Limits...
Gene expression profiling of preovulatory follicle in the buffalo cow: effects of increased IGF-I concentration on periovulatory events.

Rao JU, Shah KB, Puttaiah J, Rudraiah M - PLoS ONE (2011)

Bottom Line: Thus, further experiments were conducted to verify the effects of increased intrafollicular IGF-I levels on the expression of genes associated with the above mentioned processes.The results indicated that increased intrafollicular concentrations of IGF-I caused changes in expression of genes associated with steroidogenesis (StAR, SRF) and apoptosis (BCL-2, FKHR, PAWR).These results taken together suggest that onset of gonadotropin surge triggers activation of various biological pathways and that the effects of growth factors and peptides on gonadotropin actions could be examined during preovulatory follicle development.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, India.

ABSTRACT
The preovulatory follicle in response to gonadotropin surge undergoes dramatic biochemical, and morphological changes orchestrated by expression changes in hundreds of genes. Employing well characterized bovine preovulatory follicle model, granulosa cells (GCs) and follicle wall were collected from the preovulatory follicle before, 1, 10 and 22 h post peak LH surge. Microarray analysis performed on GCs revealed that 450 and 111 genes were differentially expressed at 1 and 22 h post peak LH surge, respectively. For validation, qPCR and immunocytochemistry analyses were carried out for some of the differentially expressed genes. Expression analysis of many of these genes showed distinct expression patterns in GCs and the follicle wall. To study molecular functions and genetic networks, microarray data was analyzed using Ingenuity Pathway Analysis which revealed majority of the differentially expressed genes to cluster within processes like steroidogenesis, cell survival and cell differentiation. In the ovarian follicle, IGF-I is established to be an important regulator of the above mentioned molecular functions. Thus, further experiments were conducted to verify the effects of increased intrafollicular IGF-I levels on the expression of genes associated with the above mentioned processes. For this purpose, buffalo cows were administered with exogenous bGH to transiently increase circulating and intrafollicular concentrations of IGF-I. The results indicated that increased intrafollicular concentrations of IGF-I caused changes in expression of genes associated with steroidogenesis (StAR, SRF) and apoptosis (BCL-2, FKHR, PAWR). These results taken together suggest that onset of gonadotropin surge triggers activation of various biological pathways and that the effects of growth factors and peptides on gonadotropin actions could be examined during preovulatory follicle development.

Show MeSH
Gene expression changes in the preovulatory follicle of animals receiving bGH treatment.The qPCR fold change in expression pattern of selected genes associated with of IGF-I signaling (IGF-IR and PAPPA), luteinization (Oxytocin and StAR), cell survival, proliferation and differentiation (BCL-2, FKHR, PAWR, RASA1 and SRF) in granulosa cells of follicles retrieved before (green) and 22 h post peak LH surge of Veh (blue) or bGH (orange) treated animals. Bars with different alphabets above them are significantly different (p<0.05).
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3119055&req=5

pone-0020754-g009: Gene expression changes in the preovulatory follicle of animals receiving bGH treatment.The qPCR fold change in expression pattern of selected genes associated with of IGF-I signaling (IGF-IR and PAPPA), luteinization (Oxytocin and StAR), cell survival, proliferation and differentiation (BCL-2, FKHR, PAWR, RASA1 and SRF) in granulosa cells of follicles retrieved before (green) and 22 h post peak LH surge of Veh (blue) or bGH (orange) treated animals. Bars with different alphabets above them are significantly different (p<0.05).

Mentions: After having established the elevated IGF-I levels both in circulation and in follicular fluid, and possibly presence of more biologically active form, effects of IGF-I on expression changes of few of the genes associated with IGF-I signaling, luteinization process, tissue remodeling as well as apoptosis were examined and the results were presented in Fig. 9. Expression of IGF-IR in GCs of bGH treated animals was significantly lower at 22 h post peak LH surge (Fig. 9). Expression of PAPPA was low at 22 h post peak LH surge in GCs of both Veh and bGH treated animals. Expression of StAR and oxytocin, regarded as marker of luteinization and ovulation increased several fold at 22 h post peak LH surge, and the expression was significantly (p<0.05) higher in GCs of bGH treated animals (Fig. 9). Expression of transcription factors, FKHR and SRF, was significantly (p<0.05) higher in GCs of bGH treated animals at 22 h post peak LH surge (Fig. 9). Expression of BCl-2, PAWR and RASA-1 genes associated with apoptotic processes showed significantly higher expression in bGH treated animals compared to Veh treated animals (p<0.05; Fig. 9).


Gene expression profiling of preovulatory follicle in the buffalo cow: effects of increased IGF-I concentration on periovulatory events.

Rao JU, Shah KB, Puttaiah J, Rudraiah M - PLoS ONE (2011)

Gene expression changes in the preovulatory follicle of animals receiving bGH treatment.The qPCR fold change in expression pattern of selected genes associated with of IGF-I signaling (IGF-IR and PAPPA), luteinization (Oxytocin and StAR), cell survival, proliferation and differentiation (BCL-2, FKHR, PAWR, RASA1 and SRF) in granulosa cells of follicles retrieved before (green) and 22 h post peak LH surge of Veh (blue) or bGH (orange) treated animals. Bars with different alphabets above them are significantly different (p<0.05).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3119055&req=5

pone-0020754-g009: Gene expression changes in the preovulatory follicle of animals receiving bGH treatment.The qPCR fold change in expression pattern of selected genes associated with of IGF-I signaling (IGF-IR and PAPPA), luteinization (Oxytocin and StAR), cell survival, proliferation and differentiation (BCL-2, FKHR, PAWR, RASA1 and SRF) in granulosa cells of follicles retrieved before (green) and 22 h post peak LH surge of Veh (blue) or bGH (orange) treated animals. Bars with different alphabets above them are significantly different (p<0.05).
Mentions: After having established the elevated IGF-I levels both in circulation and in follicular fluid, and possibly presence of more biologically active form, effects of IGF-I on expression changes of few of the genes associated with IGF-I signaling, luteinization process, tissue remodeling as well as apoptosis were examined and the results were presented in Fig. 9. Expression of IGF-IR in GCs of bGH treated animals was significantly lower at 22 h post peak LH surge (Fig. 9). Expression of PAPPA was low at 22 h post peak LH surge in GCs of both Veh and bGH treated animals. Expression of StAR and oxytocin, regarded as marker of luteinization and ovulation increased several fold at 22 h post peak LH surge, and the expression was significantly (p<0.05) higher in GCs of bGH treated animals (Fig. 9). Expression of transcription factors, FKHR and SRF, was significantly (p<0.05) higher in GCs of bGH treated animals at 22 h post peak LH surge (Fig. 9). Expression of BCl-2, PAWR and RASA-1 genes associated with apoptotic processes showed significantly higher expression in bGH treated animals compared to Veh treated animals (p<0.05; Fig. 9).

Bottom Line: Thus, further experiments were conducted to verify the effects of increased intrafollicular IGF-I levels on the expression of genes associated with the above mentioned processes.The results indicated that increased intrafollicular concentrations of IGF-I caused changes in expression of genes associated with steroidogenesis (StAR, SRF) and apoptosis (BCL-2, FKHR, PAWR).These results taken together suggest that onset of gonadotropin surge triggers activation of various biological pathways and that the effects of growth factors and peptides on gonadotropin actions could be examined during preovulatory follicle development.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, India.

ABSTRACT
The preovulatory follicle in response to gonadotropin surge undergoes dramatic biochemical, and morphological changes orchestrated by expression changes in hundreds of genes. Employing well characterized bovine preovulatory follicle model, granulosa cells (GCs) and follicle wall were collected from the preovulatory follicle before, 1, 10 and 22 h post peak LH surge. Microarray analysis performed on GCs revealed that 450 and 111 genes were differentially expressed at 1 and 22 h post peak LH surge, respectively. For validation, qPCR and immunocytochemistry analyses were carried out for some of the differentially expressed genes. Expression analysis of many of these genes showed distinct expression patterns in GCs and the follicle wall. To study molecular functions and genetic networks, microarray data was analyzed using Ingenuity Pathway Analysis which revealed majority of the differentially expressed genes to cluster within processes like steroidogenesis, cell survival and cell differentiation. In the ovarian follicle, IGF-I is established to be an important regulator of the above mentioned molecular functions. Thus, further experiments were conducted to verify the effects of increased intrafollicular IGF-I levels on the expression of genes associated with the above mentioned processes. For this purpose, buffalo cows were administered with exogenous bGH to transiently increase circulating and intrafollicular concentrations of IGF-I. The results indicated that increased intrafollicular concentrations of IGF-I caused changes in expression of genes associated with steroidogenesis (StAR, SRF) and apoptosis (BCL-2, FKHR, PAWR). These results taken together suggest that onset of gonadotropin surge triggers activation of various biological pathways and that the effects of growth factors and peptides on gonadotropin actions could be examined during preovulatory follicle development.

Show MeSH