Gm12664-201, A Pseudogene-Transcribed RNA Promotestriglyceride Accumulation Via Activating Endoplasmic Reticulum Stress Pathway in Hepatocytes

Abstract Background: Typical pseudogenes expressions have been reported to been associated with liver diseases. However, whether pseudogenes contribute to non-alcoholic fatty liver disease (NAFLD) and triglyceride (TG) accumulation and the underlying molecular mechanisms are poorly understood. We aimed to elucidate the role of Gm12664-201 in TG accumulation and the potential mechanism. Method and Results: We identified Gm12664-01 in high-fat diet (HFD) fed mice using microarray and confirmed its expression in both vivo and vitro high fat models with quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Then changed the level of Gm12664-201 in vitro to determine the role of it in TG accumulation, which evaluated by Oil red O staining and enzymatic method. The underlying mechanisms of Gm12664-01 in TG accumulation were investigated by detecting signaling markers BiP, PERK, ATF6, CHOP, eIF2α, XBP1 and ATF4 with qRT-PCR and western blotting. We found that Gm12664-201 was markedly increased in liver tissue of HFD mice and steric acid (SA) incubated AML-12 cells. Gm12664-201 overexpression rendered AML-12 cells susceptible to triglyceride (TG) accumulation, and silencing pseudogene Gm12664-201 expression efficiently alleviated SA-induced TG accumulation. Further studies revealed that Gm12664-201 regulates endoplasmic reticulum stress signaling markers BiP, PERK, ATF6, CHOP, eIF2α, XBP1 and ATF4 expression, which may be responsible for increased TG accumulation in hepatocytes. Conclusions: Upregulation of pseudogene Gm12664-201 induced by HFD promotes triglyceride accumulation and activates ER stress pathway in hepatocytes.