Small extracellular vesicles from hypoxia-preconditioned bone marrow mesenchymal stem cells attenuate spinal cord injury via miR-146a-5p-mediated regulation of macrophage polarization

Spinal cord injury is a disabling condition with limited treatment options.Multiple studies have provided evidence suggesting that small extracellular vesicles(SEVs)secreted by bone marrow mesenchymal stem cells(MSCs)help mediate the beneficial effects conferred by MSC transplantation following spinal cord injury.Strikingly,hypoxia-preconditioned bone marrow mesenchymal stem cell-derived SEVs(HSEVs)exhibit increased therapeutic potency.We thus explored the role of HSEVs in macrophage immune regulation after spinal cord injury in rats and their significance in spinal cord repair.SEVs or HSEVs were isolated from bone marrow MSC supernatants by density gradient ultracentrifugation.HSEV administration to rats via tail vein injection after spinal cord injury reduced the lesion area and attenuated spinal cord inflammation.HSEVs regulate macrophage polarization towards the M2 phenotype in vivo and in vitro.Micro RNA sequencing and bioinformatics analyses of SEVs and HSEVs revealed that mi R-146a-5p is a potent mediator of macrophage polarization that targets interleukin-1 receptor-associated kinase 1.Reducing mi R-146a-5p expression in HSEVs partially attenuated macrophage polarization.Our data suggest that HSEVs attenuate spinal cord inflammation and injury in rats by transporting mi R-146a-5p,which alters macrophage polarization.This study provides new insights into the application of HSEVs as a therapeutic tool for spinal cord injury.

Efficacy of Sishen Wan(四神丸) on dinitrobenzene sulfonic acid-induced ulcerative colitis and its effect on toll-like receptor 2/interleukin-1 receptor-associated kinase-4/nuclear factor-κB signal pathway

OBJECTIVE:To investigate the therapeutic effect of Sishen Wan(四神丸,SSW)on ulcerative colitis(UC)induced by dinitrobenzene sulfonic acid and its effect on toll-like receptor 2/interleukin-1 receptor-associated kinase-4/nuclear factor-κB(TLR2/IRAK4/NF-κB)signaling pathway in colonic tissue.METHODS:In this study,120 Sprague–Dawley rats were randomly divided into blank and model groups.The experimental UC model in rats was established by subcutaneous injection of hydrocortisone+senna gavage for 21 d+dinitrobenzene sulfonic acid(DNBS)/ethanol solution enema.The successful model rats were randomly divided into the model group;mesalazine(0.36 g/kg)group;and high-,medium-,and low-dose SSW(24,12,and 6 g/kg)groups.The model and blank groups were gavaged with equal volumes of distilled water once a day for 21 d.The general condition of the rats was observed,and the body mass,fecal properties,and occult blood were recorded for calculating the disease activity index(DAI)score.The colonic tissue of the rats was collected,and its general morphology and pathological form were noted for obtaining the colonic mucosal injury index(CMDI)score.Hematoxylin-eosin staining was used to view the pathological changes of the colon tissue in each group,apoptosis of the cells was detected using terminal deoxynucleotidyl transferase-mediated d UTP nick-end labeling staining,and quantitative real-time polymerase chain reaction was used to measure the expressions of TLR2,myeloid differentiation primary response gene 88(My D88),IRAK4,and NF-κB p65 mRNA in the colon tissue.The expressions of TLR2,My D88,IRAK4,and NF-κB p65 protein were detected using western blotting and immunohistochemistry assay,and the levels of interleukin-1β(IL-1β)and tumor necrosis factor-α(TNF-α)in the colon tissue were determined using enzyme linked immunosorbent assay.RESULTS:Compared with the blank group,the general condition of the model group was relatively poor.The DAI and CMDI scores of the model group increased significantly(P<0.01),the glands and intestinal mucosa disappeared partially,and several inflammatory cells infiltrated and gathered in the mucosal layer and base layer of the rats in the model group.Furthermore,the cell apoptosis and expression levels of TLR2,My D88,IRAK4,and NF-κB p65 mRNA and protein in the colon tissue of rats in the model group increased significantly(P<0.01).The levels of IL-1βand TNF-αincreased significantly in the colon tissue of rats in the model group(P<0.01).After treatment with SSW,compared with the model group,the general condition of the UC rats improved.Moreover,the DAI and CMDI scores of the UC rats decreased significantly(P<0.05),and the pathological changes in the colon tissue of the UC rats tended to be normal.The cell apoptosis and expression levels of TLR2,My D88,IRAK4,and NF-κB p65 mRNA and protein in the colon tissue of the UC rats decreased gradually(P<0.01),and the levels of IL-1βand TNF-αdecreased significantly(P<0.01).CONCLUSION:SSW can improve the general condition and alleviate the intestinal mucosal injury of UC model rats.Additionally,SSW can inhibit the TLR2/IRAK4/NF-κB signaling pathway,but further studies are required to confirm it.

Different effects of antisense IRAK-2 oligonucleotide on IL-1 and TNF-stimulated NF-kappa B activation

Objective: To investigate the role of interleukin-1 (IL-1) receptor associated kinase-2 (IRAK-2) in IL1 and TNF-stimulated nuclear factor-kappa B (NF-kappa B ) activation. Metbods: The 293 cell was trans fectedwith antisense IRAK-2 oligonucleotide (IRAK-2 ODN) followed by stimulating the cell with IL-1 or tumor necrosis factor (TNF), and then the levels of NF-kappa B activation was analyzed by sandwich enzyme-linked immunosorbent assay (ELISA ). Result: Pre-transfecting with antisense IRAK-2 ODN could remarkably decreasethe levels of NF-kappa B activation stimulated by IL-1 in time- and concentration-dependent manner, it can not attenuate the one stimulated by TNF. Conclusion: The responses of IL-1 and TNF-stimulated NF-kappa B activation to antisense IRAK-2 oligonucleotids were different. IRAK-2 plays a key role in the IL-1 signaling events leading to NF kappa B activation.

Study on effect of imbalance of TRAF-6, IRAK-1 and NALP3 inflammatory factors in patients with gouty arthritis

Objective:To explore the effect of imbalance of tumor necrosis factor receptor related factor-6(TRAF-6),interleukin 1 receptor associated kinase-1(IRAK-1)and neutrophil alkaline phosphatase-3(NALP3)in patients with gouty arthritis.Methods:The retrospective experiment was conducted on 105 patients with gouty arthritis admitted to our hospital(47 patients with acute onset and 58 patients with remission,namely group A and group B);meanwhile,another 61 healthy volunteers were selected for control,namely group C.The enrolling of the three groups was dated from May 2017 to May 2018,and TRAF-6,IRAK-1 and NALP3 of all subjects were tested through real-time fluorescence quantification(RT-PCR),and the correlation between the three inflammatory factors and gouty arthritis was compared.Results:1)Through treatment,ESR,BUA and total addiment in group A and B were higher than those in group C,among which the three indicators in group A were higher than those in group B(P<0.05),while CRP was lower than that of group C,and the two indicators in group A were lower than those in group B(P<0.05).2)There was no significant difference in the relative expression of TRAF-6 mRNA between group A and group B before treatment(P>0.05),significantly lower than group C(P<0.05);the above indicators of group A and group B were improved to some extent after treatment,but group A was still lower than group B(P<0.05),and the degree of improvement of group A was also lower than that of group C(P<0.05),while the degree of improvement of group B was not significantly different from that of group C(P>0.05).3)The relative expression level of IRAK-1mRNA in group A and group B before treatment showed no significant difference(P>0.05),but was also lower than that in group C(P<0.05).The relative expression level of IRAK-1mRNA in group A and group B increased to some extent after treatment,with group A significantly lower than group C(P<0.05),and group B showed no significant difference compared with group C(P>0.05).4)The relative expression level of NALP-3 mRNA in group A and group B showed no significant difference(P>0.05)before treatment,significantly higher than that in group C(P<0.05);the relative expression of NALP-3 mRNA in group A was not significantly decreased(P>0.05)after treatment,while that in group B was significantly decreased after treatment(P<0.05),indicating significant different compared with group A and group C.5)There was no correlation between)TRAF-6,ESR,CRP and total addiment(P>0.05);IRAK-1 was negatively correlated with CRP,BUA and total addiment(P<0.05);NALP-3 was negatively correlated with ESR and CRP(P<0.05).Conclusion:TRAF-6,IRAK-1 and NALP-3 are all under abnormal expression in the developing of new gouty arthritis,acting as important participants in promoting the occurrence,development and outcome of illness states,so the intervening measures should be taken.

Functional polymorphism in exon 5 and variant haplotype of the interleukin-1 receptor-associated kinase 1 gene are associated with susceptibility to and severity of sepsis in the Chinese population

Background The interleukin-1 （IL-1） receptor-associated kinase 1 （IRAK1） is believed to play an important role in the pathogenesis of sepsis. Recent studies have suggested that the I RAK1 functional genetic variant could affect the severity of sepsis in Caucasians. In this report, we have investigated whether polymorphisms at the IRAK1 gene are associated with the susceptibility to and severity of sepsis among the Chinese population. Methods Haplotype-tagging single nucleotide polymorphisms （htSNPs） were selected from the HapMap database. They.were genotyped in 255 patients with sepsis and 260 control subjects by PCR/restriction fragment length polymorphism （RFLP） analysis. The association between the selected htSNPs and the susceptibility to and severity of sepsis were estimated by Logistic regression with adjustments for age, sex, smoking, drinking, chronic disease status, Acute Physiology and Chronic Health Evaluation （APACHE） II score and primary diseases. Results rs1059702 was selected to represent the six linked htSNPs for IRAKI. Genotype frequencies of the htSNPs were in Hardy-Weinberg equilibrium for females, as were allele frequencies for both sex groups. Associations were observed in females between the htSNPs C/C genotype and increased susceptibility to sepsis （odds ratio （OR）, 5.46; 95% confidence interval （C/）, 1.12-26.67; P=0.018）, and such associations were also observed between the IRAK1 variant haplotype （CC/C-allele） and increased susceptibility to sepsis （OR, 1.68; 95% C/, 1.05-2.70; P=0.031） when compared with the T/T ＋ T/C genotype and the wild-type haplotype （TC ＋ TT/T-allele）. In the multiple organ dysfunction syndrome （MODS） subgroup, the variant haplotype was also associated with increased severity of sepsis （OR, 2.37; 95% Cl, 1.13-4.94; P=-0.02） when compared with the wild haplotype. This association was not significant in male patients. Conclusions The functional polymorphism in exon 5 and the variant haplotype of IRAK1 gene mediate susceptibility to and severity of sepsis. IRAK1 might be a genetic risk factor for the occurrence and development of sepsis in the Chinese population.

Protective Effect of Diallyl Trisulfide on Liver in Rats with Sepsis and the Mechanism

The protective effects of diallyl trisulfide on liver were examined in rats with sepsis. Sepsis was reproduced in rats by cecum ligation and puncture (CLP). Fifty-six male Wistar rats were randomly divided into sham-operated group (group S, n=8), sepsis model group (group C, n=24), diallyl trisulfide (DATS)-treated group (group D, n=24). Animals in groups C and D were further divided into three subgroups according to different observation time points, with 8 rats in each sub-group.Rats in group D and C were intravenously injected with normal saline or DATS respectively at a dose of 20 mg/kg after the establishment of sepsis model. Eight rats in groups C and D were sacrificed at 3, 6 and 24 h post-CLP and their livers were harvested for detection of interleukin (IL)-1 receptor associated kinase-4 (IRAK-4), nuclear factor-κB (NF-κB), c-fos, c-jun, malondialdehydethhe (MDA) and superoxide dismutase (SOD), tumor necrosis factor alpha (TNF-α) and for pathological examination. The results showed that the levels of serum IRAK-4, NF-κB and TNF-α in hepatic tissues were higher in group C than group S (control group) (P<0.05). After DATS treatment, the levels of IRAK-4 and NF-κB in the hepatic tissues and serum TNF-α in group D were lower than those in group C (P<0.05). The levels of c-fos and c-jun and MDA in the hepatic tissues were higher in group C than in group S (P<0.05). After DATS treatment, the levels of c-fos and c-jun and MDA in the hepatic tissues were significantly lower in group D than in group C (P<0.05). When compared with group S group, concentration of SOD in the hepatic tissues in group C was significantly lower (P<0.05). After DATS treatment, the concentration of SOD in the hepatic tissues was higher in group D than in group C (P<0.05). These findings suggested that treatment with DATS could ameliorate sepsis-induced liver injury in rats. The protective effect might be related to its ability to inhibit the signal pathway of IRAK-4 and NF-κB, thereby decreasing the production of oxygen free radicals and down-regulating the expression of c-fos and c-jun.

Celastrol targets IRAKs to block Toll-like receptor 4-mediated nuclear factor-κB activation

OBJECTIVE： Celastrol has been established as a nuclear factor-κB（NF-κB） activation inhibitor; however, the exact mechanism behind this action is still unknown. Using text-mining technology, the authors predicted that int erleukin-1 receptor-associated kinases（IRA Ks） are potential celastrol targets, and hypothesized that targeting IRAKs might be one way that celastrol inhibits NF-κB. This is because IRAKs are key molecules for some crucial pathways to activate NF-κB（e.g., the inter leukin-1 receptor（IL-1R）/Toll- like receptor（TLR） superfamily）.METHODS： The human hepatocellular cell line（Hep G2） treated with palmitic acid（PA） was used as a model for stimulating TLR4/NF-κB activation, in order to observe the potential effects of celastrol in IRAK regulation and NF-κB inhibition. The transfection of small interfering RNA was used for down-regulating TLR4, IRAK1 and IRAK4, and the Western blot method was used to detect changes in the protein expressions.RESULTS： The results showed that celastrol could effectively inhibit PA-caused TLR4-dependent NF-κB activation in the Hep G 2 cells; PA also activated IRAKs, which were inhibited by celastrol. Knocking down IRAKs abolished PA-caused NF-κB activation.CONCLUSION： The results for the first time show that targeting IRAKs is one way in which celastrol inhibits NF-κB activation.