Downregulation of hsa-miR-100-5p May Be a Protective Factor in the Early Stages of Nephropathy in Type 1 Diabetes Mellitus.

Type 1 Diabetes Mellitus (T1DM) can generate severe complications, such as Diabetic Kidney Disease (DKD) or Diabetic Nephropathy (DN), with it emerging as the leading cause of terminal (end-stage) renal disease all over the world. For T1DM, the clinical evaluation of DKD uses markers like the Glomerular Filtration Rate (GFR) and the Urinary Albumin Excretion (UAE). However, early diagnosis of DKD is still a challenge. For this reason, investigating molecular markers, such as microRNAs (miRNAs), offers a promising perspective to an early diagnosis, highlighting the stability and the ability to reflect incipient molecular manifestations. Thus, here we investigated four miRNAs (hsa-let-7i-5p, hsa-miR-143-3p, hsa-miR-501-3p, and hsa-miR-100-5p) regarding nephropathy in patients with T1DM, considering the albuminuria (micro and macro) as a standard to evaluate the groups. As a result, we found a reduced expression of miR-100-5p in patients with MIC, indicating a protective role in nephropathy. Beyond that, expression levels between the groups (Non vs. UAE) were not significant when comparing the miRNAs miR-501-3p and miR-143-3p. Finally, miR-143-3p and miR-100-5p were linked to some target genes such as AKT1, MMP13, and IGF1R, that are connected to signal pathways and cellular metabolism.

Global miRNA expression reveals novel nuclear and mitochondrial interactions in Type 1 diabetes mellitus.

Background: Considering the potential role of miRNAs as biomarkers and their interaction with both nuclear and mitochondrial genes, we investigated the miRNA expression profile in type 1 diabetes (T1DM) patients, including the pathways in which they are involved considering both nuclear and mitochondrial functions. Methods: We analyzed samples of T1DM patients and control individuals (normal glucose tolerance) by high throughput miRNA sequencing (miRNome). Next, five miRNAs - hsa-miR-26b-5p, hsa-let-7i-5p, hsa-miR-143-3p, hsa-miR-501-3p and hsa-miR-100-5p - were validated by RT-qPCR. The identification of target genes was extracted from miRTarBase and mitoXplorer database. We also performed receiver operating characteristic (ROC) curves and miRNAs that had an AUC > 0.85 were considered potential biomarkers. Results: Overall, 41 miRNAs were differentially expressed in T1DM patients compared to control. Hsa-miR-21-5p had the highest number of predicted target genes and was associated with several pathways, including insulin signaling and apoptosis. 34.1% (14/41) of the differentially expressed miRNAs also targeted mitochondrial genes, and 80.5% (33/41) of them targeted nuclear genes involved in the mitochondrial metabolism. All five validated miRNAs were upregulated in T1DM. Among them, hsa-miR-26b-5p showed AUC>0.85, being suggested as potential biomarker to T1DM. Conclusion: Our results demonstrated 41 DE miRNAs that had a great accuracy in discriminating T1DM and control group. Furthermore, we demonstrate the influence of these miRNAs on numerous metabolic pathways, including mitochondrial metabolism. Hsa-miR-26b-5p and hsa-miR-21-5p were highlighted in our results, possibly acting on nuclear and mitochondrial dysfunction and, subsequently, T1DM dysregulation.