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Les aclipocytokines (aclipo), produites par le tissu adipeux jouent un rôle clé dans la régulation des fonctions métaboliques mais qu'en est-il pour les fonctions de reproduction? Nous montrons que la chemerine et ses récepteurs, la visfatine et la résistine sont présents dans les cellules ovariennes humaines et bovines. ln vitro nous observons que la chemerine et la résistine diminuent la stéroïdogenèse des cellules de la granulosa (CG) humaine induite par IGF-1 alors que la visfatine l'augmente. Des résultats similaires sont observés chez la vache pour la chemerine et la visfatine. Dans les deux espèces, les aclipo influencent la prolifération des CG, et les voies de signalisation AKT, MAPK-ERKl/2 et P38 ou l'AMPK. Chez le bovin, la chemerine bloque la maturation ovocytaire in vitro. Nous observons aussi dans cette espèce que la concentration plasmatique de résistine et son expression dans les aclipocytes est augmentée après vêlage lorsque la lipomobilisation est élevée. Ces travaux confirment le rôle de la résistine dans la régulation métabolique chez la vache et montrent l'importance des adipo dans les cellules ovariennes humaine et bovine. Il reste à élargir leur rôle au niveau central dans les fonctions de reproduction.The aclipokines (aclipo ), produced by the adipose tissue play a key role in the regulation of metabolic functions, but what about for reproductive functions? We show that chemerin and its receptors, visfatin and resistin are present in human and bovine ovary cells. ln vitro we observe that chemerin and resistin decrease steroidogenesis in granulosa cells (GC) in response to IGF-1 while visfatin increases it. Similar results are observed for chemerin and visfatin in cows. In both species, chemerin, visfatin and resistin affect the proliferation of CG and signaling pathways inclucling AKT, MAPKERKl I 2 and P38 or AMPK. In cattle, chemerin blocks in vitro oocyte maturation. In this species, we also observe that the plasma resistin and its expression in aclipocytes are increased after calving when the fatty acid mobilization is high. This work confirms the role of resistin in the metabolic regulations in cow and shows the importance of aclipo in the human and bovine ovary cells. It remains to investigate their role at the central level in the reproductive functions

Expression of chemerin and its receptor, CMKLR1, in bovine ovary: A potential role in granulosa cell steroidogenesis and lipid metabolism

International audienc

La chémérine - Une adipocytokine pro-inflammatoire impliquée dans la fonction de reproduction ?

Chemerin is a pro-inflammatory adipokine secreted and expressed predominantly by adipocytes. Chemerin is initially involved in the regulation of the immune system, the adipogenesis and the energy metabolism. However, several recent studies show that this adipokine and its receptors are present in the gonads. In vitro, chemerin reduces steroidogenesis in ovarian and testicular cells in rodents and humans. Chemerin and its receptors are also present in the placenta. Chemerin plays an important role in the regulation of fetal and maternal metabolism, fetal growth and metabolic homeostasis during pregnancy. This review describes the role of chemerin in metabolism and reproduction.La chémérine est une adipocytokine pro-inflammatoire exprimée et sécrétée majoritairement par les adipocytes. Elle a été initialement impliquée dans la régulation du système immunitaire, de l’adipogenèse et du métabolisme énergétique. Cependant, plusieurs études récentes montrent que cette adipocytokine et ses récepteurs sont exprimés au niveau des gonades. In vitro, elle diminue la stéroïdogenèse des cellules ovariennes et testiculaires de rongeurs et d’humains. La chémérine et ses récepteurs sont aussi présents au niveau du placenta. Ils y jouent un rôle important dans la régulation du métabolisme fœto-maternel, de la croissance du fœtus et de l’homéostasie métabolique pendant la grossesse

Expression et rôle de la chemerine et de son récepteur CMKLR1 dans les cellules de la granulosa bovine

National audienc

Caractérisation et effet de la vistafine dans les fonctions ovariennes bovines

National audienc

Poultry and Pig Low-input and Organic production systems’ Welfare

National audienc

Adipokines and the female reproductive tract

It is well known that adipose tissue can influence puberty, sexual maturation, and fertility in different species. Adipose tissue secretes molecules called adipokines which most likely have an endocrine effect on reproductive function. It has been revealed over the last few years that adipokines are functionally implicated at all levels of the reproductive axis including the gonad and hypothalamicpituitary axis. Many studies have shown the presence and the role of the adipokines and their receptors in the female reproductive tract of different species. These adipokines regulate ovarian steroidogenesis, oocyte maturation, and embryo development. They are also present in the uterus and placenta where they could create a favorable environment for embryonic implantation and play a key role in maternal-fetal metabolism communication and gestation. Reproductive functions are strongly dependent on energy balance, and thereby metabolic abnormalities can lead to the development of some pathophysiologies such as polycystic ovary syndrome (PCOS). Adipokines could be a link between reproduction and energy metabolism and could partly explain some infertility related to obesity or PCOS

Nutritional signals and reproduction

There is extensive evidence that nutrition influences reproductive function in various mammalian species (agricultural animals, rodents and human). However, the mechanisms underlying the relationship between nutrition, energy metabolism and reproductive function are poorly understood. This review considers nutrient sensors as a molecular link between food molecules and consequences for female and male fertility. It focuses on the roles and the molecular mechanisms of some of the relevant hormones, such as insulin and adipokines, and of energy substrates (glucose, fatty acids and amino acids), in the gonadotropic axis (central nervous system and gonads). A greater understanding of the interactions between nutrition and fertility is required for both better management of the physiological processes and the development of new molecules to prevent or cure metabolic diseases and their consequences for fertility