Comprehensive RNA-seq profiling to evaluate the rabbit mammary gland transcriptome after mastitis.

Mastitis is a relatively common disease in rabbit does. The aim of this study was to investigate a relationship between the severity of clinical signs and pathological observations and to analyze differentially expressed genes (DEGs) in the mammary gland with mastitis versus healthy mammary gland. The result showed that rectal temperatures of the rabbits with both mild mastitis and severe mastitis were higher than that of control. Cell counting results showed that the somatic cell count (SCC) only in milk of the rabbit with severe mastitis was significantly higher than that in the control group. However, the number of heterophils in the histological sections of mammary glands with mild mastitis was significantly higher than that of control. A total of 1,096 DEGs between the control and mastitis mammary glands was identified by RNA-sequencing (RNA-seq). Gene ontology (GO) showed that most of up-regulated genes were enriched in terms such as response to stimulus, signal transduction, and cell communication. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that these genes were mostly enriched in the pathways such as Rap1 signaling pathway, proteoglycans in cancer, and PI3K-Akt signaling pathway. However, the downregulated genes were mainly enriched in metabolic processes and significantly involved in metabolic pathways. The data provides useful information to further dissect the molecular genetic mechanisms underlying rabbit mastitis, which is a prerequisite for designing effective intervention strategies.

S100A4 promotes the progression of lipopolysaccharide-induced acute epididymitis in mice†.

S100A4 has been suggested to be a critical regulator of tumor metastasis and is implicated in the progression of inflammation. The aim of this study is to investigate the expression and possible role of S100A4 in epididymitis. Using a mouse model of epididymitis induced by the injection of lipopolysaccharide (LPS) in the deferent duct, we found that LPS administration induced an upregulation of S100a4 transcription (P < 0.05) and a recruitment of S100A4 positive cells in the epididymal interstitium of wild type (WT) mice. Co-immunofluorescence showed that S100A4 was mainly expressed by granulocytes, CD4 lymphocytes, and macrophages. Deficiency of S100A4 reduced epididymal pathological reaction and the mRNA levels of the pro-inflammatory cytokines IL-1ß and TNF-α (P < 0.01), suggesting that S100A4 promotes the progression of epididymitis. Furthermore, S100A4 deficiency alleviated the decline of sperm motility and rectified the abnormal expression of sperm membrane protein AMAD3, which suggested that in the progression of epididymitis, S100A4 aggravates the damage to sperm vitality. In addition, both Ki-67 marked cell proliferation and transferase-mediated dUTP-biotin nick end labeling detected cell apoptosis were reduced in S100a4-/- mice compared with WT mice after LPS treatment, indicating that S100A4 promotes both cell proliferation and cell apoptosis in epididymitis. Overall, these results demonstrate that S100A4 promotes the progression of LPS-induced epididymitis and facilitates a decline in sperm vitality, and its function may be related to the process of cell proliferation and apoptosis during inflammation.

S100A4 promotes the development of lipopolysaccharide-induced mouse endometritis.

S100A4 is suggested to be a critical regulator of tumor metastasis, and implicated in progression of inflammation. The aim of this study is to investigate the expression and possible role of S100A4 in endometritis. Using a mouse model of endometritis induced by local injection of lipopolysaccharide (LPS), we found that infection induced recruitment of S100A4-positive cells in the endometrium of wild-type mice. Deficiency of S100A4 reduced uterine pathological reaction and mRNA expression of proinflammatory cytokine IL-1ß and TNF-α (P < 0.01), suggesting S100A4 promoted the progression of endometritis. To further explore the potential mechanism, we examined the cellular proliferation and apoptosis in the endometrium. Western blot and immunohistochemical results showed that cell apoptosis in uterus during endometritis, marked by cleaved-Caspase 3 protein, was significantly cut down in S100a4-/- mice; cell proliferation, which was indicated by Ki-67, was also significantly decreased in the inflamed endometrial stroma of S100a4-/- mice. Overall, these results demonstrate that S100A4 promotes the development of LPS-induced endometritis, and it may be related to the process of cell proliferation and apoptosis during the inflammation.

miR-148a-3p promotes rabbit preadipocyte differentiation by targeting PTEN.

Although emerging data support crucial roles for microRNAs (miRNAs) during adipogenesis, the detailed mechanisms remain largely unknown. In this study, it was shown that in rabbits, levels of miR-148a-3p not only increased in white adipose tissue during early stages of growth but also during in vitro cultured preadipocyte differentiation. Furthermore, overexpression of miR-148a-3p significantly upregulated the mRNA levels of PPARγ, C/EBPα, and FABP4, as well as the protein levels of PPARγ, as indicated by qPCR and western blotting analyses. Overexpression of miR-148a-3p also promoted intracellular triglyceride accumulation. In contrast, downregulation of miR-148a-3p inhibited the differentiation of rabbit preadipocytes. Next, based on target gene prediction and a luciferase reporter assay, we further demonstrated that miR-148a-3p directly targeted one of the 3' untranslated regions of PTEN. Finally, it was observed inhibition of PTEN by siRNA promoted rabbit preadipocyte differentiation. Taken together, our results suggested that miR-148a-3p could be involved in regulating rabbit preadipocyte differentiation through inhibiting expression of PTEN, which further highlighted the importance of miRNAs during adipogenesis.