Table 1.

MiRNAs of importance for β-cell failure

β-Cell failure
miRNAs	Effects
miR-7	Represses β-cell function,34 regulates GLP-1-mediated insulin release.49
miR-9	Represses β-cell function.37
miR-15a	Regulates insulin synthesis.33
miR-17-92 cluster	Regulates β-cell replication, restoration and adaptation, and GSIS.24
miR-24	Reduces insulin promoter activity and insulin mRNA levels and consequently insulin content.33,39
miR-25	Its overexpression leads to inhibition of insulin biosynthesis and increased β-cell apoptosis.27
miR-26	Reduces insulin promoter activity and insulin mRNA levels and consequently insulin content.33,39
miR-29 family	Its overexpression negatively affects GSIS and β-cell proliferation.45
miR-30d	Increases insulin gene expression.32
miR-34a	Its overexpression results in sensitization to apoptosis and impaired nutrient-induced insulin secretion.26
miR-92b	Its overexpression leads to inhibition of insulin biosynthesis and increased β-cell apoptosis.27
miR-96	Represses β-cell function.38
miR-124a	Promotes β-cell dysfunction and death.43
miR-125b-5p	Its down-regulation reduces insulin sensitivity and deregulates β-cell function.46
miR-130a/b	Negatively correlated with insulin exocytosis.15
miR-132	Controls β-cell identity,48 proliferation and survival,51 regulates GLP-1-mediated insulin release.50
miR-146	Its overexpression results in sensitization to apoptosis and impaired nutrient-induced insulin secretion.26
miR-148	Reduces insulin promoter activity and insulin mRNA levels and consequently insulin content.33,39
miR-152	Negatively correlated with insulin exocytosis.15
miR-153	Its overexpression induces insulin secretion defects.28
miR-181b	Regulates β-cell replication and GSIS.24
miR-182	Reduces insulin promoter activity and insulin mRNA levels and consequently insulin content.33,39
miR-187	Negatively correlated with GSIS.42
miR-200 family	Represses β-cell function.35,166
miR-204	Blocks insulin production,47 promotes β-cell ER stress.52
miR-212	Regulates GLP-1-mediated insulin release.50
miR-216a	Its knockout leads to a reduction in islet size, β-cell mass, and insulin levels.25
miR-223	Its overexpression drives the compensatory β-cell expansion and the maintenance of functional β-cell mass during metabolic stress.22
miR-299-5p	Its reduction promotes β-cell dysfunction and loss.31
miR-320a	Its overexpression initiates pancreatic islet dysfunction by increasing the ROS level, inhibiting proliferation, and inducing apoptosis.29
miR-335	Negatively correlated with insulin exocytosis.41
miR-375	Regulates β-cell adaptation to metabolic stress and insulin resistance19 and promotes GSIS33
miR-383	Its overexpression reverses β-cell apoptosis and oxidative stress.30
miR-455	Its overexpression drives the compensatory β-cell expansion and the maintenance of functional β-cell mass during metabolic stress.23
miR-770-5p	Promotes β-cell dysfunction and death.44

ER, endoplasmic reticulum; GLP-1, glucagon-like peptide-1; GSIS, glucose-stimulated insulin secretion; miRNA, microRNA; mRNA, messenger RNA; ROS, reactive oxygen species.