Exosomes and miRNAs in disease pathogenesis and opportunities for molecular targeting

Exosomes/extracellular vesicles (EVs) are cell-derived mixed-populations of vesicles released by almost all cells into the intercellular microenvironment, ending up in the circulation. Exosomes contain proteins, RNAs and lipid molecules reflecting the status of the parental cell at the time of release, making them promising candidates for biomarker discovery. The contents of exosomes are protected by a lipid bilayer, leading to better stability of bio-macromolecules. Recent evidence suggests a novel role for exosomes as conveyors of information among cells and across tissues, through horizontal transfer of proteins, lipids, and nucleic acids. Exosomes have been the subject of numerous research in recent years; however, their roles still have to be identified in the pathogenesis of different diseases. MicroRNAs (miRNAs) are small (18-25 nucleotide long) non-coding RNAs which play pivotal roles in the gene expression process and it is estimated that about one third of the human genome is controlled by miRNAs. miRNA regulatory processes have been found to influence many essential biological pathways, such as cellular development, proliferation, apoptosis, and cellular signaling. A great proportion of miRNAs has been reported to be associated with the exosome function of different biofluids. The aim of this research was to elucidate the role of exosomes/EVs as well as miRNAs in the pathogenesis of different diseases, including alcoholic liver disease, hepatitis C, and cancer. This knowledge may lead to the development of novel molecular diagnostic approaches, as well as innovative drug delivery modalities for small RNA-targeted therapy. My research resulted in a) the establishment of new methods and approaches to the study of exosomes/EVs, as well as comparative literature on the efficacy of several isolation and characterization techniques. b) identification of the role of exosomes and miRNA-122 in the cross talk between hepatocytes and immune cells in alcoholic liver disease c) identification of the role of exosomes in HCV pathogenesis, including the potential of molecular therapies based on miRNA and exosome targeting in vitro and in vivo d) understanding the bio-distribution of exosomes and miRNA in an in vivo murine model and f) exploring the utility of miRNA and exosomes in biofluids in cancer biomarker discovery

Rapid detection of pathogenic bacteria in whole blood samples using 23S rRNA PCR assays

Purpose: Bloodstream infections are a general cause of death among hospitalized patients. Rapid diagnosis and timely treatment can reduce mortality. The aim of this investigation was to evaluate the 23S rRNA PCR assays as a rapid detection method for diagnose of sepsis in patients with suspected bacteremia. Methods: A cross-sectional study was conducted at Shahid Beheshti University Hospital in Kashan from November 2017 to December 2018. The blood samples of 265 patients with suspected bacteremia were studied by blood culture and 23S rRNA PCR techniques. The results were analyzed using SPSS version 16 and Chi-square test. Results: Eighty (30.2) blood samples of 265 suspected patients, were identified as positive by PCR assays, whereas 27 (10.2) were identified as positive by the blood culture technique. The statistical analysis showed a significant association between the results of PCR assays and blood culture and factors such as prior antibiotic use and underlying diseases (P <0.05). Also a significant correlation was observed between laboratory and clinical criteria and the results of both PCR assays and blood culture (P < 0.05). Conclusion: The 23S rRNA PCR method is a rapid and sensitive technique specially for diagnosing sepsis among patients in whom bacteremia is difficult to diagnose with culture method including neonates and patients who have taken antibiotics before microbial culture. © 2019 Firoozeh et al. All rights reserved

Magnesium Supplementation and the Effects on Wound Healing and Metabolic Status in Patients with Diabetic Foot Ulcer: a Randomized, Double-Blind, Placebo-Controlled Trial

Hypomagnesemia is associated with the development of neuropathy and abnormal platelet activity, both of which are risk factors for diabetic foot ulcer (DFU). This study was carried out to evaluate the effects of magnesium administration on wound healing and metabolic status in subjects with DFU. This randomized, double-blind, placebo-controlled trial was performed among 70 subjects with grade 3 DFU. Subjects were randomly divided into two groups (35 subjects each group) to receive either 250 mg magnesium oxide supplements or placebo daily for 12 weeks. Pre- and post-intervention wound depth and appearance were scored in accordance with the “Wagner-Meggitt’s” wound assessment tool. Fasting blood samples were taken at baseline and after the 12-week intervention to assess related markers. After the 12-week treatment, compared with the placebo, magnesium supplementation resulted in a significant increase in serum magnesium (+0.3 ± 0.3 vs. −0.1 ± 0.2 mg/dL, P < 0.001) and significant reductions in ulcer length (−1.8 ± 2.0 vs. −0.9 ± 1.1 cm, P = 0.01), width (−1.6 ± 2.0 vs. −0.8 ± 0.9 cm, P = 0.02), and depth (−0.8 ± 0.8 vs. −0.3 ± 0.5 cm, P = 0.003). In addition, significant reductions in fasting plasma glucose (−45.4 ± 82.6 vs. −10.6 ± 53.7 mg/dL, P = 0.04), serum insulin values (−2.4 ± 5.6 vs. +1.5 ± 9.6 μIU/mL, P = 0.04), and HbA1c (−0.7 ± 1.5 vs. −0.1 ± 0.4%, P = 0.03) and a significant rise in the quantitative insulin sensitivity check index (+0.01 ± 0.01 vs. −0.004 ± 0.02, P = 0.01) were seen following supplementation of magnesium compared with the placebo. Additionally, compared with the placebo, taking magnesium resulted in significant decrease in serum high-sensitivity C-reactive protein (hs-CRP) (−19.6 ± 32.5 vs. −4.8 ± 11.2 mg/L, P = 0.01) and significant increase in plasma total antioxidant capacity (TAC) concentrations (+6.4 ± 65.2 vs. −129.9 ± 208.3 mmol/L, P < 0.001). Overall, magnesium supplementation for 12 weeks among subjects with DFU had beneficial effects on parameters of ulcer size, glucose metabolism, serum hs-CRP, and plasma TAC levels

Magnesium Supplementation and the Effects on Wound Healing and Metabolic Status in Patients with Diabetic Foot Ulcer: a Randomized, Double-Blind, Placebo-Controlled Trial

Hypomagnesemia is associated with the development of neuropathy and abnormal platelet activity, both of which are risk factors for diabetic foot ulcer (DFU). This study was carried out to evaluate the effects of magnesium administration on wound healing and metabolic status in subjects with DFU. This randomized, double-blind, placebo-controlled trial was performed among 70 subjects with grade 3 DFU. Subjects were randomly divided into two groups (35 subjects each group) to receive either 250 mg magnesium oxide supplements or placebo daily for 12 weeks. Pre- and post-intervention wound depth and appearance were scored in accordance with the �Wagner-Meggitt�s� wound assessment tool. Fasting blood samples were taken at baseline and after the 12-week intervention to assess related markers. After the 12-week treatment, compared with the placebo, magnesium supplementation resulted in a significant increase in serum magnesium (+0.3 ± 0.3 vs. �0.1 ± 0.2 mg/dL, P < 0.001) and significant reductions in ulcer length (�1.8 ± 2.0 vs. �0.9 ± 1.1 cm, P = 0.01), width (�1.6 ± 2.0 vs. �0.8 ± 0.9 cm, P = 0.02), and depth (�0.8 ± 0.8 vs. �0.3 ± 0.5 cm, P = 0.003). In addition, significant reductions in fasting plasma glucose (�45.4 ± 82.6 vs. �10.6 ± 53.7 mg/dL, P = 0.04), serum insulin values (�2.4 ± 5.6 vs. +1.5 ± 9.6 μIU/mL, P = 0.04), and HbA1c (�0.7 ± 1.5 vs. �0.1 ± 0.4, P = 0.03) and a significant rise in the quantitative insulin sensitivity check index (+0.01 ± 0.01 vs. �0.004 ± 0.02, P = 0.01) were seen following supplementation of magnesium compared with the placebo. Additionally, compared with the placebo, taking magnesium resulted in significant decrease in serum high-sensitivity C-reactive protein (hs-CRP) (�19.6 ± 32.5 vs. �4.8 ± 11.2 mg/L, P = 0.01) and significant increase in plasma total antioxidant capacity (TAC) concentrations (+6.4 ± 65.2 vs. �129.9 ± 208.3 mmol/L, P < 0.001). Overall, magnesium supplementation for 12 weeks among subjects with DFU had beneficial effects on parameters of ulcer size, glucose metabolism, serum hs-CRP, and plasma TAC levels. Clinical trial registration number: http://www.irct.ir: IRCT201612225623N96. © 2017, Springer Science+Business Media New York

Biodistribution and function of extracellular miRNA-155 in mice

Circulating miRNAs can be found in extracellular vesicles (EV) and could be involved in intercellular communication. Here, we report the biodistribution of EV associated miR-155 using miR-155 KO mouse model. Administration of exosomes loaded with synthetic miR-155 mimic into miR-155 KO mice resulted in a rapid accumulation and clearance of miR-155 in the plasma with subsequent distribution in the liver, adipose tissue, lung, muscle and kidney (highest to lowest, respectively). miR-155 expression was detected in isolated hepatocytes and liver mononuclear cells of recipient KO mice suggesting its cellular uptake. In vitro, exosome-mediated restoration of miR-155 in Kupffer cells from miR-155 deficient mice augmented their LPS-induced MCP1 mRNA increase. The systemic delivery of wild type plasma to miR-155 KO mice also resulted in a rapid accumulation of miR-155 in the circulation and distribution to the liver and adipose tissue. In summary, our results demonstrate tissue biodistribution and biologic function of EV-associated miR-155

An Insight into the Sex Differences in COVID-19 Patients: What are the Possible Causes?

Studies have reported a sex bias in case fatalities of COVID-19 patients. Moreover, it is observed that men have a higher risk of developing a severe form of the disease compared to women, highlighting the importance of disaggregated data of male and female COVID-19 patients. On the other hand, other factors (eg, hormonal levels and immune functions) also need to be addressed due to the effects of sex differences on the outcomes of COVID-19 patients. An insight into the underlying causes of sex differences in COVID-19 patients may provide an opportunity for better care of the patients or prevention of the disease. The current study reviews the reports concerning with the sex differences in COVID-19 patients. It is explained how sex can affect angiotensin converting enzyme-2 (ACE2), that is a key component for the pathogenesis of COVID-19, and summarized the gender differences in immune responses and how sex hormones are involved in immune processes. Furthermore, the available data about the impact of sex hormones on the immune functions of COVID-19 cases are looked into

Games of Incomplete Information and Myopic Equilibria

A new concept of an equilibrium in games is introduced that solves an open question posed by A. Neyman

Improved Characterization of EV Preparations Based on Protein to Lipid Ratio and Lipid Properties.

In recent years the study of extracellular vesicles has gathered much scientific and clinical interest. As the field is expanding, it is becoming clear that better methods for characterization and quantification of extracellular vesicles as well as better standards to compare studies are warranted. The goal of the present work was to find improved parameters to characterize extracellular vesicle preparations. Here we introduce a simple 96 well plate-based total lipid assay for determination of lipid content and protein to lipid ratios of extracellular vesicle preparations from various myeloid and lymphoid cell lines as well as blood plasma. These preparations included apoptotic bodies, microvesicles/microparticles, and exosomes isolated by size-based fractionation. We also investigated lipid bilayer order of extracellular vesicle subpopulations using Di-4-ANEPPDHQ lipid probe, and lipid composition using affinity reagents to clustered cholesterol (monoclonal anti-cholesterol antibody) and ganglioside GM1 (cholera toxin subunit B). We have consistently found different protein to lipid ratios characteristic for the investigated extracellular vesicle subpopulations which were substantially altered in the case of vesicular damage or protein contamination. Spectral ratiometric imaging and flow cytometric analysis also revealed marked differences between the various vesicle populations in their lipid order and their clustered membrane cholesterol and GM1 content. Our study introduces for the first time a simple and readily available lipid assay to complement the widely used protein assays in order to better characterize extracellular vesicle preparations. Besides differentiating extracellular vesicle subpopulations, the novel parameters introduced in this work (protein to lipid ratio, lipid bilayer order, and lipid composition), may prove useful for quality control of extracellular vesicle related basic and clinical studies

The status of hepatitis C virus infection among people who inject drugs in the Middle East and North Africa.

BACKGROUND AND AIMS: People who inject drugs (PWID) are a key population at high risk of hepatitis C virus (HCV) infection. The aim of this study was to delineate the epidemiology of HCV in PWID in the Middle East and North Africa (MENA). METHODS: Syntheses of data were conducted on the standardized and systematically assembled databases of the MENA HCV Epidemiology Synthesis Project, 1989-2018. Random-effects meta-analyses and meta-regressions were performed. Meta-regression variables included country, study site, year of data collection and year of publication [to assess trends in HCV antibody prevalence over time], sample size and sampling methodology. Numbers of chronically infected PWID across MENA were estimated. The Shannon Diversity Index was calculated to assess genotype diversity. RESULTS: Based on 118 HCV antibody prevalence measures, the pooled mean prevalence in PWID for all MENA was 49.3% [95% confidence interval (CI) = 44.4-54.1%]. The country-specific pooled mean ranged from 21.7% (95% CI = 4.9-38.6%) in Tunisia to 94.2% (95% CI = 90.8-96.7%) in Libya. An estimated 221 704 PWID were chronically infected, with the largest numbers found in Iran at 68 526 and in Pakistan at 46 554. There was no statistically significant evidence for a decline in HCV antibody prevalence over time. Genotype diversity was moderate (Shannon Diversity Index of 1.01 out of 1.95; 52.1%). The pooled mean percentage for each HCV genotype was highest in genotype 3 (42.7%) and in genotype 1 (35.9%). CONCLUSION: Half of people who inject drugs in the Middle East and North Africa appear to have ever been infected with hepatitis C virus, but there are large variations in antibody prevalence among countries. In addition to > 200 000 chronically infected current people who inject drugs, there is an unknown number of people who no longer inject drugs who may have acquired hepatitis C virus during past injecting drug use. Harm reduction services must be expanded, and innovative strategies need to be employed to ensure accessibility to hepatitis C virus testing and treatment