Sonic hedgehog signaling during nervous system development*☆

The Hedgehog signaling pathway plays a key role in embryonic development and organ formation. Sonic hedgehog signaling participates in nervous system development, regulates proliferation and differentiation of neural stem cells, controls growth and targeting of axons, and contributes to specialization of oligodendrocytes. For further studies of the Sonic hedgehog signaling pathway and for the development of new drugs in the treatment of nervous system diseases, it is beneficial to understand these mechanisms.     

局灶性脑缺血大鼠纹状体区域Shh信号通路成分的表达变化及对髓鞘修复的影响

目的检测Sonic Hedgehog(Shh)信号通路及其转录因子Gli1在局灶性脑缺血后不同时间点的表达变化,探讨该通路对脑缺血后髓鞘再生的影响。方法线栓法建立大脑中动脉闭塞(middle cerebral artery occlusion,MCAO)模型,使用免疫组化和RT-PCR的方法观察脑缺血后1 d,3 d,7 d和14 d Shh,Gli1的表达变化。碱性髓鞘蛋白(myelin basic protein,MBP)是髓鞘的组成成分,用作髓鞘的标志物,观察脑缺血后上述各时间点MBP的表达变化。结果正常大鼠Shh和Gli1广泛分布于脑白质和灰质,如皮质,胼胝体和纹状体等区域。Shh和Gli1的表达在脑缺血后3 d~14 d呈逐渐上升趋势。MBP的表达在脑缺血后1 d~28 d逐渐下降。结论脑缺血性损伤可激活Shh信号通路,激活的Shh可能通过调控细胞的增殖参与神经修复,针对Shh的表达量进行干预治疗将为脱髓鞘疾病的治疗提供理论依据。     

Oxidative damage and TGF-β differentially induce lung epithelial cell sonic hedgehog and tenascin-C expression: implications for the regulation of lung remodelling in idiopathic interstitial lung disease

Idiopathic interstitial lung diseases (iILDs) are characterized by inflammation, hyperplasia of Type-II alveolar epithelial cells (AECs) and lung remodelling often with progressive fibrosis. It remains unclear which signals initiate iILD and/or maintain the disease processes. Using real-time RT-PCR and immunohistochemistry on archival biopsies of three patterns of iILD (usual interstitial pneumonitis/UIP, non-specific interstitial pneumonitis/NSIP and cryptogenic organizing pneumonia/COP) we investigated whether hedgehog signalling (previously associated with lung damage and repair) was functional and whether the damage associated extracellular matrix protein tenascin-C was present in activated Type-II AECs in all three iILDs. Using tissue culture, protein and mRNA detection we also determined how two signals (oxidative damage and TGF-β) associated with iILD pathogenesis affected Sonic hedgehog (SHH) and tenascin-C production by a Type-II AEC cell line. We report that SHH pathway and tenascin-C mRNA and proteins were found in UIP, NSIP and COP. SHH signalling was most active at sites of immature organizing fibrous tissue (fibroblastic foci) in UIP. In vitro Type-II AECs constitutively secrete SHH but not tenascin-C. Oxidative injury stimulated SHH release whereas TGF-β inhibited it. TGF-β and oxidative damage both upregulated tenascin-C mRNA but only TGF-β induced synthesis and release of a distinct protein isoform. SHH signalling is active in Type-II AECs from three types of ILD and all three express tenascin-C.     

The effects of molsidomine on hypoxia inducible factor alpha and Sonic hedgehog in testicular ischemia/reperfusion injury in rats

This study was designed to determine the effect of molsidomine (MO), a precursor of nitric oxide (NO) donor, on hypoxia inducible factor alpha (HIF-1α) and Sonic hedgehog (Shh) levels considered to be involved in the development of testes ischemia/reperfusion (I-R) injury. Torsions were created by rotating ipsilateral testes 720° in a clockwise direction for 6 h and 1-h detorsion of the testis was performed. A sham operation was performed in group 1 (control, n = 7). In group 2 (I-R/Untreated, n = 7), following 6 h of unilateral testicular torsion, 1-h detorsion of the testis was performed. No drug was given. In group 3 (I-R/MO), after performing the same surgical procedure as in group 2, a NO donor MO was given at the starting time of reperfusion. In group 4 (I-R/L-NAME), after performing the same surgical procedure as in group 2, L-NAME was given at the starting time of reperfusion. Testes malondialdehyde (MDA) levels were determined as well as examining the testes histologically. Treatment of rats with MO produced a significant reduction in the levels of MDA and histopathological score compared to testes I-R groups. The Sonic hedgehog (Shh) expression in the basement membrane of the tubuli seminiferi, and sertoli and germinal cells in testicular tissue, were greatly increased in the I-R/MO group compared to groups 1, 2 and 4. Additionally, the HIF-1α expression in the interstitial spaces in testicular tissue were greatly increased in the I-R/MO group. The results suggest that MO has a protective effect against ischemia/reperfusion injury in rat testes and may affect Shh and HIF-1α signaling pathway.     

声波与手用器械联合预备后牙感染根管的临床观察

目的评价声波和手用器械联合预备感染的后牙根管的临床效果。方法对129例慢性根尖周炎的155颗后牙,随机分为实验组：76颗,163个根管,用MM1500声波手机及其配套的Rispisonic锉针,结合手用不锈钢K型锉预备根管;对照组：79颗,168个根管,单纯手用不锈钢K型锉预备。两组均用甘油一氢氧化钙糊剂根管内封药消毒,符合根充条件即行根管充填。对两组的疗程次数,根管治疗期间急症发生率,根管充填质量进行比较。结果实验组的疗程次数少于对照组（P〈0．05）;两组的急症发生率、根管充填质量无统计学意义（P〉0．05）。结论用声波器械结合手用器械预备感染的后牙根管,其虽不能提高根管充填质量和减少EIE的发生,但能减少治疗感染根管的疗程次数,具有临床应用的可行性。     

儿童使用声波震动牙刷清除牙菌斑的效果观察

目的:观察儿童使用声波震动牙刷清洁牙及控制菌斑的效果。方法:选择年龄6～7岁的儿童50例,实验组使用声波震动牙刷,对照组使用儿童保健牙刷。采用菌斑染色法记录刷牙前后的菌斑牙面数及菌斑指数(PLI),采用SPSS10.0统计软件包对相关组间数据进行t检验与χ2检验。结果:实验组菌斑清除率为70.22%,对照组为39.08%,声波震动牙刷去除舌面、近中颊面菌斑的能力是手动刷牙的2倍。刷牙前后菌斑指数和菌斑清除率在2组间有高度显著性差异(P<0.001)。结论:声波震动牙刷能有效帮助儿童清除牙面菌斑,是儿童口腔护理的有效工具。     

顺铂联合米托蒽醌调节脑胶质瘤U87细胞Sonic Hedgehog信号通路的研究

目的：观察米托蒽醌（Mitoxantrone,MXT）联合顺铂（Cisplatin,CDDP）对脑胶质瘤U87细胞杀伤活性及对Sonic Hedgehog信号通路的影响。方法：应用MTT法检测不同浓度米托蒽醌、顺铂以及两药物联合对U87细胞成活率的影响。显微镜观察细胞的形态变化DiOC6荧光染料对细胞线粒体染色检测其膜电位变化来反映细胞凋亡。RT-PCR法检测顺铂、米托蒽醌及两药联合对U87细胞Gli1和Ptch基因表达的影响。结果：MTT结果显示顺铂、米托蒽醌均可以有效抑制U87细胞的增殖,当米托蒽醌和顺铂浓度≤0.625μg/ml时,两药联合对U87细胞增殖具有协同抑制作用;细胞形态变化及线粒体膜电位结果显示,单药处理可促进U87细胞凋亡,而联合用药可以协同促进U87细胞的凋亡;RT-PCR法检测显示顺铂对Gli1基因的表达有上调作用,而米托蒽醌、米托蒽醌联合顺铂能下调Ptch和Gli1基因的表达。结论：胶质瘤U87细胞在化疗药物米托蒽醌以及两药物联合作用下可影响Sonic Hedgehog信号通路,协同发挥其促凋亡作用,进而增强肿瘤细胞对化疗药物的敏感性。