Interleukin-1 receptor-associated kinase-2 is involved in IL-18-induced NF-κB activation

objective: To investigate whether interleukin-1 receptor-associated kinase-2 (IRAK-2) is involved in interleukin-18 (IL-18)-induced nuclear factor- κ B (NF-κ B) activation. Methods: Phosphorothioate oligodeoxynucleotide (ODN) was designed antisense to sequences of IRAK-2. Antisense IRAK-2 ODN was delivered by lipofectin encapsulation into cultured HepG2 cells. IRAK-2 mRNA expression was assayed by semiquantitative reverse transcription-PCR. The levels of NF- K B were measured by sandwich ELISA. Results: Antisense IRAK-2 ODN blocked IRAK -2expression. IL-18 activated NT- K B and the A value increased from a basal level of 0.115±0.004 to 2.141 ±0.038. Antisense IRAK-2 ODN inhibited IL-18-induced NT- K B activation in a dose (1-8μg )-dependent fashion. When the cells were treated with 4μg antisense IRAK-2 ODN for 8 h, a maximum inhibition of 45.4% was induced as shown by the reduction of the OD value from a control level of 2.141±0.038 down to 1.168±0.026. Conclusion: IRAK-2 can regulate IL-18-stimulated NF- K B activation.

Interleukin-1 receptor associated kinase 2 is a functional downstream regulator of complement factor D that controls mitochondrial fitness in diabetic cardiomyopathy

Diabetic cardiomyopathy is a disorder of the cardiac muscle that affects patients with diabetes.The exact mechanisms underlying diabetic cardiomyopathy are mostly unknown,but several factors have been implicated in the pathogenesis of the disease and its progression towards heart failure,including endothelial dysfunction,autonomic neuropathy,metabolic alterations,oxidative stress,and alterations in ion homeostasis,especially calcium transients[1].In Military Medical Research,Jiang et al.[2]sought to determine the functional role of complement factor D(Adipsin)in the pathophysiology of diabetic cardiomyopathy.

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.