Objective:To discuss the effect of insulin and metformin on amethylation and glycolipid metabolism of peroxisome proliferator-activated receptor γ coactivator-1A(PPARGC1A) of rat offspring with gestational diabetes m...Objective:To discuss the effect of insulin and metformin on amethylation and glycolipid metabolism of peroxisome proliferator-activated receptor γ coactivator-1A(PPARGC1A) of rat offspring with gestational diabetes mellitus(GDM).Methods:A total of 45 pregnant rats received the intraperitoneal injection of streptozotocin to establish the pregnant rat model of GDM.A total of 21 pregnant rats with GDM were randomly divided into three groups,with 7ruts in each group,namely the insulin group,metformin group and control group.Rats in the insulin group received the abdominal subcutaneous injection of 1 mL/kg recombinant insulin glargine at 18:00 every day.Rats in the metformin group received the intragastric infusion of metformin hydrochloride at 18:00 every day,with the first dose of 300 mg/kg.The doses of two groups were adjusted every 3 d to maintain the blood glucose level at 2.65-7.62 mmol/L.Rats in the control group received the intragastric infusion of 1 mL normal saline at 18:00 every day.After the natural delivery of pregnant rats.10 offspring rats were randomly selected from each group.At birth,4 wk and 8 wk after the birth of offspring rats,the weight of offspring rats was measured.The blood glucose level of offspring rats was measured at 4wk and 8 wk,while the level of serum insulin,triglyceride and leptin was measured at 8 wk.Results:The weight of offspring rats at birth in the insulin group and metformin group was significantly lower than the one in the control group(P<0.05),and there was no significant difference at 4 wk and 8 wk among three groups(P>0.05).The fasting blood glucose and random blood glucose in the insulin group and metformin group at 4 wk and 8 wk were all significantly lower than ones in the control group(P<0.05);there was no significant difference between the insulin group and metformin group(P>0.05).The expression of PPARGC1 A mRNA in the insulin group and metformin group was significantly higher and the methylation level of PPARGC1 A was significantly lower than the one in the control group(P<0.05),but there was no significant difference between the insulin group and metformin group(P>0.05).Insulin and leptin at 8 wk in the insulin group and metformin group were significantly higher,while triglyceride was significantly lower than the one in the control group(P<0.05);triglyceride level of rats in the insulin group was significantly higher than the one in the metformin group(P<0.05).There was no significant difference in insulin and leptin level of offspring rats between the insulin group and metformin group(P>0.05).Conclusions:GDM can induce the methylation of PPARGC1 A of offspring rats to reduce the expression of PPARGC1 A mRNA and then cause the disorder of glycolipid metabolism when the offspring rats grow up;the insulin or metformin in the treatment of pregnant rats with GDM can reduce the methylation level of PPARGC1 A and thus improve the abnormal glycolipid metabolism of offspring rats.展开更多
Activated G-protein-coupled receptor 39(GPR39)has been shown to attenuate inflammation by interacting with sirtuin 1(SIRT1)and peroxisome proliferator-activated receptor-γcoactivator 1α(PGC-1α).However,whether GPR3...Activated G-protein-coupled receptor 39(GPR39)has been shown to attenuate inflammation by interacting with sirtuin 1(SIRT1)and peroxisome proliferator-activated receptor-γcoactivator 1α(PGC-1α).However,whether GPR39 attenuates neuropathic pain remains unclear.In this study,we established a Sprague-Dawley rat model of spared nerve injury-induced neuropathic pain and found that GPR39 expression was significantly decreased in neurons and microglia in the spinal dorsal horn compared with sham-operated rats.Intrathecal injection of TC-G 1008,a specific agonist of GPR39,significantly alleviated mechanical allodynia in the rats with spared nerve injury,improved spinal cord mitochondrial biogenesis,and alleviated neuroinflammation.These changes were abolished by GPR39 small interfering RNA(siRNA),Ex-527(SIRT1 inhibitor),and PGC-1αsiRNA.Taken together,these findings show that GPR39 activation ameliorates mechanical allodynia by activating the SIRT1/PGC-1αpathway in rats with spared nerve injury.展开更多
The biological effects of thyroid hormone (T3) are mediated by the thyroid hormone receptor (TR). Amphibian metamorphosis is one of the most dramatic processes that are dependent on T3. T3 regulates a series of orches...The biological effects of thyroid hormone (T3) are mediated by the thyroid hormone receptor (TR). Amphibian metamorphosis is one of the most dramatic processes that are dependent on T3. T3 regulates a series of orchestrated developmental changes, which ultimately result in the conversion of an aquatic herbivorous tadpole to a terrestrial carnivorous frog. T3 is presumed to bind to TRs, which in turn recruit coactivators, leading to gene activation. The best-studied coactivators belong to the p160 or SRC family. Members of this family include SRC1/NCoA-1, SRC2/TIF2/GRIP1, and SRC3/pCIP/ACTR/AIB-1/RAC-3/TRAM-1. These SRCs interact directly with liganded TR and function as adapter molecules to recruit other coactivators such as p300/CBP. Here, we studied the expression patterns of these coactivators during various stages of development. Amongst the coactivators cloned in Xenopus laevis, SRC3 was found to be dramatically upregulated during natural and T3-induced metamorphosis, and SRC2 and p300 are expressed throughout postembryonic development with little change in their expression levels. These results support the view that these coactivators participate in gene regulation by TR during metamorphosis.展开更多
Since we had previously demonstrated that siRNAs to tristetraprolin (TTP) markedly inhibited insulin stimulation of hepatic HMG-CoA reductase (HMGR) transcription, we investigated the effects of transfecting rat liver...Since we had previously demonstrated that siRNAs to tristetraprolin (TTP) markedly inhibited insulin stimulation of hepatic HMG-CoA reductase (HMGR) transcription, we investigated the effects of transfecting rat liver with TTP constructs. We found that transfecting diabetic rats with TTP did not increase HMGR transcription but rather led to modest inhibition. We then investigated whether co-transfection with protein kinase B, hepatic form (AKT2), might lead to phosphorylation and result in activation of HMGR transcription. We found that this treatment resulted in near complete inhibition of transcription. Transfection with peroxisome proliferator-activated receptor g coactivator (PGC-1a) also inhibited HMGR transcription. These results show that although TTP is needed for activation of HMGR transcription, it cannot by itself activate this process. AKT2 and PGC-1a, which mediate the activation of gluconeogenic genes by insulin, exert the opposite effect on HMGR.展开更多
Death following situations of intense emotional stress has been linked to the cardiac pathology described as stress cardiomyopathy, whose pathomechanism is still not clear. In this study, we sought to determine, via a...Death following situations of intense emotional stress has been linked to the cardiac pathology described as stress cardiomyopathy, whose pathomechanism is still not clear. In this study, we sought to determine, via an animal model, whether the transcriptional coactivator peroxisome proliferator-activated receptor γ coactivator-1alpha (PGC-1α) and the amino peptide neuropeptide Y (NPY) play a role in the pathogenesis of this cardiac entity. Male Sprague-Dawley rats in the experimental group were subjected to immobilization in a plexy glass box for 1 h, which was followed by low voltage elec-tric foot shock for about 1h at 10s intervals in a cage fitted with metallic rods. After 25 days the rats were sacrificed and sections of their hearts were processed. Hematoxylin-eosin staining of cardiac tissues revealed the characteristic cardiac lesions of stress cardiomyopathy such as contraction band necrosis, inflammatory cell infiltration and fibrosis. The semi-quantitative RT-PCR analysis for PGC-1α mRNA expression showed significant overexpression of PGC1-α in the stress-subjected rats (P<0.05). Fluorescence immunohistochemistry revealed a higher production of NPY in the stress-subjected rats as compared to the control rats (P=0.0027). Thus, we are led to conclude that following periods of intense stress, an increased expression of PGC1-α in the heart and an overflow of NPY may lead to stress car-diomyopathy and even death in susceptible victims. Moreover, these markers can be used to identify stress cardiomyopathy as the cause of sudden death in specific cases.展开更多
OBJECTIVE:To explore the effect of acupuncture treatment on cerebral ischaemia-reperfusion injury(CIRI)and reveal the underlying mechanism of the effect based on nuclear receptor coactivator 4(NCOA4)mediated ferritino...OBJECTIVE:To explore the effect of acupuncture treatment on cerebral ischaemia-reperfusion injury(CIRI)and reveal the underlying mechanism of the effect based on nuclear receptor coactivator 4(NCOA4)mediated ferritinophagy.METHODS:Sprague-Dawley male rats were divided into four groups:the sham group,model group,acupuncture group,and sham acupuncture group.After 2 h of middle cerebral artery occlusion(MCAO),reperfusion was performed for 24 h to induce CIRI.The rats were treated with acupuncture at the Neiguan(PC6)and Shuigou(GV26)acupoints.Their neurological function was evaluated by taking their Bederson scores at 2 h after ischaemia and 24 h after reperfusion.Triphenyltetrazolium chloride staining was applied to assess the cerebral infarct volume at 24 h after reperfusion.The malondialdehyde(MDA)and ferrous iron(Fe^(2+))levels were observed after 24 h of reperfusion using an assay kit.Western blotting was performed to detect the expression of NCOA4 and ferritin heavy chain 1(FTH1)at 24 h after reperfusion.Moreover,the colocalization of ferritin with neurons,NCOA4 with microtubule-associated protein 1 light chain 3(LC3),and NCOA4 with ferritin was visualized using immunofluorescence staining.RESULTS:Acupuncture significantly improved neurological function and decreased cerebral infarct volume in the acupuncture group.Following CIRI,the expression of NCOA4,LC3 and FTH1 was increased,which enhanced ferritinophagy and induced an inappropriate accumulation of Fe^(2+)and MDA in the ischaemic brain.However,acupuncture dramatically downregulated the expression of NCOA4,LC3 and FTH1,inhibited the overactivation of ferritinophagy,and decreased the levels of MDA and Fe^(2+).CONCLUSIONS:Acupuncture can inhibit NCOA4-mediated ferritinophagy and protect neurons against CIRI in a rat model.展开更多
Transcriptional coactivators regulate the rate of gene expression in the nucleus.Nuclear receptor coactivator 6(NCOA6),a coactivator,has been implicated in embryonic development,metabolism,and cancer pathogenesis,but ...Transcriptional coactivators regulate the rate of gene expression in the nucleus.Nuclear receptor coactivator 6(NCOA6),a coactivator,has been implicated in embryonic development,metabolism,and cancer pathogenesis,but its role in innate immunity and inflammatory diseases remains unclear.Here,we demonstrated that NCOA6 was expressed in monocytes and macrophages and that its level was increased under proinflammatory conditions.Unexpectedly,nuclear NCOA6 was found to translocate to the cytoplasm in activated monocytes and then become incorporated into the inflammasome with NLRP3 and ASC,forming cytoplasmic specks.Mechanistically,NCOA6 associated with the ATP hydrolysis motifs in the NACHT domain of NLRP3,promoting the oligomerization of NLRP3 and ASC and thereby instigating the production of IL-1βand active caspase-1.Of note,Ncoa6 deficiency markedly inhibited NLRP3 hyperactivation caused by the Nlrp3^(R258W) gain-of-function mutation in macrophages.Genetic ablation of Ncoa6 substantially attenuated the severity of two NLRP3-dependent diseases,folic-induced acute tubular necrosis and crystal-induced arthritis,in mice.Consistent with these findings,NCOA6 was highly expressed in macrophages derived from gout patients,and NCOA6-positive macrophages were significantly enriched in gout macrophages according to the transcriptome profiling results.Conclusively,NCOA6 is a critical regulator of NLRP3 inflammasome activation and is therefore a promising target for NLRP3-dependent diseases,including gout.展开更多
Objective: To explore the relationship between peroxisome proliferator activated receptor-gamma (PPARγ) and peroxisome proliferator-activated receptor-gamma coactivator-1 (PGC-1) expression in gastric carcinoma ...Objective: To explore the relationship between peroxisome proliferator activated receptor-gamma (PPARγ) and peroxisome proliferator-activated receptor-gamma coactivator-1 (PGC-1) expression in gastric carcinoma (GC), and analyze their correlations with clinicopathological features and clinical outcomes of patients. Methods:The two-step immunohistochemical method was used to detect the expression of PPARγ and PGC-1 in 179 cases of GC, and 108 cases of matched normal gastric mucosa. Besides, 16 cases of fresh GC specimens and corresponding normal gastric mucosa were detected for PGC-1 expression with Western blotting. Results: The positive rates of PPART and PGC-1 expression were significantly lower in GC (54.75%, 49.16%) than in normal gastric mucosa (70.37%, 71.30%), respectively (P〈0.05). The decreased expression of PGC-1 in GC was confirmed ha our Western blot analysis (P=0.004). PPAR7 and PGC-1 expressions were related to Lauren's types ofGC (P〈0.05). Positive correlation was found between PPART and PGC-1 expression in GC (rk=0.422, P〈0.001). The survival time of PPART negative and positive patients was 36.6±3.0 vs. 38.5_+2.7 months, and no statistical difference was found between the 5-year survival rates of two groups (34.4% vs. 44.1%, P=0.522, log-rank test); the survival time of PGC-1 negative and positive patients was 36.2±2.8 vs. 39.9±2.9 months, while no statistical difference was found between the 5-year survival rates of the two groups (32.0% vs. 48.2%, P=0.462, log-rank test) Conclusions'. Decreased expression of PPARγand PGC-1 in GC was related to the Lauren's classification. Their expressions in GC were positively correlated, indicating that their fimctions in gastric carcinogenesis may be closely related.展开更多
In mammals,the timing of physiological,biochemical and behavioral processes over a 24-h period is controlled by circadian rhythms.To entrain the master clock located in the suprachiasmatic nucleus of the hypothalamus ...In mammals,the timing of physiological,biochemical and behavioral processes over a 24-h period is controlled by circadian rhythms.To entrain the master clock located in the suprachiasmatic nucleus of the hypothalamus to a precise 24-h rhythm,environmental zeitgebers are used by the circadian system.This is done primarily by signals from the retina via the retinohypothalamic tract,but other cues like exercise,feeding,temperature,anxiety,and social events have also been shown to act as non-photic zeitgebers.The recently identified myokine irisin is proposed to serve as an entraining non-photic signal of exercise.Irisin is a product of cleavage and modification from its precursor membrane fibronectin typeⅢdomain-containing protein 5(FNDC5)in response to exercise.Apart from well-known peripheral effects,such as inducing the"browning"of white adipocytes,irisin can penetrate the blood-brain barrier and display the effects on the brain.Experimental data suggest that FNDC5/irisin mediates the positive effects of physical activity on brain functions.In several brain areas,irisin induces the production of brain-derived neurotrophic factor(BDNF).In the master clock,a significant role in gating photic stimuli in the retinohypothalamic synapse for BDNF is suggested.However,the brain receptor for irisin remains unknown.In the current review,the interactions of physical activity and the irisin/BDNF axis with the circadian system are reconceptualized.展开更多
基金supported by Shandong Natural Science Fund(Y2008c170)
文摘Objective:To discuss the effect of insulin and metformin on amethylation and glycolipid metabolism of peroxisome proliferator-activated receptor γ coactivator-1A(PPARGC1A) of rat offspring with gestational diabetes mellitus(GDM).Methods:A total of 45 pregnant rats received the intraperitoneal injection of streptozotocin to establish the pregnant rat model of GDM.A total of 21 pregnant rats with GDM were randomly divided into three groups,with 7ruts in each group,namely the insulin group,metformin group and control group.Rats in the insulin group received the abdominal subcutaneous injection of 1 mL/kg recombinant insulin glargine at 18:00 every day.Rats in the metformin group received the intragastric infusion of metformin hydrochloride at 18:00 every day,with the first dose of 300 mg/kg.The doses of two groups were adjusted every 3 d to maintain the blood glucose level at 2.65-7.62 mmol/L.Rats in the control group received the intragastric infusion of 1 mL normal saline at 18:00 every day.After the natural delivery of pregnant rats.10 offspring rats were randomly selected from each group.At birth,4 wk and 8 wk after the birth of offspring rats,the weight of offspring rats was measured.The blood glucose level of offspring rats was measured at 4wk and 8 wk,while the level of serum insulin,triglyceride and leptin was measured at 8 wk.Results:The weight of offspring rats at birth in the insulin group and metformin group was significantly lower than the one in the control group(P<0.05),and there was no significant difference at 4 wk and 8 wk among three groups(P>0.05).The fasting blood glucose and random blood glucose in the insulin group and metformin group at 4 wk and 8 wk were all significantly lower than ones in the control group(P<0.05);there was no significant difference between the insulin group and metformin group(P>0.05).The expression of PPARGC1 A mRNA in the insulin group and metformin group was significantly higher and the methylation level of PPARGC1 A was significantly lower than the one in the control group(P<0.05),but there was no significant difference between the insulin group and metformin group(P>0.05).Insulin and leptin at 8 wk in the insulin group and metformin group were significantly higher,while triglyceride was significantly lower than the one in the control group(P<0.05);triglyceride level of rats in the insulin group was significantly higher than the one in the metformin group(P<0.05).There was no significant difference in insulin and leptin level of offspring rats between the insulin group and metformin group(P>0.05).Conclusions:GDM can induce the methylation of PPARGC1 A of offspring rats to reduce the expression of PPARGC1 A mRNA and then cause the disorder of glycolipid metabolism when the offspring rats grow up;the insulin or metformin in the treatment of pregnant rats with GDM can reduce the methylation level of PPARGC1 A and thus improve the abnormal glycolipid metabolism of offspring rats.
基金supported by the National Notural Science Foundation of China,Nos.82071556 and 82271291 (both to WM)
文摘Activated G-protein-coupled receptor 39(GPR39)has been shown to attenuate inflammation by interacting with sirtuin 1(SIRT1)and peroxisome proliferator-activated receptor-γcoactivator 1α(PGC-1α).However,whether GPR39 attenuates neuropathic pain remains unclear.In this study,we established a Sprague-Dawley rat model of spared nerve injury-induced neuropathic pain and found that GPR39 expression was significantly decreased in neurons and microglia in the spinal dorsal horn compared with sham-operated rats.Intrathecal injection of TC-G 1008,a specific agonist of GPR39,significantly alleviated mechanical allodynia in the rats with spared nerve injury,improved spinal cord mitochondrial biogenesis,and alleviated neuroinflammation.These changes were abolished by GPR39 small interfering RNA(siRNA),Ex-527(SIRT1 inhibitor),and PGC-1αsiRNA.Taken together,these findings show that GPR39 activation ameliorates mechanical allodynia by activating the SIRT1/PGC-1αpathway in rats with spared nerve injury.
文摘The biological effects of thyroid hormone (T3) are mediated by the thyroid hormone receptor (TR). Amphibian metamorphosis is one of the most dramatic processes that are dependent on T3. T3 regulates a series of orchestrated developmental changes, which ultimately result in the conversion of an aquatic herbivorous tadpole to a terrestrial carnivorous frog. T3 is presumed to bind to TRs, which in turn recruit coactivators, leading to gene activation. The best-studied coactivators belong to the p160 or SRC family. Members of this family include SRC1/NCoA-1, SRC2/TIF2/GRIP1, and SRC3/pCIP/ACTR/AIB-1/RAC-3/TRAM-1. These SRCs interact directly with liganded TR and function as adapter molecules to recruit other coactivators such as p300/CBP. Here, we studied the expression patterns of these coactivators during various stages of development. Amongst the coactivators cloned in Xenopus laevis, SRC3 was found to be dramatically upregulated during natural and T3-induced metamorphosis, and SRC2 and p300 are expressed throughout postembryonic development with little change in their expression levels. These results support the view that these coactivators participate in gene regulation by TR during metamorphosis.
文摘Since we had previously demonstrated that siRNAs to tristetraprolin (TTP) markedly inhibited insulin stimulation of hepatic HMG-CoA reductase (HMGR) transcription, we investigated the effects of transfecting rat liver with TTP constructs. We found that transfecting diabetic rats with TTP did not increase HMGR transcription but rather led to modest inhibition. We then investigated whether co-transfection with protein kinase B, hepatic form (AKT2), might lead to phosphorylation and result in activation of HMGR transcription. We found that this treatment resulted in near complete inhibition of transcription. Transfection with peroxisome proliferator-activated receptor g coactivator (PGC-1a) also inhibited HMGR transcription. These results show that although TTP is needed for activation of HMGR transcription, it cannot by itself activate this process. AKT2 and PGC-1a, which mediate the activation of gluconeogenic genes by insulin, exert the opposite effect on HMGR.
基金supported by a grant from the National Natural Science Foundation of China(No.81172898)
文摘Death following situations of intense emotional stress has been linked to the cardiac pathology described as stress cardiomyopathy, whose pathomechanism is still not clear. In this study, we sought to determine, via an animal model, whether the transcriptional coactivator peroxisome proliferator-activated receptor γ coactivator-1alpha (PGC-1α) and the amino peptide neuropeptide Y (NPY) play a role in the pathogenesis of this cardiac entity. Male Sprague-Dawley rats in the experimental group were subjected to immobilization in a plexy glass box for 1 h, which was followed by low voltage elec-tric foot shock for about 1h at 10s intervals in a cage fitted with metallic rods. After 25 days the rats were sacrificed and sections of their hearts were processed. Hematoxylin-eosin staining of cardiac tissues revealed the characteristic cardiac lesions of stress cardiomyopathy such as contraction band necrosis, inflammatory cell infiltration and fibrosis. The semi-quantitative RT-PCR analysis for PGC-1α mRNA expression showed significant overexpression of PGC1-α in the stress-subjected rats (P<0.05). Fluorescence immunohistochemistry revealed a higher production of NPY in the stress-subjected rats as compared to the control rats (P=0.0027). Thus, we are led to conclude that following periods of intense stress, an increased expression of PGC1-α in the heart and an overflow of NPY may lead to stress car-diomyopathy and even death in susceptible victims. Moreover, these markers can be used to identify stress cardiomyopathy as the cause of sudden death in specific cases.
基金the National Natural Science Foundation of China:Mechanism of Acupuncture in Extending Thrombolytic Time Window of Cerebral Infarction Based on Nuclear Receptor Coactivator 4 Mediated Ferritinophagy(No.82205238)National Natural Science Foundation of China:Exploring the Mechanism of Acupuncture Improving Thrombolytic Safety in Cerebral Infarction through the ERK1/2-mTOR Pathway Based on Autophagy Apoptosis Interaction(No.82074525)+1 种基金Natural Science Foundation of Jiangsu Province:Experimental Study on Acupuncture Regulation of Ferroptosis-NLRP3 Inflammasome Pathway to Reduce Hemorrhagic Transformation after Thrombolysis in Cerebral Infarction(No.BK20210689)Traditional Chinese Medicine Science and Technology Development Plan Project of Jiangsu Province:Clinical and Experimental Study on Acupuncture Improving the Safety of rt-PA Intravenous Thrombolysis in Cerebral Infarction(No.YB2020005)。
文摘OBJECTIVE:To explore the effect of acupuncture treatment on cerebral ischaemia-reperfusion injury(CIRI)and reveal the underlying mechanism of the effect based on nuclear receptor coactivator 4(NCOA4)mediated ferritinophagy.METHODS:Sprague-Dawley male rats were divided into four groups:the sham group,model group,acupuncture group,and sham acupuncture group.After 2 h of middle cerebral artery occlusion(MCAO),reperfusion was performed for 24 h to induce CIRI.The rats were treated with acupuncture at the Neiguan(PC6)and Shuigou(GV26)acupoints.Their neurological function was evaluated by taking their Bederson scores at 2 h after ischaemia and 24 h after reperfusion.Triphenyltetrazolium chloride staining was applied to assess the cerebral infarct volume at 24 h after reperfusion.The malondialdehyde(MDA)and ferrous iron(Fe^(2+))levels were observed after 24 h of reperfusion using an assay kit.Western blotting was performed to detect the expression of NCOA4 and ferritin heavy chain 1(FTH1)at 24 h after reperfusion.Moreover,the colocalization of ferritin with neurons,NCOA4 with microtubule-associated protein 1 light chain 3(LC3),and NCOA4 with ferritin was visualized using immunofluorescence staining.RESULTS:Acupuncture significantly improved neurological function and decreased cerebral infarct volume in the acupuncture group.Following CIRI,the expression of NCOA4,LC3 and FTH1 was increased,which enhanced ferritinophagy and induced an inappropriate accumulation of Fe^(2+)and MDA in the ischaemic brain.However,acupuncture dramatically downregulated the expression of NCOA4,LC3 and FTH1,inhibited the overactivation of ferritinophagy,and decreased the levels of MDA and Fe^(2+).CONCLUSIONS:Acupuncture can inhibit NCOA4-mediated ferritinophagy and protect neurons against CIRI in a rat model.
基金supported by grants from the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(2015R1A3A2032927 and 2021R1A2C1008130).
文摘Transcriptional coactivators regulate the rate of gene expression in the nucleus.Nuclear receptor coactivator 6(NCOA6),a coactivator,has been implicated in embryonic development,metabolism,and cancer pathogenesis,but its role in innate immunity and inflammatory diseases remains unclear.Here,we demonstrated that NCOA6 was expressed in monocytes and macrophages and that its level was increased under proinflammatory conditions.Unexpectedly,nuclear NCOA6 was found to translocate to the cytoplasm in activated monocytes and then become incorporated into the inflammasome with NLRP3 and ASC,forming cytoplasmic specks.Mechanistically,NCOA6 associated with the ATP hydrolysis motifs in the NACHT domain of NLRP3,promoting the oligomerization of NLRP3 and ASC and thereby instigating the production of IL-1βand active caspase-1.Of note,Ncoa6 deficiency markedly inhibited NLRP3 hyperactivation caused by the Nlrp3^(R258W) gain-of-function mutation in macrophages.Genetic ablation of Ncoa6 substantially attenuated the severity of two NLRP3-dependent diseases,folic-induced acute tubular necrosis and crystal-induced arthritis,in mice.Consistent with these findings,NCOA6 was highly expressed in macrophages derived from gout patients,and NCOA6-positive macrophages were significantly enriched in gout macrophages according to the transcriptome profiling results.Conclusively,NCOA6 is a critical regulator of NLRP3 inflammasome activation and is therefore a promising target for NLRP3-dependent diseases,including gout.
基金supported by the National Natural Science Foundation of China(No.8107165030973503)the Supporting Project for Climbing Scholars in Liaoning Provincial Universities,China(2009-2012)
文摘Objective: To explore the relationship between peroxisome proliferator activated receptor-gamma (PPARγ) and peroxisome proliferator-activated receptor-gamma coactivator-1 (PGC-1) expression in gastric carcinoma (GC), and analyze their correlations with clinicopathological features and clinical outcomes of patients. Methods:The two-step immunohistochemical method was used to detect the expression of PPARγ and PGC-1 in 179 cases of GC, and 108 cases of matched normal gastric mucosa. Besides, 16 cases of fresh GC specimens and corresponding normal gastric mucosa were detected for PGC-1 expression with Western blotting. Results: The positive rates of PPART and PGC-1 expression were significantly lower in GC (54.75%, 49.16%) than in normal gastric mucosa (70.37%, 71.30%), respectively (P〈0.05). The decreased expression of PGC-1 in GC was confirmed ha our Western blot analysis (P=0.004). PPAR7 and PGC-1 expressions were related to Lauren's types ofGC (P〈0.05). Positive correlation was found between PPART and PGC-1 expression in GC (rk=0.422, P〈0.001). The survival time of PPART negative and positive patients was 36.6±3.0 vs. 38.5_+2.7 months, and no statistical difference was found between the 5-year survival rates of two groups (34.4% vs. 44.1%, P=0.522, log-rank test); the survival time of PGC-1 negative and positive patients was 36.2±2.8 vs. 39.9±2.9 months, while no statistical difference was found between the 5-year survival rates of the two groups (32.0% vs. 48.2%, P=0.462, log-rank test) Conclusions'. Decreased expression of PPARγand PGC-1 in GC was related to the Lauren's classification. Their expressions in GC were positively correlated, indicating that their fimctions in gastric carcinogenesis may be closely related.
基金supported by the Russian Science Foundation(Grant No.23-25-00152).
文摘In mammals,the timing of physiological,biochemical and behavioral processes over a 24-h period is controlled by circadian rhythms.To entrain the master clock located in the suprachiasmatic nucleus of the hypothalamus to a precise 24-h rhythm,environmental zeitgebers are used by the circadian system.This is done primarily by signals from the retina via the retinohypothalamic tract,but other cues like exercise,feeding,temperature,anxiety,and social events have also been shown to act as non-photic zeitgebers.The recently identified myokine irisin is proposed to serve as an entraining non-photic signal of exercise.Irisin is a product of cleavage and modification from its precursor membrane fibronectin typeⅢdomain-containing protein 5(FNDC5)in response to exercise.Apart from well-known peripheral effects,such as inducing the"browning"of white adipocytes,irisin can penetrate the blood-brain barrier and display the effects on the brain.Experimental data suggest that FNDC5/irisin mediates the positive effects of physical activity on brain functions.In several brain areas,irisin induces the production of brain-derived neurotrophic factor(BDNF).In the master clock,a significant role in gating photic stimuli in the retinohypothalamic synapse for BDNF is suggested.However,the brain receptor for irisin remains unknown.In the current review,the interactions of physical activity and the irisin/BDNF axis with the circadian system are reconceptualized.