LncRNA NNT-AS1 regulates proliferation, ECM accumulation and inflammation of human mesangial cells induced by high glucose through miR-214-5p/smad4

Depression of LncRNA DANCR alleviates tubular injury in diabetic nephropathy by regulating KLF5 through sponge miR-214-5p

OBJECTIVE

Diabetic nephropathy (DN) manifests a critical aspect in the form of renal tubular injury. The current research aimed to determine the function and mechanism of long non-coding ribonucleic acid (LncRNA) differentiation antagonising non-protein coding RNA (DANCR), with a focus on its impact on renal tubular injury.

METHODS

Quantitative reverse transcription polymerase chain reaction was employed to analyze the RNA levels of DANCR in the serum of patients with DN or human proximal tubular epithelial cells (human kidney 2 [HK2]). The diagnostic significance of DANCR was assessed using a receiver operating characteristic curve. A DN model was established by inducing HK-2 cells with high glucose (HG). Cell proliferation, apoptosis, and the levels of inflammatory factors, reactive oxygen species (ROS), and malondialdehyde (MDA) were detected using the Cell Counting Kit - 8, flow cytometry, and enzyme-linked immunosorbent assay. The interaction between microRNA (miR)-214-5p and DANCR or Krüppel-like factor 5 (KLF5) was investigated using RNA immunoprecipitation and dual-luciferase reporter assays.

RESULTS

Elevated levels of DANCR were observed in the serum of patients with DN and HG-inducted HK-2 cells (P < 0.05). DANCR levels effectively identified patients with DN from patients with type 2 diabetes mellitus. Silencing of DANCR protected against HG-induced tubular injury by restoring cell proliferation, inhibiting apoptosis, and reducing the secretion of inflammatory factors and oxidative stress production (P < 0.05). DANCR functions as a sponge for miR-214-5p, and the mitigation of DANCR silencing on HG-induced renal tubular injury was partially attenuated with reduced miR-214-5p (P < 0.05). Additionally, KLF5 was identified as the target of miR-214-5p.

CONCLUSION

DANCR was identified as diagnostic potential for DN and the alleviation of renal tubular injury via the miR-214-5p/KLF5 axis, following DANCR silencing, introduces a novel perspective and approach to mitigating DN.

Hypoxia promotes immune escape of pancreatic cancer cells by lncRNA NNT-AS1/METTL3-HuR-mediated ITGB1 m6A modification

Pancreatic cancer (PC) cell immune escape is a crucial element in PC malignant development. Some previous studies have reported that LncRNA NNT-AS1 played a carcinogenic role in various tumors. However, the effect of lncRNA NNT-AS1 in PC cell immune escape remains unclear. To evaluate PC cell immune escape, PC cells were co-cultured with CD8+ T cells under a hypoxic condition. PC cell proliferation and migration were evaluated using the colony formation assay and transwell assay. CD8+ T cell proliferation and aoptosis were measured using the carboxy fluorescein diacetate succinimidyl ester (CFSE) assay and flow cytometry. The secretion of antitumor cytokines was assessed using enzyme-linked immunosorbent assay (ELISA). The molecular interactions were analyzed using chromatin immunoprecipitation (ChIP), RNA immunoprecipitation (RIP), or dual-luciferase reporter gene assays. A tumor xenograft model was established to evaluate the effects of lncRNA NNT-AS1 on PC in vivo. It was found that lncRNA NNT-AS1 was highly expressed in PC, and its silencing inhibited hypoxia-induced PC cell growth and immune escape in vivo and in vitro. Mechanically, HIF-1α transcriptionally activated NNT-AS1 expression and NNT-AS1 increased ITGB1 stability and expression in a METTL3-HuR dependent manner. ITGB1 overexpression reversed the inhibitory effects of NNT-AS1 knockdown on hypoxia-induced PC cell immune escape. In conclusion, Hypoxia promoted PC cell immune escape through lncRNA NNT-AS1/METTL3-HuR-mediated m6A modification to increase ITGB1 expression, which provided a theoretical foundation and a potential therapeutic target for PC.

Long Non-Coding RNAs in the Pathogenesis of Diabetic Kidney Disease

Diabetic kidney disease (DKD) is one of the major microvascular complications of diabetes mellitus, with relatively high morbidity and mortality globally but still in short therapeutic options. Over the decades, a large body of data has demonstrated that oxidative stress, inflammatory responses, and hemodynamic disorders might exert critical influence in the initiation and development of DKD, whereas the delicate pathogenesis of DKD remains profoundly elusive. Recently, long non-coding RNAs (lncRNAs), extensively studied in the field of cancer, are attracting increasing attentions on the development of diabetes mellitus and its complications including DKD, diabetic retinopathy, and diabetic cardiomyopathy. In this review, we chiefly focused on abnormal expression and function of lncRNAs in major resident cells (mesangial cell, endothelial cell, podocyte, and tubular epithelial cell) in the kidney, summarized the critical roles of lncRNAs in the pathogenesis of DKD, and elaborated their potential therapeutic significance, in order to advance our knowledge in this field, which might help in future research and clinical treatment for the disease.