Age-related changes in transcriptional abundance and circulating levels of anti-Mullerian hormone and Sertoli cell count in crossbred and Zebu bovine males.

Age-related changes in peripheral anti-Mullerian hormone (AMH) concentrations and transcriptional abundance of AMH gene in testicular tissue were studied in crossbred (Holstein Friesian × Tharparkar) and Zebu (Tharparkar) males. In both the breeds, basal AMH concentrations were estimated using ELISA method in blood plasma obtained from six males each at 1, 6, 12, 18, and 24 months age. After blood collection at respective ages, all the males were castrated and expression and immunolocalization of AMH was performed in the testicular tissue. The concentration of AMH in blood plasma was found to be highest at 1 month of age in both crossbred and Zebu males, which subsequently decreased with advancing age. Significantly (P < 0.05) lower concentration of AMH was observed in crossbred as compared with Zebu males at 24 months of age. In line with peripheral AMH concentrations, the expression of AMH gene was also higher (P < 0.05) at 1 month of age, which thereafter declined significantly with advancement of age in crossbred males. Furthermore, the expression of AMH gene differed significantly between Zebu and crossbred males at all the age groups studied. Immunolocalization of AMH in testicular tissue also revealed a stronger expression at 1 month age, which gradually decreased till 24 months of age. The true Sertoli cell count was significantly higher in Zebu compared with crossbred males at all age groups studied except at 6 months age. The relationship between Sertoli cell count and circulating AMH concentrations was negative and significant (r = -0.81; P = 0.004). In conclusion, expression of AMH gene in testicular tissue and peripheral blood concentrations of AMH were higher in young compared with adults in both crossbred and Zebu males; however, the transcriptional abundance and circulating levels of AMH were higher in Zebu compared with crossbred males.

Transcriptional abundance of antioxidant enzymes in endometrium and their circulating levels in Zebu cows with and without uterine infection.

Oxidative stress during peripartum period may compromise the uterine immunity. In the present study, we assessed the oxidative stress and antioxidant status during peripartum period and studied their relationship with postpartum uterine infection in dairy cows. Peripheral blood concentrations of total antioxidant capacity (TAC), malondialdehyde (MDA) and nitric oxide (NO) were determined (day -21, -7, on the day of calving and day +7, +21, +35) in normal (n=11), puerperal metritic (n=7) and clinical endometritic (n=6) cows. Endometrial biopsy was performed on the day of calving and expression of CAT, GPx4 and SOD2 genes was studied using qRT-PCR. Puerperal metritic cows had significantly (P<0.05) lower TAC (on day -7, day 0, day +7, +21 & +35), higher MDA (on day -21, -7 & on the day of calving) and NO (on day 0, +7 & day +35) concentrations compared to normal cows. Similarly, clinical endometritic cows had significantly (P<0.05) lower TAC (on day -7, 0, +7 & +21), higher MDA (on day -21, -7, +7 and +35) and NO (on day +7, +21 & +35) concentrations compared to normal cows. The expression of CAT and GPx4 genes was lower (P<0.05) and SOD2 gene was higher (P<0.05) in endometrial tissue of cows that developed uterine infection compared to normal cows. The relationship of peripheral levels of MDA and NO with antioxidant enzymes expression in endometrial tissue was found significant. Receiver operator characteristic analysis revealed that the concentrations of TAC on day -7 to day +35, MDA on day -21 to day +7 and NO on the day of calving to day +35 were highly correlated to the development of postpartum uterine infection in cows. It may be inferred that the low serum TAC level and high level of lipid peroxidation and NO during peripartum period influenced the endometrial expression of anitioxidative genes that compromised the uterine health during postpartum period.

Cellular and molecular mechanisms involved in placental separation in the bovine: A review.

Retention of fetal membranes (RFM), where the fetal placenta is not expelled within 8-12 hr after calving, lowers bovine productivity and fertility, resulting in significant economic loss to the dairy industry. Several risk factors that predispose an individual to RFM are known, but a unifying pathogenesis remains elusive due to its multifactorial etiology. Fetal membrane separation and expulsion after parturition involves structural and immunological changes of the bovine placentome that are governed predominantly by steroid hormones and the prostaglandin milieu of late pregnancy and parturition. Maturation of the placentome, a gradual and concerted event of late gestation, is likely initiated by the up-regulation of fetal major histocompatibility complex class I in the interplacentomal region-which increases the apoptosis of binucleate and other trophoblastic cells, the degradation of collagen in the extracellular matrix by matrix metalloproteinases, and an influx of phagocytic leukocytes. Shear force further distorts the crypt architecture of the mature placentomes when they are forced against the fetus during the second stage of labor. Cotyledon dehiscence from the caruncular crypts is completed following fetal expulsion as a result of acute shrinkage of the cotelydonary villi as well as reduced perfusion to the caruncle; the secundinae is expelled by uterine contractions. A better understanding of placentomal maturation, intra-partum, and immediate postpartum changes of the placentome should help develop strategies for the treatment and prevention of RFM. The present review proposes a model of placentome maturation and separation of fetal membranes in the dairy cow.

Expression of short chain fatty acid receptors and pro-inflammatory cytokines in utero-placental tissues is altered in cows developing retention of fetal membranes.

INTRODUCTION: Retention of fetal membranes (RFM) is an economically important condition in dairy cattle disturbing the health and production in affected animals. In spite of extensive research, pathogenesis for RFM and identification of a predictive marker for the condition still remains elusive. Since expulsion of fetal membranes in an inflammatory process, studying the expression of inflammatory molecules is expected to give an idea about the pathogenesis of RFM. METHODS: Expression of pro-inflammatory cytokines, short chain fatty acid (SCFA) receptors and adhesion molecules was studied using qRT-PCR in the utero-placental tissues obtained from the cows that expelled fetal membranes normally (n = 12) and from the cows that developed RFM (n = 12). Concentrations of SCFAs were estimated in the utero-placental tissues using Gas Chromatography. RESULTS: The concentration of butyrate in the utero-placental tissue extract was 3-4 times lower, and GPR41 and GPR43 mRNA expression was 7.7-10.0 and 3.4-4.4 folds lower (p < 0.05) in cows that developed RFM compared to those that expelled the fetal membranes normally. The expression of IL-1, IL-6, IL-8, TNF-α, ICAM and PECAM was higher (p < 0.05) in the cows that normally expelled the fetal membranes compared to those that developed RFM. DISCUSSION: Since a clear association of butyrate levels, expression of pro-inflammatory cytokines, adhesion molecules and SCFAs receptors was observed with expulsion of fetal membranes, modulating the levels of these molecules prior to parturition might help in reducing the incidence of RFM in cows. CONCLUSION: Inflammatory response is essential for normal expulsion of fetal membranes and that inadequate or altered expression of pro-inflammatory cytokines, adhesion molecules and SCFA receptors is associated with RFM in cows.