Effect of overexpression of inhibin alpha (1-32) fragment on bovine granulosa cell proliferation, apoptosis, steroidogenesis, and development of co-cultured oocytes.
The objective was to determine the effects of an inhibin alpha (1-32) fragment gene on proliferation, apoptosis, and steroidogenesis of bovine granulosa cells (GC) isolated from medium and small follicles (diameter >4-8 and 1-4mm, respectively), and the effect of GC, previously transfected with pEGISI, on oocyte maturation and in vitro embryo development. To enhance expression of the inhibin alpha (1-32) fragment, GC were transfected with pEGISI. Transfection inhibited (P<0.05) GC proliferation (88.8+/-2.1%; mean+/-S.E.M.) compared to the control and EGFP groups (100% and 97.5+/-2.1%) from medium follicles, with no significant effect on GC from small follicles. Apoptosis was higher (P<0.01) in transfected GC than in controls. Transfection increased (P<0.05) estradiol synthesis from both medium and small follicles (0.57+/-0.13 and 0.86+/-0.13 pg/mL vs. 0.19+/-0.05 and 0.35+/-0.09 pg/mL in controls) after culturing for 48 h, with suppression (P<0.05) in transfected GC after 96 h. Transfection reduced (P<0.05) progesterone synthesis in GC from both medium and small follicles (24.5+/-3.4 and 75.4+/-4.6 ng/mL vs. 45.42+/-5.33 and 117.32+/-11.99 ng/mL in controls) after culture for 48 h, with no significant difference after 96 h. Maturation rate of oocytes co-cultured with transfected GC from medium follicles was decreased relative to control (61.5+/-6.8% vs. 71.2+/-5.7%, P<0.05), with no significant effect on embryo development. In conclusion, overexpression of inhibin alpha (1-32) fragment regulated GC development; effects on subsequent oocyte maturation were both time- and stage-dependent.
Geng
Li-Ying
LY
Key Laboratory of Animal Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan 430070, PR China.
Fang
Ming
M
Yi
Jian-Ming
JM
Jiang
Fei
F
Moeen-ud-Din
Muhammad
M
Yang
Li-Guo
LG
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D002417:Cattle; D049109:Cell Proliferation; D002478:Cells, Cultured; D018920:Coculture Techniques; D047108:Embryonic Development / Q000502:physiology; D005260:Female; D015870:Gene Expression; D006107:Granulosa Cells / Q000166:cytology* / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D007265:Inhibins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D009865:Oocytes / Q000166:cytology / Q000502:physiology*; D013256:Steroids / Q000096:biosynthesis*; D014162:Transfection
D013256:Steroids; C094377:inhibin-alpha subunit; D049452:Green Fluorescent Proteins; D007265:Inhibins