Clptm1 Downregulation Exerts Antiepileptic Activity by Regulating GABAAR-mediated Inhibitory Synaptic Transmission in PTZ-induced Epileptic Model

Abstract Background: Disruption of GABAAR synaptic clustering and a decrease number in their cell surface are thought to contribute to the alteration in the balance between excitatory and inhibitory neurotransmission, which contributes to seizure induction and propagation. Cleft lip and palate transmembrane protein 1 (Clptm1), a multi-pass transmembrane protein, has been showed that it is an intracellular molecule that controls forward trafficking of GABAAR. Clptm1 downregulating increased miniature inhibitory postsynaptic current (mIPSC) in vivo. Thus, Clptm1 controls phasic and tonic inhibitory transmission in brain. In this study, we hypothesized that Clptm1 may be involved in epileptic seizure by regulating GABAAR-mediated inhibitory synaptic transmission in epileptic model.Methods and Results: In PTZ-induced epileptic model, we found that Clptm1 was increased in temporal lobe epilepsy (TLE) patients as well as in epileptic model. Then, we showed that Clptm1 downregulation exerted antiepileptic activities in epileptic model, which was associated to the increased surface GABAARγ2 expression and mIPSCs amplitudes.Conclusions: Clptm1 downregulation exerted antiepileptic activities in epileptic model, thus, it may be a promising target for antiepileptic treatments.

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SP1-Mediated Upregulation of Long Noncoding RNA ZFAS1 Involved in Non-syndromic Cleft Lip and Palate via Inactivating WNT/β-Catenin Signaling Pathway

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2021.662780 ◽

2021 ◽

Vol 9 ◽

Author(s):

Shiyu Chen ◽

Zhonglin Jia ◽

Ming Cai ◽

Mujie Ye ◽

Dandan Wu ◽

...

Keyword(s):

Cell Proliferation ◽

Signaling Pathway ◽

Noncoding Rna ◽

Chondrogenic Differentiation ◽

Cleft Lip ◽

Cleft Lip And Palate ◽

Tissue Sample ◽

Human Umbilical Cord

Non-syndromic cleft lip and palate (NSCLP) is one of the most common congenital malformations with multifactorial etiology. Although long non-coding RNAs (lncRNAs) have been implicated in the development of lip and palate, their roles in NSCLP are not fully elucidated. This study aimed to investigate how dysregulated lncRNAs contribute to NSCLP. Using lncRNA sequencing, bioinformatics analysis, and clinical tissue sample detection, we identified that lncRNA ZFAS1 was significantly upregulated in NSCLP. The upregulation of ZFAS1 mediated by SP1 transcription factor (SP1) inhibited expression levels of Wnt family member 4 (WNT4) through the binding with CCCTC-binding factor (CTCF), subsequently inactivating the WNT/β-catenin signaling pathway, which has been reported to play a significant role on the development of lip and palate. Moreover, in vitro, the overexpression of ZFAS1 inhibited cell proliferation and migration in human oral keratinocytes and human umbilical cord mesenchymal stem cells (HUC-MSCs) and also repressed chondrogenic differentiation of HUC-MSCs. In vivo, ZFAS1 suppressed cell proliferation and numbers of chondrocyte in the zebrafish ethmoid plate. In summary, these results indicated that ZFAS1 may be involved in NSCLP by affecting cell proliferation, migration, and chondrogenic differentiation through inactivating the WNT/β-catenin signaling pathway.

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Cleft Lip and Palate Transmembrane Protein 1-Like Protein

10.32388/zw43og ◽

2020 ◽

Author(s):

Keyword(s):

Cleft Lip ◽

Cleft Lip And Palate ◽

Transmembrane Protein

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TMEM100 expression suppresses metastasis and enhances sensitivity to chemotherapy in gastric cancer

Biological Chemistry ◽

10.1515/hsz-2019-0161 ◽

2020 ◽

Vol 401 (2) ◽

pp. 285-296 ◽

Cited By ~ 1

Author(s):

Jinfu Zhuang ◽

Yongjian Huang ◽

Wei Zheng ◽

Shugang Yang ◽

Guangwei Zhu ◽

...

Keyword(s):

Gastric Cancer ◽

Transmembrane Protein ◽

Small Cell Lung Carcinoma ◽

Migration And Invasion ◽

Gene Encoding ◽

Cell Lung Carcinoma ◽

Chemotherapy Sensitivity ◽

Promising Target ◽

The Impact

AbstractThe gene encoding transmembrane protein 100 (TMEM100) was first discovered to be transcribed by the murine genome. It has been recently proven that TMEM100 contributes to hepatocellular carcinoma and non-small-cell lung carcinoma (NSCLC). This study investigates the impact of TMEM100 expression on gastric cancer (GC). TMEM100 expression was remarkably downregulated in GC samples compared to the surrounding non-malignant tissues (p < 0.01). Excessive TMEM100 expression prohibited the migration and invasion of GC cells without influencing their growth. However, TMEM100 knockdown restored their migration and invasion potential. Additionally, TMEM100 expression restored the sensitivity of GC cells to chemotherapeutic drugs such as 5-fluouracil (5-FU) and cisplatin. In terms of TMEM100 modulation, it was revealed that BMP9 rather than BMP10, is the upstream modulator of TM3M100. HIF1α downregulation modulated the impact of TMEM100 on cell migration, chemotherapy sensitivity and invasion in GC cells. Eventually, the in vivo examination of TMEM100 activity revealed that its upregulation prohibits the pulmonary metastasis of GC cells and increases the sensitivity of xenograft tumors to 5-FU treatment. In conclusion, TMEM100 serves as a tumor suppressor in GC and could be used as a promising target for the treatment of GC and as a predictor of GC clinical outcome.

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Synaptic integrative properties at hyperbaric pressure

Journal of Neurophysiology ◽

10.1152/jn.1988.60.4.1497 ◽

1988 ◽

Vol 60 (4) ◽

pp. 1497-1512 ◽

Cited By ~ 28

Author(s):

Y. Grossman ◽

J. J. Kendig

Keyword(s):

Synaptic Transmission ◽

Motor Neurons ◽

Repetitive Stimulation ◽

Inhibitory Synapses ◽

Synaptic Connections ◽

Paired Pulse ◽

Inhibitory Transmission ◽

Inhibitory Synaptic Transmission ◽

Hyperbaric Pressure ◽

Per Se

1. Because hyperbaric pressure profoundly depresses excitatory synaptic transmission, it has proved difficult to account for its excitatory effects in the CNS. We tested the hypothesis that hyperbaric pressure might increase excitation by enhancing facilitation and potentiation during repetitive synaptic activation, and/or by selectively depressing inhibitory synaptic transmission. Intracellular microelectrode recordings were obtained from crustacean muscle fibers innervated by single identifiable excitor and inhibitor motor neurons; the preparations were exposed to pressures of 0.1-10.1 MPa. 2. Hyperbaric pressure reduced the amplitude of the singly evoked excitatory junctional potential (EJP), enhanced paired-pulse facilitation, and increased the potentiation elicited by trains of stimuli. The potentiated EJP at 10.1 MPa approached the comparable response evoked at normobaric pressure. 3. Hyperbaric pressure also depressed inhibitory synaptic transmission, measured as depression of the EJP by the inhibitor motor neuron. However, pressure depressed excitatory and inhibitory synaptic transmission to the same extent. Thus there appears to be no selective effect of pressure on the GABA-activated chloride channel. The amplitude of the inhibited EJP at 10.1 MPa remained below that at normobaric pressure, even during repetitive stimulation. 4. The results do not support the hypothesis that pressure increases central excitation by selectively depressing inhibitory transmission per se; enhancement of potentiation, however, probably plays an important role. In this preparation, in which inhibitory transmission also displays facilitation, pressure did not increase overall excitation or alter the balance between excitation and inhibition. 5. These results predict that a pressure-excitable network should encompass excitatory synaptic connections which exhibit pronounced facilitation and inhibitory synapses with little or no facilitation.

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Tetraspanins TSP-12 and TSP-14 function redundantly to regulate the trafficking of the type II BMP receptor in Caenorhabditis elegans

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1918807117 ◽

2020 ◽

Vol 117 (6) ◽

pp. 2968-2977

Author(s):

Zhiyu Liu ◽

Herong Shi ◽

Anthony K. Nzessi ◽

Anne Norris ◽

Barth D. Grant ◽

...

Keyword(s):

Caenorhabditis Elegans ◽

Cell Surface ◽

Molecular Mechanisms ◽

Transmembrane Protein ◽

Expression Patterns ◽

Bmp Signaling ◽

Type I ◽

Type Ii ◽

Bmp Receptors

Tetraspanins are a unique family of 4-pass transmembrane proteins that play important roles in a variety of cell biological processes. We have previously shown that 2 paralogous tetraspanins in Caenorhabditis elegans, TSP-12 and TSP-14, function redundantly to promote bone morphogenetic protein (BMP) signaling. The underlying molecular mechanisms, however, are not fully understood. In this study, we examined the expression and subcellular localization patterns of endogenously tagged TSP-12 and TSP-14 proteins. We found that TSP-12 and TSP-14 share overlapping expression patterns in multiple cell types, and that both proteins are localized on the cell surface and in various types of endosomes, including early, late, and recycling endosomes. Animals lacking both TSP-12 and TSP-14 exhibit reduced cell-surface levels of the BMP type II receptor DAF-4/BMPRII, along with impaired endosome morphology and mislocalization of DAF-4/BMPRII to late endosomes and lysosomes. These findings indicate that TSP-12 and TSP-14 are required for the recycling of DAF-4/BMPRII. Together with previous findings that the type I receptor SMA-6 is recycled via the retromer complex, our work demonstrates the involvement of distinct recycling pathways for the type I and type II BMP receptors and highlights the importance of tetraspanin-mediated intracellular trafficking in the regulation of BMP signaling in vivo. As TSP-12 and TSP-14 are conserved in mammals, our findings suggest that the mammalian TSP-12 and TSP-14 homologs may also function in regulating transmembrane protein recycling and BMP signaling.

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Biallelic mutations in the TOGARAM1 gene cause a novel primary ciliopathy

Journal of Medical Genetics ◽

10.1136/jmedgenet-2020-106833 ◽

2020 ◽

pp. jmedgenet-2020-106833

Author(s):

Valeria Morbidoni ◽

Emanuele Agolini ◽

Kevin C Slep ◽

Luca Pannone ◽

Daniela Zuccarello ◽

...

Keyword(s):

Sensory Neurons ◽

Developmental Disorders ◽

Cleft Lip ◽

Cleft Lip And Palate ◽

Missense Variant ◽

Causative Role ◽

Biallelic Mutations ◽

The Impact

BackgroundDysfunction in non-motile cilia is associated with a broad spectrum of developmental disorders characterised by clinical heterogeneity. While over 100 genes have been associated with primary ciliopathies, with wide phenotypic overlap, some patients still lack a molecular diagnosis.ObjectiveTo investigate and functionally characterise the molecular cause of a malformation disorder observed in two sibling fetuses characterised by microphthalmia, cleft lip and palate, and brain anomalies.MethodsA trio-based whole exome sequencing (WES) strategy was used to identify candidate variants in the TOGARAM1 gene. In silico, in vitro and in vivo (Caenorhabditis elegans) studies were carried out to explore the impact of mutations on protein structure and function, and relevant biological processes.ResultsTOGARAM1 encodes a member of the Crescerin1 family of proteins regulating microtubule dynamics. Its orthologue in C. elegans, che-12, is expressed in a subset of sensory neurons and localises in the dendritic cilium where it is required for chemosensation. Nematode lines harbouring the corresponding missense variant in TOGARAM1 were generated by CRISPR/Cas9 technology. Although chemotaxis ability on a NaCl gradient was not affected, che-12 point mutants displayed impaired lipophilic dye uptake, with shorter and altered cilia in sensory neurons. Finally, in vitro analysis of microtubule polymerisation in the presence of wild-type or mutant TOG2 domain revealed a faster polymerisation associated with the mutant protein, suggesting aberrant tubulin binding.ConclusionsOur data are in favour of a causative role of TOGARAM1 variants in the pathogenesis of this novel disorder, connecting this gene with primary ciliopathy.

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Direct Interactions between Calcitonin-Like Receptor (CLR) and CGRP-Receptor Component Protein (RCP) Regulate CGRP Receptor Signaling

Endocrinology ◽

10.1210/en.2011-1459 ◽

2012 ◽

Vol 153 (4) ◽

pp. 1850-1860 ◽

Cited By ~ 25

Author(s):

Sophie C. Egea ◽

Ian M. Dickerson

Keyword(s):

Cell Surface ◽

Transmembrane Protein ◽

Direct Interaction ◽

Dominant Negative ◽

In Vivo Studies ◽

Cgrp Receptor ◽

Receptor Component ◽

Soluble Fusion Protein ◽

Component Protein

Calcitonin gene-related peptide (CGRP) is a neuropeptide with multiple neuroendocrine roles, including vasodilation, migraine, and pain. The receptor for CGRP is a G protein-coupled receptor (GPCR) that requires three proteins for function. CGRP binds to a heterodimer composed of the GPCR calcitonin-like receptor (CLR) and receptor activity-modifying protein (RAMP1), a single transmembrane protein required for pharmacological specificity and trafficking of the CLR/RAMP1 complex to the cell surface. In addition, the CLR/RAMP1 complex requires a third protein named CGRP-receptor component protein (RCP) for signaling. Previous studies have demonstrated that depletion of RCP from cells inhibits CLR signaling, and in vivo studies have demonstrated that expression of RCP correlates with CLR signaling and CGRP efficacy. It is not known whether RCP interacts directly with CLR to exert its effect. The current studies identified a direct interaction between RCP and an intracellular domain of CLR using yeast two-hybrid analysis and coimmunoprecipitation. When this interacting domain of CLR was expressed as a soluble fusion protein, it coimmunoprecipitated with RCP and inhibited signaling from endogenous CLR. Expression of this dominant-negative domain of CLR did not significantly inhibit trafficking of CLR to the cell surface, and thus RCP may not have a chaperone function for CLR. Instead, RCP may regulate CLR signaling in the cell membrane, and direct interaction between RCP and CLR is required for CLR activation. To date, RCP has been found to interact only with CLR and represents a novel neuroendocrine regulatory step in GPCR signaling.

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Poxvirus Complement Control Proteins Are Expressed on the Cell Surface through an Intermolecular Disulfide Bridge with the Viral A56 Protein

Journal of Virology ◽

10.1128/jvi.00372-10 ◽

2010 ◽

Vol 84 (21) ◽

pp. 11245-11254 ◽

Cited By ~ 14

Author(s):

Brian C. DeHaven ◽

Natasha M. Girgis ◽

Yuhong Xiao ◽

Paul N. Hudson ◽

Victoria A. Olson ◽

...

Keyword(s):

Cell Surface ◽

Transmembrane Protein ◽

Surface Expression ◽

Disulfide Bridge ◽

Eukaryotic Cell ◽

Cell Surface Expression ◽

Complement Control Proteins ◽

Express Cell ◽

Infected Cells

ABSTRACT The vaccinia virus (VACV) complement control protein (VCP) is an immunomodulatory protein that is both secreted from and expressed on the surface of infected cells. Surface expression of VCP occurs though an interaction with the viral transmembrane protein A56 and is dependent on a free N-terminal cysteine of VCP. Although A56 and VCP have been shown to interact in infected cells, the mechanism remains unclear. To investigate if A56 is sufficient for surface expression, we transiently expressed VCP and A56 in eukaryotic cell lines and found that they interact on the cell surface in the absence of other viral proteins. Since A56 contains three extracellular cysteines, we hypothesized that one of the cysteines may be unpaired and could therefore form a disulfide bridge with VCP. To test this, we generated a series of A56 mutants in which each cysteine was mutated to a serine, and we found that mutation of cysteine 162 abrogated VCP cell surface expression. We also tested the ability of other poxvirus complement control proteins to bind to VACV A56. While the smallpox homolog of VCP is able to bind VACV A56, the ectromelia virus (ECTV) VCP homolog is only able to bind the ECTV homolog of A56, indicating that these proteins may have coevolved. Surface expression of poxvirus complement control proteins may have important implications in viral pathogenesis, as a virus that does not express cell surface VCP is attenuated in vivo. This suggests that surface expression of VCP may contribute to poxvirus pathogenesis.

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