Exosomes and COVID-19: challenges and opportunities.

Coronavirus disease 2019 or COVID-19, starting from Wuhan, China, in December 2019, is a pandemic situation affecting millions worldwide and has exerted a huge burden on healthcare infrastructure. Therefore, there is an urgent need to understand the molecular mechanisms underlying severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and design novel effective therapeutic strategies for combating this pandemic. In this regard, special attention has been paid to the exosomes. These nanoparticles are extracellular vesicles with critical function in the pathogenesis of several diseases including viral sepsis. Therefore, they may be involved in the pathogenesis of COVID-19 infection and also may be a way for transferring viral components and infecting other neighbor cells. Exosomes also can be considered as a therapeutic strategy for treating COVID-19 patients or used as a carrier for delivering effective therapeutic agents. Therefore, in this review, we discussed the biogenesis and contents of exosomes, their function in viral infection, and their potential as a therapeutic candidate in treating COVID-19.

Ameliorative effects of fisetin in letrozole-induced rat model of polycystic ovary syndrome.

BACKGROUND: The present study was conducted to investigate the therapeutic effects of a potent polyphenol, fisetin, on the letrozole-induced rat model of polycystic ovary syndrome (PCOS). METHODOLOGY: Twenty-four female Wistar rats (42 days old) were divided into four groups: control group (received carboxy methylcellulose (CMC 0.5 %)), PCOS group treated with letrozole (1 mg/kg), fisetin group received same dose of letrozole + fisetin (10 mg/kg), and metformin group received same dose of letrozole + metformin (300 mg/kg). At the end of the experiment, biochemical (glucose, lipid profile) and hormonal (insulin, testosterone, estradiol, and progesterone) parameters were analyzed. Histological examinations of ovaries were also conducted by hematoxylin and eosin (H&E) staining. Real-time polymerase chain reaction (PCR) and western blotting were carried out for cytochrome P450 17A1 (CYP17A1), sirtuin-1 (SIRT1), and 5' AMP-activated protein kinase (AMPK) gene expression in the ovaries. Furthermore, enzymatic activities of antioxidants including catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in the ovaries were analyzed by colorimetric method. RESULTS: Letrozole administration resulted in a remarkable abnormality in biochemical and hormonal parameters. Fisetin normalized levels of glucose, lipid profile, homeostatic model assessment for insulin resistance (HOMA-IR), testosterone, estradiol, and progesterone. Moreover, fisetin increased expression levels of SIRT1 and AMPK, and decreased expression level of CYP17A1 in the ovaries. Additionally, fisetin showed protective effect by enhancing antioxidant activities of CAT, SOD, and GPx depleted secondary to induction of PCOS. Fisetin effects were comparable to metformin, as the standard drug used for treatment of PCOS. CONCLUSION: Our results showed that, fisetin treatment caused significant alleviating effects by restoring PCOS-induced alterations in the key genes involved in energy homeostasis and antioxidant enzymes, suggesting that it may have a key role in combating with PCOS.

Therapeutic potential of quercetin in an animal model of PCOS: Possible involvement of AMPK/SIRT-1 axis.

Polycystic ovary syndrome is a common endocrine disorder worldwide. Recently, quercetin has been extensively investigated as a therapeutic option in patients with PCOS. Therefore, this study aimed to investigate the mechanisms underlying quercetin's positive effects by modulating key components of energy homeostasis and adipose tissue hormones in rats with letrozole-induced PCOS. Eighteen female Wistar rats were divided into three groups including control group (received carboxy methylcellulose (CMC 0.5%)), letrozole-induced PCOS ± quercetin group (received 1 mg/kg letrozole in CMC 0.5%), and letrozole-induced PCOS +/+ quercetin group (received same dose of letrozole + 100 mg/kg quercetin in CMC 0.5%). The estrous cycle, biochemical and hormonal parameters, as well as insulin resistance (IR) were evaluated in all groups. Western blotting was used to assess the expression levels of sirtuin-1 (SIRT-1), 5' AMP-activated protein kinase (AMPK), and adiponectin in target tissues of rats. The expression levels of visfatin and resistin were also evaluated through Real-time polymerase chain reaction (PCR). Treatment with quercetin improved the PCOS related disturbances in estrous cycle, lipid profile, serum levels of testosterone, estradiol and progesterone, and IR. Besides, the expression levels of AMPK and SIRT-1 in ovarian tissue were upregulated in the rats which received quercetin. Quercetin also reversed the PCOS-induced alteration in adipose tissue levels of adiponectin, visfatin, and resistin. Modulation of energy homeostasis through key components involved in this axis, as well as regulation of hormones releasing from adipose tissue may be the main underlying mechanisms for positive effects of quercetin in PCOS.

Polyphenols: Natural compounds with promising potential in treating polycystic ovary syndrome.

Polyphenols are natural compounds used by plants as a defense system against various stresses. In recent years, the importance of these polyhydroxyphenols has extensively increased due to their potent cardioprotection, anti-carcinogenic, anti-oxidant, anti-apoptotic, and anti-inflammatory properties. Therefore, various studies have reported promising results from the studies investigating their efficacy as a therapeutic strategy in various disorders such as human malignancies, cardiovascular diseases, nervous system impairments, diabetes, metabolic syndrome, aging, and inflammation-associated disorders, as well as a polycystic ovarian syndrome (PCOS). Since oxidative stress, hormonal, metabolic, and endocrine disturbances have been shown to play a crucial role in the initiation/progression of PCOS, polyphenols are suggested to be an effective treatment for this disorder. Therefore, this study aimed to discuss the therapeutic potential of multiple polyphenols in PCOS.

Nicotinamide and its metabolite N1-Methylnicotinamide alleviate endocrine and metabolic abnormalities in adipose and ovarian tissues in rat model of Polycystic Ovary Syndrome.

Polycystic Ovary Syndrome (PCOS), as a common endocrine disorder is accompanied by hyperandrogenism, insulin resistance, ovulation problems, and infertility. Various types of off-label drugs like metformin have been used for the management of targeted problems caused by PCOS such as insulin resistance and hyperandrogenism. Nicotinamide (NAM) acts as a substrate of visfatin and Nicotinamide N-Methyltransferase (NNMT) leading to the generation of Nicotinamide Adenine Dinucleotide (NAD) and N1-Methylnicotinamide (MNAM), respectively. MNAM is known as an anti-inflammatory, anti-thrombosis, and anti-diabetic agent. In this study, the effects of NAM and MNAM on metabolic and endocrine abnormalities were evaluated in the adipose and ovarian tissues of a letrozole-induced rat model of PCOS. Our results showed that MNAM and NAM reversed abnormal estrous cycle and reduced the serum testosterone levels and CYP17A1 gene expression. Furthermore, all therapeutic factors improved HOMA-IR after treatment and NAM significantly increased the expression of GLUT4 and decreased the gene expression of visfatin. Also, MNAM diminished the gene expression of visfatin and resistin. It is noteworthy that all the therapeutic factors successfully activated the AMPK. In summary, this study is the first study reported beneficial effects of NAM and MNAM on the treatment of PCOS. Additionally, the alleviative effects of our therapeutic factors may be partially mediated by the AMPK-dependent manner due to the contribution of the AMPK in the expression of CYP17A1, visfatin, resistin, and GLUT4. Although more studies are required to unravel the exact mode of actions of MNAM and NAM in the PCOS, the findings of the current study shed light on an urgent need for discovering novel therapeutic pharmaceuticals regarding the treatment of PCOS.

Exosomal miRNAs in osteoarthritis.

Exosomes, as lipid nanostructure, are secreted by approximately all cell types within the body and actively involved in either short or long distances cell-cell communication in an autocrine and paracrine manner. Recently, exosomes are widely used as a nanocarrier for delivery of various nucleotide- or protein passed molecules including miRNA, and drugs into various cells, as a therapeutic strategy in a broad range of diseases including osteoarthritis. Osteoarthritis is one of the most common debilitating chronic musculoskeletal disorders with a multifaceted condition and an increasing impact on the quality of life. Therefore, this review aims to focus on the current knowledge of the exosomal miRNAs in the osteoarthritis to address their potential therapeutic application.

Melatonin: An important anticancer agent in colorectal cancer.

Colorectal cancer is one of the most common cancers among the elderly, which is also seen in the forms of hereditary syndromes occurring in younger individuals. Numerous studies have been conducted to understand the molecular and cellular pathobiology underlying colorectal cancer. These studies have found that cellular signaling pathways are at the core of colorectal cancer pathology. Because of this, new agents have been proposed as possible candidates to accompany routine therapy regimens. One of these agents is melatonin, a neuro-hormone known best for its essential role in upholding the circadian rhythm and orchestrating the many physiologic changes it accompanies. Melatonin is shown to be able to modulate many signaling pathways involved in many essential cell functions, which if deregulated cause an accelerated pace towards cancer. More so, melatonin is involved in the regulation of immune function, tumor microenvironment, and acts as an antioxidant agent. Many studies have focused on the beneficial effects of melatonin in colorectal cancers, such as induction of apoptosis, increased sensitivity to chemotherapy agents and radiotherapy, limiting cellular proliferation, migration, and invasion. The present review aims to illustrate the known significance of melatonin in colorectal cancer and to address possible clinical use.

S100 protein family and embryo implantation.

It is well known that embryo implantation is a critical process in which embryo should be able to reach and attach to endometrium. Until now, various types of factors are involved in the regulation of this process. S100 proteins are calcium-binding proteins, which have vital roles in embryo implantation and have been considered as possible candidate markers for endometrial receptivity. However, studies regarding mode of actions of these proteins are scarce and more mechanistic insights are needed to clarify exact roles of each one of the S100 protein family. Understanding of function of these proteins in different compartments, stages, and phases of endometrium, could pave the way for conducting studies regarding the therapeutic significance of these proteins in some disorders such as recurrent implantation failure. In this review, we outlined roles and possible underlying mechanisms of S100 protein family in embryo implantation.

Endothelins and their receptors in embryo implantation.

As a critical stage of pregnancy, the implantation of blastocysts into the endometrium is a progressive, excessively regulated local tissue remodeling step involving a complex sequence of genetic and cellular interplay executed within an optimal time frame. For better understanding the causes of infertility and, more importantly, for developing powerful strategies for successful implantations and combating infertility, an increasing number of recent studies have been focused on the identification and study of newly described substances in the reproductive tree. The endothelins (ET), a 21-aminoacidic family of genes, have been reported to be responsible for the contraction of vascular and nonvascular smooth muscles, including the smooth muscles of the uterus. Therefore, this review aims to comprehensively discuss the physiological role of endothelins and signaling through their receptors, as well as their probable involvement in the implantation process.

Exosome-based intercellular communication in female reproductive microenvironments.

Different strategies are applied for cellular cross-talk and organization in multicellular organisms. Exosomes are a homogenous population of biological nanoparticles (30-100 nm), originated from multivesicular bodies. The exosomes (Exos) could regulate and affect both cellular physiology and pathophysiology in various organs, such as the female reproductive tract, by altering gene pathways and/or epigenetic programming. Besides, engineered Exos have the potential to be used as a novel drug and gene delivery tools. Here in this review, we discussed various aspects of exosome-based intercellular communication in female reproductive microenvironments. Furthermore, we addressed the findings and issues related to Exos in reproductive biology to give a better view of the involved molecular mechanisms. Moreover, clinical applications of the Exos and their isolation source/methods have been considered to throw some light on the progression of new biological, diagnostic, and therapeutic approaches in clinical embryology.

Dual role of TGF-ß in early pregnancy: clues from tumor progression.

TGF-ß signaling in the endometrium is active during the implantation period and has a pivotal role in regulating endometrial receptivity and embryo implantation. During embryo implantation, both apoptosis and proliferation of endometrial cells happen at the same time and it seems TGF-ß is the factor that controls both of these processes. As shown in cancer cells, in special conditions this cytokine can have a dual effect and switch the action from apoptosis to proliferation. Owing to the similarity between embryo implantation and cancer development and also unusual pattern of proliferation and remodeling in the uterus, in this review we suggest the existence of such a switching in endometrium during the early pregnancy. Moreover, we address some potential mechanisms that could regulate the switching. A better understanding of the molecular mechanisms regulating TGF-ß action and signaling during the implantation period could pave the way for introducing novel therapeutic strategies in order to solve implantation-associated issues such as repeated implantation failure.

Follicular Fluid Levels of Adrenomedullin 2, Vascular Endothelial Growth Factor and its Soluble Receptors Are Associated with Ovarian Response During ART Cycles.

Introduction Adrenomedullin 2 (ADM2) and vascular endothelial growth factor (VEGF) affect ovarian function, especially angiogenesis and follicular development. The actions of VEGF can be antagonized by its soluble receptors, soluble Fms-like tyrosine kinase-1 (sFlt-1) and soluble VEGF receptor 2 (sVEGFR-2), as they decrease its free form. In the present study, we evaluated the relationship between follicular fluid (FF) levels of AMD2, VEGF and its soluble receptors, and ICSI outcomes. Materials and Methods ICSI cycle outcomes were evaluated and FF levels of VEGF, sFlt-1, sVEGFR-2 and ADM2 were determined using ELISA kits. Results FF levels of ADM2, VEGF, and sVEGFR-2 were significantly higher in non-responders compared to other ovarian response groups (p < 0.05). There were significant correlations between ADM2, VEGF and sVEGFR-2 levels as well as VEGF/sFlt-1 and VEGF/sVEGFR-2 ratios (r = 0.586, 0.482, 0.260, and - 0.366, respectively). Based on the ROC curve, the cutoff value for ADM2 as a non-responder predictor was 348.55 (pg/ml) with a sensitivity of 67.7% and a specificity of 94.6%. Conclusions For the first time we measured FF ADM2 levels to determine the relationship to VEGF and its soluble receptors. We suggest that ADM2 could be a potential predictive marker for non-responders. Although the exact function of ADM2 in ovarian angiogenesis is not yet understood, our study may shed light on the possible role of ADM2 in folliculogenesis and ovulation.

MicroRNA-mediated drug resistance in ovarian cancer.

The development of intrinsic or acquired resistance to chemotherapeutic agents used in the treatment of various human cancers is a major obstacle for the successful abolishment of cancer. The accumulated efforts in the understanding the exact mechanisms of development of multidrug resistance (MDR) have led to the introduction of several unique and common mechanisms. Recent studies demonstrate the regulatory role of small noncoding RNA or miRNA in the several parts of cancer biology. Practically all aspects of cell physiology under normal and disease conditions are reported to be controlled by miRNAs. In this review, we discuss how the miRNA profile is changed upon MDR development and the pivotal regulatory role played by miRNAs in overcoming resistance to chemotherapeutic agents. It is hoped that further studies will support the use of these differentially expressed miRNAs as prognostic and predictive markers, as well as novel therapeutic targets to overcome resistance in ovarian cancer.

The role of sphingosine 1 phosphate in coronary artery disease and ischemia reperfusion injury.

Coronary artery disease (CAD) is a common cause of morbidity and mortality worldwide. Atherosclerotic plaques, as a hallmark of CAD, cause chronic narrowing of coronary arteries over time and could also result in acute myocardial infarction (AMI). The standard treatments for ameliorating AMI are reperfusion strategies, which paradoxically result in ischemic reperfusion (I/R) injury. Sphingosine 1 phosphate (S1P), as a potent lysophospholipid, plays an important role in various organs, including immune and cardiovascular systems. In addition, high-density lipoprotein, as a negative predictor of atherosclerosis and CAD, is a major carrier of S1P in blood circulation. S1P mediates its effects through binding to specific G protein-coupled receptors, and its signaling contributes to a variety of responses, including cardiac inflammation, dysfunction, and I/R injury protection. In this review, we will focus on the role of S1P in CAD and I/R injury as a potential therapeutic target.

Ovarian cancer stem cell: A potential therapeutic target for overcoming multidrug resistance.

The cancer stem cell (CSC) model encompasses an advantageous paradigm that in recent decades provides a better elucidation for many important biological aspects of cancer initiation, progression, metastasis, and, more important, development of multidrug resistance (MDR). Such several other hematological malignancies and solid tumors and the identification and isolation of ovarian cancer stem cells (OV-CSCs) show that ovarian cancer also follows this hierarchical model. Gaining a better insight into CSC-mediated resistance holds promise for improving current ovarian cancer therapies and prolonging the survival of recurrent ovarian cancer patients in the future. Therefore, in this review, we will discuss some important mechanisms by which CSCs can escape chemotherapy, and then review the recent and growing body of evidence that supports the contribution of CSCs to MDR in ovarian cancer.

SIRT3-mediated cardiac remodeling/repair following myocardial infarction.

The recent investigations have extensively focused on the importance of sirtuins, as a highly conserved family of gene products, particularly SIRT3 in various biological and pathological processes. SIRT3, the mitochondrial NAD+-dependent deacetylase has been demonstrated to target a broad range of proteins involved in the oxidative stress, ischemia-reperfusion injury, mitochondrial metabolism homeostasis and cellular death. The critical function of SIRT3 in myocardial infarction (MI), which is one of the complex phenotype of coronary artery disease and a result of interaction between various genetic and environmental factors, as well as in cardiac repair and remodeling post-MI have attracted more attention in the recent years. Therefore, in this review, we will summarize important literature about the involvement of SIRT3 in cardiac remodeling/repair following MI and its potential underlying mechanisms.

Correlation Between Circulating Visfatin and Nitric Oxide Metabolites Levels in Patients With Diabetic Nephropathy.

INTRODUCTION: Diabetic nephropathy is one of the serious complications of diabetes mellitus. Visfatin is an intracellular enzyme with insulin-mimicking effects. It enhances the expression of endothelial nitric oxide (NO) synthase in renal cells. This study aimed to investigate serum levels of visfatin and NO metabolites in patients with diabetic nephropathy. MATERIALS AND METHODS: A total of 80 diabetic patients were enrolled and classified into nephropathic and non-nephropathic patients. Serum visfatin and insulin levels were estimated using an enzyme-linked immunosorbent assay, and NO metabolites were estimated using a colorimetric assay. RESULTS: Serum visfatin and NO metabolites levels were significantly elevated in the patients with diabetic nephropathy. Serum visfatin levels and NO metabolites were significantly higher in the nephropathic patients (P = .003; 95% confidence interval, 2.29 to 10.81; P < .001; 95% confidence interval, 3.14 to 9.46, respectively) as compared to the control group, whereas homeostatic model assessment-insulin resistance was significantly lower (P = .02; 95% confidence interval, -1.51 to -1.01).There was no correlation between body mass index, blood pressure, lipid profile, insulin, and glucose levels and serum visfatin and NO metabolites levels. CONCLUSIONS: The results of this study demonstrated that there were high levels of visfatin and NO metabolites in patients with diabetic nephropathy. In addition, there was a positive correlation between visfatin and NO metabolites levels in nephropathic and non-nephropathic diabetic patients.

N1-methylnicotinamide (MNAM) as a guardian of cardiovascular system.

Atherosclerosis is identified as the formation of atherosclerotic plaques, which could initiate the formation of a blood clot in which its growth to coronary artery can lead to a heart attack. N-methyltransferase (NNMT) is an enzyme that converts the NAM (nicotinamide) to its methylated form, N1-methylnicotinamide (MNAM). Higher levels of MNAM have been reported in cases with coronary artery disease (CAD). Further, MNAM increases endothelial prostacyclin (PGI2) and nitric oxide (NO) and thereby causes vasorelaxation. The vasoprotective, anti-inflammatory and anti-thrombotic roles of MNAM have been well documented; however, the exact underlying mechanisms remain to be clarified. Due to potential role of MNAM in the formation of lipid droplets (LDs), it might exert its function in coordination with lipids, and their targets. In this study, we summarized the roles of MNAM in cardiovascular system and highlighted its possible mode of actions.

Association Between Matrix Metalloproteinase-3 Activity and Glomerular Filtration Rate and Albuminuria Status in Patients With Type 2 Diabetes Mellitus.

INTRODUCTION: Diabetic nephropathy is pictured as matrix accumulation and thickening of glomerular basal membrane. Matrix metalloproteinases (MMPs) are major proteases involved in extracellular matrix degradation. Moreover, plasminogen activator inhibitor-1 (PAI-1) primarily regulates plasmin dependent proteolysis. It plays a role in renal fibrosis causing extracellular matrix accumulation through inhibition of plasmin-dependent extracellular matrix degradation. This study investigated PAI-1 serum level and MMP-3 activity and their correlation with glomerular filtration rate in patients with diabetes mellitus. MATERIALS AND METHODS: In a case-control design, serum PAI-1 concentrations and MMP-3 activity were measured in 80 patients with normoalbuminuria, microalbuminuria, and macroalbuminuria. Receiver operating characteristics curve analysis was used to assess the diagnostic accuracy of MMP-3 activity in discriminating albuminuria. RESULTS: In the patients with microalbuminuria, serum PAI-1 levels were higher compared with macroalbuminuric patients (P < .001). The patients with macroalbuminuria exhibited a significantly lower MMP-3 activity than the patients with microalbuminuria and normoalbuminuria (P < .001). No significant correlation was found between serum MMP-3 activity and serum PAI-1 levels in those with normoalbuminuria, microalbuminuria, and macroalbuminuria. The MMP-3 activity had a strong positive correlation with estimated glomerular filtration (r = 0.853, P < .001). CONCLUSIONS: We found that there was a positive correlation between glomerular filtration rate and MMP-3 activity in diabetic patients. This concludes that MMP-3 may have a role in the pathogenesis of diabetic nephropathy progressions towards macroalbuminuria, and therefore, MMP-3 activity may be used in evaluating albuminuria status.

Serum Levels of Vaspin and Its Correlation with Nitric Oxide in Type 2 Diabetic Patients with Nephropathy.

BACKGROUND: Diabetic Nephropathy (DN), a serious and prevalent complication of diabetes, has been rapidly raising worldwide. Vaspin, as an adipokine with anti-diabetic effects, is predominantly released from visceral adipose tissue. Moreover, vaspin has the stimulatory effect on nitric oxide (NO) bioavailability through the activation of NO synthase. OBJECTIVE: The aim of the present study was to investigate the serum levels of vaspin and their correlation with NO metabolite in diabetic patients with normal renal function and renal insufficiency. METHODS: Volunteers patients with non-nephropathy Type 2 Diabetic Mellitus (T2DM) as control (n=40, age= 56.95±6.11 years) and patients with diabetic nephropathy (DN) (n=40, age=57.85±5.63 years) as case group were enrolled in this study, and serum samples were collected for the measurement of vaspin levels by ELISA technique. Also, serum levels of NO metabolites were calorimetrically assessed. RESULTS: We found that vaspin levels significantly decreased in diabetic patients with nephropathic condition as compared with diabetic patients with normal renal function (p <0.04). In addition, serum levels of NO metabolites were significantly higher in diabetic patients with nephropathy in comparison with non-nephropathic diabetics (p<0.001). When patients with DN were studied, vaspin levels positively correlated with NO metabolites and Homeostasis model assessment of insulin resistance (HOMA-IR) levels. CONCLUSION: This study showed that low serum vaspin levels may be a risk factor for nephropathy in type II diabetic patients and increased levels of NO may be a defensive mechanism in the DN.