The efficacy of radiofrequency ablation in the treatment of pediatric arrhythmia and its effects on serum IL-6 and hs-CRP

MiR-10b-5p Regulates Neuronal Autophagy and Apoptosis Induced by Spinal Cord Injury Through UBR7

This study aimed to explore the effects of miR-10b-5p on autophagy and apoptosis in neuronal cells after spinal cord injury (SCI) and the molecular mechanism. Bioinformatics was used to analyze the differentially expressed miRNAs. The expression of related genes and proteins were detected by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) and Western blot, respectively. Cell proliferation was detected by 5-ethynyl-2'-deoxyuridine (EdU), and apoptosis was detected by flow cytometry or terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay (TUNEL). Coimmunoprecipitation confirmed the interaction between UBR7 and Wnt1 or Beclin1. Autophagy was detected by the dansylcadaverine (MDC). The Basso Beattie Bresnahan (BBB) score was used to evaluate motor function, and hematoxylin-eosin (H&E) and Nissl staining were used to detect spinal cord tissue repair and neuronal changes. The result shows that the expression of miR-10b-5p was downregulated in the SCI models, and transfection of a miR-10b-5p mimic inhibited neuronal cell apoptosis. MiR-10b-5p negatively regulated the expression of UBR7, and the inhibitory effect of the miR-10b-5p mimic on neuronal cell apoptosis was reversed by overexpressing UBR7. In addition, UBR7 can regulate apoptosis by affecting the Wnt/β-catenin pathway by promoting Wnt1 ubiquitination. Treatment with the miR-10b-5p mimic effectively improved motor function, inhibited neuronal cell apoptosis, and promoted spinal cord tissue repair in SCI rats. Overall, miR-10b-5p can alleviate SCI by downregulating UBR7 expression, inhibiting Wnt/β-catenin signaling pathway ubiquitination to reduce neuronal apoptosis, or inhibiting Beclin 1 ubiquitination to promote autophagy.

Extracellular vesicles in heart failure

Physiologically, extracellular vesicles (EVs) have been implicated as crucial mediators of immune response, cell homeostasis, angiogenesis, cell differentiation and growth, and tissue repair. In heart failure (HF) they may act as regulators of cardiac remodeling, microvascular inflammation, micro environmental changes, tissue fibrosis, atherosclerosis, neovascularization of plaques, endothelial dysfunction, thrombosis, and reciprocal heart-remote organ interaction. The chapter summaries the nomenclature, isolation, detection of EVs, their biologic role and function physiologically as well as in the pathogenesis of HF. Current challenges to the utilization of EVs as diagnostic and predictive biomarkers in HF are also discussed.

Neuroprotective effect of the Nrf2/ARE/miRNA145-5p signaling pathway in the early phase of spinal cord injury

AIMS

Spinal cord injury (SCI) is a debilitating neurological condition often associated with chronic neuroinflammation and redox imbalance. Oxidative stress is one of the main hallmark of secondary injury of SCI which is tightly regulated by nuclear factor E2-related factor 2/antioxidant response element (Nrf2/ARE) signaling. In this study, we aimed at investigating the interplay between inflammation-related miRNAs and the Nrf2 pathway in animal model of SCI.

MATERIALS AND METHODS

The expression of selected four validated miRNA-target pairs (miRNA223-3p, miRNA155-5p, miRNA145-5p, and miRNA124-3p) was examined at different time points (6 h, 12 h, 1 day, 3 day and 7 day) after SCI. Further, using GFAP-specific kelch-like ECH-associated protein 1 deletion (Keap1-/-) and whole-body Nrf2-/- knockout mice, we investigated the potential interplay between each miRNA and the Keap1/Nrf2 signaling system.

KEY FINDINGS

The expression of all miRNAs except miRNA155-5p significantly increased 24 h after SCI and decreased after 7 days. Interestingly, Keap1-/- mice only showed significant increase in the miRNA145-5p after 24 h SCI compared to the WT group. In addition, Keap1-/- mice showed significant decrease in CXCL10/12 (CXCL12 increased in Nrf2-/- mice), and TNF-α, and an increase in Mn-SOD and NQO-1 (Mn-SOD and NQO-1 decreased in Nrf2-/- mice) compared to WT mice.

SIGNIFICANCE

Our results suggest that astrocytic hyperactivation of Nrf2 exert neuroprotective effects at least in part through the upregulation of miRNA145-5p, a negative regulator of astrocyte proliferation, and induction of ARE in early phase of SCI. Further studies are needed to investigate the potential interplay between Nrf2 and miRNA145-5p in neuroinflammatory condition.

Effect of C reactive protein on the sodium-calcium exchanger 1 in cardiomyocytes

Numerous previous studies have found that C-reactive protein (CRP) is associated with cardiac arrhythmia and cardiac remodeling. However, the underlying mechanisms of this association remain unclear. Sodium-calcium exchanger 1 (NCX1) serves an important role in the regulation of intracellular calcium concentration, which is closely related with cardiac arrhythmia and cardiac remodeling. The present study aimed to evaluate the effects of CRP on NCX1 and intracellular calcium concentration in cardiomyocytes. Primary neonatal mouse ventricular cardiomyocytes were cultured and treated with varying concentrations of CRP (0, 5, 10, 20 and 40 µg/ml). The cardiomyocytes were also treated with NF-κB-specific inhibitor PTDC and a specific inhibitor of the reverse NCX1 KB-R7943 before their intracellular calcium concentrations were measured. mRNA and protein expression levels of NCX1 were detected by reverse transcription-quantitative PCR and western blotting, respectively and intracellular calcium concentration was evaluated by flow cytometry. CRP treatment significantly increased mRNA and protein expression levels of NCX1 in myocytes (P=0.024), as well as intracellular calcium concentration (P=0.01). These results were significantly attenuated by the NF-κB-specific inhibitor PDTC and a specific inhibitor of the reverse NCX1, KB-R7943. CRP significantly upregulated NCX1 expression and increased intracellular calcium concentration in cardiomyocytes via the NF-κB pathway, suggesting that CRP may serve a pro-arrhythmia role via direct influence on the calcium homeostasis of cardiomyocytes.