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1.
EMBO J ; 42(14): e112845, 2023 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-37272163

RESUMO

The canonical autophagy pathway in mammalian cells sequesters diverse cytoplasmic cargo within the double membrane autophagosomes that eventually convert into degradative compartments via fusion with endolysosomal intermediates. Here, we report that autophagosomal membranes show permeability in cells lacking principal ATG8 proteins (mATG8s) and are unable to mature into autolysosomes. Using a combination of methods including a novel in vitro assay to measure membrane sealing, we uncovered a previously unappreciated function of mATG8s to maintain autophagosomal membranes in a sealed state. The mATG8 proteins GABARAP and LC3A bind to key ESCRT-I components contributing, along with other ESCRTs, to the integrity and imperviousness of autophagic membranes. Autophagic organelles in cells lacking mATG8s are permeant, are arrested as amphisomes, and do not progress to functional autolysosomes. Thus, autophagosomal organelles need to be maintained in a sealed state in order to become lytic autolysosomes.


Assuntos
Autofagia , Proteínas Associadas aos Microtúbulos , Animais , Humanos , Família da Proteína 8 Relacionada à Autofagia/genética , Família da Proteína 8 Relacionada à Autofagia/metabolismo , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Autofagossomos/metabolismo , Complexos Endossomais de Distribuição Requeridos para Transporte/metabolismo , Mamíferos
2.
J Am Chem Soc ; 146(10): 7052-7062, 2024 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-38427585

RESUMO

Functional DNAs are valuable molecular tools in chemical biology and analytical chemistry but suffer from low activities due to their limited chemical functionalities. Here, we present a chemoenzymatic method for site-specific installation of diverse functional groups on DNA, and showcase the application of this method to enhance the catalytic activity of a DNA catalyst. Through chemoenzymatic introduction of distinct chemical groups, such as hydroxyl, carboxyl, and benzyl, at specific positions, we achieve significant enhancements in the catalytic activity of the RNA-cleaving deoxyribozyme 10-23. A single carboxyl modification results in a 100-fold increase, while dual modifications (carboxyl and benzyl) yield an approximately 700-fold increase in activity when an RNA cleavage reaction is catalyzed on a DNA-RNA chimeric substrate. The resulting dually modified DNA catalyst, CaBn, exhibits a kobs of 3.76 min-1 in the presence of 1 mM Mg2+ and can be employed for fluorescent imaging of intracellular magnesium ions. Molecular dynamics simulations reveal the superior capability of CaBn to recruit magnesium ions to metal-ion-binding site 2 and adopt a catalytically competent conformation. Our work provides a broadly accessible strategy for DNA functionalization with diverse chemical modifications, and CaBn offers a highly active DNA catalyst with immense potential in chemistry and biotechnology.


Assuntos
DNA Catalítico , RNA Catalítico , Sequência de Bases , Magnésio , DNA Catalítico/química , DNA , RNA/química , Íons , Conformação de Ácido Nucleico , Catálise , RNA Catalítico/metabolismo
3.
Small ; 19(49): e2302939, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37496086

RESUMO

Microbubble generation and manipulation play critical roles in diverse applications such as microfluidic mixing, pumping, and microrobot propulsion. However, existing methods are typically limited to lateral movements on customized substrates or rely on specific liquids with particular properties or designed concentration gradients, thereby hindering their practical applications. To address this challenge, this paper presents a method that enables robust vertical manipulation of microbubbles. By focusing a resonant laser on hydrophilic silica-coated gold nanoparticle arrays immersed in water, plasmonic microbubbles are generated and detach from the substrates immediately upon cessation of laser irradiation. Using simple laser pulse control, it can achieve an adjustable size and frequency of bubble bouncing, which is governed by the movement of the three-phase contact line during surface wetting. Furthermore, it demonstrates that rising bubbles can be pulled back by laser irradiation induced thermal Marangoni flow, which is verified by particle image velocimetry measurements and numerical simulations. This study provides novel insights into flexible bubble manipulation and integration in microfluidics, with significant implications for various applications including mixing, drug delivery, and the development of soft actuators.

4.
Cancer Invest ; 39(1): 62-72, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33258714

RESUMO

To dissect gene expression subgroups of FOLFOX resistance colorectal cancer(CRC) and predict FOLFOX response, gene expression data of 83 stage IV CRC tumor samples (FOLFOX responder n = 42, non-responder n = 41) are used to develop a novel iterative supervised learning method IML. IML identified two mutually exclusive subgroups of CRC patients that rely on different DNA damage repair proteins and resist FOLFOX. IML was validated in two validation sets (HR = 2.6, p Value = 0.02; HR = 2.36, p value = 0.02). A subgroup of mesenchymal subtype patients benefit from FOLFOX. Different subgroups of FOLFOX nonresponders may need to be treated differently.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Colorretais/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Feminino , Fluoruracila/farmacologia , Fluoruracila/uso terapêutico , Humanos , Leucovorina/farmacologia , Leucovorina/uso terapêutico , Masculino , Compostos Organoplatínicos/farmacologia , Compostos Organoplatínicos/uso terapêutico
5.
Sensors (Basel) ; 21(19)2021 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-34640659

RESUMO

For an airborne passive radar with contaminated reference signals, the clutter caused by multipath (MP) signals involved in the reference channel (MP clutter) corrupts the covariance estimation in space-time adaptive processing (STAP). In order to overcome the severe STAP performance degradation caused by impure reference signals and off-grid effects, a novel MP clutter suppression method based on local search is proposed for airborne passive radar. In the proposed method, the global dictionary is constructed based on the sparse measurement model of MP clutter, and the global atoms that are most relevant to the residual are selected. Then, the local dictionary is designed iteratively, and local searches are performed to match real MP clutter points. Finally, the off-grid effects are mitigated, and the MP clutter is suppressed from all matched atoms. A range of simulations is conducted in order to demonstrate the effectiveness of the proposed method.


Assuntos
Algoritmos , Sistemas Computacionais , Radar
6.
J Mol Cell Cardiol ; 131: 29-40, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31004678

RESUMO

Although cancer cells use heparanase for tumor metastasis, favourable effects of heparanase have been reported in the management of Alzheimer's disease and diabetes. Indeed, we previously established a protective function for heparanase in the acutely diabetic heart, where it conferred cardiomyocyte resistance to oxidative stress and apoptosis by provoking changes in gene expression. In this study, we tested if overexpression of heparanase can protect the heart against chemically induced or ischemia/reperfusion (I/R) injury. Transcriptomic analysis of Hep-tg hearts reveal that 240 genes related to the stress response, immune response, cell death, and development were altered in a pro-survival direction encompassing genes promoting the unfolded protein response (UPR) and autophagy, as well as those protecting against oxidative stress. The observed UPR activation was adaptive and not apoptotic, was mediated by activation of ATF6α, and when combined with mTOR inhibition, induced autophagy. Subjecting wild type (WT) mice to increasing concentrations of the ER stress inducer thapsigargin evoked a transition from adaptive to apoptotic UPR, an effect that was attenuated in Hep-tg mouse hearts. Consistent with these observations, when exposed to I/R, the infarct size and markers of apoptosis were significantly lower in the Hep-tg heart compared to WT. Finally, UPR and autophagy inhibitors reduced the protective effects of heparanase overexpression during I/R. Our data suggest that the mechanisms that underlie the role of heparanase in promoting cell survival could be uniquely beneficial to the heart by providing protection against cellular stresses, and could be useful for exploitation as a therapeutic target for the treatment of heart disease.


Assuntos
Glucuronidase/metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , Substâncias Protetoras/metabolismo , Animais , Apoptose/fisiologia , Autofagia/fisiologia , Sobrevivência Celular/fisiologia , Coração/fisiologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Ratos , Ratos Wistar , Tapsigargina/metabolismo , Resposta a Proteínas não Dobradas/fisiologia
7.
Am J Physiol Heart Circ Physiol ; 314(1): H82-H94, 2018 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-28986359

RESUMO

In the diabetic heart, there is excessive dependence on fatty acid (FA) utilization to generate ATP. Lipoprotein lipase (LPL)-mediated hydrolysis of circulating triglycerides is suggested to be the predominant source of FA for cardiac utilization during diabetes. In the heart, the majority of LPL is synthesized in cardiomyocytes and secreted onto cell surface heparan sulfate proteoglycan (HSPG), where an endothelial cell (EC)-releasable ß-endoglycosidase, heparanase cleaves the side chains of HSPG to liberate LPL for its onward movement across the EC. EC glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 (GPIHBP1) captures this released enzyme at its basolateral side and shuttles it across to its luminal side. We tested whether the diabetes-induced increase of transforming growth factor-ß (TGF-ß) can influence the myocyte and EC to help transfer LPL to the vascular lumen to generate triglyceride-FA. In response to high glucose and EC heparanase secretion, this endoglycosidase is taken up by the cardiomyocyte (Wang Y, Chiu AP, Neumaier K, Wang F, Zhang D, Hussein B, Lal N, Wan A, Liu G, Vlodavsky I, Rodrigues B. Diabetes 63: 2643-2655, 2014) to stimulate matrix metalloproteinase-9 expression and the conversion of latent to active TGF-ß. In the cardiomyocyte, TGF-ß activation of RhoA enhances actin cytoskeleton rearrangement to promote LPL trafficking and secretion onto cell surface HSPG. In the EC, TGF-ß signaling promotes mesodermal homeobox 2 translocation to the nucleus, which increases the expression of GPIHBP1, which facilitates movement of LPL to the vascular lumen. Collectively, our data suggest that in the diabetic heart, TGF-ß actions on the cardiomyocyte promotes movement of LPL, whereas its action on the EC facilitates LPL shuttling. NEW & NOTEWORTHY Endothelial cells, as first responders to hyperglycemia, release heparanase, whose subsequent uptake by cardiomyocytes amplifies matrix metalloproteinase-9 expression and activation of transforming growth factor-ß. Transforming growth factor-ß increases lipoprotein lipase secretion from cardiomyocytes and promotes mesodermal homeobox 2 to enhance glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1-dependent transfer of lipoprotein lipase across endothelial cells, mechanisms that accelerate fatty acid utilization by the diabetic heart.


Assuntos
Glicemia/metabolismo , Diabetes Mellitus Experimental/enzimologia , Cardiomiopatias Diabéticas/enzimologia , Células Endoteliais/enzimologia , Metabolismo Energético , Ácidos Graxos/metabolismo , Lipase Lipoproteica/metabolismo , Miócitos Cardíacos/enzimologia , Animais , Comunicação Celular , Células Cultivadas , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/fisiopatologia , Cardiomiopatias Diabéticas/sangue , Cardiomiopatias Diabéticas/fisiopatologia , Glucuronidase/metabolismo , Proteínas de Homeodomínio/metabolismo , Masculino , Metaloproteinase 9 da Matriz/metabolismo , Proteínas Musculares/metabolismo , Ratos Wistar , Receptores de Lipoproteínas/metabolismo , Transdução de Sinais , Fator de Crescimento Transformador beta/metabolismo
8.
Am J Physiol Heart Circ Physiol ; 312(6): H1163-H1175, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28314760

RESUMO

Vascular endothelial growth factor B (VEGFB) is highly expressed in metabolically active tissues, such as the heart and skeletal muscle, suggesting a function in maintaining oxidative metabolic and contractile function in these tissues. Multiple models of heart failure have indicated a significant drop in VEGFB. However, whether there is a role for decreased VEGFB in diabetic cardiomyopathy is currently unknown. Of the VEGFB located in cardiomyocytes, there is a substantial and readily releasable pool localized on the cell surface. The immediate response to high glucose and the secretion of endothelial heparanase is the release of this surface-bound VEGFB, which triggers signaling pathways and gene expression to influence endothelial cell (autocrine action) and cardiomyocyte (paracrine effects) survival. Under conditions of hyperglycemia, when VEGFB production is impaired, a robust increase in vascular endothelial growth factor receptor (VEGFR)-1 expression ensues as a possible mechanism to enhance or maintain VEGFB signaling. However, even with an increase in VEGFR1 after diabetes, cardiomyocytes are unable to respond to VEGFB. In addition to the loss of VEGFB production and signaling, evaluation of latent heparanase, the protein responsible for VEGFB release, also showed a significant decline in expression in whole hearts from animals with chronic or acute diabetes. Defects in these numerous VEGFB pathways were associated with an increased cell death signature in our models of diabetes. Through this bidirectional interaction between endothelial cells (which secrete heparanase) and cardiomyocytes (which release VEGFB), this growth factor could provide the diabetic heart protection against cell death and may be a critical tool to delay or prevent cardiomyopathy.NEW & NOTEWORTHY We discovered a bidirectional interaction between endothelial cells (which secrete heparanase) and cardiomyocytes [which release vascular endothelial growth factor B (VEGFB)]. VEGFB promoted cell survival through ERK and cell death gene expression. Loss of VEGFB and its downstream signaling is an early event following hyperglycemia, is sustained with disease progression, and could explain diabetic cardiomyopathy.


Assuntos
Apoptose , Cardiomiopatias Diabéticas/metabolismo , Miocárdio/metabolismo , Transdução de Sinais , Fator B de Crescimento do Endotélio Vascular/metabolismo , Animais , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Comunicação Autócrina , Células Cultivadas , Diabetes Mellitus Experimental/induzido quimicamente , Cardiomiopatias Diabéticas/induzido quimicamente , Cardiomiopatias Diabéticas/genética , Cardiomiopatias Diabéticas/patologia , Células Endoteliais/enzimologia , Glucuronidase/metabolismo , Masculino , Miocárdio/patologia , Comunicação Parácrina , Ratos Wistar , Estreptozocina , Fator B de Crescimento do Endotélio Vascular/genética , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/genética , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/metabolismo
9.
Arterioscler Thromb Vasc Biol ; 36(1): 145-55, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26586663

RESUMO

OBJECTIVE: Lipoprotein lipase (LPL)-mediated triglyceride hydrolysis is the major source of fatty acid for cardiac energy. LPL, synthesized in cardiomyocytes, is translocated across endothelial cells (EC) by its transporter glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 (GPIHBP1). Previously, we have reported an augmentation in coronary LPL, which was linked to an increased expression of GPIHBP1 following moderate diabetes mellitus. We examined the potential mechanism by which hyperglycemia amplifies GPIHBP1. APPROACH AND RESULTS: Exposure of rat aortic EC to high glucose induced GPIHBP1 expression and amplified LPL shuttling across these cells. This effect coincided with an elevated secretion of heparanase. Incubation of EC with high glucose or latent heparanase resulted in secretion of vascular endothelial growth factor (VEGF). Primary cardiomyocytes, being a rich source of VEGF, when cocultured with EC, restored EC GPIHBP1 that is lost because of cell passaging. Furthermore, recombinant VEGF induced EC GPIHBP1 mRNA and protein expression within 24 hours, an effect that could be prevented by a VEGF neutralizing antibody. This VEGF-induced increase in GPIHBP1 was through Notch signaling that encompassed Delta-like ligand 4 augmentation and nuclear translocation of the Notch intracellular domain. Finally, cardiomyocytes from severely diabetic animals exhibiting attenuation of VEGF were unable to increase EC GPIHBP1 expression and had lower LPL activity at the vascular lumen in perfused hearts. CONCLUSION: EC, as the first responders to hyperglycemia, can release heparanase to liberate myocyte VEGF. This growth factor, by activating EC Notch signaling, is responsible for facilitating GPIHBP1-mediated translocation of LPL across EC and regulating LPL-derived fatty acid delivery to the cardiomyocytes.


Assuntos
Vasos Coronários/enzimologia , Diabetes Mellitus Experimental/enzimologia , Células Endoteliais/enzimologia , Lipase Lipoproteica/metabolismo , Miócitos Cardíacos/metabolismo , Comunicação Parácrina , Receptores de Lipoproteínas/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Glicemia/metabolismo , Células Cultivadas , Técnicas de Cocultura , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/genética , Metabolismo Energético , Regulação da Expressão Gênica , Glucuronidase/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Masculino , Proteínas de Membrana/metabolismo , Transporte Proteico , RNA Mensageiro/metabolismo , Ratos Wistar , Receptores de Lipoproteínas/genética , Receptores Notch/metabolismo , Transdução de Sinais , Fatores de Tempo
10.
Molecules ; 21(2): 173, 2016 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-26840288

RESUMO

In previous studies, heterocyclic amines (HCAs) have been identified as carcinogenic and a risk factor for human cancer. Therefore, the present study was designed to identify bioactive natural products capable of controlling the formation of HCAs during cooking. For this purpose we have evaluated the effect of Rosa rugosa tea extract (RTE) on the formation of HCAs in ground beef patties fried at 160 °C or 220 °C. RTE is rich in phenolic compounds and capable of inhibiting the formation of free radicals. The pyrido[3,4-b]indole (norharman) and 1-methyl-9H-pyrido[3,4-b]indole (harman) contents were significantly (p < 0.05) decreased in RTE-treated patties at 220 °C. 9H-3-Amino-1-methyl-5H-pyrido[4,3-b]indole acetate (Trp-P-2) and 3-amino-1,4-dimethyl-5H-pyrido-[4,3-b]indole acetate (Trp-P-1) were not detected at 160 °C and were statistically (p < 0.01) reduced at 220 °C compared to the control. RTE remarkably inhibited the formation of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) at 220 °C (p < 0.001) and at 160 °C (p < 0.05). 2-Amino-9H-pyrido[2,3-b]indole (AαC) and 2-amino-3-methyl-9H-pyrido[2,3-b]-indole (MeAαC) were only detected in the control group at 160 °C but were comparatively (p > 0.05) similar in the control and treated groups at 220 °C. 2-Amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), and 2-amino-3,4,8-trimethylimidazo[4,5-f]-quinoxaline (4,8-DiMeIQx) were not detected in any sample. Total HCAs were positively correlated with cooking loss. In the RTE-treated groups, 75% of the total HCAs were decreased at 160 °C and 46% at 220 °C, suggesting that RTE is effective at both temperatures and can be used during cooking at high temperatures to lessen the amount of HCAs formed.


Assuntos
Aminas/análise , Compostos Heterocíclicos/análise , Carne/análise , Fenóis/farmacologia , Rosa/química , Aminas/química , Animais , Bovinos , Culinária , Compostos Heterocíclicos/química , Temperatura Alta , Humanos , Extratos Vegetais/química , Extratos Vegetais/farmacologia
11.
Chin J Cancer ; 34(9): 394-403, 2015 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-26111932

RESUMO

INTRODUCTION: Multimodality therapy, including preoperative chemoradiotherapy (CRT) and total mesorectal excision (TME), has effectively reduced local recurrence rates of rectal cancer over the past decade. However, the benefits and risks of the addition of neoadjuvant CRT to surgery need to be evaluated. This study was to compare the efficacy of TME with versus without preoperative concurrent chemoradiotherapy (CCRT) involving XELOX regimen (oxaliplatin plus capecitabine) in Chinese patients with stages II and III mid/low rectal adenocarcinoma. METHODS: We randomly assigned patients to the TME group (TME without preoperative CCRT) or CCRT + TME group (TME with preoperative CCRT). The primary endpoint was disease-free survival (DFS); the secondary endpoints were overall survival (OS), local and distant recurrence, tumor response to CRT, toxicity, sphincter preservation, and surgical complications. An interim analysis of the potential inferiority of DFS in the CCRT + TME group was planned when the first 180 patients had been followed up for at least 6 months. RESULTS: A total of 94 patients in the TME group and 90 patients in the CCRT + TME group were able to be evaluated. The 3-year DFS and OS rates were 86.3 % and 91.5 % in the whole cohort, respectively. The 3-year DFS rates of the TME and CCRT + TME groups were 85.7% and 87.9 % (P = 0.766), respectively, and the 3-year OS rates were 90.7 % and 92.3 % (P = 0.855), respectively. The functional sphincter preservation rates of the TME and CCRT + TME groups were 71.3 % and 70.0 % (P = 0.849), respectively. In the TME group, 16 (17.0 %) patients were proven to have pTNM stage I disease after surgery. In the CCRT + TME group, 32 (35.6 %) patients achieved a pathologic complete response (pCR). CONCLUSIONS: Preliminary results indicated no significant differences in the DFS, OS, or functional sphincter preservation rates between the TME and CCRT + TME groups. However, preoperative CCRT with XELOX yielded a high pCR rate. Newer techniques are needed to improve the staging accuracy, and further investigation is warranted. CLINICAL TRIAL REGISTRATION NUMBER: Chi CTR-TRC-08000122.


Assuntos
Quimiorradioterapia , Terapia Neoadjuvante , Prognóstico , Neoplasias Retais , Adenocarcinoma , Protocolos de Quimioterapia Combinada Antineoplásica , Capecitabina , Terapia Combinada , Desoxicitidina/análogos & derivados , Intervalo Livre de Doença , Fluoruracila/análogos & derivados , Humanos , Estadiamento de Neoplasias , Compostos Organoplatínicos , Oxaliplatina , Oxaloacetatos , Estudos Prospectivos , Taxa de Sobrevida
12.
J Biol Chem ; 288(4): 2355-64, 2013 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-23184941

RESUMO

The molecular basis of the lymphatic development remains largely unknown. Using zebrafish as a model, we discovered a novel role for the Ras guanine-releasing protein 1 (RasGRP1), a protein involved in Ras activation in lymphangiogenesis. Secondary lymphatic sprouts from the posterior cardinal vein give rise to thoracic duct which is the first lymphatic vessel in zebrafish. Knockdown of rasgrp1 by injecting morpholino in zebrafish embryos impaired formation of thoracic duct accompanied by pericardial and truck edema, whereas blood vessel development of the embryos was largely unaffected. In rasgrp1-knockdown embryos, the number of sprouts producing the string of parachordal lymphangioblast cells was reduced. Meanwhile the total number of the secondary sprouts was not changed. As a result, the number of venous intersegmental vessels was increased, whereas the number of lymphatic vessel was reduced at a later stage. The lymphatic developmental defects caused by rasgrp1 knockdown could be rescued by ectopic expression of a constitutively active HRas. Further analysis revealed that RasGRP1 knockdown could synergize with flt4/vegfr3 knockdown to induce defects in lymphangiogenesis. Taken together, this finding demonstrates a critical role for RasGRP1 in lymphatic development in zebrafish.


Assuntos
Proteínas de Ligação a DNA/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Fatores de Troca do Nucleotídeo Guanina/fisiologia , Sistema Linfático/embriologia , Proteínas ras/metabolismo , Animais , Animais Geneticamente Modificados , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Perfilação da Expressão Gênica , Proteínas de Fluorescência Verde/metabolismo , Fatores de Troca do Nucleotídeo Guanina/genética , Hibridização In Situ , Linfangiogênese , Vasos Linfáticos/fisiologia , Neovascularização Fisiológica , Ducto Torácico/embriologia , Fatores de Tempo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Peixe-Zebra
13.
Am J Physiol Endocrinol Metab ; 306(11): E1274-83, 2014 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-24735886

RESUMO

In diabetes, when glucose uptake and oxidation are impaired, the heart is compelled to use fatty acid (FA) almost exclusively for ATP. The vascular content of lipoprotein lipase (LPL), the rate-limiting enzyme that determines circulating triglyceride clearance, is largely responsible for this FA delivery and increases following diabetes. Glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein [GPIHBP1; a protein expressed abundantly in the heart in endothelial cells (EC)] collects LPL from the interstitial space and transfers it across ECs onto the luminal binding sites of these cells, where the enzyme is functional. We tested whether ECs respond to hyperglycemia by increasing GPIHBP1. Streptozotocin diabetes increased cardiac LPL activity and GPIHBP1 gene and protein expression. The increased LPL and GPIHBP1 were located at the capillary lumen. In vitro, passaging EC caused a loss of GPIHBP1, which could be induced on exposure to increasing concentrations of glucose. The high-glucose-induced GPIHBP1 increased LPL shuttling across EC monolayers. GPIHBP1 expression was linked to the EC content of heparanase. Moreover, active heparanase increased GPIHBP1 gene and protein expression. Both ECs and myocyte heparan sulfate proteoglycan-bound platelet-derived growth factor (PDGF) released by heparanase caused augmentation of GPIHBP1. Overall, our data suggest that this protein "ensemble" (heparanase-PDGF-GPIHBP1) cooperates in the diabetic heart to regulate FA delivery and utilization by the cardiomyocytes. Interrupting this axis may be a novel therapeutic strategy to restore metabolic equilibrium, curb lipotoxicity, and help prevent or delay heart dysfunction that is characteristic of diabetes.


Assuntos
Células Endoteliais/metabolismo , Hiperglicemia/metabolismo , Lipase Lipoproteica/biossíntese , Receptores de Lipoproteínas/biossíntese , Animais , Transporte Biológico Ativo/fisiologia , Western Blotting , Bovinos , Técnicas de Cocultura , Citocinas/biossíntese , Diabetes Mellitus Experimental/metabolismo , Imunofluorescência , Glucose/farmacologia , Glucuronidase/metabolismo , Lipólise/fisiologia , Masculino , Monócitos/metabolismo , Miócitos Cardíacos/metabolismo , Fator de Crescimento Derivado de Plaquetas/metabolismo , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase em Tempo Real
14.
Arterioscler Thromb Vasc Biol ; 33(12): 2830-8, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24115032

RESUMO

OBJECTIVE: During diabetes mellitus, coronary lipoprotein lipase increases to promote the predominant use of fatty acids. We have reported that high glucose stimulates active heparanase secretion from endothelial cells to cleave cardiomyocyte heparan sulfate and release bound lipoprotein lipase for transfer to the vascular lumen. In the current study, we examined whether heparanase also has a function to release cardiomyocyte vascular endothelial growth factor (VEGF), and whether this growth factor influences cardiomyocyte fatty acid delivery in an autocrine manner. APPROACH AND RESULTS: Acute, reversible hyperglycemia was induced in rats, and a modified Langendorff heart perfusion was used to separate the coronary perfusate from the interstitial effluent. Coronary artery endothelial cells were exposed to high glucose to generate conditioned medium, and VEGF release from isolated cardiomyocytes was tested using endothelial cell conditioned medium or purified active and latent heparanase. Autocrine signaling of myocyte-derived VEGF on cardiac metabolism was studied. High glucose promoted latent and active heparanase secretion into endothelial cell conditioned medium, an effective stimulus for releasing cardiomyocyte VEGF. Intriguingly, latent heparanase was more efficient than active heparanase in releasing VEGF from a unique cell surface pool. VEGF augmented cardiomyocyte intracellular calcium and AMP-activated protein kinase phosphorylation and increased heparin-releasable lipoprotein lipase. CONCLUSIONS: Our data suggest that the heparanase-lipoprotein lipase-VEGF axis amplifies fatty acid delivery, a rapid and adaptive mechanism that is geared to overcome the loss of glucose consumption by the diabetic heart. If prolonged, the resultant lipotoxicity could lead to cardiovascular disease in humans.


Assuntos
Comunicação Autócrina , Vasos Coronários/enzimologia , Células Endoteliais/enzimologia , Glucuronidase/metabolismo , Hiperglicemia/enzimologia , Lipase Lipoproteica/metabolismo , Miócitos Cardíacos/enzimologia , Fator A de Crescimento do Endotélio Vascular/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Glicemia/metabolismo , Cálcio/metabolismo , Meios de Cultivo Condicionados/metabolismo , Diazóxido , Modelos Animais de Doenças , Metabolismo Energético , Ativação Enzimática , Ácidos Graxos/metabolismo , Hiperglicemia/sangue , Hiperglicemia/induzido quimicamente , Fosforilação , Ratos , Transdução de Sinais , Fatores de Tempo
15.
ACS Omega ; 9(25): 27329-27337, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38947819

RESUMO

As gas reservoir pressure decreases, edge and bottom water irregularly flow into the reservoir through storage and permeability spaces. Water influx poses a significant challenge for the development of gas reservoirs, impacting development efficiency and the ultimate recovery rate. Therefore, exploring rational optimization methods for gas well allocation is essential. This study utilizes the vertical well productivity equation considering two-phase flow and employs the net present value (NPV) to evaluate the economic benefits of gas well production. A parallel-structured genetic algorithm (GA) is developed to account for dynamic reservoir inflow, wellbore conditions, and surface facilities engineering. The new model is applied to investigate the optimal allocation of the B-21 well in the Amu Darya right bank gas reservoirs in Turkmenistan. Results indicate a match of over 90% between the cumulative gas production and water/gas ratio calculated by the proposed method and those calculated by a numerical simulation model. Compared with the traditional genetic algorithm, the new approach reduces the number of iterations to approximately 2100 (a 72.4% decrease) and significantly improves the convergence rate.

16.
Pathol Res Pract ; 259: 155369, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38820928

RESUMO

Bladder cancer is a common malignancy with a poor prognosis worldwide. Positive cofactor 4 (PC4) is widely reported to promote malignant phenotypes in various tumors. Nonetheless, the biological function and mechanism of PC4 in bladder cancer remain unclear. Here, for the first time, we report that PC4 is elevated in bladder cancer and is associated with patient survival. Moreover, PC4 deficiency obviously inhibited bladder cancer cell proliferation and metastasis by reducing the expression of genes related to cancer stemness (CD44, CD47, KLF4 and c-Myc). Through RNA-seq and experimental verification, we found that activation of the Wnt5a/ß-catenin pathway is involved in the malignant function of PC4. Mechanistically, PC4 directly interacts with Sp1 to promote Wnt5a transcription. Thus, our study furthers our understanding of the role of PC4 in cancer stemness regulation and provides a promising strategy for bladder cancer therapy.


Assuntos
Regulação Neoplásica da Expressão Gênica , Fator 4 Semelhante a Kruppel , Células-Tronco Neoplásicas , Neoplasias da Bexiga Urinária , Proteína Wnt-5a , Animais , Humanos , Camundongos , beta Catenina/metabolismo , beta Catenina/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Progressão da Doença , Fator 4 Semelhante a Kruppel/metabolismo , Células-Tronco Neoplásicas/patologia , Células-Tronco Neoplásicas/metabolismo , Fator de Transcrição Sp1/metabolismo , Fator de Transcrição Sp1/genética , Neoplasias da Bexiga Urinária/patologia , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/metabolismo , Via de Sinalização Wnt/fisiologia , Via de Sinalização Wnt/genética , Proteína Wnt-5a/metabolismo , Proteína Wnt-5a/genética
17.
Diabetes ; 73(8): 1300-1316, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38771953

RESUMO

In addition to controlling smooth muscle tone in coronary vessels, endothelial cells also influence subjacent cardiomyocyte growth. Because heparanase, with exclusive expression in endothelial cells, enables extracellular matrix remodeling, angiogenesis, metabolic reprogramming, and cell survival, it is conceivable that it could also encourage development of cardiac hypertrophy. Global heparanase overexpression resulted in physiologic cardiac hypertrophy, likely an outcome of HSPG clustering and activation of hypertrophic signaling. The heparanase autocrine effect of releasing neuregulin-1 could have also contributed to this overexpression. Hyperglycemia induced by streptozotocin-induced diabetes sensitized the heart to flow-induced release of heparanase and neuregulin-1. Despite this excess secretion, progression of diabetes caused significant gene expression changes related to mitochondrial metabolism and cell death that led to development of pathologic hypertrophy and heart dysfunction. Physiologic cardiac hypertrophy was also observed in rats with cardiomyocyte-specific vascular endothelial growth factor B overexpression. When perfused, hearts from these animals released significantly higher amounts of both heparanase and neuregulin-1. However, subjecting these animals to diabetes triggered robust transcriptome changes related to metabolism and a transition to pathologic hypertrophy. Our data suggest that in the absence of mechanisms that support cardiac energy generation and prevention of cell death, as seen after diabetes, there is a transition from physiologic to pathologic cardiac hypertrophy and a decline in cardiac function.


Assuntos
Cardiomegalia , Diabetes Mellitus Experimental , Glucuronidase , Remodelação Ventricular , Animais , Cardiomegalia/metabolismo , Cardiomegalia/patologia , Diabetes Mellitus Experimental/metabolismo , Ratos , Glucuronidase/metabolismo , Glucuronidase/genética , Remodelação Ventricular/fisiologia , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Neuregulina-1/metabolismo , Neuregulina-1/genética , Masculino
18.
Autophagy ; 20(2): 448-450, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-37876292

RESUMO

ATG5 plays a pivotal role in membrane Atg8ylation, influencing downstream processes encompassing canonical autophagy and noncanonical processes. Remarkably, genetic ablation of ATG5 in myeloid cells leads to an exacerbated pathological state in murine models of tuberculosis, characterized by an early surge in mortality much more severe when compared to the depletion of other components involved in Atg8ylation or canonical autophagy. This study shows that in the absence of ATG5, but not other core canonical autophagy factors, endolysosomal organelles display a lysosomal hypersensitivity phenotype when subjected to damage. This is in part due to a compromised recruitment of ESCRT proteins to lysosomes in need of repair. Mechanistically, in the absence of ATG5, the ESCRT protein PDCD6IP/ALIX is sequestered by the alternative conjugate ATG12-ATG3, contributing to excessive exocytic processes while not being available for lysosomal repair. Specifically, this condition increases secretion of extracellular vesicles and particles, and leads to excessive degranulation in neutrophils. Our findings uncover unique functions of ATG5 outside of the autophagy and Atg8ylation paradigm. This finding is of in vivo relevance for tuberculosis pathogenesis as modeled in mice.Abbreviations: Atg5: autophagy related 5; ESCRT: endosomal sorting complex required for transport; EVPs: extracellular vesicles and particles; FPR1: formyl peptide receptor 1; LyHYP: lysosomal hypersensitivity phenotype; LysoIP: lysosome immunopurification; Mtb: Mycobacterium tuberculosis; ORF3a: open reading frame 3a protein; PDCD6IP/ALIX: programmed cell death 6 interacting protein; SARS-CoV-2: severe acute respiratory syndrome coronavirus 2, TFEB: transcription factor EB.


Assuntos
Mycobacterium tuberculosis , Tuberculose , Animais , Camundongos , Autofagia/fisiologia , Proteína 5 Relacionada à Autofagia/metabolismo , Tuberculose/microbiologia , Complexos Endossomais de Distribuição Requeridos para Transporte/metabolismo , Lisossomos/metabolismo
19.
Clin Transl Oncol ; 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38965192

RESUMO

BACKGROUND: To develop and validate a serum protein nomogram for colorectal cancer (CRC) screening. METHODS: The serum protein characteristics were extracted from an independent sample containing 30 colorectal cancer and 12 polyp tissues along with their paired samples, and different serum protein expression profiles were validated using RNA microarrays. The prediction model was developed in a training cohort that included 1345 patients clinicopathologically confirmed CRC and 518 normal participants, and data were gathered from November 2011 to January 2017. The lasso logistic regression model was employed for features selection and serum nomogram building. An internal validation cohort containing 576 CRC patients and 222 normal participants was assessed. RESULTS: Serum signatures containing 27 secreted proteins were significantly differentially expressed in polyps and CRC compared to paired normal tissue, and REG family proteins were selected as potential predictors. The C-index of the nomogram1 (based on Lasso logistic regression model) which contains REG1A, REG3A, CEA and age was 0.913 (95% CI, 0.899 to 0.928) and was well calibrated. Addition of CA199 to the nomogram failed to show incremental prognostic value, as shown in nomogram2 (based on logistic regression model). Application of the nomogram1 in the independent validation cohort had similar discrimination (C-index, 0.912 [95% CI, 0.890 to 0.934]) and good calibration. The decision curve (DCA) and clinical impact curve (ICI) analysis demonstrated that nomogram1 was clinically useful. CONCLUSIONS: This study presents a serum nomogram that included REG1A, REG3A, CEA and age, which can be convenient for screening of colorectal cancer.

20.
bioRxiv ; 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-39026874

RESUMO

ATG5 is one of the core autophagy proteins with additional functions such as noncanonical membrane atg8ylation, which among a growing number of biological outputs includes control of tuberculosis in animal models. Here we show that ATG5 associates with retromer's core components VPS26, VPS29 and VPS35 and modulates retromer function. Knockout of ATG5 blocked trafficking of a key glucose transporter sorted by the retromer, GLUT1, to the plasma membrane. Knockouts of other genes essential for membrane atg8ylation, of which ATG5 is a component, affected GLUT1 sorting, indicating that membrane atg8ylation as a process affects retromer function and endosomal sorting. The contribution of membrane atg8ylation to retromer function in GLUT1 sorting was independent of canonical autophagy. These findings expand the scope of membrane atg8ylation to specific sorting processes in the cell dependent on the retromer and its known interactors.

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