GBA3: a polymorphic pseudogene in humans that experienced repeated gene loss during mammalian evolution

GBA3 promotes fatty acid oxidation and alleviates non-alcoholic fatty liver by increasing CPT2 transcription

BACKGROUND

Excessive lipids accumulation and hepatocytes death are prominent characteristics of non-alcoholic fatty liver disease (NAFLD). Nonetheless, the precise pathophysiological mechanisms are not fully elucidated.

METHODS

HepG2 cells stimulated with palmitic acids and rats fed with high-fat diet were used as models for NAFLD. The impact of Glucosylceramidase Beta 3 (GBA3) on fatty acid oxidation (FAO) was assessed using Seahorse metabolic analyzer. Lipid content was measured both in vitro and in vivo. To evaluate NAFLD progression, histological analysis was performed along with measurements of inflammatory factors and liver enzyme levels. Western blot and immunohistochemistry were employed to examine the activity levels of necroptosis. Flow cytometry and reactive oxygen species (ROS) staining were utilized to assess levels of oxidative stress.

RESULTS

GBA3 promoted FAO and enhanced the mitochondrial membrane potential without affecting glycolysis. These reduced the lipid accumulation. Rats supplemented with GBA3 exhibited lower levels of inflammatory factors and liver enzymes, resulting in a slower progression of NAFLD. GBA3 overexpression reduced ROS and the ratio of cell apoptosis. Phosphorylation level was reduced in the essential mediator, MLKL, implicated in necroptosis. Mechanistically, as a transcriptional coactivator, GBA3 promoted the expression of Carnitine Palmitoyltransferase 2 (CPT2), which resulted in enhanced FAO.

CONCLUSIONS

Increased FAO resulting from GBA3 reduced oxidative stress and the production of ROS, thereby inhibiting necroptosis and delaying the progression of NAFLD. Our research offers novel insights into the potential therapeutic applications of GBA3 and FAO in the management and treatment of NAFLD.