A direct requirement for Hedgehog signaling for normal specification of all ventral progenitor domains in the presumptive mammalian spinal cord

The hedgehog signaling pathway organizes the developing ventral neural tube by establishing distinct neural progenitor fates along the dorsoventral axis. Smoothened (Smo) is essential for all Hedgehog (Hh) signaling, and genetic inactivation of Smo cells autonomously blocks the ability of cells to transduce the Hh signal. Using a chimeric approach, we examined the behavior of Smo null mutant neural progenitor cells in the developing vertebrate spinal cord, and we show that direct Hh signaling is essential for the specification of all ventral progenitor populations. Further, Hh signaling extends into the dorsal half of the spinal cord including the intermediate Dbx expression domain. Surprisingly, in the absence of Sonic hedgehog (Shh), we observe the presence of a Smo-dependent Hh signaling activity operating in the ventral half of the spinal cord that most likely reflects Indian hedgehog (Ihh) signaling originating from the underlying gut endoderm. Comparative studies of Shh, Smo, and Gli3 single and compound mutants reveal that Hh signaling acts in part to specify neural cell identity by counteracting the repressive action of Gli3 on p0, p1, p2, and pMN formation. However, whereas these cell identities are restored in Gli3/Smo compound mutants, correct stratification of the rescued ventral cell types is lost. Thus, Hh signaling is essential for organizing ventral cell pattern, possibly through the control of differential cell affinities.     

干扰维生素D3上调蛋白1通过调控Shh影响高糖诱导的肾小管上皮细胞凋亡

目的:探讨维生素D3上调蛋白1(VDUP-1)对高糖诱导的肾小管上皮细胞凋亡的影响及机制。方法:人近端肾小管上皮HK-2细胞用高糖处理后,real-time PCR和Western blot检测细胞中VDUP-1的水平。HK-2细胞转染VDUP-1小干扰RNA,real-time PCR和Western blot检测抑制效果。高糖条件培养VDUP-1表达下调的HK-2细胞,流式细胞术检测细胞凋亡,试剂盒检测细胞中caspase-3和caspase-9的活性,ELISA法测定培养上清液中肿瘤坏死因子α(TNF-α)含量,Western blot检测细胞中音猬因子(Shh)信号通路关键蛋白Patched 1 (Ptch1)、Smoothened (Smo)、锌指蛋白Gli2和Shh的水平。用外源性Shh处理HK-2细胞,Western blot检测Ptch1、Smo和Gli2的水平。用外源性Shh处理VDUP-1表达下调的HK-2细胞,高糖处理后,流式细胞术检测细胞凋亡,试剂盒检测细胞中caspase-3和caspase-9的活性,ELISA法测定培养液上清中TNF-α含量。结果:高糖处理后,HK-2细胞中VDUP-1的mRNA和蛋白水平升高(P 0. 05)。转染VDUP-1小干扰RNA后,HK-2细胞中VDUP-1的mRNA和蛋白水平下降(P 0. 05)。与正常培养的细胞相比,高糖处理后HK-2细胞凋亡率显著升高,细胞中caspase-3和caspase-9活性明显升高,TNF-α含量亦明显升高(P 0. 05);下调VDUP-1表达后的HK-2细胞经高糖处理后细胞凋亡率显著降低,细胞中caspase-3和caspase-9活性也明显降低(P 0. 05)。高糖培养后细胞中Ptch1、Smo、Gli2和Shh的蛋白水平下降,而下调VDUP-1表达部分拮抗高糖对HK-2细胞中Ptch1、Smo、Gli2和Shh表达的影响。外源性Shh可以促进细胞中Ptch1、Smo和Gli2的表达,抑制高糖诱导的HK-2细胞凋亡和分泌TNF-α,与下调VDUP-1共同抑制高糖诱导的肾小管上皮细胞凋亡。结论:干扰VDUP-1表达可能通过激活Shh信号通路抑制高糖诱导的肾小管上皮细胞凋亡和分泌TNF-α。     

Sonic hedgehog信号通路在单侧输尿管梗阻大鼠肾组织中的表达变化及意义

 目的：探讨Sonic hedgehog（Shh）信号通路在单侧输尿管梗阻（UUO）大鼠肾组织中的表达变化及意义。方法：将48只SD大鼠随机分为UUO模型组（n=24）和假手术组（n=24）,梗阻术3、7和14 d后取其梗阻侧肾脏组织。用HE和Masson染色检测肾间质纤维化程度,免疫组织化学染色检测Shh通路分子Shh、Ptch1、Smo、Gli1及III型胶原的蛋白表达,酶联免疫吸附实验（ELISA）检测肾组织中TGF-β₁和Shh含量,real-time RT-PCR检测TGF-β₁、I和III型胶原及Shh通路分子mRNA表达。结果：HE和Masson染色显示,梗阻侧肾组织出现明显的纤维化病变,且随时间延长而加剧。TGF-β₁、I和III型胶原含量在梗阻肾中表达明显增高（P<0.05）。同时,Shh信号通路分子Shh、Smo和Gli mRNA和蛋白在梗阻肾中表达明显升高（P<0.05）,而Ptch1 mRNA和蛋白的表达下调（P<0.01）,提示Shh信号被激活。相关分析表明,Shh信号起始信号Shh水平的升高与TGF-β₁含量增加呈明显的相关。结论：UUO大鼠诱导肾间质纤维化发生过程中,Shh信号通路分子被激活,推测可能的机制是活化的Shh信号通路诱导TGF-β₁表达和释放,导致肾间质纤维化。     

SD大鼠肝细胞癌模型Hedgehog信号通路与复方苦参干预后的效应

背景：有研究表明在人类肝细胞癌中存在Hedgehog信号通路异常激活,但在动物肝细胞癌中Hedgehog信号通路是否激活尚不清楚。苦参可抑制肝癌细胞增殖周期,但其与Hedgehog信号通路的关系少见报道。 目的：观察Hedgehog信号通路在人工诱导SD大鼠肝细胞癌中的作用,以及复方苦参药物对Hedgehog信号通路影响。 方法：二乙基亚硝胺诱导SD大鼠建立肝细胞癌大鼠模型后,随机分为模型组、低剂量苦参组和高剂量苦参组,并设立空白对照组。建模后15周,分别在低、高剂量苦参组腹腔注射30,90 mg/(kg•d)复方苦参治疗3周后,应用免疫组织化学染色和RT-PCR法检测这所有大鼠组织中在Hedgehog信号通路中靶基因转录因子Gli2和跨膜蛋白受体复合物Ptch的表达情况。 结果与结论：相比对照组,模型组、低剂量和高剂量苦参组肝癌组织中Gli2和Ptch均呈高表达(P < 0.01)。结果提示,在人工诱导的SD大鼠肝癌模型中,Hedgehog信号通路处于激活状态。在给予高低剂量复方苦参干预下,Hedgehog信号通路靶基因转录因子Gli2和跨膜蛋白受体复合物Ptch呈高表达。     

基于Hedgehog通路探讨补肾活血方对实验性膝骨性关节炎兔退变软骨的保护作用

目的:探究补肾活血方(BSHX)对实验性膝骨性关节炎兔退变软骨的保护作用及其可能的机制。方法:将新西兰兔分为对照(control)组、模型(model)组、BSHX(1. 86 g/kg)组、Hedgehog通路激活剂SAG(20 mg/kg)组和BSHX+SAG组,每组6只。测定兔膝关节宽度,处死兔后观察膝关节软骨大体情况,对软骨退变情况进行评定;HE染色和番红O染色观察膝关节软骨组织病理形态学变化;ELISA法检测软骨组织中肿瘤坏死因子α(TNF-α)和白细胞介素1β(IL-1β)水平;免疫组化法检测软骨组织中基质金属蛋白酶13(MMP-13)和II型胶原(Col-II)蛋白表达;Western blot法检测软骨组织中Shh、Ptch1、Smo和Gli1蛋白表达。结果:与control组相比,model组膝关节宽度增大,软骨退变评分、软骨分级和Mankin评分升高,软骨组织中TNF-α和IL-1β水平升高,MMP-13阳性表达率升高,Col-II阳性表达率降低,Shh、Ptch1、Smo和Gli1蛋白表达升高(P<0. 05)。与model组相比,BSHX组膝关节宽度减小,...     

Hedgehog signaling regulates proliferation of prostate cancer cells via stathmin1

Hedgehog (Hh) signaling is an essential pathway in embryonic development of prostate. Hh also plays roles in the proliferation of progenitor cells and cancer cells of adult prostate. However, how Hh signaling contributes to carcinogenesis of prostate is poorly understood. Stathmin1 is a microtubule-regulating protein that plays an important role in the assembly and disassembly of the mitotic spindle. Stathmin1 is expressed in normal developing mouse prostate and in prostate cancer. The expression pattern of stathmin1 is similar to that of Shh in prostate development and cancer, suggesting a connection between these two proteins. In this study, we examined the relationship between stathmin1 and Hh signaling. Here, we show that stathmin1 expression is regulated by Hh signaling in prostate cancer cells. Cyclopamine, a specific inhibitor of Hh signaling, reduced the expression of stathmin1 in prostate cancer cells. However, the Shh peptide induced stathmin1 expression. Overexpression of Gli1 further confirmed the relationship. Co-expression of stathmin1 and Patched 1, a receptor for Hh signaling was observed in prostate cancer tissues. Cyclopamine and stathmin1 siRNA both decreased proliferation of prostate cancer cells but did not produce an additive effect, suggesting a common pathway. These results suggest that Hh signaling regulates proliferation of prostate cancer cells by controlling stathmin1 expression.     

Hedgehog signaling is involved in differentiation of normal colonic tissue rather than in tumor proliferation

The Hedgehog (Hh) pathway is a main regulation cascade in embryonic differentiation. It is also present in adult tissues and unusual expression has been associated with formation of benign and malignant lesions. We examined the presence of the Hedgehog pathway in normal and pathological human colon tissue. Components investigated include Sonic (Shh), Indian (Ihh), and Desert Hedgehog (Dhh), Gli1, Gli2, Gli3, and Patched (Ptch). Pathological tissue samples comprised 23 benign and 20 malignant lesions of human colon. The influence of the Hedgehog pathway on differentiation and proliferation has been investigated by analyzing the effect of the pathway inhibitor Cyclopamine on human colon cancer cell lines HT29 and CaCo2. In normal colon, we detected expression of Shh and Dhh within the lining epithelium and Patched, Gli1, and Gli2 along the whole crypts. Within all benign lesions, positive staining of Shh, Dhh, Gli1, Gli2, and Ptch was detected. Expression of Shh and Dhh was restricted to single cell aggregates. Malignant lesions also displayed focal staining pattern for Shh and Dhh but to a much lesser extent. We conclude that Hedgehog signaling is involved rather in constant differentiation and renewing of the colonic lining epithelium than in cancer formation, growth, or proliferation.     

子宫颈癌中Hedgehog信号通路蛋白表达与人乳头状瘤病毒16型感染的关系

目的 探讨Hedgehog(Hh)信号通路蛋白在宫颈癌及其癌前病变中的临床病理学意义,并分析其与人乳头状瘤病毒(HPV)16型感染的关系.方法 32例正常宫颈上皮、71例宫颈上皮内瘤变(CIN;CIN Ⅰ 28例,CIN Ⅱ 18例,CIN Ⅲ25例)和80例宫颈鳞状细胞癌共183例选自延边大学医院、延边妇幼保健院和延边肿瘤医院病理科存档蜡块.应用PCR技术检测上述组织中HPV16型的感染情况,并应用Shh、Ihh、Ptch和Smo 4种Hh信号通路蛋白抗体、组织芯片和免疫组织化学EnVision法检测Hh信号通路蛋白在上述病变组织中的表达情况.结果 Shh、Ihh、Ptch和Smo在正常宫颈黏膜上皮中为弱阳性,而在宫颈癌和CIN Ⅲ中呈强阳性,其表达率均显著高于正常宫颈黏膜上皮(P均<0.05).80例官颈癌标本中HPV16阳性率是77.5%(62/80),而且Shh蛋白的强阳性率在HPV16型阳性的宫颈癌组织中显著高于HPV16阴性组(P<0.05).结论 Hh信号通路蛋白过表达可以作为宫颈癌及其癌前病变的早期辅助诊断指标并有望成为宫颈癌靶向治疗的新靶点,而且Shh蛋白的过表达与HPV16型感染密切相关.     

Expression of Sonic hedgehog pathway genes is altered in colonic neoplasia

The Hedgehog (Hh) signalling pathway is crucial for normal development and patterning of numerous human organs including the gut. Hh proteins are also expressed during gastric gland development and gastric epithelial differentiation in adults. Recently, dysregulation of these developmentally important genes has been implicated in cancer, leading to the present study of the expression of Hh signalling proteins in colon cancer. In this study, normal colon and colonic lesions (hyperplastic polyp, adenoma, and colonic adenocarcinoma) were examined by immunohistochemistry using antibodies against Hh signalling molecules: the secreted protein Sonic hedgehog (SHH), its receptor Patched (PTCH), and the PTCH-associated transmembrane protein Smoothened (SMOH). The study shows that Hh signalling pathway members are expressed in normal colonic epithelium. SHH was expressed at the top of the crypts and in a few basally located cells, while PTCH was detected in the neuroendocrine cells and SMOH at the brush border of superficial epithelium. RT-PCR analysis of laser-microdissected crypts from normal human colon confirmed that mRNAs encoding these proteins were expressed in colonic epithelium. Expression of SHH, PTCH, and SMOH was up-regulated in hyperplastic polyps, adenomas, and adenocarcinomas of the colon, and SHH expression correlated with increased expression of the proliferation marker Ki-67 in all lesions examined. To address whether the Hh signalling pathway is functional in the gut, the effect of Shh on epithelial cells in vitro was explored by treating primary murine colonocytes with either Shh peptide or neutralizing anti-Shh antibody. The proportion of cells in the S-phase was assessed by bromodeoxyuridine (BrdU) incorporation. It was found that exogenous Shh promotes cell proliferation in colonocytes, while anti-Shh inhibits proliferation, suggesting that Shh is required during proliferation of epithelial cells in vitro. It is suggested that SHH is required during epithelial proliferation in the colon and that there is a possible role for Hh signalling in epithelial colon tumour progression in vivo.     

Hedgehog signaling regulates differentiation from double-negative to double-positive thymocyte

The hedgehog (Hh) signaling pathway is involved in the development of many tissues. Here we show that sonic hedgehog (Shh) is involved in thymocyte development. Our data suggest that termination of Hh signaling is necessary for differentiation from CD4-CD8-double-negative (DN) to CD4+CD8+ double-positive (DP) thymocyte. Shh is produced by the thymic stroma, and Patched and Smoothened (Smo), the transmembrane receptors for Shh, are expressed in DN thymocytes. A neutralizing monoclonal antibody against Shh increases differentiation of DN to DP thymocytes, and Shh protein arrests thymocyte differentiation at the CD25+ DN stage, after T cell receptor beta (TCRbeta) gene rearrangement. We show that one consequence of pre-TCR signaling is downregulation of Smo, allowing DN thymocytes to proliferate and differentiate.     

Enhanced expression of hedgehog signaling molecules in squamous cell carcinoma of uterine cervix and its precursor lesions.

The hedgehog (Hh)-signaling pathway plays an essential role in normal development. Deregulation of this pathway is responsible for several types of cancers. The aim of this study was to determine the expression pattern and the extent of Hh-signaling molecules in squamous cell carcinoma of uterine cervix and its precursor lesions. A total of 106 uterine cervical cancers and related lesions (37 squamous cell carcinomas, 23 cervical intraepithelial neoplasia (CIN) III, 10 CIN II, four CIN I, 32 normal cervical epithelia) were immunohistochemically analyzed with anti-Shh, Indian Hh (Ihh), Patched (PTCH), Smoothened (Smo), Gli-1, Gli-2, Gli-3 antibodies on paraffin blocks. The results showed that the expression of all the Hh-signaling molecules was greatly enhanced in uterine cervical tumors, including carcinoma and its precursor lesions. The staining pattern was mainly cytoplasmic except for Gli-1/2, whose expression was observed in both cytoplasm and nucleus. In case of Ihh, PTCH, Smo and Gli-1, their expression in normal epithelium was completely absent or rare. The expression of all the seven Hh-signaling molecules mentioned above was significantly increased in CIN II/III and carcinoma, compared with that in normal epithelium (P < 0.05). The expression of Shh was increased by double; the first increase occurred in normal epithelium-CIN transition, and the second, during the progression of CIN to carcinoma. These results strongly suggest that the Hh-signaling pathways were extensively activated in carcinoma and CIN of uterine cervix. In conclusion, the Hh-signaling pathways may be involved in carcinogenesis of squamous cell carcinoma of uterine cervix and can be considered as a potential therapeutic target.