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1.
Sci Signal ; 17(817): eadg4422, 2024 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-38166031

RESUMO

Thousand-and-one-amino acid kinase 3 (TAOK3) is a serine and threonine kinase that belongs to the STE-20 family of kinases. Its absence reduces T cell receptor (TCR) signaling and increases the interaction of the tyrosine phosphatase SHP-1, a major negative regulator of proximal TCR signaling, with the kinase LCK, a component of the core TCR signaling complex. Here, we used mouse models and human cell lines to investigate the mechanism by which TAOK3 limits the interaction of SHP-1 with LCK. The loss of TAOK3 decreased the survival of naïve CD4+ T cells by dampening the transmission of tonic and ligand-dependent TCR signaling. In mouse T cells, Taok3 promoted the secretion of interleukin-2 (IL-2) in response to TCR activation in a manner that depended on Taok3 gene dosage and on Taok3 kinase activity. TCR desensitization in Taok3-/- T cells was caused by an increased abundance of Shp-1, and pharmacological inhibition of Shp-1 rescued the activation potential of these T cells. TAOK3 phosphorylated threonine-394 in the phosphatase domain of SHP-1, which promoted its ubiquitylation and proteasomal degradation. The loss of TAOK3 had no effect on the abundance of SHP-2, which lacks a residue corresponding to SHP-1 threonine-394. Modulation of SHP-1 abundance by TAOK3 thus serves as a rheostat for TCR signaling and determines the activation threshold of T lymphocytes.


Assuntos
Proteínas Serina-Treonina Quinases , Receptores de Antígenos de Linfócitos T , Linfócitos T , Animais , Humanos , Camundongos , Proteína Tirosina Quinase p56(lck) Linfócito-Específica , Fosforilação , Proteínas Serina-Treonina Quinases/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 11/genética , Proteína Tirosina Fosfatase não Receptora Tipo 11/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 6/genética , Proteína Tirosina Fosfatase não Receptora Tipo 6/metabolismo , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/metabolismo , Linfócitos T/metabolismo , Treonina/metabolismo
2.
J Chin Med Assoc ; 87(1): 12-16, 2024 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-38016117

RESUMO

A maternal inheritance disorder called Leber's hereditary optic neuropathy (LHON) is the most common primary mitochondrial deoxyribonucleic acid (DNA) disorder. In most studies, there are more male patients than female patients, which contradicts the usual pattern in mitochondrial hereditary diseases. This suggests that nuclear DNA (nDNA) may influence the degeneration of retinal ganglion cells (RGCs) in LHON. The primary cause of this is dysfunction in complex I of the electron transport chain, leading to ineffective adenosine triphosphate (ATP) production. In addition to MT-ND4 or MT-ND1 mutations, genes such as PRICKLE3 , YARS2 , and DNAJC30 , which come from nDNA, also play a role in LHON. These three genes affect the electron chain transport differently. PRICKLE3 interacts with ATP synthase (complex V) at Xp11.23, while YARS2 is a tyrosyl-tRNA synthetase 2 involved in mitochondria . DNAJC30 mutations result in autosomal recessive LHON (arLHON). Understanding how genes impact the disease is crucial for developing new treatments. Idebenone has been approved for treating LHON and has shown safety and efficacy in clinical trials. Mesenchymal stem cell-based therapy has also emerged as a potential treatment for LHON by transferring mitochondria into target cells. Gene therapy research focuses on specific gene mutations, and the wild-type ND4 gene target in the adeno-associated viruses (AAV) vector has shown promise in clinical trials as a potential treatment for LHON.


Assuntos
Atrofia Óptica Hereditária de Leber , Humanos , Masculino , Feminino , Atrofia Óptica Hereditária de Leber/terapia , Atrofia Óptica Hereditária de Leber/tratamento farmacológico , DNA Mitocondrial/genética , Mitocôndrias , Mutação , Trifosfato de Adenosina/uso terapêutico
3.
J Chin Med Assoc ; 86(6): 539-541, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-37027535

RESUMO

Optic neuropathies were estimated to affect 115 in 100,000 population in 2018. Leber's Hereditary Optic Neuropathy (LHON) as one of such optic neuropathy diseases that was first identified in 1871 and can be defined as a hereditary mitochondrial disease. LHON is associated with three mtDNA point mutations which are G11778A, T14484, and G3460A that affect the NADH dehydrogenase subunits of 4, 6, and 1, respectively. However, in most cases, only one point mutation is involved. Generally, in manifestation of the disease, there are no symptoms until the terminal dysfunction in the optic nerve is observed. Due to the mutations, nicotinamide adenine dinucleotide (NADH) dehydrogenase or complex I is absent and thus ATP production is stopped. This further causes the generation of reactive oxygen species and retina ganglion cells apoptosis. Aside from the mutations, there are several environmental factors such as smoking and alcohol consumption that can be pointed out as the risk factors of LHON. Nowadays, gene therapy has been intensively studied for LHON treatment. Disease models using human induced pluripotent stem cells (hiPSCs) have been utilized for LHON research.


Assuntos
Células-Tronco Pluripotentes Induzidas , Atrofia Óptica Hereditária de Leber , Humanos , Atrofia Óptica Hereditária de Leber/genética , Atrofia Óptica Hereditária de Leber/terapia , Atrofia Óptica Hereditária de Leber/diagnóstico , Mutação , Mutação Puntual , DNA Mitocondrial/genética
4.
Scand J Gastroenterol ; 58(1): 61-69, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35830511

RESUMO

BACKGROUND: The characteristics and prognosis of cryptogenic hepatocellular carcinoma (HCC) remain unclear. The albumin-bilirubin (ALBI) grade and its updated version, the easy ALBI (EZ-ALBI) grade, are important prognostic predictors for HCC. We aimed to investigate the long-term survival of patients with cryptogenic HCC and the prognostic role of ALBI and EZ-ALBI grade in these patients. METHODS: A prospective cohort of 2,937 HCC patients with viral or cryptogenic etiology were retrospectively analyzed. The multivariate Cox model was used to determine prognostic predictors. RESULTS: Cryptogenic HCC patients were often older and diabetic, had lower serum ɑ-fetoprotein (AFP) levels, larger tumor burden, poor performance status, advanced cancer stage, and received non-curative treatments compared with hepatitis B or C-related HCC. The Cox analysis showed that age > 65 years, serum AFP > 400 ng/mL, presence of vascular invasion or distant metastasis, presence of ascites, performance status 2-4, ALBI grade 2 and 3, EZ-ALBI grade 2 and 3, and non-curative treatment, were independent predictors of decreased survival in cryptogenic HCC (p < .001). Significant survival differences were found across ALBI grade and EZ-ALBI grade in cryptogenic HCC and subgroup patients receiving curative or non-curative treatments. The Cancer of Liver Italian Program was the best staging system for patients with cryptogenic HCC. CONCLUSIONS: Patients with cryptogenic HCC have a larger tumor burden and advanced cancer stage at disease presentation compared with those with viral HCC. The ALBI and EZ-ALBI score are robust models to evaluate liver functional reserve for these patients independent of treatment modality.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Idoso , Prognóstico , Bilirrubina , alfa-Fetoproteínas , Estudos Retrospectivos , Estudos Prospectivos , Albumina Sérica/análise
5.
J Chin Med Assoc ; 85(4): 409-413, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-35383703

RESUMO

Lung carcinoma (LC) is the third most common cancer diagnosis and accounted for the most cancer-related mortality worldwide in 2018. Based on the type of cells from which it originates, LC is commonly classified into non-small cell lung cancers (NSCLC) and small cell lung cancers (SCLC). NSCLC account for the majority of LC and can be further categories into adenocarcinoma, large cell carcinoma, and squamous cell carcinoma. Accurate classification of LC is critical for its adequate treatment and therapeutic outcome. Since NSCLC express more epidermal growth factor receptor (EGFR) with activation mutations, targeted therapy EGFR-tyrosine kinase inhibitors (TKIs) have been considered as primary option of NSCLC patients with activation EGFR mutation. In this review, we present the genetic alterations, reported mutations in EGFR, and TKIs treatment in NSCLC patients with an emphasis on the downstream signaling pathways in NSCLC progression. Among the signaling pathways identified, mitogen activation protein kinase (MAPK), known also as extracellular signal-regulated protein kinase (Erk) pathway, is the most investigated among the related pathways. EGFR activation leads to the autophosphorylation of its kinase domain and subsequent activation of Ras, phosphorylation of Raf and MEK1/2, and the activation of ERK1/2. Phosphatidylinositol 3-kinase (PI3K)/Akt is another signal pathway that regulates cell cycle and has been linked to NSCLC progression. Currently, three generations of EGFR TKIs have been developed as a first-line treatment of NSCLC patients with EGFR activation and mutation in which these treatment options will be further discussed in this review. The Supplementary Appendix for this article is available at http://links.lww.com/JCMA/A138.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Resistencia a Medicamentos Antineoplásicos/genética , Fator de Crescimento Epidérmico , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Mutação , Fosfatidilinositol 3-Quinases , Inibidores de Proteínas Quinases/uso terapêutico , Transdução de Sinais
6.
J Chin Med Assoc ; 85(6): 667-671, 2022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35385421

RESUMO

The cellular process responsible for the degradation of cytosolic proteins and subcellular organelles in lysosomes was termed "autophagy." This process occurs at a basal level in most tissues as part of tissue homeostasis that redounds to the regular turnover of components inside cytoplasm. The breakthrough in the autophagy field is the identification of key players in the autophagy pathway, compounded under the name "autophagy-related genes" (ATG) encoding for autophagy effector proteins. Generally, the function of autophagy can be classified into two divisions: intracellular clearance of defective macromolecules and organelles and generation of degradation products. Therapeutic strategies using stem cell-based approach come as a promising therapy and develop rapidly recently as stem cells have high self-renewability and differentiation capability as known as mesenchymal stem cells (MSCs). They are defined as adherent fibroblast-like population with the abilities to self-renew and multi-lineage differentiate into osteogenic, adipogenic, and chondrogenic lineage cells. To date, they are the most extensively applied adult stem cells in clinical trials. The properties of MSCs, such as immunomodulation, neuroprotection, and tissue repair pertaining to cell differentiation, processes to replace lost, or damaged cells, for aiding cell repair and revival. Autophagy has been viewed as a remarkable mechanism for maintaining homeostasis, ensuring the adequate function and survival of long-lived stem cells. In addition, authophagy also plays a remarkable role in protecting stem cells against cellular stress when the stem cell regenerative capacity is harmed in aging and cellular degeneration. Understanding the under-explored mechanisms of MSC actions and expanding the spectrum of their clinical applications may improve the utility of the MSC-based therapeutic approach in the future.


Assuntos
Células-Tronco Mesenquimais , Células-Tronco , Autofagia , Diferenciação Celular , Osteogênese
7.
J Chin Med Assoc ; 85(2): 198-203, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-35175243

RESUMO

BACKGROUND: Trigeminal neuralgia (TN) is a disease characterized by recurring, short-lived, electric shock-like pain experienced on one side of the face. Microvascular decompression (MVD) is one of the most effective surgical interventions for resolving TN caused by neurovascular compression. This study aimed to determine the predictive and prognostic factors of surgical outcomes. METHODS: This retrospective cohort study enrolled patients diagnosed with TN who underwent MVD at our hospital during 2013-2019. The demographic information, pain character, peri-operative Barrow Neurological Institute (BNI) scale, medication, operative finding were recorded. And the outcome was Outcomes were divided into drug-free and drug-dependent group. Predisposing factors for each outcome were analyzed by one-way analysis of variance, followed by a Mann-Whitney U test or Kruskal-Wallis test. RESULTS: A total of 104 consecutive patients received MVD to treat TN, and 88 patients were enrolled in this study. The overall postoperative drug-free outcome was 72.7%. A significant difference in drug-free outcomes was observed for patients with typical TN (80.8%) compared with patients with atypical TN (33.33%, p = 0001). When severe venous compression was encountered during MVD, the drug-free outcome fell to 50% (10/20, p = 0.009). The Mann-Whitney U test indicated typical TN as a positive predictive factor of a drug-free outcome, whereas severe venous compression was a negative predictive factor. The patients with preoperative BNI score of 4 had better improvement than others (p = 0.045). Age, onset duration, and arterial loop had no specific difference in this study. CONCLUSION: In our study, atypical TN and severe venous compression were associated with poor outcomes. Regrouping atypical TN into precise diagnosis represents an immediate priority according to our result. The preoperative BNI score could be used as an effective predictive tool for the outcome of MVD surgery.


Assuntos
Cirurgia de Descompressão Microvascular , Avaliação de Resultados em Cuidados de Saúde , Neuralgia do Trigêmeo/fisiopatologia , Neuralgia do Trigêmeo/cirurgia , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
8.
J Chin Med Assoc ; 84(11): 1054-1059, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34747902

RESUMO

BACKGROUND: Most reproductive system studies suggest the protective effects of vitamin D, but vitamin D deficiency and insufficiency are growing global health issues. The present study investigates the association between vitamin D deficiency/insufficiency and gynecologic diseases to identify illness risks at different serum vitamin D levels in Taiwan. METHODS: A total of 7699 female adults aged ≥20 years with results for both serum vitamin D and gynecologic-associated diseases were drawn from the Taiwan MJ cohort. We analyzed the correlation between serum vitamin D levels and results from reproductive system evaluations, including history of dysmenorrhea, results of Pap smear, high-risk human papillomavirus (HPV) infection of the cervix, mammography, and ultrasound of breast and pelvis. RESULTS: Over 80% of participants showed vitamin D deficiency/insufficiency. Participants with abnormal Pap smear results, high-risk HPV infection, and history of dysmenorrhea showed significantly lower levels of serum vitamin D (p < 0.001-0.05). Serum vitamin D deficiency was significantly associated with positive high-risk HPV infection of the cervix (p < 0.05) and dysmenorrhea (p < 0.001). After controlling for age as a confounding variable for each gynecologic disease, level of serum vitamin D was significantly associated with abnormal breast ultrasound (odds ratio = 0.724) and uterus ultrasound (odds ratio = 0.673 - 0.8), and dysmenorrhea (odds ratio = 0.829). CONCLUSION: Associations were found between vitamin D deficiency and endometriosis, uterine myoma, dysmenorrhea, abnormal Pap smear results, and high-risk HPV infection of the cervix. Therefore, vitamin D supplements may present a cost-effective benefit for the prevention and treatment of gynecologic diseases, and thus reduction of healthcare expenditures.


Assuntos
Doenças dos Genitais Femininos/fisiopatologia , Deficiência de Vitamina D/complicações , Adolescente , Feminino , Humanos , Medição de Risco , Taiwan , Adulto Jovem
9.
J Chin Med Assoc ; 84(12): 1100-1108, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34596084

RESUMO

BACKGROUND: Hepatocellular carcinoma (HCC) ranks many tasks in clinical oncology due to possibly developing a general tumor in men and, usually lead to malignant to death within years. Researches had reported about major factors for being HCC was male sex and HCC associated with cirrhosis in childhood was found more common in males than females. In certain mouse strains as studied, breeding with testosterone significantly increases the development of HCC. Furthermore, castration of male mice diminished the frequency of the development of liver tumors. Meanwhile male hepatitis B virus transgenic mice have a greater occurrence of HCC than females. METHODS: We apply degenerate priming PCR to observe the expression of various steroid receptors in livers. Yeast-two hybrid screening to search a novel RNA fragment helps to find a new full-length gene by RACE experiment. RT-PCR is applied to detect various expressions in tissues and cell lines. In situ hybridization detects DNA in Chromosome mapping. GFP-constructs transfection proves the gene localization in cells. Immunoprecipitation pulldown assay verifies protein interaction. Gene transfection followed with luciferase assay demonstrates the interaction of genes within cellular signaling. Genomic alignment analysis for observing sequences data perform from NCBI database website (http://www.ncbi.nim.nih.gov/genebank/). RESULTS: The androgen receptor (AR) expression level is found at the highest level among the steroid receptors families detected in liver tumors. By yeast-two hybrid screening, we cloned an Androgen Receptor Complex Associated Protein (ARCAP), of 95 Kd in molecular weight and its cDNA. ARCAP locates at Chromosome 1. Our findings indicate ARCAP is highly expressed in hepatoma cell lines and liver tumors and their adjacent tumors as observed. Yeast two-hybrid assay and in vitro immunoprecipitation assays demonstrated an interaction between AR and ARCAP. CONCLUSION: We aim to search for different types and levels of steroid receptors expressed within human HCCs and in the adjacent liver tissues. To verify possible molecular mechanisms by which AR might affect hepatoma cells, we had characterized a novel protein ARCAP which functions as a coregulator to interact with AR within liver. The ligand-dependent AR with its cofactor, ARCAP, can induce a signal cascade by transactivation.


Assuntos
Carcinoma Hepatocelular/fisiopatologia , Neoplasias Hepáticas , Fígado/metabolismo , Fígado/fisiopatologia , Receptores Androgênicos/metabolismo , Animais , Vírus da Hepatite B , Masculino , Camundongos , Receptores Androgênicos/genética
10.
J Chin Med Assoc ; 84(11): 987-992, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34524226

RESUMO

Oral cancers are the seventh most common cancer globally. While progresses in oral cancer treatment have been made, not all patients respond to these therapies in the same way. To overcome this difficulty, numerous studies have been devoted to identifying biomarkers, which enable early identification of patients who may benefit from a particular treatment modality or at risk for poor prognosis. Biomarkers are protein molecules, gene expression, DNA variants, or metabolites that are derived from tumors, adjacent normal tissue or bodily fluids, which can be acquired before treatment and during follow-up, thus extending their use to the evaluation of cancer progression and prediction of treatment outcome. In this review, we employed a basic significance level (<0.05) as the minimal requirement for candidate biomarkers. Effect sizes of the biomarkers in terms of odds ratio, hazard ratio, and area under the receiver operating characteristic curves were subsequently used to evaluate the potential of their clinical use. We identified the CCND1 from the tumor, human papillomavirus, HSP70, and IL-17 from the peripheral blood, and high density of CD45RO+ tumor-infiltrating lymphocytes as the clinically relevant biomarkers for oral cancers.


Assuntos
Biomarcadores Tumorais , Neoplasias Bucais/diagnóstico , Humanos , Neoplasias Bucais/genética , Neoplasias Bucais/fisiopatologia , Taiwan
11.
J Cell Biol ; 216(12): 4313-4330, 2017 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-29089377

RESUMO

Throughout life, stem cells in the ventricular-subventricular zone generate neuroblasts that migrate via the rostral migratory stream (RMS) to the olfactory bulb, where they differentiate into local interneurons. Although progress has been made toward identifying extracellular factors that guide the migration of these cells, little is known about the intracellular mechanisms that govern the dynamic reshaping of the neuroblasts' morphology required for their migration along the RMS. In this study, we identify DOCK7, a member of the DOCK180-family, as a molecule essential for tangential neuroblast migration in the postnatal mouse forebrain. DOCK7 regulates the migration of these cells by controlling both leading process (LP) extension and somal translocation via distinct pathways. It controls LP stability/growth via a Rac-dependent pathway, likely by modulating microtubule networks while also regulating F-actin remodeling at the cell rear to promote somal translocation via a previously unrecognized myosin phosphatase-RhoA-interacting protein-dependent pathway. The coordinated action of both pathways is required to ensure efficient neuroblast migration along the RMS.


Assuntos
Fatores de Troca do Nucleotídeo Guanina/genética , Fosfatase de Miosina-de-Cadeia-Leve/genética , Neurônios/metabolismo , Prosencéfalo/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas rho de Ligação ao GTP/genética , Actinas/genética , Actinas/metabolismo , Animais , Animais Recém-Nascidos , Diferenciação Celular , Linhagem Celular Tumoral , Movimento Celular , Embrião de Mamíferos , Proteínas Ativadoras de GTPase , Regulação da Expressão Gênica no Desenvolvimento , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Células HEK293 , Células HeLa , Humanos , Camundongos , Microtúbulos/metabolismo , Microtúbulos/ultraestrutura , Fosfatase de Miosina-de-Cadeia-Leve/metabolismo , Neurônios/ultraestrutura , Cultura Primária de Células , Prosencéfalo/citologia , Prosencéfalo/crescimento & desenvolvimento , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Proteínas rho de Ligação ao GTP/metabolismo , Proteína rhoA de Ligação ao GTP
12.
J Cell Biochem ; 115(11): 1888-99, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24905183

RESUMO

Honokiol is a small biphenolic compound, which exerts antitumor activities; however, the precise mechanism of honokiol-induced apoptosis in the human colorectal cancer cells remains unclear. Here, we show that survivin and p53 display the opposite role on the regulation of honokiol-induced apoptosis in the human colorectal cancer cells. Honokiol induced the cell death and apoptosis in various colorectal cancer cell lines. Moreover, honokiol elicited the extrinsic death receptor pathway of DR5 and caspase 8 and the intrinsic pathway of caspase 9. The common intrinsic and extrinsic downstream targets of activated caspase 3 and PARP protein cleavage were induced by honokiol. Interestingly, honokiol reduced anti-apoptotic survivin protein and gene expression. Transfection with a green fluorescent protein (GFP)-survivin-expressed vector increased the colorectal cancer cell viability and resisted the honokiol-induced apoptosis. Meantime, honokiol increased total p53 and the phosphorylated p53 proteins at Ser15 and Ser46. The p53-wild type colorectal cancer cells were exhibited greater cytotoxicity, apoptosis and survivin reduction than the p53-null cancer cells after treatment with honokiol. Together, these findings demonstrate that the existence of survivin and p53 can modulate the honokiol-induced apoptosis in the human colorectal cancer cells.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Compostos de Bifenilo/farmacologia , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Proteínas Inibidoras de Apoptose/metabolismo , Lignanas/farmacologia , Apoptose , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/genética , Resistencia a Medicamentos Antineoplásicos , Células HCT116 , Humanos , Proteínas Inibidoras de Apoptose/genética , Transdução de Sinais/efeitos dos fármacos , Survivina , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
13.
Cell Rep ; 6(2): 254-63, 2014 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-24440718

RESUMO

Chandelier cells (ChCs), typified by their unique axonal morphology, are the most distinct interneurons present in cortical circuits. Via their distinctive axonal terminals, called cartridges, these cells selectively target the axon initial segment of pyramidal cells and control action potential initiation; however, the mechanisms that govern the characteristic ChC axonal structure have remained elusive. Here, by employing an in utero electroporation-based method that enables genetic labeling and manipulation of ChCs in vivo, we identify DOCK7, a member of the DOCK180 family, as a molecule essential for ChC cartridge and bouton development. Furthermore, we present evidence that DOCK7 functions as a cytoplasmic activator of the schizophrenia-associated ErbB4 receptor tyrosine kinase and that DOCK7 modulates ErbB4 activity to control ChC cartridge and bouton development. Thus, our findings define DOCK7 and ErbB4 as key components of a pathway that controls the morphological differentiation of ChCs, with implications for the pathogenesis of schizophrenia.


Assuntos
Córtex Cerebral/crescimento & desenvolvimento , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Interneurônios/metabolismo , Terminações Pré-Sinápticas/metabolismo , Animais , Córtex Cerebral/citologia , Córtex Cerebral/metabolismo , Receptores ErbB/genética , Receptores ErbB/metabolismo , Proteínas Ativadoras de GTPase , Fatores de Troca do Nucleotídeo Guanina/genética , Camundongos , Receptor ErbB-4
14.
Structure ; 15(3): 377-89, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17355872

RESUMO

Sirtuins are NAD(+)-dependent protein deacetylases and are emerging as molecular targets for the development of pharmaceuticals to treat human metabolic and neurological diseases and cancer. To date, several sirtuin inhibitors and activators have been identified, but the structural mechanisms of how these compounds modulate sirtuin activity have not yet been determined. We identified suramin as a compound that binds to human SIRT5 and showed that it inhibits SIRT5 NAD(+)-dependent deacetylase activity with an IC(50) value of 22 microM. To provide insights into how sirtuin function is altered by inhibitors, we determined two crystal structures of SIRT5, one in complex with ADP-ribose, the other bound to suramin. Our structural studies provide a view of a synthetic inhibitory compound in a sirtuin active site revealing that suramin binds into the NAD(+), the product, and the substrate-binding site. Finally, our structures may enable the rational design of more potent inhibitors.


Assuntos
Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , NAD/fisiologia , Sirtuínas/antagonistas & inibidores , Sirtuínas/química , Suramina/química , Suramina/farmacologia , Sequência de Aminoácidos , Sítios de Ligação/efeitos dos fármacos , Cristalografia por Raios X , Inibidores Enzimáticos/metabolismo , Humanos , Dados de Sequência Molecular , NAD/química , Ligação Proteica/fisiologia , Sirtuínas/metabolismo , Relação Estrutura-Atividade , Suramina/metabolismo
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