Expression and localization of angiopoietin family in corpus luteum during different stages of oestrous cycle and modulatory role of angiopoietins on steroidogenesis, angiogenesis and survivability of cultured buffalo luteal cells

Abstract

The objective of this study was to document the expression and localization of angiopoietin (ANGPT) family members comprising of angiopoietin (ANGPT1 and ANGPT2), and their receptors (Tie1 and Tie2) in buffalo corpus luteum (CL) obtained from different stages of the oestrous cycle, and the modulatory role of ANGPT1 and ANGPT2 alone or in combinations on progesterone (P ) secretion and mRNA expression of phosphotidylinositide-3kinase-protein kinase B (PI3K-AKT), phosphoinositide-dependent kinase (PDK), protein kinase B (AKT), Bcl2 associated death promoter (BAD), caspase 3 and von willebrand factor (vWF) in luteal cells obtained from midluteal phase (MLP) of oestrous cycle in buffalo. Real-time RT-PCR (qPCR), Western blot and immunohistochemistry were applied to investigate mRNA expression, protein expression and localization of examined factors whereas, the P secretion was assessed by RIA. The mRNA and protein expression of ANGPT1 and Tie2 was maximum (p < .05) in mid luteal phase (MLP) of oestrous cycle. The ANGPT2 mRNA and protein expression was maximum (p < .05) in early luteal phase, decreased in MLP and again increased in late luteal phase of oestrous cycle. ANGPT family members were localized in luteal cells and endothelial cells with a stage specific immunoreactivity. P secretion was highest (p < .05) with 100 ng/ml at 72 hr when luteal cells were treated with either protein alone. The mRNA expression of PDK, AKT and vWF was highest (p < .05) and BAD along with caspase 3 were lowest (p < .05) at 100 ng/ml at 72 hr of incubation period, when cultured luteal cells were treated with either protein alone or in combination. To conclude, our study explores the steroidogenic potential of angiopoietins to promote P secretion, luteal cell survival and angiogenesis through an autocrine and paracrine actions in buffalo CL.

mRNA and miRNA Transcriptome Profiling of Granulosa and Theca Layers From Geese Ovarian Follicles Reveals the Crucial Pathways and Interaction Networks for Regulation of Follicle Selection

“…SRPX2 reportedly acts as a regulator of angiogenesis (Marijana et al, 2009); NDNF functions as a modulator that enhances endothelial cell function and revascularization processes (Koji et al, 2014); THBS1 mediates IGF-I-induced steroidogenesis and proliferation in cultured porcine granulosa cells (Grado-Ahuir et al, 2009), inhibits angiogenesis, and promotes follicular atresia in rats (Garside et al, 2010); the FGF / FGF receptor contributes to tumor vascularization and adult angiogenesis (Presta et al, 2005); and lysophosphatidic acid plays a role in angiogenesis and enhances the angiogenic capability by the LPA1/3 receptor (Chen et al, 2019). Follicular steroidogenesis and survivability primarily depend on ovarian blood supply, and in mammals, vascularization has been reported to be an essential step in the modulation of follicle and corpus luteum development and function (Young and McNeilly, 2010; Berisha et al, 2016; Mishra et al, 2016). In summary, based on existing research results, changes in expression level of SRPX2 , NDNF , THBS1 , FGF13 , AGTR2 , and LPAR3 in the theca layer during follicular selection may be important for a concurrent regulation in vasculature following follicular selection.…”

Expression of Angiopoietin 2 in ovarian follicles of crossbred Malabari goat

“…It is worth mentioning that the role of angiopoietins 1 and 2 on ovarian follicular angiogenesis is found to be influenced by the ratio between the two factors as well as the levels of VEGF (Fraser., 2006). By means of their angiogenic activity, Ang-Tie system is observed to be actively involved in the regulation of ovarian follicular dynamics encompassing all the growth and developmental stages of folliculogenesis till ovulation in various species as rats (Maisonpierre et al, 1997), cow (Hayashi et al, 2003, Shimizu et al, 2007, ewes (Chowdhury et al, 2010, Christensen et al, 2014, buffalo (Mishra et al, 2016a), monkey (Hazzard et al, 1999), human (Nishigaki et al 2011), gilts (Shimizu et al, 2003) etc. Though the expression studies on various local ovarian angiogenic factors are plenty in most species of domestic animals, there is a noticeable paucity of research attempts in this direction in caprine.…”

Transcriptional Regulation of Thrombospondins and Its Functional Validation through CRISPR/Cas9 Mediated Gene Editing in Corpus Luteum of Water Buffalo (Bubalus Bubalis)

“…Ovaries were collected in 1X PBS at 37°C in a vacuum flask from a local abattoir. In all of the experiments, only late luteal stage (days 11-16) was used which were selected based on the established criteria applied previously in buffalo [6]. The luteal cell culture was developed using the protocol established in our laboratory [14].…”

“…The stringency in the process of ovarian angiogenesis is modulated by various pro and anti-angiogenic factors. Several pro-angiogenic factors are well-known; however, those that seem to be the most important in ovarian angiogenesis are FGF2, VEGF and ANG II [4][5][6]. On the contrary, a number of naturally occurring inhibitors of angiogenesis have been identified in mammalian tissues which have been considered to maintain quiescence of the normal vasculature.…”