Mouse Anti Human Rarres2 Hybridoma [DQUD-Sbssft3-3B6]

Background: In dairy cows, the energy cost of milk yield results in a negative energy balance (EB) and body fat mobilization that impairs reproductive efficiency. Emerging evidence suggests that the novel adipokines, Retinoic acid receptor responder protein 2 (RARRES2), and its main receptor, Chemokine-like receptor 1 (CMKLR1) are involved in the regulation of metabolic and ovarian functions. So, we investigated in a first experiment the plasma RARRES2, and RARRES2 and CMKLR1 mRNA expression levels in subcutaneous adipose tissue (SAT) and granulosa cells (GC) at different times of body fat mobilization in dairy cows (4, 8, 20 and 44weeks postpartum, wk. pp. for SAT and 8, 20 and 44 wk. pp. for GC). Then, in a second experiment we examined the effect of high (HE) and low energy (LE) diets on the RARRES2 system and its links with metabolic and reproductive parameters. Methods: The first experiment included 9 animals fed with HE diet from 4 to 44 wk. pp. and the second one included animals fed either a HE diet (n=8) or a LE diet (n=8) from - 4 to 16 wk. peripartum. In both experiments, various metabolic and reproductive parameters were determined and associated with plasma RARRES2 as measured by bovine ELISA. RARRES2 and CMKLR1 mRNA expression levels were analyzed by RT-qPCR in SAT after biopsy and GC after aspiration of follicles. Results: Plasma RARRES2 levels were higher at 4 wk. pp. as compared to 20 and 44 wk. pp. and they were positively correlated with body fat mobilization and milk yield. RARRES2 and CMKLR1 mRNA expression levels increased from 4 to 8 wk. pp. (fat mobilization, EB<0) and remained unchanged at 20 and 44 wk. pp. (fat reconstitution, EB >0) as compared to 4 wk. pp. in SAT. RARRES2 and CMKLR1 mRNA levels decreased from 8 to 44 wk. pp. in GC from small follicles. In the second experiment, plasma RARRES2 increased from - 4 to 8 wk. peripartum similarly in both LE and HE cows. In addition, the area under of plasma RARRES2 curve was highly negatively associated with the number of small follicles obtained in HE animals during the cycle before the first artificial insemination. In SAT of HE cows, RARRES2 mRNA expression decreased at 1 wk. pp. compared to - 4 and 16 wk. peripartum whereas opposite expression patterns were obtained for CMKLR1. Similar results were observed for CMKLR1 mRNA expression in LE cows while there was no variation in RARRES2 mRNA expression. Moreover, RARRES2 mRNA was higher expressed in LE than in HE cows at 1 wk. pp. Conclusions: The lactation-induced fat and energy mobilization influenced plasma RARRES2 profile and mRNA expression pattern of RARRES2 and CMKLR1 similarly in both SAT and GC. In addition, the energy content of the diet did not affect plasma RARRES2 but it altered RARRES2 mRNA expression in SAT and the area under the curve of plasma RARRES2 that was negatively associated to the number of small follicles in HE animals. Thus, RARRES2 could be a metabolic or ovarian signal involved in the interactions between metabolic and reproductive functions in dairy cows.

A key response of the myocardium to stress is the secretion of factors with paracrine or endocrine function. Intriguing in this respect is peptidase inhibitor 16 (PI16), a member of the CAP family of proteins which we found to be highly upregulated in cardiac disease. Up to this point, the mechanism of action and physiological function of PI16 remained elusive. Here, we show that PI16 is predominantly expressed by cardiac fibroblasts, which expose PI16 to the interstitium via a glycophosphatidylinositol (-GPI) membrane anchor. Based on a reported genetic association of PI16 and plasma levels of the chemokine chemerin, we investigated whether PI16 regulates post-translational processing of its precursor pro-chemerin. PI16-deficient mice were engineered and found to generate higher levels of processed chemerin than wildtype mice. Purified recombinant PI16 efficiently inhibited cathepsin K, a chemerin-activating protease, in vitro. Moreover, we show that conditioned medium from PI16-overexpressing cells impaired the activation of pro-chemerin. Together, our data indicate that PI16 suppresses chemerin activation in the myocardium and suggest that this circuit may be part of the cardiac stress response. (C) 2016 The Authors. Published by Elsevier Ltd.