LncRNA NONRATT021972 siRNA attenuates P2X7 receptor expression and inflammatory cytokine production induced by combined high glucose and free fatty acids in PC12 cells

Abstract

Diabetic neuropathy (DNP) is a frequent chronic complication of diabetes mellitus with potentially lifethreatening outcomes. High glucose and elevated free fatty acids (FFAs) have been recently recognized as major causes of nervous system damage in diabetes. Our previous study has indicated extracellular stimuli, such as high glucose and/or FFA stress, may activate the p38 mitogen-activated protein kinase (MAPK) signaling pathway and induce a p38 MAPK-dependent sensitization of the P2X7 receptor and release of inflammatory factors in PC12 cells, while the mechanisms underlying remain to be elucidated. Long noncoding RNAs (lncRNAs) play important roles in diverse biological processes, including activation of a series of pathway signalings. Here, we showed combined high D-glucose and FFAs ( H G H F ) i n d u c e d a n i n c r e m e n t o f l n c R N A -NONRATT021972 (NONCODE ID, nc021972) in PC12 cells. Nc021972 small interference RNA (siRNA) alleviated HGHF-induced activation of p38 MAPK, expression of the P2X7 receptor, and [Ca 2+ ] i increment upon P2X7 receptor activation. Further experiments showed that there existed a crosstalk between nc021972 and the p38 MAPK signaling pathway. Inhibition of p38 MAPK signaling decreased nc021972-induced expression of the P2X7 receptor and [Ca 2+ ] i increment upon P2X7 receptor activation. Also, nc021972 siRNA inhibited HGHF-induced PC12 release of TNF-α and IL-6 and rescued decreased cell viability mediated by the P2X7 receptor. Therefore, inhibition of nc021972 may serve as a novel therapeutic strategy for diabetes complicated with nervous inflammatory diseases.

The Big Entity of New RNA World: Long Non-Coding RNAs in Microvascular Complications of Diabetes

“…Diabetic neuropathy is also a chronic complication of diabetes and has potential life-threatening consequences ( 54 ). Several reports have shown that lncRNAs act as important players in the pathophysiology of DNP (Figure 3 ).…”

Long non‑coding RNA BC168687 small interfering RNA reduces high glucose and high free fatty acid‑induced expression of P2X7 receptors in satellite glial cells

“…To imitate hyperglycemia and dyslipidemia, 40 mM D-glucose (Beijing Solarbio Science and Technology, Ltd.) and 0.60 mM FFAs were added to DMEM/F12 medium. FFAs were a mixture of oleate (Sigma-Aldrich; Merck KGaA, Darmstadt, Germany) and palmitate (Sigma-Aldrich, Merck KGaA) at a 2:1 ratio (w/w) ( 23 , 24 ). In addition, 20 mM D-Mannitol (Beijing Solarbio Science and Technology) was added into DMEM/F12 as an isotonic control.…”

Functional roles of lncRNAs and its potential mechanisms in neuropathic pain

“…2). For instance, small inhibitory RNA to lncRNA NON-RATT021972 and uc.48+ can downregulate rat P2X7 and P2X3 receptor expression in NP, which reduced the release of inflammatory cytokines, inhibited the excitability of DRG neurons, and reduced mechanical and thermal hyperalgesia in T2DM rats [46][47][48][49][50]. In a clinical study, researchers found that NONRATT021972 has abnormally increased expression in the DRG and serum of diabetic patients and diabetic rats, and the data indicated that NONRATT021972 was positively associated with neuropathic pain scores of type 2 diabetes [51].…”

“…This receptor is engaged both in inflammation and in NP. Researchers have shown that small inhibitory RNA to NONRATT021972, uc.48+, and BC168687 can inhibit the expression of P2X7 receptor expression in a DNP rat model and modulate ion channel expression, thereby alleviating the symptoms of NP [46,47,50,53,54]. In addition, researchers used bioinformatics and found that calcium ion transport was the second most significant biological process of differentiate expressed lncRNAs [24].…”