Long noncoding RNA X-inactive specific transcript regulates NLR family pyrin domain containing 3/caspase-1-mediated pyroptosis in diabetic nephropathy

BACKGROUND NLRP3-mediated pyroptosis is recognized as an essential modulator of renal disease pathology.Long noncoding RNAs(lncRNAs)are active participators of diabetic nephropathy(DN).X inactive specific transcript(XIST)expression has been reported to be elevated in the serum of DN patients.AIM To evaluate the mechanism of lncRNA XIST in renal tubular epithelial cell(RTEC)pyroptosis in DN.METHODS A DN rat model was established through streptozotocin injection,and XIST was knocked down by tail vein injection of the lentivirus LV sh-XIST.Renal metabolic and biochemical indices were detected,and pathological changes in the renal tissue were assessed.The expression of indicators related to inflammation and pyroptosis was also detected.High glucose(HG)was used to treat HK2 cells,and cell viability and lactate dehydrogenase(LDH)activity were detected after silencing XIST.The subcellular localization and downstream mechanism of XIST were investigated.Finally,a rescue experiment was carried out to verify that XIST regulates NLR family pyrin domain containing 3(NLRP3)/caspase-1-mediated RTEC pyroptosis through the microRNA-15-5p(miR-15b-5p)/Toll-like receptor 4(TLR4)axis.RESULTS XIST was highly expressed in the DN models.XIST silencing improved renal metabolism and biochemical indices and mitigated renal injury.The expression of inflammation and pyroptosis indicators was significantly increased in DN rats and HG-treated HK2 cells;cell viability was decreased and LDH activity was increased after HGtreatment. Silencing XIST inhibited RTEC pyroptosis by inhibiting NLRP3/caspase-1. Mechanistically,XIST sponged miR-15b-5p to regulate TLR4. Silencing XIST inhibited TLR4 by promotingmiR-15b-5p. miR-15b-5p inhibition or TLR4 overexpression averted the inhibitory effect ofsilencing XIST on HG-induced RTEC pyroptosis.CONCLUSIONSilencing XIST inhibits TLR4 by upregulating miR-15b-5p and ultimately inhibits renal injury inDN by inhibiting NLRP3/caspase-1-mediated RTEC pyroptosis.

Therapeutic interventions target the NLRP3 inflammasome in ulcerative colitis:Comprehensive study

One of the significant health issues in the world is the prevalence of ulcerative colitis(UC).UC is a chronic disorder that mainly affects the colon,beginning with the rectum,and can progress from asymptomatic mild inflammation to extensive inflammation of the entire colon.Understanding the underlying molecular mechanisms of UC pathogenesis emphasizes the need for innovative therapeutic approaches based on identifying molecular targets.Interestingly,in response to cellular injury,the NLR family pyrin domain containing 3(NLRP3)inflammasome is a crucial part of the inflammation and immunological reaction by promoting caspase-1 activation and the release of interleukin-1β.This review discusses the mechanisms of NLRP3 inflammasome activation by various signals and its regulation and impact on UC.

Effect and mechanism of reactive oxygen species-mediated NOD-like receptor family pyrin domain-containing 3 inflammasome activation in hepatic alveolar echinococcosis

BACKGROUND The NOD-like receptor family pyrin domain-containing 3(NLRP3)inflammasome is a significant component of the innate immune system that plays a vital role in the development of various parasitic diseases.However,its role in hepatic alveolar echinococcosis(HAE)remains unclear.AIM To investigate the NLRP3 inflammasome and its mechanism of activation in HAE.METHODS We assessed the expression of NLRP3,caspase-1,interleukin(IL)-1β,and IL-18 in the marginal zone and corresponding normal liver of 60 patients with HAE.A rat model of HAE was employed to investigate the role of the NLRP3 inflammasome in the marginal zone of HAE.Transwell experiments were conducted to investigate the effect of Echinococcus multilocularis(E.multilocularis)in stimulating Kupffer cells and hepatocytes.Furthermore,immunohistochemistry,Western blotting,and enzyme-linked immunosorbent assay were used to evaluate NLRP3,caspase-1,IL-1β,and IL-18 expression;flow cytometry was used to detect apoptosis and reactive oxygen species(ROS).RESULTS NLRP3 inflammasome activation was significantly associated with ROS.Inhibition of ROS production decreased NLRP3-caspase-1-IL-1βpathway activation and mitigated hepatocyte damage and inflammation.CONCLUSION E.multilocularis induces hepatocyte damage and inflammation by activating the ROS-mediated NLRP3-caspase-1-IL-1βpathway in Kupffer cells,indicating that ROS may serve as a potential target for the treatment of HAE.

Involvement of NLRP3-inflammasome pathway in noise-induced hearing loss

The inflammasome is a multiprotein oligomer in the cell cytoplasm and is part of the innate immune system.It plays a crucial role in the pathological process of noise-induced hearing loss(NIHL).However,the mechanisms of NLR family pyrin domain containing 3(NLRP3)inflammasome activation in NIHL have not been clearly demonstrated.In this study,miniature pigs were exposed to white noise at 120 dB(A)and auditory brainstem response measurements were used to measure their hearing function.Immunofluorescence staining,confocal laser scanning microscopy,western blot assay,and quantitative reverse transcription-polymerase chain reaction were used to analyze inflammasome-related protein distribution and expression.NLRP3,interleukin-1β,interleukin-18,and cleaved-caspase-1 were highly expressed in the cochlea after 120 dB(A)white noise exposure.Our findings suggest that NLRP3-inflammasomes in the cochlea may be activated after acoustic trauma,which may be an important mechanism of noise-induced hearing loss.

Immune response modulation in inflammatory bowel diseases by Helicobacter pylori infection

Many studies point to an association between Helicobacter pylori(H.pylori)infection and inflammatory bowel diseases(IBD).Although controversial,this association indicates that the presence of the bacterium somehow affects the course of IBD.It appears that H.pylori infection influences IBD through changes in the diversity of the gut microbiota,and hence in local chemical characteristics,and alteration in the pattern of gut immune response.The gut immune response appears to be modulated by H.pylori infection towards a less aggressive inflammatory response and the establishment of a targeted response to tissue repair.Therefore,a T helper 2(Th2)/macrophage M2 response is stimulated,while the Th1/macrophage M1 response is suppressed.The immunomodulation appears to be associated with intrinsic factors of the bacteria,such as virulence factors-such oncogenic protein cytotoxin-associated antigen A,proteins such H.pylori neutrophil-activating protein,but also with microenvironmental changes that favor permanence of H.pylori in the stomach.These changes include the increase of gastric mucosal pH by urease activity,and suppression of the stomach immune response promoted by evasion mechanisms of the bacterium.Furthermore,there is a causal relationship between H.pylori infection and components of the innate immunity such as the NLR family pyrin domain containing 3 inflammasome that directs IBD toward a better prognosis.

Ginsenoside Rb1 Reduces D-GalN/LPS-induced Acute Liver Injury by Regulating TLR4/NF-κB Signaling and NLRP3 Inflammasome

Background and Aims:The effect of ginsenoside Rb1 on D-galactosamine(D-GalN)/lipopolysaccharide(LPS)-induced acute liver injury(ALI)is unknown.The aim of this study was to evaluate the effect of ginsenoside Rb1 on ALI and its underlying mechanisms.Methods:Mice were pretreated with ginsenoside Rb1 by intraperitoneal injection for 3 days before D-GalN/LPS treatment,to induce ALI.The survival rate was monitored every hour for 24 h,and serum biochemical parameters,hepatic index and histopathological analysis were evaluated to measure the degree of liver injury.ELISA was used to detect oxidative stress and inflammatory cytokines in hepatic tissue and serum.Immunohistochemistry staining,RT-PCR and western blotting were performed to evaluate the expression of toll-like receptor 4(TLR4),nuclear factorkappa B(NF-κB),and NLR family,pyrin domain-containing 3 protein(NLRP3)in liver tissue and Kupffer cells(KCs).Results:Ginsenoside Rb1 improved survival with D-GalN/LPS-induced ALI by up to 80%,significantly ameliorated the increased alanine and aspartate transaminase,restored the hepatic pathological changes and reduced the levels of oxidative stress and inflammatory cytokines altered by D-GalN/LPS.Compared to the control group,the KCs were increased in the D-GalN/LPS groups but did not increase significantly with Rb1 pretreatment.D-GalN/LPS could upregulate while Rb1 pretreatment could downregulate the expression of interleukin(IL)-1β,IL-18,NLRP3,apoptosis associated specklike protein containing CARD(ASC)and caspase-1 in isolated KCs.Furthermore,ginsenoside Rb1 inhibited activation of the TLR4/NF-κB signaling pathway and NLRP3 inflammasome induced by D-GalN/LPS administration.Conclusions:Ginsenoside Rb1 protects mice against D-GalN/LPS-induced ALI by attenuating oxidative stress and the inflammatory response through the TLR4/NF-κB signaling pathway and NLRP3 inflammasome activation.

Qingre Jianpi decoction(清热健脾汤)attenuates inflammatory responses by suppressing NOD-like receptor family pyrin domain-containing 3 inflammasome activation in dextran sulfate sodium-induced colitis mice

OBJECTIVE:To investigate the effects of Qingre Jianpi decoction(清热健脾汤,QRJPD)on dextran sulfate sodium(DSS)-induced colitis mice and explore its mechanism.METHODS:All mice were randomly divided into six groups.Weight changes,disease activity index values,and histological damage were detected.Inflammatory cytokines and immune cell infiltration were measured using enzyme-linked immunosorbent assays(ELISA)and immunohistochemistry(IHC)method.The key protein expression levels of the NOD-like receptor family pyrin domain-containing 3(NLRP3)inflammasome were detected by western blot analysis,IHC,and quantitative reverse transcription polymerase chain reaction.RESULTS:QRJPD played an anti-inflammatory role in the treatment of ulcerative colitis(UC),reduced the secretion of inflammatory cytokines,and inhibited the inflammatory infiltration of immune cells by suppressing DSS-induced activation of the NLRP3 inflammasome.CONCLUSION:QRJPD exerts protective effects by inhibiting DSS-induced NLRP3 inflammasome activation.

AstragalosideⅣplays a role in reducing radiation-induced liver inflammation in mice by inhibiting thioredoxin-interacting protein/nod-like receptor protein 3 signaling pathway

OBJECTIVE:To investigate the efficacy of Astragaloside IV(AS-IV)on radiation-induced liver inflammation in mice.METHODS:The mice were divided into normal group,dimethyl sulfoxide solvent group,irradiation group(IR),irradiation+AS-IV(20 mg/kg)group(IR+AS-20)and irradiation+AS-IV(40 mg/kg)group(IR+AS-40).One month after intraperitoneal injection of AS-IV,the mice were irradiated with 8Gry Co60γ,the blood was collected for biochemical analysis,and the liver was collected for hematoxylin-eosin staining,immunofluorescence and electron microscopic observation,oxidative stress,and Western blot analysis.RESULTS:The AS-IV treatment significantly ameliorated the pathological morphology of liver and reduced the alanine aminotransferase and aspertate aminotransferase levels in serum induced by radiation;AS-IV treatment also significantly reduced the expression of inflammatory factors tumor necrosis factor alpha and interleukin 6 and antagonized malonaldehyde content and superoxide dismutase activity in liver caused by radiation;in addition,AS-IV treatment can significantly inhibited the positive expression of thioredoxin-interacting protein(TXNIP)and nod-like receptor protein 3(NLRP3)inflammasome in liver tissue after radiation;The expression of TXNIP,NLRP3 inflammasome,apoptosisassociated speck-like protein containing a CARD,cysteinyl aspartate-specific proteinase 1 and interleukin 1beta in the AS-IV prevention group decreased significantly compared to the radiation group.CONCLUSIONS:These findings suggested that Co60γradiation can cause structural and functional damage to the liver,which may be related to the NLRP3 mediated inflammatory pathway;AS-IV may play a protective role by inhibiting the TXNIP/NLRP3 inflammasome signaling pathway in the radiation-induced liver injury model.

Qingchi San(青赤散)treats ulcerative colitis in mice by inhibiting the nuclear factor-kappa B signaling pathway and Nucleotide-binding oligomerization domain,leucine-rich repeat and pyrin domain-containing 3 inflammasome formation

OBJECTIVE:To investigate the efficacy of Qingchi San(青赤散,QCS),a preparation of Traditional Chinese Medicine,on ulcerative colitis(UC)in mice by inhibiting the nuclearfactor-kappa B(NF-κB)signaling pathway and nucleotide-binding oligomerization domain,leucine-rich repeat and pyrin domain-containing 3(NLRP3)inflammasome formation.METHODS:The UC model was established with male C57BL/6J as the animal model.Bodyweight,Disease Activity Index(DAI),colon length and weight were detected.Furthermore,colonic histology was performed by hematoxylin-eosin(HE)staining.interleukin-1β(IL-1β),interleukin-6(IL-6),tumor necrosis factor-α(TNF-α),myeloperoxidase(MPO)and superoxide dismutase(SOD)were performed by enzyme-linked immunosorbent assay.Cyclooxygenase 2(COX2)and inducible nitric oxide synthase(iNOS)mRNA expression were conducted by real-time quantitative polymerase chain reaction(RT-qPCR).NF-κB,inhibitor of NF-κBα(iκBα),Phosphorylated inhibitor of NF-κBα(p-iκBα),caspase-1,NLRP3 and Apoptosis-associated speck-like protein containing a caspase recruitment domain(ASC)protein expression were conducted by Western blotting.RESULTS:Compared with UC model group,Bodyweight was significantly increased in QCS treatment.At the same time,DAI was significantly decreased in QCS treatment.Colon length and weight and colonic histology were significantly improved in QCS treatment.Furthermore,the expression of IL-1β,IL-6,TNF-α,MPO,SOD,COX2,and iN OS were significantly decreased in QCS treatment.Finally,the expression of NF-κB signaling pathway-related proteins NF-κB,iκBα,p-iκBα,and the expression of NLRP3 inflammasome related proteins caspase-1,NLRP3 and ASC were significantly decreased in QCS treatment.CONCLUSION:Traditional Chinese drug QCS could treat UC by inhibiting the NF-κB signaling pathway and NLRP3 inflammasome formation in mice.

Reduning plus ribavirin display synergistic activity against severe pneumonia induced by H1N1 influenza A virus in mice

OBJECTIVE:To investigate synergistic effect of Reduning(RDN)injection plus ribavirin against severe pneumonia induced by H1 N1 influenza A virus in mice.METHODS:We established a mouse model of severe pneumonia induced by influenza A virus by infecting Balb/c mice with CA07 virus.We randomly assigned the infected mice into four groups,and treated them with normal saline(NS group),RDN(injection,86.6 mg/kg),ribavirin(injection,66.6 mg/kg)or double Ribavirin plus RDN group,the same dosage as used in the single treatments)for 5 d.Lung index and lung pathology were recorded or calculated in terms of the curative effective.Cytokines,NOD-like receptor family pyrin domain containing 3(NLRP3)inflammasome related protein including caspase-associated recruitment domain(CARD)domain Apoptosis-associated speck-like protein containing a caspase recruitment domain(ASC),caspase-1 and NOD-like receptor family,pyrin domain containing 3(NLRP3),and reactive oxygen species were simultaneously investigated.RESULTS:RDN plus ribavirin treatment,not RDN or ribavirin alone,provided a significant survival benefit to the influenza A virus-infected mice.The combination treatment protected the mice against severe influenza infection by attenuating the severe lung injury.The combined treatment also reduced the viral titers in mouse lungs and lung index,downregulated their immunocytokine levels,including IL-1βand IL-18,and down regulated the NLRP3,especially the transcription and translation of caspase-1.Meanwhile NS group had significantly higher reactive oxygen species(ROS)expression which could was dramatically reduced by the treatment of RDN plus ribavirin.CONCLUSION:Our study showed that RDN combined with ribavirin could protect the mice,and reduce the lung immunopathologic damage caused by severe influenza pneumonia.The mechanism could be that it reduced ROS produce and inhibited NLRP3 inflammasome activation so that mainly lower the downstream inflammatory cytokines IL-1βand IL-18.

Sini powder ameliorates the inflammatory response in rats with stress-induced non-alcoholic fatty liver disease by inhibiting the nuclear factor kappa-B/pyrin domain-containing protein 3 pathway

OBJECTIVE: To evaluate the effectiveness of Sini powder for the treatment of non-alcoholic fatty liver disease(NAFLD) in rats and the molecular mechanisms involved.METHODS: A rat model of stress-induced NAFLD was established by a combination of long-term tethering and feeding of a high-fat, high-calorie diet. These rats were then intragastrically administered with either simvastatin, Sini powder, or vehicle for 1 week. The body mass and field test scores for each group were recorded weekly. Serum aspartate aminotransferase and alanine aminotransferase activities, and triglyceride, total cholesterol,and free fatty acid concentrations were measured.Liver tissue histopathology was examined on hematoxylin and eosin-stained paraffin sections and oil red O-stained frozen sections. The hepatic m RNA expression of nuclear factor kappa-B(NF-κB),NOD-, LRR-, and pyrin domain-containing protein 3(NLRP3), apoptosis-associated speck-like protein containing CARD(ASC), and caspase-1 were measured by reverse transcription-polymerase chain reaction(RT-PCR). The hepatic protein concentrations of NF-κB and NLRP3, ASC, caspase-1, interleukin-1β(IL-1β), interleukin-6(IL-6), and the serum concentrations of IL-1β and IL-6 were measured by enzyme-linked immunosorbent assay.RESULTS: Compared with the Blank group, rats in the Compound model group showed significant pathologic manifestations of NAFLD, and the expression of NF-κB, NLRP3, ASC, caspase-1, IL-1βand IL-6 were significantly higher(all P < 0.01). Both simvastatin and Sini powder significantly ameliorated the NAFLD pathology and the abnormal expression of NF-κB, NLRP3, ASC, caspase-1, IL-1β, and IL-6(all P < 0.01).CONCLUSION: Sini powder inhibits the inflamma-tory response in rats with NAFLD, which is mediated by NF-κB/NLRP3, IL-1β, and IL-6, reduces the effects of psychological stress, and improves lipid metabolism. Therefore, Sini powder may be effective for the treatment of stress-related NAFLD through multiple mechanisms.

Effect of electroacupuncture on inflammatory signal expression in local tissues of rats with chronic pelvic pain syndrome based on purinergic 2X7 receptor/NOD-like receptor pyrin domaincontaining 3 signal pathway

OBJECTIVES: To study the expression of inflammatory signal in local prostate tissue of chronic pelvic pain syndrome(CPPS) rats by electroacupuncture(EA) of Guanyuan(CV4), Zhongji(CV3), Huiyang(BL35) and Sanyinjiao(SP6), and to explore the possible mechanism of anti-inflammatory and analgesic effects of EA. METHODS : A total of 36 Sprague-Dawley male rats were randomly divided into three groups: control, model and EA(n=12 rats/group). The CPPS model was made by injection of CFA into ventral lobes of the prostate(0.1 m L). Electric acupuncture apparatus was applied to stimulate Guanyuan(CV4), Zhongji(CV3), bilateral Huiyang(BL35) and Sanyinjiao(SP6) acupoints in EA group. The general condition of rats was observed and the prostate index(PI) was calculated. The thermal pain threshold was collected after each therapeutic course. Histopathological changes of the prostate tissue were examined by hematoxylin-eosin staining method. The expression levels of tumor necrosis factor α(TNF-α), interleukin-1β(IL-1β) and prostaglandin E2(PGE2) in prostatic homogenates were measured by enzyme linked immunosorbent assay(ELISA). Moreover, the expression levels of purinergic 2X7 receptor(P2X7R), NOD-like receptor pyrin domain-containing 3(NLRP3), caspase-1 and interleukin-18(IL-18) m RNA were quantified by quantitative real-time polymerase chain reaction. RESULTS: Compared with control group, the PI of rats increased, and the thermal pain threshold decreased significantly in model group. The morphological structure of prostate tissues of rats in model group was severely damaged with a large number of inflammatory cells infiltration. Additionally, the levels of TNF-α, IL-1β and PGE2 were higher, and the expressions of P2X7R, NLRP3, caspase-1 and IL-18 m RNA were higher than those in control group. After EA treatment, the PI was significantly decreased, the thermal pain threshold was significantly increased, and the tissue damage was significantly improved. The expressions of inflammatory cytokines were lower in EA group, and expression of P2X7R/NLRP3 pathway was down-regulated. CONCLUSION: The effect of EA at Guanyuan(CV4), Zhongji(CV3), Huiyang(BL35) and Sanyinjiao(SP6) can improve inflammation and pain symptoms of CPPS rats induced by Complete Freund’s adjuvant(CFA). This suggests that EA at Guanyuan(CV4), Zhongji(CV3), Huiyang(BL35) and Sanyinjiao(SP6) can produce antiinflammatory analgesia effect by preventing the activation of P2X7R/NLRP3 signal pathway, inhibit the release of inflammatory cytokines in CPPS rats, which may provide a putative novel target for the treatment of CPPS.