Group A Streptococcus (GAS) is among the top ten causes of infection-related mortality in humans. M protein is the most abundant GAS surface protein, and M1 serotype GAS strains are associated with invasive infections, including necrotizing fasciitis and toxic shock syndrome. Here, we report that released, soluble M1 protein triggers programmed cell death in macrophages (Mϕ). M1 served as a second signal for caspase-1-dependent NLRP3 inflammasome activation, inducing maturation and release of proinflammatory cytokine interleukin-1β (IL-1β) and macrophage pyroptosis. The structurally dynamic B-repeat domain of M1 was critical for inflammasome activation, which involved K efflux and M1 protein internalization by clathrin-mediated endocytosis. Mouse intraperitoneal challenge showed that soluble M1 was sufficient and specific for IL-1β activation, which may represent an early warning to activate host immunity against the pathogen. Conversely, in systemic infection, hyperinflammation associated with M1-mediated pyroptosis and IL-1β release could aggravate tissue injury.
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http://dx.doi.org/10.1038/s41564-017-0005-6 | DOI Listing |
Eur J Pharmacol
January 2025
Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Hubei Key Laboratory of Biological Targeted Therapy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Hubei Provincial Engineering Research Center of Immunological Diagnosis and Therapy for Cardiovascular Diseases, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China. Electronic address:
Background: Myocarditis tends to lead to a poor prognosis, but there are no satisfactory preventive or therapeutic strategies. Erianin, a natural benzene compound, has been found to have antioxidant and anti-inflammatory effects. However, the effects of erianin on myocarditis remain unclear.
View Article and Find Full Text PDFEcotoxicol Environ Saf
January 2025
Department of Forensic Medicine, School of Forensic Medicine, Kunming Medical University, Kunming, China. Electronic address:
Mushroom poisoning, predominantly caused by α-amanitin, is a critical food safety concern in worldwide, with severe cases leading to hepatotoxicity and fatalities. This study delves into the hepatotoxic effects of α-amanitin, focusing on the NLRP3 inflammasome and PPAR-γ's regulatory role in inflammation. In vitro studies with L-02 cells showed that α-amanitin reduces cell viability and triggers NLRP3 inflammasome activation, increasing NF-κB phosphorylation and pro-inflammatory cytokines IL-18 and IL-1β.
View Article and Find Full Text PDFInflamm Res
January 2025
Department of Ultrasound, The Second Xiangya Hospital of Central South University, Changsha, 410011, China.
Background: Hyperoxia-induced brain injury is a severe neurological complication that is often accompanied by adverse long-term prognosis. The pathogenesis of hyperoxia-induced brain injury is highly complex, with neuroinflammation playing a crucial role. The activation of the nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome, which plays a pivotal role in regulating and amplifying the inflammatory response, is the pathological core of hyperoxia-induced brain injury.
View Article and Find Full Text PDFPharmaceuticals (Basel)
January 2025
Department of Biochemistry and Pharmacology, School of Medicine, Universidade de Marília (UNIMAR), Marília 17525-902, São Paulo, Brazil.
Neuroinflammation is a key factor in the progression of neurodegenerative diseases, driven by the dysregulation of molecular pathways and activation of the brain's immune system, resulting in the release of pro-inflammatory and oxidative molecules. This chronic inflammation is exacerbated by peripheral leukocyte infiltration into the central nervous system. Medicinal plants, with their historical use in traditional medicine, have emerged as promising candidates to mitigate neuroinflammation and offer a sustainable alternative for addressing neurodegenerative conditions in a green healthcare framework.
View Article and Find Full Text PDFPharmaceuticals (Basel)
January 2025
Department of Molecular Bioscience, College of Biomedical Science, Kangwon National University, Chuncheon 24341, Republic of Korea.
: , a bacterium residing in hair follicles, triggers acne by inducing monocyte-mediated inflammatory cytokine production. Gedunin, a limonoid derived from (commonly known as neem), is renowned for its antifungal, antimalarial, anticancer, anti-inflammatory, and neuroprotective effects. However, its role in mitigating -induced skin inflammation remains unexplored.
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