Sonic Hedgehog信号通路在眼科的应用进展

Sonic Hedgehog（Shh）信号通路与动物胚胎发育及细胞增殖分化密切相关。我们主要综述Shh信号通路在眼球的发育、眼球多种组织细胞的再生和修复、眼科多种疾病发生、发展及治疗的研究及应用。     

Hedgehog signalling in vascular development

The Hedgehog family of proteins are powerful morphogens mediating embryonic development as well as adult morphogenesis and carcinogenesis. For example, excess hedgehog activity has been implicated in basal cell carcinoma, medulloblastoma and rhabdomyosarcoma. More recently, hedgehog signalling has been implicated in angiogenesis. While hedgehog signalling in adult angiogenesis may constitute a simple recapitulation of that in embryonic development, it should be appreciated that Hedgehog signalling occurs in embryonic angiogenesis in different developmental contexts. This article reviews the role of Hedgehog signalling in both embryonic and postnatal vascular development. The temporal importance of a window of hedgehog dependent angiogenesis during development is emphasised and illustrated using a whole mouse embryo culture system.     

Hedgehog signaling displays a biphasic expression pattern during intestinal injury and repair

Background/Purpose

Gastrointestinal injury is common clinically. The exact mechanism by which gastrointestinal repair occurs has yet to be well defined. Hedgehog (Hh) signaling is known to be involved in gastrointestinal development and repair of tissues such as skin and heart. The present study aimed to investigate the role of Hh in the repair of the small intestine.

Methods

i) To study acute intestinal injury, we optimized a mouse model of 5-flurouracil (5-FU) induced injury of the small intestine. Ileal tissues were evaluated for injury and repair markers at day 0, 2, 5, and 9. ii) Immunohistochemistry (Sonic hedgehog, Shh), in situ hybridization (Shh), and Ptch/LacZ transgenic mice were carried out to localize hedgehog expression. A33CrPr × ShhTg knock-in mice were bred to study the effect of Shh over-expression. qPCR of Shh, Ihh, Ptch, Bmp4 was carried out to quantify hedgehog signaling. iii) 5FU treated mice were then treated with a hedgehog inhibitor or saline (control) and the effects of Shh inhibition including apoptosis, proliferation, and mitosis were then compared.

Results

i) Immunohistochemistry and in situ hybridization of Shh, qPCR of hedgehog signaling pathway genes, and Ptch/LacZ staining results consistently showed down-regulation during the injury phase (P < 0.05) followed by up-regulation during the repair phase (P < 0.005). ii) Hh signaling inhibition following 5-FU induced injury augmented apoptotic activity (P < 0.05), suppressed mitotic activity (P < 0.005) in intestinal crypts, and reduced Paneth cell hyperplasia (P < 0.005). iii) Shh over-expression in conditionally knock-mice led to increased mitotic, Paneth, and goblet cells.

Conclusion

Hedgehog signaling pathway displays a biphasic expression pattern during the injury/repair of small intestine. It may play an important regulatory role in intestinal repair.     

核转录因子Gli在肝纤维化发病机制中的作用

核转录因子Gli是Hedgehog（简称Hh）信号通路的核转录因子,Hh信号通路激活最终引起通路末端Gli激活,进入细胞核启动与肝星状细胞（hepatic stellate cell,HSC）活化相关基因,从而促进肝纤维化进程。因此,阐明肝星状细胞和肝纤维化的关系,明确Gli在Hh通路中活化HSC的机制,对于指导肝纤维化的治疗具有重要的理论和现实意义。     

低密度脂蛋白受体抑制剂对低密度脂蛋白和脂蛋白(a)代谢的影响

应用低密度脂蛋白受体抑制剂乳酸肝褐质和受体结合蛋白经刺猬腋下静脉注入，２ｍｉｎ后注射１２５Ⅰ－低密度脂蛋白或１２５Ⅰ－脂蛋白（３），６ｈ后处死，测定血、肝、肾、脾、胆汁和肾上腺的放射活性。实验发现：乳酸肝褐质和受体结合蛋白均能抑制低密度脂蛋白受体活性，使各组织摄取低密度脂蛋白分别降低１５％～８６％以上，但乳酸肝褐质和全体结合蛋白对脂蛋白（ａ）的组织摄取不但无抑制作用，反而能使脂蛋白（ａ）进入组织量增加，激活率分别达４０％～１２６％。实验结果说明：脂蛋白（ａ）虽然与低密度脂蛋白结构相似，含有７０％载脂蛋白Ｂ１００，但由于与载脂蛋白（ａ）以二硫键的形式连接，改变了空间结构，失去了与低密度脂蛋白受体结合的能力，并且推测乳酸肝褐质和受体结合蛋白在抑制低密度脂蛋白受体的同时，可能激活了细胞膜的其它机制，从而利于脂蛋白（ａ）进入细胞内。     

中国人群Hedgehog通路基因与非综合征型唇腭裂的亲源效应

目的:探索非综合征型唇腭裂(non-syndromic cleft lip with or without cleft palate,NSCL/P)这一类常见出生缺陷的可能致病机制,在Hedgehog(HH)通路基因中(PTCH1、PTCH2、SHH、SMO)探索基因多态性对NSCL/P的关联关系以及亲源效应(parent-of-origin effects,PoO)对NSCL/P发病风险的影响。方法:纳入806个中国非综合征型唇腭裂核心家系,对HH通路基因(PTCH1、PTCH2、SHH、SMO)的83个单核苷酸多态性位点(single nucleotide polymorphisms,SNPs)进行传递不平衡检验(transmission disequilibrium test,TDT), 并采用对数线性模型进行亲源效应分析。家系样本来自“唇腭裂基因和交互作用的国际合作研究”项目。采用Plink进行TDT检验;通过R软件中的Haplin v6.2.1软件包开展亲源效应分析。采用Bonferroni法进行多重检验校正。结果:经过质量控制,共纳入65个SNPs进行分析,Bonferroni显著性水平为7.7×10 ^-4(0.05/65)。未校正P值前,关联分析发现rs4448343与NSCL/P存在关联(P=0.023), 6个单体型(rs10512249-rs4448343、rs1461208-rs7786445、rs10512249-rs4448343、rs16909865-rs10512249-rs4448343、rs1461208-rs7786445-rs12698335、rs288756-rs288758-rs1151790)与NSCL/P存在关联(P<0.05);6个单体型(rs288765-rs1233563、rs12537550-rs11765352、rs872723-rs288765-rs1233563、rs288765-rs1233563-rs288756、rs6459952-rs12537550-rs11765352、rs12537550-rs11765352-rs6971211)具有潜在的PoO效应(P<0.05)。以上结果经过多重检验校正,均无统计学意义(P>7.7×10 ^-4)。结论:未发现HH通路基因多态性与NSCL/P的关联,未发现HH通路基因通过PoO效应影响NSCL/P发病风险。     

Hedgehog’s escape from Pandora’s box

 The Hedgehog family of secreted glycoproteins proteins plays multifarious roles during vertebrate embryogenesis. In both the Drosophila and vertebrate embryo correct deployment of Hedgehog-like proteins is critical for the generation of pattern in many tissues and organs. New evidence now reveals that genes involved in hedgehog signalling are mutated in a number of common human genetic disorders, including skin cancer and craniofacial defects. The understanding of how cells generate, receive and transduce the Hedgehog signal during development has led to the establishment of molecular paradigms for the pathogenesis of these diseases. These studies clearly illustrate that knowledge of the normal role of a gene during development is critical for generating an understanding of the disease state in which it is mutated. Received: 22 May 1997 / Accepted: 21 July 1997     

Cortical and brain stem projections to the spinal cord of the hedgehog (Erinaceus europaeus). A horseradish peroxidase study

Summary Cortical and brain stem neurons projecting to the spinal cord in the hedgehog were studied by means of the horseradish peroxidase (HRP) tracing method. HRP injections were placed in the first cervical segments, in the cervical enlargement (C₅-T₃) and in the lumbar enlargement. Following injections in the first cervical segments and in the cervical enlargement labelled neurons were observed in the somatic motor and somatic sensory cortices, the paraventricular and the dorsomedial hypothalamic nucleus, the lateral hypothalamic area, the nuclei of field H of Forel, the red nucleus, the mesencephalic reticular formation, the deep layers of the superior colliculus, the Edinger-Westphal nucleus, the periaqueductal grey, the mesencephalic trigeminal nucleus, the loci coeruleus and subcoeruleus, the nuclei raphe dorsalis, centralis superior, raphe magnus, raphe pallidus, and raphe obscurus, the rhombencephalic reticular formation, the lateral, medial and caudal vestibular nuclei, the nucleus ambiguus, the nucleus of the solitary tract and the gracile nucleus. After HRP injections in the lumbar enlargement, labelled neurons were not found in the cortex, the dorsomedial hypothalamic nucleus, the nuclei of field H of Forel, the superior colliculus and the mesencephalic trigeminal nucleus. These results show that cortical and brain stem projection to the spinal cord are comparable to those described in other species.Abbreviations ac anterior commissure - Am nucleus ambiguus - Aq cerebral aqueduct - cc corpus callosum - Cd caudate nucleus - CE cervical enlargement - CeS nucleus centralis superior - CG periaqueductal grey - ci capsula interna - Cq cochlear nuclei - cp cerebral peduncle - Cu cuneiform nucleus - CV caudal vestibular nucleus - DM dorsomedial hypothalamic nucleus - DX dorsal motor nucleus of vagus - EC external cuneate nucleus - EW Edinger-Westphal nucleus - F nuclei of field H of Forel - G gracile nucleus - H nippocampus - IC inferior colliculus - IP interpeduncular nucleus - LC locus coeruleus - LE lumbar enlargement - LH lateral hypothalamic area - LL nucleus of lateral lemniscus - lo lateral olfactory tract - LV lateral vestibular nucleus - MC medial cuneate nucleus - MesV mesencephalic trigeminal nucleus - MG medial geniculate nucleus - MM medial mammillary nucleus - MV medial vestibular nucleus - oc optic chiasm - PH nucleus praepositus - Pn pontine nuclei - Put putamen - PV paraventricular hypothalamic nucleus - R red nucleus - Rd nucleus raphe dorsalis - RGc gigantocellular reticular nucleus - Rl lateral reticular nucleus - Rm nucleus raphe magnus - Rmes mesencephalic reticular formation - Ro nucleus raphe obscurus - Rpa nucleus raphe pallidus - Rpc caudal reticular nucleus of the pons - Rpo rostral reticular nucleus of the pons - Rv ventral reticular nucleus - s solitary tract - SC superior colliculus - SN substantia nigra - SO supraoptic nucleus - SR sulcus rhinalis - STh subthalamic nucleus - siV spinal tract of trigeminal nerve - STV nucleus of spinal tract of trigeminal nerve - subC locus subcoeruleus - SuM supramammillary nucleus - Th thalamus - TS nucleus of solitary tract - VM ventromedial hypothalamic nucleus - ZI zona incerta - 3V third ventricle - 4V fourth ventricle - IV layer IV of the cortex - V layer V of the cortex - VI layer VI of the cortex - 7 facial nucleus - 12 hypoglossal nucleus     

Treatment of Eyelid Epithelial Neoplasm by Targeting Sonic Hedgehog Signaling: An Experimental Study

Purpose

To evaluate the effect of cyclopamine, an inhibitor of the Sonic hedgehog (Shh) signal, on the growth of an epithelial neoplasm.

Methods

Chemically induced eyelid tumors in XPC-null mice (n = 40) were treated daily with a subcutaneous injection of cyclopamine (1?mg/animal) for 7 days. The animals were killed after bromodeoxyuridine (BrdU) labeling, and the tumors were histologically examined. An in vitro study was conducted by using a squamous cell carcinoma (SCC) cell line. The SCC cells were treated with 0, 12.5, or 25.0?μg/ml recombinant Shh (rShh) and either 0 or 100?μM cyclopamine, and cell proliferation was evaluated by using an MTT assay. Cells from this cell line were also implanted subcutaneously in nude mice (n = 8) to develop tumors, and the effect of cyclopamine administration was examined in the developed tumors.

Results

Histology showed that cyclopamine treatment suppressed BrdU incorporation and induced apoptosis in the majority of cells in tumors chemically induced in the eyelid of the XPC-null mice. Cell proliferation of the SCC cell line was enhanced by adding rShh, and this effect was abolished by adding cyclopamine. Proliferation of the SCC cell line was not affected by adding cyclopamine in the absence of rShh. On the other hand, the SCC cells expressed Shh in vivo in tumors developed in nude mice, but cyclopamine suppressed cell proliferation in the tumors, and the Shh-signaling pathway was inhibited by cyclopamine-induced apoptosis.

Conclusions

Cyclopamine inhibits proliferation and induces apoptosis in epithelial tumor cells in vivo. The Shh-signaling pathway may be a potential therapeutic target for patients with eyelid tumors.?Jpn J Ophthalmol 2006;50:305–311 © Japanese Ophthalmological Society 2006     

Sonic Hedgehog信号通路在胎肺发育和肺部疾病中的研究进展

Sonic Hedgehog(SHH)信号通路不仅在胚胎期发育起重要作用,而且在生后保持组织或器官的完整和功能发育中起重要作用.近年来在肺部疾病中发现SHH信号通路异常激活,提示SHH信号通路可能在肺部疾病中起一定作用.