RESUMO
Smooth muscle cell (SMC) phenotypic modulation, primarily driven by PDGFRß signaling, is implicated in occlusive cardiovascular diseases. However, the promotive and restrictive regulation mechanism of PDGFRß and the role of protein tyrosine phosphatase non-receptor type 14 (PTPN14) in neointimal hyperplasia remain unclear. Our study observes a marked upregulation of PTPN14 in SMCs during neointimal hyperplasia. PTPN14 overexpression exacerbates neointimal hyperplasia in a phosphatase activity-dependent manner, while SMC-specific deficiency of PTPN14 mitigates this process in mice. RNA-seq indicates that PTPN14 deficiency inhibits PDGFRß signaling-induced SMC phenotypic modulation. Moreover, PTPN14 interacts with intracellular region of PDGFRß and mediates its dephosphorylation on Y692 site. Phosphorylation of PDGFRßY692 negatively regulates PDGFRß signaling activation. The levels of both PTPN14 and phospho-PDGFRßY692 are correlated with the degree of stenosis in human coronary arteries. Our findings suggest that PTPN14 serves as a critical modulator of SMCs, promoting neointimal hyperplasia. PDGFRßY692, dephosphorylated by PTPN14, acts as a self-inhibitory site for controlling PDGFRß activation.
Assuntos
Hiperplasia , Miócitos de Músculo Liso , Neointima , Receptor beta de Fator de Crescimento Derivado de Plaquetas , Transdução de Sinais , Receptor beta de Fator de Crescimento Derivado de Plaquetas/metabolismo , Receptor beta de Fator de Crescimento Derivado de Plaquetas/genética , Animais , Hiperplasia/metabolismo , Miócitos de Músculo Liso/metabolismo , Miócitos de Músculo Liso/patologia , Humanos , Neointima/metabolismo , Neointima/patologia , Camundongos , Fosforilação , Masculino , Proteínas Tirosina Fosfatases não Receptoras/metabolismo , Proteínas Tirosina Fosfatases não Receptoras/genética , Camundongos Endogâmicos C57BL , Camundongos Knockout , Vasos Coronários/patologia , Vasos Coronários/metabolismo , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patologiaRESUMO
Triple-negative breast cancer (TNBC) poses a challenging prognosis due to early metastasis driven by anoikis resistance. Identifying crucial regulators to overcome this resistance is vital for improving patient outcomes. In this study, a genome-wide CRISPR/Cas9 knockout screen in TNBC cells has identified tyrosine-protein phosphatase nonreceptor type 14 (PTPN14) as a key regulator of anoikis resistance. PTPN14 expression has shown a progressive decrease from normal breast tissue to metastatic tumors. Overexpressing PTPN14 has induced anoikis and inhibited cell proliferation in TNBC cells, while normal human breast cells are unaffected. Mechanistically, PTPN14 is identified as a key factor in dephosphorylating breast cancer antiestrogen resistance 3, a novel substrate, leading to the subsequent inhibition of PI3K/AKT and ERK signaling pathways. Local delivery of in vitro transcribed PTPN14 mRNA encapsulated by lipid nanoparticles in a TNBC mouse model has effectively inhibited tumor growth and metastasis, prolonging survival. The study underscores PTPN14 as a potential therapeutic target for metastatic TNBC, with the therapeutic strategy based on mRNA expression of PTPN14 demonstrating clinical application prospects in alleviating the burden of both primary tumors and metastatic disease.
Assuntos
Anoikis , Nanopartículas , Proteínas Tirosina Fosfatases não Receptoras , RNA Mensageiro , Neoplasias de Mama Triplo Negativas , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Anoikis/genética , Camundongos , Animais , Humanos , Feminino , Proteínas Tirosina Fosfatases não Receptoras/genética , Proteínas Tirosina Fosfatases não Receptoras/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Linhagem Celular Tumoral , Modelos Animais de Doenças , Proliferação de Células/genética , LipossomosRESUMO
Lafora disease (LD) is a syndrome of progressive myoclonic epilepsy and cumulative neurocognitive deterioration caused by recessively inherited genetic lesions of EPM2A (laforin) or NHLRC1 (malin). Neuropsychiatric symptomatology in LD is thought to be directly downstream of neuronal and astrocytic polyglucosan aggregates, termed Lafora bodies (LBs), which faithfully accumulate in an age-dependent manner in all mouse models of LD. In this study, we applied home-cage monitoring to examine the extent of neurobehavioral deterioration in a model of malin-deficient LD as a means to identify robust preclinical endpoints that may guide the selection of novel genetic treatments. At 6 weeks, â¼6-7 months, and â¼12 months of age, malin-deficient mice ("KO") and wild-type (WT) littermates underwent a standardized home-cage behavioral assessment designed to non-obtrusively appraise features of rest/arousal, consumptive behaviors, risk aversion, and voluntary wheel-running. At all timepoints, and over a range of metrics that we report transparently, WT and KO mice were essentially indistinguishable. In contrast, within WT mice compared across the same timepoints, we identified age-related nocturnal hypoactivity, diminished sucrose preference, and reduced wheel-running. Neuropathological examinations in subsets of the same mice revealed expected age-dependent LB accumulation, gliosis, and microglial activation in cortical and subcortical brain regions. At 12 months of age, despite the burden of neocortical LBs, we did not identify spontaneous seizures during an electroencephalographic (EEG) survey, and KO and WT mice exhibited similar spectral EEG features. However, in an in vitro assay of neocortical function, paroxysmal bursts of network activity (UP states) in KO slices were more prolonged at 3 and 6 months of age, but similar to WT at 12 months. KO mice displayed a distinct response to pentylenetetrazole, with a greater incidence of clonic seizures and a more pronounced postictal suppression of movement, feeding, and drinking behavior. Together, these results highlight the clinicopathologic dissociation in a mouse model of LD, where the accrual of LBs may latently modify cortical circuit function and seizure threshold without clinically meaningful changes in home-cage behavior. Our findings allude to a delay between LB accumulation and neurobehavioral decline in LD: one that may provide a window for treatment, and whose precise duration may be difficult to ascertain within the typical lifespan of a laboratory mouse.
Assuntos
Comportamento Animal , Doença de Lafora , Camundongos Knockout , Ubiquitina-Proteína Ligases , Animais , Doença de Lafora/genética , Doença de Lafora/patologia , Camundongos , Comportamento Animal/fisiologia , Ubiquitina-Proteína Ligases/deficiência , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Camundongos Endogâmicos C57BL , Masculino , Modelos Animais de Doenças , Corpos de Inclusão/patologia , Corpos de Inclusão/metabolismo , Proteínas Tirosina Fosfatases não Receptoras/genética , Proteínas Tirosina Fosfatases não Receptoras/deficiência , Proteínas Tirosina Fosfatases não Receptoras/metabolismo , Encéfalo/metabolismo , Encéfalo/patologiaRESUMO
OBJECTIVE: To explore the clinical and genetic characteristics of two newborns with Central nuclear myopathy (CNM). METHODS: Two newborns with CNM diagnosed clinically at Wuhan Children's Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology in April 2019 and November 2021 were selected as the study subjects, and their clinical data was collected. Both newborns and their parents were subjected chromosomal karyotyping analysis and whole exome sequencing (WES). Candidate variants were verified by Sanger sequencing. Pathogenicity of the candidate variants was evaluated based on the guidelines from the American College of Medical Genetics and Genomics (ACMG). RESULTS: Patient 1 was a male neonate and Patient 2 was a 20-day-old male infant. Both newborns had featured difficulty in breathing and swallowing. WES revealed that both had harbored hemizygous variants of the MTM1 gene, which were verified by Sanger sequencing. Patient 1 had harbored a c.1261A>G variant. Based on the ACMG guidelines, it was rated as pathogenic (PVS1+PM2_Supporting+PP3). Patient 2 harbored a c.342delT variant, which was also rated as pathogenic (PVS1+PM2_Supporting+PP3). CONCLUSION: The c.1261A>G and c.342delT variants of the MTM1 gene probably underlay the pathogenesis of CNM in the two patients.
Assuntos
Miopatias Congênitas Estruturais , Humanos , Masculino , Miopatias Congênitas Estruturais/genética , Recém-Nascido , Mutação , Sequenciamento do Exoma , Proteínas Tirosina Fosfatases não Receptoras/genética , Testes GenéticosRESUMO
X-linked myotubular myopathy (XLMTM) is a rare congenital myopathy. In February 2021, a male neonate was admitted to the West China Second University Hospital, Sichuan University, with clinical manifestations of hypotonia, accompanied by distinctive facial features, and requiring continuous ventilatory support. He was born prematurely at 36+2 weeks gestation and developed respiratory distress postnatally, followed by difficulty in weaning from mechanical ventilation. Additional clinical features included hypotonia of the limbs, swallowing dysfunction, and specific facial characteristics (elongated limbs, narrow face, high-arched palate, wrist drop, empty scrotum, elongated fingers/toes). Genetic testing confirmed the diagnosis of XLMTM. Whole-exome sequencing analysis of the family revealed no mutations in the father, paternal grandfather, or paternal grandmother, while the mother had a heterozygous mutation. The pathogenic mutation was identified as MTM1 gene (OMIM: 300415), chromosome position chrX-150649714, with a nucleotide change of c.868-2A>C. The patient exhibited typical facial features. Genetic testing is crucial for accurate diagnosis of XLMTM in infants presenting with abnormal muscle tone and distinctive facial features.
Assuntos
Mutação , Miopatias Congênitas Estruturais , Proteínas Tirosina Fosfatases não Receptoras , Humanos , Miopatias Congênitas Estruturais/genética , Miopatias Congênitas Estruturais/diagnóstico , Masculino , Recém-Nascido , Proteínas Tirosina Fosfatases não Receptoras/genética , Sequenciamento do Exoma , Testes Genéticos , Hipotonia Muscular/genéticaRESUMO
Protein tyrosine phosphatase non-receptor type 21 (PTPN21) is a cytosolic protein tyrosine phosphatase that regulates cell growth and invasion. Due to its oncogenic properties, PTPN21 has recently emerged as a potential therapeutic target for cancer. In this study, the three-dimensional structure of the PTPN21 FERM domain was determined at 2.1â Å resolution by X-ray crystallography. The crystal structure showed that this domain harbors canonical FERM folding and consists of three subdomains that are tightly packed via highly conserved intramolecular hydrophobic interactions. Consistent with this, the PTPN21 FERM domain shares high structural homology with several other FERM domains. Moreover, structural superimposition demonstrated two putative protein-binding sites of the PTPN21 FERM domain, which are presumed to be associated with interaction with its binding partner, kinesin family member 1C. Thus, these data suggest that the FERM domain of PTPN21 serves as a module that mediates protein-protein interaction, like other FERM domains.
Assuntos
Modelos Moleculares , Humanos , Cristalografia por Raios X , Ligação Proteica , Sítios de Ligação , Sequência de Aminoácidos , Domínios Proteicos , Proteínas Tirosina Fosfatases não Receptoras/química , Proteínas Tirosina Fosfatases não Receptoras/metabolismo , Proteínas Tirosina Fosfatases não Receptoras/genética , Interações Hidrofóbicas e Hidrofílicas , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismoRESUMO
The rapid antidepressant effects of ketamine depend on the N-methyl-D-aspartate (NMDA) receptor containing 2B subunit (NR2B), whose function is influenced by its phosphorylated regulation and distribution within and outside synapses. It remains unclear if ketamine's rapid onset of antidepressant effects relies on the dynamic phosphorylated regulation of NR2B within and outside synapses. Here, we show that ketamine rapidlyalleviated depression-like behaviors and normalized abnormal expression of pTyr1472NR2B and striatal-enriched protein tyrosine phosphatase (STEP) 61 within and outside synapses in the medial prefrontal cortex (mPFC) induced by chronic unpredictable stress (CUS) and conditional knockdown of STEP 61, a key phosphatase of NR2B, within 1â¯hour after administration Together, our results delineate the rapid initiation of ketamine's antidepressant effects results from the restoration of NR2B phosphorylation homeostasis within and outside synapses. The dynamic regulation of phosphorylation of NR2B provides a new perspective for developing new antidepressant strategies.
Assuntos
Antidepressivos , Depressão , Ketamina , Camundongos Endogâmicos C57BL , Córtex Pré-Frontal , Receptores de N-Metil-D-Aspartato , Receptores de N-Metil-D-Aspartato/metabolismo , Ketamina/farmacologia , Animais , Fosforilação/efeitos dos fármacos , Antidepressivos/farmacologia , Antidepressivos/uso terapêutico , Masculino , Córtex Pré-Frontal/metabolismo , Córtex Pré-Frontal/efeitos dos fármacos , Depressão/tratamento farmacológico , Depressão/metabolismo , Proteínas Tirosina Fosfatases não Receptoras/metabolismo , Proteínas Tirosina Fosfatases não Receptoras/genética , Tirosina/metabolismo , Camundongos , Estresse Psicológico/metabolismo , Estresse Psicológico/tratamento farmacológico , Sinapses/efeitos dos fármacos , Sinapses/metabolismo , Comportamento Animal/efeitos dos fármacosRESUMO
The myotubularin family, encompassing myotubularin 1 (MTM1) and 14 myotubularin-related proteins (MTMRs), represents a conserved group of phosphatases featuring a protein tyrosine phosphatase domain. Nine members are characterized by an active phosphatase domain C(X)5R, dephosphorylating the D3 position of PtdIns(3)P and PtdIns(3,5)P2. Mutations in myotubularin genes result in human myopathies, and several neuropathies including X-linked myotubular myopathy and Charcot-Marie-Tooth type 4B. MTM1, MTMR6 and MTMR14 also contribute to Ca2+ signaling and Ca2+ homeostasis that play a key role in many MTM-dependent myopathies and neuropathies. Here we explore the evolving roles of MTM1/MTMRs, unveiling their influence on critical aspects of Ca2+ signaling pathways.
Assuntos
Sinalização do Cálcio , Cálcio , Homeostase , Proteínas Tirosina Fosfatases não Receptoras , Humanos , Proteínas Tirosina Fosfatases não Receptoras/metabolismo , Proteínas Tirosina Fosfatases não Receptoras/genética , Cálcio/metabolismo , Animais , Miopatias Congênitas Estruturais/genética , Miopatias Congênitas Estruturais/metabolismo , MutaçãoRESUMO
Lafora disease is a rare and fatal form of progressive myoclonic epilepsy typically occurring early in adolescence. The disease results from mutations in the EPM2A gene, encoding laforin, or the EPM2B gene, encoding malin. Laforin and malin work together in a complex to control glycogen synthesis and prevent the toxicity produced by misfolded proteins via the ubiquitin-proteasome system. Disruptions in either protein cause alterations in this complex, leading to the formation of Lafora bodies containing abnormal, insoluble, and hyperphosphorylated forms of glycogen. We used the Epm2a-/- knockout mouse model of Lafora disease to apply gene therapy by administering intracerebroventricular injections of a recombinant adeno-associated virus carrying the human EPM2A gene. We evaluated the effects of this treatment through neuropathological studies, behavioral tests, video-electroencephalography, electrophysiological recordings, and proteomic/phosphoproteomic analysis. Gene therapy ameliorated neurological and histopathological alterations, reduced epileptic activity and neuronal hyperexcitability, and decreased the formation of Lafora bodies. Moreover, differential quantitative proteomics and phosphoproteomics revealed beneficial changes in various molecular pathways altered in Lafora disease. Our results represent proof of principle for gene therapy with the coding region of the human EPM2A gene as a treatment for EPM2A-related Lafora disease.
Assuntos
Dependovirus , Modelos Animais de Doenças , Terapia Genética , Doença de Lafora , Camundongos Knockout , Proteínas Tirosina Fosfatases não Receptoras , Doença de Lafora/terapia , Doença de Lafora/genética , Doença de Lafora/metabolismo , Animais , Terapia Genética/métodos , Proteínas Tirosina Fosfatases não Receptoras/genética , Proteínas Tirosina Fosfatases não Receptoras/metabolismo , Camundongos , Dependovirus/genética , Humanos , Vetores Genéticos/genética , Vetores Genéticos/administração & dosagem , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Eletroencefalografia , Proteômica/métodosRESUMO
Myogenesis is a multistep process that requires a spatiotemporal regulation of cell events resulting finally in myoblast fusion into multinucleated myotubes. Most major insights into the mechanisms underlying fusion seem to be conserved from insects to mammals and include the formation of podosome-like protrusions (PLPs) that exert a driving force toward the founder cell. However, the machinery that governs this process remains poorly understood. In this study, we demonstrate that MTM1 is the main enzyme responsible for the production of phosphatidylinositol 5-phosphate, which in turn fuels PI5P 4-kinase α to produce a minor and functional pool of phosphatidylinositol 4,5-bisphosphate that concentrates in PLPs containing the scaffolding protein Tks5, Dynamin-2, and the fusogenic protein Myomaker. Collectively, our data reveal a functional crosstalk between a PI-phosphatase and a PI-kinase in the regulation of PLP formation.
Assuntos
Fusão Celular , Mioblastos , Fosfatos de Fosfatidilinositol , Podossomos , Animais , Fosfatos de Fosfatidilinositol/metabolismo , Camundongos , Mioblastos/metabolismo , Mioblastos/citologia , Podossomos/metabolismo , Proteínas Tirosina Fosfatases não Receptoras/metabolismo , Proteínas Tirosina Fosfatases não Receptoras/genética , Desenvolvimento Muscular/fisiologiaRESUMO
OBJECTIVES: This study aims to investigate the role of excessive Protein Tyrosine Phosphatase Non-Receptor Type 21 (PTPN21) in the proliferation of Acute Lymphoblastic Leukemia (ALL) cells with EGF stimulation. METHODS: PTPN21 was overexpressed in ALL cell lines by lentiviral transfection. Apoptosis was assayed by Annexin V/7-AAD staining. The proliferation and cell cycle of EGF-treated ALL cells were assessed by MTT and Ki-67/7-AAD staining respectively. The phosphorylation of Src tyrosine kinase and mediators of distinct MAPK pathways were assessed by Western blot. RESULTS: Overexpression of PTPN21 had minimal effect on the apoptosis of ALL cells, but significantly promoted the proliferation and cell cycle progression of ALL cells stimulated with EGF. The activity of Src tyrosine kinase and the MAPK pathways was elevated. Inhibition of MAPK pathways by specific inhibitors mitigated this pro-proliferative effect of excessive PTPN21 on EGF-stimulated ALL cells. CONCLUSION: PTPN21 may facilitate ALL progression by promoting cell proliferation via the Src/MAPK signaling pathways.
Assuntos
Proliferação de Células , Fator de Crescimento Epidérmico , Sistema de Sinalização das MAP Quinases , Leucemia-Linfoma Linfoblástico de Células Precursoras , Proteínas Tirosina Fosfatases não Receptoras , Humanos , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Fator de Crescimento Epidérmico/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Proteínas Tirosina Fosfatases não Receptoras/genética , Proteínas Tirosina Fosfatases não Receptoras/metabolismoRESUMO
Lafora disease (LD) is an autosomal recessive myoclonus epilepsy with onset in the teenage years leading to death within a decade of onset. LD is characterized by the overaccumulation of hyperphosphorylated, poorly branched, insoluble, glycogen-like polymers called Lafora bodies. The disease is caused by mutations in either EPM2A, encoding laforin, a dual specificity phosphatase that dephosphorylates glycogen, or EMP2B, encoding malin, an E3-ubiquitin ligase. While glycogen is a widely accepted laforin substrate, substrates for malin have been difficult to identify partly due to the lack of malin antibodies able to detect malin in vivo. Here we describe a mouse model in which the malin gene is modified at the C-terminus to contain the c-myc tag sequence, making an expression of malin-myc readily detectable. Mass spectrometry analyses of immunoprecipitates using c-myc tag antibodies demonstrate that malin interacts with laforin and several glycogen-metabolizing enzymes. To investigate the role of laforin in these interactions we analyzed two additional mouse models: malin-myc/laforin knockout and malin-myc/LaforinCS, where laforin was either absent or the catalytic Cys was genomically mutated to Ser, respectively. The interaction of malin with partner proteins requires laforin but is not dependent on its catalytic activity or the presence of glycogen. Overall, the results demonstrate that laforin and malin form a complex in vivo, which stabilizes malin and enhances interaction with partner proteins to facilitate normal glycogen metabolism. They also provide insights into the development of LD and the rescue of the disease by the catalytically inactive phosphatase.
Assuntos
Doença de Lafora , Proteínas Tirosina Fosfatases não Receptoras , Ubiquitina-Proteína Ligases , Doença de Lafora/metabolismo , Doença de Lafora/genética , Doença de Lafora/patologia , Animais , Camundongos , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , Proteínas Tirosina Fosfatases não Receptoras/metabolismo , Proteínas Tirosina Fosfatases não Receptoras/genética , Humanos , Fosfatases de Especificidade Dupla/metabolismo , Fosfatases de Especificidade Dupla/genética , Modelos Animais de Doenças , Glicogênio/metabolismo , Glicogênio/genéticaRESUMO
Inhibition of K-RAS effectors like B-RAF or MEK1/2 is accompanied by treatment resistance in cancer patients via re-activation of PI3K and Wnt signaling. We hypothesized that myotubularin-related-protein-7 (MTMR7), which inhibits PI3K and ERK1/2 signaling downstream of RAS, directly targets RAS and thereby prevents resistance. Using cell and structural biology combined with animal studies, we show that MTMR7 binds and inhibits RAS at cellular membranes. Overexpression of MTMR7 reduced RAS GTPase activities and protein levels, ERK1/2 phosphorylation, c-FOS transcription and cancer cell proliferation in vitro. We located the RAS-inhibitory activity of MTMR7 to its charged coiled coil (CC) region and demonstrate direct interaction with the gastrointestinal cancer-relevant K-RASG12V mutant, favouring its GDP-bound state. In mouse models of gastric and intestinal cancer, a cell-permeable MTMR7-CC mimicry peptide decreased tumour growth, Ki67 proliferation index and ERK1/2 nuclear positivity. Thus, MTMR7 mimicry peptide(s) could provide a novel strategy for targeting mutant K-RAS in cancers.
Assuntos
Neoplasias , Proteínas Tirosina Fosfatases não Receptoras , Animais , Humanos , Camundongos , Peptídeos , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Tirosina Fosfatases não Receptoras/genética , Proteínas Tirosina Fosfatases não Receptoras/metabolismo , Transdução de SinaisRESUMO
Lafora disease is a rare and fatal form of progressive myoclonic epilepsy with onset during early adolescence. The disease is caused by mutations in EPM2A, encoding laforin, or EPM2B, encoding malin. Both proteins have functions that affect glycogen metabolism, including glycogen dephosphorylation by laforin and ubiquitination of enzymes involved in glycogen metabolism by malin. Lack of function of laforin or malin results in the accumulation of polyglucosan that forms Lafora bodies in the central nervous system and other tissues. Enzyme replacement therapy through intravenous administration of alglucosidase alfa (Myozyme®) has shown beneficial effects removing polyglucosan aggregates in Pompe disease. We evaluated the effectiveness of intracerebroventricular administration of alglucosidase alfa in the Epm2a-/- knock-out and Epm2aR240X knock-in mouse models of Lafora disease. Seven days after a single intracerebroventricular injection of alglucosidase alfa in 12-month-old Epm2a-/- and Epm2aR240X mice, the number of Lafora bodies was not reduced. Additionally, a prolonged infusion of alglucosidase alfa for 2 or 4 weeks in 6- and 9-month-old Epm2a-/- mice did not result in a reduction in the number of LBs or the amount of glycogen in the brain. These findings hold particular significance in guiding a rational approach to the utilization of novel therapies in Lafora disease.
Assuntos
Doença de Lafora , alfa-Glucosidases , Camundongos , Animais , Doença de Lafora/tratamento farmacológico , Doença de Lafora/genética , Camundongos Knockout , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Glicogênio/metabolismo , Proteínas Tirosina Fosfatases não Receptoras/genéticaRESUMO
The protozoan parasite Leishmania donovani resides within mammalian macrophages and alters its antigen-presenting functions to negatively regulate host-protective T cell responses. This negative regulation of human T cell responses in vitro is attributed to myotubularin-related protein-6 (MTMR6), an ion channel-associated phosphatase. As mouse and human MTMR6 share homology, we studied whether MTMR6 silencing by lentivirally expressed MTMR6shRNA (Lv-MTMR6shRNA) reduced Leishmania growth in macrophages and whether MTMR6 silencing in Leishmania-susceptible BALB/c mice reduced the infection and reinstated host-protective T cell functions. MTMR6 silencing reduced amastigote count and IL-10 production, increased IL-12 expression and, induced IFN-γ-secreting T cells with anti-leishmanial activity in macrophage-T cell co-cultures. Lv-MTMR6shRNA reduced the infection, accompanied by increased IFN-γ expression, in susceptible BALB/c mice. Delays in Lv-MTMR6shRNA treatment by 7 days post-infection significantly reduced the infection suggesting MTMR6 as a plausible therapeutic target. Priming of BALB/c mice with avirulent parasites and Lv-MTMR6shRNA reduced parasite burden in challenge infection. These results indicate that MTMR6 is the first receptor-regulated ion channel-associated phosphatase regulating anti-leishmanial immune responses.
Assuntos
Leishmania donovani , Leishmaniose Visceral , Leishmaniose , Camundongos , Humanos , Animais , Proteínas Tirosina Fosfatases não Receptoras/genética , Camundongos Endogâmicos BALB C , Canais Iônicos , MamíferosRESUMO
Lafora disease (LD) is a life-threatening autosomal recessive and progressive neurodegenerative disorder that primarily affects adolescents, resulting in mortality within a decade of onset. The symptoms of LD include epileptic seizures, ataxia, dementia, and psychosis. The underlying pathology involves the presence of abnormal glycogen inclusions in neurons and other tissues, which may contribute to neurodegeneration. LD is caused by loss-of-function mutations in either the EPM2A gene or the NHLRC1 gene. These two genes, respectively, code for laforin phosphatase and malin ubiquitin ligase, and are thought to function, as a functional complex, in diverse cellular pathways. One of the major pathways affected in LD is glycogen metabolism; defects here lead to abnormally higher levels of glycogen and its hyperphosphorylation and aggregation, resulting in the formation of Lafora inclusion bodies. Currently, there is no effective therapy for LD. Studies, particularly from animal models, provide distinct insights into the fundamental mechanisms of diseases and potential avenues for therapeutic interventions. The purpose of this review is to present a comprehensive overview of our current knowledge regarding the disease, its genetics, the animal models that have been developed, and the therapeutic strategies that are being developed based on an understanding of the disease mechanism.
Assuntos
Doença de Lafora , Animais , Doença de Lafora/diagnóstico , Doença de Lafora/genética , Doença de Lafora/terapia , Proteínas Tirosina Fosfatases não Receptoras/genética , Neurônios/metabolismo , Mutação , Glicogênio/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismoRESUMO
BACKGROUND: Highly upregulated in liver cancer (HULC) is one of the LncRNAs that was documented to enhance cancer progression, and its downregulation is associated with cell cycle arrest and apoptosis. Myotubularin-related protein 3 (MTMR3) is required for autophagy, and many studies consider MTMR3 to be a negative regulator of autophagy processes. However, nothing is understood about how they regulate breast cancer. MATERIAL AND METHODS: This case-control study included 245 patients (Group A: 85 early BC Group B: 40 metastatic BC cases, Group C: 40 fibroadenoma cases; and Group D: 80 age matched healthy control subjects. TaqMan Real-time PCR was used to analyse rs7158663 and rs12537. MTMR3 and HULC gene expression levels were measured using RT-PCR. RESULT: Breast cancer patients exhibited elevated serum MTMR3 and HULC compared to fibroadenomas and control cases. The MTMR3 rs12537 "T/T" genotype was highly expressed in cases of breast cancer (early and metastatic) compared to controls (risk genotype). On the other hand, the HULC rs7158663 genotypes were not statistically associated with breast cancer. However, when compared to the control, the C/C genotype of the HULC gene is higher in the case.MTMR3 gene expression was higher in the T/T genotype compared to both the C/C and C/T genotypes, while HULC gene expression was lower in the A/C genotype compared to both the A/A and C/C genotypes. Positive correlation between MTMR3 and HULC. MTMR3 and ALT, as well as HULC and alkaline phosphatase, both showed a statistically significant positive correlation. CONCLUSION: Our findings reveal that MTMR3 and HULC serum expression and their SNPs (HULC rs7763881, MTMR3 rs12537) are associated with a higher risk for the development of breast cancer in the Egyptian population.
Assuntos
Neoplasias da Mama , Neoplasias Hepáticas , RNA Longo não Codificante , Feminino , Humanos , Neoplasias da Mama/genética , Estudos de Casos e Controles , Egito , Genótipo , Neoplasias Hepáticas/genética , Proteínas Tirosina Fosfatases não Receptoras/genética , RNA Longo não Codificante/genéticaRESUMO
Myotubular myopathy is a rare disease of genetic origin characterized by significant muscle weakness leading to respiratory disorders and for which no treatment exists today. In this paper, we show that inhibition of the activity of the enzyme PI3KC2ß prevents the development of this myopathy in a mouse model of the disease, thus identifying a therapeutic target to treat myotubular myopathy in humans.
Title: Une cible thérapeutique prometteuse dans la myopathie myotubulaire. Abstract: La myopathie myotubulaire est une maladie rare d'origine génétique caractérisée par une importante faiblesse musculaire entraînant des troubles respiratoires et pour laquelle aucun traitement n'existe aujourd'hui. Dans cet article, nous montrons que l'inhibition de l'activité de l'enzyme PI3KC2ß prévient le développement de cette myopathie dans un modèle murin de la maladie, identifiant ainsi une cible thérapeutique pour traiter la myopathie myotubulaire chez l'homme.
Assuntos
Miopatias Congênitas Estruturais , Animais , Camundongos , Modelos Animais de Doenças , Miopatias Congênitas Estruturais/genética , Miopatias Congênitas Estruturais/terapia , Proteínas Tirosina Fosfatases não Receptoras/genéticaRESUMO
Polyhydramnios can be caused by genetic defects at times. However, to establish an accurate diagnosis and provide a precise prenatal consultation in a given case is still a great challenge toward obstetricians. To uncover the genetic cause of polyhydramnios in the two consecutive pregnancies, we performed whole-exome sequencing of DNA for the second suffering fetuses, their parents, and targeted sanger sequencing of other members of this family. We discovered a hemizygous truncating variant in MTM1 gene, c.438_439 del (p. H146Q fs*10) in this Chinese family. In the light of the molecular discoveries, the fetus's clinical phenotype was considered to be a good fit for X-linked myotubular myopathy (XLMTM). There is no related research to the prenatal manifestations of MTM1-related XLMTM among Chinese population, and this is the first one to present. Though the etiology of polyhydramnios is complicated, WES may provide us with a creative avenue in prenatal diagnosis.
Assuntos
Miopatias Congênitas Estruturais , Poli-Hidrâmnios , Gravidez , Feminino , Humanos , Sequenciamento do Exoma , Poli-Hidrâmnios/diagnóstico por imagem , Poli-Hidrâmnios/genética , Proteínas Tirosina Fosfatases não Receptoras/genética , Mutação , Miopatias Congênitas Estruturais/diagnóstico , Miopatias Congênitas Estruturais/genética , Miopatias Congênitas Estruturais/patologiaRESUMO
Childhood dyslipidaemia is associated with the occurrence of cardiovascular diseases in adulthood, so evaluating whether an individual has a genetic predisposition to this pathology is of great importance for early action of prevention and treatment. This study aimed to evaluate the association between the FTO (rs9939609), MC4R (rs17782313) and MTMR9 (rs2293855) polymorphisms, the obesity-related genetic risk score and atherogenic risk in Brazilian children. This is a cross-sectional study conducted in 544 children aged 4-9 years in the city of Viçosa, Minas Gerais state, Brazil. The single nucleotide polymorphisms rs9939609, rs17782313 and rs2293855, were identified by the system TaqMan SNP genotyping and the obesity-related genetic risk score was determined. The lipid profile (serum total cholesterol [TC], high density lipoprotein [HDL] cholesterol, low density lipoprotein [LDL] cholesterol, triglycerides) was analysed and the atherogenic indices (Castelli I and II indices), atherogenic coefficient (AC), lipoprotein combined index (LCI) and plasma atherogenic index (PAI) were calculated. A semi-structured questionnaire was applied, obtaining data on the sociodemographic, economic and lifestyle characteristics of the children. Weight and height measurements were performed in all children, and body composition was evaluated by Dual-Energy X-ray Absorptiometry (DXA). 55.5% of the sample had dyslipidaemia, while 28.5% of the sample had at least one polymorphism and 2.2% had three polymorphisms. Children with the AG/AA genotypes in the rs2293855 polymorphism had lower HDL cholesterol levels and higher TC/HDL cholesterol, LDL/HDL cholesterol ratios and AC. Those with one or more polymorphisms (rs9939609, rs17782313 and rs2293855) in the genetic risk score had lower HDL cholesterol levels and higher TC/HDL cholesterol ratios, AC, LCI and PAI. In conclusion, the risk allele of the rs2293855 polymorphism and a higher obesity-related genetic risk score were positively associated with higher atherogenic risk in Brazilian children.