Naive CD4 T cells can differentiate into at least two different types ofT helpers, Thl and Th2 cells. Th2 cells, capable of producing IL-4, IL-5 and IL-13, are involved in humoral immunity against extracellular pathog...Naive CD4 T cells can differentiate into at least two different types ofT helpers, Thl and Th2 cells. Th2 cells, capable of producing IL-4, IL-5 and IL-13, are involved in humoral immunity against extracellular pathogens and in the induction of asthma and other allergic diseases. In this review, we summarize recent reports regarding the transcription factors involved in Th2 differentiation and cell expansion, including StatS, Gfi- 1 and GATA-3. Stats activation is necessary and sufficient for IL-2-mediated function in Th2 differentiation. Enhanced Stats signaling induces Th2 differentiation independent of IL-4 signaling; although it does not up-regulate GATA-3 expression, it does require the presence of GATA-3 for its action. Gfi-1, induced by IL-4, promotes the expansion of GATA-3-expressing cells. Analysis of conditional Gata3 knockout mice confirmed the critical role of GATA-3 in Th2 cell differentiation （both IL-4 dependent and IL-4 independent） and in Th2 cell proliferation and also showed the importance of basal GATA-3 expression in inhibiting Thl differentiation.展开更多
MicroRNAs （miRNAs）, which are small noncoding RNA molecules, play important roles in the post-transcriptional regulation process. The microRNA-21 gene （miR-21） has been reported to be highly expressed in various s...MicroRNAs （miRNAs）, which are small noncoding RNA molecules, play important roles in the post-transcriptional regulation process. The microRNA-21 gene （miR-21） has been reported to be highly expressed in various solid tumors, including breast cancer. Bone morphogenetic protein-6 （BMP-6） has been identified as an inhibitor of breast cancer epithelial-mesenchymal transition （EMT） through rescuing E-cadherin expression. We initiated experi- ments to identify the relationships between miR-21 and BMP-6 in breast cancer progression. Real-time PCR analysis showed that miR-21 expression was very high in MDA-MB-231 cells that expressed little BMP-6. A reverse correla- tion between BMP-6 and miR-21 was also determined in breast cancer tissue samples. Moreover, BMP-6 inhibited miR-21 transcription in MDA-MB-231 cells. In order to investigate how BMP-6 inhibited the miR-21 promoter （miPPR-21）, we constructed a series of miPPR-21 reporters. Luciferase assay results indicated that BMP-6 inhibited miPPR-21 activity through the E2-box and AP-l-binding sites. We also demonstrated that both δEF1 and TPA in- duced miR-21 expression. Using site-directed mutation and CHIP assay, we found that δEF1 induced miPPR-21 ac- tivity by binding to the E2-box on miPPR-21. Moreover, TPA triggered miPPR-21 activity through the AP-I binding sites. BMP-6 treatment significantly reduced the binding of these factors to miPPR-21 by decreasing the expression of δEF1 and c-Fos/c-Jun. We also demonstrated that BMP-6-induced downregulation of miR-21 modified the activ- ity of PDCD4 3＇UTR and inhibited MDA-MB-231 cell invasion. δEF1 overexpression and TPA induction blocked this inhibitory effect of BMP-6. In conclusion, BMP-6-induced inhibition of miR-21 suggests that BMP-6 may function as an anti-metastasis factor by a mechanism involving transcriptional repression of miR-21 in breast cancer.展开更多
This study aims to elucidate the mechanisms by which dexmedetomidine alleviates pulmonary edema in rats with acute lung injury induced by lipopolysaccharide （LPS）. Male Wistar rats were randomly divided into five gr...This study aims to elucidate the mechanisms by which dexmedetomidine alleviates pulmonary edema in rats with acute lung injury induced by lipopolysaccharide （LPS）. Male Wistar rats were randomly divided into five groups： normal saline control （NS） group, receiving intravenous 0.9% normal saline （5 mL/kg）; LPS group, receiving intravenous LPS （10 mg/kg）; small-dose dexmedetomidine （S） group, treated with a small dose of dexmedetomidine （0.5 μg·kg^-1·h^-1）; medium-dose dexmedetomidine （M） group, treated with a medium dose of dexmedetomidine （2.5 μg·kg^-1·h^-1）; high-dose dexmedetomidine （H） group, treated with a high dose of dexmedetomidine （5μg·kg^-1·h^-1）. The rats were sacrificed 6 h after intravenous injection of LPS or NS, and the hmgs were removed for evaluating histological characteristics and determining the lung wet/dry weight ratio （W/D）. The levels of tumor necrosis factor-alpha （TNF-α） and interleukin-1β （IL-1β） in the lung tissues were assessed by enzyme-linked immunosorbent assay （ELISA）. The mRNA and protein expression levels of aquaporin-1 （AQP1） and aquaporin-5 （AQP5） were detected by RT-PCR, immunohistochemistry, and Western blot- ting. The lung tissues from the LPS groups were significantly damaged, which were less pronounced in the H group but not in the small-dose dexmedetomidine group or medium-dose dexmedetomidine group. The W/D and the concentrations of TNF-α and IL-1β in the pulmonary tissues were increased in the LPS group as compared with those in NS group, which were reduced in the H group but not in S group or M group （P〈0.01）. The expression of AQP1 and AQP5 was lower in the LPS group than in the NS group, and significantly increased in the H group but not in the S group or M group （P〈0.01）. Our findings suggest that dexmedetomidine may alleviate pulmonary edema by increasing the expression of AQP-1 and AQP-5.展开更多
文摘Naive CD4 T cells can differentiate into at least two different types ofT helpers, Thl and Th2 cells. Th2 cells, capable of producing IL-4, IL-5 and IL-13, are involved in humoral immunity against extracellular pathogens and in the induction of asthma and other allergic diseases. In this review, we summarize recent reports regarding the transcription factors involved in Th2 differentiation and cell expansion, including StatS, Gfi- 1 and GATA-3. Stats activation is necessary and sufficient for IL-2-mediated function in Th2 differentiation. Enhanced Stats signaling induces Th2 differentiation independent of IL-4 signaling; although it does not up-regulate GATA-3 expression, it does require the presence of GATA-3 for its action. Gfi-1, induced by IL-4, promotes the expansion of GATA-3-expressing cells. Analysis of conditional Gata3 knockout mice confirmed the critical role of GATA-3 in Th2 cell differentiation （both IL-4 dependent and IL-4 independent） and in Th2 cell proliferation and also showed the importance of basal GATA-3 expression in inhibiting Thl differentiation.
文摘MicroRNAs （miRNAs）, which are small noncoding RNA molecules, play important roles in the post-transcriptional regulation process. The microRNA-21 gene （miR-21） has been reported to be highly expressed in various solid tumors, including breast cancer. Bone morphogenetic protein-6 （BMP-6） has been identified as an inhibitor of breast cancer epithelial-mesenchymal transition （EMT） through rescuing E-cadherin expression. We initiated experi- ments to identify the relationships between miR-21 and BMP-6 in breast cancer progression. Real-time PCR analysis showed that miR-21 expression was very high in MDA-MB-231 cells that expressed little BMP-6. A reverse correla- tion between BMP-6 and miR-21 was also determined in breast cancer tissue samples. Moreover, BMP-6 inhibited miR-21 transcription in MDA-MB-231 cells. In order to investigate how BMP-6 inhibited the miR-21 promoter （miPPR-21）, we constructed a series of miPPR-21 reporters. Luciferase assay results indicated that BMP-6 inhibited miPPR-21 activity through the E2-box and AP-l-binding sites. We also demonstrated that both δEF1 and TPA in- duced miR-21 expression. Using site-directed mutation and CHIP assay, we found that δEF1 induced miPPR-21 ac- tivity by binding to the E2-box on miPPR-21. Moreover, TPA triggered miPPR-21 activity through the AP-I binding sites. BMP-6 treatment significantly reduced the binding of these factors to miPPR-21 by decreasing the expression of δEF1 and c-Fos/c-Jun. We also demonstrated that BMP-6-induced downregulation of miR-21 modified the activ- ity of PDCD4 3＇UTR and inhibited MDA-MB-231 cell invasion. δEF1 overexpression and TPA induction blocked this inhibitory effect of BMP-6. In conclusion, BMP-6-induced inhibition of miR-21 suggests that BMP-6 may function as an anti-metastasis factor by a mechanism involving transcriptional repression of miR-21 in breast cancer.
基金supported by a grant from Technical Research and Development Fund of Shenzhen(No.JCYJ20140416122812032)
文摘This study aims to elucidate the mechanisms by which dexmedetomidine alleviates pulmonary edema in rats with acute lung injury induced by lipopolysaccharide （LPS）. Male Wistar rats were randomly divided into five groups： normal saline control （NS） group, receiving intravenous 0.9% normal saline （5 mL/kg）; LPS group, receiving intravenous LPS （10 mg/kg）; small-dose dexmedetomidine （S） group, treated with a small dose of dexmedetomidine （0.5 μg·kg^-1·h^-1）; medium-dose dexmedetomidine （M） group, treated with a medium dose of dexmedetomidine （2.5 μg·kg^-1·h^-1）; high-dose dexmedetomidine （H） group, treated with a high dose of dexmedetomidine （5μg·kg^-1·h^-1）. The rats were sacrificed 6 h after intravenous injection of LPS or NS, and the hmgs were removed for evaluating histological characteristics and determining the lung wet/dry weight ratio （W/D）. The levels of tumor necrosis factor-alpha （TNF-α） and interleukin-1β （IL-1β） in the lung tissues were assessed by enzyme-linked immunosorbent assay （ELISA）. The mRNA and protein expression levels of aquaporin-1 （AQP1） and aquaporin-5 （AQP5） were detected by RT-PCR, immunohistochemistry, and Western blot- ting. The lung tissues from the LPS groups were significantly damaged, which were less pronounced in the H group but not in the small-dose dexmedetomidine group or medium-dose dexmedetomidine group. The W/D and the concentrations of TNF-α and IL-1β in the pulmonary tissues were increased in the LPS group as compared with those in NS group, which were reduced in the H group but not in S group or M group （P〈0.01）. The expression of AQP1 and AQP5 was lower in the LPS group than in the NS group, and significantly increased in the H group but not in the S group or M group （P〈0.01）. Our findings suggest that dexmedetomidine may alleviate pulmonary edema by increasing the expression of AQP-1 and AQP-5.
文摘目的探讨加味丹参饮预处理是否通过调节Beclin-1和Atg5表达调控自噬抗缺血再灌注损伤大鼠心肌。方法将60只健康SD大鼠随机分为空白对照(control group,C)组、假手术(sham,S)组、缺血再灌注损伤(ischemia reperfusion injury,IRI)组、IRI+加味丹参饮(Jiawei Danshen Yin,JDY)组、IRI+JDY+自噬抑制剂(inhibitor,I)组,每组12只。通过结扎-放松大鼠左冠状动脉前降支制备心肌IRI模型。通过氯化三苯基四氮唑(TTC)染色观察心肌梗死面积率;在透射电镜下观察自噬泡;采用实时荧光定量逆转录-聚合酶链反应(reverse transcription-polymerase chain reaction,RT-PCR)方法检测心肌Beclin-1和Atg5 m RNA表达;采用蛋白质印迹(western blot)法检测心肌Beclin-1蛋白表达变化。结果 IRI+JDY组心肌梗死面积率显著低于IRI组及IRI+JDY+I组(P<0.01)。电镜结果显示,IRI+JDY组适度调节大鼠缺血再灌注损伤心肌细胞的自噬,改善心肌细胞结构。IRI组大鼠心肌细胞中Beclin-1和Atg5 m RNA表达水平及Beclin-1蛋白表达较SG组显著升高(P<0.01);IRI+JDY组、IRI+JDY+I组大鼠心肌细胞中Beclin-1和Atg5 m RNA表达水平及Beclin-1蛋白表达较IRI组显著降低(P<0.01);IRI+JDY组大鼠心肌细胞中Beclin-1和Atg5 m RNA表达水平及Beclin-1蛋白表达较IRI+JDY+I组显著升高(P<0.01)。结论加味丹参饮通过调节缺血再灌注损伤大鼠心肌细胞自噬相关基因Beclin-1和Atg5表达适度,调控缺血再灌注心肌细胞发生适度自噬,从而发挥细胞保护作用。
