Glucagon-like peptide-1 (GLP-1) is an incretin hormone that acts on the pancreas to increase insulin and decrease glucagon secretion. Albuminuria is the pivotal marker for diabetic nephropathy, which is the leading microvascular complication of diabetes mellitus. Most of the previous studies mainly focused on the clinical trials of the therapeutic renal protective effect after administration of GLP-1 receptor agonists (GLP-1 RAs), not prior to administration. Therefore, this study aimed to investigate the association between fasting plasma GLP-1 levels and albuminuria before GLP-1 RA administration. A cross-sectional study was designed to evaluate the association between fasting plasma GLP-1 levels and albuminuria in patients with type 2 diabetes mellitus (T2DM). A total of 68 T2DM participants were analyzed from the data at Wonkwang University Hospital in Iksan, Korea. Logistic regression analysis was performed to evaluate the odds ratio (OR) and 95% confidence interval (CI) of the incidence of albuminuria between the GLP-1 low group (Group L) and the high group (Group H). The OR (95% CI) for the incidence of albuminuria comparing the Group L with the Group H of fasting plasma GLP-1 levels was 3.410 (1.160-10.023), p = 0.026 after adjustment for age, gender, fasting plasma glucose, HbA1c, C-peptide, the use of ACE inhibitors or ARBs, SGLT-2 inhibitors, and DPP-4 inhibitors. As a continuous variable, the OR (95% CI) for the incidence of albuminuria associated with the reduction of each 1 pmol/L in fasting plasma GLP-1 levels was 1.673 (1.173-1.870), p = 0.018, after full adjustment. This study showed the negative association between fasting plasma GLP-1 levels and the incidence of albuminuria in Korean patients with T2DM, before GLP-1 RA administration. This result suggests that endogenous GLP-1 may play a role in attenuating albuminuria.

Background/Aim: microRNAs (miRNAs) are key regulators of both physiological and pathophysiological mechanisms in diabetes and gastrointestinal (GI) dysmotility. Our previous studies have demonstrated the therapeutic potential of miR-10a-5p mimic and miR-10b-5p mimic (miR-10a/b mimics) in rescuing diabetes and GI dysmotility in murine models of diabetes. In this study, we elucidated the safety profile of a long-term treatment with miR-10a/b mimics in diabetic mice. Methods: Male C57BL6 mice were fed a high-fat, high-sucrose diet (HFHSD) to induce diabetes and treated by five subcutaneous injections of miR-10a/b mimics for a 5-month period. We examined the long-term effect of the miRNA mimics on diabetes and GI dysmotility, including an assessment of cancer risk as well as liver and colon inflammation using cancer and inflammatory biomarkers. Results: HFHSD-induced diabetic mice subcutaneously injected with miR-10a/b mimics monthly for 5 months exhibited a marked reduction in fasting blood glucose levels with restoration of insulin and significant weight loss, improved glucose and insulin intolerance, and restored GI transit time. In addition, the miR-10a/b mimic treated diabetic mice showed no indication of risk for cancer development and inflammation induction in the liver, colon, and blood for the 5 months post injections. Conclusion: This longitudinal study demonstrates that miR-10a/b mimics, when subcutaneously administered in diabetic mice, effectively alleviate diabetes and GI dysmotility for 5 months with no discernible risk for cancer or inflammation in the liver and colon. The sustained efficacy and favorable safety profiles position miR-10a/b mimics as promising candidates in miRNA-based therapeutics for diabetes and GI dysmotility.

Gender and biological sex have distinct impacts on the pathogenesis of type 2 diabetes (T2D). Estrogen deficiency is known to predispose female mice to T2D. In our previous study, we found that high-fat, high-sucrose diet (HFHSD) induces T2D in male mice through the miR-10b-5p/KLF11/KIT pathway, but not in females, highlighting hormonal disparities in T2D susceptibility. However, the underlying molecular mechanisms of this hormonal protection in females remain elusive. To address this knowledge gap, we utilized ovariectomized, estrogen-deficient female mice, fed them a HFHSD to induce T2D, and investigated the molecular mechanisms pathway in estrogen-deficient diabetic female mice, cell lines, and patients with T2D in female. Initially, female mice fed a HFHSD exhibited delayed onset of T2D, but ovariectomy-induced estrogen deficiency promptly precipitated T2D without delay. Intriguingly, insulin (INS) was upregulated, while insulin receptor (INSR) and protein kinase B (AKT) were downregulated in these estrogen-deficient diabetic female mice, indicating insulin-resistant T2D. These dysregulations of INS, INSR, and AKT were mediated by a miR-10a/b-5p-NCOR2 axis. Treatment of miR-10a/b-5p effectively alleviated hyperglycemia in estrogen-deficient T2D female mice, while β-estradiol temporarily reduced hyperglycemia. Consistent with the murine findings, plasma samples from female T2D patients exhibited significant reductions in miR-10a/b-5p, estrogen, and INSR, but increased insulin levels. Our findings suggest that estrogen protect against insulin-resistant T2D in females through miR-10a/b-5p/NCOR2 pathway, indicating the potential therapeutic benefits of miR-10a/b-5p restoration in female T2D management.