Objective To analyze the association of variants of hepatocyte nuclear factor-1α （HNF-1α） gene with type 2 diabetes in Chinese population. Methods In 152 unrelated type 2 diabetes patients and 93 unrelated control...Objective To analyze the association of variants of hepatocyte nuclear factor-1α （HNF-1α） gene with type 2 diabetes in Chinese population. Methods In 152 unrelated type 2 diabetes patients and 93 unrelated controls, eleven single nucleotide polymorphisms （SNPs） were identified and genotyped. Statistical analyses were performed to investigate whether these SNPs were associated with diabetes status in our samples. Results In the individual SNP study, no SNP differed significantly in frequency between type 2 diabetes patients and controls. In the haplotype analysis, two haplotype blocks were identified. In haplotype block 1, no evidence was found between common HNF-1α haplotypes and type 2 diabetes. However, in haplotype block 2, a common haplotype GCGC formed by four tagging SNPs （tSNPs） was found to be associated with decreased risk of type 2 diabetes （odds ratio [OR] 0.6011, 95% confidence interval [CI] 0.4138-0.8732, P=0.0073, empirical P=0.0511, permutation test）. A similar trend was also observed in the diplotype analysis, indicating that the increasing copy number of the haplotype GCGC was associated with the decreased frequency of diabetes （P=0.0193）. Conclusion The results of this study provide evidence that the haplotype of HNF-1α decreases the risk of type 2 diabetes in Chinese individuals.展开更多
AIM: To explore the roles of microRNA-let7 c(miR-let7 c) and transforming growth factor-β2(TGF-β2) and cellular signaling during epithelial-to-mesenchymal transition(EMT) of retinal pigment epithelial cells. METHODS...AIM: To explore the roles of microRNA-let7 c(miR-let7 c) and transforming growth factor-β2(TGF-β2) and cellular signaling during epithelial-to-mesenchymal transition(EMT) of retinal pigment epithelial cells. METHODS: Retinal pigment epithelial(ARPE-19) cells were cultured with no serum for 12 h, and then with recombinant human TGF-β2 for different lengths of time. ARPE-19 cells were transfected with 1×106 TU/mL miR-let7 c mimcs(miR-let7 cM), miR-let7 c mimcs negative control(miR-let7cMNC) and miR-let7 c inhibitor(miR-let7 cI) using the transfection reagent. The expression of keratin-18, vimentin, N-cadherin, IKB alpha, p65 were detected by Western blot, quantitative polymerase chain reaction and immunofluorescence. RESULTS: The expression of miR-let7c was dramatically reduced and the nuclear factor-kappa B(NF-κB) signaling pathway was activated after induction by TGF-β2(P<0.05). In turn, overexpressed miR-let7 c significantly inhibited TGF-β2-induced EMT(P<0.05). However, miR-let7 c was unable to inhibit TGF-β2-induced EMT when the NF-κB signaling pathway was inhibited by BAY11-7082(P<0.01). CONCLUSION: The miR-let7 c regulates TGF-β2-induced EMT through the NF-κB signaling pathway in ARPE-19 cells.展开更多
AIM：To study the inhibition of nuclear factor kappa-B p65（NF-κB p65）antisense oligodeoxynucleotide（ASODN）on transdifferentiation of normal human lens epithelial cells induced by transforming growth factor-β2（T...AIM：To study the inhibition of nuclear factor kappa-B p65（NF-κB p65）antisense oligodeoxynucleotide（ASODN）on transdifferentiation of normal human lens epithelial cells induced by transforming growth factor-β2（TGF-β2）.·M ETHODS：NF-κBp65ASODNand NF-κBp65missense oligodeoxynucleotide（MSODN）were designed and synthesized.Human lens epithelial cell line（HLE B-3）cells were prepared for study and divided into 7 groups.Control group was HLE B-3 cells cultured in dulbecco’s modified eagle medium（DMEM）.T1,T2,and T3 group were HLE B-3 cells cultured in DMEM with 10 ng/m L TGF-β2 for 6h,12h,24h respectively.A＋T group was HLE B-3 cells cultured with 10 ng/m L TGF-β2for 24h after transfected by NF-κB p65 ASODN for 24h.M＋T group was HLE B-3 cells cultured with 10 ng/m L TGF-β2 for 24h after transfected by NF-κB p65 MSODN for 24h.The negative control group was HLE B-3 cells cultured with 10 ng/m L TGF-β2 for 24h after cultured with transfer agent（Hi Per Fect）for 24h.Cell morphology was observed at different time points using an inverted microscope.The expression of NF-κB p65 m RNA was detected with reverse transcription-polymerase chain reaction（RT-PCR）,and the expression ofα-smooth muscle actin（α-SMA）protein was assayed with ELISA.·RESULTS：With the TGF-β2 stimulation prolongation,the expression of NF-κB p65 m RNA and a-SMA protein increased in T1,T2,T3 groups compared with the control group,and the difference was statistically significant（〈0.05）.NF-κB p65 ASODN lowered the expression of NF-κB p65 m RNA andα-SMA protein induced by TGF-β2.NF-κB p65 MSODN and Hi Per Fect did not lower the expression of NF-κB p65 m RNA andα-SMA protein induced by TGF-β2.The difference between control group and A＋T group was not statistically significant（〉0.05）,but the difference among A＋T group and other groups was statistically significant（〈0.05）.·CONCLUSION：NF-κB p65 ASODN could lower the expression of NF-κB p65 m RNA andα-SMA protein induced by TGF-β2,and antagonized TGF-β2-induced transdifferentiation of HLE B-3.NF-κB p65ASODN could be used as a new biological therapeutic target of posterior capsular opacification.展开更多
AIM： To determine the temporal expression and pattern of Rel/nuclear factor （NF）-κB proteins in renal tissue in polycystic kidney disease （PKD）. METHODS： The renal expression of Rel/NF-κB proteins was determin...AIM： To determine the temporal expression and pattern of Rel/nuclear factor （NF）-κB proteins in renal tissue in polycystic kidney disease （PKD）. METHODS： The renal expression of Rel/NF-κB proteins was determined by immunohistochemistry, immunofuorescence and immunoblot analysis in Lewis polycystic kidney rats （LPK, a genetic ortholog of human nephronopthsis-9） from postnatal weeks 3 to 20. At each timepoint, renal disease progression and the mRNA expression of NF-κB-dependent genes （TNFa and CCL2） were determined. NF-κB was also histologically assessed in human PKD tissue.RESULTS： Progressive kidney enlargement in LPK rats was accompanied by increased renal cell proliferation and interstitial monocyte accumulation （peaking at weeks 3 and 10 respectively）, and progressive interstitial fibrosis （with a smooth muscle actin and Sirius Red deposition significantly increased compared to Lewis kidneys from weeks 3 to 6 onwards）. Rel/NF-κB proteins （phosphorylated-p105, p65, p50, c-Rel and RelB） were expressed in cystic epithelial cells （CECs） of LPK kidneys as early as postnatal week 3 and sustained until late-stage disease at week 20. From weeks 10 to 20, nuclear p65, p50, RelB and cytoplasmic IκBa protein levels, and TNFa and CCL2 expression, were upregulated in LPK compared to Lewis kidneys. NF-κB proteins were consistently expressed in CECs of human PKD. The DNA damage marker γ-H2AX was also identifed in the CECs of LPK and human polycystic kidneys. CONCLUSION： Several NF-κB proteins are consistently expressed in CECs in human and experimental PKD. These data suggest that the upregulation of both the canonical and non-canonical pathways of NF-κB signaling may be a constitutive and early pathological feature of cystic renal diseases.展开更多
AIM: To investigate the signaling mechanism of antioxidative action by curcumin and its impact on glucose disposal. METHODS: Male C57BL/6J mice were fed with either a normal diet (n = 10) or a high fat diet (HFD) (n =...AIM: To investigate the signaling mechanism of antioxidative action by curcumin and its impact on glucose disposal. METHODS: Male C57BL/6J mice were fed with either a normal diet (n = 10) or a high fat diet (HFD) (n = 20) to induce obesity and insulin resistance. After 16 wk, 10 HFD-fed mice were further treated with daily curcumin oral gavage at the dose of 50 mg/kg body weight (BW) (HFD + curcumin group). After 15 d of the curcumin supplementation, an intraperitoneal glucose tolerance test was performed. Fasting blood samples were also collected for insulin and glucose measurements. Insulin-sensitive tissues, including muscle, adipose tissue and the liver, were isolated for the assessments of malondialdehyde (MDA), reactive oxygen species (ROS)and nuclear factor erythroid-2-related factor-2 (Nrf2) signaling. RESULTS: We show here that in a HFD mouse model, short-term curcumin gavage attenuated glucose intolerance without affecting HFD-induced BW gain. Curcumin also attenuated HFD-induced elevations of MDA and ROS in the skeletal muscle, particularly in its mitochondrial fraction, but it had no such an effect in either adipose tissue or the liver of HFD-fed mice. Correspondingly, in skeletal muscle, the levels of total or nuclear content of Nrf2, as well as its downstream target, heme oxygenase-1, were reduced by HFD-feeding. Curcumin intervention dramatically reversed these defects in Nrf2 signaling. Further analysis of the relationship of oxidative stress with glucose level by a regression analysis showed a positive and significant correlation between the area under the curve of a glucose tolerance test with MDA levels either in muscle or muscular mitochondria. CONCLUSION: These findings suggest that the shortterm treatment of curcumin in HFD-fed mice effectively ameliorates muscular oxidative stress by activating Nrf2 function that is a novel mechanism for its effect in improving glucose intolerance.展开更多
Objective:To investigate the correlation between expressions of MMP-2 and NF-κB in the intracranial aneurysm wall,and explore their role in the mechanism of the occurrence,growth and rupture of intracranial aneurysms...Objective:To investigate the correlation between expressions of MMP-2 and NF-κB in the intracranial aneurysm wall,and explore their role in the mechanism of the occurrence,growth and rupture of intracranial aneurysms.Methods:RT-PCR was used to detect the expression of MMP-2 and NF-κB mRNA of 30 cases of intracranial aneurysm tissue and 10 cases of normal intracranial arterial tissue:Immunohistochemical method was used to detect the expression of MMP-2 and NF-κB protein.Results:the semi-quantitative analysis of MMP-2 and NF-κB in aneurysms tissues and normal tissues were statistically significant different from each other(P【0 05).Immunohistochemical staining results showed NF-κB was expressed in different layers.The expression of them were positive in intimal and medial,and the expression sites were located in the nucleus.MMP-2 were expressed in different layers of the aneurysm wall,and the expressions were positive in media and extima.The MMP-2 and NF-κB-positive expression of aneurysm wall were significantly higher than in normal cerebral arteries(P【0.05).MMP-2 and NF-κB mRNA expression showed positive correlation in the aneurysm wall tissue(r = 0.689,P = 0.005). Conclusions:The expressions of MMP-2 and NF-κB in the intracranial aneurysm wall tissue were significantly higher than in the normal intracranial arterial tissues.They have a synergistic effect on the formation of intracranial aneurysms.展开更多
OBJECTIVE The present study aimed to investigate the relationship between Wnt/β-catenin and Nrf2 signaling pathways,and understanding the mechanisms underlying the process of inflammatory in chronic obstructive pulmo...OBJECTIVE The present study aimed to investigate the relationship between Wnt/β-catenin and Nrf2 signaling pathways,and understanding the mechanisms underlying the process of inflammatory in chronic obstructive pulmonary disease(COPD),which was a serious disease of respiratory system.METHODS We duplicate the emphysema model with porcine pancreatic elastase(PPE)in Nrf2-/-and WT mouse for 21d,and intraperitoneal injection of Li Cl,the activator of Wnt/β-catenin signaling pathway from 14 d to the end.Hematoxylin and eosin(H&E)staining was performed to assess the histopathologic level,and immunohistochemistry(IHC)for Mac-3(the marker of macrophagocyte)and Ly6G(the marker of neutrophil)was used to observe the inflammatory infiltrate,while the levels of Wnt/β-catenin and Nrf2 signaling pathways related proteins heme oxygenase-1(HO-1),NAD(P)H:quinone oxidoreductase 1(NQO1),and the expression of inflammatory cytokine interleukin-6(IL-6)were detected by Western blotting of lung tissues.In vitro,cigarette smoke extract(CSE)-treated normal human bronchial epithelial(NHBE)cells,cell viability was examined by MTT assay,and then we treated recombinant human Wnt3a,si Nrf2 and si Wnt3a to measure the expression of Wnt3a,β-catenin,Nrf2,HO-1,NQO-1,and IL-6.Cellular immunofluorescence staining was employed to identify the nuclear translocation of Nrf2.RESULTS We found that the Li Cl-treated group has markedly decreased the damage of alveolar structure and inflammatory signs than the model group of WT mice rather than Nrf2-/-group.It also seen that Li Cl not only increasedβ-catenin,but it also led to a comparable increase in Nrf2,HO-1,NQO1,and decrease of IL-6 compared with WT model groups but except to Nrf2-/-group in vivo.And it showed that Wnt3atreatment has significantly increased the nuclear translocation of Nrf2 and the expression of HO-1 and NQO1,reduced the IL-6 release,while there has no significance when Nrf2 was blocked in CSE-induced NHBE cells.CONCLUSION Our results demonstrated that Wnt3a/β-catenin significantly balanced oxidative stress and attenuated inflammation reaction by promoting Nrf2 nuclear translocation and activity.展开更多
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 oligodeoxynucleo...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.展开更多
Objective： To investigate the β2-adrenoceptor （ β 2AR）-β-arrestin2-nuclear factor- K B （NF- κ B） signal transduction pathway and the intervention effects of oxymatrine in a rat model of ulcerative colitis. Me...Objective： To investigate the β2-adrenoceptor （ β 2AR）-β-arrestin2-nuclear factor- K B （NF- κ B） signal transduction pathway and the intervention effects of oxymatrine in a rat model of ulcerative colitis. Methods： Forty SD rats were randomly divided into four groups, which included the normal control group, the model group, the mesalazine group and the oxymatrine treatment group, with 10 rats per group. Experimental colitis induced with trinitrobenzene sulfonic acid （TNBS） was established in each group except the normal control group, The rats in the oxymatrine treatment group were treated with intramuscular injection of oxymatrine 63 mg/（kg.d） for 15 days and the rats in the mesalazine group were treated with mesalazine solution 0.5 g/（kg.d） by gastric lavage for 15 days. The rats in the normal control group and model group were treated with 3 mL water by gastric lavage for 15 days. Diarrhea and bloody stool were carefully observed. Histological changes in colonic tissue were examined on day 7 in 2 rats per group that were randomly selected. The expression of β 2AR, β -arrestin2 and NF- κ B p65 in colon tissue and spleen lymphocytes were detected with immunohistochemistry and Western immunoblotting techniques on day 16 after fasting for 24 h. Six rats died of lavage with 2 each in the normal control, the model group and the mesalazine group; and were not included in the analysis. Results： The rats in the model group suffered from looser stool and bloody purulent stool after modeling. But in the oxymatrine and mesalazine groups, looser stool and bloody purulent stool reduced after treatment. And the colonic wall in the model group was thickened and the colon length shortened. The colon mucosa was congested in multiple areas with edema, erosion, superficial or linear ulcer and scar formation, while the intestinal mucosa injury reduced in the mesalazine and oxymatrine groups （P〈0.01）. In colonic mucosa and in spleen lymphocytes, compared with the normal control group, the expression of NF- κ Bp65 were significantly increased （P〈0.01） in the model group while the expressions of β 2AR and β-arrestin2 were significantly decreased （P〈0.01）. Compared with the model group, the expression of NF- κ Bp65 was significantly decreased in the mesalazine group （P〈0.01） and oxymatrine treatment group （P〈0.01） while the expressions of β 2AR and β -arrestin2 were significantly increased （P〈0.01）. There were no statistically significant differences in the expression of β 2AR, β -arrestin2 and NF- κ Bp65 between the mesalazine group and oxymatrine group （P〉0.05）. Conclusions： The β 2AR- β -arrestin2-NF- κ B signal transduction pathway participated in the pathologic course of ulcerative colitis. Oxymatrine attenuated ulcerative colitis through regulating the β 2AR- β -arrestin2-NF- κB signal transduction pathway.展开更多
Background Tumor hypoxia, one of the features of solid tumors, is associated with chemo-resistance. Recently, nuclear factor-KB （NF-κB） was found to be activated during hypoxia. However, the impact of NF-κB activa...Background Tumor hypoxia, one of the features of solid tumors, is associated with chemo-resistance. Recently, nuclear factor-KB （NF-κB） was found to be activated during hypoxia. However, the impact of NF-κB activation on chemo-resistance during hypoxia remains unknown. Methods Human lung adenocarcinoma A549 cells were transfected with NF-κB p65siRNA and treated with cobalt chloride （COCI2） to mimic hypoxia in the presence or absence of cisplatin. NF-KB expression was measured by Western blotting, immune-fluorescence and real-time PCR. Hypoxia-inducible factor-1α （HIF-1α） and Bcl-2 expression were determined by Western blotting. Cell apoptosis and survival with half-maximum inhibitory concentration （IC50） of cisplatin were determined by Annexin V-FITC/PI and 3-（4, 5-dimethylthiazol-2-yl）-2, 5-diphenyltetrazolium bromide （MTT）, respectively. Results Exposure ofA549 cells to COCl2 increased nuclear HIF-1α protein expression, and enhanced NF-KB p65 protein nuclear accumulation （the mark of NF-κB activation） in a time and dose dependant manner. COCI2 did not promote apoptosis in A549 cells; on the contrary, it reduced cisplatin-induced apoptosis and increased the IC50 of cisplatin. However, when we inhibited CoCI2-induced activation of NF-κB through NF-κB p65siRNA, cisplatin-induced apoptosis was increased and IC50 of cisplatin was reduced to levels similar to those in control cells. Meanwhile, CoCI2-induced Bcl-2 over- expression was down-regulated in the presence of cisplatin when NF-κB activity was inhibited. Conclusion Up-regulating Bcl-2 might be involved in NF-κB activation induced resistance to cisplatin in A549 cells under CoCl2-induced chemical hypoxia.展开更多
Objective： To study the antitumor effects and associated mechanisms of extract of the Smilax china L. rhizome （SCR） on ovarian cancer cells. Methods： Ovarian cancer cells A2780 were treated with different concentr...Objective： To study the antitumor effects and associated mechanisms of extract of the Smilax china L. rhizome （SCR） on ovarian cancer cells. Methods： Ovarian cancer cells A2780 were treated with different concentrations of SCR extract （SCRE）, and compared with controls. Effects on cell growth were evaluated by cell counting kit-8 （CCK-8） assay; proliferation effects by EdU incorporation assay; cell cycle by propidium iodide staining; apoptosis by annexin V-fluorescein isothiocyanate/propidium iodide; cellular distribution of nuclear factor- κ B （NF-κ B） by immunofluorescence; protein levels of NF- κB, caspase-3, poly-adenosine diphosphate （ADP）-ribose polymerase （PARP）, Bcl-2-associated X protein （Bax）, cellular inhibitor of apoptosis （clAP）-1, anti-X-linked inhibitor of apoptosis protein （XlAP）, B-cell lymphoma-extra large （BcI-XL）, B-cell lymphoma-2 （Bcl-2） and AKT by Western blotting; and effects of SCRE combined with cisplatin or adriamycin on A2780 cells by CCK-8 assay. Results： SCRE suppressed A2780 cell proliferation in a dose-dependent manner （P〈0.05, /=〈0.01）, arrested cells in GJM phase and induced apoptosis by activating caspase-3, PARP and Bax. SCRE treatment also correlated with inhibition of NF-κ B and downregulation of Bcl-2, Bcl-XL, clAP-l, XlAP and AKT. SCRE can promote chemosensitivity to cisplatin and adriamycin in A2780 cells （P〈0.01）. Conclusion： SCR effectively inhibits NF- κ B, induces apoptosis and reduces chemoresistance to cisplatin and adriamycin in ovarian cancer cells, which might be its molecular basis for treating ovarian cancer.展开更多
Neuroinflammation has been recognized to play a critical role in the pathogenesis of Alzheimer＇s disease （AD）, which is pathologically characterized by the accumulation of senile plaques containing activated microg...Neuroinflammation has been recognized to play a critical role in the pathogenesis of Alzheimer＇s disease （AD）, which is pathologically characterized by the accumulation of senile plaques containing activated microglia and amyloid β-peptides （Aβ）. In the present study, we examined the neuroprotective effects of hydrogen sulfide （H2S） on neuroinflammation in rats with Aβ1-40 hippocampal injection. We found that Aβ-induced rats exhibited a disorder of pyramidal cell layer arrangement, and a decrease of mean pyramidal cell number in the CA1 hippocampal region compared with those in sham operated rats. NaHS （a donor of H2S, 5.6 mg/kg/d, i.p.） treatment for 3 weeks rescued neuronal cell death significantly. Moreover, we found that H2S dramatically suppressed the release of TNF-α, IL-1β and IL-6 in the hippocampus. Consistently, both immunohistochemistry and Western blotting assays showed that H2S inhibited the upregulation of COX-2 and the activation of NF-κB in the hippocampus. In conclusion, our data indicate that H2S suppresses neuroinflammation via inhibition of the NF-κB activation pathway in the Aβ-induced rat model and has potential value for AD therapy.展开更多
Osteoclast differentiation depends on receptor activator of nuclear factor-κB(RANK) signaling,which can be divided into triggering,amplifying and targeting phases based on how active the master regulator nuclear fact...Osteoclast differentiation depends on receptor activator of nuclear factor-κB(RANK) signaling,which can be divided into triggering,amplifying and targeting phases based on how active the master regulator nuclear factor of activated T-cells cytoplasmic 1(NFATc1) is. The triggering phase is characterized by immediateearly RANK signaling induced by RANK ligand(RANKL) stimulation mediated by three adaptor proteins,tumor necrosis factor receptor-associated factor 6,Grb-2-associated binder-2 and phospholipase C(PLC)γ2,leading to activation of IκB kinase,mitogen-activated protein kinases and the transcription factors nuclear factor(NF)-κB and activator protein-1(AP-1). Mice lacking NF-κB p50/p52 or the AP-1 subunit c-Fos(encoded by Fos) exhibit severe osteopetrosis due to a differentiation block in the osteoclast lineage. The amplification phase occurs about 24 h later in a RANKLinduced osteoclastogenic culture when Ca2+ oscillation starts and the transcription factor NFATc1 is abundantly produced. In addition to Ca2+ oscillation-dependent nuclear translocation and transcriptional auto-induction of NFATc1,a Ca2+ oscillation-independent,osteoblastdependent mechanism stabilizes NFATc1 protein in dif-ferentiating osteoclasts. Osteoclast precursors lacking PLCγ2,inositol-1,4,5-trisphosphate receptors,regulator of G-protein signaling 10,or NFATc1 show an impaired transition from the triggering to amplifying phases. The final targeting phase is mediated by activation of numerous NFATc1 target genes responsible for cell-cell fusion and regulation of bone-resorptive function. This review focuses on molecular mechanisms for each of the three phases of RANK signaling during osteoclast differentiation.展开更多
The Wnt/Frizzled signaling pathway participates in many inflammation-linked diseases. However, the inflammatory response mediated by the Wnt/Frizzled signaling pathway in experimental subarachnoid hemorrhage has not b...The Wnt/Frizzled signaling pathway participates in many inflammation-linked diseases. However, the inflammatory response mediated by the Wnt/Frizzled signaling pathway in experimental subarachnoid hemorrhage has not been thoroughly investigated. Consequently, in this study, we examined the potential role of the Wnt/Frizzled signaling pathway in early brain injury in rat models of subarachnoid hemorrhage.Simultaneously, possible neuroprotective mechanisms were also investigated. Experimental subarachnoid hemorrhage rat models were induced by injecting autologous blood into the prechiasmatic cistern. Experiment 1 was designed to examine expression of the Wnt/Frizzled signaling pathway in early brain injury induced by subarachnoid hemorrhage. In total, 42 adult rats were divided into sham(injection of equivalent volume of saline), 6-, 12-, 24-, 48-, 72-hour, and 1-week subarachnoid hemorrhage groups. Experiment 2 was designed to examine neuroprotective mechanisms of the Wnt/Frizzled signaling pathway in early brain injury induced by subarachnoid hemorrhage. Rats were treated with recombinant human Wnt1(rhwnt1), small interfering Wnt1(siwnt1) RNA, and monoclonal antibody of Frizzled1(anti-Frizzled1) at 48 hours after subarachnoid hemorrhage. Expression levels of Wnt1, Frizzled1, β-catenin, peroxisome proliferator-activated receptor-γ, CD36, and active nuclear factor-κB were examined by western blot assay and immunofluorescence staining. Microglia type conversion and inflammatory cytokine levels in brain tissue were examined by immunofluorescence staining and enzyme-linked immunosorbent assay. Our results show that compared with the sham group, expression levels of Wnt1, Frizzled1, and β-catenin were low and reduced to a minimum at 48 hours, gradually returning to baseline at 1 week after subarachnoid hemorrhage. rhwnt1 treatment markedly increased Wnt1 expression and alleviated subarachnoid hemorrhage-induced early brain injury(within 72 hours), including cortical cell apoptosis, brain edema, and neurobehavioral deficits, accompanied by increasing protein levels of β-catenin, CD36, and peroxisome proliferator-activated receptor-γ and decreasing protein levels of nuclear factor-κB. Of note, rhwnt1 promoted M2-type microglia conversion and inhibited release of inflammatory cytokines(interleukin-1β, interleukin-6, and tumor necrosis factor-α). In contrast, siwnt1 RNA and anti-Frizzled1 treatment both resulted in an opposite effect. In conclusion, the Wnt/Frizzled1 signaling pathway may participate in subarachnoid hemorrhage-induced early brain injury via inhibiting the inflammatory response, including regulating microglia type conversion and decreasing inflammatory cytokine release. The study was approved by the Animal Ethics Committee of Anhui Medical University and First Affiliated Hospital of USTC,Division of Life Sciences and Medicine, University of Science and Technology of China(approval No. LLSC-20180202) in May 2017.展开更多
基金This research was supported by the National 973 Program (2006 CB503901) the Major Project of Shanghai Science and Technology Development Foundation (02DJ14052-I)+1 种基金the Science and Technology Development Foundation of Shanghai Municipal Health Bureau (034043) the Young Doctor Training Project of Shanghai Municipal Health Bureau
文摘Objective To analyze the association of variants of hepatocyte nuclear factor-1α （HNF-1α） gene with type 2 diabetes in Chinese population. Methods In 152 unrelated type 2 diabetes patients and 93 unrelated controls, eleven single nucleotide polymorphisms （SNPs） were identified and genotyped. Statistical analyses were performed to investigate whether these SNPs were associated with diabetes status in our samples. Results In the individual SNP study, no SNP differed significantly in frequency between type 2 diabetes patients and controls. In the haplotype analysis, two haplotype blocks were identified. In haplotype block 1, no evidence was found between common HNF-1α haplotypes and type 2 diabetes. However, in haplotype block 2, a common haplotype GCGC formed by four tagging SNPs （tSNPs） was found to be associated with decreased risk of type 2 diabetes （odds ratio [OR] 0.6011, 95% confidence interval [CI] 0.4138-0.8732, P=0.0073, empirical P=0.0511, permutation test）. A similar trend was also observed in the diplotype analysis, indicating that the increasing copy number of the haplotype GCGC was associated with the decreased frequency of diabetes （P=0.0193）. Conclusion The results of this study provide evidence that the haplotype of HNF-1α decreases the risk of type 2 diabetes in Chinese individuals.
基金Supported by National Natural Science Foundation of China(No.81600754)。
文摘AIM: To explore the roles of microRNA-let7 c(miR-let7 c) and transforming growth factor-β2(TGF-β2) and cellular signaling during epithelial-to-mesenchymal transition(EMT) of retinal pigment epithelial cells. METHODS: Retinal pigment epithelial(ARPE-19) cells were cultured with no serum for 12 h, and then with recombinant human TGF-β2 for different lengths of time. ARPE-19 cells were transfected with 1×106 TU/mL miR-let7 c mimcs(miR-let7 cM), miR-let7 c mimcs negative control(miR-let7cMNC) and miR-let7 c inhibitor(miR-let7 cI) using the transfection reagent. The expression of keratin-18, vimentin, N-cadherin, IKB alpha, p65 were detected by Western blot, quantitative polymerase chain reaction and immunofluorescence. RESULTS: The expression of miR-let7c was dramatically reduced and the nuclear factor-kappa B(NF-κB) signaling pathway was activated after induction by TGF-β2(P<0.05). In turn, overexpressed miR-let7 c significantly inhibited TGF-β2-induced EMT(P<0.05). However, miR-let7 c was unable to inhibit TGF-β2-induced EMT when the NF-κB signaling pathway was inhibited by BAY11-7082(P<0.01). CONCLUSION: The miR-let7 c regulates TGF-β2-induced EMT through the NF-κB signaling pathway in ARPE-19 cells.
基金Supported by the Outstanding Young Medical Personnel of Qingdao City
文摘AIM：To study the inhibition of nuclear factor kappa-B p65（NF-κB p65）antisense oligodeoxynucleotide（ASODN）on transdifferentiation of normal human lens epithelial cells induced by transforming growth factor-β2（TGF-β2）.·M ETHODS：NF-κBp65ASODNand NF-κBp65missense oligodeoxynucleotide（MSODN）were designed and synthesized.Human lens epithelial cell line（HLE B-3）cells were prepared for study and divided into 7 groups.Control group was HLE B-3 cells cultured in dulbecco’s modified eagle medium（DMEM）.T1,T2,and T3 group were HLE B-3 cells cultured in DMEM with 10 ng/m L TGF-β2 for 6h,12h,24h respectively.A＋T group was HLE B-3 cells cultured with 10 ng/m L TGF-β2for 24h after transfected by NF-κB p65 ASODN for 24h.M＋T group was HLE B-3 cells cultured with 10 ng/m L TGF-β2 for 24h after transfected by NF-κB p65 MSODN for 24h.The negative control group was HLE B-3 cells cultured with 10 ng/m L TGF-β2 for 24h after cultured with transfer agent（Hi Per Fect）for 24h.Cell morphology was observed at different time points using an inverted microscope.The expression of NF-κB p65 m RNA was detected with reverse transcription-polymerase chain reaction（RT-PCR）,and the expression ofα-smooth muscle actin（α-SMA）protein was assayed with ELISA.·RESULTS：With the TGF-β2 stimulation prolongation,the expression of NF-κB p65 m RNA and a-SMA protein increased in T1,T2,T3 groups compared with the control group,and the difference was statistically significant（〈0.05）.NF-κB p65 ASODN lowered the expression of NF-κB p65 m RNA andα-SMA protein induced by TGF-β2.NF-κB p65 MSODN and Hi Per Fect did not lower the expression of NF-κB p65 m RNA andα-SMA protein induced by TGF-β2.The difference between control group and A＋T group was not statistically significant（〉0.05）,but the difference among A＋T group and other groups was statistically significant（〈0.05）.·CONCLUSION：NF-κB p65 ASODN could lower the expression of NF-κB p65 m RNA andα-SMA protein induced by TGF-β2,and antagonized TGF-β2-induced transdifferentiation of HLE B-3.NF-κB p65ASODN could be used as a new biological therapeutic target of posterior capsular opacification.
基金Supported by Funding from the National Health and Medical Research Council of Australia,Nos.457575 and 632647 to Rangan GKthe Baltimore Polycystic Kidney Disease Research and Clinical Core Center,No.P30DK090868+2 种基金DK095036 to Watnick Tsupported by an Australian Postgraduate Award(University of Sydney)the Michael Stern Polycystic Kidney Disease Research Fellowship
文摘AIM： To determine the temporal expression and pattern of Rel/nuclear factor （NF）-κB proteins in renal tissue in polycystic kidney disease （PKD）. METHODS： The renal expression of Rel/NF-κB proteins was determined by immunohistochemistry, immunofuorescence and immunoblot analysis in Lewis polycystic kidney rats （LPK, a genetic ortholog of human nephronopthsis-9） from postnatal weeks 3 to 20. At each timepoint, renal disease progression and the mRNA expression of NF-κB-dependent genes （TNFa and CCL2） were determined. NF-κB was also histologically assessed in human PKD tissue.RESULTS： Progressive kidney enlargement in LPK rats was accompanied by increased renal cell proliferation and interstitial monocyte accumulation （peaking at weeks 3 and 10 respectively）, and progressive interstitial fibrosis （with a smooth muscle actin and Sirius Red deposition significantly increased compared to Lewis kidneys from weeks 3 to 6 onwards）. Rel/NF-κB proteins （phosphorylated-p105, p65, p50, c-Rel and RelB） were expressed in cystic epithelial cells （CECs） of LPK kidneys as early as postnatal week 3 and sustained until late-stage disease at week 20. From weeks 10 to 20, nuclear p65, p50, RelB and cytoplasmic IκBa protein levels, and TNFa and CCL2 expression, were upregulated in LPK compared to Lewis kidneys. NF-κB proteins were consistently expressed in CECs of human PKD. The DNA damage marker γ-H2AX was also identifed in the CECs of LPK and human polycystic kidneys. CONCLUSION： Several NF-κB proteins are consistently expressed in CECs in human and experimental PKD. These data suggest that the upregulation of both the canonical and non-canonical pathways of NF-κB signaling may be a constitutive and early pathological feature of cystic renal diseases.
基金Supported by A National Natural Science Foundation of China Grant, No. 81072300 to Jin TR andYu ZW
文摘AIM: To investigate the signaling mechanism of antioxidative action by curcumin and its impact on glucose disposal. METHODS: Male C57BL/6J mice were fed with either a normal diet (n = 10) or a high fat diet (HFD) (n = 20) to induce obesity and insulin resistance. After 16 wk, 10 HFD-fed mice were further treated with daily curcumin oral gavage at the dose of 50 mg/kg body weight (BW) (HFD + curcumin group). After 15 d of the curcumin supplementation, an intraperitoneal glucose tolerance test was performed. Fasting blood samples were also collected for insulin and glucose measurements. Insulin-sensitive tissues, including muscle, adipose tissue and the liver, were isolated for the assessments of malondialdehyde (MDA), reactive oxygen species (ROS)and nuclear factor erythroid-2-related factor-2 (Nrf2) signaling. RESULTS: We show here that in a HFD mouse model, short-term curcumin gavage attenuated glucose intolerance without affecting HFD-induced BW gain. Curcumin also attenuated HFD-induced elevations of MDA and ROS in the skeletal muscle, particularly in its mitochondrial fraction, but it had no such an effect in either adipose tissue or the liver of HFD-fed mice. Correspondingly, in skeletal muscle, the levels of total or nuclear content of Nrf2, as well as its downstream target, heme oxygenase-1, were reduced by HFD-feeding. Curcumin intervention dramatically reversed these defects in Nrf2 signaling. Further analysis of the relationship of oxidative stress with glucose level by a regression analysis showed a positive and significant correlation between the area under the curve of a glucose tolerance test with MDA levels either in muscle or muscular mitochondria. CONCLUSION: These findings suggest that the shortterm treatment of curcumin in HFD-fed mice effectively ameliorates muscular oxidative stress by activating Nrf2 function that is a novel mechanism for its effect in improving glucose intolerance.
文摘Objective:To investigate the correlation between expressions of MMP-2 and NF-κB in the intracranial aneurysm wall,and explore their role in the mechanism of the occurrence,growth and rupture of intracranial aneurysms.Methods:RT-PCR was used to detect the expression of MMP-2 and NF-κB mRNA of 30 cases of intracranial aneurysm tissue and 10 cases of normal intracranial arterial tissue:Immunohistochemical method was used to detect the expression of MMP-2 and NF-κB protein.Results:the semi-quantitative analysis of MMP-2 and NF-κB in aneurysms tissues and normal tissues were statistically significant different from each other(P【0 05).Immunohistochemical staining results showed NF-κB was expressed in different layers.The expression of them were positive in intimal and medial,and the expression sites were located in the nucleus.MMP-2 were expressed in different layers of the aneurysm wall,and the expressions were positive in media and extima.The MMP-2 and NF-κB-positive expression of aneurysm wall were significantly higher than in normal cerebral arteries(P【0.05).MMP-2 and NF-κB mRNA expression showed positive correlation in the aneurysm wall tissue(r = 0.689,P = 0.005). Conclusions:The expressions of MMP-2 and NF-κB in the intracranial aneurysm wall tissue were significantly higher than in the normal intracranial arterial tissues.They have a synergistic effect on the formation of intracranial aneurysms.
基金The project supported by National Natural Science Foundation of China(81274172,81473267,30801535,81470003)
文摘OBJECTIVE The present study aimed to investigate the relationship between Wnt/β-catenin and Nrf2 signaling pathways,and understanding the mechanisms underlying the process of inflammatory in chronic obstructive pulmonary disease(COPD),which was a serious disease of respiratory system.METHODS We duplicate the emphysema model with porcine pancreatic elastase(PPE)in Nrf2-/-and WT mouse for 21d,and intraperitoneal injection of Li Cl,the activator of Wnt/β-catenin signaling pathway from 14 d to the end.Hematoxylin and eosin(H&E)staining was performed to assess the histopathologic level,and immunohistochemistry(IHC)for Mac-3(the marker of macrophagocyte)and Ly6G(the marker of neutrophil)was used to observe the inflammatory infiltrate,while the levels of Wnt/β-catenin and Nrf2 signaling pathways related proteins heme oxygenase-1(HO-1),NAD(P)H:quinone oxidoreductase 1(NQO1),and the expression of inflammatory cytokine interleukin-6(IL-6)were detected by Western blotting of lung tissues.In vitro,cigarette smoke extract(CSE)-treated normal human bronchial epithelial(NHBE)cells,cell viability was examined by MTT assay,and then we treated recombinant human Wnt3a,si Nrf2 and si Wnt3a to measure the expression of Wnt3a,β-catenin,Nrf2,HO-1,NQO-1,and IL-6.Cellular immunofluorescence staining was employed to identify the nuclear translocation of Nrf2.RESULTS We found that the Li Cl-treated group has markedly decreased the damage of alveolar structure and inflammatory signs than the model group of WT mice rather than Nrf2-/-group.It also seen that Li Cl not only increasedβ-catenin,but it also led to a comparable increase in Nrf2,HO-1,NQO1,and decrease of IL-6 compared with WT model groups but except to Nrf2-/-group in vivo.And it showed that Wnt3atreatment has significantly increased the nuclear translocation of Nrf2 and the expression of HO-1 and NQO1,reduced the IL-6 release,while there has no significance when Nrf2 was blocked in CSE-induced NHBE cells.CONCLUSION Our results demonstrated that Wnt3a/β-catenin significantly balanced oxidative stress and attenuated inflammation reaction by promoting Nrf2 nuclear translocation and activity.
文摘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.
基金Supported by the National Natural Science Foundation of China (No.30772878)
文摘Objective： To investigate the β2-adrenoceptor （ β 2AR）-β-arrestin2-nuclear factor- K B （NF- κ B） signal transduction pathway and the intervention effects of oxymatrine in a rat model of ulcerative colitis. Methods： Forty SD rats were randomly divided into four groups, which included the normal control group, the model group, the mesalazine group and the oxymatrine treatment group, with 10 rats per group. Experimental colitis induced with trinitrobenzene sulfonic acid （TNBS） was established in each group except the normal control group, The rats in the oxymatrine treatment group were treated with intramuscular injection of oxymatrine 63 mg/（kg.d） for 15 days and the rats in the mesalazine group were treated with mesalazine solution 0.5 g/（kg.d） by gastric lavage for 15 days. The rats in the normal control group and model group were treated with 3 mL water by gastric lavage for 15 days. Diarrhea and bloody stool were carefully observed. Histological changes in colonic tissue were examined on day 7 in 2 rats per group that were randomly selected. The expression of β 2AR, β -arrestin2 and NF- κ B p65 in colon tissue and spleen lymphocytes were detected with immunohistochemistry and Western immunoblotting techniques on day 16 after fasting for 24 h. Six rats died of lavage with 2 each in the normal control, the model group and the mesalazine group; and were not included in the analysis. Results： The rats in the model group suffered from looser stool and bloody purulent stool after modeling. But in the oxymatrine and mesalazine groups, looser stool and bloody purulent stool reduced after treatment. And the colonic wall in the model group was thickened and the colon length shortened. The colon mucosa was congested in multiple areas with edema, erosion, superficial or linear ulcer and scar formation, while the intestinal mucosa injury reduced in the mesalazine and oxymatrine groups （P〈0.01）. In colonic mucosa and in spleen lymphocytes, compared with the normal control group, the expression of NF- κ Bp65 were significantly increased （P〈0.01） in the model group while the expressions of β 2AR and β-arrestin2 were significantly decreased （P〈0.01）. Compared with the model group, the expression of NF- κ Bp65 was significantly decreased in the mesalazine group （P〈0.01） and oxymatrine treatment group （P〈0.01） while the expressions of β 2AR and β -arrestin2 were significantly increased （P〈0.01）. There were no statistically significant differences in the expression of β 2AR, β -arrestin2 and NF- κ Bp65 between the mesalazine group and oxymatrine group （P〉0.05）. Conclusions： The β 2AR- β -arrestin2-NF- κ B signal transduction pathway participated in the pathologic course of ulcerative colitis. Oxymatrine attenuated ulcerative colitis through regulating the β 2AR- β -arrestin2-NF- κB signal transduction pathway.
文摘Background Tumor hypoxia, one of the features of solid tumors, is associated with chemo-resistance. Recently, nuclear factor-KB （NF-κB） was found to be activated during hypoxia. However, the impact of NF-κB activation on chemo-resistance during hypoxia remains unknown. Methods Human lung adenocarcinoma A549 cells were transfected with NF-κB p65siRNA and treated with cobalt chloride （COCI2） to mimic hypoxia in the presence or absence of cisplatin. NF-KB expression was measured by Western blotting, immune-fluorescence and real-time PCR. Hypoxia-inducible factor-1α （HIF-1α） and Bcl-2 expression were determined by Western blotting. Cell apoptosis and survival with half-maximum inhibitory concentration （IC50） of cisplatin were determined by Annexin V-FITC/PI and 3-（4, 5-dimethylthiazol-2-yl）-2, 5-diphenyltetrazolium bromide （MTT）, respectively. Results Exposure ofA549 cells to COCl2 increased nuclear HIF-1α protein expression, and enhanced NF-KB p65 protein nuclear accumulation （the mark of NF-κB activation） in a time and dose dependant manner. COCI2 did not promote apoptosis in A549 cells; on the contrary, it reduced cisplatin-induced apoptosis and increased the IC50 of cisplatin. However, when we inhibited CoCI2-induced activation of NF-κB through NF-κB p65siRNA, cisplatin-induced apoptosis was increased and IC50 of cisplatin was reduced to levels similar to those in control cells. Meanwhile, CoCI2-induced Bcl-2 over- expression was down-regulated in the presence of cisplatin when NF-κB activity was inhibited. Conclusion Up-regulating Bcl-2 might be involved in NF-κB activation induced resistance to cisplatin in A549 cells under CoCl2-induced chemical hypoxia.
基金Partially supported by the Natural Science Foundation of Hubei Province(No.2013CFB389)the National Natural Science Foundation of China(No.81202962)
文摘Objective： To study the antitumor effects and associated mechanisms of extract of the Smilax china L. rhizome （SCR） on ovarian cancer cells. Methods： Ovarian cancer cells A2780 were treated with different concentrations of SCR extract （SCRE）, and compared with controls. Effects on cell growth were evaluated by cell counting kit-8 （CCK-8） assay; proliferation effects by EdU incorporation assay; cell cycle by propidium iodide staining; apoptosis by annexin V-fluorescein isothiocyanate/propidium iodide; cellular distribution of nuclear factor- κ B （NF-κ B） by immunofluorescence; protein levels of NF- κB, caspase-3, poly-adenosine diphosphate （ADP）-ribose polymerase （PARP）, Bcl-2-associated X protein （Bax）, cellular inhibitor of apoptosis （clAP）-1, anti-X-linked inhibitor of apoptosis protein （XlAP）, B-cell lymphoma-extra large （BcI-XL）, B-cell lymphoma-2 （Bcl-2） and AKT by Western blotting; and effects of SCRE combined with cisplatin or adriamycin on A2780 cells by CCK-8 assay. Results： SCRE suppressed A2780 cell proliferation in a dose-dependent manner （P〈0.05, /=〈0.01）, arrested cells in GJM phase and induced apoptosis by activating caspase-3, PARP and Bax. SCRE treatment also correlated with inhibition of NF-κ B and downregulation of Bcl-2, Bcl-XL, clAP-l, XlAP and AKT. SCRE can promote chemosensitivity to cisplatin and adriamycin in A2780 cells （P〈0.01）. Conclusion： SCR effectively inhibits NF- κ B, induces apoptosis and reduces chemoresistance to cisplatin and adriamycin in ovarian cancer cells, which might be its molecular basis for treating ovarian cancer.
基金supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions(No.Jx10131801095 to HongZhou)
文摘Neuroinflammation has been recognized to play a critical role in the pathogenesis of Alzheimer＇s disease （AD）, which is pathologically characterized by the accumulation of senile plaques containing activated microglia and amyloid β-peptides （Aβ）. In the present study, we examined the neuroprotective effects of hydrogen sulfide （H2S） on neuroinflammation in rats with Aβ1-40 hippocampal injection. We found that Aβ-induced rats exhibited a disorder of pyramidal cell layer arrangement, and a decrease of mean pyramidal cell number in the CA1 hippocampal region compared with those in sham operated rats. NaHS （a donor of H2S, 5.6 mg/kg/d, i.p.） treatment for 3 weeks rescued neuronal cell death significantly. Moreover, we found that H2S dramatically suppressed the release of TNF-α, IL-1β and IL-6 in the hippocampus. Consistently, both immunohistochemistry and Western blotting assays showed that H2S inhibited the upregulation of COX-2 and the activation of NF-κB in the hippocampus. In conclusion, our data indicate that H2S suppresses neuroinflammation via inhibition of the NF-κB activation pathway in the Aβ-induced rat model and has potential value for AD therapy.
基金Supported by Grants from MEXT Japan,No.23790265(to Kuroda Y)and No.21390425(to Matsuo K)
文摘Osteoclast differentiation depends on receptor activator of nuclear factor-κB(RANK) signaling,which can be divided into triggering,amplifying and targeting phases based on how active the master regulator nuclear factor of activated T-cells cytoplasmic 1(NFATc1) is. The triggering phase is characterized by immediateearly RANK signaling induced by RANK ligand(RANKL) stimulation mediated by three adaptor proteins,tumor necrosis factor receptor-associated factor 6,Grb-2-associated binder-2 and phospholipase C(PLC)γ2,leading to activation of IκB kinase,mitogen-activated protein kinases and the transcription factors nuclear factor(NF)-κB and activator protein-1(AP-1). Mice lacking NF-κB p50/p52 or the AP-1 subunit c-Fos(encoded by Fos) exhibit severe osteopetrosis due to a differentiation block in the osteoclast lineage. The amplification phase occurs about 24 h later in a RANKLinduced osteoclastogenic culture when Ca2+ oscillation starts and the transcription factor NFATc1 is abundantly produced. In addition to Ca2+ oscillation-dependent nuclear translocation and transcriptional auto-induction of NFATc1,a Ca2+ oscillation-independent,osteoblastdependent mechanism stabilizes NFATc1 protein in dif-ferentiating osteoclasts. Osteoclast precursors lacking PLCγ2,inositol-1,4,5-trisphosphate receptors,regulator of G-protein signaling 10,or NFATc1 show an impaired transition from the triggering to amplifying phases. The final targeting phase is mediated by activation of numerous NFATc1 target genes responsible for cell-cell fusion and regulation of bone-resorptive function. This review focuses on molecular mechanisms for each of the three phases of RANK signaling during osteoclast differentiation.
基金supported by the Natural Science Foundation of Anhui Province of China,No.1508085QH184(to YW)
文摘The Wnt/Frizzled signaling pathway participates in many inflammation-linked diseases. However, the inflammatory response mediated by the Wnt/Frizzled signaling pathway in experimental subarachnoid hemorrhage has not been thoroughly investigated. Consequently, in this study, we examined the potential role of the Wnt/Frizzled signaling pathway in early brain injury in rat models of subarachnoid hemorrhage.Simultaneously, possible neuroprotective mechanisms were also investigated. Experimental subarachnoid hemorrhage rat models were induced by injecting autologous blood into the prechiasmatic cistern. Experiment 1 was designed to examine expression of the Wnt/Frizzled signaling pathway in early brain injury induced by subarachnoid hemorrhage. In total, 42 adult rats were divided into sham(injection of equivalent volume of saline), 6-, 12-, 24-, 48-, 72-hour, and 1-week subarachnoid hemorrhage groups. Experiment 2 was designed to examine neuroprotective mechanisms of the Wnt/Frizzled signaling pathway in early brain injury induced by subarachnoid hemorrhage. Rats were treated with recombinant human Wnt1(rhwnt1), small interfering Wnt1(siwnt1) RNA, and monoclonal antibody of Frizzled1(anti-Frizzled1) at 48 hours after subarachnoid hemorrhage. Expression levels of Wnt1, Frizzled1, β-catenin, peroxisome proliferator-activated receptor-γ, CD36, and active nuclear factor-κB were examined by western blot assay and immunofluorescence staining. Microglia type conversion and inflammatory cytokine levels in brain tissue were examined by immunofluorescence staining and enzyme-linked immunosorbent assay. Our results show that compared with the sham group, expression levels of Wnt1, Frizzled1, and β-catenin were low and reduced to a minimum at 48 hours, gradually returning to baseline at 1 week after subarachnoid hemorrhage. rhwnt1 treatment markedly increased Wnt1 expression and alleviated subarachnoid hemorrhage-induced early brain injury(within 72 hours), including cortical cell apoptosis, brain edema, and neurobehavioral deficits, accompanied by increasing protein levels of β-catenin, CD36, and peroxisome proliferator-activated receptor-γ and decreasing protein levels of nuclear factor-κB. Of note, rhwnt1 promoted M2-type microglia conversion and inhibited release of inflammatory cytokines(interleukin-1β, interleukin-6, and tumor necrosis factor-α). In contrast, siwnt1 RNA and anti-Frizzled1 treatment both resulted in an opposite effect. In conclusion, the Wnt/Frizzled1 signaling pathway may participate in subarachnoid hemorrhage-induced early brain injury via inhibiting the inflammatory response, including regulating microglia type conversion and decreasing inflammatory cytokine release. The study was approved by the Animal Ethics Committee of Anhui Medical University and First Affiliated Hospital of USTC,Division of Life Sciences and Medicine, University of Science and Technology of China(approval No. LLSC-20180202) in May 2017.
