Project description:Snail, a family of transcriptional repressors implicated in cell movement, has been correlated with tumour invasivity. The Plasminogen Activation system (PAs), including urokinase (uPA), its receptor (uPAR), and its inhibitor (PAI-1), also plays a key role in cancer invasion and metastasis, either through proteolytic degradation or by non proteolytic modulation of cell adhesion and migration. Thus, Snail and PAs both influence those processes and are over-expressed in cancers. In this study we aimed to determine first whether Snail activity is correlated with PAs components expression and second how this correlation can influence tumoral cell migration. Keywords: Tumoral migration Comparison the invasive breast cancer cell-line MDA-MB-231 expressing Snail (MDA-Neo) with its derived clone expressing a dominant negative form of Snail (Snail-DN). Expression of PAs mRNAs was performed by cDNA microarrays and real time quantitative RT-PCR. Wound healing assay was used to determine cell migration. PAI-1â??s distribution was assessed by immunostaining.
Project description:Snail, a family of transcriptional repressors implicated in cell movement, has been correlated with tumour invasivity. The Plasminogen Activation system (PAs), including urokinase (uPA), its receptor (uPAR), and its inhibitor (PAI-1), also plays a key role in cancer invasion and metastasis, either through proteolytic degradation or by non proteolytic modulation of cell adhesion and migration. Thus, Snail and PAs both influence those processes and are over-expressed in cancers. In this study we aimed to determine first whether Snail activity is correlated with PAs components expression and second how this correlation can influence tumoral cell migration. Keywords: Tumoral migration
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.
Project description:Plasminogen activator inhibitor-2 regulates immune response in kidney injury and renal aging mpact of plasminogen activator inhibitor-2 in kidney injury and renal aging
Project description:As the evolution of miRNA genes has been found to be one of the important factors in formation of the modern type of man, we performed a comparative analysis of the evolution of miRNA genes in two archaic hominines, Homo sapiens neanderthalensis and Homo sapiens denisova, and elucidated the expression of their target mRNAs in bain.A comparative analysis of the genomes of primates, including species in the genus Homo, identified a group of miRNA genes having fixed substitutions with important implications for the evolution of Homo sapiens neanderthalensis and Homo sapiens denisova. The mRNAs targeted by miRNAs with mutations specific for Homo sapiens denisova exhibited enhanced expression during postnatal brain development in modern humans. By contrast, the expression of mRNAs targeted by miRNAs bearing variations specific for Homo sapiens neanderthalensis was shown to be enhanced in prenatal brain development.Our results highlight the importance of changes in miRNA gene sequences in the course of Homo sapiens denisova and Homo sapiens neanderthalensis evolution. The genetic alterations of miRNAs regulating the spatiotemporal expression of multiple genes in the prenatal and postnatal brain may contribute to the progressive evolution of brain function, which is consistent with the observations of fine technical and typological properties of tools and decorative items reported from archaeological Denisovan sites. The data also suggest that differential spatial-temporal regulation of gene products promoted by the subspecies-specific mutations in the miRNA genes might have occurred in the brains of Homo sapiens denisova and Homo sapiens neanderthalensis, potentially contributing to the cultural differences between these two archaic hominines.
Project description:PurposeWe investigated the evidence of recent positive selection in the human phototransduction system at single nucleotide polymorphism (SNP) and gene level.MethodsSNP genotyping data from the International HapMap Project for European, Eastern Asian, and African populations was used to discover differences in haplotype length and allele frequency between these populations. Numeric selection metrics were computed for each SNP and aggregated into gene-level metrics to measure evidence of recent positive selection. The level of recent positive selection in phototransduction genes was evaluated and compared to a set of genes shown previously to be under recent selection, and a set of highly conserved genes as positive and negative controls, respectively.ResultsSix of 20 phototransduction genes evaluated had gene-level selection metrics above the 90th percentile: RGS9, GNB1, RHO, PDE6G, GNAT1, and SLC24A1. The selection signal across these genes was found to be of similar magnitude to the positive control genes and much greater than the negative control genes.ConclusionsThere is evidence for selective pressure in the genes involved in retinal phototransduction, and traces of this selective pressure can be demonstrated using SNP-level and gene-level metrics of allelic variation. We hypothesize that the selective pressure on these genes was related to their role in low light vision and retinal adaptation to ambient light changes. Uncovering the underlying genetics of evolutionary adaptations in phototransduction not only allows greater understanding of vision and visual diseases, but also the development of patient-specific diagnostic and intervention strategies.
Project description:To screen the genes regulated by wt-Snail and non-acetylated Snail The successful development of cancer metastasis requires two major events: the reprogramming of cancer cells to increase their migration and tumor-initiation capabilities; and the remodeling of the tumor microenvironment to facilitate invasion and colonization of cancer cells. Epithelial-mesenchymal transition (EMT) is a crucial mechanism for reprogramming cancer cells to possess tumor initiation and migration capabilities1,2. However, the role of EMT in the interplay between tumor and host cells is largely unknown. The EMT regulator Snail is mainly known as a transcriptional repressor of the adhesion protein E-cadherin, whose repression is considered to be a key step in initiating metastasis3,4. We previously found that Snail can also act as an activator that induces the transcription of ERCC15 and IL86. Here we show that Snail is acetylated by CREB-binding protein (CBP) and that Snail and CBP co-occupy the promoters of target genes to activate transcription of the target genes. Furthermore, Snail activates the expression of a panel of cytokine genes, including TNFa (which forms a positive feedback loop with Snail to amplify the signal) and CCL2 and CCL5 (which facilitate the recruitment of macrophages by cancer cells). Our results demonstrate a novel function for Snail, providing new understanding of the recruitment of host cells to tumor sites during metastatic evolution. Establish stable transfectants of pCDH-Snail and pCDH-Snail2R in FaDu cells and analyze the mRNA expression level of by cDNA microarray. FaDu transfected with pCDH vector was used as a control experiment.
Project description:Cortical thickness has been investigated since the beginning of the 20th century, but we do not know how similar the cortical thickness profiles among humans are. In this study, the local similarity of cortical thickness profiles was investigated using sliding window methods. Here, we show that approximately 5% of the cortical thickness profiles are similarly expressed among humans while 45% of the cortical thickness profiles show a high level of heterogeneity. Therefore, heterogeneity is the rule, not the exception. Cortical thickness profiles of somatosensory homunculi and the anterior insula are consistent among humans, while the cortical thickness profiles of the motor homunculus are more variable. Cortical thickness profiles of homunculi that code for muscle position and skin stimulation are highly similar among humans despite large differences in sex, education, and age. This finding suggests that the structure of these cortices remains well preserved over a lifetime. Our observations possibly relativize opinions on cortical plasticity.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.