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In animals, obesity caused by consumption of a sweet-fat diet (SFD) is the most adequate mouse model of human diet-induced obesity. Fibroblast growth factor 21 (FGF21) reduces body weight, beneficially affects taste preferences, and corrects glucose metabolism in obese mice. Sex is known to influence FGF21 effects in different models of diet-induced and hereditary obesity. In mice with SFD-induced obesity, the effects of FGF21 have been studied only in males. The aim of this study was to compare the effects of FGF21 on body weight, food preferences and glucose and lipid metabolism in C57Bl/6J male and female mice with SFD-induced obesity. Mice were fed with a diet consisting of standard chow, lard and cookies for 10 weeks, then they were injected with FGF21 (1 mg per 1 kg) or vehicle for 7 days. Body weight, weights of different types of food, blood parameters, glucose tolerance, gene and protein expression in the liver, gene expression in the white, brown adipose tissues, and the hypothalamus were assessed. FGF21 administration reduced body weight, did not alter total energy consumption, and activated orexigenic pathways of hypothalamus in mice of both sexes. However, sex dimorphism was found in the realization of the orexigenic FGF21 action at the transcriptional level in the hypothalamus. Metabolic effects of FGF21 were also sex-specific. Only in males, FGF21 exerted beneficial antidiabetic action: it reduced fatty acid and leptin plasma levels, improved glucose-tolerance, and upregulated hepatic expression of Ppargc1, Fasn, Accα, involved in lipid turnover, gene Insr and protein glucokinase, involved in insulin action. Only in obese females, FGF21 induced preference of standard diet to sweet food. Thus, in mouse model of obesity induced by consumption of a sweet-fat diet, the catabolic effect of FGF21 was not sex-specific and hormonal, transcriptional and behavioral effects of FGF21 were sex-specific. These data suggest elaboration of different approaches to use FGF21 analogs for correction of metabolic consequences of obesity in different sexes.

The f ibroblast growth factor 21 (FGF21) synthesized in the liver, acting as a hormone, increases insulin sensitivity and energy expenditure. FGF21 administration has potent benef icial effects on obesity and diabetes in humans, cynomolgus monkey, and rodents. The therapeutic effects of FGF21 have been studied mainly in males. They are not always manifested in females, and they are accompanied by sex-specif ic activation of gene expression in tissues. We have suggested that one of the causes of sexual dimorphism in response to FGF21 is the effect of estradiol (E2). Currently, it is not known how estradiol modif ies the pharmacological effects of FGF21. The objective of this study was to study the inf luence of FGF21 on metabolic characteristics, food intake, and the expression of carbohydrate and fat metabolism genes in the liver, adipose tissue, and hypothalamus in female mice with alimentary obesity and low (ovariectomy) or high (ovariectomy + E2) blood estradiol level. In ovariectomized (OVX) females, the development of obesity was induced by the consumption of a high sweet-fat diet (standard chow, lard, and cookies) for 8 weeks. We investigated the effects of FGF21 on body weight, blood levels, food preferences and gene expression in tissues when FGF21 was administered separately or in combination with E2 for 13 days. In OVX obese females, FGF21, regardless of E2-treatment, did not affect body weight, and adipose tissue weight, or glucose tolerance but increased the consumption of standard chow, reduced blood glucose levels, and suppressed its own expression in the liver (Fgf21), as well as the expression of the G6pc and Acacα genes. This study is the f irst to show the modif ication of FGF21 effects by estradiol: inhibition of FGF21-inf luence on the expression of Irs2 and Pklr in the liver and potentiation of the FGF21-stimulated expression of Lepr and Klb in the hypothalamus. In addition, when administered together with estradiol, FGF21 exerted an inhibitory effect on the expression of Cpt1α in subcutaneous white adipose tissue (scWAT), whereas no stimulating FGF21 effects on the expression of Insr and Acacβ in scWAT or inhibitory FGF21 effect on the plasma insulin level were observed. The results suggest that the absence of FGF21 effects on body and adipose tissue weights in OVX obese females and its benef icial effect on food intake and blood glucose levels are not associated with the action of estradiol. However, estradiol affects the transcriptional effects of FGF21 in the liver, white adipose tissue, and hypothalamus, which may underlie sex differences in the FGF21 effect on the expression of metabolic genes and, possibly, in pharmacological FGF21 effects.

Reduced insulin sensitivity plays an important role in the pathogenesis of type II diabetes. There are sex differences in the development of metabolic disorders. The aim of this work was to investigate the insulin signal transduction gene expression in mice of different sex and age. Male and female C57BL/6J mice were used in our studies. Gene expression was assayed by RT-PCR. It was shown that insulin sensitivity in females was higher than in males regardless of age because the level of glucose in blood plasma of females does not differ from that in males, whereas female insulin levels were lower than male insulin levels. Female glucose tolerance increased with age, and glucose tolerance was higher in females than in males at the age of 30 weeks. It was shown that sex and age affect the expressions of insulin signal transduction genes. It was shown that there are sex differences in the levels of mRNA Pik3cd in the liver, in the levels of mRNA Irs1 in the muscle, in the levels of mRNA Irs1 and Slc2a4 in adipose tissue at the age of 10 weeks, and there are sex differences in the levels of mRNA Irs2 and Pik3cd in the liver, in the levels mRNA Pik3cd and Slc2a4 in the muscle, in the levels mRNA Insr and Pik3cd in adipose tissue at the age of 30 weeks. In young animals, the expression of the genes was higher in females than in males in all tissues. In adult animals, the expression of the genes in the liver was higher in females than in males, the expression of the genes in muscle and adipose tissues were lower in females than in males. In males, the levels of mRNA Insr in the liver and muscles and mRNA Pik3cd in adipose tissue decreased with age, and the level of mRNA Pik3cd in muscles increased with age. In females, the levels of mRNA Irs1 in muscle and mRNA Pik3cd and Slc2a4 in adipose tissue decreased with age. Thus the molecular basis of sex differences and age-related changes in insulin sensitivity may be a change in expressions of insulin signal transduction genes in the target tissues.

Autoinflammatory diseases (AIDs) are a group of rare disorders characterized by persistent or recurrent inflammation caused by the hyperactivation of mediators and innate immune cells (neutrophils, monocytes/macrophages). The paper describes the authors' own case of NLRP12-associated AIDs and the efficiency of canakinumab therapy and reviews a series of cases of the similar disease, which are given in the literature.