Genistein Induces Adipogenic and Autophagic Effects in Rainbow Trout (Oncorhynchus mykiss) Adipose Tissue: In Vitro and In Vivo Models

Abstract

Soybeans are one of the most used alternative dietary ingredients in aquafeeds. However, they contain phytoestrogens like genistein (GE), which can have an impact on fish metabolism and health. This study aimed to investigate the in vitro and in vivo effects of GE on lipid metabolism, apoptosis, and autophagy in rainbow trout (Oncorhynchus mykiss). Primary cultured preadipocytes were incubated with GE at different concentrations, 10 or 100 μM, and 1 μM 17β-estradiol (E2). Furthermore, juveniles received an intraperitoneal injection of GE at 5 or 50 µg/g body weight, or E2 at 5 µg/g. In vitro, GE 100 μM increased lipid accumulation and reduced cell viability, apparently involving an autophagic process, indicated by the higher LC3-II protein levels, and higher lc3b and cathepsin d transcript levels achieved after GE 10 μM. In vivo, GE 50 µg/g upregulated the gene expression of fatty acid synthase (fas) and glyceraldehyde-3-phosphate dehydrogenase in adipose tissue, suggesting enhanced lipogenesis, whereas it increased hormone-sensitive lipase in liver, indicating a lipolytic response. Besides, autophagy-related genes increased in the tissues analyzed mainly after GE 50 µg/g treatment. Overall, these findings suggest that an elevated GE administration could lead to impaired adipocyte viability and lipid metabolism dysregulation in rainbow trout.

The obesogenic side of Genistein

“…In other words, lipids accumulated the most in the 100 μM GN-treated adipocytes. All these findings support that GN is an ED that is capable of causing obesity through interacting with the PPARγ protein ( 41 ). Similar results were reported by Grossini et al.…”

Effects of Genistein on Lipid Metabolism, Antioxidant Activity, and Immunity of Common Carp (Cyprinus carpio L.) Fed with High-Carbohydrate and High-Fat Diets

“…It is indicated that genistein at the concentration of 500 mg/kg supplementation in diet enhanced lipolysis in common carp. Genistein had the same effect on modulating hepatic lipid metabolism in rainbow trout [33,55]. Similarly, genistein has also been found to reduce hyperlipidemia and ameliorate a fatty liver, by reducing lipid deposition, improving lipid metabolism, and reducing liver steatosis in studies on mice [53,56,57].…”

“…Despite such beneficial effects, few studies have dealt with the function of dietary genistein with a high-energy diet in fish. In one of the studies, TG in serum of the genistein-injected group was remarkably downregulated in rainbow trout (Oncorhynchus mykiss) [33]. Our laboratory previously found that when low and medium doses of genistein (1 μM and 10 μM) are incubated with carp primary hepatocytes in vitro, the expression of lipid breakdown-related genes was enhanced [34].…”

Impact of Hydroxytyrosol-Rich Extract Supplementation in a High-Fat Diet on Gilthead Sea Bream (Sparus aurata) Lipid Metabolism

“…Finally, despite the limited availability of established fish cell lines, researchers have widely used in vitro models of primary cell cultures from different fish species for lipid metabolism studies in a more controlled environment [29,30,66]. In our study, the high dose of HT (100 µM) promoted an increase in the viability of adipocytes, irrespective of the diet.…”

“…To evaluate cell viability, the methylthiazolyldiphenyl-tetrazolium bromide (MTT) method was used, as previously reported elsewhere [29], in adipocyte samples from duplicate wells of 12-well plates. During the last 18 h of the total 72 h treatment, cells were incubated with a final concentration of 0.5 mg/mL of MTT (M5655, Sigma-Aldrich, Tres Cantos, Spain), washed with PBS, and resuspended in dimethyl sulfoxide for 3 h. Viability values were calculated from the absorbance readings at 570 nm, corrected at 650 nm, using a microplate reader (Tecan Infinite M200, Männedorf, Switzerland) (n = 4 independent cultures).…”