Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 43
Filtrar
1.
Nat Methods ; 20(11): 1693-1703, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37770710

RESUMO

Clustered regularly interspaced short palindromic repeats (CRISPR) screening coupled with single-cell RNA sequencing has emerged as a powerful tool to characterize the effects of genetic perturbations on the whole transcriptome at a single-cell level. However, due to its sparsity and complex structure, analysis of single-cell CRISPR screening data is challenging. In particular, standard differential expression analysis methods are often underpowered to detect genes affected by CRISPR perturbations. We developed a statistical method for such data, called guided sparse factor analysis (GSFA). GSFA infers latent factors that represent coregulated genes or gene modules; by borrowing information from these factors, it infers the effects of genetic perturbations on individual genes. We demonstrated through extensive simulation studies that GSFA detects perturbation effects with much higher power than state-of-the-art methods. Using single-cell CRISPR data from human CD8+ T cells and neural progenitor cells, we showed that GSFA identified biologically relevant gene modules and specific genes affected by CRISPR perturbations, many of which were missed by existing methods, providing new insights into the functions of genes involved in T cell activation and neurodevelopment.


Assuntos
Fenômenos Biológicos , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Humanos , Linfócitos T CD8-Positivos , Teorema de Bayes , Transcriptoma , Sistemas CRISPR-Cas
2.
Int J Urol ; 31(6): 646-652, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38426591

RESUMO

INTRODUCTION: Use of indocyanine green (ICG) with near-infrared fluorescence (NIRF) has been demonstrated to be an effective tool for intraoperative assessment of bowel and ureteric vascularity. This study aimed to evaluate the impact of ICG on postsurgical outcomes such as anastomotic bowel leak and uretero-enteric stricture formation during robot-assisted cystectomy (RAC) and intracorporeal urinary diversion (ICUD). METHODS: We identified 238 patients who underwent RAC at the University of Louisville between September 2012 and August 2021. Patients were divided into two groups based on the utilization of ICG. Demographic, perioperative outcomes, and rate of anastomotic bowel leak were compared. RESULTS: In total, 138 patients were in the ICG group and 100 patients were in the non-ICG group. More intracorporeal urinary diversions and more simple cystectomies were observed in the ICG group (p < 0.001 and p = 0.015, respectively). The ICG group patients initiated an oral diet sooner than the control group (4.9 vs. 7.1 days, p < 0.001). The mean length of stay of the ICG group was shorter than the non-ICG group (8.3 vs. 12.8 days, p < 0.001). The rate of postoperative ileus was not significantly different between cohorts. No patients in the ICG group experienced a bowel leak compared with five patients in the non-ICG group (p = 0.008). CONCLUSIONS: In our study, the use of ICG for intraoperative assessment of bowel and ureteric vascularity was associated with earlier bowel recovery and a shorter length of stay. It was also significantly correlated with a lower rate of anastomotic bowel leak.


Assuntos
Cistectomia , Verde de Indocianina , Procedimentos Cirúrgicos Robóticos , Derivação Urinária , Humanos , Verde de Indocianina/administração & dosagem , Cistectomia/efeitos adversos , Cistectomia/métodos , Derivação Urinária/métodos , Derivação Urinária/efeitos adversos , Masculino , Procedimentos Cirúrgicos Robóticos/efeitos adversos , Procedimentos Cirúrgicos Robóticos/métodos , Feminino , Pessoa de Meia-Idade , Idoso , Estudos Retrospectivos , Fístula Anastomótica/etiologia , Fístula Anastomótica/epidemiologia , Fístula Anastomótica/prevenção & controle , Neoplasias da Bexiga Urinária/cirurgia , Tempo de Internação/estatística & dados numéricos , Resultado do Tratamento , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/epidemiologia , Corantes/administração & dosagem
3.
Int Braz J Urol ; 50(2): 178-191, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38386788

RESUMO

INTRODUCTION: The increasing adoption of robotic-assisted cystectomy with intracorporeal urinary diversion (ICUD), despite its complexity, prompts a detailed comparison with extracorporeal urinary diversion (ECUD). Our study at a single institution investigates perioperative outcomes and identifies risk factors impacting the success of these surgical approaches. METHODS: In this retrospective analysis, 174 patients who underwent robotic-assisted cystectomy at the University of Louisville from June 2016 to August 2021 were reviewed. The cohort was divided into two groups based on the urinary diversion method: 30 patients underwent ECUD and 144 underwent ICUD. Data on demographics, complication rates, length of hospital stay, and readmission rates were meticulously collected and analyzed. RESULTS: Operative times were comparable between the ICUD and ECUD groups. However, the ICUD group had a significantly lower intraoperative transfusion rate (0.5 vs. 1.0, p=0.02) and shorter hospital stay (7.8 vs. 12.3 days, p<0.001). Factors such as male sex, smoking history, diabetes mellitus, intravesical therapy, higher ASA, and ACCI scores were associated with increased Clavien-Dindo Grade 3 or higher complications. Age over 70 was the sole factor linked to a higher 90-day readmission rate, with no specific characteristics influencing the 30-day rate. CONCLUSION: Robotic cystectomy with ICUD results in shorter hospitalizations and lower intraoperative transfusion rates compared to ECUD, without differences in operative time, high-grade postoperative complications, or readmission rates. These findings can inform clinical decision-making, highlighting ICUD as a potentially more favorable option in appropriate settings.


Assuntos
Procedimentos Cirúrgicos Robóticos , Derivação Urinária , Humanos , Masculino , Cistectomia/efeitos adversos , Estudos Retrospectivos , Procedimentos Cirúrgicos Robóticos/efeitos adversos , Derivação Urinária/efeitos adversos , Fatores de Risco
4.
World J Urol ; 41(9): 2413-2420, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37530808

RESUMO

OBJECTIVE: This research endeavored to determine the key demographic and pathological factors tied to secondary malignant neoplasms (SMNs) in survivors of testicular cancer and to develop a predictive model. METHOD: A total of 53,309 testicular cancer patients from the SEER national database (1975-2016) were included in our analysis. The primary outcome measured was SMNs-free survival, defined as the duration from testicular cancer diagnosis to the detection of a non-testicular malignancy. The secondary outcome was SMN-specific survival, defined as the period from testicular cancer diagnosis until the patient's death due to SMNs. FINDINGS: Of the patients in the SEER cohort, 2978 (5.6%) developed non-testicular cancer SMNs. Higher age, receipt of chemotherapy, and radiation treatment were all significantly associated with the development of SMNs in survivors of testicular cancer (all p < 0.001). Kaplan-Meier analysis revealed a worse SMNs-free survival and poor SMN-specific survival in patients who underwent radiation therapy (both p < 0.001). Multivariable Cox regression analysis found non-Hispanic Black ethnicity, higher age, chemotherapy, and radiation therapy to be significantly associated with worse SMNs-free survival (p = 0.002, p < 0.001, p < 0.001, and p < 0.001, respectively), while lymphoma histology was associated with better SMNs-free survival (p < 0.001). The most common SMN types in patients receiving radiation therapy were prostate, lung, and bladder cancers. Predictive nomograms for SMNs-free survival and SMNs-specific survival were developed, with a C-index of 0.776 and 0.824, respectively. CONCLUSION: The age of diagnosis, non-Hispanic Black ethnicity, lymphoma histology, and treatment history with chemotherapy and radiation therapy were identified as prognostic factors for SMNs-free survival.


Assuntos
Sobreviventes de Câncer , Segunda Neoplasia Primária , Neoplasias , Masculino , Humanos , Incidência , Segunda Neoplasia Primária/epidemiologia , Fatores de Risco , Sobreviventes , Neoplasias/complicações
5.
Am J Pathol ; 191(7): 1180-1192, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34000282

RESUMO

Hepatocellular carcinoma (HCC) is the fifth most common type of cancer and the third leading cause of cancer-related deaths worldwide. Liver resection or liver transplantation is the most effective therapy for HCC because drugs approved by the US Food and Drug Administration to treat patients with unresectable HCC have an unfavorable overall survival rate. Therefore, the development of biomarkers for early diagnosis and effective therapy strategies are still necessary to improve patient outcomes. Fibroblast growth factor (FGF) 19 was amplified in patients with HCC from various studies, including patients from The Cancer Genome Atlas. FGF19 plays a syngeneic function with other signaling pathways in primary liver cancer development, such as epidermal growth factor receptor, Wnt/ß-catenin, the endoplasmic reticulum-related signaling pathway, STAT3/IL-6, RAS, and extracellular signal-regulated protein kinase, among others. The current review presents a comprehensive description of the FGF19 signaling pathway involved in liver cancer development. The use of big data and bioinformatic analysis can provide useful clues for further studies of the FGF19 pathway in HCC, including its application as a biomarker, targeted therapy, and combination therapy strategies.


Assuntos
Carcinoma Hepatocelular/metabolismo , Fatores de Crescimento de Fibroblastos/metabolismo , Neoplasias Hepáticas/metabolismo , Animais , Biomarcadores Tumorais/metabolismo , Humanos , Transdução de Sinais/fisiologia
6.
PLoS Comput Biol ; 17(4): e1008792, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33819263

RESUMO

Pathway level understanding of cancer plays a key role in precision oncology. However, the current amount of high-throughput data cannot support the elucidation of full pathway topology. In this study, instead of directly learning the pathway network, we adapted the probabilistic OR gate to model the modular structure of pathways and regulon. The resulting model, OR-gate Network (ORN), can simultaneously infer pathway modules of somatic alterations, patient-specific pathway dysregulation status, and downstream regulon. In a trained ORN, the differentially expressed genes (DEGs) in each tumour can be explained by somatic mutations perturbing a pathway module. Furthermore, the ORN handles one of the most important properties of pathway perturbation in tumours, the mutual exclusivity. We have applied the ORN to lower-grade glioma (LGG) samples and liver hepatocellular carcinoma (LIHC) samples in TCGA and breast cancer samples from METABRIC. Both datasets have shown abnormal pathway activities related to immune response and cell cycles. In LGG samples, ORN identified pathway modules closely related to glioma development and revealed two pathways closely related to patient survival. We had similar results with LIHC samples. Additional results from the METABRIC datasets showed that ORN could characterize critical mechanisms of cancer and connect them to less studied somatic mutations (e.g., BAP1, MIR604, MICAL3, and telomere activities), which may generate novel hypothesis for targeted therapy.


Assuntos
Neoplasias/terapia , Humanos , Medicina de Precisão
7.
Bioinformatics ; 36(13): 4030-4037, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31913438

RESUMO

MOTIVATION: The matrix factorization is an important way to analyze coregulation patterns in transcriptomic data, which can reveal the tumor signal perturbation status and subtype classification. However, current matrix factorization methods do not provide clear bicluster structure. Furthermore, these algorithms are based on the assumption of linear combination, which may not be sufficient to capture the coregulation patterns. RESULTS: We presented a new algorithm for Boolean matrix factorization (BMF) via expectation maximization (BEM). BEM is more aligned with the molecular mechanism of transcriptomic coregulation and can scale to matrix with over 100 million data points. Synthetic experiments showed that BEM outperformed other BMF methods in terms of reconstruction error. Real-world application demonstrated that BEM is applicable to all kinds of transcriptomic data, including bulk RNA-seq, single-cell RNA-seq and spatial transcriptomic datasets. Given appropriate binarization, BEM was able to extract coregulation patterns consistent with disease subtypes, cell types or spatial anatomy. AVAILABILITY AND IMPLEMENTATION: Python source code of BEM is available on https://github.com/LifanLiang/EM_BMF. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Biologia Computacional , Transcriptoma , Algoritmos , Software , Sequenciamento do Exoma
8.
Circ Res ; 123(6): 673-685, 2018 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-30355233

RESUMO

RATIONALE: Abnormal SUMOylation has emerged as a characteristic of heart failure (HF) pathology. Previously, we found reduced SUMO1 (small ubiquitin-like modifier 1) expression and SERCA2a (sarcoplasmic reticulum Ca2+-ATPase) SUMOylation in human and animal HF models. SUMO1 gene delivery or small molecule activation of SUMOylation restored SERCA2a SUMOylation and cardiac function in HF models. Despite the critical role of SUMO1 in HF, the regulatory mechanisms underlying SUMO1 expression are largely unknown. OBJECTIVE: To examine miR-146a-mediated SUMO1 regulation and its consequent effects on cardiac morphology and function. METHODS AND RESULTS: In this study, miR-146a was identified as a SUMO1-targeting microRNA in the heart. A strong correlation was observed between miR-146a and SUMO1 expression in failing mouse and human hearts. miR-146a was manipulated in cardiomyocytes through AAV9 (adeno-associated virus serotype 9)-mediated gene delivery, and cardiac morphology and function were analyzed by echocardiography and hemodynamics. Overexpression of miR-146a reduced SUMO1 expression, SERCA2a SUMOylation, and cardiac contractility in vitro and in vivo. The effects of miR-146a inhibition on HF pathophysiology were examined by transducing a tough decoy of miR-146a into mice subjected to transverse aortic constriction. miR-146a inhibition improved cardiac contractile function and normalized SUMO1 expression. The regulatory mechanisms of miR-146a upregulation were elucidated by examining the major miR-146a-producing cell types and transfer mechanisms. Notably, transdifferentiation of fibroblasts triggered miR-146a overexpression and secretion through extracellular vesicles, and the extracellular vesicle-associated miR-146a transfer was identified as the causative mechanism of miR-146a upregulation in failing cardiomyocytes. Finally, extracellular vesicles isolated from failing hearts were shown to contain high levels of miR-146a and exerted negative effects on the SUMO1/SERCA2a signaling axis and hence cardiomyocyte contractility. CONCLUSIONS: Taken together, our results show that miR-146a is a novel regulator of the SUMOylation machinery in the heart, which can be targeted for therapeutic intervention.


Assuntos
Cardiomegalia/metabolismo , Insuficiência Cardíaca/metabolismo , MicroRNAs/metabolismo , Contração Miocárdica , Miócitos Cardíacos/metabolismo , Proteína SUMO-1/metabolismo , Animais , Cardiomegalia/genética , Cardiomegalia/patologia , Cardiomegalia/fisiopatologia , Comunicação Celular , Transdiferenciação Celular , Células Cultivadas , Modelos Animais de Doenças , Regulação para Baixo , Fibroblastos/metabolismo , Fibroblastos/patologia , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/patologia , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Camundongos , MicroRNAs/genética , Miócitos Cardíacos/patologia , Proteína SUMO-1/genética , Transdução de Sinais , Sumoilação
9.
BMC Bioinformatics ; 20(1): 225, 2019 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-31046665

RESUMO

BACKGROUND: Characterizing the modular structure of cellular network is an important way to identify novel genes for targeted therapeutics. This is made possible by the rising of high-throughput technology. Unfortunately, computational methods to identify functional modules were limited by the data quality issues of high-throughput techniques. This study aims to integrate knowledge extracted from literature to further improve the accuracy of functional module identification. RESULTS: Our new model and algorithm were applied to both yeast and human interactomes. Predicted functional modules have covered over 90% of the proteins in both organisms, while maintaining a comparable overall accuracy. We found that the combination of both mRNA expression information and biomedical knowledge greatly improved the performance of functional module identification, which is better than those only using protein interaction network weighted with transcriptomic data, literature knowledge, or simply unweighted protein interaction network. Our new algorithm also achieved better performance when comparing with some other well-known methods, especially in terms of the positive predictive value (PPV), which indicated the confidence of novel discovery. CONCLUSION: Higher PPV with the multiplex approach suggested that information from both sources has been effectively integrated to reduce false positive. With protein coverage higher than 90%, our algorithm is able to generate more novel biological hypothesis with higher confidence.


Assuntos
Algoritmos , Mapeamento de Interação de Proteínas/métodos , Análise por Conglomerados , Perfilação da Expressão Gênica , Genes Fúngicos , Humanos , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
10.
Am J Respir Cell Mol Biol ; 61(2): 244-256, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30742487

RESUMO

Primary graft dysfunction (PGD) is a major cause of morbidity and mortality after lung transplantation. Ischemia-reperfusion injury (IRI) is a key event that contributes to PGD, though complex interactions affect donor lungs status, such as preceding brain death (BD), hemorrhagic shock (HS), and pre-engraftment lung management, the latter recognized as important risk factors for PGD. We hypothesized that a multi-hit isogenic mouse model of lung transplantation is more closely linked to PGD than IRI alone. Left lung transplants were performed between inbred C57BL/6 mice. A one-hit model of IRI was established by inducing cold ischemia (CI) of the donor lungs at 0°C for 1, 72, or 96 hours before engraftment. Multi-hit models were established by inducing 24 hours of HS and/or 3 hours of BD before 24 hours of CI. The recipients were killed at 24 hours after transplant and lung graft samples were analyzed. In the one-hit model of IRI, up to 72-hour CI time resulted in minimal cellular infiltration near small arteries after 24-hour reperfusion. Extension of CI time to 96 hours led to increased cellular infiltration and necroptotic pathway activation, without evidence of apoptosis, after 24-hour reperfusion. In a multi-hit model of PGD, "HS + BD + IRI" demonstrated increased lung injury, cellular infiltration, and activation of necroptotic and apoptotic pathways compared with IRI alone. Treatment with an inhibitor of receptor-interacting protein kinase 1 kinase, necrostatin-1, resulted in a significant decrease of downstream necroptotic pathway activation in both single- and multi-hit models of IRI. Thus, activation of necroptosis is a central event in IRI after prolonged CI, though it may not be sufficient to cause PGD alone. Pathological evaluation of donor lungs after CI-induced IRI, in conjunction with pre-engraftment donor lung factors in our multi-hit model, demonstrated early evidence of lung injury consistent with PGD. Our findings support the premise that pre-existing donor lung status is more important than CI time alone for inflammatory pathway activation in PGD, which may have important clinical implications for donor lung retrieval.


Assuntos
Apoptose , Isquemia Fria , Transplante de Pulmão/efeitos adversos , Pulmão/patologia , Necrose , Disfunção Primária do Enxerto/patologia , Traumatismo por Reperfusão/patologia , Animais , Morte Encefálica , Morte Celular , Modelos Animais de Doenças , Imidazóis/metabolismo , Indóis/metabolismo , Lesão Pulmonar/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Permeabilidade , Testes de Função Respiratória , Fatores de Risco , Análise de Sequência de RNA , Choque Hemorrágico , Transdução de Sinais
11.
Am J Physiol Heart Circ Physiol ; 317(1): H63-H72, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31074653

RESUMO

The aim of the present study was to develop and study a new model of left atrial thrombus (LAT) in rat with congestive heart failure (CHF). CHF was induced by aortic banding for 2 mo, followed by ischemia-reperfusion (I/R) and subsequent aortic debanding for 1 mo. Cardiac function and the presence of LAT were assessed by echocardiography. Masson's staining was performed for histological analysis. All CHF rats presented with significantly decreased cardiac function, fibrosis in remote myocardium, and pulmonary edema. The incidence rate of LAT was 18.8% in the rats. LAT was associated with severity of aortic constriction, aortic pressure gradient, aortic blood flow velocity, and pulmonary edema but not myocardial infarction or a degree of left ventricular depression. The progressive process of thrombogenesis was characterized by myocyte hypertrophy, fibrosis, and inflammation in the left atrial wall. Fibrin adhesion and clot formation were observed, whereas most LAT presented as a relatively hard "mass," likely attributable to significant fibrosis in the middle and outer layers. Some LAT mass showed focal necrosis as well as fibrin bulging. Most LAT occurred at the upper anterior wall of the left atrial appendage. Aortic debanding had no significant impact on large LATs (>5 mm2) that had formed, whereas small LATs (<5 mm2) regressed 1 mo after aortic release. LAT is found in a rat model of aortic banding plus I/R followed by aortic debanding. The model provides a platform to study molecular mechanisms and potential new pathways for LAT treatment. NEW & NOTEWORTHY It is critically important to have a rodent model to study the molecular mechanism of thrombogenesis in the left atrium. Left atrial thrombus (LAT) is not a simple fibrin clot like those seen in peripheral veins or arteries. Rather, LAT is a cellular mass that likely develops in conjunction with blood clotting. Studying this phenomenon will help us understand congestive heart failure and promote new therapies for LAT.


Assuntos
Aorta/cirurgia , Vasos Coronários/cirurgia , Átrios do Coração/patologia , Insuficiência Cardíaca/etiologia , Traumatismo por Reperfusão Miocárdica/etiologia , Técnicas de Sutura , Trombose/complicações , Animais , Aorta/fisiopatologia , Função do Átrio Esquerdo , Remodelamento Atrial , Coagulação Sanguínea , Vasos Coronários/fisiopatologia , Modelos Animais de Doenças , Progressão da Doença , Fibrose , Átrios do Coração/fisiopatologia , Insuficiência Cardíaca/patologia , Insuficiência Cardíaca/fisiopatologia , Hemodinâmica , Ligadura , Masculino , Traumatismo por Reperfusão Miocárdica/patologia , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Ratos Sprague-Dawley , Trombose/sangue , Trombose/patologia , Trombose/fisiopatologia , Fatores de Tempo
12.
Am J Physiol Heart Circ Physiol ; 313(2): H275-H282, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28550174

RESUMO

Low reliability and reproducibility in heart failure models are well established. The purpose of the present study is to explore factors that affect model consistency of myocardial infarction (MI) in mice. MI was induced by left coronary artery (LCA) ligation. The coronary artery was casted with resin and visualized with fluorescent imaging ex vivo. LCA characteristics and MI size were analyzed individually in each animal, and MI size was correlated with left ventricular (LV) function by echocardiography. Coronary anatomy varies widely in mice, posing challenges for surgical ligation and resulting in inconsistent MI size postligation. The length of coronary arterial trunk, level of bifurcation, number of branches, and territory supplied by these branches are unique in each animal. When the main LCA trunk is ligated, this results in a large MI, but when a single branch is ligated, MI size is variable due to differing levels of LCA ligation and area supplied by the branches. During the ligation procedure, nearly 40% of LCAs are not grossly visible to the surgeon. In these situations, the surgeon blindly sutures a wider and deeper area of tissue in an attempt to catch the LCA. Paradoxically, these situations have greater odds of resulting in smaller MIs. In conclusion, variation in MI size and LV function after LCA ligation in mice is difficult to avoid. Anatomic diversity of the LCA in mice leads to inconsistency in MI size and functional parameters, and this is independent of potential technical modifications made by the operator.NEW & NOTEWORTHY In the present study, we demonstrate that left coronary artery diversity in mice is one of the primary causes of variable myocardial infarction size and cardiac functional parameters in the left coronary artery ligation model. Recognition of anatomic diversity is essential to improve reliability and reproducibility in heart failure research.


Assuntos
Anomalias dos Vasos Coronários/complicações , Vasos Coronários/patologia , Infarto do Miocárdio/patologia , Miocárdio/patologia , Animais , Anomalias dos Vasos Coronários/patologia , Anomalias dos Vasos Coronários/fisiopatologia , Vasos Coronários/fisiopatologia , Vasos Coronários/cirurgia , Modelos Animais de Doenças , Ligadura , Masculino , Camundongos Endogâmicos C57BL , Infarto do Miocárdio/etiologia , Infarto do Miocárdio/fisiopatologia , Imagem Óptica , Fenótipo , Técnicas de Réplica , Volume Sistólico , Função Ventricular Esquerda
13.
Biochim Biophys Acta ; 1853(11 Pt A): 2870-84, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26260012

RESUMO

The importance of the oncogene Ras in cardiac hypertrophy is well appreciated. The hypertrophic effects of the constitutively active mutant Ras-Val12 are revealed by clinical syndromes due to the Ras mutations and experimental studies. We examined the possible anti-hypertrophic effect of Ras inhibition in vitro using rat neonatal cardiomyocytes (NRCM) and in vivo in the setting of pressure-overload left ventricular (LV) hypertrophy (POH) in rats. Ras functions were modulated via adenovirus directed gene transfer of active mutant Ras-Val12 or dominant negative mutant N17-DN-Ras (DN-Ras). Ras-Val12 expression in vitro activates NFAT resulting in pro-hypertrophic and cardio-toxic effects on NRCM beating and Z-line organization. In contrast, the DN-Ras was antihypertrophic on NRCM, inhibited NFAT and exerted cardio-protective effects attested by preserved NRCM beating and Z line structure. Additional experiments with silencing H-Ras gene strategy corroborated the antihypertrophic effects of siRNA-H-Ras on NRCM. In vivo, with the POH model, both Ras mutants were associated with similar hypertrophy two weeks after simultaneous induction of POH and Ras-mutant gene transfer. However, LV diameters were higher and LV fractional shortening lower in the Ras-Val12 group compared to control and DN-Ras. Moreover, DN-Ras reduced the cross-sectional area of cardiomyocytes in vivo, and decreased the expression of markers of pathologic cardiac hypertrophy. In isolated adult cardiomyocytes after 2 weeks of POH and Ras-mutant gene transfer, DN-Ras improved sarcomere shortening and calcium transients compared to Ras-Val12. Overall, DN-Ras promotes a more physiological form of hypertrophy, suggesting an interesting therapeutic target for pathological cardiac hypertrophy.


Assuntos
Cardiomegalia/enzimologia , Mutação de Sentido Incorreto , Miocárdio/enzimologia , Miócitos Cardíacos/enzimologia , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Remodelação Ventricular , Substituição de Aminoácidos , Animais , Cardiomegalia/genética , Cardiomegalia/patologia , Miocárdio/patologia , Miócitos Cardíacos/patologia , Ratos , Ratos Sprague-Dawley , Sarcômeros/enzimologia , Sarcômeros/genética
14.
Circulation ; 129(7): 773-85, 2014 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-24249716

RESUMO

BACKGROUND: Phenotypic modulation or switching of vascular smooth muscle cells from a contractile/quiescent to a proliferative/synthetic phenotype plays a key role in vascular proliferative disorders such as atherosclerosis and restenosis. Although several calcium handling proteins that control differentiation of smooth muscle cells have been identified, the role of protein phosphatase inhibitor 1 (I-1) in the acquisition or maintenance of the contractile phenotype modulation remains unknown. METHODS AND RESULTS: In human coronary arteries, I-1 and sarco/endoplasmic reticulum Ca2+ -ATPase expression is specific to contractile vascular smooth muscle cells. In synthetic cultured human coronary artery smooth muscle cells, protein phosphatase inhibitor 1 (I-1 target) is highly expressed, leading to a decrease in phospholamban phosphorylation, sarco/endoplasmic reticulum Ca2+ -ATPase, and cAMP-responsive element binding activity. I-1 knockout mice lack phospholamban phosphorylation and exhibit vascular smooth muscle cell arrest in the synthetic state with excessive neointimal proliferation after carotid injury, as well as significant modifications of contractile properties and relaxant response to acetylcholine of femoral artery in vivo. Constitutively active I-1 gene transfer decreased neointimal formation in an angioplasty rat model by preventing vascular smooth muscle cell contractile to synthetic phenotype change. CONCLUSIONS: I-1 and sarco/endoplasmic reticulum Ca2+ -ATPase synergistically induce the vascular smooth muscle cell contractile phenotype. Gene transfer of constitutively active I-1 is a promising therapeutic strategy for preventing vascular proliferative disorders.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Músculo Liso Vascular/metabolismo , Proteína Fosfatase 1/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , Vasoconstrição/fisiologia , Animais , Aorta Torácica/citologia , Aorta Torácica/fisiologia , Sinalização do Cálcio/fisiologia , Vasos Coronários/citologia , Vasos Coronários/fisiologia , Artéria Femoral/citologia , Artéria Femoral/fisiologia , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Masculino , Artéria Torácica Interna/citologia , Artéria Torácica Interna/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Músculo Liso Vascular/citologia , Fenótipo , Proteína Fosfatase 1/genética , Proteínas/genética , Proteínas/metabolismo , Ratos , Ratos Sprague-Dawley , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/genética , Doenças Vasculares/genética , Doenças Vasculares/metabolismo
15.
Am J Physiol Heart Circ Physiol ; 308(8): H830-40, 2015 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-25659485

RESUMO

The aim of the present study is to explore the role of capillary disorder in coronary ischemic congestive heart failure (CHF). CHF was induced in rats by aortic banding plus ischemia-reperfusion followed by aortic debanding. Coronary arteries were perfused with plastic polymer containing fluorescent dye. Multiple fluorescent images of casted heart sections and scanning electric microscope of coronary vessels were obtained to characterize changes in the heart. Cardiac function was assessed by echocardiography and in vivo hemodynamics. Stenosis was found in all levels of the coronary arteries in CHF. Coronary vasculature volume and capillary density in remote myocardium were significantly increased in CHF compared with control. This occurred largely in microvessels with a diameter of ≤3 µm. Capillaries in CHF had a tortuous structure, while normal capillaries were linear. Capillaries in CHF had inconsistent diameters, with assortments of narrowed and bulged segments. Their surfaces appeared rough, potentially indicating endothelial dysfunction in CHF. Segments of main capillaries between bifurcations were significantly shorter in length in CHF than in control. Transiently increasing preload by injecting 50 µl of 30% NaCl demonstrated that the CHF heart had lower functional reserve; this may be associated with congestion in coronary microcirculation. Ischemic coronary vascular disorder is not limited to the main coronary arteries, as it occurs in arterioles and capillaries. Capillary disorder in CHF included stenosis, deformed structure, proliferation, and roughened surfaces. This disorder in the coronary artery architecture may contribute to the reduction in myocyte contractility in the setting of heart failure.


Assuntos
Capilares/patologia , Vasos Coronários/patologia , Insuficiência Cardíaca/patologia , Traumatismo por Reperfusão Miocárdica/patologia , Animais , Capilares/fisiopatologia , Estenose Coronária/patologia , Estenose Coronária/fisiopatologia , Vasos Coronários/fisiopatologia , Reserva Fracionada de Fluxo Miocárdico , Insuficiência Cardíaca/fisiopatologia , Masculino , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Ratos , Ratos Sprague-Dawley
16.
Circulation ; 128(5): 512-23, 2013 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-23804254

RESUMO

BACKGROUND: Pulmonary arterial hypertension (PAH) is characterized by dysregulated proliferation of pulmonary artery smooth muscle cells leading to (mal)adaptive vascular remodeling. In the systemic circulation, vascular injury is associated with downregulation of sarcoplasmic reticulum Ca(2+)-ATPase 2a (SERCA2a) and alterations in Ca(2+) homeostasis in vascular smooth muscle cells that stimulate proliferation. We, therefore, hypothesized that downregulation of SERCA2a is permissive for pulmonary vascular remodeling and the development of PAH. METHODS AND RESULTS: SERCA2a expression was decreased significantly in remodeled pulmonary arteries from patients with PAH and the rat monocrotaline model of PAH in comparison with controls. In human pulmonary artery smooth muscle cells in vitro, SERCA2a overexpression by gene transfer decreased proliferation and migration significantly by inhibiting NFAT/STAT3. Overexpresion of SERCA2a in human pulmonary artery endothelial cells in vitro increased endothelial nitric oxide synthase expression and activation. In monocrotaline rats with established PAH, gene transfer of SERCA2a via intratracheal delivery of aerosolized adeno-associated virus serotype 1 (AAV1) carrying the human SERCA2a gene (AAV1.SERCA2a) decreased pulmonary artery pressure, vascular remodeling, right ventricular hypertrophy, and fibrosis in comparison with monocrotaline-PAH rats treated with a control AAV1 carrying ß-galactosidase or saline. In a prevention protocol, aerosolized AAV1.SERCA2a delivered at the time of monocrotaline administration limited adverse hemodynamic profiles and indices of pulmonary and cardiac remodeling in comparison with rats administered AAV1 carrying ß-galactosidase or saline. CONCLUSIONS: Downregulation of SERCA2a plays a critical role in modulating the vascular and right ventricular pathophenotype associated with PAH. Selective pulmonary SERCA2a gene transfer may offer benefit as a therapeutic intervention in PAH.


Assuntos
Hipertensão Pulmonar/terapia , Monocrotalina/toxicidade , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/genética , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/uso terapêutico , Animais , Células Cultivadas , Modelos Animais de Doenças , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Hipertensão Pulmonar Primária Familiar , Técnicas de Transferência de Genes , Células HEK293 , Ventrículos do Coração/metabolismo , Ventrículos do Coração/patologia , Humanos , Hipertensão Pulmonar/induzido quimicamente , Hipertensão Pulmonar/enzimologia , Masculino , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/metabolismo , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/biossíntese , Resultado do Tratamento
17.
Circ Res ; 111(11): 1434-45, 2012 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-22931954

RESUMO

RATIONALE: There is growing evidence that the myocardium responds to injury by recruiting c-kit(+) cardiac progenitor cells to the damage tissue. Even though the ability of exogenously introducing c-kit(+) cells to injured myocardium has been established, the capability of recruiting these cells through modulation of local signaling pathways by gene transfer has not been tested. OBJECTIVE: To determine whether stem cell factor gene transfer mediates cardiac regeneration in a rat myocardial infarction model, through survival and recruitment of c-kit(+) progenitors and cell-cycle activation in cardiomyocytes, and explore the mechanisms involved. METHODS AND RESULTS: Infarct size, cardiac function, cardiac progenitor cells recruitment, fibrosis, and cardiomyocyte cell-cycle activation were measured at different time points in controls (n=10) and upon stem cell factor gene transfer (n=13) after myocardial infarction. We found a regenerative response because of stem cell factor overexpression characterized by an enhancement in cardiac hemodynamic function: an improvement in survival; a reduction in fibrosis, infarct size and apoptosis; an increase in cardiac c-kit(+) progenitor cells recruitment to the injured area; an increase in cardiomyocyte cell-cycle activation; and Wnt/ß-catenin pathway induction. CONCLUSIONS: Stem cell factor gene transfer induces c-kit(+) stem/progenitor cell expansion in situ and cardiomyocyte proliferation, which may represent a new therapeutic strategy to reverse adverse remodeling after myocardial infarction.


Assuntos
Proliferação de Células , Infarto do Miocárdio/terapia , Miocárdio/metabolismo , Proteínas Proto-Oncogênicas c-kit/metabolismo , Fator de Células-Tronco/metabolismo , Adenoviridae/genética , Animais , Western Blotting , Contagem de Células , Expressão Gênica , Terapia Genética/métodos , Humanos , Estimativa de Kaplan-Meier , Masculino , Microscopia Confocal , Infarto do Miocárdio/genética , Infarto do Miocárdio/fisiopatologia , Miocárdio/patologia , Miócitos Cardíacos/metabolismo , Ratos , Ratos Sprague-Dawley , Regeneração , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Células-Tronco/genética , Células-Tronco/metabolismo , Via de Sinalização Wnt/genética , beta Catenina/genética , beta Catenina/metabolismo
18.
J Glob Health ; 14: 04007, 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38334270

RESUMO

Background: Japan has implemented a national lifestyle guidance intervention programme for potential metabolic syndrome among adults aged 40-74 years; however, there is limited evidence regarding the causal impact of this intervention. The study aims to determine the causal effect of this intervention on health outcomes and health care utilisation. Methods: We performed a regression discontinuity design study. A total of 46 975 adults with ≥1 cardiovascular risk factor in 2015 were included in the study. A two-stage evaluation process (stage 1: waist circumference ≥85 cm for men or ≥90 cm for women and ≥1 cardiovascular risk factor; stage 2: body mass index (BMI)≥25 kg/m2 and ≥2 cardiovascular risk factors) was applied. Changes in obesity, cardiovascular outcomes, and health care utilisation were evaluated in a one-year follow-up in the fiscal year 2016. Results: Participants who received lifestyle guidance intervention based on the waist circumference had a statistically significant reduction in obesity outcomes (Δ weight: -0.30 kg, 95% CI = -0.46 to -0.11; Δ waist circumference: -0.26 cm, 95% CI = -0.53 to -0.02; Δ BMI = -0.09 kg/m2, 95% CI = -0.17 to -0.04) but not in other cardiovascular risk factors and health care utilisation. Analyses based on BMI and results according to demographic subgroups did not reveal significant findings. Conclusions: The provision of this intervention had a limited effect on health improvement and a decrease in health care costs, health care visits, and length of stay. A more intensive intervention delivery could potentially improve the efficacy of this intervention programme.


Assuntos
Síndrome Metabólica , Adulto , Pessoa de Meia-Idade , Masculino , Humanos , Feminino , Síndrome Metabólica/epidemiologia , Síndrome Metabólica/prevenção & controle , Japão/epidemiologia , Obesidade , Índice de Massa Corporal , Estilo de Vida
19.
Int J Biol Macromol ; 262(Pt 2): 130099, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38342255

RESUMO

The study aimed to assay the allergenicity of shrimp tropomyosin (TM) following covalent conjugation with quercetin (QR) and chlorogenic acid (CA). The structure of the TM-polyphenol covalent conjugates was examined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), circular dichroism (CD), fluorescence, differential scanning calorimetry (DSC), and Fourier Transform infrared spectroscopy (FTIR). Potential allergenicity was evaluated using in vitro and in vivo methods. The results showed that QR and CA induced structural changes in TM through aggregation. RBL-2H3 cell results showed that TM-QR and TM-CA covalent conjugates reduced the release of ß-hexosaminidase and histamine, respectively. In the mice model, TM-QR and TM-CA covalent conjugates reduced the level of IgE, IgG, IgG1, histamine, and mMCP-1 in sera. Furthermore, the allergenicity was reduced by suppressing Th2-related cytokines (IL-4, IL-5, IL-13) and promoting Th1-related cytokines (IFN-γ). These research findings demonstrate that the covalent binding of TM with QR and CA, modifies the allergenic epitopes of shrimp TM, thereby reducing its potential allergenicity. This approach holds practical applications in the production of low-allergenicity food within the food industry.


Assuntos
Alérgenos , Tropomiosina , Camundongos , Animais , Tropomiosina/química , Alérgenos/química , Ácido Clorogênico/química , Quercetina , Histamina , Imunoglobulina E/metabolismo , Citocinas
20.
Am J Physiol Heart Circ Physiol ; 304(5): H719-28, 2013 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-23275620

RESUMO

This study investigates the impact of pressure overload on vascular changes after myocardial infarction (MI) in rats. To evaluate the effect of pressure overload, MI was induced in three groups: 1) left coronary artery ligation for 1 mo (MI-1m), 2) ischemia 30 min/reperfusion for 1 mo (I/R-1m), and 3) ischemia-reperfusion (I/R) was performed after pressure overload induced by aortic banding for 2 mo; 1 mo post-I/R, aortic constriction was released (Ab+I/R+DeAb). Heart function was assessed by echocardiography and in vivo hemodynamics. Resin casting and three-dimensional imaging with microcomputed tomography were used to characterize changes in coronary vasculature. TTC (triphenyltetrazohum chloride) staining and Masson's Trichrome were conducted in parallel experiments. In normal rats, MI induced by I/R and permanent occlusion was transmural or subendocardial. Occluded arterial branches vanished in MI-1m rats. A short residual tail was retained, distal to the occluded site in the ischemic area in I/R-1m hearts. Vascular pathological changes in transmural MI mostly occurred in ischemic areas and remote vasculature remained normal. In pressure overloaded rats, I/R injury induced a sub-MI in which ischemia was transmural, but myocardium in the involved area had survived. The ischemic arterial branches were preserved even though the capillaries were significantly diminished and the pathological changes were extended to remote areas, characterized by fibrosis, atrial thrombus, and pulmonary edema in the Ab+I/R+DeAb group. Pressure overload could increase vascular tolerance to I/R injury, but also trigger severe global ventricular fibrosis and results in atrial thrombus and pulmonary edema.


Assuntos
Circulação Coronária/fisiologia , Vasos Coronários/fisiologia , Insuficiência Cardíaca/fisiopatologia , Infarto do Miocárdio/fisiopatologia , Pressão Ventricular/fisiologia , Animais , Capilares/diagnóstico por imagem , Capilares/fisiologia , Técnicas de Imagem Cardíaca , Vasos Coronários/diagnóstico por imagem , Modelos Animais de Doenças , Ecocardiografia , Fibrose/diagnóstico , Fibrose/fisiopatologia , Insuficiência Cardíaca/diagnóstico , Masculino , Infarto do Miocárdio/diagnóstico , Traumatismo por Reperfusão Miocárdica/diagnóstico , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Miocárdio/patologia , Ratos , Ratos Sprague-Dawley , Tomografia Computadorizada por Raios X
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa