Singh Sudha B, Braun Cody A, Carroll-Portillo Amanda, Coffman Cristina N, Lin Henry C
Biomedical Research Institute of New Mexico, New Mexico Veterans Affairs (VA) Health Care System, 1501 San Pedro Dr. SE, Albuquerque, NM 87108, USA.
Division of Gastroenterology and Hepatology, Department of Medicine, University of New Mexico, Albuquerque, NM 87131, USA.
Microorganisms. 2024 Sep 5;12(9):1833. doi: 10.3390/microorganisms12091833.
, resident gut sulfate-reducing bacteria (SRB), are found to overgrow in diseases such as inflammatory bowel disease and Parkinson's disease. They activate a pro-inflammatory response, suggesting that may play a causal role in inflammation. Class I phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway regulates key events in the inflammatory response to infection. Dysfunctional PI3K/Akt signaling is linked to numerous diseases. Bacterial-induced PI3K/Akt pathway may be activated downstream of toll-like receptor (TLR) signaling. Here, we tested the hypothesis that (DSV) may induce tumor necrosis factor alpha (TNF-α) and inducible nitric oxide synthase (iNOS) expression via PI3K/Akt in a TLR 2-dependent manner. RAW 264.7 macrophages were infected with DSV, and protein expression of p-Akt, p-p70S6K, p-NF-κB, p-IkB, TNF-α, and iNOS was measured. We found that DSV induced these proteins in a time-dependent manner. Heat-killed and live DSV, but not bacterial culture supernatant or a probiotic , significantly caused PI3K/AKT/TNF/iNOS activation. LY294002, a PI3K/Akt signaling inhibitor, and TL2-C29, a TLR 2 antagonist, inhibited DSV-induced PI3K/AKT pathway. Thus, DSV induces pro-inflammatory TNF-α and iNOS via PI3K/Akt pathway in a TLR 2-dependent manner. Taken together, our study identifies a novel mechanism by which SRB such as may trigger inflammation in diseases associated with SRB overgrowth.
肠道常驻硫酸盐还原菌(SRB)在炎症性肠病和帕金森病等疾病中过度生长。它们激活促炎反应,表明其可能在炎症中起因果作用。I类磷脂酰肌醇3激酶(PI3K)/蛋白激酶B(AKT)信号通路调节对感染的炎症反应中的关键事件。PI3K/Akt信号功能失调与多种疾病有关。细菌诱导的PI3K/Akt通路可能在Toll样受体(TLR)信号下游被激活。在此,我们测试了以下假设:解脲脲原体(DSV)可能通过PI3K/Akt以TLR 2依赖的方式诱导肿瘤坏死因子α(TNF-α)和诱导型一氧化氮合酶(iNOS)表达。用DSV感染RAW 264.7巨噬细胞,并检测p-Akt、p-p70S6K、p-NF-κB、p-IκB、TNF-α和iNOS的蛋白表达。我们发现DSV以时间依赖的方式诱导这些蛋白。热灭活的和活的DSV,但不是细菌培养上清液或益生菌,显著引起PI3K/AKT/TNF/iNOS激活。PI3K/Akt信号抑制剂LY294002和TLR 2拮抗剂TL2-C29抑制DSV诱导的PI3K/AKT通路。因此,DSV以TLR 2依赖的方式通过PI3K/Akt通路诱导促炎TNF-α和iNOS。综上所述,我们的研究确定了一种新机制,即解脲脲原体等SRB可能在与SRB过度生长相关的疾病中引发炎症。
Front Cell Infect Microbiol. 2021
Microorganisms. 2023-7-7
Int Immunopharmacol. 2011-12-20
Front Pharmacol. 2025-5-27
Front Microbiol. 2025-4-30
Int J Mol Sci. 2025-4-3
Medicine (Baltimore). 2023-9-15
Microorganisms. 2023-7-7
Semin Immunol. 2023-9
Cell Host Microbe. 2023-6-14
Inflamm Res. 2023-5