Spatiotemporal expression pattern of miR-205, miR-26a-5p, miR-17-5p, let-7b-5p, and their target genes during different stages of corpus luteum in Egyptian buffaloes.

BACKGROUND: No doubt that the corpus luteum (CL) plays a vital role in the regulation of female cyclicity in mammals. The scenarios among microRNAs (miRNAs) and their target genes and steroid hormones {estradiol (E2) and progesterone (P4)} are required for better understanding the molecular regulation of CL during its formation, maturation, and regression. We aimed to (I) study the changes in the relative abundance of miR-205, miR-26a-5p, miR-17-5p, and let-7b-5p and their target genes: LHCGR, CASP3, PCNA, AMH, and PLA2G3, during different stages of corpus luteum in Egyptian buffaloes, and (II) and to address different scenarios between steroid concentrations in the serum and the expression pattern of selected miRNAs and their targets. METHODS: The paired ovaries and blood samples were collected from apparently healthy 50 buffalo cows at a private abattoir. The ovaries bearing CL were macroscopically divided according to their morphological structure and color into hemorrhagic (CLH), developing (CLD), mature (CLM), regressed (CLR), and albicans (CLA). Small pieces from different stages of CL (CLH, CLD, CLM, CLR, and CLA) were cut and immediately kept at - 80 °C for total RNA isolation and qRT-PCR. The serum was separated for steroid level estimation. RESULTS: The LHCGR was expressed during different stages of CL, and the peak of expression was at the mid-luteal stage. The CASP3 revealed a stage-specific response at different stages of CL. The PCNA has an essential role in cellular proliferation in buffaloes CL. Both expression patterns of PLA2G3 and AMH were found over the various developmental and regression stages. It was noticed that miR-205 is conserved to target LHCGR and CASP3 transcripts. Moreover, CASP3 and AMH were targeted via miR-26a-5p. Additionally, the CASP3 and PLA2G3 were targeted via let-7b-5p. The P4 level reached its peak during CLM. There were positive and negative strong correlations between miRNAs (miR-26a-5p and miR-205), target genes (LHCGR and CASP3) during different stages of CL, and steroid hormones in the serum. CONCLUSIONS: Taken together, the orchestrated pattern among miRNAs, target genes, and steroid hormones is essential for maintaining the proper development and function of CL in buffalo cows.

Impact of nano-selenium on nuclear maturation and genes expression profile of buffalo oocytes matured in vitro.

Supplementation of maturation media with antioxidant (bulk form) improves oocyte maturation. However, the influence of adding antioxidant (nano-particles) on oocyte maturation is not well known. We aimed to evaluate the effect of selenium nano-particles (SeNP) and bulk selenium (Se) on buffalo oocytes maturation, in terms nuclear maturation and molecular level. Oocytes were distributed into four groups; 1st group was control, 2nd group was supplied with Se (10 ng/ml), 3rd and 4th groups were supplied with 1 µg/ml SeNP (67 nm), and SeNP (40 nm), respectively. Matured oocytes were fixed and stained to determine nuclear maturation. Oocytes and COC after IVM were stored at - 80 °C, for RNA isolation and qRT-PCR for selected genes. The Se and seNP (40 nm) had a positive effect on oocytes nuclear maturation rates. Apoptosis-related cysteine peptidase (CASP3) was reduced in all supplemented groups. Anti-Mullerian hormone (AMH) was up-regulated in oocytes supplemented with SeNP (40 nm). In COC, AMH increased in group supplemented with SeNP (67 nm). In oocytes, phospholipase A2 group III (PLA2G3) decreased in all supplemented groups. While in COC, PLA2G3increased in group supplied with Se. In COC, luteinizing hormone/choriogonadotropin receptor (LHCGR) increased in groups supplied with Se or SeNP (40 nm).Glutathione peroxidase 4 (GPX4) increased in all supplemented groups, in oocytes and COC. In oocytes, superoxide dismutase (SOD) was up-regulated in supplemented groups {Se and SeNP (67 nm)}.The DNA methyltransferase (DNMT) in oocytes was reduced in supplemented groups. In oocytes, the POU class 5 homeobox 1 (OCT4) increased in all supplemented groups. In COC, the OCT4 was over-expressed in group supplemented with SeNP (40 nm). Selenium supplementation in bulk or nano-particle improved in vitro buffalo oocytes maturation, viaup-regulation of antioxidant defense and development competence genes. SeNP (smaller size, 40 nm) induced higher expression of antioxidant gene.

Impact of pregnancy and nutrition on oxidant/antioxidant balance in sheep and goats reared in South Sinai, Egypt.

AIM: To monitor the effect of nutrition and pregnancy on oxidative status of animals under the arid condition of South Sinai. MATERIALS AND METHODS: Blood samples were taken from two groups of animals: The first group retained in farm and fed on concentrate (high diet) and another group grazing natural forage (low diet). Each group was subdivided into pregnant and non-pregnant animals. Blood samples were assayed for their content of malondialdehyde (MDA), total antioxidant capacity (TAC), catalase (CAT), and superoxide dismutase (SOD) enzymes. RESULTS: MDA level significantly increased in pregnant animals fed either concentrate or grazing low-quality forage and accompanied by a low level of TAC in pregnant grazing animals fed low-quality forage. The activity of CAT decreased in pregnant fed either concentrate or grazing and SOD significant decrease in the pregnant grazing group. These data suggested that the animals might have experienced some degree of oxidative stress and lipid peroxidation and indicating that redox homeostasis was impaired in those pregnant and specially fed on forage rations. CONCLUSION: Pregnancy constituted the most oxidative stress facing the grazing and concentrated diet feed sheep and goats under arid and saline conditions of Southern Sinai, Egypt.