The fatty acid binding protein 6 gene (<i>Fabp6</i>) is expressed in murine granulosa cells and is involved in ovulatory response to superstimulation

Abstract

The fatty acid binding protein 6 (Fabp6) is commonly regarded as a bile acid binding protein found in the distal portion of the small intestine and has been shown to be important in maintaining bile acid homeostasis. Previous studies have also reported the presence of Fabp6 in human, rat and fish ovaries, but the significance of Fabp6 in this organ is largely unknown. Therefore, we surveyed murine ovaries for Fabp6 gene expression and evaluated its role in ovarian function using mice with whole body Fabp6 deficiency. Here we show that the Fabp6 gene is expressed in granulosa and luteal cells of the mouse ovary. Treatment with gonadotropins stimulated Fabp6 gene expression in large antral follicles. The ovulation rate in response to superovulatory treatment in Fabp6-deficient mice was markedly decreased compared to wildtype (C57BL/6) mice. The results of this study suggest that expression of Fabp6 gene in granulosa cells serves an important and previously unrecognized function in fertility.

Evidence for the involvement of FXR signaling in ovarian granulosa cell function

“…Although the function of FABP6 is not fully elucidated, even in enterohepatic tissues, it may be possible that FABP6 has a role in transcellular shuttling of sex hormones in the ovary, as previous studies have demonstrated that FABP6 is involved in intracellular transport of bile acids in enterocytes [14, 37, 38]. In FABP6-deficient mice [39], the ovulation rate after superovulatory treatment was markedly decreased compared to that in wild-type mice, which suggests that FABP6 is involved in fertility via a function in granulosa cells.…”

Naturally-occurring carboxylic acids from traditional antidiabetic plants as potential pancreatic islet FABP3 inhibitors. A molecular docking–aided study

“…The main function of FABPs is to bind and transport fatty acids within cells with variable selectivity, a nities, and binding mechanisms [27,40]. Consequently, different FABP members [41][42][43][44][45][46][47][48] have a crucial role in lipid and energy metabolism of the entire body by regulating FA tra c in the cytoplasmic and nuclear compartments of different cell kinds. Studies with various transfected cell types overexpressing FABPs and with different cultured primary cell types from FABP knockout mice showed that FABPs enhance FAs uptake and incorporation into triglycerides and phospholipids.…”

Importance of fatty acid binding proteins in cellular function and organismal metabolism

“…26 Some types have widespread tissue distribution while others are restricted to one or a few tissues (Table S1). Selected examples include Fabp5 which appears to be the most widely distributed paralog of the Fabps in humans (Table S1), Fabp6 which resides in intestinal and ovarian tissues 27…”