Az embrionális GAD formák szerepe a fejlődő szagló-rendszerben = Role of Embryonic GAD Forms in the Developing Olfactory System

Mindkét GAD gén kifejeződik a 10 napos egér embrió szagló plakódjában. Az expresszió a későbbiekben a szaglóhámban marad meg. Két részlegesen átfedő GABAerg sejtpopulációt azonosítottunk a fejlődő frontonazális nyúlványban: ezek a vándorló LHRH+/GAD65+eGAD+ sejtcsoport és az un. "migratory mass" (MM), amely GAD67+(eGAD)/OMP+ sejteket tartalmaz. A GAD65 jelenlétét először sikerült azonosítanunk a vándorló LHRH+ sejtekben. A GAD65 expresszió 1 hónapos korig folytatódik a már nem vándorló LHRH tartalmú idegsejt populációban is. A felnőtt GAD67 gyakorlatilag nem mutatható ki a frontonazális nyúlványban. Ebben a struktúrában a GAD67 génről alternetív "splicing" mechanizmussal képződő embrionális GAD a fő GAD fehérjeforma. A GAD65 hiányos egérben az LHRH neuronok vándorlása a GABAA receptor gátlásához hasonló módon zavart: a vándorlás sebessége fokozódott és iránya az előagyban megváltozott. A GAD67 hiánya nem befolyásolta jelentősen az LHRH+ sejtek vándorlását. Ennek valószínű magyarázata az, hogy a GAD67 KO egerekben az embrionális GAD mennyisége megnövekedett. | 1) Both GAD genes are expressed in the mouse embryo as early as E10 in the olfactory placode. The expression later is maintained in the olfactory epithelium (OE). 2) We have found that, except for the OE, there are two partially overlapping GABAergic lineages in the developing frontonasal process: the migratory LHRH+/GAD65+/eGAD+ and the migratory mass (MM), which is: GAD67+(eGAD)+/OMP+. The identification of GAD65 in the migratory LHRH+ cells is a novel result. 3) GAD65 expression in the LHRH lineage continues in the post-migratory LHRH+ neurons until the first month postnatally. 4) The adult GAD67 is barely expressed in the frontonasal process, instead, the alternatively spliced embryonic GAD is the predominant GAD derived from the GAD67 gene. 5) The absence of GAD65 in GAD65 KO mice impared the migration of LHRH+ cells in a way similar to the effect of GABA- A-R inhibitors, namely, enhanced speed of migration and change in direction of migration in the forebrain part of the migratory route. 6) The absence of GAD67 in GAD67 KO mice is not so pronounced, probably due to up-regulation of embryonic GAD

Interplay of SOX transcription factors and microRNAs in the brain under physiological and pathological conditions

Precise tuning of gene expression, accomplished by regulatory networks of transcription factors, epigenetic modifiers, and microRNAs, is crucial for the proper neural development and function of the brain cells. The SOX transcription factors are involved in regulating diverse cellular processes during embryonic and adult neurogenesis, such as maintaining the cell stemness, cell proliferation, cell fate decisions, and terminal differentiation into neurons and glial cells. MicroRNAs represent a class of small non-coding RNAs that play important roles in the regulation of gene expression. Together with other gene regulatory factors, microRNAs regulate different processes during neurogenesis and orchestrate the spatial and temporal expression important for neurodevelopment. The emerging data point to a complex regulatory network between SOX transcription factors and microRNAs that govern distinct cellular activities in the developing and adult brain. Deregulated SOX/microRNA interplay in signaling pathways that influence the homeostasis and plasticity in the brain has been revealed in various brain pathologies, including neurodegenerative disorders, traumatic brain injury, and cancer. Therapeutic strategies that target SOX/microRNA interplay have emerged in recent years as a promising tool to target neural tissue regeneration and enhance neurorestoration. Numerous studies have confirmed complex interactions between microRNAs and SOX-specific mRNAs regulating key features of glioblastoma. Keeping in mind the crucial roles of SOX genes and microRNAs in neural development, we focus this review on SOX/microRNAs interplay in the brain during development and adulthood in physiological and pathological conditions. Special focus was made on their interplay in brain pathologies to summarize current knowledge and highlight potential future development of molecular therapies

SOX Transcription Factors as Important Regulators of Neuronal and Glial Differentiation During Nervous System Development and Adult Neurogenesis

The SOX proteins belong to the superfamily of transcription factors (TFs) that display properties of both classical TFs and architectural components of chromatin. Since the cloning of the Sox/SOX genes, remarkable progress has been made in illuminating their roles as key players in the regulation of multiple developmental and physiological processes. SOX TFs govern diverse cellular processes during development, such as maintaining the pluripotency of stem cells, cell proliferation, cell fate decisions/germ layer formation as well as terminal cell differentiation into tissues and organs. However, their roles are not limited to development since SOX proteins influence survival, regeneration, cell death and control homeostasis in adult tissues. This review summarized current knowledge of the roles of SOX proteins in control of central nervous system development. Some SOX TFs suspend neural progenitors in proliferative, stem-like state and prevent their differentiation. SOX proteins function as pioneer factors that occupy silenced target genes and keep them in a poised state for activation at subsequent stages of differentiation. At appropriate stage of development, SOX members that maintain stemness are down-regulated in cells that are competent to differentiate, while other SOX members take over their functions and govern the process of differentiation. Distinct SOX members determine down-stream processes of neuronal and glial differentiation. Thus, sequentially acting SOX TFs orchestrate neural lineage development defining neuronal and glial phenotypes. In line with their crucial roles in the nervous system development, deregulation of specific SOX proteins activities is associated with neurodevelopmental disorders (NDDs). The overview of the current knowledge about the link between SOX gene variants and NDDs is presented. We outline the roles of SOX TFs in adult neurogenesis and brain homeostasis and discuss whether impaired adult neurogenesis, detected in neurodegenerative diseases, could be associated with deregulation of SOX proteins activities. We present the current data regarding the interaction between SOX proteins and signaling pathways and microRNAs that play roles in nervous system development. Finally, future research directions that will improve the knowledge about distinct and various roles of SOX TFs in health and diseases are presented and discussed

SOX14 activates the p53 signaling pathway and induces apoptosis in a cervical carcinoma cell line

SOX14 is a member of the SOX family of transcription factors mainly involved in the regulation of neural development. Recently, it became evident that SOX14 is one of four hyper-methylated genes in cervical carcinoma, considered as a tumor suppressor candidate in this type of malignancy. In this paper we elucidated the role of SOX14 in the regulation of malignant properties of cervical carcinoma cells in vitro. Functional analysis performed in HeLa cells revealed that SOX14 overexpression decreased viability and promoted apoptosis through altering the expression of apoptosis related genes. Our results demonstrated that overexpression of SOX14 initiated accumulation of p53, demonstrating potential cross-talk between SOX14 and the p53 signaling pathway. Further analysis unambiguously showed that SOX14 triggered posttranslational modification of p53 protein, as detected by the significantly increased level of phospho-p53 (Ser-15) in SOX14-overexpressing HeLa cells. Moreover, the obtained results revealed that SOX14 activated p53 protein, which was confirmed by elevated p21 Waf1/Cip1, a well known target gene of p53. This study advances our understanding about the role of SOX14 and might explain the molecular mechanism by which this transcription factor could exert tumor suppressor properties in cervical carcinoma

Epigenetic regulation of human SOX3 gene expression during early phases of neural differentiation of NT2/D1 cells

Sox3/SOX3 is one of the earliest neural markers in vertebrates. Together with the Sox1/SOX1 and Sox2/SOX2 genes it is implicated in the regulation of stem cell identity. In the present study, we performed the first analysis of epigenetic mechanisms (DNA methylation and histone marks) involved in the regulation of the human SOX3 gene expression during RA-induced neural differentiation of NT2/D1 cells. We show that the promoter of the human SOX3 gene is extremely hypomethylated both in undifferentiated NT2/D1 cells and during the early phases of RA-induced neural differentiation. By employing chromatin immunopre-cipitation, we analyze several histone modifications across different regions of the SOX3 gene and their dynamics following initiation of differentiation. In the same timeframe we investigate profiles of selected histone marks on the promoters of human SOX1 and SOX2 genes. We demonstrate differences in histone signatures of SOX1, SOX2 and SOX3 genes. Considering the importance of SOXB1 genes in the process of neural differentiation, the present study contributes to a better understanding of epigenetic mechanisms implicated in the regulation of pluripotency maintenance and commitment towards the neural lineage

Current Opportunities for Targeting Dysregulated Neurodevelopmental Signaling Pathways in Glioblastoma

Glioblastoma (GBM) is the most common and highly lethal type of brain tumor, with poor survival despite advances in understanding its complexity. After current standard therapeutic treatment, including tumor resection, radiotherapy and concomitant chemotherapy with temozolomide, the median overall survival of patients with this type of tumor is less than 15 months. Thus, there is an urgent need for new insights into GBM molecular characteristics and progress in targeted therapy in order to improve clinical outcomes. The literature data revealed that a number of different signaling pathways are dysregulated in GBM. In this review, we intended to summarize and discuss current literature data and therapeutic modalities focused on targeting dysregulated signaling pathways in GBM. A better understanding of opportunities for targeting signaling pathways that influences malignant behavior of GBM cells might open the way for the development of novel GBM-targeted therapies

SOX18 Is a Novel Target Gene of Hedgehog Signaling in Cervical Carcinoma Cell Lines

Although there is much evidence showing functional relationship between Hedgehog pathway, in particular Sonic hedgehog, and SOX transcription factors during embryonic development, scarce data are available regarding their crosstalk in cancer cells. SOX18 protein plays an important role in promoting tumor angiogenesis and therefore emerged as a promising potential target in antiangiogenic tumor therapy. Recently it became evident that expression of SOX18 gene in tumors is not restricted to endothelium of accompanying blood and lymphatic vessels, but in tumor cells as well. In this paper we have identified human SOX18 gene as a novel target gene of Hedgehog signaling in cervical carcinoma cell lines. We have presented data showing that expression of SOX18 gene is regulated by GLI1 and GLI2 transcription factors, final effectors of Hedgehog signaling, and that modulation of Hedgehog signaling activity in considerably influence SOX18 expression. We consider important that Hedgehog pathway inhibitors reduced SOX18 expression, thus showing, for the first time, possibility for manipulationwith SOX18 gene expression. In addition, we analyzed the role of SOX18 in malignant potential of cervical carcinoma cell line, and showed that its overexpression has no influence on cells proliferation and viability, but substantially promotes migration and invasion of cells in vitro. Pro-migratory effect of SOX18 suggests its role in promoting malignant spreading, possibly in response to Hedgehog activation

All-trans retinoic acid influences viability, migration and adhesion of U251 glioblastoma cells

Glioblastoma (GBM) is one of the most aggressive and deadly forms of cancer. Literature data reveals that all-trans retinoic acid (ATRA) has anticancer effects on different types of tumor cells. However, data about the effects of ATRA on glioblastoma cells are contradictory. In this study, we examined whether ATRA treatment affects features of human glioblastoma U251 cells. To that end, the cells were treated with different concentrations of ATRA. Results obtained by MTT and the crystal violet assays imply that ATRA affected the viability of U251 glioblastoma cells in a dose-and time-dependent manner. Fluorescence staining of microtubule cytoskeleton protein a-tubulin revealed that ATRA induced changes in cell morphology. Using semi-quantitative RT-PCR we found that the expression of SOX3 and GFAP genes, as markers of neural differentiation, was not changed upon ATRA treatment. Thus, the observed changes in cell morphology after ATRA treatment are not associated with neural differentiation of U251 glioblastoma cells. The scratch-wound healing assay revealed that ATRA changed the mode of U251 cell migration from collective to single cell motility. The cell-matrix adhesion assay demonstrated that the pharmacologically relevant concentration of ATRA lowered the cell-matrix adhesion capability of U251 cells. In conclusion, our results imply that further studies are needed before ATRA could be considered for the treatment of glioblastoma

Expression Analysis of SOX14 during Retinoic Acid Induced Neural Differentiation of Embryonal Carcinoma Cells and Assessment of the Effect of Its Ectopic Expression on SOXB Members in HeLa Cells

SOX14 is a member of the SOXB2 subgroup of transcription factors implicated in neural development. Although the first SOX14 gene in vertebrates was cloned and characterized more than a decade ago and its expression profile during development was revealed in various animal model systems, the role of this gene during neural development is largely unknown. In the present study we analyzed the expression of SOX14 in human NT2/D1 and mouse P19 pluripotent embryonal carcinoma cells. We demonstrated that it is expressed in both cell lines and upregulated during retinoic acid induced neural differentiation. We showed that SOX14 was expressed in both neuronal and non-neuronal differentiated derivatives, as revealed by immunocytochemistry. Since it was previously proposed that increased SOXB2 proteins level interfere with the activity of SOXB1 counteracting partners, we compared expression patterns of SOXB members during retinoic acid induction of embryonal carcinoma cells. We revealed that upregulation of SOX14 expression is accompanied by alterations in the expression patterns of SOXB1 members. In order to analyze the potential cross-talk between them, we generated SOX14 expression construct. The ectopic expression of SOX14 was demonstrated at the mRNA level in NT2/D1, P19 and HeLa cells, while an increased level of SOX14 protein was detected in HeLa cells only. By transient transfection experiments in HeLa cells we showed for the first time that ectopic expression of SOX14 repressed SOX1 expression, whereas no significant effect on SOX2, SOX3 and SOX21 was observed. Data presented here provide an insight into SOX14 expression during in vitro neural differentiation of embryonal carcinoma cells and demonstrate the effect of its ectopic expression on protein levels of SOXB members in HeLa cells. Obtained results contribute to better understanding the role of one of the most conserved SOX proteins

Extract of Herba Anthrisci cerefolii: Chemical Profiling and Insights into Its Anti-Glioblastoma and Antimicrobial Mechanism of Actions

Anthriscus cerefolium (L.) Hoffm. is a plant traditionally used around the globe since antiquity. Although widely used in many traditional medicines in different cultures, from the scientific point of view it is poorly investigated. Glioblastoma, a tumor type with poor prognosis, is the most common and lethal brain tumor in adults. Current therapeutic strategies for glioblastoma include surgery, radiation and chemotherapy. On the other hand, it has been revealed that patients with cancers are highly susceptible to microbial infections due to the invasive nature of cancer treatment approaches. This study was designed to investigate the chemical profile of herba Anthriscii cerefoli methanolic extract by applying UHPLC-LTQ OrbiTrap MS4 analysis and to analyze its anti-glioblastoma and antimicrobial activities. This study revealed that methanolic extract of herba Anthrisc cerefolii contained phenolic acids and flavonoids, with 32 compounds being identified. Anti-glioblastoma activity was investigated in vitro using A172 glioblastoma cell line. The cytotoxic effects of the extract on A172 cells were compared to the same effect on primary human gingival fibroblast (HGF-1) cells. Decreased rate of proliferation and changes in cell morphology were detected upon treatment of A172 cells with the extract. The antimicrobial activity of extract was tested against Staphylococcus aureus and Candida species. The extract was active against the tested bacterium and yeasts, inhibiting free floating cells and microbial biofilms. This study is the first one to provide a detailed description of the chemical profile of A. cerefolium extract dealing with scientific insights into its anti-glioblastoma and antimicrobial activities