Expression Silencing of Mitogen-Activated Protein Kinase 8 Interacting Protein-1 Conferred Its Role in Pancreatic β-Cell Physiology and Insulin Secretion.

Autor: Saeed R; Department of Microbiology and Immunology, Faculty of Pharmacy, Ain Shams University, Cairo 11566, Egypt.; Sharjah Institute for Medical Research, University of Sharjah, Sharjah 27272, United Arab Emirates., Mohammed AK; Sharjah Institute for Medical Research, University of Sharjah, Sharjah 27272, United Arab Emirates., Saleh SE; Department of Microbiology and Immunology, Faculty of Pharmacy, Ain Shams University, Cairo 11566, Egypt., Aboshanab KM; Department of Microbiology and Immunology, Faculty of Pharmacy, Ain Shams University, Cairo 11566, Egypt., Aboulwafa MM; Department of Microbiology and Immunology, Faculty of Pharmacy, Ain Shams University, Cairo 11566, Egypt.; Faculty of Pharmacy, King Salman International University, Ras-Sudr 46612, Egypt., Taneera J; Sharjah Institute for Medical Research, University of Sharjah, Sharjah 27272, United Arab Emirates.; Department of Basic Sciences, College of Medicine, University of Sharjah, Sharjah 27272, United Arab Emirates.
Jazyk: angličtina
Zdroj: Metabolites [Metabolites] 2023 Feb 20; Vol. 13 (2). Date of Electronic Publication: 2023 Feb 20.
DOI: 10.3390/metabo13020307
Abstrakt: Mitogen-activated protein kinase 8 interacting protein-1 (MAPK8IP1) gene has been recognized as a susceptibility gene for diabetes. However, its action in the physiology of pancreatic β-cells is not fully understood. Herein, bioinformatics and genetic analyses on the publicly available database were performed to map the expression of the MAPK8IP1 gene in human pancreatic islets and to explore whether this gene contains any genetic variants associated with type 2 diabetes (T2D). Moreover, a series of functional experiments were executed in a rat insulinoma cell line (INS-1 832/13) to investigate the role of the Mapk8ip1 gene in β-cell function. Metabolic engineering using RNA-sequencing (RNA-seq) data confirmed higher expression levels of MAPK8IP1 in human islets compared to other metabolic tissues. Additionally, comparable expression of MAPK8IP1 expression was detected in sorted human endocrine cells. However, β-cells exhibited higher expression of MAPK8IP1 than ductal and PSC cells. Notably, MAPK8IP1 expression was reduced in diabetic islets, and the expression was positively correlated with insulin and the β-cell transcription factor PDX1 and MAFA. Using the TIGER portal, we found that one genetic variant, "rs7115753," in the proximity of MAPK8IP1, passes the genome-wide significance for the association with T2D. Expression silencing of Mapk8ip1 by small interfering RNA (siRNA) in INS-1 cells reduced insulin secretion, glucose uptake rate, and reactive oxygen species (ROS) production. In contrast, insulin content, cell viability, and apoptosis without cytokines were unaffected. However, silencing of Mapk8ip1 reduced cytokines-induced apoptosis and downregulated the expression of several pancreatic β-cell functional markers including, Ins1 , Ins2 , Pdx1 , MafA , Glut2 , Gck , Insr , Vamp2 , Syt5 , and Cacna1a at mRNA and/or protein levels. Finally, we reported that siRNA silencing of Pdx1 resulted in the downregulation of MAPK8IP1 expression in INS-1 cells. In conclusion, our findings confirmed that MAPK8IP1 is an important component of pancreatic β-cell physiology and insulin secretion.
Databáze: MEDLINE