Profiling and integrated analysis of whole-transcriptome changes in uterine caruncles of pregnant and non-pregnant buffaloes.

Improved reproductive performance in buffaloes can be achieved by understanding the basic mechanism governing the embryonic attachment and feto-maternal communication. Considering this, trascriptomic profiling and integrative analysis of long intergenic non-coding RNAs were carried out in the uterine caruncles of pregnant and non-pregnant buffaloes. Transcriptome data of pregnant and non-pregnant uterine caruncles after quality control was used to perform the analysis. Total of 86 novel lincRNAs expressed in uterine caruncular tissues were identified and characterized. Differential expression analysis revealed that 447 mRNAs and 185 mRNAs were up- and down- regulated, respectively. The number of up- and down- regulated lincRNAs were 114 and 13, respectively. Of the identified 86 novel lincRNAs, six novel lincRNAs were up-regulated in the pregnant uterine caruncles. GO terms (biological process) and PANTHER pathways associated with reproduction and embryogenesis were over-represented in differentially expressed genes. Through miRNA interaction analysis, interactions of 16 differentially expressed lincRNAs with mi-RNAs involved in reproduction were identified. This study has provided a catalogue of differentially expressed genes and novel regions previously unknown to play a significant role in buffalo reproduction. The results from the current study extends the buffalo uterine lncRNAs database and provides candidate regulators for future molecular genetic studies on buffalo uterine physiology to improve the embryo implantation and successful completion of pregnancy.

Impact of uterine macrophage phenotype on placental retention in dairy cows.

Reproductive diseases affect 25% of dairy cows in the US and often develop from retention of the placenta. It is well established that expulsion of the placenta is a highly regulated inflammatory process, but the mechanisms by which dysregulation of uterine immune responses impair this process are poorly understood. In healthy non-ruminants, pro-inflammatory M1 macrophages are predominant in uterine tissue after parturition. However, macrophage phenotype in the postpartum bovine uterus is unknown. Our study compared macrophage phenotypes in the uterine caruncles of multiparous dairy cows that during the first day postpartum either retained (RET, n = 5) or had normal expulsion (NOR, n = 5) of placenta. Immune cells were sorted magnetically from the caruncular endometrial cell fraction using the CD172a marker and monocyte/macrophage population was characterized using flow cytometry. Transcriptional and protein expression studies were performed on uterine caruncles. Compared to NOR, RET samples showed a lower CD14+/CD16+ expression (P < 0.05) in caruncle monocyte/macrophage population. As opposed to NOR, RET further demonstrated greater expression of anti-inflammatory M2 macrophage associated genes CD206, C-type lectin domain family 7 member A (CLEC7A), and RNASE6. In addition, caruncles from RET showed decreased signal transducer and activator of transcription 3 (STAT3) activation, an important promoter of proteolytic activity, compared to NOR. Our studies demonstrate that there is an overall lower number of macrophage populations in the caruncle of cows with RET placenta and these are polarized towards M2 phenotype. Excessive accumulation of M2 macrophages may lead to reduced trafficking of immune cells into the caruncle thus impairing the inflammatory, phagocytic and proteolytic processes that lead to placental expulsion.