Toll-like receptors (TLR) 2 and 4 on human sperm recognize bacterial endotoxins and mediate apoptosis.

Hum Reprod

Laboratory of Reproductive Endocrinology, Department of Applied Animal Science, Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8528, Japan.

Published: October 2011

Background: Bacterial infections of the genital tract are one of the most serious causes of infertility in males. In some human patients with poor semen quality, leukocytospermia has been observed. Because leukocytes express the bacterial-lipopolysaccharide (LPS) responsive Toll-like receptor (TLR) signaling cascade and secrete tumor necrosis factor-α, secreted cytokines comprise one, but probably not the only, class of factors that can impact sperm motility.

Methods And Results: In this study, we documented that bacterial endotoxins, LPS and peptidoglycan, can be detected in human semen. Furthermore, the addition of endotoxins in the absence of leukocytes directly and significantly reduced the motility and increased the apoptotic rate of both human and mouse sperm and suppressed fertilization by mouse sperm both in vivo and in vitro. The well-known LPS receptor, TLR4, and peptidoglycan receptor, TLR2, were expressed in human and mouse sperm. In Tlr2/4(-/-) double-mutant mice, the negative effects of endotoxins on sperm functions were blocked, suggesting that the bacterial endotoxins mediated activation of TLR-dependent pathways in sperm leading to apoptosis.

Conclusions: Sperm can recognize bacterial endotoxins by TLRs present in their membranes. The activated TLRs reduce sperm motility, induce sperm apoptosis and significantly impair the potential for fertilization.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3174031PMC
http://dx.doi.org/10.1093/humrep/der234DOI Listing

Publication Analysis

Top Keywords

bacterial endotoxins
16
mouse sperm
12
sperm
10
sperm recognize
8
recognize bacterial
8
human mouse
8
endotoxins
6
human
5
bacterial
5
toll-like receptors
4

Similar Publications

Enteropathogenic Escherichia coli (EPEC) is a significant bacterial pathogen that causes infantile diarrhea, particularly in low- and middle-income countries. The lack of a reliable diagnostic method greatly contributes to the increased occurrence and severity of the disease. This study aimed at developing of a cost-effective, rapid, and efficient immunodiagnostic assay for detecting EPEC infection.

View Article and Find Full Text PDF

Shiga toxin-producing Escherichia coli (STEC) is one of the major pathogens responsible for severe foodborne infections, and the common serotypes include E. coli O157, O26, O45, O103, O111, O121, and O145. Vaccination has the potential to prevent STEC infections, but no licensed vaccines are available to provide protection against multiple STEC infections.

View Article and Find Full Text PDF

IRF1 cooperates with ISGF3 or GAF to form innate immune de novo enhancers in macrophages.

Sci Signal

January 2025

Department of Microbiology, Immunology and Molecular Genetics, UCLA, Los Angeles, CA, USA.

Macrophages exposed to immune stimuli reprogram their epigenomes to alter their subsequent functions. Exposure to bacterial lipopolysaccharide (LPS) causes widespread nucleosome remodeling and the formation of thousands of de novo enhancers. We dissected the regulatory logic by which the network of interferon regulatory factors (IRFs) induces the opening of chromatin and the formation of de novo enhancers.

View Article and Find Full Text PDF

Inactivation of Lipopolysaccharide-Biosynthesizing Genes Altered Lipids Composition and Intensity in .

Pathogens

November 2024

Guangzhou CnFerment Biotechnology Co., Ltd., Guangzhou 510440, China.

Gram-negative bacteria possess an asymmetric outer membrane, where the outer leaflet consists of LPSs and the inner leaflet comprises phospholipids. , an opportunistic milk-borne pathogen that causes severe neonatal meningitis and bacteremia, displays diverse lipopolysaccharide (LPS) structures. As a barrier of the bacterial cell, LPSs likely influenced resistance to environment stresses; however, there are no research reports on this aspect, hindering the development of novel bactericidal strategies overcoming the pathogen's resilience.

View Article and Find Full Text PDF

Developing simple and efficient multi-gene expression systems is crucial for multi-trait improvement or bioproduction in transgenic plants. In previous research, an -based bicistronic system from the nonpathogenic fungus efficiently expressed multiple enzyme proteins in yeast and maize, and the heterologous enzymes successfully performed their catalytic activity to reconstruct the biosynthetic pathway in the host organism. Unlike enzyme proteins, some heterologous functional proteins (such as insecticidal proteins) are dose-dependent and they need to express sufficient levels to perform their biological functions.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!