Neogenin-loss in neural crest cells results in persistent hyperplastic primary vitreous formation

Neogenin is a transmembrane receptor critical for multiple cellular processes,including neurogenesis,astrogliogenesis,endochondral bone formation,and iron homeostasis.Here we present evidence that loss of neogenin contributes to pathogenesis of persistent hyperplastic primary vitreous(PHPV)formation,a genetic disorder accounting for^5% of blindness in the USA.Selective loss of neogenin in neural crest cells(as observed in Wntl-Cre;Neofff mice),but not neural stem cells(as observed in GFAP-Cre and Nestin-Cre;Neo^f/f mice),resulted in a dysregulation of neural crest cell migration or delamination,exhibiting features of PHPV-like pathology(e.g.elevated retrolental mass),unclosed retinal fissure,and microphthalmia.These results demonstrate an unrecognized function of neogenin in preventing PHPV pathogenesis,implicating neogenin regulation of neural crest cell delamination/migration and retinal fissure formation as potential underlying mechanisms of PHPV.

Tbx1 regulates the development of zebrafish neural crest cells by retinoic acid signaling

The TBX1 gene is considered to be the most important gene in the aetiology of DiGeorge syndrome （DGS）.DGS is a human disorder characterised by a number of phenotypic features involving abnormal development of pharyngeal arches, facial dysmorphogenesis and cardiac outflow tract anomalies. Retinoic acid （RA） deficiency also produces DGS-like phenotypes. The affectd tissues in DGS are derivatives of neural crest cells （NCCs）, which originate from the border between the neural plate and non-neural ectoderm, migrate to specific destinations in the body, and generate a variety of derivatives. In our study, we have explored the hypothesis that tbxl affects NCC development in zebrafish by regulating RA signaling.

Follicle and melanocyte stem cells, and their application in neuroscience A Web of Science-based literature analysis

OBJECTIVE： To identify global research trends of follicle and melanocyte stem cells, and their application in neuroscience. DATA RETRIEVAL： We performed a bibliometric analysis of studies from 2002 to 2011 on follicle and melanocyte stem cells, and their application in neuroscience, which were retrieved from the Web of Science, using the key words follicle stem cell or melanocyte stem cell, and neural, neuro or nerve. SELECTION CRITERIA： Inclusion criteria： （a） peer-reviewed published articles on follicle and melanocyte stem cells, and their application in neuroscience, which were indexed in the Web of Science; （b） original research articles, reviews, meeting abstracts, proceedings papers, book chapters, editorial material, and news items. Exclusion criteria： （a） articles that required manual searching or telephone access; （b） documents that were not published in the public domain; and （c） a number of corrected papers from the total number of articles. MAIN OUTCOME MEASURES： （1） Distribution of publications on follicle and melanocyte stem cells by years, journals, countries, institutions, institutions in China, and most cited papers. （2） Distribution of publications on the application of follicle and melanocyte stem cells in neuroscience by years, journals, countries, institutions, and most cited papers. RESULTS： Of the 348 publications from 2002 to 2011 on follicle and melanocyte stem cells, which were retrieved from the Web of Science, more than half were from American authors and institutes. The most prolific institutions in China for publication of papers on follicle and melanocyte stem cells were the Fourth Military Medical University and Third Military Medical University. The most prolific journals for publication of papers on follicle and melanocyte stem cells were the Journal of Investigative Dermatology, Pigment Cell ＆ Melanoma Research. Of the 63 publications from 2002 to 2011 on the application of follicle and melanocyte stem cells in neuroscience, which were retrieved from the Web of Science, more than half were from American authors and institutes, and no papers were from Chinese authors and institutes. The most prolific journals for publication of papers on the application of follicle and melanocyte stem cells in neuroscience were the Journal of Investigative Dermatology, Pigment Cell ＆ Melanoma Research. CONCLUSION： Based on our analysis of the literature and research trends, we found that follicle stem cells might offer further benefits in neural regenerative medicine.

Intradural osteomas:Report of two cases

BACKGROUND Intradural osteoma is very rarely located in the subdural or subarachnoid space.Unfortunately,intradural osteoma lacks specificity in clinical manifestations and imaging features and there is currently no consensus on its diagnosis method or treatment strategy.Moreover,the pathogenesis of osteoma without skull structure involvement remains unclear.CASE SUMMARY We describe two cases of intradural osteomas located in the subdural and subarachnoid spaces,respectively.The first case involved a 47-year-old woman who presented with a 3-year history of intermittent headache and dizziness.Intraoperatively,a bony hard mass was found in the left frontal area,attached to the inner surface of the dura mater and compressing the underlying arachnoid membrane and brain.The second case involved a 56-year-old woman who had an intracranial high-density lesion isolated under the right greater wing of the sphenoid.Intraoperatively,an arachnoid-covered bony tumor was found in the sylvian fissure.The pathological diagnosis for both patients was osteoma.CONCLUSION Surgery and pathological examination are required for diagnosis of intradural osteomas,and craniotomy is a safe and effective treatment.

Effect of Tbxl knock-down on cardiac performance in zebrafish

Background Tbxl is the major candidate gene for DiGeorge syndrome （DGS）. Similar to defects observed in DGS patients, the structures disrupted in Tbxl-/- animal models are derived from the neural crest cells during development. Although the morphological phenotypes of some Tbxl knock-down animal models have been well described, analysis of the cardiac performance is limited. Therefore, myocardial performance was explored in Tbxl morpholino injected zebrafish embryos. Methods To elucidate these issues, Tbxl specific morpholino was used to reduce the function of Tbxl in zebrafish. The differentiation of the myocardial cells was observed using whole mount in situ hybridization. Heart rates were observed and recorded under the microscope from 24 to 72 hours post fertilization （hpf）. The cardiac performance was analyzed by measuring ventricular shortening fraction and atrial shortening fraction.Results Tbxl morpholino injected embryos were characterized by defects in the pharyngeal arches, otic vesicle, aortic arches and thymus. In addition, Tbxl knock down reduced the amount of pharyngeal neural crest cells in zebrafish. Abnormal cardiac morphology was visible in nearly 20% of the Tbxl morpholino injected embryos. The hearts in these embryos did not loop or loop incompletely. Importantly, cardiac performance and heart rate were reduced in Tbxl morpholino injected embryos.Conclusions Tbxl might play an essential role in the development of pharyngeal neural crest cells in zebrafish. Cardiac performance is impaired by Tbxl knock down in zebrafish.

Retinol dehydrogenase, RDHll, is essential for the heart development and cardiac performance in zebrafish

Background Retinoic acid （RA） is a potent signaling molecule that plays pleiotropic roles in patterning, morphogenesis, and organogenesis during embryonic development. The synthesis from retinol （vitamin A） to retinoic acid requires two sequential oxidative steps. The first step involves the oxidation of retinol to retinal through the action of retinol dehydrogenases. Retinol dehydrogenasesll （RDHll） is a novel zebrafish retinol dehydrogenase. Herein we investigated the role of zebrafish RDHll in heart development and cardiac performance in detail. Methods RDHll specific morpholino was used to reduce the function of RDHll in zebrafish. The gene expressions were observed by using whole mount in situ hybridization. Heart rates were observed and recorded under the microscope from 24 to 72 hours post fertilization （hpf）. The cardiac performance was analyzed by measuring ventricular shortening fraction （VSF）. Results The knock-down of RDHll led to abnormal neural crest cells migration and reduced numbers of neural crest cells in RDHll morphant embryos. The reduced numbers of cardiac neural crest cells also can be seen in RDHll morphant embryos. Furthermore, the morpholino-mediated knock-down of RDHll resulted in the abnormal heart loop. The left-right determining genes expression pattern was altered in RDHll morphant embryos. The impaired cardiac performance was observed in RDHll morphant embryos. Taken together, these data demonstrate that RDHll is essential for the heart development and cardiac performance in zebrafish. Conclusions RDHll plays a important role in the neural crest cells development, and then ultimately affects the heart loop and cardiac performance. These results show for the first time that an enzyme involved in the retinol to retinaldehyde conversion participate in the heart development and cardiac performance in zebrafish.