LncRNA NEAT1 accelerates renal tubular epithelial cell damage by modulating mitophagy via miR‐150‐5p–DRP1 axis in diabetic nephropathy

Abstract

Diabetic nephropathy (DN) is a severe complication in diabetic patients, with a high mortality rate. Renal tubular injury is involved in the pathogenesis of DN. In this study, we aimed to uncover the regulatory roles of the NEAT1-miR-150-5p-DRP1 axis in an in vitro model of DN and its possible mechanisms. High glucose-challenged HK-2 cells were used as an in vitro DN model. NEAT1, miR-150-5p and DRP1 levels were assessed by RT-qPCR. Cell viability was determined by the MTT assay. MitoSOX Red and JC-1 were used to evaluate intracellular production of reactive oxygen species and mitochondrial membrane potential, respectively. Lactate dehydrogenase release and superoxide dismutase activity were assessed with commercial kits. The protein levels of DRP1, p62, BECN1(beclin 1) and BNIP3 were determined by western blotting. The interaction between NEAT1 (DRP1) and miR-150-5p was verified by a dual-luciferase reporter assay and an RNA immunoprecipitation assay. Our results showed that in response to high glucose the NEAT1 and DRP1 levels were upregulated, whereas the miR-150-5p level was downregulated in HK-2 cells. Knockdown of NEAT1 or DRP1 in high glucose-challenged HK-2 cells inhibited excessive reactive oxygen species production and lactate dehydrogenase release, increased cell viability, mitochondrial membrane potential and superoxide dismutase activity and enhanced mitophagy. Inhibition of miR-150-5p resulted in the opposite results. Mechanistically, NEAT1 sponged miR-150-5p to increase the DRP1 level. Moreover, silencing of NEAT1 or DRP1 could counteract miR-150-5p inhibition-induced deleterious effects. Collectively, our findings indicate that NEAT1 facilitates high glucose-induced damage in HK-2 cells by suppressing mitophagy via the miR-150-5p-DRP 1 axis, which sheds light on a novel mechanism of DN.

The Interplay of NEAT1 and miR-339-5p Influences on Mesangial Gene Expression and Function in Various Diabetic-Associated Injury Models

“…As a structural component of nuclear paraspeckles [ 27 ], it binds RNAs causing their nuclear retention, which prevents their export to the cytoplasm and thus their translation [ 37 ]. NEAT1 modulates gene expression by sponging numerous miRNAs [ 28 , 29 , 30 , 31 , 38 ]. The exact mechanism needs to be elucidated since NEAT1 localizes to the nucleus while miRNAs have their place of action in the cytoplasm.…”

“…With regard to DKD, others showed a positive and negative correlation, respectively, between elevated urinary NEAT1 and various podocyte damage markers like synaptopodin and podocalyxin or GFR [ 42 ]. HG-exposed proximal tubular cells (HK-2) or murine MCs (mMCs) exhibited an increase in NEAT1 expression in a dose- or time- dependent manner [ 31 , 43 ]. Contrarily to others, our data indicate that NEAT1 expression is not affected by HG using an osmotic control and a species model, in which NEAT1 is annotated (human or murine) [ 31 , 43 , 44 ].…”

“…HG-exposed proximal tubular cells (HK-2) or murine MCs (mMCs) exhibited an increase in NEAT1 expression in a dose- or time- dependent manner [ 31 , 43 ]. Contrarily to others, our data indicate that NEAT1 expression is not affected by HG using an osmotic control and a species model, in which NEAT1 is annotated (human or murine) [ 31 , 43 , 44 ].…”

“…In humans, the short variant (3684 nucleotides), referred as NEAT1_1 , is produced by early 3′-end processing while the long NEAT1 _2 isoform (22743 nucleotides) is formed without poly(A) tail by RNase P cleavage at a tRNA-like structure [ 25 , 26 ]. As a structural element, NEAT1 comprises a core component of nuclear paraspeckles [ 27 ]; nevertheless, it also acts as competing endogenous RNA (ceRNA) [ 28 , 29 , 30 , 31 , 32 ] to de-repress [ 33 ] gene expression by competing with miRNAs for interaction with shared target mRNAs.…”

Mitophagy: An Emergence of New Player in Alzheimer’s Disease

“…Another study has revealed that lncRNA SNHG14 (small nucleolar RNA host gene 14), activates mitophagy by upregulating the expression of BNIP3, Beclin-1 and LC3II/LC3I ratio ( Deng et al, 2020 ). Also, the findings of a recent study uncovered that the lncRNA NEAT1(nuclear paraspeckle assembly transcript 1)- miR-150-5p-DRP1 axis regulates mitophagy ( Yang et al, 2021 ). There are several studies published in recent years confirming epigenetic regulation of mitophagy.…”