Testicular exosomes disturb the immunosuppressive phenotype of testicular macrophages mediated by miR-155-5p in uropathogenic Escherichia coli-induced orchitis

Exosomes derived from bladder epithelial cells infected with uropathogenic Escherichia coli increase the severity of urinary tract infections (UTIs) by impairing macrophage function

Uropathogenic Escherichia coli (UPEC) is the primary causative agent of urinary tract infections (UTIs) in humans. Moreover, as one of the most common bacterial pathogens, UPEC imposes a substantial burden on healthcare systems worldwide. Epithelial cells and macrophages are two major components of the innate immune system, which play critical roles in defending the bladder against UPEC invasion. Yet, the routes of communication between these cells during UTI pathogenesis are still not fully understood. In the present study, we investigated the role of membrane-bound nanovesicles (exosomes) in the communication between bladder epithelial cells and macrophages during UPEC infection, using an array of techniques such as flow cytometry, miRNA profiling, RNA sequencing, and western blotting. Moreover, our in vitro findings were validated in a mouse model of UPEC-induced cystitis. We found that UPEC infection induced the bladder epithelial MB49 cell line to secrete large numbers of exosomes (MB49-U-Exo), which were efficiently absorbed by macrophages both in vivo and in vitro. Assimilation of MB49-U-Exo induced macrophages to produce proinflammatory cytokines, including tumor necrosis factor (TNF)α. Exposure of macrophages to MB49-U-Exo reduced their phagocytic activity (by downregulating the expression of phagocytosis-related genes) and increased their rate of apoptosis. Mechanistically, we showed that MB49-U-Exo were enriched in miR-18a-5p, which induced TNFα expression in macrophages by targeting PTEN and activating the MAPK/JNK signaling pathway. Moreover, administration of the exosome secretion inhibitor GW4869 or a TNFα-neutralizing antibody alleviated UPEC-mediated tissue damage in mice with UPEC-induced cystitis by reducing the bacterial burden of the bladder and dampening the associated inflammatory response. Collectively, these findings suggest that MB49-U-Exo regulate macrophage function in a way that exacerbates UPEC-mediated tissue impairment. Thus, targeting exosomal -release or TNFα signaling during UPEC infection may represent promising non-antibiotic strategies for treating UTIs.

Identification of key genes affecting sperm motility in chicken based on whole-transcriptome sequencing

Sperm motility is an important index for the evaluation of semen quality. Improving sperm motility is important to improve reproductive performance, promote breeding process, and reduce production cost. However, the molecular mechanisms regulating sperm motility in chickens remain unclear. In this study, histological observation and whole-transcriptome analysis were performed on testicular tissue of chickens with high and low sperm motility. Histological observations showed that roosters with high sperm motility exhibited better semen quality than those with low sperm motility. In addition, the germinal epithelial cells of roosters with low sperm motility were loosely arranged and contained many vacuoles. RNA-seq results revealed the expression of 23,033 mRNAs, 2,893 lncRNAs, and 515 miRNAs in chicken testes. Among them, there were 417 differentially expressed mRNAs (DEmRNAs), 106 differentially expressed lncRNAs (DElncRNAs), and 15 differentially expressed miRNAs (DEmiRNAs) between high and low sperm motility testes. These differentially expressed genes were involved in the G protein-coupled receptor signaling pathway, cilia structure, Wnt signaling, MAPK signaling, GnRH signaling, and mTOR signaling. By integrating the competitive relationships between DEmRNAs, DElncRNAs, and DEmiRNAs, we identified the regulatory pathway of MSTRG.3077.3/MSTRG.9085.1-gga-miR-138-5p-CADM1 and MSTRG.2290.1-gga-miR-142-3p-GNAQ/PPP3CA as crucial in the modulation of chicken sperm motility. This study provides new insights into the function and mechanism of ceRNAs in regulating sperm motility in chicken testes.

Microbiology and immune mechanisms associated with male infertility

Up to 50% of infertility is caused by the male side. Varicocele, orchitis, prostatitis, oligospermia, asthenospermia, and azoospermia are common causes of impaired male reproductive function and male infertility. In recent years, more and more studies have shown that microorganisms play an increasingly important role in the occurrence of these diseases. This review will discuss the microbiological changes associated with male infertility from the perspective of etiology, and how microorganisms affect the normal function of the male reproductive system through immune mechanisms. Linking male infertility with microbiome and immunomics can help us recognize the immune response under different disease states, providing more targeted immune target therapy for these diseases, and even the possibility of combined immunotherapy and microbial therapy for male infertility.