Immunomodulatory dynamics in the porcine myometrium: global transcriptome analysis, including the effects of PPARγ...

The myometrium is involved in many processes during pregnancy and the estrous/menstrual cycle. Peroxisome proliferator-activated receptors (PPARs) can be regulators of the processes occurring in the myometrium. In the present study, we determined the global transcriptome profile of the porcine myometrium during the peri-implantation period and the late luteal phase of the estrous cycle. In addition, we investigated for the first time the influence of PPARγ ligands on the transcriptome profile.

The myometrium of gilts (n = 3) was collected on days 10-11 and 14-15 of pregnancy and on the corresponding days of the estrous cycle. The expression of PPARγ was confirmed in the tissue. Based on the mRNA level, further studies were conducted on myometrial explants obtained from pigs at days 14-15 of pregnancy and the corresponding days of the estrous cycle. The tissue sections were incubated in vitro for 6 h in the presence of a PPARγ agonist, pioglitazone (P; 10 µM), or antagonist, T0070907 (T; 1 µM). To identify the transcription profile of the myometrium, RNA-Seq was performed on the NovaSeq 6000 Illumina platform. This study identified 1082 differentially expressed genes (DEGs; 609 upregulated and 473 downregulated) in the porcine myometrium on days 14-15 of pregnancy compared with the corresponding days of the estrous cycle. During pregnancy, we detected 6 and 80 DEGs related to PPARγ agonist and antagonist, respectively. During the estrous cycle, we identified 4 and 17 DEGs for P and T vs. the control, respectively.

The results indicate that the DEGs are involved in a number of processes, including the immune response, prostaglandin synthesis, cell differentiation and communication. In addition, the role of PPARγ activity in regulating the expression of genes related to the immune response and hormone synthesis in the porcine myometrium has been demonstrated.