ABSTRACT
Vitamin D reportedly plays an important role in the pathogenesis of diabetes mellitus; however, this role is unclear and debated. This study investigated the association between 25(OH) vitamin D, vitamin D-binding proteins, and vitamin D receptor (VDR) polymorphisms in healthy individuals and those with prediabetes and type 2 diabetes mellitus (T2D) from South Africa. A cross-sectional study was conducted involving subjects of mixed ancestry aged ≥20 years. Males presented with higher mean 25(OH) vitamin D levels than females, while females exhibited significantly higher serum vitamin D-binding protein levels. Significant differences in mean 25(OH) vitamin D levels were observed in normo-glycaemic, prediabetes, screen-detected DM, and known DM individuals. Vitamin D receptor SNPs Fok1 and Taq1 were not associated with glycaemic status. Fok1 was not associated with 25(OH) vitamin D deficiency, while Taq1 was associated with vitamin D insufficiency. This study showed a high prevalence of vitamin D deficiency/insufficiency in this South African population, with decreased vitamin D levels observed in hyperglycaemic individuals, which was not linked to either vitamin D-binding protein or polymorphisms in Fok1 of the VDR gene. These results may be used as a platform for further research into diagnosis and treatment of hyperglycaemia.
Subject(s)
Diabetes Mellitus, Type 2 , Hyperglycemia , Prediabetic State , Vitamin D Deficiency , Case-Control Studies , Cross-Sectional Studies , Diabetes Mellitus, Type 2/genetics , Female , Humans , Hyperglycemia/genetics , Male , Polymorphism, Single Nucleotide , Receptors, Calcitriol/genetics , Receptors, Calcitriol/metabolism , Vitamin D , Vitamin D Deficiency/genetics , Vitamin D-Binding Protein/genetics , VitaminsABSTRACT
Developing robust in vitro models of the liver is essential for studying the pathogenesis of liver diseases, hepatotoxicity testing, and regenerative medicine. Earlier studies were conducted using cell lines derived from hepatomas. Due to the inherent limitations of cell lines, researchers used primary human hepatocytes (PHHs), which are considered a gold standard for in vitro modeling of the liver. However, due to the high cost of PHHs and lack of donors, researchers have sought an alternative source for functional liver cells. Pluripotent stem cells (PSCs) emerged as a viable alternative due to their plasticity and high proliferative capacity. This review gives an overview of the major advances that have been achieved to develop protocols to generate liver cells such as hepatocytes, cholangiocytes, and Küpffer cells from PSCs. We also discuss their application in modeling the pathogenesis of liver diseases such as drug-induced liver injury, acute liver failure, and hepatic steatosis.
