miR-122 dysregulation is associated with type 2 diabetes mellitus-induced dyslipidemia and hyperglycemia independently of its rs17669 variant

Involvement of miRNAs in the Cluster of Metabolic Factors of MetS: Nutrition-Genome-MetS Axis

MicroRNAs (miRNAs) are key regulators of gene expression and play essential roles in physiological processes such as cell proliferation, apoptosis, and metabolism. They have emerged as promising biomarkers for the early diagnosis, prognosis, and treatment of Metabolic Syndrome (MetS). In recent years, exosome-derived miRNAs, known as "xeno-miRNAs", which are derived from food, as well as circulating miRNAs, have emerged as areas of intense research due to their potential effects on metabolic disorders. miRNAs influence fasting blood glucose and insulin resistance through mechanisms such as β-cell differentiation, insulin gene transcription, and PI3K-AKT pathway activation. Additionally, miRNAs play important roles in regulating MetS components, as follows: obesity through adipogenesis and lipogenesis; hypertension through regulation of the renin-angiotensin system and vascular tone; and dyslipidemia by modulating lipid metabolism. Emerging evidence suggests that nutrients such as polyphenols and specific dietary patterns can alter miRNA expression, potentially impacting metabolic health. Understanding the interactions between diet and miRNA regulation offers novel insights into the prevention and treatment of MetS. This review explores the mechanisms by which miRNAs influence MetS components, and highlights the growing potential of nutrient-regulated miRNAs as therapeutic targets within the framework of precision nutrition and personalized metabolic disease management.

Dysregulated microRNAs in type 2 diabetes and breast cancer: Potential associated molecular mechanisms

Type 2 diabetes (T2D) is a multifaceted and heterogeneous syndrome associated with complications such as hypertension, coronary artery disease, and notably, breast cancer (BC). The connection between T2D and BC is established through processes that involve insulin resistance, inflammation and other factors. Despite this comprehension the specific cellular and molecular mechanisms linking T2D to BC, especially through microRNAs (miRNAs), remain elusive. miRNAs are regulators of gene expression at the post-transcriptional level and have the function of regulating target genes by modulating various signaling pathways and biological processes. However, the signaling pathways and biological processes regulated by miRNAs that are associated with T2D and BC have not yet been elucidated. This review aims to identify dysregulated miRNAs in both T2D and BC, exploring potential signaling pathways and biological processes that collectively contribute to the development of BC.

Circulating afamin positively correlated with the miR-122 expression and type 2 diabetes mellitus-related phenotype according to the duration of diabetes

Background

Afamin is a hepatokine that involves in glucose and lipids metabolism. miR-122 is mainly expressed in liver and involves in lipid and carbohydrate metabolism. This study aimed at investigating the circulating afamin, its correlation with type 2 diabetes mellitus (T2DM) and miR-122 gene expression in T2DM patients and healthy control subjects according to the duration of diabetes.

Methods

This case-control study included 220 participants, with 100 individuals serving as controls and 120 individuals diagnosed with type 2 diabetes mellitus (T2DM). The miR-122 gene expression was assessed using real-time PCR. The serum concentration of biochemical parameters such as glucose levels, lipid profile, and small-dense low-density lipoprotein (sdLDL) were measured using colorimetric kits. Circulating afamin and insulin levels were assayed using an ELISA kit. Glycated hemoglobin (HbA1c) was measured using capillary electrophoresis.

Results

Circulating afamin level was significantly higher in T2DM patients compared to the control group, (73.8 ± 10.8 vs. 65.9 ± 8.7, respectively; P < 0.001). Similarly, miR122 expression was significantly increased in T2DM patients compared to healthy control subjects (4.24 ± 2.01 vs. 1.00 ± 0.85, respectively; P < 0.001). Among patients diagnosed with T2DM, those with longstanding diabetes (>5 years) exhibited significantly higher levels of circulating afamin and miR-122 expression compared to individuals with a shorter duration of diabetes (≤5 years) (P < 0.05). Circulating afamin levels were significantly correlated with waist circumference, small-dense low-density lipoprotein (sdLDL), fasting blood sugar (FBS), insulin, resistance to insulin, and miR-122 expression, depending on the duration of the disease (P < 0.05). Furthermore, the performance of afamin as a diagnostic marker for T2DM was confirmed through receiver operating characteristic (ROC) analysis, yielding an area under the curve (AUC) of 0.7 (P < 0.001).

Conclusions

Circulating afamin involved in the T2DM-related complications and its concentration is positively correlated to the miR-122 expression, especially in patient with longstanding diabetes.