目的观察参芪补肺汤对慢性阻塞性肺疾病(COPD)肺气虚证大鼠支气管平滑肌(ASM)中乙酰化组蛋白H4、组蛋白去乙酰化酶-2(HDAC2)和核因子-κB p65(NF-κB p65)表达的影响。方法取SD大鼠40只,随机分为正常组、模型组、参芪补肺汤组、氨茶碱组...目的观察参芪补肺汤对慢性阻塞性肺疾病(COPD)肺气虚证大鼠支气管平滑肌(ASM)中乙酰化组蛋白H4、组蛋白去乙酰化酶-2(HDAC2)和核因子-κB p65(NF-κB p65)表达的影响。方法取SD大鼠40只,随机分为正常组、模型组、参芪补肺汤组、氨茶碱组,每组10只。运用气管内注射脂多糖加烟熏28 d的方法建立COPD肺气虚证大鼠模型。光镜下观察肺组织的病理形态学变化,运用图像分析法测量小气道管壁和ASM的厚度,采用免疫组化和Western blot方法检测大鼠ASM中乙酰化组蛋白H4、HDAC2和NF-κB p65的蛋白表达,实时荧光定量PCR方法检测大鼠ASM组织中HDAC2 m RNA和NF-κB p65 m RNA的表达。结果与正常组比较,模型组大鼠气道管壁和ASM厚度明显增高(P<0.05);与模型组比较,参芪补肺汤组和氨茶碱组气道管壁和ASM厚度明显降低(P<0.05);参芪补肺汤组与氨茶碱组比较差异无统计学意义(P>0.05)。与正常组比较,模型组乙酰化组蛋白H4的蛋白表达、NF-κB p65 m RNA和蛋白的表达明显增高(P<0.05);HDAC2m RNA和蛋白的表达均明显降低(P<0.05);与模型组比较,参芪补肺汤组和氨茶碱组乙酰化组蛋白H4的蛋白表达、NF-κB p65 m RNA和蛋白的表达明显增高(P<0.05);HDAC2 m RNA和蛋白的表达明显降低(P<0.05)。参芪补肺汤组与氨茶碱组比较差异均无统计学意义(P>0.05)。结论参芪补肺汤可抑制COPD肺气虚证模型大鼠ASM增殖,其机制与其提高HDAC2的表达,使组蛋白H4去乙酰化,从而抑制NF-κB p65的表达有关。展开更多
The quantitative induction of VIN3 by low temperatures is required for PRC2 repression of FLC and promotion of flowering （vernalization） in Arabidopsis. Histone acetylation, a chromatin modification commonly associa...The quantitative induction of VIN3 by low temperatures is required for PRC2 repression of FLC and promotion of flowering （vernalization） in Arabidopsis. Histone acetylation, a chromatin modification commonly associated with gene transcription, increased on VIN3 chromatin in two spatially and temporally distinct phases in response to low temperatures. During short-term cold exposure, histone H3 acetylation at the transcription start site rapidly increased, implying that it is required for VlN3 induction. Subsequent changes in histone H3 and H4 acetylation occurred following continued VIN3 transcription during prolonged cold exposure. Members of the SAGA-like transcriptional adaptor complex, including the histone acetyltransferase GCNS, which induces expression of the cold acclimation pathway genes, do not regulate VlN3 induction during cold exposure, indicating that the cold acclimation pathway and the cold-induction of VlN3 are regulated by different transcriptional mechanisms. Mutations in the other 11 histone acetyltransferase genes did not affect VlN3 induction. However, nicotinamide, a histone deacetyiase inhibitor, induced VIN3 and altered histone acetylation at the VIN3 locus. VIN3 induction was proportional to the length of nicotinamide treatment, which was associated with an early-flowering phenotype and repression of FLC. However, unlike vernalization, the repression of FLC was independent of VIN3 activity. Nicotinamide treatment did not cause a change in the expression of any genes in the autonomous pathway or members of the PRC2 complex, the well characterized repressors of FLC. Our data suggest that FLC is repressed via a novel pathway involving the SIR2 class of histone deacetylases.展开更多
文摘目的观察参芪补肺汤对慢性阻塞性肺疾病(COPD)肺气虚证大鼠支气管平滑肌(ASM)中乙酰化组蛋白H4、组蛋白去乙酰化酶-2(HDAC2)和核因子-κB p65(NF-κB p65)表达的影响。方法取SD大鼠40只,随机分为正常组、模型组、参芪补肺汤组、氨茶碱组,每组10只。运用气管内注射脂多糖加烟熏28 d的方法建立COPD肺气虚证大鼠模型。光镜下观察肺组织的病理形态学变化,运用图像分析法测量小气道管壁和ASM的厚度,采用免疫组化和Western blot方法检测大鼠ASM中乙酰化组蛋白H4、HDAC2和NF-κB p65的蛋白表达,实时荧光定量PCR方法检测大鼠ASM组织中HDAC2 m RNA和NF-κB p65 m RNA的表达。结果与正常组比较,模型组大鼠气道管壁和ASM厚度明显增高(P<0.05);与模型组比较,参芪补肺汤组和氨茶碱组气道管壁和ASM厚度明显降低(P<0.05);参芪补肺汤组与氨茶碱组比较差异无统计学意义(P>0.05)。与正常组比较,模型组乙酰化组蛋白H4的蛋白表达、NF-κB p65 m RNA和蛋白的表达明显增高(P<0.05);HDAC2m RNA和蛋白的表达均明显降低(P<0.05);与模型组比较,参芪补肺汤组和氨茶碱组乙酰化组蛋白H4的蛋白表达、NF-κB p65 m RNA和蛋白的表达明显增高(P<0.05);HDAC2 m RNA和蛋白的表达明显降低(P<0.05)。参芪补肺汤组与氨茶碱组比较差异均无统计学意义(P>0.05)。结论参芪补肺汤可抑制COPD肺气虚证模型大鼠ASM增殖,其机制与其提高HDAC2的表达,使组蛋白H4去乙酰化,从而抑制NF-κB p65的表达有关。
文摘The quantitative induction of VIN3 by low temperatures is required for PRC2 repression of FLC and promotion of flowering （vernalization） in Arabidopsis. Histone acetylation, a chromatin modification commonly associated with gene transcription, increased on VIN3 chromatin in two spatially and temporally distinct phases in response to low temperatures. During short-term cold exposure, histone H3 acetylation at the transcription start site rapidly increased, implying that it is required for VlN3 induction. Subsequent changes in histone H3 and H4 acetylation occurred following continued VIN3 transcription during prolonged cold exposure. Members of the SAGA-like transcriptional adaptor complex, including the histone acetyltransferase GCNS, which induces expression of the cold acclimation pathway genes, do not regulate VlN3 induction during cold exposure, indicating that the cold acclimation pathway and the cold-induction of VlN3 are regulated by different transcriptional mechanisms. Mutations in the other 11 histone acetyltransferase genes did not affect VlN3 induction. However, nicotinamide, a histone deacetyiase inhibitor, induced VIN3 and altered histone acetylation at the VIN3 locus. VIN3 induction was proportional to the length of nicotinamide treatment, which was associated with an early-flowering phenotype and repression of FLC. However, unlike vernalization, the repression of FLC was independent of VIN3 activity. Nicotinamide treatment did not cause a change in the expression of any genes in the autonomous pathway or members of the PRC2 complex, the well characterized repressors of FLC. Our data suggest that FLC is repressed via a novel pathway involving the SIR2 class of histone deacetylases.
