miR-155-5p alleviates ethanol-induced myocardial insulin resistance in H9C2 cells via regulating the mTOR signalling pathway

MiR-155 enhances phagocytosis of alveolar macrophages through the mTORC2/RhoA pathway

Alveolar macrophage phagocytosis is significantly reduced in Chronic obstructive pulmonary disease, and cigarette smoke extract is one of the chief reasons for this decrease. Nevertheless, the specific underlying mechanism remains elusive. In this study, the role and possible mechanism of miR-155-5p/mTORC2/RhoA in the phagocytosis of mouse alveolar macrophages (MH-S) were explored. Our results revealed that cigarette smoke extract intervention reduced MH-S cell phagocytosis and miR-155-5p expression. Meanwhile, the dual-luciferase reporter assay validated that Rictor is a target of miR-155-5p. On the one hand, transfecting miR-155-5p mimic, mimic NC, miR-155-5p inhibitor, or inhibitor NC in MH-S cells overexpressing miR-155-5p increased the Alveolar macrophage phagocytotic rate, up-regulated the expression level of RhoA and p-RhoA, and down-regulated that of mTOR and Rictor mRNA and protein. On the other hand, inhibiting the expression of miR-155-5p lowered the phagocytotic rate, up-regulated the expression of mTOR, Rictor mRNA, and protein, and down-regulated the expression of RhoA and p-RhoA, which taken together, authenticated that miR-155-5p participates in macrophage phagocytosis via the mTORC2/RhoA pathway. Finally, confocal microscopy demonstrated that cells overexpressing miR-155-5p underwent cytoskeletal rearrangement during phagocytosis, and the phagocytic function of cells was enhanced, signaling that miR-155-5p participated in macrophage skeletal rearrangement and enhanced alveolar macrophage phagocytosis by targeting the expression of Rictor in the mTORC2/RhoA pathway.

Shen-Qi-Jiang-Tang granule ameliorates diabetic nephropathy via modulating tumor necrosis factor signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Shen-Qi-Jiang-Tang granule (SQJTG), a classic traditional Chinese medicine (TCM) prescription, has been widely used in clinical for diabetes, especially type Ⅱ diabetes. Previous anti-diabetic studies stumbled across that SQJTG has a potential kidney protective effect on diabetic nephropathy (DN). However, the protective mechanism of SQJTG on DN still needs to be explored.

AIM OF THE STUDY

The purpose of the present study was to explore the therapeutic effect of SQJTG on DN through both bioinformatics analysis and in vivo experiments.

METHODS AND MATERIALS

The TCMIP database was used for screening potential compounds and targets of SQJTG, and the GeneCards, OMIM, DrugBank, and TTD databases were used for collecting DN-related genes. Then protein-protein interaction analysis for the common targets of SQJTG and DN was performed by the STRING database. Meanwhile, KEGG and GO were carried out using the Metascape and DAVID databases. In vivo experiments, to testify the potential kidney protective effects of SQJTG, STZ-induced DN mice with different dosages of SQJTG treatment were collected and the renal tissues were detected by H&E, PAS, Masson and TUNEL staining. Immunohistochemistry and immunoblotting were used to assess the proteins' expressions. Flow cytometry and ELISA assay were used to detect the levels of pro-inflammatory cytokines.

RESULTS

Among the 338 compounds ascertained by SQJTG, there were 789 related targets as well. Moreover, 1,221 DN-related targets were predicted and 20 core targets were screened by the PPI analyses. According to GO and KEGG pathway analysis, SQJTG may affect DN via the TNF pathway. For the in vivo experiments, renal histomorphological examinations demonstrated that SQJTG treatment significantly ameliorated STZ-induced kidney damage and had a dosage dependence. Meanwhile, mice with DN were found to have dramatic increases in IL-1, TNF-α, IL-6, and IL-12, but markedly decreased after administration of SQJTG. In addition, the protein levels of TNF signaling molecules, like p-P65, p-JNK, and p-p38, showed significantly elevated in kidney tissues of DN mice and attenuated after SQJTG treatment.

CONCLUSIONS

SQJTG exerts a kidney protective effect in DN mice via modulating TNF signaling pathways, and it has promising applications for the treatment of DN.

miR-155-5p upregulation ameliorates myocardial insulin resistance via mTOR signaling in chronic alcohol drinking rats

Background

Chronic alcohol intake is associated with an increased risk of alcoholic cardiomyopathy, which may present with pathological changes such as myocardial insulin resistance, leading to ventricular dilation and cardiac dysfunction. Although a correlation between microRNA-155 (miR-155) and insulin signaling has been identified, the underlying mechanism has not been elucidated to date. The purpose of the study was to determine whether overexpression of miR-155-5p in vivo could ameliorate chronic alcohol-induced myocardial insulin resistance and cardiac dysfunction.

Material and Methods

Wistar rats were fed with either alcohol or water for 20 weeks to establish chronic alcohol intakes model. Then the alcohol group were divided into three groups: model group, miRNA-155 group and AAV-NC group. Rats undergoing alcohol treatment were injected with AAV-miRNA-155 (adeno-associated virus 9) or its negative control AAV-NC, respectively. Gene expression was determined by real-time PCR, and protein expression was determined by western blot. Echocardiography was performed to assess terminal cardiac function. Insulin responsiveness was determined through the quantification of phosphorylated insulin receptor substrate 1 (ser 307) and phosphorylated insulin receptor (Tyr 1185) levels.

Results

We found that cardiac function was attenuated in chronic alcohol intake rats, with an activated mammalian target of rapamycin (mTOR) signaling pathway, accompanied by an increase in p-IRS1(ser 307) and a decrease in p-IR (Tyr 1185) level in myocardial tissue. Also, alcohol drinking significantly up-regulated miR-155-5p level and its overexpression decreased p-IRS1 (ser 307) and increased p-IR (Tyr 1185) levels, and meanwhile inhibited the mTOR signaling pathway.

Conclusion

miR-155-5p upregulation ameliorates myocardial insulin resistance via the mTOR signaling in chronic alcohol drinking rats. We propose that miR-155 may serve as a novel potential therapeutic target for alcoholic heart disease.