The diagnostic value and molecular mechanisms of LncRNA ZFAS1 in neuropathic pain

Long non-coding RNA (lncRNA) has been playing an increasingly significant role in neuropathic pain (NP). This study aimed to investigate the clinical significance and mechanism of LncRNA ZNFX1 antisense RNA 1 (ZFAS1) in NP.

92 patients with NP and 85 healthy controls were enrolled, and a rat NP model was constructed by chronic constrictive injury (CCI). LPS-induced microglia BV2 cells were used to construct an in vitro cellular model. RT-qPCR analysis of the mRNA levels of ZFAS1, miR-421, and Iba-1 (markers of microglia activation). Paw withdrawal threshold (PWT) and paw withdrawal latency (PWL) were used to assess mechanosensitive and thermal nociceptive allergic responses. ELISA assay for pro-inflammatory factors and anti-inflammatory factors expression. ROC assay for the diagnostic value of ZFAS1. Validation of the targeting between ZFAS1 and miR-421 by dual luciferase reporter assay.

ZFAS1 significantly increased while miR-421 significantly decreased in individuals with NP, in a rat model of CCI, and in LPS-induced microglial cells. Functionally, miR-421 directly targeted ZFAS1. ZFAS1 levels could significantly differentiate between NP patients and control (AUC = 0.910). Low expression of ZFAS1 significantly alleviated PWL and PWT in CCI rats. Elevated neuro-proinflammatory factors and decreased anti-inflammatory factors in CCI rats were significantly reversed by low expression of ZFAS1, but this is partially weakened by low expression of miR-421. Moreover, silencing ZFAS1 hindered the upregulation of Iba-1 expression induced by LPS, which was rescued significantly by miR-421.

Elevated ZFAS1 is a potential bio-diagnostic marker for NP. Inhibition of ZFAS1 may alleviate NP progression by inhibiting microglia activation and neuro-inflammatory responses.