Changes in the expression levels of CB1 and GLP‐1R mRNAs and microRNAs 33a and 122 in the liver of type 2 diabetic rats treated with ghrelin

CircRNA circ-ITCH improves renal inflammation and fibrosis in streptozotocin-induced diabetic mice by regulating the miR-33a-5p/SIRT6 axis

Diabetic nephropathy (DN) seriously affects the people's life and health in China. This study aimed to investigate the effect of circRNA circ-ITCH on improving DN by regulating the miR-33a-5p/SIRT6 axis and the possible mechanism of action. High glucose (HG)-induced rat mesangial cells (RMCs) were used to simulate the DN in vitro. Reverse transcription-quantitative PCR (RT-qPCR) and western blot analysis were conducted to detect the gene or protein expression. Cell Counting Kit-8 (CCK-8) and wound healing assays were performed to estimate the cell viability and migration capability. Immunofluorescence and enzyme-linked immunosorbent assay (ELISA) were used to detect the α-Smooth Muscle Actin (α-SMA) expression and levels of inflammatory factors. The potential associations between circ-ITCH and miR-33a-5p, miR-33a-5p and SIRT6 in RMCs were measured via dual-luciferase reporter assay. Streptozotocin (STZ) was used to induce the diabetic mice. Blood glucose and serum insulin of mice were determined by corresponding kits, and blood urea nitrogen (BUN) and serum creatinine (SCr) were measured using an automatic biochemical analyzer. Hematoxylin and eosin (H&E) staining and periodic acid-Schiff (PAS) staining were applied to observe the degree of pathological injury and fibrosis of renal tissues. The results of the present study revealed that circ-ITCH expression was obviously decreased in HG-induced RMCs. In addition, circ-ITCH overexpression inhibited the viability, migration, fibrosis and inflammatory response of HG-induced RMCs. Further experiments confirmed that miR-33a-5p may be a direct target of circ-ITCH and SIRT6 may be a direct target of miR-33a-5p. Notably, the miR-33a-5p mimic or shRNA-SIRT6 were discovered to reverse the inhibitory effects of circ-ITCH on the proliferation, migration, fibrosis and inflammatory response of HG-induced RMCs. Furthermore, circ-ITCH overexpression ameliorated renal inflammation and fibrosis in STZ-induced diabetic mice. In conclusion, circ-ITCH alleviated renal inflammation and fibrosis in STZ-induced diabetic mice by regulating the miR-33a-5p/SIRT6 axis.Author names: Please confirm if the author names are presented accurately and in the correct sequence (given name, middle name/initial, family name). Author 1 Given name: [ChunYang] Last name [Xu]. Author 2 Given name: [DingBo] Last name [Xu]. Author 3 Given name: [YongHua] Last name [Liu]. Author 4 Given name: [Juanjuan] Last name [Jiang]. Also, kindly confirm the details in the metadata are correct.ok.

Regulatory MicroRNAs in T2DM and Breast Cancer

MicroRNAs orchestrate the tight regulation of numerous cellular processes and the deregulation in their activities has been implicated in many diseases, including diabetes and cancer. There is an increasing amount of epidemiological evidence associating diabetes, particularly type 2 diabetes mellitus, to an elevated risk of various cancer types, including breast cancer. However, little is yet known about the underlying molecular mechanisms and even less about the role miRNAs play in driving the tumorigenic potential of the cell signaling underlying diabetes pathogenesis. This article reviews the role of miRNA in bridging the diabetes–breast cancer association by discussing specific miRNAs that are implicated in diabetes and breast cancer and highlighting the overlap between the disease-specific regulatory miRNA networks to identify a 20-miRNA signature that is common to both diseases. Potential therapeutic targeting of these molecular players may help to alleviate the socioeconomic burden on public health that is imposed by the type 2 diabetes mellitus (T2DM)–breast cancer association.

Oxidative stress and inflammatory response of ghrelin on myocardial and aortic tissues in insulin-resistant rats

OBJECTIVES

This study was designed to clarify the effects of ghrelin on myocardial and aortic tissues in insulin-resistant rats.

METHODS

Sprague-Dawley rats were divided into the following groups: control (Group 1), insulin resistance (IR, Group 2), ghrelin (Group 3) and IR+Ghrelin (Group 4) groups. Levels of HOMA-IR, fibronectin, hydroxyproline, collagen-1, collagen-3, matrix metalloproteinase-3, and matrix metalloproteinase-9, and tissue inhibitor of metalloproteinase-1, and oxidative stress parameters as protein carbonyl (PCO), lipid hydroperoxides (LHPs), malondialdehyde, total thiol were determined in myocardial tissue. Expressions of IL-6, NF-κB and TNF-α mRNAs were detected by RT-qPCR. Aorta tissue was stained Masson trichrome.

KEY FINDINGS

The HOMA-IR level decreased in the IR+Ghrelin group compared with the IR group (P < 0.001). The PCO and LHP concentrations were higher in the IR group compared with control rats (P < 0.05). The PCO level was reduced by ghrelin in the IR+Ghrelin group compared with the IR group (P < 0.001). Ghrelin treatment reduced the mRNA expression levels of IL-6, NF-κB and TNF-α in the IR+Ghrelin group compared with the IR group (P < 0.001). There was no difference among the groups in the histology of aortic tissue.

CONCLUSIONS

Ghrelin, a regulator of appetite and energy homeostasis, may be effective in regulating oxidative stress and the inflammatory response when impaired by IR. Therefore, ghrelin may reduce the risks of myocardial dysfunction in IR.