The aryl hydrocarbon receptor (AhR) has been implicated in regulating skeletal progenitor cells and the activity of bone-forming osteoblasts and bone-resorbing osteoclasts, thereby impacting bone mass and the risk of skeletal fractures. The AhR also plays an important role in the immune system within the skeletal niche and in the differentiation of mesenchymal stem cells into other cell lineages including chondrocytes and adipocytes. This transcription factor responds to environmental pollutants which can act as AhR ligands, initiating or interfering with various signaling cascades to mediate downstream effects, and also responds to endogenous ligands including tryptophan metabolites. This review comprehensively describes the reported roles of the AhR in skeletal cell biology, focusing on mesenchymal stem cells, osteoblasts, and osteoclasts, and discusses how AhR exhibits sexually dimorphic effects in bone. The molecular mechanisms mediating AhR's downstream effects are highlighted to emphasize the potential importance of targeting this signaling cascade in skeletal disorders.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9448512 | PMC |
http://dx.doi.org/10.1530/JME-22-0076 | DOI Listing |
Exp Neurol
January 2025
Laboratory of Neurodegenerative Diseases and Neuroinjury Diseases, Wuxi, School of Medicine, Jiangnan University, Wuxi, Jiangsu 214122, China; MOE Medical Basic Research Innovation Center for Gut Microbiota and Chronic Diseases, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu 214122, China. Electronic address:
Abnormal tryptophan metabolism is closely linked with neurological disorders. Research has shown that indoleamine 2,3-dioxygenase 1 (IDO-1), the first rate-limiting enzyme in tryptophan degradation, is upregulated in Parkinson's disease (PD). However, the precise role of IDO-1 in PD pathogenesis remains elusive.
View Article and Find Full Text PDFCells
January 2025
Research Institute of Medical and Health Sciences, University of Sharjah, Sharjah P.O. Box 27272, United Arab Emirates.
The Kynurenine pathway is crucial in metabolizing dietary tryptophan into bioactive compounds known as kynurenines, which have been linked to glucose homeostasis. The aryl hydrocarbon receptor (AhR) has recently emerged as the endogenous receptor for the kynurenine metabolite, kynurenic acid (KYNA). However, the specific role of AhR in pancreatic β-cells remains largely unexplored.
View Article and Find Full Text PDFCell Host Microbe
January 2025
State Key Laboratory of Female Fertility Promotion, Center for Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing, China; Institute of Advanced Clinical Medicine, Peking University, National Clinical Research Center for Obstetrics and Gynecology (Peking University Third Hospital), Beijing, China; Beijing Key Laboratory of Reproductive Endocrinology and Assisted Reproductive Technology, Beijing, China. Electronic address:
Polycystic ovary syndrome (PCOS) affects 6%-10% of women of reproductive age and is known to be associated with disruptions in the gut bacteria. However, the role of the gut mycobiota in PCOS pathology remains unclear. Using culture-dependent and internal transcribed spacer 2 (ITS2)-sequencing methods, we discovered an enrichment of the gut-colonizable fungus Aspergillus tubingensis in 226 individuals, with or without PCOS, from 3 different geographical areas within China.
View Article and Find Full Text PDFNat Microbiol
January 2025
Section of General Surgery, Department of Surgery, University of Chicago, Chicago, IL, USA.
Sepsis is a major cause of morbidity and mortality, but our understanding of the mechanisms underlying survival or susceptibility is limited. Here, as pathogens often subvert host defence mechanisms, we hypothesized that this might influence the outcome of sepsis. We used microbiota analysis, faecal microbiota transplantation, antibiotic treatment and caecal metabolite analysis to show that gut-microbiota-derived tryptophan metabolites including indoles increased host survival in a mouse model of Serratia marcescens sepsis.
View Article and Find Full Text PDFFunction (Oxf)
January 2025
Cardio-Renal Physiology and Medicine Section, Division of Nephrology.
Excess dietary salt and salt-sensitivity contribute to cardiovascular disease. Distinct T cell phenotypic responses to high salt and hypertension as well as influences from environmental cues are not well understood. The aryl hydrocarbon receptor (AhR) is activated by dietary ligands, promoting T cell and systemic homeostasis.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!