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Abstract Background Several miRNAs including miR-21 have emerged as important regulators in the development of diabetic nephropathy (DN). However, the molecular mechanism of miR-21 underlying DN pathogenesis remains to be further discussed. Methods Streptozotocin (STZ)-induced DN rats and high glucose (HG)-induced podocytes were used as the in vivo and in vitro models of DN. miR-21 level was detected by qRT-PCR assay. Inflammatory cytokine levels were assessed by ELISA. Kidney injury of rats was evaluated by blood glucose, serum creatinine and blood urine nitrogen concentrations and periodic acid schiff (PAS) staining. Apoptosis in kidney tissues and podocytes was determined by TUNEL and flow cytometry analyses, respectively. Western blot analysis was applied to measure the protein levels of tissue inhibitors of metalloproteinase 3 (TIMP3), Bax and Bcl-2. The relationship between TIMP3 and miR-21 was confirmed by luciferase reporter assay. Results miR-21 expression was upregulated in serum and kidney tissues of DN patients, kidney tissues of STZ-induced DN rats, and HG-treated podocytes. miR-21 depletion inhibited pro-inflammatory factor (IL-1β, TNF-α) secretions and alleviated kidney damages in STZ-induced DN rats. Moreover, TIMP3 was a target of miR-21 in HG-treated podocytes. Additionally, TIMP3 overexpression abated HG-induced inflammatory responses and podocyte apoptosis. Furthermore, the inhibitory effects of TIMP3 on inflammatory responses and podocyte apoptosis were alleviated by increased miR-21. Conclusion The down-regulation of miR-21 inhibited the progression of DN by targeting TIMP3 in STZ-induced DN rats and HG-treated podocytes, elucidating a novel regulatory mechanism of miR-21 in DN progression and offering a potential target for DN therapy. [ABSTRACT FROM AUTHOR]

Introduction: Preventing ischemia-reperfusion injury is the main direction of myocardial infarction treatment in the convalescent stage. Some studies have suggested that saponins in Traditional Chinese medicine (TCM) preparations can protect the myocardium by various mechanisms. Our meta-analysis aims to evaluate the efficacy of TCM saponins in treating myocardial ischemia-reperfusion injury (MIRI) and to summarize the potential molecular mechanisms further., Methods: We conducted a literature search in six electronic databases [Web of Science, PubMed, Embase, Cochrane Library, Sinomed, China National Knowledge Infrastructure (CNKI)] until October 2022., Results: Seventeen eligible studies included 386 animals (254 received saponins and 132 received vehicles). The random effect model is used to calculate the combined effect. The effect size is expressed as the weighted average difference (WMD) and 95% confidence interval (CI). Compared with placebo, saponins preconditioning reduced infarct size after MIRI significantly (WMD: -3.60,95% CI: -4.45 to -2.74, P  < 0.01, I 2 : 84.7%, P  < 0.001), and significantly increased EF (WMD: 3.119, 95% CI: 2.165 to 4.082, P  < 0.01, I 2 : 82.9%, P  < 0.0 L) and FS (WMD: 3.157, 95% CI: 2.218 to 4.097, P  < 0.001, I 2 : 81.3%, P  < 0.001)., Discussion: The results show that the pre-administration of saponins from TCM has a significant protective effect on MIRI in preclinical studies, which provides an application prospect for developing anti-MIRI drugs with high efficiency and low toxicity., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 Sun, Fan, Yang, Su, Li, Tian, Liu and Xing.)

Previous studies have demonstrated that calcium-/calmodulin-dependent protein kinase II (CaMKII) and calcineurin A-nuclear factor of activated T-cell (CnA-NFAT) signaling pathways play key roles in cardiac hypertrophy (CH). However, the interaction between CaMKII and CnA-NFAT signaling remains unclear. H9c2 cells were cultured and treated with angiotensin II (Ang II) with or without silenced CaMKII δ (siCaMKII) and cyclosporine A (CsA, a calcineurin inhibitor) and subsequently treated with Wenxin Keli (WXKL). Patch clamp recording was conducted to assess L-type Ca 2+ current (I Ca-L ), and the expression of proteins involved in signaling pathways was measured by western blotting. Myocardial cytoskeletal protein and nuclear translocation of target proteins were assessed by immunofluorescence. The results indicated that siCaMKII suppressed Ang II-induced CH, as evidenced by reduced cell surface area and I Ca-L . Notably, siCaMKII inhibited Ang II-induced activation of CnA and NFATc4 nuclear transfer. Inflammatory signaling was inhibited by siCaMKII and WXKL. Interestingly, CsA inhibited CnA-NFAT pathway expression but activated CaMKII signaling. In conclusion, siCaMKII may improve CH, possibly by blocking CnA-NFAT and MyD88 signaling, and WXKL has a similar effect. These data suggest that inhibiting CaMKII, but not CnA, may be a promising approach to attenuate CH and arrhythmia progression., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2020 Na An et al.)

Objective: MicroRNAs (miRNAs) are reported to have crucial roles in human cancers; however, their role in colorectal cancer (CRC) remains largely unknown., Methods: In this study, we analyzed the expression of miR-4324 in CRC cell lines using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). We also examined miR-4324 expression in CRC tumor tissues using a miRNA expression dataset obtained from the Gene Expression Omnibus. We validated the connection between miR-4324 and homeobox B2 (HOXB2) using a luciferase activity reporter assay and western blotting. The effects of miR-4324 and HOXB2 on CRC cell malignant behaviors in vitro were further investigated., Results: miR-4324 expression was significantly decreased in both CRC tumor tissues and cell lines. Overexpression of miR-4324 suppressed CRC cell proliferation, migration, and invasion. In contrast, overexpression of HOXB2 promoted CRC malignant cell behaviors. Furthermore, we validated HOXB2 as a direct target of miR-4324., Conclusions: miR-4324 expression was decreased in CRC. miR-4324 regulates CRC cell proliferation, migration, and invasion by targeting HOXB2.

TRAF-binding domain (Trabid), one of deubiquitination enzymes, was recently reported to activate Wnt/ β-catenin signaling pathway. However, the role of Trabid in tumors including hepatocellular carcinoma (HCC) and the underlying mechanisms controlling its activity remain poorly understood. Here, we report that Trabid is significantly downregulated in HCC tumor samples and cell lines compared with normal controls and that its expression level is negatively correlated with HCC pathological grading, recurrence, and metastasis. The reintroduction of Trabid expression in tumor cells significantly decreases HCC progression as well as pulmonary metastasis. The effect of Trabid on HCC development occurs at least partially through regulation of Twist1 activity. Mechanistically, Trabid forms a complex with Twist1 and specifically cleaves RNF8-induced K63-linked poly-ubiquitin chains from Twist1, which enhances the association of Twist1 with β-TrCP1 and allows for subsequent K48-linked ubiquitination of Twist1. Knockdown of Trabid increases K63-linked ubiquitination, but abrogates K48-linked ubiquitination and degradation of Twist1, thus enhancing HCC growth and metastasis. Interestingly, Twist1 negatively regulates the promoter activity of Trabid, indicating that a double-negative feedback loop exists. Our findings also identify an essential role for activation of Trabid by AKT-mediated phosphorylation at Ser78/Thr117 in negatively regulating Twist1 signaling, which further provides insights into the mechanisms by which Trabid regulates Twist1 ubiquitination. Our results reveal that Trabid is a previously unrecognized inhibitor of HCC progression and metastasis, which sheds light on new strategies for HCC treatment.