LncRNA Meg3 Aggravates Renal Fibrosis Caused by Unilateral Ureteral Obstruction in Rats by Activating the Hedgehog Pathway

Background: The hedgehog signaling pathway exerts vital functions in regulating epithelial-to-mesenchymal transition (EMT) in renal interstitial fibrosis (RIF). It was reported that lncRNA-maternally expressed gene 3 (lncRNA Meg3) can regulate hepatic fibrosis by regulating the expression of smoothened (Smo) in the hedgehog signaling pathway. However, the specific role of lncRNA Meg3 in renal fibrosis resulting from unilateral ureteral obstruction (UUO) by regulating the hedgehog signaling pathway has not been reported. Hence, this research aimed to expound the effects of lncRNA Meg3 on renal fibrosis induced by UUO in rats via the hedgehog pathway. Methods: Peripheral blood was collected from patients with chronic kidney disease (CKD, CKD group) and healthy volunteers (Normal group) at the same period. In addition, 6-week-old male Sprague-Dawley (SD) rats were divided to Sham, UUO, UUO+shRNA Negative control (shNC), and UUO+sh-Meg3 groups, and their kidney tissues and serum were gathered. Next, quantitative real-time polymerase chain reaction (qRT-PCR) was employed for detecting the lncRNA Meg3 expression level in the serum of patients and renal tissue of rats; kits for testing levels of blood urea nitrogen (BUN), creatinine (Cr), hydroxyproline (HYP), and 24-hour urine protein (24-up) in rats of each group; hematoxylin and eosin (HE) staining and Masson staining for observing kidney tissue and renal fibrosis level in rats; western blot for measuring levels of collagen type III (Col III), α-Smooth muscle actin (α-SMA), fibronectin, E-cadherin, sonic hedgehog (Shh), patched (Ptch) protein, smoothened (Smo) protein and glioma-associated oncogene homolog 1 (Gli1) protein expression. Results: LncRNA Meg3 was highly expressed in CKD patients and UUO rats (p < 0.01). In contrast to the UUO+shNC group, knocking down lncRNA Meg3 improved renal injury, relieved pathological renal lesions, and reduced kidney fibrosis and related protein levels. It inhibited the hedgehog pathway in kidney tissues of UUO rats (p < 0.05 and p < 0.01). Conclusions: LncRNA Meg3 can aggravate UUO-induced rat renal fibrosis by activating the hedgehog pathway.