Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 90
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Br J Cancer ; 130(6): 1046-1058, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38278978

RESUMO

BACKGROUND: The repurposing of FDA-approved drugs for anti-cancer therapies is appealing due to their established safety profiles and pharmacokinetic properties and can be quickly moved into clinical trials. Cancer progression and resistance to conventional chemotherapy remain the key hurdles in improving the clinical management of colon cancer patients and associated mortality. METHODS: High-throughput screening (HTS) was performed using an annotated library of 1,600 FDA-approved drugs to identify drugs with strong anti-CRC properties. The candidate drug exhibiting most promising inhibitory effects in in-vitro studies was tested for its efficacy using in-vivo models of CRC progression and chemoresistance and patient derived organoids (PTDOs). RESULTS: Albendazole, an anti-helminth drug, demonstrated the strongest inhibitory effects on the tumorigenic potentials of CRC cells, xenograft tumor growth and organoids from mice. Also, albendazole sensitized the chemoresistant CRC cells to 5-fluorouracil (5-FU) and oxaliplatin suggesting potential to treat chemoresistant CRC. Mechanistically, Albendazole treatment modulated the expression of RNF20, to promote apoptosis in CRC cells by delaying the G2/M phase and suppressing anti-apoptotic-Bcl2 family transcription. CONCLUSIONS: Albendazole, an FDA approved drug, carries strong therapeutic potential to treat colon cancers which are aggressive and potentially resistant to conventional chemotherapeutic agents. Our findings also lay the groundwork for further clinical testing.


Assuntos
Neoplasias do Colo , Neoplasias Colorretais , Humanos , Animais , Camundongos , Albendazol/farmacologia , Albendazol/uso terapêutico , Neoplasias Colorretais/patologia , Ubiquitina/farmacologia , Ubiquitina/uso terapêutico , Resistencia a Medicamentos Antineoplásicos , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/genética , Fluoruracila/uso terapêutico , Apoptose , Linhagem Celular Tumoral , Proliferação de Células , Ubiquitina-Proteína Ligases
2.
Am J Physiol Gastrointest Liver Physiol ; 327(2): G123-G139, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38771154

RESUMO

Microtubule-associated serine-threonine kinase-like (MASTL) has recently been identified as an oncogenic kinase given its overexpression in numerous cancers. Our group has shown that MASTL expression is upregulated in mouse models of sporadic colorectal cancer and colitis-associated cancer (CAC). CAC is one of the most severe complications of chronic inflammatory bowel disease (IBD), but a limited understanding of the mechanisms governing the switch from normal healing to neoplasia in IBD underscores the need for increased research in this area. However, MASTL levels in patients with IBD and its molecular regulation in IBD and CAC have not been studied. This study reveals that MASTL is upregulated by the cytokine interleukin (IL)-22, which promotes proliferation and has important functions in colitis recovery; however, IL-22 can also promote tumorigenesis when chronically elevated. Upon reviewing the publicly available data, we found significantly elevated MASTL and IL-22 levels in the biopsies from patients with late-stage ulcerative colitis compared with controls, and that MASTL upregulation was associated with high IL-22 expression. Our subsequent in vitro studies found that IL-22 increases MASTL expression in intestinal epithelial cell lines, which facilitates IL-22-mediated cell proliferation and downstream survival signaling. Inhibition of AKT activation abrogated IL-22-induced MASTL upregulation. We further found an increased association of carbonic anhydrase IX (CAIX) with MASTL in IL-22-treated cells, which stabilized MASTL expression. Inhibition of CAIX prevented IL-22-induced MASTL expression and cell survival. Overall, we show that IL-22/AKT signaling increases MASTL expression to promote cell survival and proliferation. Furthermore, CAIX associates with and stabilizes MASTL in response to IL-22 stimulation.NEW & NOTEWORTHY MASTL is upregulated in colorectal cancer; however, its role in colitis and colitis-associated cancer is poorly understood. This study is the first to draw a link between MASTL and IL-22, a proinflammatory/intestinal epithelial recovery-promoting cytokine that is also implicated in colon tumorigenesis. We propose that IL-22 increases MASTL protein stability by promoting its association with CAIX potentially via AKT signaling to promote cell survival and proliferation.


Assuntos
Interleucina 22 , Interleucinas , Mucosa Intestinal , Interleucinas/metabolismo , Humanos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/patologia , Células Epiteliais/metabolismo , Células Epiteliais/efeitos dos fármacos , Animais , Proliferação de Células , Transdução de Sinais , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/genética , Colite Ulcerativa/metabolismo , Colite Ulcerativa/patologia , Camundongos , Regulação para Cima , Proteínas Proto-Oncogênicas c-akt/metabolismo , Anidrase Carbônica IX/metabolismo , Anidrase Carbônica IX/genética , Antígenos de Neoplasias
3.
Am J Physiol Gastrointest Liver Physiol ; 327(5): G685-G696, 2024 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-39224072

RESUMO

Congenital heart disease (CHD) is the most common birth defect, occurring in roughly 40,000 U.S. births annually. Malnutrition and feeding intolerance (FI) in CHD range from 30% to 42% and are associated with longer hospitalization and increased mortality. Cardiopulmonary bypass (CPB) required for surgical repair of CHD induces a systemic inflammatory response worsening intestinal dysbiosis and leading to intestinal epithelial barrier dysfunction (EBD), possibly contributing to postoperative FI. The objective of this study was to determine the relationship of postoperative FI with intestinal microbiome, short-chain fatty acids (SCFAs), and EBD in pediatric CHD after cardiac surgery. This was a prospective study of patients aged 0-15 years undergoing cardiac surgery with CPB. Samples were collected preoperatively and postoperatively to evaluate the gut microbiome, plasma EBD markers, short-chain fatty acids (SCFAs), and plasma cytokines. Clinical data were collected to calculate a FI score and evaluate patient status postoperatively. We enrolled 26 CPB patients and identified FI (n = 13). Patients with FI had unique microbial shifts with the reduced SCFA-producing organisms Rothia, Clostridium innocuum, and Intestinimonas. Patients who developed FI had associated elevations in the plasma EBD markers claudin-2 (P < 0.05), claudin-3 (P < 0.01), and fatty acid binding protein (P < 0.01). Patients with FI had reduced plasma and stool SCFAs. Mediation analysis showed the microbiome functional shift was associated with reductions in stool butyric and propionic acid in patients with FI. In conclusion, we provide novel evidence that intestinal dysbiosis, markers of EBD, and SCFA depletion are associated with FI. These data will help identify mechanisms and therapeutics to improve clinical outcomes following pediatric cardiac surgery.NEW & NOTEWORTHY Feeding intolerance contributes to postoperative morbidity following pediatric cardiac surgery. The intestinal microbiome and milieu play a vital role in gut function. Short-chain fatty acids are gut and cardioprotective metabolites produced by commensal bacteria and help maintain appropriate barrier function. Depletion of these metabolites and barrier dysfunction contribute to postoperative feeding intolerance following cardiac surgery. Identifying mechanistic targets to improve the intestinal milieu with the goal of improved nutrition and clinical outcomes is critical.


Assuntos
Disbiose , Ácidos Graxos Voláteis , Microbioma Gastrointestinal , Cardiopatias Congênitas , Humanos , Lactente , Masculino , Feminino , Pré-Escolar , Ácidos Graxos Voláteis/metabolismo , Criança , Cardiopatias Congênitas/cirurgia , Estudos Prospectivos , Adolescente , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Intolerância Alimentar , Recém-Nascido , Mucosa Intestinal/metabolismo , Complicações Pós-Operatórias , Ponte Cardiopulmonar/efeitos adversos
4.
Pharm Res ; 40(1): 107-122, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36271204

RESUMO

Nucleic acid (NA) therapy has gained importance over the past decade due to its high degree of selectivity and minimal toxic effects over conventional drugs. Currently, intravenous (IV) or intramuscular (IM) formulations constitute majority of the marketed formulations containing nucleic acids. However, oral administration is traditionally preferred due to ease of administration as well as higher patient compliance. To leverage the benefits of oral delivery for NA therapy, the NA of interest must be delivered to the target site avoiding all degrading and inhibiting factors during its transition through the gastrointestinal tract. The oral route presents myriad of challenges to NA delivery, making formulation development challenging. Researchers in the last few decades have formulated various delivery systems to overcome such challenges and several reviews summarize and discuss these strategies in detail. However, there is a need to differentiate between the approaches based on target so that in future, delivery strategies can be developed according to the goal of the study and for efficient delivery to the desired site. The goal of this review is to summarize the mechanisms for target specific delivery, list and discuss the formulation strategies used for oral delivery of NA therapies and delineate the similarities and differences between local and systemic targeting oral delivery systems and current challenges.


Assuntos
Sistemas de Liberação de Medicamentos , Ácidos Nucleicos , Humanos , Administração Oral , Trato Gastrointestinal
5.
Int J Mol Sci ; 22(9)2021 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-33946266

RESUMO

Despite significant improvements in clinical management, pancreatic cancer (PC) remains one of the deadliest cancer types, as it is prone to late detection with extreme metastatic properties. The recent findings that pancreatic cancer stem cells (PaCSCs) contribute to the tumorigenesis, progression, and chemoresistance have offered significant insight into the cancer malignancy and development of precise therapies. However, the heterogeneity of cancer and signaling pathways that regulate PC have posed limitations in the effective targeting of the PaCSCs. In this regard, the role for K-RAS, TP53, Transforming Growth Factor-ß, hedgehog, Wnt and Notch and other signaling pathways in PC progression is well documented. In this review, we discuss the role of PaCSCs, the underlying molecular and signaling pathways that help promote pancreatic cancer development and metastasis with a specific focus on the regulation of PaCSCs. We also discuss the therapeutic approaches that target different PaCSCs, intricate mechanisms, and therapeutic opportunities to eliminate heterogeneous PaCSCs populations in pancreatic cancer.


Assuntos
Antineoplásicos/farmacologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Neoplasias Pancreáticas/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Animais , Antineoplásicos/uso terapêutico , Carcinogênese/efeitos dos fármacos , Carcinogênese/metabolismo , Carcinogênese/patologia , Descoberta de Drogas , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Proteínas Hedgehog/metabolismo , Humanos , Terapia de Alvo Molecular , Invasividade Neoplásica/patologia , Invasividade Neoplásica/prevenção & controle , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Receptores Notch/metabolismo , Via de Sinalização Wnt/efeitos dos fármacos
6.
Respir Res ; 21(1): 97, 2020 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-32321514

RESUMO

BACKGROUND: Environmental organic dust exposures enriched in Toll-like receptor (TLR) agonists can reduce allergic asthma development but are associated with occupational asthma and chronic bronchitis. The TLR adaptor protein myeloid differentiation factor88 (MyD88) is fundamental in regulating acute inflammatory responses to organic dust extract (ODE), yet its role in repetitive exposures is unknown and could inform future strategies. METHODS: Wild-type (WT) and MyD88 knockout (KO) mice were exposed intranasally to ODE or saline daily for 3 weeks (repetitive exposure). Repetitively exposed animals were also subsequently rested with no treatments for 4 weeks followed by single rechallenge with saline/ODE. RESULTS: Repetitive ODE exposure induced neutrophil influx and release of pro-inflammatory cytokines and chemokines were profoundly reduced in MyD88 KO mice. In comparison, ODE-induced cellular aggregates, B cells, mast cell infiltrates and serum IgE levels remained elevated in KO mice and mucous cell metaplasia was increased. Expression of ODE-induced tight junction protein(s) was also MyD88-dependent. Following recovery and then rechallenge with ODE, inflammatory mediators, but not neutrophil influx, was reduced in WT mice pretreated with ODE coincident with increased expression of IL-33 and IL-10, suggesting an adaptation response. Repetitively exposed MyD88 KO mice lacked inflammatory responsiveness upon ODE rechallenge. CONCLUSIONS: MyD88 is essential in mediating the classic airway inflammatory response to repetitive ODE, but targeting MyD88 does not reduce mucous cell metaplasia, lymphocyte influx, or IgE responsiveness. TLR-enriched dust exposures induce a prolonged adaptation response that is largely MyD88-independent. These findings demonstrate the complex role of MyD88-dependent signaling during acute vs. chronic organic dust exposures.


Assuntos
Adaptação Fisiológica/fisiologia , Poeira , Exposição Ambiental/efeitos adversos , Exposição por Inalação/efeitos adversos , Pneumopatias/metabolismo , Fator 88 de Diferenciação Mieloide/metabolismo , Animais , Feminino , Pneumopatias/induzido quimicamente , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
7.
Am J Physiol Endocrinol Metab ; 316(5): E880-E894, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30721098

RESUMO

Long-chain acyl-CoA synthetase 4 (ACSL4) has a unique substrate specificity for arachidonic acid. Hepatic ACSL4 is coregulated with the phospholipid (PL)-remodeling enzyme lysophosphatidylcholine (LPC) acyltransferase 3 by peroxisome proliferator-activated receptor δ to modulate the plasma triglyceride (TG) metabolism. In this study, we investigated the acute effects of hepatic ACSL4 deficiency on lipid metabolism in adult mice fed a high-fat diet (HFD). Adenovirus-mediated expression of a mouse ACSL4 shRNA (Ad-shAcsl4) in the liver of HFD-fed mice led to a 43% reduction of hepatic arachidonoyl-CoA synthetase activity and a 53% decrease in ACSL4 protein levels compared with mice receiving control adenovirus (Ad-shLacZ). Attenuated ACSL4 expression resulted in a substantial decrease in circulating VLDL-TG levels without affecting plasma cholesterol. Lipidomics profiling revealed that knocking down ACSL4 altered liver PL compositions, with the greatest impact on accumulation of abundant LPC species (LPC 16:0 and LPC 18:0) and lysophosphatidylethanolamine (LPE) species (LPE 16:0 and LPE 18:0). In addition, fasting glucose and insulin levels were higher in Ad-shAcsl4-transduced mice versus control (Ad-shLacZ). Glucose tolerance testing further indicated an insulin-resistant phenotype upon knockdown of ACSL4. These results provide the first in vivo evidence that ACSL4 plays a role in plasma TG and glucose metabolism and hepatic PL synthesis of hyperlipidemic mice.


Assuntos
Glicemia/metabolismo , Coenzima A Ligases/genética , Resistência à Insulina/genética , Lipoproteínas VLDL/metabolismo , Fígado/metabolismo , Fosfolipídeos/biossíntese , Triglicerídeos/metabolismo , Animais , HDL-Colesterol/metabolismo , LDL-Colesterol/metabolismo , VLDL-Colesterol/metabolismo , Dieta Hiperlipídica , Perfilação da Expressão Gênica , Técnicas de Silenciamento de Genes , Teste de Tolerância a Glucose , Insulina/metabolismo , Metabolismo dos Lipídeos/genética , Lipidômica , Lisofosfolipídeos/metabolismo , Camundongos , Proteína Supressora de Tumor p53/metabolismo
8.
Int J Mol Sci ; 21(1)2019 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-31861759

RESUMO

Claudins are cell-cell adhesion proteins, which are expressed in tight junctions (TJs), the most common apical cell-cell adhesion. Claudin proteins help to regulate defense and barrier functions, as well as differentiation and polarity in epithelial and endothelial cells. A series of studies have now reported dysregulation of claudin proteins in cancers. However, the precise mechanisms are still not well understood. Nonetheless, studies have clearly demonstrated a causal role of multiple claudins in the regulation of epithelial to mesenchymal transition (EMT), a key feature in the acquisition of a cancer stem cell phenotype in cancer cells. In addition, claudin proteins are known to modulate therapy resistance in cancer cells, a feature associated with cancer stem cells. In this review, we have focused primarily on highlighting the causal link between claudins, cancer stem cells, and therapy resistance. We have also contemplated the significance of claudins as novel targets in improving the efficacy of cancer therapy. Overall, this review provides a much-needed understanding of the emerging role of claudin proteins in cancer malignancy and therapeutic management.


Assuntos
Claudinas/metabolismo , Neoplasias/metabolismo , Células-Tronco Neoplásicas/metabolismo , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Claudinas/análise , Resistencia a Medicamentos Antineoplásicos , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Humanos , Neoplasias/diagnóstico , Neoplasias/tratamento farmacológico , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/patologia , Prognóstico
9.
Mol Cancer ; 17(1): 111, 2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-30068336

RESUMO

BACKGROUND: Chemotherapeutic agents that modulate cell cycle checkpoints and/or tumor-specific pathways have shown immense promise in preclinical and clinical studies aimed at anti-cancer therapy. MASTL (Greatwall in Xenopus and Drosophila), a serine/threonine kinase controls the final G2/M checkpoint and prevents premature entry of cells into mitosis. Recent studies suggest that MASTL expression is highly upregulated in cancer and confers resistance against chemotherapy. However, the role and mechanism/s of MASTL mediated regulation of tumorigenesis remains poorly understood. METHODS: We utilized a large patient cohort and mouse models of colon cancer as well as colon cancer cells to determine the role of Mastl and associated mechanism in colon cancer. RESULTS: Here, we show that MASTL expression increases in colon cancer across all cancer stages compared with normal colon tissue (P < 0.001). Also, increased levels of MASTL associated with high-risk of the disease and poor prognosis. Further, the shRNA silencing of MASTL expression in colon cancer cells induced cell cycle arrest and apoptosis in vitro and inhibited xenograft-tumor growth in vivo. Mechanistic analysis revealed that MASTL expression facilitates colon cancer progression by promoting the ß-catenin/Wnt signaling, the key signaling pathway implicated in colon carcinogenesis, and up-regulating anti-apoptotic proteins, Bcl-xL and Survivin. Further studies where colorectal cancer (CRC) cells were subjected to 5-fluorouracil (5FU) treatment revealed a sharp increase in MASTL expression upon chemotherapy, along with increases in Bcl-xL and Survivin expression. Most notably, inhibition of MASTL in these cells induced chemosensitivity to 5FU with downregulation of Survivin and Bcl-xL expression. CONCLUSION: Overall, our data shed light on the heretofore-undescribed mechanistic role of MASTL in key oncogenic signaling pathway/s to regulate colon cancer progression and chemo-resistance that would tremendously help to overcome drug resistance in colon cancer treatment.


Assuntos
Neoplasias do Colo/patologia , Resistencia a Medicamentos Antineoplásicos , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Regulação para Cima , Células CACO-2 , Neoplasias do Colo/genética , Neoplasias do Colo/metabolismo , Progressão da Doença , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Células HCT116 , Células HT29 , Humanos , Estadiamento de Neoplasias , Transplante de Neoplasias , Prognóstico , Análise de Sobrevida , Via de Sinalização Wnt
10.
Semin Cell Dev Biol ; 42: 58-65, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26025580

RESUMO

The role of the tight junctions (TJ) in controlling paracellular traffic of ions and molecules, through the regulation of claudin proteins, is now established. However, it has also become increasingly evident that claudin proteins, as integral components of the TJs, play crucial role in maintaining the cell-cell integrity. In conformity, deregulation of claudin expression and cellular distribution in cancer tissues has been widely documented and correlated with cancer progression and metastasis. However, this correlation is not unidirectional and rather suggests tissue specific regulations. Irrespective, if the widely described correlations between altered claudin expression and cancer initiation/progression could be established, they may serve as important markers for prognostic purposes and potential therapeutic targets. In this review, we summarize data from screening of the cancer tissues, manipulation of claudin expression in cells and animals subjected to cancer models, and how claudins are regulated in cancer. The focus of this article remains analysis of the association between cancer and the claudins and to decipher clinical relevance.


Assuntos
Claudinas/metabolismo , Neoplasias/patologia , Animais , Claudinas/genética , Metilação de DNA , Epigênese Genética , Transição Epitelial-Mesenquimal , Regulação da Expressão Gênica , Humanos
11.
Pflugers Arch ; 469(1): 69-75, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27988840

RESUMO

Environment affects an individual's development and disease risk which then suggest that the environmental cues must have ways of reaching to the cellular nuclei to orchestrate desired genetic changes. Polarized and differentiated epithelial cells join together by cell-cell adhesions to create a protective sheet which separates body's internal milieu from its environment, albeit in highly regulated manner. Among these cell-cell adhesions, a key role of tight junction, the apical cell-cell adhesion, in maintaining epithelial cell polarity and differentiation is well recognized. Moreover, significant changes in expression and cellular distribution of claudin proteins, integral component of the tight junction, characterize pathophysiological changes including neoplastic growth and progression. Studies have further confirmed existence of complex claudin-based interactomes and demonstrated that changes in such protein partnering can influence barrier integrity and communication between a cell and its environment to produce undesired outcome. Cell signaling is the process by which cells respond to their environment to make dynamic decisions to live, grow and proliferate, or die. Thus, pivotal role of the deregulated tight junction structure/function in influencing cellular signaling cascades to alter cellular phenotype can be envisaged, however, is not well understood. Needless to mention that advanced knowledge in this area can help improve therapeutic considerations and preventive measures. Here, we discuss potential role of the tight junction in the regulation of "outside-in" signaling to regulate cancer growth, with specific focus upon the claudin family of proteins.


Assuntos
Carcinogênese/metabolismo , Claudinas/metabolismo , Transdução de Sinais/fisiologia , Animais , Células Epiteliais/metabolismo , Humanos , Junções Íntimas/metabolismo
12.
Exp Cell Res ; 349(1): 119-127, 2016 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-27742576

RESUMO

Epithelial-mesenchymal transition (EMT) is an important mechanism in cancer progression and malignancy including colorectal cancer (CRC). Importantly, inflammatory mediators are critical constituents of the local tumor environment and an intimate link between CRC progression and inflammation is now validated. We and others have reported key role of the deregulated claudin-1 expression in colon carcinogenesis including colitis-associated colon cancer (CAC). However, the causal association between claudin-1 expression and inflammation-induced colon cancer progression remains unclear. Here we demonstrate, TNF-α, a pro-inflammatory cytokine, regulates claudin-1 to modulate epithelial to mesenchymal transition (EMT) and migration in colon adenocarcinoma cells. Importantly, colon cancer cells cultured in the presence of TNF-α (10ng/ml), demonstrated a sharp decrease in E-cadherin expression and an increase in vimentin expression (versus control cells). Interestingly, TNF-α treatment also upregulated (and delocalized) claudin-1 expression in a time-dependent manner accompanied by increase in proliferation and wound healing. Furthermore, similar to our previous observation that claudin-1 overexpression in CRC cells induces ERK1/2 and Src- activation, signaling associated with colon cancer cell survival and transformation, TNF-α-treatment induced upregulation of phospho-ERK1/2 and -Src expression. The shRNA-mediated inhibition of claudin-1 expression largely abrogated the TNF-α-induced changes in EMT, proliferation, migration, p-Erk and p-Src expression. Taken together, our data demonstrate TNF-α mediated regulation of claudin-1 and tumorigenic abilities of colon cancer cells and highlights a key role of deregulated claudin-1 expression in inflammation-induced colorectal cancer growth and progression, through the regulation of the ERK and Src-signaling.


Assuntos
Adenocarcinoma/patologia , Movimento Celular/efeitos dos fármacos , Claudina-1/metabolismo , Neoplasias Colorretais/patologia , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Fator de Necrose Tumoral alfa/farmacologia , Adenocarcinoma/metabolismo , Biomarcadores Tumorais/metabolismo , Permeabilidade da Membrana Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Neoplasias Colorretais/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Técnicas de Silenciamento de Genes , Células HT29 , Humanos , Fosforilação/efeitos dos fármacos , Quinases da Família src/metabolismo
13.
J Biol Chem ; 289(12): 8532-44, 2014 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-24509849

RESUMO

Epithelial cells lining the gastrointestinal tract and kidney have different abilities to facilitate paracellular and transcellular transport of water and solutes. In the kidney, the proximal tubule allows both transcellular and paracellular transport, while the collecting duct primarily facilitates transcellular transport. The claudins and E-cadherin are major structural and functional components regulating paracellular transport. In this study we present the novel finding that the transmembrane matrix receptors, integrins, play a role in regulating paracellular transport of renal proximal tubule cells. Deleting the integrin ß1 subunit in these cells converts them from a "loose" epithelium, characterized by low expression of E-cadherin and claudin-7 and high expression of claudin-2, to a "tight" epithelium with increased E-cadherin and claudin-7 expression and decreased claudin-2 expression. This effect is mediated by the integrin ß1 cytoplasmic tail and does not entail ß1 heterodimerization with an α-subunit or its localization to the cell surface. In addition, we demonstrate that deleting the ß1 subunit in the proximal tubule of the kidney results in a major urine-concentrating defect. Thus, the integrin ß1 tail plays a key role in regulating the composition and function of tight and adherens junctions that define paracellular transport properties of terminally differentiated renal proximal tubule epithelial cells.


Assuntos
Deleção de Genes , Integrina beta1/genética , Integrina beta1/metabolismo , Túbulos Renais Proximais/citologia , Túbulos Renais Proximais/metabolismo , Animais , Caderinas/genética , Caderinas/metabolismo , Permeabilidade da Membrana Celular , Células Cultivadas , Claudina-2/genética , Claudina-2/metabolismo , Regulação para Baixo , Células Epiteliais/metabolismo , Integrina beta1/análise , Camundongos , Permeabilidade , Regulação para Cima , Urina/química
14.
J Immunol ; 190(4): 1849-58, 2013 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-23303670

RESUMO

Patients suffering from ulcerative colitis (UC) exhibit chronic colonic inflammation caused by a dysregulated mucosal immune response and epithelial barrier disruption. Th2 cytokines, including IL-13, have been implicated in the pathogenesis of UC. IL-13 induces phosphorylation of STAT6, and we previously demonstrated increased epithelial p-STAT6 in children with UC. In this study, we investigated the role of STAT6 in oxazolone colitis, a murine model of UC, by inducing colitis in STAT6-deficient (STAT6(-/-)) and wild type (WT) mice. We observed increased epithelial cell, T cell, macrophage, and NKT cell STAT6 phosphorylation, as well as increased p-STAT6(+) IL-13-producing NKT cells, in colitic WT mice. Colitis was attenuated in STAT6(-/-) mice, with improvements in weight, colon length, and histopathology. There was decreased induction of the pore-forming tight junction protein claudin-2 in STAT6(-/-) mice. Similarly, short hairpin RNA STAT6 knockdown reduced claudin-2 induction and transepithelial resistance decrease in IL-13-treated human T84 cells. Tissue expression of IL-13, IFN-γ, IL-17, and IL-10 mRNA was similarly induced in WT and STAT6(-/-) colitic mice; however, we observed increased mRNA expression for the Th2-inducing cytokines IL-33 and thymic stromal lymphopoietin in WT mice with colitis, which was abrogated in STAT6(-/-) mice. Mesenteric lymph node cells from STAT6(-/-) mice with colitis exhibited reduced secretion of IL-4, IL-5, IL-13, and IFN-γ. IL-33 augmented mesenteric lymph node cell secretion of IL-5, IL-13, IL-6, and IFN-γ. These data implicate STAT6 in the pathogenesis of colitis in vivo with important roles in altering epithelial barrier function and regulating Th2-inducing cytokine production.


Assuntos
Claudina-2/antagonistas & inibidores , Colite Ulcerativa/imunologia , Citocinas/antagonistas & inibidores , Regulação para Baixo/imunologia , Oxazolona/administração & dosagem , Fator de Transcrição STAT6/deficiência , Índice de Gravidade de Doença , Células Th2/imunologia , Adjuvantes Imunológicos/administração & dosagem , Adjuvantes Imunológicos/efeitos adversos , Adjuvantes Imunológicos/antagonistas & inibidores , Animais , Linhagem Celular , Claudina-2/biossíntese , Claudina-2/genética , Colite Ulcerativa/induzido quimicamente , Colite Ulcerativa/prevenção & controle , Citocinas/biossíntese , Citocinas/genética , Modelos Animais de Doenças , Regulação para Baixo/genética , Regulação da Expressão Gênica/imunologia , Haptenos/administração & dosagem , Haptenos/efeitos adversos , Humanos , Mucosa Intestinal/imunologia , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Masculino , Camundongos , Camundongos Knockout , Células T Matadoras Naturais/imunologia , Células T Matadoras Naturais/metabolismo , Células T Matadoras Naturais/patologia , Oxazolona/efeitos adversos , Oxazolona/antagonistas & inibidores , Fator de Transcrição STAT6/genética , Células Th2/metabolismo , Células Th2/patologia
15.
Int J Phytoremediation ; 17(7): 709-15, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25976885

RESUMO

The present study was conducted to evaluate the ability of a high biomass producing, drought tolerant succulent plant Mauritius hemp (Furcraea gigantea Vent.) for its tolerance to different levels of Cr (0, 25, 50, 100 and 200 mg Cr kg soil(-1)) and its potential for phytoremediation purposes. Based on the data on inhibition of the growth of plants with Cr, tolerance index and grade of growth inhibition, it was observed that the plant could tolerate up to 50 mg Cr kg (-1) soil. Absorption of Cr from soil to plant and its translocation into plant tissues were discussed in terms of bio concentration factor (BCF), transfer factor (TF), and translocation efficiency (TE%). Cr was mainly accumulated in the roots and exclusion of Cr was found to be the principal physiological tolerance mechanism followed by a marked increase in proline, ascorbic acid, total free amino acids in the leaf tissue and malic acid in the rhizosphere samples to counter Cr stress. Based on the tissue concentration of Cr (< 300 µg g(-1) in the leaves and TF<1), it was concluded that, Furcraea gigantea could not be considered a hyperaccumulator and therefore unsuitable for phytoextraction of Cr. Nevertheless, Furcraea gigantea could be a suitable candidate for phytostablization of Cr contaminated soils.


Assuntos
Cromo/metabolismo , Liliaceae/metabolismo , Poluentes do Solo/metabolismo , Biodegradação Ambiental , Relação Dose-Resposta a Droga
16.
Gut ; 63(4): 622-34, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23766441

RESUMO

OBJECTIVE: Claudin-1 expression is increased and dysregulated in colorectal cancer and causally associates with the dedifferentiation of colonic epithelial cells, cancer progression and metastasis. Here, we have sought to determine the role claudin-1 plays in the regulation of intestinal epithelial homeostasis. DESIGN: We have used a novel villin-claudin-1 transgenic (Cl-1Tg) mouse as model (with intestinal claudin-1 overexpression). The effect of claudin-1 expression upon colonic epithelial differentiation, lineage commitment and Notch-signalling was determined using immunohistochemical, immunoblot and real-time PCR analysis. The frequently used mouse model of dextran sodium sulfate (DSS)-colitis was used to model inflammation, injury and repair. RESULTS: In Cl-1Tg mice, normal colonocyte differentiation programme was disrupted and goblet cell number and mucin-2 (muc-2) expressions were significantly downregulated while Notch- and ERK1/2-signalling were upregulated, compared with the wild type-littermates. Cl-1Tg mice were also susceptible to colonic inflammation and demonstrated impaired recovery and hyperproliferation following the DSS-colitis. Our data further show that claudin-1 regulates Notch-signalling through the regulation of matrix metalloproteinase-9 (MMP-9) and p-ERK signalling to regulate proliferation and differentiation. CONCLUSIONS: Claudin-1 helps regulate intestinal epithelial homeostasis through the regulation of Notch-signalling. An upregulated claudin-1 expression induces MMP-9 and p-ERK signalling to activate Notch-signalling, which in turn inhibits the goblet cell differentiation. Decreased goblet cell number decreases muc-2 expression and thus enhances susceptibility to mucosal inflammation. Claudin-1 expression also induces colonic epithelial proliferation in a Notch-dependent manner. Our findings may help understand the role of claudin-1 in the regulation of inflammatory bowel diseases and CRC.


Assuntos
Claudina-1/fisiologia , Colo/fisiologia , Receptores Notch/fisiologia , Transdução de Sinais/fisiologia , Animais , Apoptose/fisiologia , Diferenciação Celular/fisiologia , Proliferação de Células , Colite/induzido quimicamente , Colite/fisiopatologia , Sulfato de Dextrana/farmacologia , Modelos Animais de Doenças , Homeostase/fisiologia , Mucosa Intestinal/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Reação em Cadeia da Polimerase em Tempo Real
17.
Mol Cancer ; 13: 167, 2014 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-24997475

RESUMO

BACKGROUND: The tight junction protein Claudin-1, a claudin family member, has been implicated in several gastro-intestinal pathologies including inflammatory bowel disease (IBD) and colorectal cancer (CRC). In this regard, we have demonstrated that claudin-1 expression in colon cancer cells potentiates their tumorigenic ability while in vivo expression of claudin-1 in the intestinal epithelial cells (IECs) promotes Notch-activation, inhibits goblet cell differentiation and renders susceptibility to mucosal inflammation. Notably, a key role of inflammation in colon cancer progression is being appreciated. Therefore, we examined whether inflammation plays an important role in claudin-1-dependent upregulation of colon carcinogenesis. METHODS: APCmin mice were crossed with Villin-claudin-1 transgenic mice to generate APC-Cldn1 mice. H&E stained colon tissues were assessed for tumor number, size and histological grade. Additionally, microarray and qPCR analyses of colonic tumors were performed to assess molecular changes due to claudin-1 expression. APC-Cldn1 and APCmin controls were assessed for colonic permeability via rectal administration of FITC-dextran, and bacterial translocation via qPCR analysis of 16S rDNA. RESULTS: Claudin-1 overexpression in APCmin mice significantly increased (~4-fold) colonic tumor growth and size, and decreased survival. Furthermore, transcriptome analysis supported upregulated proliferation, and increased Wnt and Notch-signaling in APC-Cldn1 mice. APC-Cldn1 mice also demonstrated inhibition of mucosal defense genes while expression of pro-inflammatory genes was sharply upregulated, especially the IL-23/IL-17 signaling. We predict that increased Notch/Wnt-signaling underlie the early onset of adenoma formation in APC-Cldn1 mice. An increase in mucosal permeability due to the adenomas and the inherent barrier defect in these mice further facilitate bacterial translocation into the mucosa to induce inflammation, which in turn promote the tumorigenesis. CONCLUSION: Taken together, these results confirm the role of claudin-1 as a promoter of colon tumorigenesis and further identify the role of the dysregulated antigen-tumor interaction and inflammation in claudin-1-dependent upregulation of colon tumorigenesis.


Assuntos
Proteína da Polipose Adenomatosa do Colo/genética , Polipose Adenomatosa do Colo/genética , Transformação Celular Neoplásica/genética , Claudina-1/biossíntese , Neoplasias do Colo/genética , Polipose Adenomatosa do Colo/patologia , Animais , Claudina-1/genética , Neoplasias do Colo/patologia , Células Epiteliais/metabolismo , Regulação Neoplásica da Expressão Gênica , Subunidade p19 da Interleucina-23/biossíntese , Mucosa Intestinal/metabolismo , Intestinos/microbiologia , Intestinos/patologia , Camundongos , Mucina-2/biossíntese
18.
Cells ; 13(11)2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38891089

RESUMO

Inflammatory bowel disease (IBD) is a chronic gut disorder that also elevates the risk of colorectal cancer (CRC). The global incidence and severity of IBD are rising, yet existing therapies often lead to severe side effects. Curcumin offers potent anti-inflammatory and chemotherapeutic properties. However, its clinical translation is hindered by rapid metabolism, as well as poor water solubility and stability, which limits its bioavailability. To address these challenges, we developed OC-S, a water-soluble and colon-targeted curcumin formulation that protects against colitis in mice. The current study advances OC-S as a dietary supplement by establishing its stability and compatibility with various commercial dietary products. Further, OC-S exhibited specific binding to inflamed colon tissue, potentially aiding in targeted drug retention at the inflammation site in colitis with diarrhea symptoms. We further investigated its efficacy in vivo and in vitro using a murine model of colitis and tumoroids from APCmin mice. OC-S significantly reduced colitis severity and pro-inflammatory cytokine expression compared with curcumin, even at very low doses (5 mg/kg/day). It also demonstrated higher anti-proliferative activity in CRC cells and colon cancer tumoroids vs. curcumin. Overall, this study demonstrated that OC-S effectively targets and retains water-soluble curcumin at the inflamed colon sites, while showing promise in addressing both colitis and colorectal cancer, which potentially paves the way for OC-S to advance into clinical development as a dietary product for both IBD and CRC.


Assuntos
Colite , Neoplasias Colorretais , Curcumina , Animais , Curcumina/farmacologia , Curcumina/uso terapêutico , Neoplasias Colorretais/patologia , Neoplasias Colorretais/tratamento farmacológico , Colite/tratamento farmacológico , Colite/patologia , Colite/induzido quimicamente , Camundongos , Humanos , Camundongos Endogâmicos C57BL , Modelos Animais de Doenças , Proliferação de Células/efeitos dos fármacos , Suplementos Nutricionais , Masculino , Substâncias Protetoras/farmacologia
19.
J Mol Cell Cardiol ; 57: 106-18, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23395853

RESUMO

Diabetic cardiomyopathy (DCM) is a significant contributor to the morbidity and mortality associated with diabetes and metabolic syndrome. Retinoids, through activation of retinoic acid receptor (RAR) and retinoid x receptor (RXR), have been linked to control glucose and lipid homeostasis, with effects on obesity and diabetes. However, the functional role of RAR and RXR in the development of DCM remains unclear. Zucker diabetic fatty (ZDF) and lean rats were treated with Am580 (RARα agonist) or LGD1069 (RXR agonist) for 16 weeks, and cardiac function and metabolic alterations were determined. Hyperglycemia, hyperlipidemia and insulin resistance were observed in ZDF rats. Diabetic cardiomyopathy was characterized in ZDF rats by increased oxidative stress, apoptosis, fibrosis, inflammation, activation of MAP kinases and NF-κB signaling and diminished Akt phosphorylation, along with decreased glucose transport and increased cardiac lipid accumulation, and ultimately diastolic dysfunction. Am580 and LGD1069 attenuated diabetes-induced cardiac dysfunction and the pathological alterations, by improving glucose tolerance and insulin resistance; facilitating Akt activation and glucose utilization, and attenuating oxidative stress and interrelated MAP kinase and NF-κB signaling pathways. Am580 inhibited body weight gain, attenuated the increased cardiac fatty acid uptake, ß-oxidation and lipid accumulation in the hearts of ZDF rats. However, LGD1069 promoted body weight gain, hyperlipidemia and cardiac lipid accumulation. In conclusion, our data suggest that activation of RAR and RXR may have therapeutic potential in the treatment of diabetic cardiomyopathy. However, further studies are necessary to clarify the role of RAR and RXR in the regulation of lipid metabolism and homeostasis.


Assuntos
Benzoatos/farmacologia , Diabetes Mellitus Tipo 2/metabolismo , Cardiomiopatias Diabéticas/fisiopatologia , Receptores do Ácido Retinoico/agonistas , Receptores X de Retinoides/agonistas , Tetra-Hidronaftalenos/farmacologia , Animais , Benzoatos/uso terapêutico , Bexaroteno , Glicemia , Colágeno/genética , Colágeno/metabolismo , Diabetes Mellitus Tipo 2/complicações , Cardiomiopatias Diabéticas/tratamento farmacológico , Cardiomiopatias Diabéticas/metabolismo , Avaliação Pré-Clínica de Medicamentos , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Expressão Gênica/efeitos dos fármacos , Glucose/metabolismo , Homeostase/efeitos dos fármacos , Hipertrofia Ventricular Esquerda/tratamento farmacológico , Hipertrofia Ventricular Esquerda/etiologia , Hipertrofia Ventricular Esquerda/metabolismo , Insulina/sangue , Metabolismo dos Lipídeos , Masculino , Miocárdio/metabolismo , NF-kappa B/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Zucker , Receptores do Ácido Retinoico/metabolismo , Receptores X de Retinoides/metabolismo , Transdução de Sinais , Tetra-Hidronaftalenos/uso terapêutico
20.
J Lipid Res ; 54(5): 1241-54, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23427282

RESUMO

Long-chain acyl-CoA synthetases (ACSL) play key roles in fatty acid metabolism in liver and other metabolic tissues in an isozyme-specific manner. In this study, we examined the effects of a fructose-enriched diet on expressions of ACSL isoforms in the liver of hamsters. We showed that the fructose diet markedly reduced the mRNA and protein expressions of ACSL3 in hamster liver without significant effects on other ACSLs. The decrease in ACSL3 abundance was accompanied by a reduction in ACSL-catalyzed synthesis of arachidonyl-CoA and oleoyl-CoA in liver homogenates of hamsters fed the fructose diet as opposed to normal diet. We further showed that fructose diet specifically reduced expressions of three key components of the LXR signaling pathway, namely, liver X receptor (LXR)α, LXRß, and retinoid X receptor (RXR)ß. Exogenous expression and activation of LXRα/ß increased hamster ACSL3 promoter activities in a LXR-responsive element (LXRE)-dependent fashion. Finally, we showed that treating hamsters with LXR agonist GW3965 increased hepatic ACSL3 expression without affecting other ACSL isoforms. Furthermore, the ligand-induced increases of ACSL3 expression were accompanied with the reduction of hepatic triglyceride levels in GW3965-treated hamster liver. Altogether, our studies demonstrate that fructose diet has a negative impact on LXR signaling pathway in liver tissue and reduction of ACSL3 expression/activity could be a causal factor for fructose-induced hepatic steatosis.


Assuntos
Coenzima A Ligases/biossíntese , Dieta , Fígado/enzimologia , Receptores Nucleares Órfãos/metabolismo , Acil Coenzima A/biossíntese , Animais , Cricetinae , Frutose/administração & dosagem , Regulação da Expressão Gênica , Fígado/metabolismo , Receptores X do Fígado , Receptor X Retinoide beta/metabolismo , Transdução de Sinais
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA