Table 1. Dysregulated lncRNAs involved in DR.

LncRNA	Dysregulation	Tissues and cell type	Pathogenic functions	Possible mechanism	References
MIAT	Up-regulated	Retinas of DM rats; RF/6A, RPE, RGC and Müller cells	Promotes EC proliferation, migration, and tube formation in vitro	NF-κB activation	[96–98]
			Aggravates retinal vessel impairments and visual dysfunction in vivo
MALAT1	Up-regulated	Retinas of DM mice; RF/6A	Promotes EC proliferation, migration, and tube formation in vitro	Cross-talks with p38 MAPK signaling pathway	[99–101]
			Deteriorates retinal NV in vivo	Activates inflammatory pathway via TNF-α and IL-6
MEG3	Down-regulated	Retinas of DM mice; RF/6A	Regulates ECl proliferation, migration, and tube formation in vitro	Activates PI3K-Akt signaling pathway	[102]
			Aggravates retinal vessel dysfunction in vivo
SOX2OT	Down-regulated	Retinas of DM mice; RGCs	Decreases cell viability and increases cell apoptosis in vitro	Antioxidative via regulation of NRF2/HO-1 signaling activity	[103]
			Promotes neurodegeneration in vivo
RNCR3	Up-regulated	Retinas of DM mice; RF/6A, Müller cells	Increases cell viability and proliferation, promotes EC migration and tube formation in vitro	Related to the release of several cytokines	[104,105]
			Aggravates retinal cell apoptosis, visual function, and microvascular leakage in vivo
ANRIL	Up-regulated	Retinas of DM mice; HRECs	Increases retinal microvascular permeability in vivo	Increases VEGF mediated by PRC2 complex and p300	[106]
BDNF-AS	Up-regulated	ARPE-19	Increases cell apoptosis in vitro	Not only via BDNF-associated pathways	[107,108]

Abbreviations: ANRIL, antisense RNA to INK4 locus; BDNF-AS, brain-derived neurotrophic factor antisense; MALAT1, metastasis-associated lung adenocarcinoma transcript 1; MEG3, maternally expressed gene 3; MIAT, myocardial infarction associated transcript; NRF2/HO-1, nuclear factor erythroid 2 related factor 2/heme oxygenase-1; PRC2, polycomb repressor complex 2; RNCR2, retinal ncRNA 2; SOX2OT, SOX2 overlapping transcript.