Inflammasome Activation Induced by a Snake Venom Lys49-Phospholipase A2 Homologue

Background: Snake venom phospholipases A2 (PLA2s) have hemolytic, anticoagulant, myotoxic, oedematogenic, bactericidal, and inflammatory actions. BthTX-I, a Lys49-PLA2 isolated from Bothrops jararacussu venom, is an example of Lys49-PLA2 that presents such actions. NLRP3 is a cytosolic receptor from the NLR family responsible for inflammasome activation via caspase-1 activation and IL-1β liberation. The study of NLRs that recognize tissue damage and activate the inflammasome is relevant in envenomation. Methods: Male mice (18–20 g) received an intramuscular injection of BthTX-I or sterile saline. The serum was collected for creatine-kinase (CK), lactate dehydrogenase (LDH), and interleukin-1β (IL-1β) assays, and muscle was removed for inflammasome activation immunoblotting and qRT-PCR expression for nucleotide and oligomerization domain, leucine-rich repeat-containing protein family, pyrin-containing domain 3 receptor (NLRP3) inflammasome components. Results: BthTX-I-induced inflammation and myonecrosis, shown by intravital microscope, and LDH and CK release, respectively. Mouse treatment with A438079, a P2X7 receptor antagonist, did not modify these effects. BthTX-I induced inflammasome activation in muscle, but P2X7R participation in this effect was not observed. Conclusion: Together, the results showed for the first time that BthTX-I in gastrocnemius muscle induces inflammation and consequently, inflammasome activation via NLRP3 with caspase-1 activation and IL-1β liberation.

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Yao syndrome: A potential role and association of vasoactive intestinal peptide with NOD2

Rheumatology and Immunology Research ◽

10.2478/rir-2021-0005 ◽

2021 ◽

Vol 2 (1) ◽

pp. 57-59

Author(s):

Brianne Navetta-Modrov ◽

Berhane Ghebrehiwet ◽

Qingping Yao

Keyword(s):

Mast Cell ◽

Vasoactive Intestinal Peptide ◽

Autoinflammatory Disease ◽

Potential Role ◽

Mechanistic Study ◽

First Time ◽

Cytosolic Receptor ◽

Cell Disorder ◽

Oligomerization Domain

Abstract Nucleotide-binding oligomerization domain containing protein 2 (NOD2) is a cytosolic receptor. Both NOD2 and vasoactive intestinal peptide (VIP) are critical in regulation of immune and inflammatory response. Yao syndrome (YAOS, OMIM 617321) is an autoinflammatory disease associated with specified NOD2 mutations. Herein, we report a well-studied case of YAOS masquerading as mast cell disorder and neuroendocrine tumors to support the involvement of VIP in YAOS. For the first time, this case study suggests a potential relationship between NOD2 and VIP. This could provide a novel avenue for mechanistic study of NOD2-associated disease.

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Rac1 GTPase Inhibition Blocked Podocyte Injury and Glomerular Sclerosis during Hyperhomocysteinemia via Suppression of Nucleotide-Binding Oligomerization Domain-Like Receptor Containing Pyrin Domain 3 Inflammasome Activation

Kidney & Blood Pressure Research ◽

10.1159/000500457 ◽

2019 ◽

Vol 44 (4) ◽

pp. 513-532 ◽

Cited By ~ 2

Author(s):

Qinghua Zhang ◽

Sabena M. Conley ◽

Guangbi Li ◽

Xinxu Yuan ◽

Pin-Lan Li

Keyword(s):

Nlrp3 Inflammasome ◽

Glomerular Sclerosis ◽

Inflammasome Activation ◽

Glomerular Injury ◽

Podocyte Injury ◽

Pyrin Domain ◽

Nlrp3 Inflammasome Activation ◽

Rac1 Gtpase ◽

Domain 3 ◽

Oligomerization Domain

Elevated homocysteine (Hcy) levels have been shown to activate nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3) inflammasome leading to podocyte dysfunction and glomerular injury. However, it remains unclear how this inflammasome activation in podocytes is a therapeutic target for reversal of glomerular injury and ultimate sclerosis. The present study tested whether inhibition of Rac1 GTPase activity suppresses NLRP3 inflammation activation and thereby blocks podocyte injury induced by elevated Hcy. In cultured podocytes, we found that L-Hcy (the active Hcy form) stimulated the NLRP3 inflammasome formation, as shown by increased colocalization of NLRP3 with apoptosis-associated speck-like protein (ASC) or caspase-1, which was accompanied by increased interleukin-1β production and caspase-1 activity, indicating NLRP3 inflammasome activation. Rac1 activator, uridine triphosphate (UTP), mimicked L-Hcy-induced NLRP3 inflammasome activation, while Rac1 inhibitor NSC23766 blocked it. This Rac1 inhibition also prevented L-Hcy-induced podocyte dysfunction. All these effects were shown to be mediated via lipid raft redox signaling platforms with nicotinamide adenine dinucleotide phosphate oxidase subunits and consequent O2– production. In animal studies, hyperhomocysteinemia (hHcy) induced by folate-free diet was shown to induce NLRP3 inflammasome formation and activation in glomeruli, which was also mimicked by UTP and inhibited by NSC23766 to a comparable level seen in Nlrp3 gene knockout mice. These results together suggest that Rac1 inhibition protects the kidney from hHcy-induced podocyte injury and glomerular sclerosis due to its action to suppress NLRP3 inflammasome activation in podocytes.

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Heme oxygenase-1 dampens the macrophage sterile inflammasome response and regulates its components in the hypoxic lung

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00074.2019 ◽

2020 ◽

Vol 318 (1) ◽

pp. L125-L134 ◽

Cited By ~ 2

Author(s):

Sally H. Vitali ◽

Angeles Fernandez-Gonzalez ◽

Janhavi Nadkarni ◽

April Kwong ◽

Chase Rose ◽

...

Keyword(s):

Heme Oxygenase ◽

Acute Hypoxia ◽

Antioxidant Properties ◽

Hypoxic Exposure ◽

Mouse Lung ◽

Heme Oxygenase 1 ◽

Inflammasome Activation ◽

Caspase 1 ◽

Domain 3 ◽

Inflammasome Activity

Exposure to hypoxia causes an inflammatory reaction in the mouse lung, and this response can be modulated by overexpressing the hypoxia-inducible stress-response enzyme, heme oxygenase-1 (HO-1). We hypothesized that the inflammasome activity may be a central pathway by which HO-1 controls pulmonary inflammation following alveolar hypoxia. Therefore, we investigated whether HO-1 controls inflammasome activation by altering its expression in macrophages primed with classic NOD-like receptor containing a pyrin domain 3 (NLRP3) inducers, and in murine lungs lacking HO-1 and exposed to acute hypoxia. We found that lack of HO-1 activated lipopolysaccharide (LPS) and ATP-treated bone marrow-derived macrophages, causing an increase in secreted levels of cleaved interleukin (IL)-1B, IL-18, and caspase-1, markers of increased inflammasome activity, whereas HO-1 overexpression suppressed IL-1B, NLRP3, and IL-18. The production of cleaved IL-1B and the activation of caspase-1 in LPS- and ATP-primed macrophages were inhibited by hemin, an HO-1 inducer, and two HO-1 enzymatic products [bilirubin and carbon monoxide (CO)]. Exposure of mice to hypoxia induced the expression of several inflammasome mRNA components (IL-1B, Nlrp3, and caspase-1), and this was further augmented by HO-1 deficiency. This pronounced inflammasome activation was detected as increased protein levels of apoptosis-associated speck-like protein containing a COOH-terminal caspase recruitment domain, IL-18, procaspase-1, and cleaved caspase-1 in the lungs of hypoxic mice. Systemically, Hmox1-deficient mice showed increased basal levels of IL-18 that were further increased after 48 h of hypoxic exposure. Taken together, these finding point to a pivotal role for HO-1 in the control of baseline and hypoxic inflammasome signaling, perhaps through the antioxidant properties of bilirubin and CO’s pleiotropic effects.

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Exogenous Hydrogen Sulfide Attenuates High Glucose-Induced Cardiotoxicity by Inhibiting NLRP3 Inflammasome Activation by Suppressing TLR4/NF-κB Pathway in H9c2 Cells

Cellular Physiology and Biochemistry ◽

10.1159/000453208 ◽

2016 ◽

Vol 40 (6) ◽

pp. 1578-1590 ◽

Cited By ~ 24

Author(s):

Zena Huang ◽

Xiaodong Zhuang ◽

Chuli Xie ◽

Xun Hu ◽

Xiaobian Dong ◽

...

Keyword(s):

Hydrogen Sulfide ◽

Nlrp3 Inflammasome ◽

High Glucose ◽

Cell Apoptosis ◽

Caspase 3 ◽

Cardiac Cells ◽

Inflammasome Activation ◽

Caspase 1 ◽

Nlrp3 Inflammasome Activation ◽

First Time

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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Characterization of Venoms of Deinagkistrodon acutus and Bungarus multicinctus Using Proteomics and Peptidomics

Current Proteomics ◽

10.2174/1570164617666191121112319 ◽

2020 ◽

Vol 17 (3) ◽

pp. 241-254

Author(s):

Yaqiong Zhang ◽

Zhiping Jia ◽

Yunyang Liu ◽

Xinwen Zhou ◽

Yi Kong

Keyword(s):

Snake Venom ◽

Protein Families ◽

Traditional Medicines ◽

Phospholipases A2 ◽

Inhibitory Peptides ◽

Sds Page ◽

Deinagkistrodon Acutus ◽

Venom Proteins ◽

Proteins And Peptides

Background: Deinagkistrodon acutus (D. acutus) and Bungarus multicinctus (B. multicinctus) as traditional medicines have been used for hundreds of years in China. The venoms of these two species have strong toxicity on the victims. Objective: The objective of this study is to reveal the profile of venom proteins and peptides of D. acutus and B. multicinctus. Method: Ultrafiltration, SDS-PAGE coupled with in-gel tryptic digestion and Liquid Chromatography- Electrospray Ionization-Tandem Mass Spectrometry (LC-ESI-MS/MS) were used to characterize proteins and peptides of venoms of D. acutus and B. multicinctus. Results: In the D. acutus venom, 67 proteins (16 protein families) were identified, and snake venom metalloproteinases (SVMPs, 38.0%) and snake venom C-type lectins (snaclecs, 36.7%) were dominated proteins. In the B. multicinctus venom, 47 proteins (15 protein families) were identified, and three-finger toxins (3FTxs, 36.3%) and Kunitz-type Serine Protease Inhibitors (KSPIs, 32.8%) were major components. In addition, both venoms contained small amounts of other proteins, such as Snake Venom Serine Proteinases (SVSPs), Phospholipases A2 (PLA2s), Cysteine-Rich Secreted Proteins (CRISPs), 5'nucleotidases (5'NUCs), Phospholipases B (PLBs), Phosphodiesterases (PDEs), Phospholipase A2 Inhibitors (PLIs), Dipeptidyl Peptidases IV (DPP IVs), L-amino Acid Oxidases (LAAOs) and Angiotensin-Converting Enzymes (ACEs). Each venom also had its unique proteins, Nerve Growth Factors (NGFs) and Hyaluronidases (HYs) in D. acutus, and Cobra Venom Factors (CVFs) in B. multicinctus. In the peptidomics, 1543 and 250 peptides were identified in the venoms of D. acutus and B. multicinctus, respectively. Some peptides showed high similarity with neuropeptides, ACE inhibitory peptides, Bradykinin- Potentiating Peptides (BPPs), LAAOs and movement related peptides. Conclusion: Characterization of venom proteins and peptides of D. acutus and B. multicinctus will be helpful for the treatment of envenomation and drug discovery.

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Correction for McKenzie et al., Caspase-1 inhibition prevents glial inflammasome activation and pyroptosis in models of multiple sclerosis

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1909025116 ◽

2019 ◽

Vol 116 (26) ◽

pp. 13145-13145

Keyword(s):

Multiple Sclerosis ◽

Inflammasome Activation ◽

Caspase 1

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Jagged1-mediated myeloid Notch1 signaling activates HSF1/Snail and controls NLRP3 inflammasome activation in liver inflammatory injury

Cellular and Molecular Immunology ◽

10.1038/s41423-019-0318-x ◽

2019 ◽

Vol 17 (12) ◽

pp. 1245-1256 ◽

Cited By ~ 7

Author(s):

Yuting Jin ◽

Changyong Li ◽

Dongwei Xu ◽

Jianjun Zhu ◽

Song Wei ◽

...

Keyword(s):

Liver Injury ◽

Inflammatory Response ◽

Immune Cell ◽

Ischemia Reperfusion ◽

Inflammasome Activation ◽

Inflammatory Injury ◽

Notch1 Signaling ◽

Caspase 1 ◽

Hepatocellular Damage ◽

Hepatocellular Apoptosis

AbstractNotch signaling plays important roles in the regulation of immune cell functioning during the inflammatory response. Activation of the innate immune signaling receptor NLRP3 promotes inflammation in injured tissue. However, it remains unknown whether Jagged1 (JAG1)-mediated myeloid Notch1 signaling regulates NLRP3 function in acute liver injury. Here, we report that myeloid Notch1 signaling regulates the NLRP3-driven inflammatory response in ischemia/reperfusion (IR)-induced liver injury. In a mouse model of liver IR injury, Notch1-proficient (Notch1FL/FL) mice receiving recombinant JAG1 showed a reduction in IR-induced liver injury and increased Notch intracellular domain (NICD) and heat shock transcription factor 1 (HSF1) expression, whereas myeloid-specific Notch1 knockout (Notch1M-KO) aggravated hepatocellular damage even with concomitant JAG1 treatment. Compared to JAG1-treated Notch1FL/FL controls, Notch1M-KO mice showed diminished HSF1 and Snail activity but augmented NLRP3/caspase-1 activity in ischemic liver. The disruption of HSF1 reduced Snail activation and enhanced NLRP3 activation, while the adoptive transfer of HSF1-expressing macrophages to Notch1M-KO mice augmented Snail activation and mitigated IR-triggered liver inflammation. Moreover, the knockdown of Snail in JAG1-treated Notch1FL/FL livers worsened hepatocellular functioning, reduced TRX1 expression and increased TXNIP/NLRP3 expression. Ablation of myeloid Notch1 or Snail increased ASK1 activation and hepatocellular apoptosis, whereas the activation of Snail increased TRX1 expression and reduced TXNIP, NLRP3/caspase-1, and ROS production. Our findings demonstrated that JAG1-mediated myeloid Notch1 signaling promotes HSF1 and Snail activation, which in turn inhibits NLRP3 function and hepatocellular apoptosis leading to the alleviation of IR-induced liver injury. Hence, the Notch1/HSF1/Snail signaling axis represents a novel regulator of and a potential therapeutic target for liver inflammatory injury.

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Short Linear Motifs Characterizing Snake Venom and Mammalian Phospholipases A2

Toxins ◽

10.3390/toxins13040290 ◽

2021 ◽

Vol 13 (4) ◽

pp. 290

Author(s):

Caterina Peggion ◽

Fiorella Tonello

Keyword(s):

Snake Venom ◽

Protein Interactions ◽

Biological Properties ◽

Protein Protein Interactions ◽

Sequence Alignments ◽

Toxic Activity ◽

Short Linear Motifs ◽

Phospholipases A2 ◽

Group I ◽

Linear Motifs

Snake venom phospholipases A2 (PLA2s) have sequences and structures very similar to those of mammalian group I and II secretory PLA2s, but they possess many toxic properties, ranging from the inhibition of coagulation to the blockage of nerve transmission, and the induction of muscle necrosis. The biological properties of these proteins are not only due to their enzymatic activity, but also to protein–protein interactions which are still unidentified. Here, we compare sequence alignments of snake venom and mammalian PLA2s, grouped according to their structure and biological activity, looking for differences that can justify their different behavior. This bioinformatics analysis has evidenced three distinct regions, two central and one C-terminal, having amino acid compositions that distinguish the different categories of PLA2s. In these regions, we identified short linear motifs (SLiMs), peptide modules involved in protein–protein interactions, conserved in mammalian and not in snake venom PLA2s, or vice versa. The different content in the SLiMs of snake venom with respect to mammalian PLA2s may result in the formation of protein membrane complexes having a toxic activity, or in the formation of complexes whose activity cannot be blocked due to the lack of switches in the toxic PLA2s, as the motif recognized by the prolyl isomerase Pin1.

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