilitation and enhance recovery of function for people with SCI, stroke, or multiple sclerosis. Most important, the benefits persist after the intervention ends. Just as they adapted as needed to maintain their skills prior to CNS injury, the repaired heksors maintain the beneficial effects initiated by the targeted interventions.