Research progress on the regulation of craniofacial development and malformation by fibroblast growth factor 8 / 口腔疾病防治

@#Fibroblast growth factor 8 (FGF8) is a kind of secretory polypeptide that has crucial roles in the development of various tissues and organs. Current studies have found that FGF8 can regulate the differentiation of cranial neural crest cells by activating the mitogen-activated protein kinase (MAPK) signaling pathway and affect the establishment of mandibular arch polarity and the development of craniofacial symmetry by regulating the expression of target genes. Cleft lip with or without cleft palate, ciliopathies, macrostomia and agnathia are four developmental malformations involving the craniofacial region that seriously affect the quality of life of patients. The abnormal FGF8 signal caused by gene mutation, abnormal protein conformation or expression is closely related to the occurrence of craniofacial malformations, but the molecular mechanism and signaling pathway underlying these malformations have not been fully elucidated. Craniofacial development is a complex process mediated by a variety of signaling molecules. In the future, the role of various signaling molecules in craniofacial development and malformations need to be explored to provide a new perspective and vision for the prevention and treatment of these craniofacial malformations.

TMEM106B Induces Melanogenesis by Regulating ERK/CREB Signaling Pathway / 中国生物化学与分子生物学报

The TMEM106B protein is a type-II transmembrane protein, which localizes in the endosome and lysosome of dendrites in primary neurons. TMEM106B is essential for maintaining and branching of dendrites, and thus regulates retrograde lysosomal trafficking of dendrites in primary neurons. Mammalian melanocytes are derived from neural cells, while melanosomes are originated from early endosome. However, the function of TMEM106B protein in melanocytes and its potential molecular mechanism in melanogenesis still remain unknown. Recently it was reported that transcription factor EB (TFEB) was the regulator of lysosome synthesis and TMEM106B protein overexpression promoted TFEB translocation into the nucleus. However, MITF (microphthalmia-associated transcription factor) and TFEB regulate each other in melanoma cells in vitro. Here in, plasmid containing gene for TMEM106B overexpression was transfected into melanocytes to investigate the regulation of TMEM106B on melanogenesis. The results showed that TMEM106B protein was localized in the cytoplasm of melanocytes. Compared with the negative control (NC), the mRNA levels of cyclic AMP-responsive element-binding protein (CREB) and MITF, especially CREB, were significantly increased in melanocytes with TMEM106B overexpression P< 0. 001). Western blot analysis showed that the expression of phosphorylated MAP kinase (p-ERK) was apparently increased (P<0.001) and resulted in the up-regulation of melanogenic regulatory proteins, including MITF, tyrosinase (TYR), tyrosinase-related protein-1 (TYRP1) and 2 (TYRP2). Masson-Fontana method showed that TMEM106B influenced the production of melanin in melanocytes. The spectrophotometry assay indicated that the amount of total melanin (ASM) (P<0. 001) and eumelanin (EM) (P<0. 05) were increased in alpaca melanocytes transfected with TMEM106B, while pheomelanin (PM) (P<0. 001) was decreased. These results demonstrated that TMEM106B played a vital role in melanogenesis in melanocytes by regulating ERK/CREB signaling pathway.

Pathogenic genes and clinical therapeutic strategies for Treacher Collins syndrome / 华西口腔医学杂志

Treacher Collins syndrome is a congenital craniofacial malformation with autosomal dominant inheritance as the main genetic pattern. In this condition, the biosynthesis of ribosomes in neural crest cells and neuroepithelial cells is blocked and the number of neural crest cells that migrate to the craniofacial region decreases, causing first and second branchial arch dysplasia. Definite causative genes include treacle ribosome biogenesis factor 1 (tcof1), RNA polymerase Ⅰ and Ⅲ subunit C (polr1c), and RNA polymerase Ⅰ and Ⅲ subunit D (polr1d). This paper provides a review of research of three major patho-genic genes, pathogenesis, phenotypic research, prevention, and treatment of the syndrome.

The expressions of ALX family genes in human neural crest cells and their derived cells / 中华整形外科杂志

Objective@#To compare the expressions of ALX gene family members (ALX1, ALX3, ALX4) in human embryonic stem cells (hESCs) and their differentiated neural crest cells (NCCs), as well as human mesenchymal stem cells (MSCs) and peripheral neurons derived from NCCs. The result provided a research foundation for understanding the expressions of ALX gene family in the process of NCCs differentiation.@*Methods@#The characteristics of hESCs, NCCs, MSCs and peripheral neurons were identified by RT-PCR, immunofluorescence staining and flow cytometry analysis. The expressions of ALX1, ALX3 and ALX4 were quantified by Real-time PCR.@*Results@#The expressions of ALX1 were significantly lower in MSCs than in NCCs (P < 0.05). However, the expression of ALX3 was significantly higher in MSCs than in hESCs, NCCs, peripheral neurons and osteoblasts (P < 0.05). The expressions of ALX4 were higher in MSCs, peripheral neurons and osteoblasts.@*Conclusions@#The expression profiles of different ALX genes in stem cells at different development stages are different, suggesting the regulation of ALX genes expressions is different in diverse cells.

Células de la cresta neural y su relación con cardiopatía congénita: revisión sistemática de la literatura / Neural crest cells and their relation to congenital heart disease: systematic review of the literature

Las cardiopatías congénitas corresponden al grupo de anomalías del desarrollo que se presentan con mayor frecuencia. Durante el desarrollo cardíaco participan distintos linajes celulares, donde destacan las Células de la Cresta Neural (CCN) por su amplia gama de derivados embriológicos y la susceptibilidad de afectar a múltiples sistemas si su función es alterada. El objetivo fue determinar el rol que cumplen las CCN durante el desarrollo cardíaco y las cardiopatías congénitas asociadas. Se diseñó un estudio descriptivo en base a una revisión sistemática de la literatura de las bases de datos MEDLINE y Scopus, utilizando la combinación de términos MeSH: ("Heart Diseases/congenital" OR "Heart Diseases/embriology" OR "Heart Diseases/etiology" OR "Heart Disesaes/epidemiology") AND ("Neural Crest/abnormalities"). Se restringió la búsqueda a artículos de los últimos 10 años. De un total de 35 artículos obtenidos, 22 fueron incluidos para su revisión por estar relacionados con los objetivos de este estudio, excluyéndose duplicados entre bases de datos. Posteriormente se hizo un análisis individual y en conjunto de la información obtenida de los artículos seleccionados. La evidencia indica la participación directa o indirecta de las CCN durante la formación de las estructuras derivadas del polo arterioso del corazón en desarrollo, los grandes vasos arteriales y sus ramas colaterales, así como en su inervación y sistema de conducción. La alteración del funcionamiento normal de las CCN produce fenotipos cardíacos alterados, siendo la persistencia del tronco arterioso, doble salida ventricular derecha, defectos septales interventriculares y malformación de los aparatos valvares aórtico y pulmonar, los más frecuentes.

Congenital heart defects are the group of most frequent anomalies of development. Cardiac development in different cell lines, which include the Neural crest cells (NCC) for their wide range of embryological derivatives and susceptibility to affect multiple systems if their function is altered participate. The objective was to determine the role of the NCC during heart development and associated congenital heart disease. A descriptive study was designed based on a systematic review of the literature from the MEDLINE and Scopus data, using a combination of MeSH terms ("Heart Diseases / congenital" OR "Heart Diseases / Embryology" OR "Heart Diseases/etiology "OR" Heart Diseases/epidemiology ") AND ("Neural Crest/abnormalities"). Search for articles in the last 10 years was restricted. From a total of 35 articles retrieved, 22 were included related to the objectives of this study for review, excluding duplicated between databases. Subsequently, an individual and joint analysis was realized with the information from the selected items. Evidence indicates the direct or indirect involvement of NCC during the formation of the structures derived from arterial pole of the developing heart, the large arterial vessels and their collateral branches, as well as its innervation and conduction system. The disruption of normal operation of the NCC produces altered cardiac phenotypes, with the Persistence Truncus Arteriosus, Double-Outlet Right Ventricle, ventricular Septal Defects and malformation of the most common valvular aortic and pulmonary devices.

Coronary Anomalies: Understanding of Normal Coronary Artery Development for Insight in Treatment of Coronary Artery Disease.

Coronary artery anomalies (CAA) are rare congenital abnormalities with incidence of about 1% in the general population.2Unfortunately, despite the low incidence, CAA can cause sudden cardiac death. Identifying the course of the artery is critical for appropriate management. We present a rare case of the left coronary artery arising from the right coronary ostium with special emphasis on normal coronary artery development as possible insight for treatment of diseased heart.

Does Dlx abnormal expression regulate the migration of cranial neural crest cells and development of the first brachial arch? / 中国组织工程研究

BACKGROUND: Dlx gene family is highly expressed in the cranial neural crest cells, and regulates the cranial neural crest cel migration and differentiation. OBJECTIVE: To review the mechanism that the highly-expressed Dlx genes mediate the cranial neural crest cel migration and differentiation. METHODS: An online search of CNKI and Medline databases was performed for articles published before 2013 using keywords of “cranial neural crest cells, migration of cranial neural crest cells, Dlx, Dlx overexpression, Fgf, chodrogenesis, osteogenesis” in Chinese and English, respectively. Relevant articles were summarized from three aspects: the migration of cranial neural crest cells, Dlx over-expression’s impact on the migration of cranial neural crest cells, interaction between the environment and Dlx genes. A total of 63 articles were included. According to inclusion criteria, 43 articles were retained at last. RESULTS AND CONCLUSION: Dlx abnormal-expression wil lead to cel -cel adhesion. Dlx over-expression wil induce most of the cranial neural crest cells aggregate and migrate to a wrong place, and result in skeletal dysmorphology. Dlx over-expression wil also lead to ectopic chondrogenesis, and the interaction between cel factors can be the possible reason for this.

Desarrollo de Cara y Cuello en Vertebrados / Face and Neck Development in Vertebrates

El desarrollo embrionario de las regiones facial, del cuello, cavidades nasales y oral en conjunto con las glándulas asociadas, involucra el crecimiento y fusión tridimensional de múltiples procesos. Existe participación de elementos derivados de las 3 capas embrionarias locales y adicionalmente de células derivas de la cresta neural, procedentes de los rombómeros vecinos. Estas últimas se ven involucradas en la formación del esqueleto local, entre otras estructuras. El estudio evolutivo desde los vertebrados sin mandíbula nos enseña como se expresan los genes Hox en las diferentes especies, y como esto determina la formación de diferentes estructuras. En la siguiente revisión contemplamos algunos aspectos morfológicos, moleculares y evolutivos básicos del desarrollo facial y cervical, con énfasis en mamíferos con un epílogo referente a las malformaciones de la región en humanos.

The embryonic development of the facial area, neck, nasal, oral and pharyngeal cavities with glands, involves growth and fusion of multi-dimensional processes. There is involvement of elements from the embryo-derived local 3 layers cells further neural crest derived cells from the neighbors rhombomeres. The neural crest cells are involved in the formation of local skeleton, among other structures. The study of evolution from jawless vertebrates shows us how Hox genes are expressed in different species, and how this determines the formation of different structures. The following review contemplate some morphological, molecular and evolutionary basis of facial and neck development, with emphasis on mammals with an epilogue concerning to the face and neck malformations in humans.

Conditional deletion of the human ortholog gene Dicer1 in Pax2-Cre expression domain impairs orofacial development.

Background: Orofacial clefts are common worldwide and result from insufficient growth and/or fusion during the genesis of the derivatives of the first pharyngeal arch and the frontonasal prominence. Recent studies in mice carrying conditional and tissue-specific deletions of the human ortholog Dicer1, an RNAse III family member, have highlighted its importance in cell survival, differentiation, proliferation, and morphogenesis. Nevertheless, information regarding Dicer1 and its dependent microRNAs (miRNAs) in mammalian palatogenesis and orofacial development is limited. Aims: To describe the craniofacial phenotype, gain insight into potential mechanisms underlying the orofacial defects in the Pax2-Cre/Dicer1 CKO mouse, and shed light on the role of Dicer1 in mammalian palatogenesis. Materials And Methods: Histological and molecular assays of wild type (WT) and Pax2-Cre/Dicer1 loxP/loxP (Dicer1 CKO) mice dissected tissues have been performed to characterize and analyze the orofacial dysmorphism in Pax2-Cre/Dicer1 loxP/loxP mouse. Results: Dicer1 CKO mice exhibit late embryonic lethality and severe craniofacial dysmorphism, including a secondary palatal cleft. Further analysis suggest that Dicer1 deletion neither impacts primary palatal development nor the initial stages of secondary palatal formation. Instead, Dicer1 is implicated in growth, differentiation, mineralization, and survival of cells in the lateral palatal shelves. Histological and molecular analysis demonstrates that secondary palatal development becomes morphologically arrested prior to mineralization around E13.5 with a significant increase in the expression levels of apoptotic markers (P < 0.01). Conclusions: Pax2-Cre-mediated Dicer1 deletion disrupts lateral palatal outgrowth and bone mineralization during palatal shelf development, therefore providing a mammalian model for investigating the role of miRNA-mediated signaling pathways during palatogenesis.

Retinoic acid and mammalian craniofacial morphogenesis.

Retinoic acid is a morphogenetic signalling molecule in vertebrate embryos, one being known to perform a specific function in organizing the body pattern along the anteroposterior axis. This molecule has especially attracted research attention because retinoic acid treatment will also induce abnormal morphogenesis, particularly in the craniofacial structures. The present review discusses recent molecular insights revealing how the retinoic acid signal is transduced within a cell, specifically focusing on the involvement of cranial neural crest cells in retinoic acid-induced abnormal morphogenesis in the mammalian head.