Mst1/2-ALK promotes NLRP3 inflammasome activation and cell apoptosis during Listeria monocytogenes infection

Author(s):  
Aijiao Gao ◽  
Huixin Tang ◽  
Qian Zhang ◽  
Ruiqing Liu ◽  
Lin Wang ◽  
...  
2017 ◽  
Vol 42 (4) ◽  
pp. 1635-1644 ◽  
Author(s):  
Zhu-lin Luo ◽  
Jian-dong Ren ◽  
Zhu Huang ◽  
Tao Wang ◽  
Ke Xiang ◽  
...  

Background: This study aimed to investigate whether exogenous hydrogen sulfide (H2S) can protect the RAW264.7 macrophages against the inflammation induced by free fatty acids (FFA) by blunting NLRP3 inflammasome activation via a specific TLR4/NF-κB pathway. Methods: RAW264.7 macrophages were exposed to increasing concentrations of FFA for up to 3 days to induce FFA-induced inflammation. The cells were pretreated with NaHS (a donor of H2S) before exposure to FFA. Cell viability, cell apoptosis, TLR4, NF-κB, NLRP3 inflammasome, IL-1β, IL-18 and cleaved caspase-3 expression were measured by a combination of MTT assay, ELISA, and immunoblotting. Results: H2S attenuated FFA-induced cell apoptosis, and reduced the expression of NLRP3, ASC, pro-caspase-1, caspase-1, IL- 1β, IL-18 and caspase-3. In addition, H2S inhibited the FFA-induced activation of TLR4 and NF-κB. Furthermore, NLRP3 inflammasome activation was regulated by the TLR4 and NF-κB pathway. Conclusion: The present study demonstrated for the first time that H2S appears to suppress FFA-induced macrophage inflammation and apoptosis by inhibiting the TLR4/ NF-κB pathway and its downstream NLRP3 inflammasome activation. Thus H2S might possess potential in the treatment of diseases resulting from FFA overload like insulin resistance and type diabetes.


Bone Research ◽  
2022 ◽  
Vol 10 (1) ◽  
Author(s):  
Sheng Chen ◽  
Xiaohao Wu ◽  
Yumei Lai ◽  
Di Chen ◽  
Xiaochun Bai ◽  
...  

AbstractIntervertebral disc (IVD) degeneration (IVDD) is the main cause of low back pain with major social and economic burdens; however, its underlying molecular mechanisms remain poorly defined. Here we show that the focal adhesion protein Kindlin-2 is highly expressed in the nucleus pulposus (NP), but not in the anulus fibrosus and the cartilaginous endplates, in the IVD tissues. Expression of Kindlin-2 is drastically decreased in NP cells in aged mice and severe IVDD patients. Inducible deletion of Kindlin-2 in NP cells in adult mice causes spontaneous and striking IVDD-like phenotypes in lumbar IVDs and largely accelerates progression of coccygeal IVDD in the presence of abnormal mechanical stress. Kindlin-2 loss activates Nlrp3 inflammasome and stimulates expression of IL-1β in NP cells, which in turn downregulates Kindlin-2. This vicious cycle promotes extracellular matrix (ECM) catabolism and NP cell apoptosis. Furthermore, abnormal mechanical stress reduces expression of Kindlin-2, which exacerbates Nlrp3 inflammasome activation, cell apoptosis, and ECM catabolism in NP cells caused by Kindlin-2 deficiency. In vivo blocking Nlrp3 inflammasome activation prevents IVDD progression induced by Kindlin-2 loss and abnormal mechanical stress. Of translational significance, adeno-associated virus-mediated overexpression of Kindlin-2 inhibits ECM catabolism and cell apoptosis in primary human NP cells in vitro and alleviates coccygeal IVDD progression caused by mechanical stress in rat. Collectively, we establish critical roles of Kindlin-2 in inhibiting Nlrp3 inflammasome activation and maintaining integrity of the IVD homeostasis and define a novel target for the prevention and treatment of IVDD.


2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Qiang Zheng ◽  
Hang Zhao ◽  
Dong Jia ◽  
Xu Han ◽  
Zhenning Liu ◽  
...  

Paraquat (PQ) can cause multiorgan failure including acute kidney injury (AKI). Our prior study showed that Toll-interacting protein (TOLLIP) protected against PQ-induced acute lung injury. However, the role of TOLLIP in PQ-induced AKI remains undefined. This study was aimed at understanding the role and mechanism of TOLLIP in AKI. Six-eight-week-old male Wistar rats were intraperitoneally injected with 25 mg/kg PQ to induce AKI for 24 h in vivo. HK-2 cells were treated with 300 μM PQ for 24 h to induce cellular injury in vitro or 300 μM PQ and 5 μM nuclear factor-κB (NF-κB) inhibitor BAY11-7082 for 24 h. Rats were infected with adenovirus carrying TOLLIP shRNA via tail vein injection and HK-2 cells with adenovirus carrying TOLLIP shRNA or TOLLIP 48 h before PQ exposure. Results showed that TOLLIP and Toll-like receptor 2/4 (TLR2/4) expressions were boosted in the kidney after PQ intoxication. The toxic effect of PQ on the kidney and HK-2 cells was exacerbated by TOLLIP knockdown, as evidenced by aggravated glomerulus and tubule injury, inflammatory infiltration, and cell apoptosis in the kidney and increased loss of cell viability and apoptotic cells in HK-2 cells. TOLLIP knockdown also enhanced PQ-induced NLR family pyrin domain-containing 3 (NLRP3) inflammasome activation in vivo and in vitro and TLR2/4-NF-κB signaling in vitro, reflected by increased contents of proinflammatory cytokines and expressions of NLRP3 inflammasome-related proteins in the kidney and HK-2 cells and expressions of TLR2, TLR4, and nuclear NF-κB p65 in HK-2 cells. However, TOLLIP overexpression inhibited PQ-induced loss of cell viability, cell apoptosis, NLRP3 inflammasome activation, and TLR2/4-NF-κB signaling in vitro. Additionally, BAY11-7082 abolished TOLLIP knockdown-induced NLRP3 inflammasome activation in vitro, indicating that TOLLIP protected against NLRP3 inflammasome activation in PQ-induced AKI through inhibiting TLR2/4-NF-κB signaling. This study highlights the importance of TOLLIP in AKI after PQ intoxication.


2016 ◽  
Vol 40 (6) ◽  
pp. 1578-1590 ◽  
Author(s):  
Zena Huang ◽  
Xiaodong Zhuang ◽  
Chuli Xie ◽  
Xun Hu ◽  
Xiaobian Dong ◽  
...  

Background/Aims: This study aimed to investigate whether exogenous hydrogen sulfide (H2S) confered cardiac protection against high glucose (HG)-induced injury by inhibiting NLRP3 inflammasome activation via a specific TLR4/NF-κB pathway. Methods: H9c2 cardiac cells were exposed to 33 mM glucose for 24 h to induce HG-induced cytotoxicity. The cells were pretreated with NaHS (a donor of H2S) before exposure to HG. Cell viability, cell apoptosis, intracellular reactive oxygen species (ROS), mitochondrial membrane potential (MMP), and TLR4, NF-κB, NLRP3 inflammasome, IL-1β, IL-18 and caspase-3 expression were measured by standard methods. Results: H2S attenuated HG-induced cell apoptosis, ROS expression and loss of MMP and reduced the expression of NLRP3, ASC, pro-caspase-1, caspase-1, IL-1β, IL-18 and caspase-3. In addition, H2S inhibited the HG-induced activation of TLR4 and NF-κB. Furthermore, NLRP3 inflammasome activation was regulated by the TLR4 and NF-κB pathway. Conclusion: The present study demonstrated for the first time that H2S appears to suppress HG-induced cardiomyocyte inflammation and apoptosis by inhibiting the TLR4/NF-κB pathway and its downstream NLRP3 inflammasome activation. Thus H2S might possess potential in the treatment of diabetic cardiomyopathy.


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