Deletion of Golgi protein 73 delayed hepatocyte proliferation of mouse in the early stages of liver regeneration

Signaling pathways of liver regeneration: Biological mechanisms and implications

The liver possesses a unique regenerative ability to restore its original mass, in this regard, partial hepatectomy (PHx) and partial liver transplantation (PLTx) can be executed smoothly and safely, which has important implications for the treatment of liver disease. Liver regeneration (LR) can be the very complicated procedure that involves multiple cytokines and transcription factors that interact with each other to activate different signaling pathways. Activation of these pathways can drive the LR process, which can be divided into three stages, namely, the initiation, progression, and termination stages. Therefore, it is important to investigate the pathways involved in LR to elucidate the mechanism of LR. This study reviews the latest research on the key signaling pathways in the different stages of LR.

GP73 blockade alleviates abnormal glucose homeostasis in diabetic mice

Golgi protein 73 (GP73), also called Golgi membrane protein 1 (GOLM1), is a resident Golgi type II transmembrane protein and is considered as a serum marker for the detection of a variety of cancers. A recent work revealed the role of the secreted GP73 in stimulating liver glucose production and systemic glucose homeostasis. Since exaggerated hepatic glucose production plays a key role in the pathogenesis of type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM), GP73 may thus represent a potential therapeutic target for treating diabetic patients with pathologically elevated levels. Here, in this study, we found that the circulating GP73 levels were significantly elevated in T2DM and positively correlated with hemoglobin A1c. Notably, the aberrantly upregulated GP73 levels were indispensable for the enhanced protein kinase A signaling pathway associated with diabetes. In diet-induced obese mouse model, GP73 siRNA primarily targeting liver tissue was potently effective in alleviating abnormal glucose metabolism. Ablation of GP73 from whole animals also exerted a profound glucose-lowering effect. Importantly, neutralizing circulating GP73 improved glucose metabolism in streptozotocin (STZ) and high-fat diet/STZ-induced diabetic mice. We thus concluded that GP73 was a feasible therapeutic target for the treatment of diabetes.

Possible roles of Golgi protein-73 in liver diseases

Golgi protein 73 (also known as GP73 or GOLPH2) is a transmembrane glycoprotein present in the Golgi apparatus. In diseased states, GP73 is expressed by hepatocytes rather than by bile duct epithelial cells. Many studies have reported that serum GP73 (sGP73) is a marker for hepatocellular carcinoma (HCC). For HCC diagnosis, the sensitivities of sGP73 were higher than that of other markers but the specificities were lower. Considering that the concentration of GP73 is consistent with the stage of liver fibrosis and cirrhosis, some studies have implied that GP73 may be a marker for liver fibrosis and cirrhosis. Increased sGP73 levels may result from hepatic inflammatory activity. During liver inflammation, GP73 facilitates liver tissue regeneration. By summarizing the studies on GP73 in liver diseases, we wish to focus on the mechanism of GP73 in diseases.