Table 3.

miRNAs dysregulated in T1D

miRNAs	Origins	Effects	Targets	References
miR-326	Peripheral blood lymphocytes (+)	Associated with a state of ongoing autoimmunity	Ets-1, VDR	[65]
miR-21	β cells (+)	NF-κB−miR-21−PDCD4 axis controls islet β-cell death	PDCD4	[71,100]
	PBMCs (−)
miR-146	Cytokine treated islets (+), NOD mice islets, MIN6	Contribute to cytokine-mediated β-cell dysfunction	TRAF6, IRAK1	[70,72,101]
miR-34a			VAMP2, BclII
miR-29a/b/c			Mcl1
miR-101a			Neurod1
miR-30b			Neurod1
miR-375	Islet-specific miRNA	A potential biomarker of β-cell death and predictor of diabetes	?	[102]
	Serum (+)
miR-25	Serum (+)	Negatively associated with residual β-cell function, positively associated with glycemic control (HbA1c)	Bim and Trail	[103]
miR-181a	Serum (+)	Mediates pancreatic β cells dysfunction	SMAD7	[104]
miR-503	β cells (+)	Knockdown of miR-503 enhances insulin secretion of pancreatic β cells, promotes cell proliferation, and protects cells from apoptosis	mTOR pathway	[105]
microRNA-16-5p, -17-5p, and -20a-5p	Plasma (+)	Novel diagnostic biomarkers for gestational diabetes mellitus	?	[106]
miR-24, miR-26, miR-182, and miR-148	β cells	Specific knockdown of miR-24, miR-26, miR-182, or miR-148 in cultured β cells or isolated primary islets downregulates insulin promoter activity and insulin mRNA levels	Bhlhe22, Sox6	[107]
miR-33a	β cell	Influences insulin secretion	ABCA1	[108]
miR-125a-5p	Tregs (+)	Increased expression of miR-125a-5p on Tregs results in reduced CCR2, thus limiting their migration and eventual function in the pancreas	CCR2	[109]

(+), increased; (−), decreased; ?, unknown function. Ets-1: Erythroblastosis virus E26 oncogene homolog 1; miRNAs: MicroRNAs; T1D: Type 1 diabetes; Tregs: Regulatory T cells; VDR: Vitamin D receptor.