RNAi-mediated knockdown of without disrupting the effects of melatonin on apoptosis and cell cycle in bovine granulose cells.

Melatonin is well known as a powerful free radical scavenger and exhibits the ability to prevent cell apoptosis. In the present study, we investigated the role of melatonin and its receptor in regulating the function of bovine granulosa cells (GCs) and hypothesized the involvement of in mediating the effect of melatonin on GCs. Our results showed that knockdown significantly promoted GCs apoptosis but did not affect the cell cycle. These results were further verified by increasing the expression of pro-apoptosis genes ( and ), decreasing expression of the anti-apoptosis genes ( and ) and anti-oxidant genes ( and ) without affecting cell cycle factors (, and ) and . In addition, knockdown did not disrupt the effects of melatonin in suppressing the GCs apoptosis or blocking the cell cycle. Moreover, knockdown did not affect the role of melatonin in increasing , , and expression, or decreasing , , , and expression. The expression of was upregulated after knockdown, and melatonin promoted expression with or without knockdown. However, despite melatonin supplementation, the expression of and was still suppressed after knockdown. In conclusion, these findings indicate that melatonin and are involved in family and -dependent apoptotic pathways in bovine GCs. MTNR1A and MTNR1B may coordinate the work of medicating the appropriate melatonin responses to GCs.