Obesity leads to higher risk of sperm DNA damage in infertile patients

There has been a growing interest over the past few years in the impact of male nutrition on fertility. Infertility has been linked to male overweight or obesity, and conventional semen parameter values seem to be altered in case of high body mass index （BMI）. A few studies assessing the impact of BMI on sperm DNA integrity have been published, but they did not lead to a strong consensus. Our objective was to explore further the relationship between sperm DNA integrity and BMI, through a 3-year multicentre study. Three hundred and thirty male partners in subfertile couples were included. Using the terminal uridine nick-end labelling （TUNEL） assay, we observed an increased rate of sDerm DNA damage in obese men （odds ratio （95% confidence interval）： 2.5 （1.2-5.1））.

Body mass index is not associated with sperm-zona pellucida binding ability in subfertile males

Lifestyle factors, such as weight and nutritional status may affect male fertility, including sperm fertilization ability. The objective of this retrospective study was to evaluate the association between body mass index （BMI） and sperm-zona pellucida binding ability assessed according to the zona binding （ZB） test, which has been described to be a relevant diagnostic tool for the prediction of in vitro fertilization （IVF） ability. Three hundred and six male patients from couples diagnosed with primary idiopathic or mild male factor infertility were included. Correlations between BMI and semen parameters according to ZB test indices were assessed, together with frequencies of positive and negative tests across the BMI categories. In this selected population, BMI was not related to conventional semen parameters or sperm quality assessed according to the ability of spermatozoa to bind to the zona pellucida. The previously described poor outcomes of IVF procedures in cases of male obesity could be due to other sperm defects, such as alterations of sperm capacitation or acrosome reaction. The link between male BMI and biological outcomes during IVF procedures, such as fertilization rates, should be further evaluated.

High Plasma Concentrations of Sclerostin, an Inhibitor of the Wnt Signaling Pathway, in Young Horses Affected by Osteochondrosis

Osteochondrosis (OC) is a developmental disease in horses with a significant impact on the horse’s welfare and performance. The early disturbance of enchondral ossification progresses to inflammatory and healing process in older horses. Metabolic pathway analysis showed an obvious dysregulation of several signaling pathways related to cartilage formation and cartilage repair such as Wnt/β-catenin, Indian hedgehog and TGF-β signaling pathways. Other regulated genes appeared to be involved in high carbohydrate diet, abnormal insulin metabolism or inflammation. Sclerostin is an osteocyte-secreted soluble antagonist of the Wnt/β-catenin signaling pathway. It is crucial for osteoblast development and activity and is increased in naturally occurring lesions of equine osteochondrosis. The aim of this study is to compare the circulating sclerostin levels between OC-affected (n = 20) and healthy horses (n = 19). A significant linear regression between plasma sclerostin and age is observed especially in the healthy young horses. The mean plasma sclerostin concentration is significantly higher in young horses suffering from osteochondrosis compared to the control horses. These results reinforce the possible role of the Wnt/β-catenin signaling pathway in the OC pathogeny. The inhibition of this essential pathway could disturb the osteo-chondral differentiation. More studies are currently needed to define the eventual clinic interest of plasma sclerostin as future biomarker in bone and cartilage diseases.