During embryogenesis, vertebral axial patterning is intricately regulated by multiple signaling networks. This study elucidates the role of protogenin (Prtg), an immunoglobulin superfamily member, in vertebral patterning control. Prtg knockout (Prtg) mice manifest anterior homeotic transformations in their vertebral columns and significant alterations in homeobox (Hox) gene expression.
View Article and Find Full Text PDFRetinal ganglion cells (RGCs) are essential for vision perception. In glaucoma and other optic neuropathies, RGCs and their optic axons undergo degenerative change and cell death; this can result in irreversible vision loss. Here we developed a rapid protocol for directly inducing RGC differentiation from human induced pluripotent stem cells (hiPSCs) by the overexpression of ATOH7, BRN3B, and SOX4.
View Article and Find Full Text PDFMicroglia, the immune cells of the central nervous system, play critical roles in brain physiology and pathology. We report a novel approach that produces, within 10 days, the differentiation of human induced pluripotent stem cells (hiPSCs) into microglia (iMG) by forced expression of both SPI1 and CEBPA. High-level expression of the main microglial markers and the purity of the iMG cells were confirmed by RT-qPCR, immunostaining, and flow cytometry analyses.
View Article and Find Full Text PDFAlzheimer's disease (AD) is the most common type of dementia and also one of the leading causes of death worldwide. However, the underlying mechanisms remain unclear, and currently there is no drug treatment that can prevent or cure AD. Here, we have applied the advantages of using induced pluripotent stem cell (iPSC)-derived neurons (iNs) from AD patients, which are able to offer human-specific drug responsiveness, in order to evaluate therapeutic candidates for AD.
View Article and Find Full Text PDFBased on the protein kinase A (PKA)/GSK3β interaction protein (GSKIP)/glycogen synthase kinase 3β (GSK3β) axis, we hypothesized that these might play a role in Tau phosphorylation. Here, we report that the phosphorylation of Tau Ser409 in SHSY5Y cells was increased by overexpression of GSKIP WT more than by PKA- and GSK3β-binding defective mutants (V41/L45 and L130, respectively). We conducted in vitro assays of various kinase combinations to show that a combination of GSK3β with PKA but not Ca/calmodulin-dependent protein kinase II (CaMK II) might provide a conformational shelter to harbor Tau Ser409.
View Article and Find Full Text PDFCongenital heart defects, dysmorphic facial features and intellectual developmental disorders (CHDFIDD) syndrome in humans was recently associated with mutation in gene. In order to assess the loss of function of Cdk13 during mouse development, we employed gene trap knock-out (KO) allele in gene. Embryonic lethality of Cdk13-deficient animals was observed by the embryonic day (E) 16.
View Article and Find Full Text PDFMutations in RAB18, a member of small G protein, cause Warburg micro syndrome (WARBM), whose clinical features include vision impairment, postnatal microcephaly, and lower limb spasticity. Previously, our Rab18 mice exhibited hind limb weakness and spasticity as well as signs of axonal degeneration in the spinal cord and lumbar spinal nerves. However, the cellular and molecular function of RAB18 and its roles in the pathogenesis of WARBM are still not fully understood.
View Article and Find Full Text PDFThe pathogenesis of Parkinson's disease (PD) is not completely understood, Zinc (Zn(2+) ) and dopamine (DA) have been shown to involve in the degeneration of dopaminergic cells. By microarray analysis, we identified Gadd45b as a candidate molecule that mediates Zn(2+) and DA-induced cell death; the mRNA and protein levels of Gadd45b are increased by Zn(2+) treatment and raised to an even higher level by Zn(2+) plus DA treatment. Zn(2+) plus DA treatment-induced PC12 cell death was enhanced when there was over-expression of Gadd45b and was decreased by knock down of Gadd45b.
View Article and Find Full Text PDFDNA damage response (DDR) pathways are critical for ensuring that replication stress and various types of DNA lesion do not perturb production of neural cells during development. Cdk12 maintains genomic stability by regulating expression of DDR genes. Mutant mice in which Cdk12 is conditionally deleted in neural progenitor cells (NPCs) die after birth and exhibit microcephaly with a thinner cortical plate and an aberrant corpus callosum.
View Article and Find Full Text PDFMutations in the gene of RAB18, a member of Ras superfamily of small G-proteins, cause Warburg Micro Syndrome (WARBM) which is characterized by defective neurodevelopmental and ophthalmological phenotypes. Despite loss of Rab18 had been reported to induce disruption of the endoplasmic reticulum structure and neuronal cytoskeleton organization, parts of the pathogenic mechanism caused by RAB18 mutation remain unclear. From the N-ethyl-N-nitrosourea (ENU)-induced mutagenesis library, we identified a mouse line whose Rab18 was knocked out.
View Article and Find Full Text PDFObjective: To describe a novel mutation in TRK-fused gene (TFG) as a new cause of dominant axonal Charcot-Marie-Tooth disease (CMT) identified by exome sequencing and further characterized by in vitro functional studies.
Methods: Exome sequencing and linkage analysis were utilized to investigate a large Taiwanese family with a dominantly inherited adult-onset motor and sensory axonal neuropathy in which mutations in common CMT2-implicated genes had been previously excluded. Functional effects of the mutant gene products were investigated in vitro.
Cdk12 and Cdk13 are Cdc2-related proteins that share 92% identity in their kinase domains. Using in situ hybridization and Western blot analysis, we detected the expression of Cdk12 and Cdk13 mRNAs and their proteins in developing mouse embryos, especially during development of the nervous system. We explored the roles of Cdk12 and Cdk13 in neuronal differentiation using the P19 neuronal differentiation model.
View Article and Find Full Text PDFBackground: The axon guidance cue molecule Slit2 has been shown to suppress cancer cell invasion. However, the role of Slit2 in growth inhibition is still controversial. The authors identified a novel exon 15 (AKEQYFIP)-deleted slit2, located at the end of the second leucine-rich repeat (LRR2).
View Article and Find Full Text PDFNa(+)/Ca(2+) exchanger (NCX) is one of the major mechanisms for removing Ca(2+) from the cytosol especially in cardiac myocytes and neurons, where their physiological activities are triggered by an influx of Ca(2+). NCX contains a large intracellular loop (NCXIL) that is responsible for regulating NCX activity. Recent evidence has shown that proteins, including kinases and phosphatases, associate with NCX1IL to form a NCX1 macromolecular complex.
View Article and Find Full Text PDFMany Ig superfamily members are expressed in the developing nervous system, but the functions of these molecules during neurogenesis are not all clear. Here, we explore the expression and function of one of members of this superfamily, protogenin (PRTG), in the developing nervous system. Expression of PRTG protein is strong in the neural tube of mouse embryos between embryonic days 7.
View Article and Find Full Text PDFIn the present study, we characterized the Ca2+ responses and secretions induced by various secretagogues in mouse chromaffin cells. Activation of the acetylcholine receptor (AChR) by carbachol induced a transient intracellular Ca2+ concentration ([Ca2+](i)) increase followed by two phases of [Ca2+](i) decay and a burst of exocytic events. The contribution of the subtypes of AChRs to carbachol-induced responses was examined.
View Article and Find Full Text PDFPurpose: To investigate OPA1 gene mutations in Chinese patients with autosomal dominant optic atrophy and sporadic optic atrophy.
Design: Molecular genetic studies and observational case series.
Participants: Twenty-four patients from 10 unrelated Chinese pedigrees of autosomal-dominant optic atrophy, 35 isolated cases with bilateral optic atrophy of unknown cause, and 50 unrelated normal controls.
Am J Physiol Regul Integr Comp Physiol
July 2007
The molecular and cellular mechanisms behind glycogen metabolism and the energy metabolite translocation between mammal neurons and astrocytes have been well studied. A similar mechanism is proposed for rapid mobilization of local energy stores to support energy-dependent transepithelial ion transport in gills of the Mozambique tilapia (Oreochromis mossambicus). A novel gill glycogen phosphorylase isoform (tGPGG), which catalyzes the initial degradation of glycogen, was identified in branchial epithelial cells of O.
View Article and Find Full Text PDFBiochem Biophys Res Commun
March 2007
Due to the strong sequence homology it has been suggested that CDC2L5 and CDK12 belong to a high molecular weight subfamily of CDC2 family with PITAI/VRE motifs [F. Marques, J.L.
View Article and Find Full Text PDFMutations in the optic atrophy type 1 (OPA1) gene give rise to human autosomal dominant optic atrophy. The purpose of this study is to investigate OPA1 protein expression in the human retina and optic nerve. A rabbit polyclonal antiserum was generated using a fusion protein covering amino acids 647 to 808 of the human OPA1 protein as the immunogenic antigen.
View Article and Find Full Text PDFCrkRS is a Cdc2-related protein kinase that contains an arginine- and serine-rich (SR) domain, a characteristic of the SR protein family of splicing factors, and is proposed to be involved in RNA processing. However, whether it acts together with a cyclin and at which steps it may function to regulate RNA processing are not clear. Here, we report that CrkRS interacts with cyclin L1 and cyclin L2, and thus rename it as the long form of cyclin-dependent kinase 12 (CDK12(L)).
View Article and Find Full Text PDFPurpose: Vitronectin is a secreted glycoprotein present in blood plasma and is present in the extracellular matrix of many tissues. It was found in the retinal cDNA library that contains genes whose expression is upregulated after optic nerve injury in a previous study. The purpose of this study was to assess the temporal and spatial changes in expression of vitronectin and integrin alphav in the retina following optic nerve injury.
View Article and Find Full Text PDFAntimicrob Agents Chemother
March 2005
The ERG3 gene in Candida albicans was identified as a gene whose mRNA level was higher in the cph1/cph1 efg1/efg1 double mutant than in the wild-type cells. Further study showed that Efg1, but not Cph1, negatively regulated ERG3. Mutations in EFG1 consistently increased the susceptibility of the cells to antifungal agents.
View Article and Find Full Text PDFNeural information processed through the striatum of the basal ganglia is crucial for sensorimotor and psychomotor functions. Genes that are highly expressed in the striatum during development may be involved in neural development and plasticity in the striatum. We report in the present study the identification of a previously uncharacterized mammalian member of the nocA/elB/tlp-1 family, Nolz-1, that is preferentially expressed at high levels in the developing striatum.
View Article and Find Full Text PDFNF-kappaB (nuclear factor kappaB) proteins are key transcription factors that regulate gene expression in response to various extracellular stimuli. The pathway leading to the activation of NF-kappaB involves a complicated network that includes a number of signalling molecules. The recent identification of a wide range of negative regulators of NF-kappaB has given another layer of complexity in NF-kappaB activation.
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