Deciphering the link between Diabetes mellitus and SARS-CoV-2 infection through differential targeting of microRNAs in the human pancreas

Differential Gene Expression Profiles Involved in the Inflammations Due to COVID-19 and Inflammatory Bowel Diseases and the Investigation of Predictive Biomarkers

Gastrointestinal manifestations in COVID-19 were attributed to 74-86% of the hospitalised patients due to severe or prolonged pathogenesis. Though it is a respiratory disease, the impact it elicits on the gastrointestinal tract and brain are intense. Inflammatory bowel disease including Crohn's disease and ulcerative colitis are idiopathic inflammatory disorders of the gastrointestinal tract. The intrinsic mechanisms involved in gut inflammations due to a respiratory viral disease can be deciphered when the gene expression profiles of COVID-19 and IBD are compared. The current study utilises an integrated bioinformatics approach to unravel them. The publicly available gene expression profiles of colon transcriptomes infected with COVID-19, Crohn's disease and Ulcerative colitis were retrieved, integrated and analysed for the identification of differentially expressed genes. The inter-relational analysis along with gene annotation and pathway enrichment detailed the functional and metabolic pathways of the genes during normal and diseased conditions. The protein-protein interactions deduced from the STRING database and the identified hub genes predicted potential biomarker candidates for COVID-19, Crohn's disease and ulcerative colitis. The inflammatory response pathways were upregulated and enrichment of chemokine signalling, altered lipid metabolism, coagulation and complement cascades were seen in all three conditions along with impaired transport mechanisms. CXCL11, MMP10, and CFB are predicted to be overexpressed biomarkers, whilst GUCA2A, SLC13A2, CEACAM, and IGSF9 as downregulated novel biomarker candidates for colon inflammations. The three miRNAs hsa-miR-16-5p, hsa-miR-21-5p, and hsa-miR-27b-5p exhibited significant interactions with the upregulated hub genes and four long non-coding RNAs NEAT1, KCNQ1OT1, and LINC00852 capable of regulating miRNA were also predicted. This study offers significant information on the underlying molecular mechanisms of inflammatory bowel disease with identification of potential biomarkers.

MicroRNA-4691-3p inhibits the inflammatory response by targeting STING in human dental pulp cells: A laboratory investigation

AIM

The regulation of human dental pulp inflammation is not fully understood. This study aims to investigate the effect of miR-4691-3p on the cGAS-STING signalling cascade and its downstream cytokines production in human dental pulp cells (HDPCs).

METHODOLOGY

Normal dental pulp tissue and pulp tissue with irreversible pulpitis from third molars were collected. HDPCs were isolated from pulp tissue. The expression of STING mRNA and miR-4691-3p was measured by quantitative real-time PCR. Bioinformatic computation via TargetScanHuman 8.0 and a luciferase reporter assay was used to identify the targets of miR-4691-3p. A miR-4691-3p mimic and inhibitor were used to upregulate or downregulate miR-4691-3p expression in HDPCs. HDPCs were transfected with c-di-AMP, c-di-GMP, cGAMP, interferon stimulatory DNA (ISD) and bacterial genomic DNA. Immunoblot was performed to detect the phosphorylation of TBK1, p65 and IRF3. Enzyme-linked immunoassay was performed to detect the cytokines including IFN-β, TNF or IL-6 downstream of cGAS-STING.

RESULTS

MiR-4691-3p expression was increased in human dental pulp tissue with irreversible pulpitis. Treatment of HDPCs using recombinant human IFN-β, TNF or IL-6 also upregulated miR-4691-3p. The bioinformatic prediction and luciferase reporter assay confirmed that STING was a direct target of miR-4691-3p. The miR-4691-3p mimic suppressed STING expression, the phosphorylation of TBK1, p65 and IRF3, and the IFN-β, TNF or IL-6 production. In contrast, the miR-4691-3p inhibitor enhanced the STING expression, the phosphorylation of TBK1, p65 and IRF3 and the IFN-β, TNF or IL-6 production.

CONCLUSIONS

MiR-4691-3p negatively regulates the cGAS-STING pathway by directly targeting STING. This provides insight to utilize miRNA-dependent regulatory effect to treat endodontic disease as well as STING-dependent systemic inflammatory disease.

Comparison of salivary MicroRNA-6734, microRNA-3123 and microRNA-4483 expression in smoker and nonsmoker patients: a case control study

BACKGROUND

Tobacco is a major risk factor in oral diseases. Considering the important role of expression miRNA molecules in different diseases, the present study aimed to compare the expression of salivary miRNA-6734, miRNA-3123 and miRNA-4483 in smoker and non-smoker peoples.

METHODS

In this case-control study, salivary samples were obtained from 30 smoker's patients and 27 healthy nonsmokers and matched in term of age and sex. RNA was extracted in salivary samples and gene expression was evaluated in all samples. Statistical analysis of data was performed using T and chi-square tests by SPSS (Ver. 16) software at a significant level of less than 0.05.

RESULTS

The results of this study showed that the expression level of miRNA-3123 and miRNA-4483 in smokers group was 2.8 and 3.2, respectively, which was increased compared to non-smokers with expression level of 1 (P<0.01). There was a significant decrease in the expression rate of miRNA-6734 in smokers (0.6%) compared to non-smokers (P<0.05).

CONCLUSIONS

Based on the results of this study, considering the increasing miRNA-4483 and miRNA-3123 level, as well as the reducing miRNA-6734 level in smokers compared to non-smokers, it seems that evaluation of these two miRNAs as indicator for diagnosis and determination of prognosis of oral diseases associated with smoking can be used.

Signaling pathways and intervention for therapy of type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) represents one of the fastest growing epidemic metabolic disorders worldwide and is a strong contributor for a broad range of comorbidities, including vascular, visual, neurological, kidney, and liver diseases. Moreover, recent data suggest a mutual interplay between T2DM and Corona Virus Disease 2019 (COVID-19). T2DM is characterized by insulin resistance (IR) and pancreatic β cell dysfunction. Pioneering discoveries throughout the past few decades have established notable links between signaling pathways and T2DM pathogenesis and therapy. Importantly, a number of signaling pathways substantially control the advancement of core pathological changes in T2DM, including IR and β cell dysfunction, as well as additional pathogenic disturbances. Accordingly, an improved understanding of these signaling pathways sheds light on tractable targets and strategies for developing and repurposing critical therapies to treat T2DM and its complications. In this review, we provide a brief overview of the history of T2DM and signaling pathways, and offer a systematic update on the role and mechanism of key signaling pathways underlying the onset, development, and progression of T2DM. In this content, we also summarize current therapeutic drugs/agents associated with signaling pathways for the treatment of T2DM and its complications, and discuss some implications and directions to the future of this field.

Evaluation of MicroRNA Expression Pattern (miR-28, miR-181a, miR-34a, and miR-31) in Patients with COVID-19 Admitted to ICU and Diabetic COVID-19 Patients

INTRODUCTION

MicroRNAs, or miRNAs, with regulatory performance in inflammatory responses and infection are the prevalent manifestations of severe coronavirus disease (COVID-19). This study aimed to evaluate whether PBMC miRNAs are diagnostic biomarkers to screen the ICU COVID-19 and diabetic COVID-19 subjects.

METHODS

Candidate miRNAs were selected through previous studies, and then the PBMC levels of selected miRNAs (miR-28, miR-31, miR-34a, and miR-181a) were measured via quantitative reverse transcription PCR. The diagnostic value of miRNAs was determined by the receiver operating characteristic (ROC) curve. The bioinformatics analysis was utilized to predict the DEM genes and relevant bio-functions.

RESULTS

The COVID-19 patients admitted to ICU had significantly greater levels of selected miRNAs compared to non-hospitalized COVID-19 and healthy people. Besides, the mean miR-28 and miR-34a expression levels in the diabetic COVID-19 group were significantly upregulated when compared with the non-diabetic COVID-19 group. ROC analyses demonstrated the role of miR-28, miR-34a, and miR-181a as new biomarkers to discriminate the non-hospitalized COVID-19 group from the COVID-19 patients admitted to ICU samples, and also miR-34a can probably act as a useful biomarker for screening diabetic COVID-19 patients. Using bioinformatics analyses, we found the performance of target transcripts in many bioprocesses and diverse metabolic routes such as the regulation of multiple inflammatory parameters.

DISCUSSION

The difference in miRNA expression patterns between the studied groups suggested that miR-28, miR-34a, and miR-181a could be helpful as potent biomarkers for diagnosing and controlling COVID-19.

Shared genetic architecture between type 2 diabetes and COVID-19 severity

PURPOSE

Patients with type 2 diabetes (T2D) have demonstrated a higher risk for developing more severe cases of COVID-19, but the complex genetic mechanism between them is still unknown. The aim of the present study was to untangle this relationship using genetically based approaches.

METHODS

By leveraging large-scale genome-wide association study (GWAS) summary statistics of T2D and COVID-19 severity, linkage disequilibrium score regression and Mendelian randomization (MR) analyses were utilized to quantify the genetic correlations and causal relationships between the two traits. Gene-based association and enrichment analysis were further applied to identify putative functional pathways shared between T2D and COVID-19 severity.

RESULTS

Significant, moderate genetic correlations were detected between T2D and COVID-19 hospitalization (r_g = 0.156, SE = 0.057, p = 0.005) or severe disease (r_g = 0.155, SE = 0.057, p = 0.006). MR analysis did not support evidence for a causal effect of T2D on COVID-19 hospitalization (OR 1.030, 95% CI 0.979, 1.084, p = 0.259) or severe disease (OR 0.999, 95% CI 0.934, 1.069, p = 0.982). Genes having p_gene < 0.05 for both T2D and COVID-19 severe were significantly enriched for biological pathways, such as response to type I interferon, glutathione derivative metabolic process and glutathione derivative biosynthetic process.

CONCLUSIONS

Our findings further confirm the comorbidity of T2D and COVID-19 severity, but a non-causal impact of T2D on severe COVID-19. Shared genetically modulated molecular mechanisms underlying the co-occurrence of the two disorders are crucial for identifying therapeutic targets.

MiRNA-SARS-CoV-2 dialogue and prospective anti-COVID-19 therapies

COVID-19 is a highly transmissible disease caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), affects 226 countries and continents, and has resulted in >6.2 million deaths worldwide. Despite the efforts of all scientific institutions worldwide to identify potential therapeutics, no specific drug has been approved by the FDA to treat the COVID-19 patient. SARS-CoV-2 variants of concerns make the potential of publicly known therapeutics to respond to and detect disease onset highly improbable. The quest for universal therapeutics pointed to the ability of RNA-based molecules to shield and detect the adverse effects of the COVID-19 illness. One such candidate, miRNA (microRNA), works on regulating the differential expression of the target gene post-transcriptionally. The prime focus of this review is to report the critical miRNA molecule and their regular expression in patients with COVID-19 infection and associated comorbidities. Viral and host miRNAs control the etiology of COVID-19 infection throughout the life cycle and host inflammatory response, where host miRNAs are identified as a double-edged showing as a proviral and antiviral response. The review also covered the role of viral miRNAs in mediating host cell signaling expression during disease pathology. Studying molecular interactions between the host and the SARS-CoV-2 virus during COVID-19 pathogenesis offers the chance to use miRNA-based therapeutics to reduce the severity of the illness. By utilizing an appropriate delivery vehicle, these small non-coding RNA could be envisioned as a promising biomarker in designing a practical RNAi-based treatment approach of clinical significance.

Single-Cell Transcriptome Analysis Reveals the Role of Pancreatic Secretome in COVID-19 Associated Multi-organ Dysfunctions

The SARS-CoV-2 infection affects the lungs, heart, kidney, intestine, olfactory epithelia, liver, and pancreas and brings forward multi-organ dysfunctions (MODs). However, mechanistic details of SARS-CoV-2-induced MODs are unclear. Here, we have investigated the role of pancreatic secretory proteins to mechanistically link COVID-19 with MODs using single-cell transcriptome analysis. Secretory proteins were identified using the Human Protein Atlas. Gene ontology, pathway, and disease enrichment analyses were used to highlight the role of upregulated pancreatic secretory proteins (secretome). We show that SARS-CoV-2 infection shifts the expression profile of pancreatic endocrine cells to acinar and ductal cell-specific profiles, resulting in increased expression of acinar and ductal cell-specific genes. Among all the secretory proteins, the upregulated expression of IL1B, AGT, ALB, SPP1, CRP, SERPINA1, C3, TFRC, TNFSF10, and MIF was mainly associated with disease of diverse organs. Extensive literature and experimental evidence are used to validate the association of the upregulated pancreatic secretome with the coagulation cascade, complement activation, renin-angiotensinogen system dysregulation, endothelial cell injury and thrombosis, immune system dysregulation, and fibrosis. Our finding suggests the influence of an upregulated secretome on multi-organ systems such as nervous, cardiovascular, immune, digestive, and urogenital systems. Our study provides evidence that an upregulated pancreatic secretome is a possible cause of SARS-CoV-2-induced MODs. This finding may have a significant impact on the clinical setting regarding the prevention of SARS-CoV-2-induced MODs.