Involvement of NLRP3 Inflammasome in SARS-Cov-2-Induced Multiorgan Dysfunction in Patients with COVID-19: A Review of Molecular Mechanisms.

Nucleotide-binding domain and leucine-rich repeat protein- 3 (NLRP3) inflammasome is a critical component of the innate immune system. The inflammasome activation is correlated with the COVID- 19 severity. Furthermore, the underlying conditions are accompanied by hyperactivation of NLRP3 inflammasome and poor outcomes. Herein, we presented the involvement of NLRP3 inflammasome in the pathogenies of SARS-CoV-2-induced multiorgan dysfunction and potential therapeutics. Overexpression of NLRP3 inflammasome components and subsequently increased levels of cytokines following viral infection leads to the cytokine storm and indirectly affects the organ functions. Besides, invading host cells via SARS-CoV-2 further activates the NLRP3 inflammasome and induces pyroptosis in immune cells, resulting in the secretion of higher levels of proinflammatory cytokines into the extracellular matrix. These events continued by induction of fibrosis and organ dysfunction following infection with SARS-CoV-2 in critically ill patients. This condition can be observed in individuals with comorbidities (e.g., diabetes, obesity, etc.) due to a primed state of immunity, which can cause severe disease or death in this population. Therefore, understanding the mechanisms underlying host-SARS-CoV-2 interaction may help to clarify the pathophysiology of SARS-CoV-2- induced multiorgan dysfunction and introduce potential therapeutic strategies.

Disulfiram ameliorates bleomycin induced pulmonary inflammation and fibrosis in rats.

Bleomycin (BL) is a widely used anticancer drug that can cause pulmonary fibrosis due to increased fibroblast proliferation and increased secretion of extracellular matrix. RASSF1A is a tumor suppressor gene that is down-regulated by DNA methylation during fibrosis. Disulfiram (DSF), a noncytosine DNA methyltransferase inhibitor, can revert epigenetic biomarkers and re-express silenced genes. We investigated anti-inflammatory and anti-fibrotic effects of DSF on regulation of epigenetic molecules and histopathology in a rat model of BL induced pulmonary fibrosis. We used six groups of rats: sesame oil (SO) control (Co) group, BL group, BL + SO group and three BL + DSF groups administered 1 mg/kg DSF (BL + DSF), 10 mg/kg DSF (BL + DSF10) or 100 mg/kg DSF (BL + DSF100), respectively. BL was administered intratracheally to induce pulmonary fibrosis. DSF and SO were injected intraperitoneally (i.p.) 2 days before BL administration; these injections were continued for 3 weeks. At the end of the study, lung tissues were removed for molecular and histopathologic studies. Administration of 10 or 100 mg/kg DSF after BL induced pulmonary inflammation and fibrosis, and up-regulated RASSF1A and down-regulated TNF-α and IL-1 ß compared to the BL and BL + SO groups. A RASSF1A unmethylated band was observed using the methylation-specific PCR technique in rats that had been administered 10 and 100 mg/kg DSF, which indicated partial DNA demethylation. Histopathologic evaluation revealed that fibrosis and all inflammatory scores were decreased significantly in the BL + DSF10 and BL + DSF100 groups compared to the BL group. Our findings indicate that DSF modified DNA methylation by up-regulating RASSF1A, which reduced inflammation and fibrosis in BL induced pulmonary inflammation and fibrosis.

An Effective Concentration of 5-Aza-CdR to Induce Cell Death and Apoptosis in Human Pancreatic Cancer Cell Line through Reactivating RASSF1A and Up-Regulation of Bax Genes.

BACKGROUND: Promoter hyper-methylation of tumor suppressor genes is a common event that occurs in cancer. As methylation is a reversible modification, agents capable of reversing an abnormal methylation status should help to combat cancer. 5-Aza-CdR is a DNA methyl-transferase inhibitor. The present study aimed to evaluate the effect of 5-Aza-CdR on the proliferation of human pancreatic cancer cell line (PANC-1) and the expression of RASSF1A and Bax genes. METHODS: PANC-1 cells were cultured and treated with 5 and 10 µM/L of 5-Aza-CdR for 24, 48, 72, and 96 hours and the percentages of cell viability and apoptosis were measured by MTT and flow cytometry. RASSF1A gene promoter methylation was assessed by methyl-specific primer-PCR (MSP-PCR) and the expression of RASSF1A and Bax genes was measured using quantitative real-time PCR (qPCR). All quantitative data are presented as mean±SD (standard deviation). The one-way analysis of variance (ANOVA) with the LSD post hoc test was performed for statistical analysis using the SPSS software package, version 16.0. RESULTS: 3-[4,5-dimethythiaziazol-2yl]-2,5-diphenyl tetrazoliumbr omide (MTT) assay revealed that 5-Aza-CdR significantly inhibit the growth and proliferation of PANC-1. The flow cytometry results showed over 40% and 70% of early and late apoptotic cells after treatment with 5 and 10 µm/L of 5-Aza-CdR, respectively. MSP-PCR data indicated that the treatment of cells with 10 µm/L 5-Aza-CdR resulted in partial demethylation of RASSF1A gene promoter. qPCR results showed significant re-expression of RASSF1A and up-regulation of Bax genes after 96 hours treatment of cells with 10 µm/L 5-Aza-CdR versus control cells (P<0.01). CONCLUSION: The result demonstrated that 5 and 10 µM of 5-Aza-CdR induce cell death and apoptosis by epigenetic reactivation of RASSF1A and up-regulation of Bax genes.

Histological changes of kidney in diabetic nephropathy.

Diabetes mellitus is the most common cause of chronic renal disorders and end-stage kidney disease in developed countries. It is the major cause of dialysis and transplantation. Failure in renal function causes wide disorders in the body. Diabetes results in wide range of alterations in the renal tissue. It is believed that early histological changes in diabetic nephropathy are detectable 2 years after diabetes is diagnosed. The glomerular alterations are the most important lesions in the diabetic nephropathy (DN). The Renal Pathology Society provides a new pathological classification for the detection of histopathology of DN. It divides diabetic nephropathy into four hierarchical glomerular lesions. Alloxan or streptozotocin induced diabetic rat is the one most widely used specie to study DN. Histological changes in the rat DN closely resemble the human disease and the most information of this review was obtained through the study of rat DN. All cell types of the kidney such as mesangial cells, podocytes and tubulointerstitial cells are liable to be affected in the event of DN. Severity of renal lesions is associated to the clinical aspect of renal outcome, but the aim of this article was only to review the histological changes of kidney in diabetes mellitus.

Comparison of the anti-cancer effect of Disulfiram and 5-Aza-CdR on pancreatic cancer cell line PANC-1.

BACKGROUND: Pancreatic cancer has poor prognosis by surgical and chemotherapy when it is diagnosed, so other anti-cancerous assistant therapeutic drugs are suggested e.g. epigenetic reversal of tumor-suppressor genes on promoter hypermethylation. 5-Aza-CdR is a nucleoside analog of DNMTi but it has long-term cytotoxicity effects. This study compares the anticancer effect of 5-Aza-CdR and Disulfiram potencies on PANC-1 cell line and up-regulation of p21. MATERIALS AND METHODS: PANC-1 cell line was cultured in DMEM high glucose and treated by 5-Aza-CdR with 5 and 10 µM concentration for four days and 13 µM DSF (Diulfiram) for 24 hours. MS-PCR and RT-PCR were carried out to detect the methylation pattern and estimate the mRNA expression of RASSF1A and p21 in PANC-1. RESULT: MS-PCR demonstrated partial unmethylation after treatment with 5-Aza-CdR while there was no unmethylated band after DSF treatment. RT-PCR showed significant differences between re-expression of RASSF1A before and after treatment with 10 µM 5-Aza-CdR (P < 0.01) but not after treatment with 13 µM DSF (P > 0.05). The significant correlation was observed between RASSF1A re-expression and p21 up-regulation before and after treatment with 10 µM 5-Aza-CdR (P < 0.01) but not after treatment with 13 µM DSF (P > 0.05), while p21 up-regulation was significantly higher after DSF treatment (P < 0.01). CONCLUSION: Our findings indicated that 5-Aza-CdR induces the re-expression of RASSF1A and p21 up-regulation in PANC-1. DSF showed no epigenetic reversion while it affected p21 up-regulation.

Lack of significance of the BRCA2 promoter methylation status in different genotypes of the MTHFR a1298c polymorphism in ovarian cancer cases in Iran.

OBJECTIVE: Promoter methylation, which can be regulated by MTHFR activity, is associated with silencing of genes. In this study we evaluated the methylation status (type) of the BRCA2 promoter in ovarian cancer patients carrying different genotypes of the MTHFR gene (A or C polymorphisms at position 1298). METHODS: The methylation type of the BRCA2 promoter was evaluated using bisulfate-modified DNA in methylation- specific PCR and the MTHFRa1278c polymorphism was assessed by PCR-RFLP. RESULTS: Analysis of the BRCA2 promoter methylation type of cases showed that 7 out of 60 cases (11.7%) were methylated while the remaining 53 (88.3%) were unmethylated. In methylated cases, one out of the 7 cases had a CC genotype and the remaining 6 methylated cases had an AC genotype. The AA genotype was absent. In unmethylated cases, 34, 18, and one out of these had AC, AA and CC genotype, respectively. CONCLUSION: There was no significant relationship between the methylation types of the BRCA2 promoter in different genotypes of MTHFRa1298c polymorphism in ovarian cancer; p=0.255. There was no significant relation between the methylation types of the BRCA2 promoter in different genotypes of the MTHFRa1298c polymorphism in ovarian cancer.

Sperm DNA damage and its relation with leukocyte DNA damage.

DNA fragmentation in human sperm has been related to endogenous and exogenous factors. Exogenous factors can also affect leukocyte DNA integrity. This study evaluated the relation between sperm DNA damage and leukocyte DNA integrity, as a predictor of exogenous factors. DNA damage in the sperm and leukocytes of 41 individuals undergoing ICSI were measured by Comet assay. In addition, sperm chromatin dispersion (SCD) was carried out on semen samples. A positive correlation was observed between the DNA integrity of sperm with leukocytes. When patients were divided into low and high DNA exposure groups, sperm DNA fragmentation was significantly different between the two groups. Cleavage rate and embryo quality showed significant correlation with leukocyte DNA integrity. The results showed that leukocyte DNA integrity could be used to identify individuals at high risk in order to reduce the extent of DNA damage in patients before ICSI in order to improve the subsequent outcome of this procedure.