Unstable repeats are associated with various types of cancer and have been implicated in more than 40 neurode-generative disorders. Trinucleotide repeats are located in non-coding and coding regions of the genome. Stu...Unstable repeats are associated with various types of cancer and have been implicated in more than 40 neurode-generative disorders. Trinucleotide repeats are located in non-coding and coding regions of the genome. Studies of bacteria, yeast, mice and man have helped to unravel some features of the mechanism of trinucleotide expansion. Looped DNA structures comprising trinucleotide repeats are processed during replication and/or repair to generate deletions or expansions. Most in vivo data are consistent with a model in which expansion and deletion occur by different mechanisms. In mammals, microsatellite instability is complex and appears to be influenced by genetic, epigenetic and developmental factors.展开更多
Background The mitochondrial Na^＋/Ca^2＋ exchanger, NCLX, plays an important role in the balance between Ca2. influx and efflux across the mitochondrial inner membrane in endothelial ceils. Mitochondrial metabolism i...Background The mitochondrial Na^＋/Ca^2＋ exchanger, NCLX, plays an important role in the balance between Ca2. influx and efflux across the mitochondrial inner membrane in endothelial ceils. Mitochondrial metabolism is likely to be affected by the activity of NCLX because Ca^2＋ activates several enzymes of the Krebs cycle. It is currently believed that mitochondria are not only centers of energy produc- tion but are also important sites of reactive oxygen species （ROS） generation and nucleotide-binding oligomerization domain receptor 3 （NLRP3） inflammasome activation. Methods ＆ Results This study focused on NCLX function, in rat aortic endothelial cells （RAECs）, induced by glucose. First, we detected an increase in NCLX expression in the endothelia of rats with diabetes mellitus, which was induced by an injection of streptozotocin. Next, colocalization of NCLX expression and mitochondria was detected using confocal analysis. Suppression of NCLX expression, using an siRNA construct （siNCLX）, enhanced mitochondrial Ca^2＋ influx and blocked efflux induced by glucose. Unexpectedly, silencing of NCLX expression induced increased ROS generation and NLRP3 inflammasome activation. Conclusions These findings suggest that NCLX affects glucose-dependent mitochondrial Ca^2＋ signaling, thereby regulating ROS generation and NLRP3 in- flammasome activation in high glucose conditions. In the early stages of high glucose stimulation, NCLX expression increases to compensate in order to self-protect mitochondrial maintenance, stability, and function in endothelial cells.展开更多
Objective To investigate the effects of stimulant for nucleotide-binding oligomerization domain 1 （NOD1） on secretion of proinflammatory chemokine/cytokines and insulin-dependent glucose uptake in human differentiat...Objective To investigate the effects of stimulant for nucleotide-binding oligomerization domain 1 （NOD1） on secretion of proinflammatory chemokine/cytokines and insulin-dependent glucose uptake in human differentiated adipocytes. Methods Adipose tissues were obtained from patients undergoing liposuction. Stromal vascular cells were extracted and differentiated into adipocytes. A specific ligand for NOD1, was administered to human adipocytes in culture. Nuclear factor-κB transcriptional activity and proinflammatory chemokine/cytokines production were determined by reporter plasmid assay and enzyme-linked immunosorbent assay, respectively. Insulin-stimulated glucose uptake was measured by 2-deoxy-D-[ 3 H] glucose uptake assay. Furthermore, chemokine/cytokine secretion and glucose uptake in adipocytes transfected with small interfering RNA （siRNA） targeting NOD1 upon stimulation of NOD1 ligand were analyzed. Results Nuclear factor-κB transcriptional activity and monocyte chemoattractant protein-1 （MCP-1）, interleukin （IL）-6, and IL-8 secretion in human adipocytes were markedly increased stimulated with NOD1 ligand （all P〈0.01）. Insulin-induced glucose uptake was decreased upon the activation of NOD1 （P〈0.05）. NOD1 gene silencing by siRNA reduced NOD1 ligand-induced MCP-1, IL-6, and IL-8 release and increased insulin-induced glucose uptake （all P〈0.05）. Conclusion NOD1 activation in adipocytes might be implicated in the onset of insulin resistance.展开更多
In eukaryote, nuclear structure is a key component forthe functions of eukaryotic cells. More and more evidencesshow that the nuclear structure plays important role in re-gulating DNA replication. The nuclear structur...In eukaryote, nuclear structure is a key component forthe functions of eukaryotic cells. More and more evidencesshow that the nuclear structure plays important role in re-gulating DNA replication. The nuclear structure providesa physical barrier for the replication licensing, participatesin the decision where DNA replication initiates, and orga-nizes replication proteins as replication factory for DNAreplication. Through these works, new concepts on theregulation of DNA replication have emerged, which willbe discussed in this minireview.展开更多
Objective To investigate the potential role of nucleotide-binding oligomerization domain 1 （NOD1）, a component of the innate immune system, in mediating lipid-induced insulin resistance in adipocytes. Methods Adipo...Objective To investigate the potential role of nucleotide-binding oligomerization domain 1 （NOD1）, a component of the innate immune system, in mediating lipid-induced insulin resistance in adipocytes. Methods Adipocytes from Toll-like receptor 4 deficiency mice were used for stimulation experiments. The effect of oleate/palmitate mixture on nuclear factor-κB （NF-κB） activation was analyzed by reporter plasmid assay. The release of proinflammatory chemokine/cytokines production was determined by using real-time PCR. Insulin-stimulated glucose uptake was measured by 2-deoxy-D-[SH] glucose uptake assay. Chemokine/cytokine expression and glucose uptake in adipocytes transfected with small interfering RNA （siRNA） targeting NOD 1 upon fatty acids treatment were analyzed. Results Oleate/palmitate mixture activated the NF-κB pathway and induced interleukin-6, tumor necrosis factor-R, and monocyte chemoattractant protein-1 mRNA expressions in adipocytes from mice deficient in Toll-like receptor 4, and these effects were blocked by siRNA targeting NOD1. Furthermore, saturated fatty acids decreased the ability of insulin-stimulated glucose uptake. Importantly, siRNA targeting NOD 1 partially reversed saturated fatty acid-induced suppression of insulin-induced glucose uptake. Conclusion NOD1 might play an important role in saturated fatty acid-induced insulin resistance in adipocytes, suggesting a mechanism by which reduced NOD1 activity confers beneficial effects on insulin action.展开更多
A cell-free preparation obtained from extracts of activated Xenopus laevis eggs induced chromatin decondensation and nuclear formation from demembranated Xenopus sperm nuclei. Electron microscopy revealed that the rea...A cell-free preparation obtained from extracts of activated Xenopus laevis eggs induced chromatin decondensation and nuclear formation from demembranated Xenopus sperm nuclei. Electron microscopy revealed that the reassembled nucleus had a double-layered nuclear membrane, nuclear pore complexes, and decondensed chromatin etc. Indirect immunofluorescence analysis demonstrated the presence of lamina in newly assembled nuclei. Western-blotting results showed that lamin LII was present in egg extracts and in lamina of the reassembled nuclei which were previously reported to contain only eggderived lamin LIII.展开更多
Objective: To observe the effect of electroacupuncture (EA) on nuclear factor kappa B (NF-κB) and nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome in uterine tissues of rats with...Objective: To observe the effect of electroacupuncture (EA) on nuclear factor kappa B (NF-κB) and nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome in uterine tissues of rats with primary dysmenorrhea (PD), thus to explore the possible mechanism of EA for PD. Methods: Fifty female Sprague-Dawley (SD) rats were randomly divided into a normal group, a model group, an EA at non-acupoint group, an EA at acupoint group and a Western medicine group, with 10 rats in each group. Except for the normal group, rats in the other four groups were treated with estradiol benzoate combined with oxytocin for 11 d to establish PD rat models. From day 1 of the modeling, rats in the normal group and the model group were only properly grasped without any intervention;Guanyuan (CV 4) and Sanyinjiao (SP 6) were selected for EA treatment in the EA at acupoint group;rats in the EA at non-acupoint group were treated with EA at 5 mm away from the acupoints selected above;rats in the Western medicine group were treated with ibuprofen via gavage. Rats in each group were treated for 10-day successively. On the 11th day, except for the normal group, rats in the other groups were intraperitoneally injected with oxytocin (2 U/rat), and the writhing number within 30 min in each group was compared;the pathological changes in rat uteruses were observed by hematoxylin-eosin (HE) staining, and the pathological damage scores were evaluated. Protein expression levels of NF-κB p65, phospho-NF-κB p65, NLRP3, cysteine aspastic acid-specific protease 1 (caspase-1), interleukin (IL)-1β and IL-18 were detected by Western blot. Results: Compared with the normal group, the writhing number increased significantly (P<0.05), and the extensive exfoliation of the endometrium, severe edema, and histopathological score all increased significantly in the model group (P<0.05) as well as the protein levels of NLRP3, caspase-1, IL-1β and IL-18, and the ratio of phospho-NF-κB p65/NF-κB p65 in rat uterine tissues (all P<0.05);compared with the model group, the numbers of writhing reaction decreased within 30 min (P<0.05), the endometrial exfoliation was rare, the edema degree was mild, and the histopathological scores decreased significantly (all P<0.05) in the EA at acupoint group and the Western medicine group;compared with the model group, the phospho-NF-κB p65/NF-κB p65 ratio and the NLRP3, caspase-1, IL-1β and IL-18 protein levels of rat uterine tissues in the EA at acupoint group were significantly lower (P<0.05);compared with the model group, the caspase-1, IL-1β and IL-18 protein levels of the rat uterine tissues decreased significantly (all P<0.05), and the differences in the NLRP3 and phospho-NF-κB p65/NF-κB p65 levels were statistically insignificant (all P>0.05) in the Western medicine group;compared with the Western medicine group, the phospho-NF-κB p65/NF-κB p65 ratio, also the NLRP3, IL-1β and IL-18 protein levels of the uterine tissues decreased significantly in the EA at acupoint group (all P<0.05), while the difference in the caspase-1 level was statistically insignificant (P>0.05);there were no significant differences between the EA at non-acupoint group and the model group in any indicators (all P>0.05). Conclusion: EA at acupoints significantly improves the pain and pathological damages of PD rats. The mechanism may be related to the reduced uterine inflammation via inhibiting NF-κB phosphorylation and NLRP3 activation in uteruses of PD rats.展开更多
文摘Unstable repeats are associated with various types of cancer and have been implicated in more than 40 neurode-generative disorders. Trinucleotide repeats are located in non-coding and coding regions of the genome. Studies of bacteria, yeast, mice and man have helped to unravel some features of the mechanism of trinucleotide expansion. Looped DNA structures comprising trinucleotide repeats are processed during replication and/or repair to generate deletions or expansions. Most in vivo data are consistent with a model in which expansion and deletion occur by different mechanisms. In mammals, microsatellite instability is complex and appears to be influenced by genetic, epigenetic and developmental factors.
基金This work was supported by the National Natural Science Foundation of China （Grant No. 81173625, 81373458） Thanks for the kind help of Dr. Wang （Pulmonary Division, Boston Children＇s Hospital, MA, USA）, who was extremely helpful in the revision of the language.
文摘Background The mitochondrial Na^＋/Ca^2＋ exchanger, NCLX, plays an important role in the balance between Ca2. influx and efflux across the mitochondrial inner membrane in endothelial ceils. Mitochondrial metabolism is likely to be affected by the activity of NCLX because Ca^2＋ activates several enzymes of the Krebs cycle. It is currently believed that mitochondria are not only centers of energy produc- tion but are also important sites of reactive oxygen species （ROS） generation and nucleotide-binding oligomerization domain receptor 3 （NLRP3） inflammasome activation. Methods ＆ Results This study focused on NCLX function, in rat aortic endothelial cells （RAECs）, induced by glucose. First, we detected an increase in NCLX expression in the endothelia of rats with diabetes mellitus, which was induced by an injection of streptozotocin. Next, colocalization of NCLX expression and mitochondria was detected using confocal analysis. Suppression of NCLX expression, using an siRNA construct （siNCLX）, enhanced mitochondrial Ca^2＋ influx and blocked efflux induced by glucose. Unexpectedly, silencing of NCLX expression induced increased ROS generation and NLRP3 inflammasome activation. Conclusions These findings suggest that NCLX affects glucose-dependent mitochondrial Ca^2＋ signaling, thereby regulating ROS generation and NLRP3 in- flammasome activation in high glucose conditions. In the early stages of high glucose stimulation, NCLX expression increases to compensate in order to self-protect mitochondrial maintenance, stability, and function in endothelial cells.
基金Supported by Grant from Department of Education of Liaoning Province(2008810)
文摘Objective To investigate the effects of stimulant for nucleotide-binding oligomerization domain 1 （NOD1） on secretion of proinflammatory chemokine/cytokines and insulin-dependent glucose uptake in human differentiated adipocytes. Methods Adipose tissues were obtained from patients undergoing liposuction. Stromal vascular cells were extracted and differentiated into adipocytes. A specific ligand for NOD1, was administered to human adipocytes in culture. Nuclear factor-κB transcriptional activity and proinflammatory chemokine/cytokines production were determined by reporter plasmid assay and enzyme-linked immunosorbent assay, respectively. Insulin-stimulated glucose uptake was measured by 2-deoxy-D-[ 3 H] glucose uptake assay. Furthermore, chemokine/cytokine secretion and glucose uptake in adipocytes transfected with small interfering RNA （siRNA） targeting NOD1 upon stimulation of NOD1 ligand were analyzed. Results Nuclear factor-κB transcriptional activity and monocyte chemoattractant protein-1 （MCP-1）, interleukin （IL）-6, and IL-8 secretion in human adipocytes were markedly increased stimulated with NOD1 ligand （all P〈0.01）. Insulin-induced glucose uptake was decreased upon the activation of NOD1 （P〈0.05）. NOD1 gene silencing by siRNA reduced NOD1 ligand-induced MCP-1, IL-6, and IL-8 release and increased insulin-induced glucose uptake （all P〈0.05）. Conclusion NOD1 activation in adipocytes might be implicated in the onset of insulin resistance.
文摘In eukaryote, nuclear structure is a key component forthe functions of eukaryotic cells. More and more evidencesshow that the nuclear structure plays important role in re-gulating DNA replication. The nuclear structure providesa physical barrier for the replication licensing, participatesin the decision where DNA replication initiates, and orga-nizes replication proteins as replication factory for DNAreplication. Through these works, new concepts on theregulation of DNA replication have emerged, which willbe discussed in this minireview.
基金Supported by the Grant from the Educational Department of Liaoning Province(2008810)
文摘Objective To investigate the potential role of nucleotide-binding oligomerization domain 1 （NOD1）, a component of the innate immune system, in mediating lipid-induced insulin resistance in adipocytes. Methods Adipocytes from Toll-like receptor 4 deficiency mice were used for stimulation experiments. The effect of oleate/palmitate mixture on nuclear factor-κB （NF-κB） activation was analyzed by reporter plasmid assay. The release of proinflammatory chemokine/cytokines production was determined by using real-time PCR. Insulin-stimulated glucose uptake was measured by 2-deoxy-D-[SH] glucose uptake assay. Chemokine/cytokine expression and glucose uptake in adipocytes transfected with small interfering RNA （siRNA） targeting NOD 1 upon fatty acids treatment were analyzed. Results Oleate/palmitate mixture activated the NF-κB pathway and induced interleukin-6, tumor necrosis factor-R, and monocyte chemoattractant protein-1 mRNA expressions in adipocytes from mice deficient in Toll-like receptor 4, and these effects were blocked by siRNA targeting NOD1. Furthermore, saturated fatty acids decreased the ability of insulin-stimulated glucose uptake. Importantly, siRNA targeting NOD 1 partially reversed saturated fatty acid-induced suppression of insulin-induced glucose uptake. Conclusion NOD1 might play an important role in saturated fatty acid-induced insulin resistance in adipocytes, suggesting a mechanism by which reduced NOD1 activity confers beneficial effects on insulin action.
文摘A cell-free preparation obtained from extracts of activated Xenopus laevis eggs induced chromatin decondensation and nuclear formation from demembranated Xenopus sperm nuclei. Electron microscopy revealed that the reassembled nucleus had a double-layered nuclear membrane, nuclear pore complexes, and decondensed chromatin etc. Indirect immunofluorescence analysis demonstrated the presence of lamina in newly assembled nuclei. Western-blotting results showed that lamin LII was present in egg extracts and in lamina of the reassembled nuclei which were previously reported to contain only eggderived lamin LIII.
文摘Objective: To observe the effect of electroacupuncture (EA) on nuclear factor kappa B (NF-κB) and nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome in uterine tissues of rats with primary dysmenorrhea (PD), thus to explore the possible mechanism of EA for PD. Methods: Fifty female Sprague-Dawley (SD) rats were randomly divided into a normal group, a model group, an EA at non-acupoint group, an EA at acupoint group and a Western medicine group, with 10 rats in each group. Except for the normal group, rats in the other four groups were treated with estradiol benzoate combined with oxytocin for 11 d to establish PD rat models. From day 1 of the modeling, rats in the normal group and the model group were only properly grasped without any intervention;Guanyuan (CV 4) and Sanyinjiao (SP 6) were selected for EA treatment in the EA at acupoint group;rats in the EA at non-acupoint group were treated with EA at 5 mm away from the acupoints selected above;rats in the Western medicine group were treated with ibuprofen via gavage. Rats in each group were treated for 10-day successively. On the 11th day, except for the normal group, rats in the other groups were intraperitoneally injected with oxytocin (2 U/rat), and the writhing number within 30 min in each group was compared;the pathological changes in rat uteruses were observed by hematoxylin-eosin (HE) staining, and the pathological damage scores were evaluated. Protein expression levels of NF-κB p65, phospho-NF-κB p65, NLRP3, cysteine aspastic acid-specific protease 1 (caspase-1), interleukin (IL)-1β and IL-18 were detected by Western blot. Results: Compared with the normal group, the writhing number increased significantly (P<0.05), and the extensive exfoliation of the endometrium, severe edema, and histopathological score all increased significantly in the model group (P<0.05) as well as the protein levels of NLRP3, caspase-1, IL-1β and IL-18, and the ratio of phospho-NF-κB p65/NF-κB p65 in rat uterine tissues (all P<0.05);compared with the model group, the numbers of writhing reaction decreased within 30 min (P<0.05), the endometrial exfoliation was rare, the edema degree was mild, and the histopathological scores decreased significantly (all P<0.05) in the EA at acupoint group and the Western medicine group;compared with the model group, the phospho-NF-κB p65/NF-κB p65 ratio and the NLRP3, caspase-1, IL-1β and IL-18 protein levels of rat uterine tissues in the EA at acupoint group were significantly lower (P<0.05);compared with the model group, the caspase-1, IL-1β and IL-18 protein levels of the rat uterine tissues decreased significantly (all P<0.05), and the differences in the NLRP3 and phospho-NF-κB p65/NF-κB p65 levels were statistically insignificant (all P>0.05) in the Western medicine group;compared with the Western medicine group, the phospho-NF-κB p65/NF-κB p65 ratio, also the NLRP3, IL-1β and IL-18 protein levels of the uterine tissues decreased significantly in the EA at acupoint group (all P<0.05), while the difference in the caspase-1 level was statistically insignificant (P>0.05);there were no significant differences between the EA at non-acupoint group and the model group in any indicators (all P>0.05). Conclusion: EA at acupoints significantly improves the pain and pathological damages of PD rats. The mechanism may be related to the reduced uterine inflammation via inhibiting NF-κB phosphorylation and NLRP3 activation in uteruses of PD rats.
