micro-RNAs dependent regulation of DNMT and HIF1α gene expression in thrombotic disorders

Candidate Signature miRNAs from Secreted miRNAome of Human Lung Microvascular Endothelial Cells in Response to Different Oxygen Conditions: A Pilot Study

Oxygen conditions in the lung determine downstream organ functionality by setting the partial pressure of oxygen, regulating the redox homeostasis and by activating mediators in the lung that can be propagated in the blood stream. Examples for such mediators are secreted soluble or vesicle-bound molecules (proteins and nucleic acids) that can be taken up by remote target cells impacting their metabolism and signaling pathways. MicroRNAs (miRNAs) have gained significant interest as intercellular communicators, biomarkers and therapeutic targets in this context. Due to their high stability in the blood stream, they have also been attributed a role as "memory molecules" that are able to modulate gene expression upon repeated (stress) exposures. In this study, we aimed to identify and quantify released miRNAs from lung microvascular endothelial cells in response to different oxygen conditions. We combined next-generation sequencing (NGS) of secreted miRNAs and cellular mRNA sequencing with bioinformatic analyses in order to delineate molecular events on the cellular and extracellular level and their putative interdependence. We show that the identified miRNA networks have the potential to co-mediate some of the molecular events, that have been observed in the context of hypoxia, hyperoxia, intermittent hypoxia and intermittent hypoxia/hyperoxia.

miR-138-5p ameliorates intestinal barrier disruption caused by acute superior mesenteric vein thrombosis injury by inhibiting the NLRP3/HMGB1 axis

Background

Acute superior mesenteric venous thrombosis (ASMVT) decreases junction-associated protein expression and intestinal epithelial cell numbers, leading to intestinal epithelial barrier disruption. Pyroptosis has also recently been found to be one of the important causes of mucosal barrier defects. However, the role and mechanism of pyroptosis in ASMVT are not fully understood.

Methods

Differentially expressed microRNAs (miRNAs) in the intestinal tissues of ASMVT mice were detected by transcriptome sequencing (RNA-Seq). Gene expression levels were determined by RNA extraction and reverse transcription-quantitative PCR (RT-qPCR). Western blot and immunofluorescence staining analysis were used to analyze protein expression. H&E staining was used to observe the intestinal tissue structure. Cell Counting Kit-8 (CCK-8) and fluorescein isothiocyanate/propidine iodide (FITC/PI) were used to detect cell viability and apoptosis, respectively. Dual-luciferase reporter assays prove that miR-138-5p targets NLRP3.

Results

miR-138-5p expression was downregulated in ASMVT-induced intestinal tissues. Inhibition of miR-138-5p promoted NLRP3-related pyroptosis and destroyed tight junctions between IEC-6 cells, ameliorating ASMVT injury. miR-138-5p targeted to downregulate NLRP3. Knockdown of NLRP3 reversed the inhibition of proliferation, apoptosis, and pyroptosis and the decrease in tight junction proteins caused by suppression of miR-138-5p; however, this effect was later inhibited by overexpressing HMGB1. miR-138-5p inhibited pyroptosis, promoted intestinal epithelial tight junctions and alleviated ASMVT injury-induced intestinal barrier disruption via the NLRP3/HMGB1 axis.

The Role of Clonal Hematopoiesis of Indeterminant Potential and DNA (Cytosine-5)-Methyltransferase Dysregulation in Pulmonary Arterial Hypertension and Other Cardiovascular Diseases

DNA methylation is an epigenetic mechanism that regulates gene expression without altering gene sequences in health and disease. DNA methyltransferases (DNMTs) are enzymes responsible for DNA methylation, and their dysregulation is both a pathogenic mechanism of disease and a therapeutic target. DNMTs change gene expression by methylating CpG islands within exonic and intergenic DNA regions, which typically reduces gene transcription. Initially, mutations in the DNMT genes and pathologic DNMT protein expression were found to cause hematologic diseases, like myeloproliferative disease and acute myeloid leukemia, but recently they have been shown to promote cardiovascular diseases, including coronary artery disease and pulmonary hypertension. We reviewed the regulation and functions of DNMTs, with an emphasis on somatic mutations in DNMT3A, a common cause of clonal hematopoiesis of indeterminant potential (CHIP) that may also be involved in the development of pulmonary arterial hypertension (PAH). Accumulation of somatic mutations in DNMT3A and other CHIP genes in hematopoietic cells and cardiovascular tissues creates an inflammatory environment that promotes cardiopulmonary diseases, even in the absence of hematologic disease. This review summarized the current understanding of the roles of DNMTs in maintenance and de novo methylation that contribute to the pathogenesis of cardiovascular diseases, including PAH.

Rivaroxaban vs. warfarin for the treatment and prevention of venous thromboembolism: A meta-analysis

Background

Anticoagulant treatment is used to treat and prevent venous thromboembolism (VTE). However, the relative effectiveness of newer anticoagulants vs. warfarin has not been appraised.

Objective

The aim was to evaluate the safety and efficacy of rivaroxaban for VTE in comparison to warfarin.

Materials and methods

From January 2000 until October 2021, all related studies were collected by EMBASE, the Cochrane Library, PubMed and Web of Scienceand. During the review process, two reviewers independently analyzed the included studies, including quality evaluation, screening and data extraction. We focused on VTE events as our primary outcomes.

Results

In total, 20 trials were retrieved. These studies involved 230,320 patients, of which 74,018 received rivaroxaban and 156,302 received warfarin. Compared with warfarin, the incidence of VTE in rivaroxaban is significantly lower (risk ratio (RR) 0.71, 95% confidence interval (CI) [0.61, 0.84]; P < 0.0001, random effect model), and significantly reduced major [RR: 0.84, 95% CI (0.77, 0.91); P < 0.0001, fixed effect model] and nonmajor [RR: 0.55, 95% CI (0.41, 0.74); P < 0.0001, fixed effect model] bleeding. No significant differences in all-cause mortality between the two groups [RR: 0.68, 95% CI (0.45, 1.02); P = 0.06, fixed effect model].

Conclusion

Rivaroxaban significantly reduced the incidence of VTE compared to warfarin in this meta-analysis. In order to verify these findings, larger sample sizes are required in well-designed studies.

Insight in Hypoxia-Mimetic Agents as Potential Tools for Mesenchymal Stem Cell Priming in Regenerative Medicine

Hypoxia-mimetic agents are new potential tools in MSC priming instead of hypoxia incubators or chambers. Several pharmaceutical/chemical hypoxia-mimetic agents can be used to induce hypoxia in the tissues: deferoxamine (DFO), dimethyloxaloylglycine (DMOG), 2,4-dinitrophenol (DNP), cobalt chloride (CoCl2), and isoflurane (ISO). Hypoxia-mimetic agents can increase cell proliferation, preserve or enhance differentiation potential, increase migration potential, and induce neovascularization in a concentration- and stem cell source-dependent manner. Moreover, hypoxia-mimetic agents may increase HIF-1α, changing the metabolism and enhancing glycolysis like hypoxia. So, there is clear evidence that treatment with hypoxia-mimetic agents is beneficial in regenerative medicine, preserving stem cell capacities. These agents are not studied so wildly as hypoxia but, considering the low cost and ease of use, are believed to find application as pretreatment of many diseases such as ischemic heart disease and myocardial fibrosis and promote cardiac and cartilage regeneration. The knowledge of MSC priming is critical in evaluating safety procedures and use in clinics. In this review, similarities and differences between hypoxia and hypoxia-mimetic agents in terms of their therapeutic efficiency are considered in detail. The advantages, challenges, and future perspectives in MSC priming with hypoxia mimetic agents are also discussed.

Microarray profile analysis identifies ETS1 as potential biomarker regulated by miR-23b and modulates TCF4 in gastric cancer

Background

Gastric cancer (GC), a common malignancy of the human digestive system, represents the second leading cause of cancer-related deaths worldwide. Early detection of GC has a significant impact on clinical outcomes. The aim of this study was to identify potential GC biomarkers.

Methods

In this study, we conducted a multi-step analysis of expression profiles in GC clinical samples downloaded from TCGA database to identify differentially expressed miRNAs (DEMs) and differentially expressed mRNAs (DEGs). Potential prognostic biomarkers from the available DEMs were then established using the Cox regression method. Gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed to investigate the biological role of the predicted target genes of the miRNA biomarkers. Then, the prognostic DEM-mediated regulatory network was constructed based on transcription factor (TF)–miRNA–target interaction. Subsequently, the consensus genes were further determined based on the overlap between DEGs and these target genes of DEMs. Besides, expression profile, co-expression analysis, immunity, and prognostic values of these prognostic genes were also investigated to further explore the roles in the mechanism of GC tumorigenesis.

Results

We got five miRNAs, including miR-23b, miR-100, miR-143, miR-145, and miR-409, which are associated with the overall survival of GC patients. Subsequently, enrichment analysis of the target genes of the miRNA biomarkers shown that the GO biological process terms were mainly enriched in mRNA catabolic process, nuclear chromatin, and RNA binding. In addition, the KEGG pathways were significantly enriched in fatty acid metabolism, extracellular matrix (ECM) receptor interaction, and proteoglycans in cancer pathways. The transcriptional regulatory network consisting of 68 TFs, 4 DEMs, and 58 targets was constructed based on the interaction of TFs, miRNAs, and targets. The downstream gene ETS1 of miR-23b and TCF4 regulated by ETS1 were obtained by the regulatory network construction and co-expression analysis. High expression of ETS1 and TCF4 indicated poor prognosis in GC patients, particularly in the advanced stages. The expression of ETS1 and TCF4 was correlated with CD4⁺ T cells, CD8⁺ T cells, and B cells.

Conclusions

miR-23b, ETS1, and TCF4 were identified as the prognostic biomarkers. ETS1 and TCF4 had potential immune function in GC, which provided a theoretical basis for molecular-targeted combined immunotherapy in the future.

Mechanisms of Immunothrombosis by SARS-CoV-2

SARS-CoV-2 contains certain molecules that are related to the presence of immunothrombosis. Here, we review the pathogen and damage-associated molecular patterns. We also study the imbalance of different molecules participating in immunothrombosis, such as tissue factor, factors of the contact system, histones, and the role of cells, such as endothelial cells, platelets, and neutrophil extracellular traps. Regarding the pathogenetic mechanism, we discuss clinical trials, case-control studies, comparative and translational studies, and observational studies of regulatory or inhibitory molecules, more specifically, extracellular DNA and RNA, histones, sensors for RNA and DNA, as well as heparin and heparinoids. Overall, it appears that a network of cells and molecules identified in this axis is simultaneously but differentially affecting patients at different stages of COVID-19, and this is characterized by endothelial damage, microthrombosis, and inflammation.