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1.
EMBO J ; 41(15): e110472, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35686621

RESUMO

Microtubules tightly regulate various cellular activities. Our understanding of microtubules is largely based on experiments using microtubule-targeting agents, which, however, are insufficient to dissect the dynamic mechanisms of specific microtubule populations, due to their slow effects on the entire pool of microtubules. To overcome this technological limitation, we have used chemo and optogenetics to disassemble specific microtubule subtypes, including tyrosinated microtubules, primary cilia, mitotic spindles, and intercellular bridges, by rapidly recruiting engineered microtubule-cleaving enzymes onto target microtubules in a reversible manner. Using this approach, we show that acute microtubule disassembly swiftly halts vesicular trafficking and lysosomal dynamics. It also immediately triggers Golgi and ER reorganization and slows the fusion/fission of mitochondria without affecting mitochondrial membrane potential. In addition, cell rigidity is increased after microtubule disruption owing to increased contractile stress fibers. Microtubule disruption furthermore prevents cell division, but does not cause cell death during interphase. Overall, the reported tools facilitate detailed analysis of how microtubules precisely regulate cellular architecture and functions.


Assuntos
Microtúbulos , Fuso Acromático , Interfase , Microtúbulos/metabolismo , Fuso Acromático/metabolismo
2.
Int Wound J ; 21(1): e14338, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37555265

RESUMO

This study aims to investigate whether the current wound classifications were valid for the treatment prognosis of subjects treated for limb-threatening diabetic foot ulcers (LTDFU). A total of 1548 patients with LTDFU and infection were studied, with wounds recorded using the Wagner, Texas, PEDIS and WIfI classifications while major lower extremity amputations (LEAs) or in-hospital mortality incidences were defined as poor outcomes. Among them, 153 (9.9%) patients received major LEAs and 38 (2.5%) patients died. After adjustments, the Wagner classification and Texas stage as well as clinical factors such as comorbidity with major adverse cardiac events (MACE), being under dialysis and having serum levels of C-reactive protein (CRP) and albumin were independent factors for prognosis. For patients without dialysis, Wagner and Texas stage stood out independently for prognosis. For patients on dialysis, only levels of CRP (odds ratio [OR] = 2.2 in Wagner, OR = 2.0 in WIfI, OR = 2.2 in Texas, OR = 2.3 in PEDIS) and albumin (OR = 0.4 in four classifications) were valid predictors. The Wagner system and Texas stage were valid for predicting prognosis in treatment for LTDFUs, suggesting a role of vascular perfusion. MACE history, levels of CRP and albumin level should assist in prediction; more significantly, only levels of CRP and albumin appeared valid for those subjects undergoing dialysis.


Assuntos
Diabetes Mellitus , Pé Diabético , Humanos , Pé Diabético/cirurgia , Fatores de Risco , Cicatrização , Prognóstico , Extremidade Inferior , Salvamento de Membro/efeitos adversos , Albuminas , Estudos Retrospectivos , Isquemia/terapia , Resultado do Tratamento
3.
Paediatr Perinat Epidemiol ; 37(3): 191-200, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36562434

RESUMO

BACKGROUND: Tic disorders are common neurodevelopmental disorders during childhood. Whether prenatal and postnatal exposure to particulate matter with an aerodynamic diameter less than 2.5 µm (PM2.5 ) plays a role in the development of tic disorders remains unexplored. OBJECTIVES: To investigate the association of exposure between PM2.5 during the pregnancy and infancy periods and the risk of tic disorders. METHODS: This birth cohort study recruited singleton live births at term gestations in central Taiwan from the Taiwan Maternal and Child Health Database between 2004 and 2012 and followed up to the end of 2017. New cases of tic disorders were defined using the ICD-9-CM (307.2) and ICD-10-CM (F95), which include all tic spectrum disorders. We assigned daily PM2.5 concentrations derived from a satellite-based model to individuals based on maternal residential addresses at delivery. We fit Cox proportional hazard model and distributed lag non-linear model to estimate the associations between PM2.5 and tic disorders, with hazard ratio (HR) with 95% confidence interval (CI) as the effect measure. RESULTS: Of the 309,376 singleton live births at term gestations, we identified 5902 (1.9%) tic disorder cases. The HR of tic disorders was positively associated with a 10 µg/m3 increase in PM2.5 : during pregnancy HR 1.09, 95% CI 1.04, 1.15 and during infancy HR 1.12, 95% CI 1.06, 1.18. The vulnerable time window for infants with increased risk of tic disorders was 6-52 weeks after birth. We observed a nonlinear relationship between PM2.5 and the risk of tic disorders, with exposure to PM2.5 between 16 and 64 µg/m3 being associated with the risk of tic disorders. The association was restricted to Tourette's disorder group. Infant sex did not modify these associations. CONCLUSIONS: Infants delivered at term and exposed to PM2.5 are associated with an increased risk of tic disorders (6-52 weeks). Further studies are needed to confirm these associations.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Transtornos de Tique , Criança , Feminino , Humanos , Lactente , Gravidez , Poluentes Atmosféricos/efeitos adversos , Poluição do Ar/efeitos adversos , Poluição do Ar/análise , Estudos de Coortes , Exposição Materna/efeitos adversos , Material Particulado/efeitos adversos , Material Particulado/análise , Transtornos de Tique/epidemiologia , Transtornos de Tique/etiologia , Vitaminas
4.
Environ Res ; 231(Pt 2): 116154, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37187309

RESUMO

BACKGROUND: Few studies have explored the association between maternal exposure to particulate matter with an aerodynamic diameter of ≤2.5 µm (PM2.5) and congenital heart defects occurring before and during pregnancy. We aimed to investigate the association and the critical time windows between the maternal exposure to PM2.5 and congenital heart defects. METHOD: We conducted a cohort-based case-control study of 507,960 participants obtained from the Taiwan Maternal and Child Health Database between 2004 and 2015. We applied satellite-based spatiotemporal models with 1-km resolution to calculate the average PM2.5 concentration during preconception and the specific periods of pregnancy. We also performed conditional logistic regression with distributed lag non-linear models (DLNMs) to assess the effects of weekly average PM2.5 on both congenital heart defects and their isolated subtypes, as well as the concentration-response relationships. RESULTS: In DLNMs, exposure to PM2.5 (per 10 µg/m3) during weeks 7-12 before conception and weeks 3-9 after conception was associated with congenital heart defects. The strongest association at 12 weeks before conception (odds ratio [OR] = 1.026, 95% confidence intervals [CI]: 1.012-1.040) and 7 weeks after conception (OR = 1.024, 95% CI: 1.012-1.036) for every 10 µg/m3 increase in PM2.5 concentration. In modification analysis, strongest associations were observed for low SES. CONCLUSIONS: Our study revealed that exposure to ambient PM2.5 raises the risk of congenital heart defects, particularly among individuals with lower socioeconomic status. Moreover, our findings suggest that preconception exposure to PM2.5 may be a crucial period for the development of congenital heart defects.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Cardiopatias Congênitas , Gravidez , Criança , Feminino , Humanos , Material Particulado/toxicidade , Material Particulado/análise , Exposição Materna/efeitos adversos , Poluentes Atmosféricos/toxicidade , Poluentes Atmosféricos/análise , Taiwan/epidemiologia , Estudos de Casos e Controles , Saúde da Criança , Cardiopatias Congênitas/induzido quimicamente , Cardiopatias Congênitas/epidemiologia , Poluição do Ar/efeitos adversos , Poluição do Ar/análise
5.
Environ Res ; 237(Pt 1): 116874, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37595830

RESUMO

Autism spectrum disorder (ASD) is a group of neurodevelopmental disorders, and its incidence is increasing over time. Although several environmental factors have been suspected to be risk factors for ASD, studies on the effects of airborne heavy metals on newly developed ASD are still limited. We conducted a large birth cohort study of 168,062 live term births in Taichung during 2004-2011 to assess the association of heavy metals in particulate matter with an aerodynamic diameter less than 2.5 µm (PM2.5) with ASD, and identify sensitive time windows during prenatal and postnatal periods. Heavy metals, including arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) in PM2.5, were estimated using the Weather Research and Forecasting/Chem (WRF/Chem), inserted from the top 75 emission sources for the module. The association between childhood ASD and 4 metals were analyzed from pregnancy to 9 months after birth. The Cox proportional hazard model with a distributed lag nonlinear model (DLNM) was used to estimate the association between heavy metals in PM2.5 and ASD. We identified 666 incident ASD cases in 168,062 participants. A positive association between Hg and ASD was found at 9 months after birth (Hazard Ratio: 1.63; 95% CI: 1.13-2.36). According to the DLNM, there was an increased risk of exposure to Hg during 10-25 weeks after birth, and decreased risk of exposure to Hg during gestational weeks 4-6. Exposure to As and Hg on the risk of ASD were significantly stronger in low birth weight infants (<2500 g) than in those of birth weight ≥2500 g during postnatal period. Postnatal exposure to Hg in PM2.5 may associate with increased ASD incidence. Infants with low birth weight and exposure to As and Hg in PM2.5 are more likely to develop ASD.

6.
Environ Res ; 214(Pt 1): 113769, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35777438

RESUMO

Only a few studies have assessed the effects of fine particulate matter (PM2.5) exposure during the prenatal and postnatal periods on the development of attention-deficit/hyperactivity disorder (ADHD). We investigated the association of exposure to PM2.5 during pregnancy and early life with ADHD. This birth cohort consisted of 425,736 singleton live-term births between 2004 and 2015 in Taiwan. Daily PM2.5 concentrations were derived from a 1-km satellite-based estimation model. A time-dependent Cox model was used to assess the effects of PM2.5 on ADHD during the first, second, and third trimesters and from age 1-5 years after birth. The distributed lag nonlinear model was utilized to explore the dose-response relationship. Total 9,294 children were diagnosed with ADHD during the study period. The hazard ratio (HR) of ADHD was significantly associated with a 10 µg/m3 increase in PM2.5 during the first trimester (HR = 1.26; 95% confidence interval [CI]: 1.13-1.40) and increased at PM2.5 over 16 µg/m3. For postnatal periods, the HR of ADHD was significantly associated with increased PM2.5 at the first to third year of life (HR ranged between 1.40 and 1.87). According to the dose-response relationship of exposure to PM2.5 at the third year of life, the HR of ADHD was significantly associated with PM2.5 above 16 µg/m3 and sharply increased as PM2.5 >50 µg/m3. We did not observe a significant modification of sex on the relation between PM2.5 and ADHD. Exposure of pregnant women to PM2.5 above 16 µg/m3 from conception to the early life of their children may increase the risk of ADHD. The government should improve the criteria for air quality control and meet the WHO air quality guidelines to protect pregnant women and children from developing ADHD in the future.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Transtorno do Deficit de Atenção com Hiperatividade , Efeitos Tardios da Exposição Pré-Natal , Coorte de Nascimento , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Humanos , Lactente , Exposição Materna , Material Particulado , Gravidez , Vitaminas
7.
Thorax ; 76(6): 568-574, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33707186

RESUMO

BACKGROUND: The effect of prenatal and postnatal exposure to fine particulate matter (PM2.5) on the development of allergic rhinitis (AR) is poorly understood. We further identified the vulnerable period for AR development to determine methods to decrease adverse effects. METHODS: We used a large population-based birth cohort of 140 911 singleton live infants in Taichung, Taiwan with a highly temporal-resolution satellite-based hybrid model to evaluate the effects of prenatal and early postnatal exposure on the onset of AR. RESULTS: Among 140 911 children, 47 276 (33.55%) were cases of incident AR. The mean age of the children with AR at initial diagnosis was 2.97±1.78 years. We identified a significant association of AR with an interquartile range (IQR 17.98 µg/m3) increase in PM2.5 from 30 gestational weeks to 52 weeks after birth. The exposure-response relationship revealed that AR had a significant positive association between PM2.5 of 26-76 µg/m3 (adjusted hazard ratios ranged from 1.00 to 1.05). CONCLUSION: Our study provides evidence that both prenatal and postnatal exposures to PM2.5 are associated with later development of AR. The vulnerable time window may be within late gestation and the first year of life. Further study is required to confirm the vulnerable time period of PM2.5 on AR.


Assuntos
Poluição do Ar/efeitos adversos , Exposição Materna/efeitos adversos , Material Particulado/efeitos adversos , Efeitos Tardios da Exposição Pré-Natal/epidemiologia , Rinite Alérgica/etiologia , Pré-Escolar , Feminino , Seguimentos , Humanos , Incidência , Masculino , Gravidez , Estudos Retrospectivos , Rinite Alérgica/epidemiologia , Taiwan/epidemiologia , Fatores de Tempo
8.
Nano Lett ; 20(2): 1089-1100, 2020 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-31884787

RESUMO

Biomolecules that respond to different external stimuli enable the remote control of genetically modified cells. We report herein a sonogenetic approach that can manipulate target cell activities by focused ultrasound stimulation. This system requires an ultrasound-responsive protein derived from an engineered auditory-sensing protein prestin. Heterologous expression of mouse prestin containing two parallel amino acid substitutions, N7T and N308S, that frequently exist in prestins from echolocating species endowed transfected mammalian cells with the ability to sense ultrasound. An ultrasound pulse of low frequency and low pressure efficiently evoked cellular calcium responses after transfecting with prestin(N7T, N308S). Moreover, pulsed ultrasound can also noninvasively stimulate target neurons expressing prestin(N7T, N308S) in deep regions of mouse brains. Our study delineates how an engineered auditory-sensing protein can cause mammalian cells to sense ultrasound stimulation. Moreover, our sonogenetic tools will serve as new strategies for noninvasive therapy in deep tissues.


Assuntos
Encéfalo/metabolismo , Audição/genética , Proteínas Motores Moleculares/genética , Neurônios/metabolismo , Animais , Ecolocação , Audição/fisiologia , Humanos , Camundongos , Proteínas Motores Moleculares/química , Neurônios/química , Engenharia de Proteínas/métodos , Ondas Ultrassônicas
9.
Int J Mol Sci ; 22(10)2021 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-34065507

RESUMO

Small ubiquitin-like modifier (SUMO)-targeted E3 ubiquitin ligases (STUbLs) are specialized enzymes that recognize SUMOylated proteins and attach ubiquitin to them. They therefore connect the cellular SUMOylation and ubiquitination circuits. STUbLs participate in diverse molecular processes that span cell cycle regulated events, including DNA repair, replication, mitosis, and transcription. They operate during unperturbed conditions and in response to challenges, such as genotoxic stress. These E3 ubiquitin ligases modify their target substrates by catalyzing ubiquitin chains that form different linkages, resulting in proteolytic or non-proteolytic outcomes. Often, STUbLs function in compartmentalized environments, such as the nuclear envelope or kinetochore, and actively aid in nuclear relocalization of damaged DNA and stalled replication forks to promote DNA repair or fork restart. Furthermore, STUbLs reside in the same vicinity as SUMO proteases and deubiquitinases (DUBs), providing spatiotemporal control of their targets. In this review, we focus on the molecular mechanisms by which STUbLs help to maintain genome stability across different species.


Assuntos
Instabilidade Genômica/genética , Proteínas Modificadoras Pequenas Relacionadas à Ubiquitina/genética , Sumoilação/genética , Ubiquitina-Proteína Ligases/genética , Ubiquitina/genética , Animais , Reparo do DNA/genética , Humanos
10.
Int J Mol Sci ; 22(19)2021 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-34638904

RESUMO

Group A Streptococcus (GAS) causes invasive human diseases with the cytokine storm. Interleukin-33 (IL-33)/suppression of tumorigenicity 2 (ST2) axis is known to drive TH2 response, while its effect on GAS infection is unclear. We used an air pouch model to examine the effect of the IL-33/ST2 axis on GAS-induced necrotizing fasciitis. GAS infection induced IL-33 expression in wild-type (WT) C57BL/6 mice, whereas the IL-33- and ST2-knockout mice had higher mortality rates, more severe skin lesions and higher bacterial loads in the air pouches than those of WT mice after infection. Surveys of infiltrating cells in the air pouch of GAS-infected mice at the early stage found that the number and cell viability of infiltrating cells in both gene knockout mice were lower than those of WT mice. The predominant effector cells in GAS-infected air pouches were neutrophils. Absence of the IL-33/ST2 axis enhanced the expression of inflammatory cytokines, but not TH1 or TH2 cytokines, in the air pouch after infection. Using in vitro assays, we found that the IL-33/ST2 axis not only enhanced neutrophil migration but also strengthened the bactericidal activity of both sera and neutrophils. These results suggest that the IL-33/ST2 axis provided the protective effect on GAS infection through enhancing the innate immunity.


Assuntos
Imunidade Inata/imunologia , Proteína 1 Semelhante a Receptor de Interleucina-1/imunologia , Interleucina-33/imunologia , Infecções Estreptocócicas/imunologia , Streptococcus pyogenes/imunologia , Animais , Movimento Celular/imunologia , Citocinas/imunologia , Citocinas/metabolismo , Modelos Animais de Doenças , Humanos , Inflamação/imunologia , Inflamação/metabolismo , Inflamação/microbiologia , Proteína 1 Semelhante a Receptor de Interleucina-1/metabolismo , Interleucina-33/genética , Interleucina-33/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neutrófilos/citologia , Neutrófilos/imunologia , Neutrófilos/microbiologia , Transdução de Sinais/imunologia , Infecções Estreptocócicas/microbiologia , Streptococcus pyogenes/fisiologia
11.
Int J Mol Sci ; 22(21)2021 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-34769046

RESUMO

Streptococcus pyogenes (group A Streptococcus (GAS) is an important human pathogen that can cause severe invasive infection, such as necrotizing fasciitis and streptococcal toxic shock syndrome. The mortality rate of streptococcal toxic shock syndrome ranges from 20% to 50% in spite of antibiotics administration. AR-12, a pyrazole derivative, has been reported to inhibit the infection of viruses, intracellular bacteria, and fungi. In this report, we evaluated the bactericidal activities and mechanisms of AR-12 on GAS infection. Our in vitro results showed that AR-12 dose-dependently reduced the GAS growth, and 2.5 µg/mL of AR-12 significantly killed GAS within 2 h. AR-12 caused a remarkable reduction in nucleic acid and protein content of GAS. The expression of heat shock protein DnaK and streptococcal exotoxins was also inhibited by AR-12. Surveys of the GAS architecture by scanning electron microscopy revealed that AR-12-treated GAS displayed incomplete septa and micro-spherical structures protruding out of cell walls. Moreover, the combination of AR-12 and gentamicin had a synergistic antibacterial activity against GAS replication for both in vitro and in vivo infection. Taken together, these novel findings obtained in this study may provide a new therapeutic strategy for invasive GAS infection.


Assuntos
Antibacterianos/farmacologia , Gentamicinas/farmacologia , Pirazóis/farmacologia , Streptococcus pyogenes/efeitos dos fármacos , Sulfonamidas/farmacologia , Células A549 , Animais , Linhagem Celular , Linhagem Celular Tumoral , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Células RAW 264.7 , Choque Séptico/tratamento farmacológico , Infecções Estreptocócicas/tratamento farmacológico , Células U937
12.
Hu Li Za Zhi ; 67(4): 98-105, 2020 Aug.
Artigo em Zh | MEDLINE | ID: mdl-32748384

RESUMO

BACKGROUND & PROBLEMS: Poor sleep quality during hospitalization may lead to post-hospital symptoms and increase readmission rates and mortality. Patients in our intensive care unit (ICU) reported low mean scores on the Richards-Campbell Sleep Questionnaire (RCSQ) during their third and fifth days of hospitalization (49.7 mm and 51.7 mm, respectively). Therefore, a project to improve sleep quality in the ICU was established. PURPOSE: To increase the mean RCSQ score from 51.7 mm to 76.0 mm on the fifth day. The fifth day timeframe was chosen because of the disease conditions of the patients and related clinical-medical factors. RESOLUTIONS: The project team proposed an evidence-based, sleep care bundle that included non-medication pain control, environmental regulation, improvement of the care process, and individualized sleep care. RESULTS: After implementing the bundled intervention, the mean RCSQ score of patients in our ICU increased from 49.7 mm to 55.9 mm on the third day and from 51.7 mm to 80.9 mm on the fifth day. CONCLUSIONS: This application of a sleep care bundle effectively improved the factors affecting sleep disturbance and improved quality of sleep in the patients in our intensive care unit.


Assuntos
Unidades de Terapia Intensiva , Pacotes de Assistência ao Paciente/enfermagem , Sono , Humanos , Pesquisa em Avaliação de Enfermagem , Transtornos do Sono-Vigília/prevenção & controle , Inquéritos e Questionários
13.
PLoS Genet ; 10(9): e1004675, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25255315

RESUMO

Mutations in VCP (Valosin-containing protein), an AAA ATPase critical for ER-associated degradation, are linked to IBMPFD (Inclusion body myopathy with Paget disease and frontotemporal dementia). Using a Drosophila IBMPFD model, we have identified the ER protein Derlin-1 as a modifier of pathogenic TER94 (the fly VCP homolog) mutants. Derlin-1 binds to TER94 directly, and this interaction is essential for Derlin-1 overexpression to suppress the pathogenic TER94-induced neurodegeneration. Derlin-1 overexpression reduces the elevated ATPase activity of pathogenic TER94, implying that IBMPFD is caused by ATPase hyper-activation. Under physiological condition, Derlin-1 expression is increased upon ER stress to recruit TER94 to the ER. However, in response to severe ER stress, Derlin-1 is required for activating apoptosis to eliminate damaged cells. This pro-apoptotic response is mimicked by Derlin-1 overexpression, which elicits acute ER stress and triggers apoptosis via a novel C-terminal motif (α). As this Derlin-1-dependent cell death is negated by TER94 overexpression, we propose that while Derlin-1 and VCP work cooperatively in ER stress response, their imbalance has a role in removing cells suffering prolonged ER stress.


Assuntos
Adenosina Trifosfatases/genética , Apoptose/genética , Proteínas de Drosophila/genética , Estresse do Retículo Endoplasmático/genética , Proteínas de Membrana/genética , Mutação , Animais , Caspases/metabolismo , Modelos Animais de Doenças , Drosophila , Proteínas de Drosophila/metabolismo , Degradação Associada com o Retículo Endoplasmático/genética , Ativação Enzimática , Expressão Gênica , Proteínas de Membrana/química , Proteínas de Membrana/metabolismo , Mitocôndrias/genética , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Mitocôndrias/ultraestrutura , Modelos Moleculares , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/metabolismo , Fenótipo , Ligação Proteica , Conformação Proteica , Domínios e Motivos de Interação entre Proteínas , Proteína com Valosina
14.
Int J Mol Sci ; 18(1)2016 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-28035994

RESUMO

Colorectal cancer is the third most common cancer worldwide. Aberrant overexpression of antiapoptotic BCL-2 (B-cell lymphoma 2) family proteins is closely linked to tumorigenesis and poor prognosis in colorectal cancer. Obatoclax is an inhibitor targeting all antiapoptotic BCL-2 proteins. A previous study has described the antiproliferative action of obatoclax in one human colorectal cancer cell line without elucidating the underlying mechanisms. We herein reported that, in a panel of human colorectal cancer cell lines, obatoclax inhibits cell proliferation, suppresses clonogenicity, and induces G1-phase cell cycle arrest, along with cyclin D1 downregulation. Notably, ectopic cyclin D1 overexpression abrogated clonogenicity suppression but also G1-phase arrest elicited by obatoclax. Mechanistically, pre-treatment with the proteasome inhibitor MG-132 restored cyclin D1 levels in all obatoclax-treated cell lines. Cycloheximide chase analyses further revealed an evident reduction in the half-life of cyclin D1 protein by obatoclax, confirming that obatoclax downregulates cyclin D1 through induction of cyclin D1 proteasomal degradation. Lastly, threonine 286 phosphorylation of cyclin D1, which is essential for initiating cyclin D1 proteasomal degradation, was induced by obatoclax in one cell line but not others. Collectively, we reveal a novel anticancer mechanism of obatoclax by validating that obatoclax targets cyclin D1 for proteasomal degradation to downregulate cyclin D1 for inducing antiproliferation.


Assuntos
Carcinoma/metabolismo , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/metabolismo , Ciclina D1/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Pirróis/farmacologia , Regulação para Baixo , Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos dos fármacos , Células HCT116 , Células HT29 , Humanos , Indóis , Proteólise , Pirróis/toxicidade
15.
Mol Cancer ; 14: 36, 2015 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-25888956

RESUMO

BACKGROUND: MicroRNAs (miRNAs) are short, non-coding RNA molecules that play critical roles in human malignancy. However, the regulatory characteristics of miRNAs in triple-negative breast cancer, a phenotype of breast cancer that does not express the genes for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2, are still poorly understood. METHODS: In this study, miRNA expression profiles of 24 triple-negative breast cancers and 14 adjacent normal tissues were analyzed using deep sequencing technology. Expression levels of miRNA reads were normalized with the quantile-quantile scaling method. Deregulated miRNAs in triple-negative breast cancer were identified from the sequencing data using the Student's t-test. Quantitative reverse transcription PCR validations were carried out to examine miRNA expression levels. Potential target candidates of a miRNA were predicted using published target prediction algorithms. Luciferase reporter assay experiments were performed to verify a putative miRNA-target relationship. Validated molecular targets of the deregulated miRNAs were retrieved from curated databases and their associations with cancer progression were discussed. RESULTS: A novel 25-miRNA expression signature was found to effectively distinguish triple-negative breast cancers from surrounding normal tissues in a hierarchical clustering analysis. We documented the evidence of seven polycistronic miRNA clusters preferentially harboring deregulated miRNAs in triple-negative breast cancer. Two of these miRNA clusters (miR-143-145 at 5q32 and miR-497-195 at 17p13.1) were markedly down-regulated in triple-negative breast cancer, while the other five miRNA clusters (miR-17-92 at 13q31.3, miR-183-182 at 7q32.2, miR-200-429 at 1p36.33, miR-301b-130b at 22q11.21, and miR-532-502 at Xp11.23) were up-regulated in triple-negative breast cancer. Moreover, miR-130b-5p from the miR-301b-130b cluster was shown to directly repress the cyclin G2 (CCNG2) gene, a crucial cell cycle regulator, in triple-negative breast cancer cells. Luciferase reporter assays showed that miR-130b-5p-mediated repression of CCNG2 was dependent on the sequence of the 3'-untranslated region. The findings described in this study implicate a miR-130b-5p-CCNG2 axis that may be involved in the malignant progression of triple-negative breast cancer. CONCLUSIONS: Our work delivers a clear picture of the global miRNA regulatory characteristics in triple-negative breast cancer and extends the current knowledge of microRNA regulatory network.


Assuntos
Regulação Neoplásica da Expressão Gênica/genética , MicroRNAs/genética , Transcriptoma/genética , Neoplasias de Mama Triplo Negativas/genética , Regiões 3' não Traduzidas/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Proteínas de Ciclo Celular/genética , Linhagem Celular , Linhagem Celular Tumoral , Ciclina G2/genética , Regulação para Baixo/genética , Feminino , Células HEK293 , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Pessoa de Meia-Idade , Regulação para Cima/genética
16.
PLoS Genet ; 7(2): e1001288, 2011 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-21304887

RESUMO

Inclusion body myopathy with Paget's disease of bone and frontotemporal dementia (IBMPFD) is caused by mutations in Valosin-containing protein (VCP), a hexameric AAA ATPase that participates in a variety of cellular processes such as protein degradation, organelle biogenesis, and cell-cycle regulation. To understand how VCP mutations cause IBMPFD, we have established a Drosophila model by overexpressing TER94 (the sole Drosophila VCP ortholog) carrying mutations analogous to those implicated in IBMPFD. Expression of these TER94 mutants in muscle and nervous systems causes tissue degeneration, recapitulating the pathogenic phenotypes in IBMPFD patients. TER94-induced neurodegenerative defects are enhanced by elevated expression of wild-type TER94, suggesting that the pathogenic alleles are dominant active mutations. This conclusion is further supported by the observation that TER94-induced neurodegenerative defects require the formation of hexamer complex, a prerequisite for a functional AAA ATPase. Surprisingly, while disruptions of the ubiquitin-proteasome system (UPS) and the ER-associated degradation (ERAD) have been implicated as causes for VCP-induced tissue degeneration, these processes are not significantly affected in our fly model. Instead, the neurodegenerative defect of TER94 mutants seems sensitive to the level of cellular ATP. We show that increasing cellular ATP by independent mechanisms could suppress the phenotypes of TER94 mutants. Conversely, decreasing cellular ATP would enhance the TER94 mutant phenotypes. Taken together, our analyses have defined the nature of IBMPFD-causing VCP mutations and made an unexpected link between cellular ATP level and IBMPFD pathogenesis.


Assuntos
Trifosfato de Adenosina/metabolismo , Proteínas de Ciclo Celular/genética , Modelos Animais de Doenças , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Demência Frontotemporal/genética , Miosite de Corpos de Inclusão/genética , Osteíte Deformante/genética , Adenosina Trifosfatases/genética , Trifosfato de Adenosina/genética , Alelos , Animais , Proteínas de Ciclo Celular/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Demência Frontotemporal/metabolismo , Humanos , Mutação , Miosite de Corpos de Inclusão/metabolismo , Osteíte Deformante/metabolismo , Ubiquitina/metabolismo , Proteína com Valosina
17.
DNA Repair (Amst) ; 135: 103646, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38340377

RESUMO

Eukaryotic genome stability is maintained by a complex and diverse set of molecular processes. One class of enzymes that promotes proper DNA repair, replication and cell cycle progression comprises small ubiquitin-like modifier (SUMO)-targeted E3 ligases, or STUbLs. Previously, we reported a role for the budding yeast STUbL synthetically lethal with sgs1 (Slx) 5/8 in preventing G2/M-phase arrest in a minichromosome maintenance protein 10 (Mcm10)-deficient model of replication stress. Here, we extend these studies to human cells, examining the requirement for the human STUbL RING finger protein 4 (RNF4) in MCM10 mutant cancer cells. We find that MCM10 and RNF4 independently promote origin firing but regulate DNA synthesis epistatically and, unlike in yeast, the negative genetic interaction between RNF4 and MCM10 causes cells to accumulate in G1-phase. When MCM10 is deficient, RNF4 prevents excessive DNA under-replication at hard-to-replicate regions that results in large DNA copy number alterations and severely reduced viability. Overall, our findings highlight that STUbLs participate in species-specific mechanisms to maintain genome stability, and that human RNF4 is required for origin activation in the presence of chronic replication stress.


Assuntos
Reparo do DNA , Instabilidade Genômica , Humanos , Replicação do DNA , Mitose , Saccharomyces cerevisiae/genética , Proteínas Nucleares/genética , Fatores de Transcrição
18.
Diabetol Metab Syndr ; 16(1): 26, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38254155

RESUMO

BACKGROUND: Immune checkpoint inhibitors (ICI) are promising treatment options for various cancers. However, their use is associated with immune-related adverse events (irAEs), including ICI-induced diabetes mellitus (ICI-DM). This study aimed to investigate the clinical features of ICI-DM, with a particular focus on alterations to pancreatic volume. METHODS: We conducted a retrospective review of 2829 patients who received ICI treatment at the Chang Gung Memorial Hospital, Linkou, between January 2014 and December 2021. New-onset diabetes or diabetic ketoacidosis (DKA) was identified in ten patients receiving ICI therapy. Pancreatic volumes were assessed by manual segmentation of computed tomography (CT) images before and after ICI-DM diagnosis. RESULTS: Among these ten patients, nivolumab was the most commonly used ICI (50.0%), followed by pembrolizumab (30.0%) and atezolizumab (20.0%). One patient received combination therapy with nivolumab and ipilimumab. The median age was 63.01 years (range: 40.1 - 87.8). ICI-DM developed after a median of 13.5 cycles (range: 2 - 42) of ICI treatment or 9.85 months (range:1.5 - 21.3) since ICI initiation. The initial presentation was DKA in 60.0% of patients. All patients had low or undetectable C-peptide levels (range: <0.033 - 0.133 nmol/L) and were negative for most type 1 diabetes mellitus (T1DM)-related autoantibodies; only one patient tested positive for glutamic acid decarboxylase antibodies. CT imaging revealed significant pancreatic atrophy, with a median pancreatic volume decrease of 19.92% (P = 0.038) from baseline and sustained significant decline at last follow-up (median - 37.14%, P = 0.012). CONCLUSIONS: ICI-DM is often accompanied by pancreatic atrophy and approximately two-thirds of patients initially present with DKA. Although the majority of ICI-DM patients lack T1DM-related autoantibodies, identifying diminished pancreatic volumes through CT imaging provides valuable clues into the subclinical aspects of ICI-DM development, aiding in the prevention of diabetic emergencies. TRIAL REGISTRATION: Not applicable.

19.
Sci Rep ; 14(1): 2508, 2024 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-38291084

RESUMO

Current approaches to define chemical-genetic interactions (CGIs) in human cell lines are resource-intensive. We designed a scalable chemical-genetic screening platform by generating a DNA damage response (DDR)-focused custom sgRNA library targeting 1011 genes with 3033 sgRNAs. We performed five proof-of-principle compound screens and found that the compounds' known modes-of-action (MoA) were enriched among the compounds' CGIs. These scalable screens recapitulated expected CGIs at a comparable signal-to-noise ratio (SNR) relative to genome-wide screens. Furthermore, time-resolved CGIs, captured by sequencing screens at various time points, suggested an unexpected, late interstrand-crosslinking (ICL) repair pathway response to camptothecin-induced DNA damage. Our approach can facilitate screening compounds at scale with 20-fold fewer resources than commonly used genome-wide libraries and produce biologically informative CGI profiles.


Assuntos
Sistemas CRISPR-Cas , RNA Guia de Sistemas CRISPR-Cas , Humanos , Genoma , Testes Genéticos , Dano ao DNA
20.
ACS Omega ; 9(9): 10253-10266, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38463297

RESUMO

Inflammatory bowel disease alters the gut microbiota, causes defects in mucosal barrier function, and leads to dysregulation of the immune response to microbial stimulation. This study investigated and compared the efficacy of a candidate probiotic strain, Bacillus coagulans BC198, and its heat-killed form in treating dextran sulfate sodium-induced colitis. Both live and heat-killed B. coagulans BC198 increased gut barrier-associated protein expression, reduced neutrophil and M1 macrophage infiltration of colon tissue, and corrected gut microbial dysbiosis induced by colitis. However, only live B. coagulans BC198 could alleviate the general symptoms of colitis, prevent colon shortening, and suppress inflammation and tissue damage. At the molecular level, live B. coagulans BC198 was able to inhibit Th17 cells while promoting Treg cells in mice with colitis, reduce pro-inflammatory MCP-1 production, and increase anti-inflammatory IL-10 expression in the colonic mucosa. The live form of B. coagulans BC198 functioned more effectively than the heat-killed form in ameliorating colitis by enhancing the anti-inflammatory response and promoting Treg cell accumulation in the colon.

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