Modulatory role of leptin on ovarian functions in water buffalo (Bubalus bubalis).

The aim of the present study was to demonstrate the modulatory role of leptin on bubaline granulosa cells (GCs) and luteal cells (LCs) functions using an in vitro cell culture system and to establish a cross talk between leptin and insulin-like growth factor-1 (IGF-1). GCs were collected from group IV follicles (>13 mm size) and LCs from mid-luteal phase corpus luteum and were grown in serum-containing media supplemented with leptin at three different dose rates (0.1, 1, and 10 ng/mL) and time durations (24, 48, and 72 hours). We evaluated the production and secretion of estradiol (E2) and progesterone (P4) using RIA and the mRNA expression of steroidogenic acute regulatory protein (STARD1), cytochrome P450 cholesterol side-chain cleavage (CYP11A1), 3ß-hydroxysteroid dehydrogenase (3ß-HSD), cytochrome P450 aromatase (CYP19A1), sterol regulatory element-binding protein 1 (SREBP1), steroidogenic factor-1 (SF1), anti-apoptotic gene PCNA, pro-apoptotic gene caspase 3 and endothelial cell marker, Von Willebrand factor (vWF), using quantitative real-time polymerase chain reaction. The results depicted a direct inhibitory action of leptin on GCs steroidogenesis in a time-dependent manner (P < 0.05), whereas in the presence of IGF-1 the inhibitory effect was reverted. Furthermore, leptin augmented both cellular proliferation (PCNA) and apoptosis (caspase 3). On the other hand, in LCs, leptin alone showed an apparent stimulatory effect on steroidogenesis (P < 0.05); however, in the presence of IGF-1, an antagonistic effect was witnessed. Moreover, leptin had an inhibitory effect on apoptosis while promoted cellular proliferation and angiogenesis. These findings were further strengthened by immunocytochemistry. To conclude, these observations for the first time reported that in buffaloes leptin has a direct dose-, time-, and tissue-dependent effect on ovarian steroidogenesis, angiogenesis, and cytoprotection, and furthermore, it can regulate the effect of systemic factors like IGF-1. Hence, this in vitro study provides an insight into the putative roles of leptin alone and its interactions in vivo.

Expression and localization of fibroblast growth factor (FGF) family in buffalo ovarian follicle during different stages of development and modulatory role of FGF2 on steroidogenesis and survival of cultured buffalo granulosa cells.

The present study investigated the expression and localization of FGF and its functional receptors in the follicle of buffalo and the treatment of FGF2 on mRNA expression of CYP19A1 (aromatase), PCNA, and BAX (BCL-2 associated X protein) in cultured buffalo granulosa cells (GCs). Follicles were classified into four groups based on size and E2 level in follicular fluid (FF): F1, 4-6mm diameter, E2<0.5ng/ml of FF; F2, 7-9mm, E2=0.5-5ng/ml; F3, 10-13mm, E2=5-40ng/ml; F4, >14mm, E2>180ng/ml. The qPCR studies revealed that the mRNA expression of FGF1, FGF2 and FGF7 were maximum (P<0.05) in theca interna (TI) whereas the transcripts of FGFR1, FGFR2, FGFR2IIIB and FGFR2IIIC were up-regulated (P<0.05) in GCs of F4 follicles. Protein expression of most members were maximum (P<0.05) in F4 follicles except FGFR3 and FGFR4. All members were localized in GC and TI with a stage specific immunoreactivity. Primary culture of GCs with treatment of FGF2 at different dose-time combinations revealed that the mRNA expression and immunoreactivity of CYP19A1 and PCNA were maximum (P<0.05) whereas BAX was minimum (P<0.05) with 200ng/ml at 72h of incubation. The findings indicate that FGF family members are expressed in a regulated manner in buffalo ovarian follicles during different stages of development where FGF2 may promote steroidogenesis and GC survival through autocrine and paracrine manner.

Expression and localization of angiopoietin family in buffalo ovarian follicles during different stages of development and modulatory role of angiopoietins on steroidogenesis and survival of cultured buffalo granulosa cells.

The present study investigated the expression and localization of angiopoietin (ANPT) family members in buffalo ovarian follicles of different size. It also looked at the role of ANPTs in estradiol secretion and mRNA expression of phosphoinositide-3-kinase-protein kinase B signaling pathway cellular proliferation (phosphoinositide-dependant kinase and protein kinase B [AKT]) and proapoptotic (BAD) factors with caspase 3 in cultured buffalo granulosa cells (GCs). The mRNA and protein expression of ANPT-1 was greatest (P < 0.05), whereas ANPT-2 was reduced (P < 0.05) in preovulatory follicles as compared to F1 follicle. Tyrosine kinase with immunoglobulin-like and EGF-like domains 1 transcripts and protein expression did not change in all follicular groups, whereas tyrosine kinase with immunoglobulin-like and EGF-like domains 2 mRNA was highest (P < 0.05) in theca interna but not GC layer of preovulatory follicle. All members of ANPT family were localized in GC and theca interna showing a stage specific immunoreactivity. Cultured GCs were treated with ANPT-1 and ANPT-2 separately at doses of 1, 10, and 100 ng/mL and in combination at 100 ng/mL for three incubation periods (24, 48, and 72 hours). Estradiol secretion was highest (P < 0.05) at 100 ng/mL at 72 hours of incubation when GCs were treated with either protein alone. The mRNA expression of phosphoinositide-dependant kinase and AKT was highest (P < 0.05), and BAD with caspase 3 was lowest (P < 0.05) at 100 ng/mL at 72 hours of incubation, when cultured GCs were treated separately with each protein or in combination. The immuoreactivity of AKT, pAKT, and pBAD were maximal, whereas BAD was minimal with 100 ng/mL at 72 hours when cultured GCs treated with either protein alone. The findings indicate that ANPTs are expressed in a regulated manner in buffalo ovarian follicle during different stages of development where they may promote steroidogenesis and GC survival through autocrine and paracrine actions.

Effect of thermal stress on expression profile of apoptosis related genes in peripheral blood mononuclear cells of transition Sahiwal cow.

The study was conducted to evaluate the effect of thermal stress on expression profile of genes related to apoptosis in peripartum Sahiwal cows. For this, twelve pregnant dry Sahiwal cows were selected from Livestock Research Centre at National Dairy Research Institute, Karnal. The cows were divided into two groups consisting of six Sahiwal cows each. Cows of group I calved during thermoneutral temperature conditions (THI=67.3) and cows of group II calved in summer season (THI=79.9). Blood samples were collected on -15, 0 and +15 days with respect to calving where day '0' represents the day of calving. The peripheral blood mononuclear cells (PBMC) were separated and total RNA was isolated for the BCL-2 (B-Cell Lymphoma-2), BAX (BCL-2 antagonist killer-1), BAK (Bcl-2-associated X protein), CASP-3 (cysteine-aspartic proteases-3) and P53 (tumour protien-53) mRNAs expression. It was found that there was up regulation of CASP-3 on the day of calving during both temperature conditions. Comparison between the two temperature conditions showed that expression of CASP-3, BCL-2, BAK, P53 and ratio of BAX/BCL-2 in PBMC increased during summer as compared to thermoneutral condition suggesting the susceptibility of these cells to apoptosis. Based on the above findings it can be concluded that during calving PBMC are more susceptible to apoptosis, and summer being more stressful potentiates the apoptosis of PBMC in Sahiwal cows.