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1.
Cell ; 160(1-2): 145-60, 2015 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-25594178

RESUMO

The epidermal growth factor receptor (EGFR) is upregulated in numerous human cancers. Inhibition of EGFR signaling induces autophagy in tumor cells. Here, we report an unanticipated role for the inactive EGFR in autophagy initiation. Inactive EGFR interacts with the oncoprotein LAPTM4B that is required for the endosomal accumulation of EGFR upon serum starvation. Inactive EGFR and LAPTM4B stabilize each other at endosomes and recruit the exocyst subcomplex containing Sec5. We show that inactive EGFR, LAPTM4B, and the Sec5 subcomplex are required for basal and starvation-induced autophagy. LAPTM4B and Sec5 promote EGFR association with the autophagy inhibitor Rubicon, which in turn disassociates Beclin 1 from Rubicon to initiate autophagy. Thus, the oncoprotein LAPTM4B facilitates the role of inactive EGFR in autophagy initiation. This pathway is positioned to control tumor metabolism and promote tumor cell survival upon serum deprivation or metabolic stress.


Assuntos
Autofagia , Receptores ErbB/metabolismo , Proteínas Reguladoras de Apoptose/metabolismo , Autofagia/efeitos dos fármacos , Proteínas Relacionadas à Autofagia , Proteína Beclina-1 , Linhagem Celular Tumoral , Endossomos/metabolismo , Receptores ErbB/antagonistas & inibidores , Cloridrato de Erlotinib , Gefitinibe , Células HEK293 , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas de Membrana/metabolismo , Proteínas Oncogênicas/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Quinazolinas/farmacologia , Proteínas de Transporte Vesicular/metabolismo
2.
Nature ; 567(7747): 262-266, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30842662

RESUMO

Cyclic GMP-AMP (cGAMP) synthase (cGAS) detects infections or tissue damage by binding to microbial or self DNA in the cytoplasm1. Upon binding DNA, cGAS produces cGAMP that binds to and activates the adaptor protein STING, which then activates the kinases IKK and TBK1 to induce interferons and other cytokines2-6. Here we report that STING also activates autophagy through a mechanism that is independent of TBK1 activation and interferon induction. Upon binding cGAMP, STING translocates to the endoplasmic reticulum-Golgi intermediate compartment (ERGIC) and the Golgi in a process that is dependent on the COP-II complex and ARF GTPases. STING-containing ERGIC serves as a membrane source for LC3 lipidation, which is a key step in autophagosome biogenesis. cGAMP induced LC3 lipidation through a pathway that is dependent on WIPI2 and ATG5 but independent of the ULK and VPS34-beclin kinase complexes. Furthermore, we show that cGAMP-induced autophagy is important for the clearance of DNA and viruses in the cytosol. Interestingly, STING from the sea anemone Nematostella vectensis induces autophagy but not interferons in response to stimulation by cGAMP, which suggests that induction of autophagy is a primordial function of the cGAS-STING pathway.


Assuntos
Autofagia , Proteínas de Membrana/metabolismo , Nucleotidiltransferases/metabolismo , Transdução de Sinais , Animais , Autofagossomos/metabolismo , Proteína 5 Relacionada à Autofagia/deficiência , Proteína 5 Relacionada à Autofagia/genética , Proteína 5 Relacionada à Autofagia/metabolismo , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/deficiência , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/genética , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/metabolismo , Proteína Beclina-1/deficiência , Proteína Beclina-1/genética , Proteína Beclina-1/metabolismo , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Classe III de Fosfatidilinositol 3-Quinases/metabolismo , Citosol/virologia , Vírus de DNA/genética , Vírus de DNA/metabolismo , DNA Viral/metabolismo , Retículo Endoplasmático/metabolismo , Evolução Molecular , Complexo de Golgi/metabolismo , Células HEK293 , Humanos , Interferons/biossíntese , Interferons/imunologia , Proteínas de Membrana/deficiência , Proteínas de Membrana/genética , Camundongos , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Nucleotídeos Cíclicos/imunologia , Nucleotídeos Cíclicos/metabolismo , Proteínas de Ligação a Fosfato , Proteínas Serina-Treonina Quinases/metabolismo , Transporte Proteico , Anêmonas-do-Mar , Proteínas de Transporte Vesicular/metabolismo
3.
Biochem Biophys Res Commun ; 726: 150274, 2024 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-38924882

RESUMO

Alzheimer's disease (AD) is a complex neurodegenerative condition with growing evidence implicating the gut microbiota in its pathogenesis. This study aimed to investigate the effects of NMN synbiotics, a combination of ß-nicotinamide mononucleotide (NMN), Lactobacillus plantarum, and lactulose, on the gut microbiota composition and metabolic profiles in APP/PS1 transgenic mice. Results demonstrated that NMN synbiotics led to a notable restructuring of the gut microbiota, with a decreased Firmicutes/Bacteroidetes ratio in the AD mice, suggesting a potential amelioration of gut dysbiosis. Alpha diversity indices indicated a reduction in microbial diversity following NMN synbiotics supplementation, while beta diversity analyses revealed a shift towards a more balanced microbial community structure. Functional predictions based on the 16S rRNA data highlighted alterations in metabolic pathways, particularly those related to amino acid and energy metabolism, which are crucial for neuronal health. The metabolomic analysis uncovered a significant impact of NMN synbiotics on the gut metabolome, with normalization of metabolic composition in AD mice. Differential metabolite functions were enriched in pathways associated with neurotransmitter synthesis and energy metabolism, pointing to the potential therapeutic effects of NMN synbiotics in modulating the gut-brain axis and synaptic function in AD. Immunohistochemical staining observed a significant reduction of amyloid plaques formed by Aß deposition in the brain of AD mice after NMN synbiotics intervention. The findings underscore the potential of using synbiotics to ameliorate the neurodegenerative processes associated with Alzheimer's disease, opening new avenues for therapeutic interventions.


Assuntos
Doença de Alzheimer , Precursor de Proteína beta-Amiloide , Modelos Animais de Doenças , Microbioma Gastrointestinal , Camundongos Transgênicos , Simbióticos , Animais , Doença de Alzheimer/metabolismo , Doença de Alzheimer/dietoterapia , Doença de Alzheimer/terapia , Doença de Alzheimer/microbiologia , Simbióticos/administração & dosagem , Camundongos , Precursor de Proteína beta-Amiloide/metabolismo , Precursor de Proteína beta-Amiloide/genética , Presenilina-1/metabolismo , Presenilina-1/genética , Mononucleotídeo de Nicotinamida/metabolismo , Masculino , Disbiose/metabolismo , Disbiose/microbiologia , Disbiose/dietoterapia , Disbiose/terapia
4.
Annu Rev Microbiol ; 72: 447-478, 2018 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-30200854

RESUMO

Microbial infections are recognized by the innate immune system through germline-encoded pattern recognition receptors (PRRs). As most microbial pathogens contain DNA and/or RNA during their life cycle, nucleic acid sensing has evolved as an essential strategy for host innate immune defense. Pathogen-derived nucleic acids with distinct features are recognized by specific host PRRs localized in endolysosomes and the cytosol. Activation of these PRRs triggers signaling cascades that culminate in the production of type I interferons and proinflammatory cytokines, leading to induction of an antimicrobial state, activation of adaptive immunity, and eventual clearance of the infection. Here, we review recent progress in innate immune recognition of nucleic acids upon microbial infection, including pathways involving endosomal Toll-like receptors, cytosolic RNA sensors, and cytosolic DNA sensors. We also discuss the mechanisms by which infectious microbes counteract host nucleic acid sensing to evade immune surveillance.


Assuntos
Doenças Transmissíveis/imunologia , Imunidade Inata , Ácidos Nucleicos/imunologia , Ácidos Nucleicos/metabolismo , Receptores de Reconhecimento de Padrão/metabolismo , Citocinas/metabolismo , Citosol/metabolismo , Endossomos/metabolismo , Interações Hospedeiro-Patógeno , Interferon Tipo I/metabolismo , Lisossomos/metabolismo , Transdução de Sinais
5.
Stem Cells ; 40(11): 1008-1019, 2022 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-35977539

RESUMO

p53 plays a pivotal role in maintaining the genomic stability of mouse embryonic stem cells (mESCs) through transcriptionally activating and repressing target genes. However, how p53 recognizes its repressed targets remains largely unknown. Herein, we demonstrate that Sall4 negatively regulates DNA damage induced apoptosis (DIA) of mESCs through mediating p53 recruitment to enhancers of ESC-associated genes repressed by p53 from promoters of p53-activated genes. Upon DNA damage, Sall4 is transcriptionally repressed by p53 and plays an anti-apoptotic role without altering p53 activation. Moreover, Sall4 is identified as a novel p53-interacting partner. Consistently, Sall4 exerts its anti-apoptotic function in a p53-dependent manner. Intriguingly, Sall4 depletion not only promotes the transcriptional activation of several p53-regulated pro-apoptotic genes but also compromises p53-mediated repression of ESC master transcription factors in response to DNA damage. Mechanistically, Sall4 balances p53-binding affinity between p53-activated and -repressed genes through tethering p53 to ESC enhancers. In light of our study, Sall4 may contribute to tumorigenesis by antagonizing p53-mediated apoptosis.


Assuntos
Proteínas de Ligação a DNA , Células-Tronco Embrionárias Murinas , Fatores de Transcrição , Proteína Supressora de Tumor p53 , Animais , Camundongos , Dano ao DNA/genética , Células-Tronco Embrionárias Murinas/metabolismo , Ligação Proteica , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo
6.
BMC Womens Health ; 23(1): 224, 2023 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-37138241

RESUMO

BACKGROUND: Female infertility is a major problem for women of reproductive-age worldwide. Oxidative stress and inflammation are involved in processes related to female infertility. Serum uric acid levels, an indicator of oxidative stress and inflammation, have rarely been reported to be associated with female infertility. This study aimed to investigate the relationship between serum uric acid levels and female infertility. METHODS: This cross-sectional study included women aged 18-44 years from the National Health and Nutrition Examination Survey (NHANES) between 2013 and 2018. All data were extracted from NHANES questionnaires and laboratory measurements. Weighted univariable and multivariable logistic regression analyses were utilized to explore the relationship between serum uric acid and female infertility. Stratified analyses were performed based on body mass index (BMI, < 25 kg/m2 and ≥ 25 kg/m2) and age (≤ 30 years and > 30 years). The odds ratio (OR) with 95% confidence interval (CI) was used to report associations. RESULTS: A total of 2,884 women were included, of which 352 (13.30%) had infertility. Women with high serum uric acid concentrations were related to higher odds of infertility (OR = 1.20, 95%CI: 1.03-1.39) after adjusting for confounders. Compared with serum uric acid concentrations ≤ 3.72 mg/dL, women with uric acid concentrations of 4.43-5.13 mg/dL (OR = 1.65, 95%CI: 1.02-2.67) and > 5.13 mg/dL (OR = 1.86, 95%CI: 1.10-3.13) were related to higher odds of infertility. Stratified analyses showed that high serum uric acid concentrations were associated with higher odds of infertility in women with a BMI < 25 kg/m2 (OR = 1.41, 95%CI: 1.04-1.93), but not in women with a BMI ≥ 25 kg/m2 (P = 0.056). In addition, high serum uric acid concentrations were associated with higher odds of infertility in women aged > 30 years (OR = 1.23, 95%CI: 1.04-1.45), but not in women aged ≤ 30 years (P = 0.556). CONCLUSION: Women with high serum uric acid concentrations were associated with higher odds of infertility, and this association may vary by BMI and age.


Assuntos
Infertilidade Feminina , Ácido Úrico , Humanos , Feminino , Inquéritos Nutricionais , Estudos Transversais , Inflamação
7.
Mol Med ; 28(1): 155, 2022 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-36514009

RESUMO

BACKGROUND: Exenatide is a stable analogue of glucagon-like peptide 1 that can reduce postprandial hyperglycemia and has been utilized as adjunctive therapy for type 1 diabetes mellitus (T1DM). The human umbilical cord is a rich source of MSCs, and human umbilical cord mesenchymal stem cells (hUCMSCs) also show potential to enhance insulin secretion. Here, we aimed to explore the effects of hUCMSCs carrying exenatide in T1DM and further identify the possible mechanisms involved. METHODS: hUCMSCs were isolated from human umbilical cord tissues, identified, and transduced with recombinant lentivirus carrying exenatide to obtain exenatide-carrying hUCMSCs (hUCMSCs@Ex-4). RESULTS: The results showed that hUCMSCs@Ex-4 restored the blood glucose levels and body weight of NOD mice, and repressed immune cell infiltration and islet tissue changes. Additionally, in T1DM mice, treatment with hUCMSCs@Ex-4 reduced the blood glucose levels and promoted repair of islet tissue damage. Moreover, hUCMSCs@Ex-4 attenuated renal tissue lesions in T1DM mice. Applying bioinformatic analysis, the effects of hUCMSCs@Ex-4 were suggested to correlate with decreased abundance of pro-inflammatory intestinal bacteria and increased abundance of anti-inflammatory intestinal bacteria. CONCLUSION: Overall, the study indicated that hUCMSCs carrying exenatide might improve beneficial intestinal microflora abundance and promote islet tissue damage repair, thereby alleviating T1DM.


Assuntos
Diabetes Mellitus Tipo 1 , Microbioma Gastrointestinal , Células-Tronco Mesenquimais , Humanos , Camundongos , Animais , Exenatida/farmacologia , Glicemia , Camundongos Endogâmicos NOD
8.
Small ; 18(28): e2202128, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35708218

RESUMO

Stepper motors and actuators are among the main constituents of control motion devices. They are complex multibody systems with rather large overall volume due to their multifunctional parts and elaborate technological assembly processes. Miniaturization of individual parts is still posing assembly problems. In this paper, a single-step lithography process to fabricate a micro-stepper engine with an accurate micrometric rotation axis and an overall sub-millimeter size is demonstrated. The device is based on the frictional contacts and chiral metamaterials to get rid of the dependence on the accuracy of parts. The functional aspects of fabricated samples are discussed for many rotation cycles and for different frictional surfaces.

9.
Mol Biol Rep ; 49(7): 6885-6898, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35182325

RESUMO

BACKGROUND: Cancer stem cells play important roles in the process of tumorigenesis. Our research group obtained cancer stem cell-like cells named Piwil2-iCSCs by reprogramming human preputial fibroblasts (FBs) with the PIWIL2 gene, but the mechanism of Piwil2-iCSCs is still unclear. METHODS: We sequenced the piRNAs, miRNAs and mRNAs of Piwil2-iCSCs and FBs, and analyzed the differences. Gene Ontology (GO) and, Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses and gene set enrichment analysis (GSEA) were performed on the differentially expressed (DE) mRNAs. In addition, we analyzed the variable shear events and fusion genes in the Piwil2-iCSCs. Target gene prediction and functional enrichment analysis were performed for the DE miRNAs. RESULTS: A total of 1119 DE mRNAs, 220 DE piRNAs, and 440 DE miRNAs were obtained between the Piwil2-iCSCs and FBs. Functional enrichment analysis showed that the genes with upregulated expression were mainly involved in DNA repair, mismatch repair, base excision repair, and nucleotide excision repair. Genes with downregulated expression were mainly involved in the TGF-ß receptor signaling pathway, senescence and autophagy in cancer. More frequent shear events occurred in Piwil2-iCSCs and FBs, especially in intron retention (IR) events. We also identified three fusion genes MCM3AP-C21orf58, LRRFIP2-CAV3 and TMEM184B-DMC1. Enrichment analysis of DE miRNAs showed that they were associated with apoptosis, the TGF-ß signaling pathway, and the stem cell regulatory signaling pathway. In particular, target gene prediction of the top three miRNAs with upregulated expression showed that they targeted SMAD, GREM1 and other genes to participate in the regulation of TGF-ß and other pathways. CONCLUSION: PIWIL2-induced cancer stem cells have significantly altered levels of miRNAs, piRNAs and mRNAs.TGF-ß, autophagy, apoptosis and other pathways may play an important role in stem cell development. The occurrence of alternative splicing and fusion genes may be related to the occurrence of cancer stem cells.


Assuntos
MicroRNAs , Acetiltransferases/genética , Proteínas Argonautas/genética , Proteínas Argonautas/metabolismo , Carcinogênese/genética , Transformação Celular Neoplásica , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Células-Tronco Neoplásicas/metabolismo , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Transcriptoma/genética , Fator de Crescimento Transformador beta/metabolismo
10.
Mol Biol Rep ; 49(7): 6957-6969, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35411481

RESUMO

BACKGROUND: CSCs play an important role in tumor development. Some studies have demonstrated that piRNAs participate in the progression of various cancers. However, the detailed function of piRNAs in CSCs requires further investigation. This study aimed to investigate the significance of novel piRNA MW557525, one of the top five up-regulated piRNAs screened by gene chip and it has been verified by RT-q-PCR that it is indeed the most obvious up-regulated expression in Piwil2-iCSCs. METHODS AND RESULTS: Differentially expressed piRNAs in Piwil2-iCSCs were screened by gene chip. Target genes were predicted by the miRanda algorithm and subjected to GO and KEGG analysis. One of the differential piRNAs, novel piRNA MW557525, was transfected and its target gene NOP56 was silenced in Piwil2-iCSCs, respectively. RT-qPCR, western blot (WB) and dual luciferase reporter assay were used to investigate the interaction of piRNA MW557525 and NOP56. We identified the effect of piRNA MW557525 and NOP56 knockdown on cell proliferation, migration, invasion, and apoptosis via CCK-8, transwell assay, and flow cytometry. The expressions of CD24, CD133, KLF4, and SOX2 were detected via WB. The results showed that piRNA MW557525 was negatively correlated with NOP56, and it promoted the proliferation, migration, invasion, and inhibited apoptosis in Piwil2-iCSCs, and it also promoted the expressions of CD24, CD133, KLF4, and SOX2, while NOP56 showed the opposite effect. CONCLUSIONS: These findings suggested that novel piRNA MW557525 might be a novel therapeutic target in Piwil2-iCSCs.


Assuntos
Células-Tronco , Proliferação de Células/genética , Análise de Sequência com Séries de Oligonucleotídeos , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Células-Tronco/metabolismo
11.
BMC Geriatr ; 22(1): 736, 2022 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-36076163

RESUMO

OBJECTIVE: Thyroid carcinoma (TC) is the most common endocrine tumor in the human body. Papillary thyroid carcinoma (PTC) accounts for more than 80% of thyroid cancers. Accurate prediction of elderly PTC can help reduce the mortality of patients. We aimed to construct a nomogram predicting cancer-specific survival (CSS) in elderly patients with PTC. METHODS: Patient information was downloaded from the Surveillance, Epidemiology, and End Results (SEER) program. Univariate and multivariate Cox regression models were used to screen the independent risk factors for patients with PTC. The nomogram of elderly patients with PTC was constructed based on the multivariate Cox regression model. We used the concordance index (C-index), the area under the receiver operating characteristic curve (AUC) and the calibration curve to test the accuracy and discrimination of the prediction model. Decision curve analysis (DCA) was used to test the clinical value of the model. RESULTS: A total of 14,138 elderly patients with PTC were included in this study. Patients from 2004 to 2015 were randomly divided into a training set (N = 7379) and a validation set (N = 3141), and data from 2016 to 2018 were divided into an external validation set (N = 3618). Proportional sub-distribution hazard model showed that age, sex, tumor size, histological grade, TNM stage, surgery and chemotherapy were independent risk factors for prognosis. In the training set, validation set and external validation set, the C-index was 0.87(95%CI: 0.852-0.888), 0.891(95%CI: 0.866-0.916) and 0.931(95%CI:0.894-0.968), respectively, indicating that the nomogram had good discrimination. Calibration curves and AUC suggest that the prediction model has good discrimination and accuracy. CONCLUSIONS: We constructed a new nomogram to predict CSS in elderly patients with PTC. Internal cross-validation and external validation indicate that the model has good discrimination and accuracy. The predictive model can help doctors and patients make clinical decisions.


Assuntos
Nomogramas , Neoplasias da Glândula Tireoide , Idoso , Humanos , Prognóstico , Programa de SEER , Câncer Papilífero da Tireoide/diagnóstico , Câncer Papilífero da Tireoide/epidemiologia , Câncer Papilífero da Tireoide/terapia , Neoplasias da Glândula Tireoide/diagnóstico , Neoplasias da Glândula Tireoide/epidemiologia , Neoplasias da Glândula Tireoide/terapia
12.
Acta Biochim Biophys Sin (Shanghai) ; 54(9): 1301-1313, 2022 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-36148954

RESUMO

Bacterial outer membrane vesicles (OMVs) are spherical microbubbles that contain biological content and are produced by gram-negative bacteria. The use of OMVs as adjuvants for cancer immunotherapy or as drug carriers for targeted therapies has attracted the interest of many scholars. However, it is unclear whether OMVs can exert direct antitumor effects and whether OMVs can inhibit pediatric tumors. Here, we explore the potential of Escherichia coli-derived OMVs to directly suppress neuroblastoma. Our results demonstrate the antitumor effects of OMVs in vitro and in vivo, and no serious adverse reactions were observed. OMV uptake into the cytoplasm and nucleus directly decreases cell stemness, DNA damage, apoptosis and cell cycle arrest, which may be the mechanisms by which OMVs suppress tumors. Our results demonstrate the potential of bacterial OMVs to be used as antitumor adjuvant therapies, increasing the number of candidates for the development of cancer therapies in the future. More relevant studies are urgently needed to demonstrate the efficacy and safety of OMVs.


Assuntos
Escherichia coli , Neuroblastoma , Criança , Humanos , Escherichia coli/metabolismo , Apoptose , Neuroblastoma/tratamento farmacológico , Proteínas da Membrana Bacteriana Externa/genética , Proteínas da Membrana Bacteriana Externa/metabolismo
13.
Sensors (Basel) ; 22(6)2022 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-35336362

RESUMO

Many transport systems in the real world can be modeled as networked systems. Due to limited resources, only a few nodes can be selected as seeds in the system, whose role is to spread required information or control signals as widely as possible. This problem can be modeled as the influence maximization problem. Most of the existing selection strategies are based on the invariable network structure and have not touched upon the condition that the network is under structural failures. Related studies indicate that such strategies may not completely tackle complicated diffusion tasks in reality, and the robustness of the information diffusion process against perturbances is significant. To give a numerical performance criterion of seeds under structural failure, a measure has been developed to define the robust influence maximization (RIM) problem. Further, a memetic optimization algorithm (MA) which includes several problem-orientated operators to improve the search ability, termed RIMMA, has been presented to deal with the RIM problem. Experimental results on synthetic networks and real-world networks validate the effectiveness of RIMMA, its superiority over existing approaches is also shown.

14.
Sensors (Basel) ; 22(13)2022 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-35808326

RESUMO

This paper presents a geometric approach for real-time forward kinematics of the general Stewart platform, which consists of two rigid bodies connected by six general serial manipulators. By describing the rigid-body motion as exponential of twist, and taking advantage of the product of exponentials formula, a step-by-step derivation of the proposed algorithm is presented. As the algorithm naturally solves all passive joint displacements, the correctness is then verified by comparing the forward-kinematic solutions from all chains. The convergence ability and robustness of the proposed algorithm are demonstrated with large amounts of numerical simulations. In all test cases, the proposed algorithm terminates within four iterations, converging with near-quadratic speed. Finally, the proposed algorithm is also implemented on a mainstream embedded motion controller. Compared with the incremental method, the proposed algorithm is more robust, with an average execution time of 0.48 ms, meeting the requirements of most applications, such as kinematic calibration, motion simulation, and real-time control.


Assuntos
Algoritmos , Fenômenos Biomecânicos , Simulação por Computador , Movimento (Física)
15.
Cancer Control ; 27(2): 1073274820930194, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32668959

RESUMO

Results from the epidemiologic studies on the relationship between hormone replacement therapy (HRT) and the risk of kidney cancer in women were not completely consistent. This meta-analysis aimed to evaluate the relationship between HRT and risk of kidney cancer in women. We performed a meta-analysis of observational studies to assess this association. The PubMed and Embase databases were searched from their inception to January 29, 2020, to identify relevant studies that fit the pre-stated inclusion criteria; reference lists from the retrieved articles were also been reviewed. Relative risks (RRs) with corresponding 95% CIs were extracted and combined using random effects models. Furthermore, dose-response, sensitivity analyses, publication bias, and subgroup analysis by study design, regional location, and exposure assessment method were conducted. Thirteen articles involving 6 cohort studies and 8 case-control studies were included in our meta-analysis. Overall, 4194 women were diagnosed with kidney cancer among 648 107 participants. The pooled RR for kidney cancer was 1.08 (95% CI: 0.96-1.22) in those who were administered HRT compared to those who had not. Subgroup analysis indicated the overall result was not influenced by study type, regional location, or adjusted variables. Dose-response analysis showed a nonlinear relationship between HRT and kidney cancer (P = .0021) and the risk of kidney cancer decreased by 15% to 28% with 12 to 18 years of HRT use. No evidence of publication bias was found (P for Egger =.111). Our meta-analysis showed that HRT use is inversely associated with kidney cancer risk in a dose-dependent fashion.


Assuntos
Terapia de Reposição Hormonal/efeitos adversos , Neoplasias Renais/etiologia , Estudos de Casos e Controles , Relação Dose-Resposta a Droga , Feminino , Humanos , Neoplasias Renais/diagnóstico , Fatores de Risco , Fatores de Tempo
16.
EMBO J ; 34(4): 475-90, 2015 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-25588945

RESUMO

Lysosomal degradation is essential for the termination of EGF-stimulated EGF receptor (EGFR) signaling. This requires EGFR sorting to the intraluminal vesicles (ILVs) of multi-vesicular endosomes (MVEs). Cytosolic proteins including the ESCRT machineries are key regulators of EGFR intraluminal sorting, but roles for endosomal transmembrane proteins in receptor sorting are poorly defined. Here, we show that LAPTM4B, an endosomal transmembrane oncoprotein, inhibits EGF-induced EGFR intraluminal sorting and lysosomal degradation, leading to enhanced and prolonged EGFR signaling. LAPTM4B blocks EGFR sorting by promoting ubiquitination of Hrs (an ESCRT-0 subunit), which inhibits the Hrs association with ubiquitinated EGFR. This is counteracted by the endosomal PIP kinase, PIPKIγi5, which directly binds LAPTM4B and neutralizes the inhibitory function of LAPTM4B in EGFR sorting by generating PtdIns(4,5)P2 and recruiting SNX5. PtdIns(4,5)P2 and SNX5 function together to protect Hrs from ubiquitination, thereby promoting EGFR intraluminal sorting. These results reveal an essential layer of EGFR trafficking regulated by LAPTM4B, PtdIns(4,5)P2 signaling, and the ESCRT complex and define a mechanism by which the oncoprotein LAPTM4B can transform cells and promote tumor progression.


Assuntos
Receptores ErbB/metabolismo , Lisossomos/metabolismo , Proteínas de Membrana/metabolismo , Proteínas Oncogênicas/metabolismo , Fosfatidilinositóis/metabolismo , Linhagem Celular , Humanos , Proteínas de Membrana/genética , Microscopia de Fluorescência , Modelos Biológicos , Proteínas Oncogênicas/genética , Ligação Proteica , Transdução de Sinais/fisiologia , Nexinas de Classificação/metabolismo
17.
J Neuroinflammation ; 16(1): 20, 2019 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-30700305

RESUMO

Stroke is the most common cerebrovascular disease, the second leading cause of death behind heart disease and is a major cause of long-term disability worldwide. Currently, systemic immunomodulatory therapy based on intravenous cells is attracting attention. The immune response to acute stroke is a major factor in cerebral ischaemia (CI) pathobiology and outcomes. Over the past decade, the significant contribution of the spleen to ischaemic stroke has gained considerable attention in stroke research. The changes in the spleen after stroke are mainly reflected in morphology, immune cells and cytokines, and these changes are closely related to the stroke outcomes. Autonomic nervous system (ANS) activation, release of central nervous system (CNS) antigens and chemokine/chemokine receptor interactions have been documented to be essential for efficient brain-spleen cross-talk after stroke. In various experimental models, human umbilical cord blood cells (hUCBs), haematopoietic stem cells (HSCs), bone marrow stem cells (BMSCs), human amnion epithelial cells (hAECs), neural stem cells (NSCs) and multipotent adult progenitor cells (MAPCs) have been shown to reduce the neurological damage caused by stroke. The different effects of these cell types on the interleukin (IL)-10, interferon (IFN), and cholinergic anti-inflammatory pathways in the spleen after stroke may promote the development of new cell therapy targets and strategies. The spleen will become a potential target of various stem cell therapies for stroke represented by MAPC treatment.


Assuntos
Baço/fisiologia , Transplante de Células-Tronco/métodos , Acidente Vascular Cerebral/cirurgia , Animais , Citocinas/metabolismo , Humanos
18.
Proc Natl Acad Sci U S A ; 113(39): 10896-901, 2016 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-27621469

RESUMO

Autophagy is a regulated self-digestion pathway with fundamental roles in cell homeostasis and diseases. Autophagy is regulated by coordinated actions of a series of autophagy-related (ATG) proteins. The Barkor/ATG14(L)-VPS34 (a class III phosphatidylinositol 3-kinase) complex and its product phosphatidylinositol 3-phosphate [PtdIns(3)P] play key roles in autophagy initiation. ATG14 contains a C-terminal Barkor/ATG14(L) autophagosome-targeting sequence (BATS) domain that senses the curvature of PtdIns(3)P-containing membrane. The BATS domain also strongly binds PtdIns(4,5)P2, but the functional significance has been unclear. Here we show that ATG14 specifically interacts with type Iγ PIP kinase isoform 5 (PIPKIγi5), an enzyme that generates PtdIns(4,5)P2 in mammalian cells. Autophagosomes have associated PIPKIγi5 and PtdIns(4,5)P2 that are colocalized with late endosomes and the endoplasmic reticulum. PtdIns(4,5)P2 generation at these sites requires PIPKIγi5. Loss of PIPKIγi5 results in a loss of ATG14, UV irradiation resistance-associated gene, and Beclin 1 and a block of autophagy. PtdIns(4,5)P2 binding to the ATG14-BATS domain regulates ATG14 interaction with VPS34 and Beclin 1, and thus plays a key role in ATG14 complex assembly and autophagy initiation. This study identifies an unexpected role for PtdIns(4,5)P2 signaling in the regulation of ATG14 complex and autophagy.


Assuntos
Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Proteínas Relacionadas à Autofagia/metabolismo , Autofagia , Fosfatidilinositol 4,5-Difosfato/metabolismo , Proteína 5 Relacionada à Autofagia/metabolismo , Proteína Beclina-1/metabolismo , Proteínas de Transporte/metabolismo , Linhagem Celular , Retículo Endoplasmático/metabolismo , Endossomos/metabolismo , Técnicas de Silenciamento de Genes , Humanos , Mutação/genética , Fosfotransferases (Aceptor do Grupo Álcool) , Ligação Proteica , Domínios Proteicos , Transdução de Sinais , Frações Subcelulares/metabolismo
19.
BMC Nephrol ; 19(1): 31, 2018 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-29415664

RESUMO

BACKGROUND: The prognostic effect of gender on immunoglobulin A nephropathy (IgAN) is not clear. We explored gender-related differences in clinicopathological features and renal outcomes in IgAN. METHODS: This was a single-centre retrospective study. Patients were divided into two groups according to gender. The clinicopathological features at biopsy and renal outcomes during the follow-up were collected and analysed. Renal outcomes were defined as the doubling of baseline serum creatinine and end-stage renal disease (ESRD) (estimated glomerular filtration rate < 15 mL/min/1.73 m2, dialysis, or renal transplantation). The prognostic effects of gender were evaluated by Cox regression models. RESULTS: A total of 988 eligible IgAN patients were enrolled, and the ratio of males to females was 1:1.4. Compared with female patients, male patients had worse renal function, greater proteinuria, a higher prevalence of hypertension, hypertriglyceridaemia and hyperuricaemia, and more severe segmental sclerosis and tubular atrophy/interstitial fibrosis. However, haematuria occurred more frequently in female patients. During a median follow-up time of 48.6 (34.7, 62.7) months, no differences in renal survival rates were noted between the male and female groups. Multivariable Cox regression analyses revealed that gender was not a significant risk factor for renal outcomes after frequency matching of baseline eGFR and serum uric acid (SUA) levels. In addition, male and female patients shared similar risk factors, including a low eGFR and increased proteinuria and segmental sclerosis. In males, however, an elevated proportion of global glomerulosclerosis was also a poor prognostic factor for renal survival. CONCLUSIONS: Male IgAN patients presented with worse clinicopathologic features than female patients, but no significant differences were observed in long-term renal survival between male and female patients by eGFR- and SUA level-matching.


Assuntos
Glomerulonefrite por IGA/diagnóstico , Glomerulonefrite por IGA/epidemiologia , Caracteres Sexuais , Adulto , China/epidemiologia , Feminino , Seguimentos , Humanos , Masculino , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
20.
J Cell Sci ; 128(22): 4047-56, 2015 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-26574506

RESUMO

Phosphoinositides are a collection of lipid messengers that regulate most subcellular processes. Amongst the seven phosphoinositide species, the roles for phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] at the plasma membrane, such as in endocytosis, exocytosis, actin polymerization and focal adhesion assembly, have been extensively studied. Recent studies have argued for the existence of PtdIns(4,5)P2 at multiple intracellular compartments, including the nucleus, endosomes, lysosomes, autolysosomes, autophagic precursor membranes, ER, mitochondria and the Golgi complex. Although the generation, regulation and functions of PtdIns(4,5)P2 are less well-defined in most other intracellular compartments, accumulating evidence demonstrates crucial roles for PtdIns(4,5)P2 in endolysosomal trafficking, endosomal recycling, as well as autophagosomal pathways, which are the focus of this Commentary. We summarize and discuss how phosphatidylinositol phosphate kinases, PtdIns(4,5)P2 and PtdIns(4,5)P2-effectors regulate these intracellular protein and membrane trafficking events.


Assuntos
Fosfatidilinositol 4,5-Difosfato/metabolismo , Animais , Membrana Celular/metabolismo , Humanos , Fosfatidilinositóis/metabolismo , Transdução de Sinais
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