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1.
Rheumatology (Oxford) ; 63(4): 1058-1067, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-37449908

RESUMO

OBJECTIVES: Serum urate (SU) lowering with PEGylated uricases in gout can reduce flares and tophi. However, treatment-emergent anti-drug antibodies adversely affect safety and efficacy and the currently approved PEGylated uricase pegloticase requires twice-monthly infusions. Investigational SEL-212 therapy aims to promote uricase-specific tolerance via monthly sequential infusions of a proprietary rapamycin-containing nanoparticle (ImmTOR) and pegadricase. METHODS: COMPARE was a randomized, phase 2, open-label trial of SEL-212 vs pegloticase in adults with refractory gout. SEL-212 [ImmTOR (0.15 mg/kg) and pegadricase (0.2 mg/kg)] was infused monthly or pegloticase (8 mg) twice monthly for 6 months. The primary endpoint was the proportion of participants with SU <6 mg/dl for ≥80% of the time during 3 and 6 months. Secondary outcomes were mean SU, gout flares, number of tender and/or swollen joints and safety. RESULTS: During months 3 and 6 combined, numerically more participants achieved and maintained a SU <6 mg/dl for ≥80% of the time with SEL-212 vs pegloticase (53.0% vs 46.0%, P = 0.181). The percentage reductions in SU levels were statistically greater during months 3 and 6 with SEL-212 vs pegloticase (-73.79% and -47.96%, P = 0.0161). Reductions in gout flare incidence and number of tender and/or swollen joints were comparable between treatments. There were numerical differences between the most common treatment-related adverse events of interest with SEL-212 and pegloticase: gout flares (60.2% vs 50.6%), infections (25.3% vs 18.4%) and infusion-related reactions (15.7% vs 11.5%), respectively. Stomatitis (and related terms) was experienced by eight participants (9.6%) with SEL-212 and none with pegloticase. Stomatitis, a known event for rapamycin, was associated with ImmTOR only. CONCLUSIONS: SEL-212 efficacy and tolerability were comparable to pegloticase in refractory gout. This was associated with a substantial reduction in treatment burden with SEL-212 due to decreased infusion frequency vs pegloticase. CLINICAL TRIAL REGISTRATION: NCT03905512.


Assuntos
Gota , Estomatite , Adulto , Humanos , Urato Oxidase/uso terapêutico , Urato Oxidase/efeitos adversos , Supressores da Gota/efeitos adversos , Ácido Úrico , Resultado do Tratamento , Exacerbação dos Sintomas , Polietilenoglicóis/efeitos adversos , Uricosúricos/uso terapêutico , Estomatite/induzido quimicamente , Estomatite/tratamento farmacológico
2.
J Autoimmun ; 140: 103125, 2023 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-37844543

RESUMO

Interleukin-2 (IL-2) therapies targeting the high affinity IL-2 receptor expressed on regulatory T cells (Tregs) have shown promising therapeutic benefit in autoimmune diseases through nonselective expansion of pre-existing Treg populations, but are potentially limited by the inability to induce antigen-specific Tregs, as well as by dose-limiting activation of effector immune cells in settings of inflammation. We recently developed biodegradable nanoparticles encapsulating rapamycin, called ImmTOR, which induce selective immune tolerance to co-administered antigens but do not increase total Treg numbers. Here we demonstrate that the combination of ImmTOR and an engineered Treg-selective IL-2 variant (termed IL-2 mutein) increases the number and durability of total Tregs, as well as inducing a profound synergistic increase in antigen-specific Tregs when combined with a target antigen. We demonstrate that the combination of ImmTOR and an IL-2 mutein leads to durable inhibition of antibody responses to co-administered AAV gene therapy capsid, even at sub-optimal doses of ImmTOR, and provides protection in autoimmune models of type 1 diabetes and primary biliary cholangitis. Importantly, ImmTOR also increases the therapeutic window of engineered IL-2 molecules by mitigating effector immune cell expansion and preventing exacerbation of disease in a model of graft-versus-host-disease. At the same time, IL-2 mutein shows potential for dose-sparing of ImmTOR. Overall, these results establish that the combination of ImmTOR and an IL-2 mutein show synergistic benefit on both safety and efficacy to provide durable antigen-specific immune tolerance to mitigate drug immunogenicity and to treat autoimmune diseases.

3.
Gastroenterology ; 158(5): 1334-1345.e5, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31812510

RESUMO

BACKGROUND & AIMS: Increased levels of galectin 3 have been associated with nonalcoholic steatohepatitis (NASH) and contribute to toxin-induced liver fibrosis in mice. GR-MD-02 (belapectin) is an inhibitor of galectin 3 that reduces liver fibrosis and portal hypertension in rats and was safe and well tolerated in phase 1 studies. We performed a phase 2b, randomized trial of the safety and efficacy of GR-MD-02 in patients with NASH, cirrhosis, and portal hypertension. METHODS: Patients with NASH, cirrhosis, and portal hypertension (hepatic venous pressure gradient [HVPG] ≥ 6 mm Hg) from 36 centers were randomly assigned, in a double-blind manner, to groups that received biweekly infusions of belapectin 2 mg/kg (n = 54), 8 mg/kg (n = 54), or placebo (n = 54) for 52 weeks. The primary endpoint was change in HVPG (Δ HVPG) at the end of the 52-week period compared with baseline. Secondary endpoints included changes in liver histology and development of liver-related outcomes. RESULTS: We found no significant difference in ΔHVPG between the 2 mg/kg belapectin group and placebo group (-0.28 mm HG vs 0.10 mm HG, P = 1.0) or between the 8 mg/kg belapectin and placebo group (-0.25 mm HG vs 0.10 mm HG, P = 1.0). Belapectin had no significant effect on fibrosis or nonalcoholic fatty liver disease activity score, and liver-related outcomes did not differ significantly among groups. In an analysis of a subgroup of patients without esophageal varices at baseline (n = 81), 2 mg/kg belapectin was associated with a reduction in HVPG at 52 weeks compared with baseline (P = .02) and reduced development of new varices (P = .03). Belapectin (2 mg/kg) was well tolerated and produced no safety signals. CONCLUSIONS: In a phase 2b study of 162 patients with NASH, cirrhosis, and portal hypertension, 1 year of biweekly infusion of belapectin was safe but not associated with significant reduction in HVPG or fibrosis compared with placebo. However, in a subgroup analysis of patients without esophageal varices, 2 mg/kg belapectin did reduce HVPG and development of varices. ClinicalTrials.gov number: NCT02462967.


Assuntos
Galectina 3/antagonistas & inibidores , Hipertensão Portal/tratamento farmacológico , Cirrose Hepática/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Pectinas/administração & dosagem , Idoso , Biópsia , Proteínas Sanguíneas , Método Duplo-Cego , Esquema de Medicação , Feminino , Galectina 3/metabolismo , Galectinas , Humanos , Hipertensão Portal/diagnóstico , Hipertensão Portal/etiologia , Hipertensão Portal/patologia , Infusões Intravenosas , Fígado/efeitos dos fármacos , Fígado/patologia , Cirrose Hepática/diagnóstico , Cirrose Hepática/patologia , Masculino , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/complicações , Hepatopatia Gordurosa não Alcoólica/diagnóstico , Hepatopatia Gordurosa não Alcoólica/patologia , Pectinas/efeitos adversos , Placebos/administração & dosagem , Placebos/efeitos adversos , Pressão na Veia Porta/efeitos dos fármacos , Índice de Gravidade de Doença , Resultado do Tratamento
4.
Am J Physiol Lung Cell Mol Physiol ; 316(5): L784-L797, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30724100

RESUMO

A defining characteristic of pulmonary hypertension (PH) is the extensive remodeling of pulmonary arteries (PAs), which results in progressive increases in vascular resistance and stiffness and eventual failure of the right ventricle. There is no cure for PH and identification of novel molecular mechanisms that underlie increased proliferation, reduced apoptosis, and excessive extracellular matrix production in pulmonary artery smooth muscle cells (PASMCs) is a vital objective. Galectin-3 (Gal-3) is a chimeric lectin and potent driver of many aspects of fibrosis, but its role in regulating PASMC behavior in PH remains poorly understood. Herein, we evaluated the importance of increased Gal-3 expression and signaling on PA vascular remodeling and cardiopulmonary function in experimental models of PH. Gal-3 expression was quantified by qRT-PCR, immunoblotting, and immunofluorescence imaging, and its functional role was assessed by specific Gal-3 inhibitors and CRISPR/Cas9-mediated knockout of Gal-3 in the rat. In rat models of PH, we observed increased Gal-3 expression in PASMCs, which stimulated migration and resistance to apoptosis, whereas silencing or genetic deletion reduced cellular migration and PA fibrosis and increased apoptosis. Gal-3 inhibitors attenuated and reversed PA remodeling and fibrosis, as well as hemodynamic indices in monocrotaline (MCT)-treated rats in vivo. These results were supported by genetic deletion of Gal-3 in both MCT and Sugen Hypoxia rat models. In conclusion, our results suggest that elevated Gal-3 levels contribute to inappropriate PA remodeling in PH by enhancing multiple profibrotic mechanisms. Therapeutic strategies targeting Gal-3 may be of benefit in the treatment of PH.


Assuntos
Apoptose , Proliferação de Células , Galectina 3/biossíntese , Regulação da Expressão Gênica , Hipertensão Pulmonar/metabolismo , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Fibrose Pulmonar/metabolismo , Animais , Proteínas Sanguíneas , Modelos Animais de Doenças , Galectina 3/genética , Galectinas , Humanos , Hipertensão Pulmonar/genética , Hipertensão Pulmonar/patologia , Masculino , Músculo Liso Vascular/patologia , Miócitos de Músculo Liso/patologia , Fibrose Pulmonar/genética , Fibrose Pulmonar/patologia , Ratos , Ratos Sprague-Dawley
5.
Glycobiology ; 26(1): 88-99, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26646771

RESUMO

Galectin-3 (Gal-3) is a multifunctional lectin, unique to galectins by the presence of a long N-terminal tail (NT) off of its carbohydrate recognition domain (CRD). Many previous studies have investigated binding of small carbohydrates to its CRD. Here, we used nuclear magnetic resonance spectroscopy ((15)N-(1)H heteronuclear single quantum coherence data) to assess binding of (15)N-Gal-3 (and truncated (15)N-Gal-3 CRD) to several, relatively large polysaccharides, including eight varieties of galactomannans (GMs), as well as a ß(1 → 4)-polymannan and an α-branched mannan. Overall, we found that these polysaccharides with a larger carbohydrate footprint interact primarily with a noncanonical carbohydrate-binding site on the F-face of the Gal-3 CRD ß-sandwich, and to a less extent, if at all, with the canonical carbohydrate-binding site on the S-face. While there is no evidence for interaction with the NT itself, it does appear that the NT somehow mediates stronger interactions between the Gal-3 CRD and the GMs. Significant Gal-3 resonance broadening observed during polysaccharide titrations indicates that interactions occur in the intermediate exchange regime, and analysis of these data allows estimation of affinities and stoichiometries that range from 4 × 10(4) to 12 × 10(4) M(-1) per site and multiple sites per polysaccharide, respectively. We also found that lactose can still bind to the CRD S-face of GM-bound Gal-3, with the binding of one ligand attenuating affinity of the other. These data are compared with previous results on Gal-1, revealing differences and similarities. They also provide research direction to the development of these polysaccharides as galectin-targeting therapeutics in the clinic.


Assuntos
Galectina 3/química , Mananas/metabolismo , Processamento de Proteína Pós-Traducional , Sequência de Aminoácidos , Sítios de Ligação , Sequência de Carboidratos , Galactose/análogos & derivados , Galectina 3/metabolismo , Glicosilação , Humanos , Mananas/química , Dados de Sequência Molecular , Ligação Proteica
7.
Rheumatol Ther ; 10(4): 825-847, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37069364

RESUMO

INTRODUCTION: SEL-212 is a developmental treatment for uncontrolled gout characterized by serum uric acid (sUA) levels ≥ 6 mg/dl despite treatment. It comprises a novel PEGylated uricase (SEL-037; also called pegadricase) co-administered with tolerogenic nanoparticles containing sirolimus (rapamycin) (SEL-110; also called ImmTOR®), which mitigates the formation of anti-drug antibodies (ADAs) against uricase and SEL-037 (PEGylated uricase), thereby enabling sustained sUA control (sUA < 6 mg/dl). The aim of this study was to identify appropriate dosing for SEL-037 and SEL-110 for use in phase 3 clinical trials. METHODS: This open-label phase 2 study was conducted in adults with symptomatic gout and sUA ≥ 6 mg/dl. Participants received five monthly infusions of SEL-037 (0.2 or 0.4 mg/kg) alone or in combination with three or five monthly infusions of SEL-110 (0.05-0.15 mg/kg). Safety, tolerability, sUA, ADAs, and tophi were monitored for 6 months. RESULTS: A total of 152 adults completed the study. SEL-037 alone resulted in rapid sUA reductions that were not sustained beyond 30 days in most participants due to ADA formation and loss of uricase activity. Levels of ADAs decreased with increasing doses of SEL-110 up to 0.1 mg/kg, with anti-uricase titers < 1080 correlating with sustained sUA control and reductions in tophi. Overall, 66% of evaluable participants achieved sUA control at week 20 following five monthly doses of SEL-037 0.2 mg/kg + SEL-110 0.1-0.15 mg/kg, whereas only 26% achieved sUA control at week 20 when SEL-110 was withdrawn after week 12. Compared to other dose combinations, SEL-037 0.2 mg/kg + SEL-110 0.15 mg/kg achieved the greatest sUA control at week 12 and was well-tolerated with no safety concerns. CONCLUSION: Results provide continued support for the use of multiple monthly administrations of SEL-037 0.2 mg/kg + SEL-110 0.1-0.15 mg/kg in clinical trials for SEL-212. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT02959918.

9.
Oncoimmunology ; 10(1): 1892265, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33717655

RESUMO

Treatment with an agonist anti-OX40 antibody (aOX40) boosts anti-tumor immunity by providing costimulation and driving effector T cell responses. However, tumor-induced immune suppression contributes significantly to poor response rates to aOX40 therapy, thus combining aOX40 with other agents that relieve tumor-mediated immune suppression may significantly improve outcomes. Once such target is galectin-3 (Gal-3), which drives tumor-induced immunosuppression by increasing macrophage infiltration and M2 polarization, restricting TCR signaling, and inducing T cell apoptosis. A wide-variety of tumors also upregulate Gal-3, which is associated with poor prognosis. Tumor-bearing (MCA-205 sarcoma, 4T1 mammary carcinoma, TRAMP-C1 prostate adenocarcinoma) mice were treated with a Gal-3 inhibitor (belapectin; GR-MD-02), aOX40, or combination therapy and the extent of tumor growth was determined. The phenotype and function of tumor-infiltrating lymphocytes was determined by flow cytometry, multiplex cytokine assay, and multiplex immunohistochemistry. Gal-3 inhibition synergized with aOX40 to promote tumor regression and increase survival. Specifically, aOX40/belapectin therapy significantly improved survival of tumor-bearing mice through a CD8+ T cell-dependent mechanism. Combination aOX40/belapectin therapy enhanced CD8+ T cell density within the tumor and reduced the frequency and proliferation of regulatory Foxp3+CD4+ T cells. Further, aOX40/belapectin therapy significantly reduced monocytic MDSC (M-MDSCs) and MHC-IIhi macrophage populations, both of which displayed reduced arginase 1 and increased iNOS. Combination aOX40/belapectin therapy alleviated M-MDSC-specific functional suppression compared to M-MDSCs isolated from untreated tumors. Our data suggests that Gal-3 inhibition plus aOX40 therapy reduces M-MDSC-meditated immune suppression thereby increasing CD8+ T cell recruitment leading to increased tumor regression and survival.


Assuntos
Antineoplásicos , Células Supressoras Mieloides , Neoplasias da Próstata , Animais , Galectina 3/genética , Humanos , Masculino , Camundongos , Microambiente Tumoral
10.
J Immunother Cancer ; 9(4)2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33837055

RESUMO

BACKGROUND: PD-1/PD-L1 engagement and overexpression of galectin-3 (Gal-3) are critical mechanisms of tumor-induced immune suppression that contribute to immunotherapy resistance. We hypothesized that Gal-3 blockade with belapectin (GR-MD-02) plus anti-PD-1 (pembrolizumab) would enhance tumor response in patients with metastatic melanoma (MM) and head and neck squamous cell carcinoma (HNSCC). METHODS: We performed a phase I dose escalation study of belapectin+pembrolizumab in patients with advanced MM or HNSCC (NCT02575404). Belapectin was administered at 2, 4, or 8 mg/kg IV 60 min before pembrolizumab (200 mg IV every 3 weeks for five cycles). Responding patients continued pembrolizumab monotherapy for up to 17 cycles. Main eligibility requirements were a functional Eastern Cooperative Oncology Group status of 0-2, measurable or assessable disease, and no active autoimmune disease. Prior T-cell checkpoint antibody therapy was permitted. RESULTS: Objective response was observed in 50% of MM (7/14) and and 33% of HNSCC (2/6) patients. Belapectin+pembrolizumab was associated with fewer immune-mediated adverse events than anticipated with pembrolizumab monotherapy. There were no dose-limiting toxicities for belapectin within the dose range investigated. Significantly increased effector memory T-cell activation and reduced monocytic myeloid-derived suppressor cells (M-MDSCs) were observed in responders compared with non-responders. Increased baseline expression of Gal-3+ tumor cells and PD-1+CD8+ T cells in the periphery correlated with response as did higher serum trough levels of pembrolizumab. CONCLUSIONS: Belapectin+pembrolizumab therapy has activity in MM and HNSCC. Increased Gal-3 expression, expansion of effector memory T cells, and decreased M-MDSCs correlated with clinical response. Further investigation is planned.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Proteínas Sanguíneas/antagonistas & inibidores , Galectinas/antagonistas & inibidores , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Inibidores de Checkpoint Imunológico/uso terapêutico , Mieloma Múltiplo/tratamento farmacológico , Pectinas/uso terapêutico , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Adulto , Idoso , Anticorpos Monoclonais Humanizados/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Proteínas Sanguíneas/imunologia , Feminino , Galectinas/imunologia , Neoplasias de Cabeça e Pescoço/diagnóstico , Neoplasias de Cabeça e Pescoço/imunologia , Humanos , Inibidores de Checkpoint Imunológico/efeitos adversos , Masculino , Células T de Memória/efeitos dos fármacos , Células T de Memória/imunologia , Pessoa de Meia-Idade , Mieloma Múltiplo/diagnóstico , Mieloma Múltiplo/imunologia , Células Supressoras Mieloides/efeitos dos fármacos , Células Supressoras Mieloides/imunologia , Pectinas/efeitos adversos , Receptor de Morte Celular Programada 1/imunologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/diagnóstico , Carcinoma de Células Escamosas de Cabeça e Pescoço/imunologia , Fatores de Tempo , Resultado do Tratamento
11.
PLoS One ; 13(9): e0203054, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30192782

RESUMO

BACKGROUND: Given the worldwide prevalence of NAFLD and NASH, there is a need to develop treatments to slow or reverse disease progression. GR-MD-02 (galactoarabino-rhamnogalaturonate) has been shown to reduce hepatic fibrosis in animal studies, and lower serum biomarkers of NASH fibrogenesis in humans. The primary aim of this study was to determine the difference between four-months of treatment with GR-MD-02 or placebo in liver inflammation and fibrosis as measured by iron-corrected T1 (cT1) mapping, a non-invasive magnetic resonance imaging (MRI) biomarker that correlates with the extent of hepatic fibro-inflammatory disease. The secondary aims were to determine change in liver stiffness as measured by magnetic resonance elastography (MRE) and shear-wave ultrasonic elastography (LSM), and to explore test-retest repeatability of the three biomarkers. MATERIALS AND METHODS: Thirty subjects (13 females, 46-71 years) with NASH and advanced fibrosis were recruited. Subjects were randomized to receive 8 mg.kg-1 GR-MD-02 (via IV infusion) or placebo, administered biweekly over a 16-week period. Therapeutic efficacy was examined using cT1, MRE, and LSM. Statistical analyses on group differences in the biomarkers were performed using robust ANCOVA models adjusting for baseline measurement and additional covariates. RESULTS: There was no significant difference in cT1 (p = 0.16) between GR-MD-02 and placebo groups following a 16-week intervention. There was also no significant difference in liver stiffness, measured by MRE (p = 0.80) or LSM (p = 0.63), between groups. Examination of repeatability of the cT1, MRE and LSM revealed coefficient of variations of 3.1%, 11% and 40% respectively. CONCLUSIONS: 8 mg.kg-1 of GR-MD-02 had no significant effect on non-invasive biomarkers of liver inflammation or fibrosis over a 4-month period. Histological confirmation was not available in this study. The high reproducibility of the primary outcome measure suggests that cT1 could be utilized for monitoring longitudinal change in patients with NASH.


Assuntos
Cirrose Hepática/diagnóstico por imagem , Cirrose Hepática/tratamento farmacológico , Imageamento por Ressonância Magnética , Pectinas/uso terapêutico , Substâncias Protetoras/uso terapêutico , Ultrassonografia , Idoso , Método Duplo-Cego , Elasticidade , Feminino , Humanos , Fígado/diagnóstico por imagem , Fígado/efeitos dos fármacos , Cirrose Hepática/fisiopatologia , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/diagnóstico por imagem , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/fisiopatologia , Resultado do Tratamento , Ultrassonografia/métodos
12.
Mol Cell Biol ; 22(15): 5467-78, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12101240

RESUMO

Intestinal gene regulation involves mechanisms that direct temporal expression along the vertical and horizontal axes of the alimentary tract. Sucrase-isomaltase (SI), the product of an enterocyte-specific gene, exhibits a complex pattern of expression. Generation of transgenic mice with a mutated SI transgene showed involvement of an overlapping CDP (CCAAT displacement protein)-GATA element in colonic repression of SI throughout postnatal intestinal development. We define this element as CRESIP (colon-repressive element of the SI promoter). Cux/CDP interacts with SI and represses SI promoter activity in a CRESIP-dependent manner. Cux/CDP homozygous mutant mice displayed increased expression of SI mRNA during early postnatal development. Our results demonstrate that an intestinal gene can be repressed in the distal gut and identify Cux/CDP as a regulator of this repression during development.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Mucosa Intestinal/metabolismo , Proteínas Nucleares/metabolismo , Sequências Reguladoras de Ácido Nucleico/fisiologia , Proteínas Repressoras/metabolismo , Complexo Sacarase-Isomaltase/genética , Envelhecimento/metabolismo , Animais , Células COS , Células CACO-2 , Colo/citologia , Colo/crescimento & desenvolvimento , Colo/metabolismo , Proteínas de Ligação a DNA/metabolismo , Fator de Transcrição GATA4 , Proteínas de Homeodomínio , Humanos , Hibridização In Situ , Intestino Delgado/citologia , Intestino Delgado/crescimento & desenvolvimento , Intestino Delgado/metabolismo , Intestinos/citologia , Intestinos/crescimento & desenvolvimento , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Mutagênese Sítio-Dirigida , Regiões Promotoras Genéticas/fisiologia , RNA Mensageiro/metabolismo , Complexo Sacarase-Isomaltase/biossíntese , Fatores de Transcrição/metabolismo , Transgenes
13.
Acad Med ; 82(8): 757-62, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17762249

RESUMO

Hurricane Katrina was one of the greatest natural disasters to ever strike the United States. Tulane University School of Medicine, located in downtown New Orleans, and its three major teaching hospitals were flooded in the aftermath of the storm and forced to close. Faculty, students, residents, and staff evacuated to locations throughout the country. All critical infrastructure that normally maintained the school, including information technology, network communication servers, registration systems, and e-mail, became nonoperational. However, on the basis of experiences learned when Tropical Storm Allison flooded the Texas Medical Center in 2001, Baylor College of Medicine, University of Texas-Houston, University of Texas Medical Branch in Galveston, and Texas A&M School of Medicine created the South Texas Alliance of Academic Health Centers, which allowed Tulane to move its education programs to Houston. Using Baylor's facilities, Tulane faculty rebuilt and delivered the preclinical curriculum, and clinical rotations were made available at the Alliance schools. Remarkably, the Tulane School of Medicine was able to resume all educational activities within a month after the storm. Educational reconstruction approaches, procedures employed, and lessons in institutional recovery learned are discussed so that other schools can prepare effectively for either natural or man-made disasters. Key disaster-response measures include designating an evacuation/command site in advance; backing up technology, communication, financial, registration, and credentialing systems; and establishing partnership with other institutions and leaders.


Assuntos
Desastres , Educação de Graduação em Medicina/organização & administração , Faculdades de Medicina/organização & administração , Planejamento em Desastres , Louisiana
14.
Oncogene ; 22(41): 6395-407, 2003 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-14508520

RESUMO

The transcription factor Cdx1 regulates intestine-specific gene expression and enterocyte differentiation. It has been hypothesized to play a role in regulating intestinal cell proliferation; however, the mechanism for this effect remains elusive. In a prior study, we demonstrated that Cdx1 expression reduced the proliferation of a nontransformed intestinal cell line. This study tests the hypothesis that Cdx1 expression inhibits colon cancer cell proliferation by reducing cyclin D1 gene expression. Cdx1 expression markedly reduced cancer cell proliferation and DNA synthesis and induced an accumulation of cells in G0/G1. A transcriptionally inactive Cdx1 mutant could not elicit this effect, suggesting that it required Cdx1 transcriptional activity. Cdx1 expression increased the hypophosphorylation of the retinoblastoma (pRb) and p130 proteins. Reductions in G1 cyclin-dependant kinase (cdk) activity accompanied this effect. Cyclin D1 mRNA and protein levels were diminished by Cdx1 expression. Restoration of cyclin D1 expression reversed the G0/G1 block and induced pRb hyperphosphorylation. Lastly, Cdx1 expression did not alter cyclin D1 mRNA stability but did reduce cyclin D1 promoter activity, suggesting that Cdx1 acts to diminish cyclin D1 gene transcription. We conclude that Cdx1 reduces the proliferation of human colon cancer cells by reducing cyclin D1 gene transcription.


Assuntos
Divisão Celular/fisiologia , Neoplasias do Colo/metabolismo , Ciclina D1/genética , Proteínas de Homeodomínio/metabolismo , Animais , Ciclo Celular/fisiologia , Ciclina D1/biossíntese , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , RNA Mensageiro/metabolismo , Células Tumorais Cultivadas
15.
PLoS One ; 8(12): e83481, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24367597

RESUMO

Non-alcoholic steatohepatitis (NASH) and resultant liver fibrosis is a major health problem without effective therapy. Some data suggest that galectin-3 null mice are resistant to the development of NASH with fibrosis. We examined the ability of two complex carbohydrate drugs that bind galectin-3, GM-CT-01 and GR-MD-02, to treat NASH with fibrosis in a murine model. GR-MD-02 treatment resulted in marked improvement in liver histology with significant reduction in NASH activity and collagen deposition. Treatments seemed also to improve both glomerulopathy and interstitial fibrosis observed in kidneys. The improvement in liver histology was evident when animals were treated early in disease or after establishment of liver fibrosis. In all measures, GM-CT-01 had an intermediate effect between vehicle and GR-MD-02. Galectin-3 protein expression was increased in NASH with highest expression in macrophages surrounding lipid laden hepatocytes, and reduced following treatment with GR-MD-02, while the number of macrophages was unchanged. Treatment with GR-MD-02 also reduced the expression of pathological indicators including iNOS, an important TH1 inflammatory mediator, CD36, a scavenger receptor for lipoproteins on macrophages, and α-smooth muscle actin, a marker for activated stellate cells which are the primary collagen producing cells in liver fibrosis. We conclude that treatment with these galectin-3 targeting drugs improved histopathological findings of NASH and markedly reduced fibrosis in a murine model of NASH. While the mechanisms require further investigation, the treatment effect is associated with a reduction of galectin-3 expressed by activated macrophages which was associated with regression of NASH, including hepatocellular fat accumulation, hepatocyte ballooning, intra-portal and intra-lobular inflammatory infiltrate, and deposition of collagen. Similar effects were found with GM-CT-01, but with approximately four-fold lower potency than GR-MD-02. The results, in combination with previous experiments in toxin-induced fibrosis, suggest that these galectin-targeting drugs may have potential in human NASH with fibrosis.


Assuntos
Carboidratos/farmacologia , Fígado Gorduroso/tratamento farmacológico , Galectinas/antagonistas & inibidores , Cirrose Hepática/tratamento farmacológico , Animais , Antígenos CD36/metabolismo , Carboidratos/efeitos adversos , Carboidratos/química , Carboidratos/uso terapêutico , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Fígado Gorduroso/metabolismo , Fígado Gorduroso/patologia , Feminino , Células Estreladas do Fígado/efeitos dos fármacos , Rim/efeitos dos fármacos , Cirrose Hepática/metabolismo , Cirrose Hepática/patologia , Camundongos , Óxido Nítrico Sintase Tipo II/metabolismo , Hepatopatia Gordurosa não Alcoólica , Gravidez , Fatores de Tempo
16.
PLoS One ; 8(10): e75361, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24130706

RESUMO

Galectin-3 protein is critical to the development of liver fibrosis because galectin-3 null mice have attenuated fibrosis after liver injury. Therefore, we examined the ability of novel complex carbohydrate galectin inhibitors to treat toxin-induced fibrosis and cirrhosis. Fibrosis was induced in rats by intraperitoneal injections with thioacetamide (TAA) and groups were treated with vehicle, GR-MD-02 (galactoarabino-rhamnogalaturonan) or GM-CT-01 (galactomannan). In initial experiments, 4 weeks of treatment with GR-MD-02 following completion of 8 weeks of TAA significantly reduced collagen content by almost 50% based on Sirius red staining. Rats were then exposed to more intense and longer TAA treatment, which included either GR-MD-02 or GM-CT-01 during weeks 8 through 11. TAA rats treated with vehicle developed extensive fibrosis and pathological stage 6 Ishak fibrosis, or cirrhosis. Treatment with either GR-MD-02 (90 mg/kg ip) or GM-CT-01 (180 mg/kg ip) given once weekly during weeks 8-11 led to marked reduction in fibrosis with reduction in portal and septal galectin-3 positive macrophages and reduction in portal pressure. Vehicle-treated animals had cirrhosis whereas in the treated animals the fibrosis stage was significantly reduced, with evidence of resolved or resolving cirrhosis and reduced portal inflammation and ballooning. In this model of toxin-induced liver fibrosis, treatment with two galectin protein inhibitors with different chemical compositions significantly reduced fibrosis, reversed cirrhosis, reduced galectin-3 expressing portal and septal macrophages, and reduced portal pressure. These findings suggest a potential role of these drugs in human liver fibrosis and cirrhosis.


Assuntos
Fibrose/tratamento farmacológico , Galactanos/uso terapêutico , Galectinas/antagonistas & inibidores , Cirrose Hepática/tratamento farmacológico , Hepatopatias/tratamento farmacológico , Mananas/uso terapêutico , Pectinas/uso terapêutico , Tioacetamida/toxicidade , Animais , Apoptose/efeitos dos fármacos , Western Blotting , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Galactose/análogos & derivados , Humanos , Masculino , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa
17.
J Biol Chem ; 277(39): 35795-800, 2002 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-12124393

RESUMO

CDX1 is a homeobox protein that inhibits proliferation of intestinal epithelial cells and regulates intestine-specific genes involved in differentiation. CDX1 expression is developmentally and spatially regulated, and its expression is aberrantly down-regulated in colorectal cancers and colon cancer-derived cell lines. However, very little is known about the molecular mechanism underlying the regulation of CDX1 gene expression. In this study, we characterized the CDX1 gene structure and identified that its gene promoter contained a typical CpG island with a CpG observed/expected ratio of 0.80, suggesting that the CDX1 gene is a target of aberrant methylation. Alterations of DNA methylation in the CDX1 gene promoter were investigated in a series of colorectal cancer cell lines. Combined Bisulfite Restriction Analysis (COBRA) and bisulfite sequencing analysis revealed that the CDX1 promoter is methylated in CDX1 non-expressing colorectal cancer cell lines but not in human normal colon tissue and T84 cells, which express CDX1. Treatment with 5'-aza-2'-deoxycytidine (5-azaC), a DNA methyltransferase inhibitor, induced CDX1 expression in the colorectal cancer cell lines. Furthermore, de novo methylation was determined by establishing stably transfected clones of the CDX1 promoter in SW480 cells and demethylation by 5-azaC-activated reporter gene expression. These results indicate that aberrant methylation of the CpG island in the CDX1 promoter is one of the mechanisms that mediate CDX1 down-regulation in colorectal cancer cell lines.


Assuntos
Azacitidina/análogos & derivados , Neoplasias Colorretais/genética , Metilação de DNA , Regulação para Baixo , Animais , Azacitidina/farmacologia , Sequência de Bases , Western Blotting , Clonagem Molecular , Neoplasias Colorretais/metabolismo , Cosmídeos/metabolismo , Ilhas de CpG , Decitabina , Inibidores Enzimáticos/farmacologia , Células HeLa , Humanos , Camundongos , Dados de Sequência Molecular , Plasmídeos/metabolismo , Regiões Promotoras Genéticas , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sulfitos/farmacologia , Transfecção , Células Tumorais Cultivadas
18.
J Biol Chem ; 277(35): 31909-17, 2002 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-12060663

RESUMO

Sucrase-isomaltase (SI), an intestine-specific gene, is induced in the differentiated small intestinal villous epithelium during the suckling-weaning transition in mice. We have previously identified cis-acting elements within a short evolutionarily conserved SI promoter. However, the nature and profile of expression of the interacting proteins have not been fully characterized during this developmental transition. Herein, we show that hepatocyte nuclear factor-1 alpha (HNF-1 alpha), GATA-4, and caudal related homeodomain proteins Cdx2 and Cdx1 are the primary transcription factors from the adult mouse intestinal epithelium to interact with the SIF3, GATA, and SIF1 elements of the SI promoter. We wanted to study whether HNF-1 alpha, GATA-4, and Cdx2 can cooperate in the regulation of SI gene expression. Immunolocalization experiments revealed that HNF-1 alpha is detected in rare epithelial cells of suckling mice and becomes progressively more expressed in the villous epithelial cells during the suckling-weaning transition. GATA-4 protein is expressed exclusively in villous differentiated epithelial cells of the proximal small intestine, decreases in expression in the ileum, and becomes undetectable in the colon. HNF-1 alpha, GATA-4, and Cdx2 interact in vitro and in vivo. These factors activate SI promoter activity in cotransfection experiments where GATA-4 requires the presence of both HNF-1 alpha and Cdx2. These findings imply a combinatory role of HNF-1 alpha, Cdx2, and GATA-4 for the time- and position-dependent regulation of SI transcription during development.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Regulação Enzimológica da Expressão Gênica , Proteínas de Homeodomínio/metabolismo , Mucosa Intestinal/enzimologia , Proteínas Nucleares , Complexo Sacarase-Isomaltase/genética , Fatores de Transcrição/metabolismo , Transcrição Gênica , Animais , Sequência de Bases , Fator de Transcrição CDX2 , Fator de Transcrição GATA4 , Genes Reporter , Fator 1 Nuclear de Hepatócito , Fator 1-alfa Nuclear de Hepatócito , Fator 1-beta Nuclear de Hepatócito , Mucosa Intestinal/crescimento & desenvolvimento , Luciferases/genética , Camundongos , Camundongos Transgênicos , Microvilosidades/enzimologia , Regiões Promotoras Genéticas , Transativadores , Dedos de Zinco
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