Brain deficits associated with fetal alcohol exposure may be protected, in part, by peptides derived from activity-dependent neurotrophic factor and activity-dependent neuroprotective protein

This review discusses the effects of prenatal alcohol exposure on the developing brain and the potential use of derived peptides from activity-dependent neurotrophic factor (ADNF) and activity-dependent neuroprotective protein (ADNP) in neuroprotection against the insults of alcohol. Alcohol is known to impede the growth of the central nervous system and to induce neurodegeneration through cellular apoptosis. Sari et al. have shown that prenatal alcohol exposure reduced the fetal brain weight, the size of the brain regions and the number of serotonin (5-HT) neurons. Prenatal alcohol exposure compromises neural tube midline development. Sari et al. further suggested that the timing of alcohol exposure during pregnancy is critical to the induction of deficits in 5-HT neurons, as well as other types of neurons and consequently results in deficits in neural tube development. ADNF and ADNP are glial-derived proteins discovered to be induced by vasoactive intestinal peptide (VIP). These proteins are expressed during embryonic development. Functional assays and genetic manipulations have identified these proteins as highly important for neural tube closure and brain formation/development. The peptide derivatives of ADNF, ADNF-14 (VLGGGSALLRSIPA), ADNF-9 (or SALLRSIPA = SAL) and of ADNP, NAPVSIPQ = NAP have shown neuroprotective effects and have been proven to prevent brain damage associated with prenatal alcohol exposure in animals. Here, we discuss the many aspects of alcohol-associated growth restriction in the developing brain and the potential inhibition of this severe phenotype through the use of neuroprotective peptides.     

Shh和bFGF在胰腺癌中的表达及其与临床病理特征关系

[目的]探讨Shh、bFGF在胰腺癌组织中的表达及其意义。[方法]应用免疫组织化学SP法检测Shh和bFGF蛋白在34例手术切除的原发性胰腺癌组织，21例胰腺良性病变组织中的表达。[结果]Shh在胰腺癌组织中阳性表达率为64．7％（22／34），高于胰腺良性病变组织（0／21）（X^2=22．647，P=-0．000）。bFGF在胰腺癌组织和胰腺良性病变中阳性表达率分别为67．6％（23／34）和66．7％（14／21），无显著性差异（X^2=0．006，P=0．940）。Shh表达与患者年龄、性别及肿瘤部位、大小、分化、淋巴结转移、血管浸润无明显相关，与肿瘤TNM分期、远处转移密切相关（P〈0．05）；bFGF的表达与TNM分期、血管浸润、远处转移密切相关（P〈0．05）。胰腺癌组织中Shh表达与bFGF表达呈正相关（r=-0．410，P=0．016）。[结论]Shh和bFGF在胰腺癌组织的表达与胰腺癌的分期和远处转移相关；两者可能在胰腺癌发生发展中起协同作用。     

口腔鳞癌中Shh/Gli1的表达及其临床生物学意义

目的：明确Hedgehog信号通路关键分子Shh及Gli1在口腔鳞癌中的表达情况,并初步探讨其与口腔鳞癌临床生物学的关系及对预后的影响。方法：采用免疫组织化学方法分别检测35例正常口腔黏膜及35例口腔鳞癌中Shh和Gli1的表达及细胞内定位情况。采用SPSS11.0软件包对Shh、Gli1的表达与口腔鳞癌患者的各项临床病理参数进行非参数统计分析,应用生存表法分析Shh及Gli1的表达水平与口腔鳞癌患者预后的关系。结果：Shh及Gli1在35例正常黏膜中均无表达,在口腔鳞癌组织中Shh的阳性率为60%,Gli1胞质、胞核阳性率分别为54.3%及42.9%,与正常黏膜相比差异显著（P〈0.05）。非参数分析显示,Shh的表达水平与口腔鳞癌患者的肿瘤大小及临床分期显著相关（P〈0.05）;生存分析表明,Shh的表达水平与口腔鳞癌患者预后相关,高表达的口腔鳞癌患者预后较差（P〈0.05）。Gli1的表达水平与口腔鳞癌患者预后不相关。结论：Hedgehog信号通路的主要配体Shh及核转录因子Gli1在口腔鳞癌中有不同程度的表达,其中Shh的表达水平与肿瘤大小、临床分期及患者预后明显相关,提示Hedgehog信号通路的异常激活在口腔鳞癌中发挥一定的作用。     

Neural crest cells pattern the surface cephalic ectoderm during FEZ formation

Background: Multiple fibroblast growth factor (Fgf) ligands are expressed in the forebrain and facial ectoderm, and vascular endothelial growth factor (VEGF) is expressed in the facial ectoderm. Both pathways activate the MAP kinase cascade and can be suppressed by SU5402. We placed a bead soaked in SU5402 into the brain after emigration of neural crest cells was complete. Results: Within 24 hr we observed reduced pMEK and pERK staining that persisted for at least 48 hr. This was accompanied by significant apoptosis in the face. By day 15, the upper beaks were truncated. Molecular changes in the FNP were also apparent. Normally, Shh is expressed in the frontonasal ectodermal zone and controls patterned growth of the upper jaw. In treated embryos, Shh expression was reduced. Both the structural and molecular deficits were mitigated after transplantation of FNP‐derived mesenchymal cells. Conclusions: Thus, mesenchymal cells actively participate in signaling interactions of the face, and the absence of neural crest cells in neurocristopathies may not be merely structural. Developmental Dynamics 241:732–740, 2012. © 2012 Wiley Periodicals, Inc.     

Signaling by SHH rescues facial defects following blockade in the brain

Background : The Frontonasal Ectodermal Zone (FEZ) is a signaling center in the face that expresses Sonic hedgehog (Shh) and regulates patterned growth of the upper jaw. Blocking SHH in the forebrain blocks Shh expression in the FEZ and creates malformations resembling holoprosencephaly (HPE), while inhibition of BMP signaling in the mesenchyme blocks FEZ formation and causes similar dysmorphology. Thus, the brain could regulate FEZ formation by SHH or BMP signaling, and if so, activating one of these pathways in the face might alleviate the effects of repression of SHH in the brain. Results : We blocked SHH signaling in the brain while adding SHH or BMP between the neural and facial ectoderm of the frontonasal process. When applied early, SHH restored Shh expression in the FEZ and significantly improved shape outcomes, which contrasts with our previous experiments that showed later SHH treatments have no effect. BMP‐soaked beads introduced early and late caused apoptosis that exacerbated malformations. Finally, removal of Smoothened from neural crest cells did not inhibit Shh expression in the FEZ. Conclusions : Collectively, this work suggests that a direct, time‐sensitive SHH signal from the brain is required for the later induction of Shh in the FEZ. We propose a testable model of FEZ activation and discuss signaling mediators that may regulate these interactions. Developmental Dynamics 241:247–256, 2012. © 2012 Wiley Periodicals, Inc.     

Autonomous and nonautonomous roles of Hedgehog signaling in regulating limb muscle formation

Muscle progenitor cells migrate from the lateral somites into the developing vertebrate limb, where they undergo patterning and differentiation in response to local signals. Sonic hedgehog (Shh) is a secreted molecule made in the posterior limb bud that affects patterning and development of multiple tissues, including skeletal muscles. However, the cell-autonomous and non-cell-autonomous functions of Shh during limb muscle formation have remained unclear. We found that Shh affects the pattern of limb musculature non-cell-autonomously, acting through adjacent nonmuscle mesenchyme. However, Shh plays a cell-autonomous role in maintaining cell survival in the dermomyotome and initiating early activation of the myogenic program in the ventral limb. At later stages, Shh promotes slow muscle differentiation cell-autonomously. In addition, Shh signaling is required cell-autonomously to regulate directional muscle cell migration in the distal limb. We identify neuroepithelial cell transforming gene 1 (Net1) as a downstream target and effector of Shh signaling in that context.     

Influence of retinoic acid on TBX1 expression in myocardial cells induced by Shh and Fgf8

The aim of this study was to explore the regulatory mechanism of retinoic acid (RA) on the TBX1 gene expression in myocardial cells. Ventricular cardiocytes were isolated from neonatal rats and cultured, and then treated with different concentrations of retinoic acid. The expression of Shh and Fgf8 at mRNA and protein levels in neonatal rat myocardial cells were measured by using RT-PCR and Western blot technique, respectively. There was basal expression of Shh and Fgf8 in the control group. When treated with 3×10^-7 mol/L RA, we observed that the expression of Shh mRNA and protein in neonatal rat myocardial cells were up-regulated by 1.51 (P<0.05) and 1.10 times (P<0.05), respectively. In comparison with the control group, under the concentration of 5×10^-7 mol/L RA, they were up-regulated by 2.21 (P<0.05) and 2.38 times (P<0.05) individually. Meanwhile, we could detect that the expression of Fgf8 mRNA and protein were up-regulated by 2.50 times (P<0.05) and 80% (P<0.05) separately compared with the control group after stimulation of 3×10^-7 mol/L RA, and they were up-regulated by 3.48 (P<0.05) and 2.04 times (P<0.05) individually after stimulation of 5×10^-7 mol/L RA. The results indicated that RA could induce the expression of Shh and Fgf8 in neonatal rat myocardial cells. At the same time, it has shown that Shh and Fgf8 were involved in the regulation process of RA on TBX1 expression.     

百会及印堂穴对七氟醚麻醉后大鼠认知功能的影响及机制探究

目的:观察电针百会穴、印堂穴对七氟醚麻醉后大鼠认知功能的影响,同时检测脑组Sonic Hedgehog(Shh)通路标志性蛋白水平的变化。方法:纳入30只SPF级SD大鼠,随机分为空白组、麻醉组及电针组,每组10只。空白组大仅进行模拟捉拿,麻醉组大鼠吸入3.0%七氟醚30 min,随后用1.5%七氟醚麻醉维持3 h,电针组在此基础上进行电针干预,连续干预7 d。干预结束后用Morris水迷宫检测各组学习记忆能力变化,HE染色法观察各组海马组织的结构变化,Western blot及Real-Time PCR法检测各组海马组织Shh、Gli、PI3K、pAKT蛋白及mRNA的水平变化。结果:1)Morris水迷宫显示:麻醉组及电针组大鼠游泳总路程及逃避潜伏期明显较空白组延长(P<0.05),其中电针组较麻醉组明显改善(P<0.05)。2)HE染色提示空白组大鼠海马组织结构形态正常,麻醉组及电针组大鼠海马组织均出现明显结构破坏,细胞排列错乱,神经元细胞出现明显变形缩小,其中电针组海马形态结构较麻醉组改善。3)Western blot及PT-PCR的结果显示,麻醉组及电针组大鼠海马组织Shh、Gli、PI3K、p-AKT蛋白及mRNA表达较空白组降低(P<0.05),其中电针组较麻醉组改善(P<0.05)。结论:七氟醚可对认知能力产生一定损害效应,电针百会穴、印堂穴可明显提升认知能力,其作用机制可能与激活Shh通路通路有关。