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1.
N Engl J Med ; 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38847460

RESUMO

BACKGROUND: Dual agonism of glucagon receptor and glucagon-like peptide-1 (GLP-1) receptor may be more effective than GLP-1 receptor agonism alone for treating metabolic dysfunction-associated steatohepatitis (MASH). The efficacy and safety of survodutide (a dual agonist of glucagon receptor and GLP-1 receptor) in persons with MASH and liver fibrosis are unclear. METHODS: In this 48-week, phase 2 trial, we randomly assigned adults with biopsy-confirmed MASH and fibrosis stage F1 through F3 in a 1:1:1:1 ratio to receive once-weekly subcutaneous injections of survodutide at a dose of 2.4, 4.8, or 6.0 mg or placebo. The trial had two phases: a 24-week rapid-dose-escalation phase, followed by a 24-week maintenance phase. The primary end point was histologic improvement (reduction) in MASH with no worsening of fibrosis. Secondary end points included a decrease in liver fat content by at least 30% and biopsy-assessed improvement (reduction) in fibrosis by at least one stage. RESULTS: A total of 293 randomly assigned participants received at least one dose of survodutide or placebo. Improvement in MASH with no worsening of fibrosis occurred in 47% of the participants in the survodutide 2.4-mg group, 62% of those in the 4.8-mg group, and 43% of those in the 6.0-mg group, as compared with 14% of those in the placebo group (P<0.001 for the quadratic dose-response curve as best-fitting model). A decrease in liver fat content by at least 30% occurred in 63% of the participants in the survodutide 2.4-mg group, 67% of those in the 4.8-mg group, 57% of those in the 6.0-mg group, and 14% of those in the placebo group; improvement in fibrosis by at least one stage occurred in 34%, 36%, 34%, and 22%, respectively. Adverse events that were more frequent with survodutide than with placebo included nausea (66% vs. 23%), diarrhea (49% vs. 23%), and vomiting (41% vs. 4%); serious adverse events occurred in 8% with survodutide and 7% with placebo. CONCLUSIONS: Survodutide was superior to placebo with respect to improvement in MASH without worsening of fibrosis, warranting further investigation in phase 3 trials. (Funded by Boehringer Ingelheim; 1404-0043 ClinicalTrials.gov number, NCT04771273; EudraCT number, 2020-002723-11.).

2.
J Hepatol ; 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38857788

RESUMO

BACKGROUND & AIMS: Survodutide is a glucagon/glucagon-like peptide-1 receptor dual agonist in development for treatment of metabolic dysfunction-associated steatohepatitis (MASH). We investigated survodutide in people with cirrhosis. METHODS: This multinational, non-randomized, open-label, phase 1 clinical trial initially evaluated a single subcutaneous (s.c.) dose of survodutide 0.3 mg in people with Child-Pugh class A, B or C cirrhosis and healthy individuals with or without overweight/obesity matched for age, sex, and weight; the primary endpoints were the area under the plasma concentration-time curve from 0 to infinity (AUC0-∞) and maximal plasma concentration (Cmax). Subsequently, people with overweight/obesity with or without cirrhosis and Child-Pugh class A or B received once-weekly s.c. doses escalated from 0.3 mg to 6.0 mg over 24 weeks then maintained for 4 weeks; the primary endpoint was drug-related treatment-emergent adverse events, with MASH/cirrhosis-related endpoints explored. RESULTS: In the single-dose cohorts (n = 41), mean AUC0-∞ and Cmax were similar in those with cirrhosis compared with healthy individuals (90% confidence intervals for adjusted geometric mean ratios spanned 1). Drug-related adverse events occurred in 25.0% of healthy individuals and ≤25.0% of those with cirrhosis after single doses, and 82.4% and 87.5%, respectively, of the multiple-dose cohorts (n = 41) over 28 weeks. Liver fat content, liver stiffness, liver volume, body weight, and other hepatic and metabolic disease markers were generally reduced after 28 weeks of survodutide treatment. CONCLUSIONS: Survodutide is generally tolerable in people with compensated or decompensated cirrhosis, does not require pharmacokinetic-related dose adjustment, and may improve liver-related non-invasive tests, supporting its investigation for MASH-related cirrhosis. Clinical trial number; ClinicalTrials.gov identifier: NCT05296733. IMPACT AND IMPLICATIONS: Survodutide is a glucagon receptor/glucagon-like peptide-1 receptor dual agonist in development for treatment of metabolic dysfunction-associated steatohepatitis (MASH), which causes cirrhosis in ∼20% of cases. This trial delineates the pharmacokinetic and safety profile of survodutide in people with compensated or decompensated cirrhosis, and revealed associated reductions in liver fat content, markers of liver fibrosis and body weight. These findings have potential relevance for people with MASH-including those with decompensated cirrhosis, who are usually excluded from clinical trials of investigational drugs. Based on this study, further investigation of survodutide for MASH-related cirrhosis is warranted.

3.
Data Brief ; 25: 104030, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31440534

RESUMO

Wind turbine blades (WTB) mechanically recycled and used as a feedstock for thermoplastic composites. Physical properties (water sorption (WA), Thickness swelling (TS)) dataset of composites made from recycled wind turbine blades presented. Dataset also presented the influence of resin level, mill screen size and coupling agents on the physical properties of composites (Mamanpush et al., 2019).

4.
Data Brief ; 25: 104253, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31384646

RESUMO

The wind turbine blades (WTB) that face end-of-life was first mechanically milled and classified through a range of varying screen sizes. We then blended this with high density polyethylene (HDPE) thermoplastic resin and extruded it to a profiled composite. We determined the influence of refined particle size, resin content and coupling agents (maleic anhydride polyethylene (MAPE) and methacryloxypropyltriethoxysilane (Silane)) on the mechanical and CLTE properties of recycled composites (Mamanpush et al., 2019).

5.
Data Brief ; 20: 658-661, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30211255

RESUMO

Wind turbine blades that face end-of-life recycled mechanically. The recycled material was first comminuted via a hammer-mill through a range of varying screen sizes, resinated and compressed to a final thickness to manufacture second generation composites fabricated using recycled wind turbine material and a polyurethane adhesive. Physical properties (water sorption (WA), Thickness swelling (TS)) dataset of composites made from recycled wind turbine blades presented. Dataset also presented the influence of resin level, moisture content, mill screen size and density on the physical properties of composites.

6.
Data Brief ; 19: 230-235, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29892638

RESUMO

Wind turbine blades that face end-of-life recycled mechanically. The recycled material was first comminuted via a hammer-mill through a range of varying screen sizes, resonated (polymeric Methylene diphenyl isocyanate (pMDI)) and then hand-formed and hot pressed. The hot press temperature and time were set as 138 °C and 5 min accordingly, typical for pMDI composite processing. Mechanical properties (Modulus of rupture (MOR), Module of elasticity (MOE) and Internal bond(IB)) dataset of composites made from recycled wind turbine blades(rWTBs) presented. Dataset also presented the influence of resin level, moisture content, mill screen size and density on the mechanical properties of composites [1], [2].

7.
Mol Cell Endocrinol ; 477: 48-56, 2018 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-29883690

RESUMO

Overexpression of the X-linked inhibitor of apoptosis (XIAP) prevents islet allograft rejection. We constructed an adeno-associated virus expressing XIAP driven by the rat insulin promoter (dsAAV8-RIP-XIAP) for long-term beta-cell gene expression in vivo. Pancreatic delivery of dsAAV8-RIP-XIAP prevented autoimmune diabetes in 70% of non-obese diabetic (NOD) mice, associated with decreased insulitis. Islets from Balb/c mice transduced with dsAAV8-RIP-XIAP were protected following transplantation into streptozotocin (STZ)-diabetic Bl/6 recipients, associated with decreased graft infiltration. Interestingly, dsAAV8-RIP-XIAP transduction induced expression of lactate dehydrogenase (LDHA) and monocarboxylate transporter 1 (MCT1), two genes normally suppressed in beta cells and involved in production and release of lactate, a metabolite known to suppress local immune responses. Transduction of Balb/c islets with AAV8-RIP-LDHA-MCT1 tended to prolong allograft survival following transplant into STZ-diabetic Bl/6 recipients. These findings suggest that XIAP has therapeutic potential in autoimmune diabetes and raise the possibility that local lactate production may play a role in XIAP-mediated immunomodulation.


Assuntos
Aloenxertos/imunologia , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/prevenção & controle , Rejeição de Enxerto/prevenção & controle , Imunomodulação , Células Secretoras de Insulina/metabolismo , Transplante das Ilhotas Pancreáticas , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/metabolismo , Aloenxertos/efeitos dos fármacos , Aloenxertos/metabolismo , Animais , Diabetes Mellitus Tipo 1/patologia , Glucose/farmacologia , Rejeição de Enxerto/imunologia , Humanos , Tolerância Imunológica/efeitos dos fármacos , Imunomodulação/efeitos dos fármacos , Injeções , Insulina/genética , Secreção de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/efeitos dos fármacos , L-Lactato Desidrogenase/metabolismo , Ácido Láctico/biossíntese , Camundongos , Camundongos Endogâmicos NOD , Transportadores de Ácidos Monocarboxílicos/metabolismo , Ratos , Simportadores/metabolismo
8.
Waste Manag ; 76: 708-714, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29506776

RESUMO

With an increase in renewable wind energy via turbines, an underlying problem of the turbine blade disposal is looming in many areas of the world. These wind turbine blades are predominately a mixture of glass fiber composites (GFCs) and wood and currently have not found an economically viable recycling pathway. This work investigates a series of second generation composites fabricated using recycled wind turbine material and a polyurethane adhesive. The recycled material was first comminuted via a hammer-mill through a range of varying screen sizes, resinated and compressed to a final thickness. The refined particle size, moisture content and resin content were assessed for their influence on the properties of recycled composites. Static bending, internal bond and water sorption properties were obtained for all composites panels. Overall improvement of mechanical properties correlated with increase in resin content, moisture content, and particle size. The current investigation demonstrates that it is feasible and promising to recycle the wind turbine blade to fabricate value-added high-performance composite.


Assuntos
Energia Renovável , Reciclagem , Vento , Madeira
9.
Physiother Res Int ; 23(1)2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29148611

RESUMO

OBJECTIVE: The modified Tardieu Scale (MTS) is a clinical tool for the measurement of muscle spasticity. The present study aimed to investigate the relationship between the MTS and the slope of the work-velocity curve as a biomechanical measure in assessing knee extensor muscle spasticity in patients with stroke. METHODS: Thirty patients with stroke (22 female, 8 male; mean age 55.4 ± 12.0 years) participated in this study. The knee extensor spasticity was assessed with the MTS. An isokinetic dynamometer was used to move the knee passively from full extension to 90° flexion at speeds of 60°/s, 120°/s, 180°/s, and 240°/s to collect torque-angle data. The slope of the work-velocity curve was calculated using linear regression [J/(°/s)]. RESULTS: The mean of R2-R1 component of MTS was 19.73 (SD 29.85). The mean work significantly decreased as the speed increased (p < .001). The mean (SD) slope for the work-velocity curve was -0.83 (SD 0.73, range -2.6-0.3). There was no significant relationship between the R2 -R1 and the slope of work-velocity curve (r = 0.09, p = .62). CONCLUSIONS: The lack of significant relationship between the MTS and the slope of work-velocity curve may question the usefulness of the MTS as a valid measure of muscle spasticity after stroke.


Assuntos
Joelho/fisiopatologia , Espasticidade Muscular , Acidente Vascular Cerebral/fisiopatologia , Adulto , Idoso , Fenômenos Biomecânicos , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dinamômetro de Força Muscular , Avaliação de Resultados em Cuidados de Saúde , Amplitude de Movimento Articular , Torque
10.
Disabil Rehabil ; 39(5): 483-490, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-26971745

RESUMO

Purpose To examine the effects of radial extracorporeal shockwave therapy (rESWT) on plantarflexor spasticity after stroke. Method Twelve patients with stroke were randomly included for this prospective, single-blind clinical trial. Patients received one rESWT session (0.340 mJ/mm2, 2000 shots) on plantarflexor muscle. The Modified Modified Ashworth Scale (MMAS), H-reflex tests, ankle range of motion (ROM), passive plantarflexor torque (PPFT) and timed up and go test (TUG) were measured at baseline (T0), immediately after treatment (T1) and one hour after the end of the treatment (T2). Results Patients had improved the MMAS scores for both the gastrocnemius and the soleus muscles, active and passive ROM, PPFT and TUG over time after rESWT. For the PPFT, it was greater at high velocity than at low velocity, and there was a significant three-way interaction between time, knee position (extended/flexed) and velocity (low/high). The H-reflex latency had decreased at T1, but there was no significant effect on Hmax/Mmax ratio. Conclusions The rESWT improved plantarflexor spasticity, and the effects sustained for one hour, whereas it was not effective in improving spinal excitability. Implications for Rehabilitation One session radial extracorporeal shock wave therapy (rESWT) is safe and effective in improving post stroke plantarflexor spasticity, ankle active and passive range of motion, passive torque, and walking capability. The spasticity scores improved for both the gastrocnemius and the soleus muscles and persisted one hour after rESWT. The magnitude of resistive plantarflexor passive torque in the knee extended position and high velocity was larger over time suggesting greater gastrocnemius spasticity than soleus. The rESWT had no significant effects on alpha motorneuron excitability.


Assuntos
Tratamento por Ondas de Choque Extracorpóreas , Espasticidade Muscular/etiologia , Espasticidade Muscular/fisiopatologia , Espasticidade Muscular/reabilitação , Músculo Esquelético/fisiopatologia , Acidente Vascular Cerebral/complicações , Adulto , Idoso , Avaliação da Deficiência , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Amplitude de Movimento Articular/fisiologia , Método Simples-Cego , Torque , Caminhada/fisiologia
11.
PLoS One ; 11(1): e0146970, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26765526

RESUMO

Type 1 diabetes (T1D) results from autoimmune destruction of insulin producing ß cells of the pancreatic islets. Curbing autoimmunity at the initiation of T1D can result in recovery of residual ß cells and consequently remission of diabetes. Here we report a cell-based therapy for autoimmune diabetes in non-obese diabetic (NOD) mice using dermal fibroblasts. This was achieved by a single injection of fibroblasts, expressing the immunoregulatory molecule indoleamine 2,3 dioxygenase (IDO), into peritoneal cavity of NOD mice shortly after the onset of overt hyperglycemia. Mice were then monitored for reversal of hyperglycemia and changes in inflammatory/regulatory T cell profiles. Blood glucose levels dropped into the normal range in 82% of NOD mice after receiving IDO-expressing fibroblasts while all control mice remained diabetic. We found significantly reduced islet inflammation, increased regulatory T cells, and decreased T helper 17 cells and ß cell specific autoreactive CD8+ T cells following IDO cell therapy. We further showed that some of intraperitoneal injected fibroblasts migrated to local lymph nodes and expressed co-inhibitory molecules. These findings suggest that IDO fibroblasts therapy can reinstate self-tolerance and alleviate ß cell autoreactivity in NOD mice, resulting in remission of autoimmune diabetes.


Assuntos
Terapia Baseada em Transplante de Células e Tecidos , Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/metabolismo , Fibroblastos/metabolismo , Animais , Autoimunidade/genética , Autoimunidade/imunologia , Movimento Celular/genética , Movimento Celular/imunologia , Terapia Baseada em Transplante de Células e Tecidos/métodos , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/terapia , Expressão Gênica , Hiperglicemia/genética , Hiperglicemia/metabolismo , Hiperglicemia/terapia , Indolamina-Pirrol 2,3,-Dioxigenase/genética , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Células Secretoras de Insulina/metabolismo , Ilhotas Pancreáticas/imunologia , Ilhotas Pancreáticas/metabolismo , Ilhotas Pancreáticas/patologia , Linfonodos/imunologia , Linfonodos/metabolismo , Contagem de Linfócitos , Camundongos , Camundongos Endogâmicos NOD , Receptores CCR7/metabolismo , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo
12.
Transplantation ; 99(7): 1341-8, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25769070

RESUMO

BACKGROUND: We have previously shown that an immunomodulatory enzyme, indoleamine 2,3-dioxygenase (IDO) in dermal fibroblasts generates a tryptophan-deficient environment that selectively inhibits proliferation and induces apoptosis of bystander CD4+ and CD8+ T cells, but not pancreatic islets. Because these immune cells are involved in islet allograft rejection, we hypothesized that transplantation of islets embedded in a novel 3-dimensional composite scaffold within which stable IDO-expressing fibroblasts serve as source of local immunosuppression would lead to normoglycemia in a streptozotocin-induced diabetic mouse model. METHODS: Islet grafts were prepared by embedding stable IDO-expressing fibroblasts and allogeneic islets into a protease-resistant composite scaffold. Islets function and survival were evaluated in vitro using immunohistochemistry. Allografts were transplanted under the kidney capsule of streptozotocin-induced diabetic mice; viability, function, and criteria for graft take were evaluated. Flow cytometry was performed to determine specific intragraft, draining lymph nodes and spleen T-cell population, and splenocytes alloantigen responsiveness of graft recipients. RESULTS: The results of a series of in vitro experiments revealed that IDO-expressing fibroblasts do not compromise islet function or survival. The expression of IDO suppressed the proliferation of alloantigen-stimulated splenocytes. The in vivo experiments revealed that local IDO expression delivered by lentiviral vector prolonged islet allograft survival (51.0 ± 2.9 days) by increasing the population of FOXP3+ regulatory T cells at the graft site and graft-draining lymph nodes and preventing T-cell infiltration. CONCLUSIONS: This study shows that incorporation of islets within our novel matrix that is equipped with stable IDO-expressing fibroblasts prolongs allograft survival.


Assuntos
Diabetes Mellitus Experimental/terapia , Fibroblastos/transplante , Terapia Genética/métodos , Indolamina-Pirrol 2,3,-Dioxigenase/biossíntese , Transplante das Ilhotas Pancreáticas/métodos , Ilhotas Pancreáticas/cirurgia , Alicerces Teciduais , Animais , Biomarcadores/sangue , Glicemia/metabolismo , Proliferação de Células , Células Cultivadas , Técnicas de Cocultura , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/enzimologia , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/imunologia , Fibroblastos/enzimologia , Fibroblastos/imunologia , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/prevenção & controle , Sobrevivência de Enxerto , Indolamina-Pirrol 2,3,-Dioxigenase/genética , Ilhotas Pancreáticas/enzimologia , Ilhotas Pancreáticas/imunologia , Linfonodos/enzimologia , Linfonodos/imunologia , Ativação Linfocitária , Masculino , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Baço/enzimologia , Baço/imunologia , Linfócitos T/enzimologia , Linfócitos T/imunologia , Fatores de Tempo , Técnicas de Cultura de Tecidos , Transfecção
13.
Tissue Eng Part A ; 21(5-6): 1085-94, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25412924

RESUMO

Wound repair requires a sequential series of biological events that begins with the deposition of a temporary scaffold within which cells can repair the skin. Without a scaffold, repair is essentially impossible. Aberrant wound healing, such as hypertrophic scarring or nonhealing, has a tremendous burden on healthcare and quality of life. Timely wound closure dramatically reduces the risk of infection and scarring. Cellular skin substitutes are opportune to meet this need. Our goal was to create an in-situ forming scaffold that can be easily combined with cells to rapidly form a dermal substitute within the wound bed. In this study, we evaluated the application of a polyvinyl alcohol-collagen-glycosaminoglycan-based biohybrid scaffold system in full-thickness wounds on a rabbit fibrotic ear model. Punch wounds (6 mm) were either untreated or filled with an acellular scaffold, a scaffold containing xenofibroblasts, or a scaffold containing xenofibroblasts expressing indoleamine 2,3-dioxygenase (IDO). Results demonstrated that (1) both acellular and IDO-expressing fibroblast in-situ forming scaffolds significantly reduced scar elevation index (1.24±0.05 and 1.25±0.03; p<0.05) and improved overall healing quality compared with xenofibroblast scaffolds and untreated wounds; (2) IDO-expressing fibroblast scaffolds significantly reduced T-cell infiltration into the scaffold-engrafted area (p<0.05); and (3) both IDO-expressing and acellular in-situ forming scaffolds demonstrated increased vessel-like and nerve-like structures (p<0.05). The results demonstrated that the use of the in-situ forming scaffold, and even more so when delivering IDO-expressing cells, improved healing outcome in full-thickness hypertrophic rabbit ear wounds.


Assuntos
Pele Artificial , Cicatrização , Adulto , Animais , Materiais Biocompatíveis/farmacologia , Complexo CD3/metabolismo , Forma Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Criança , Cicatriz Hipertrófica , Colágeno Tipo I/metabolismo , Modelos Animais de Doenças , Orelha/patologia , Matriz Extracelular/efeitos dos fármacos , Matriz Extracelular/metabolismo , Fibroblastos/efeitos dos fármacos , Fibroblastos/patologia , Humanos , Hidrogel de Polietilenoglicol-Dimetacrilato/farmacologia , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Masculino , Metaloproteinase 1 da Matriz/metabolismo , Neovascularização Fisiológica/efeitos dos fármacos , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Coelhos , Pele/irrigação sanguínea , Pele/efeitos dos fármacos , Pele/inervação , Linfócitos T/citologia , Alicerces Teciduais/química , Cicatrização/efeitos dos fármacos
14.
Can J Diabetes ; 37(1): 27-35, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24070745

RESUMO

INTRODUCTION: Islet transplantation is a promising strategy to restore efficient insulin regulation in type 1 diabetes mellitus patients. However, shortage of islet donors, poor islet survival and toxicity of immunosuppressants often reduce the graft functional lifetime. METHODS: We previously showed that a fibroblast populated-collagen matrix (CM) significantly improved engrafted islet viability/function. However, this composite was prone to gradual biodegradation and contraction. Moreover, to avoid use of systemic immunosuppressants, we proposed the use of a local immunosuppressive enzyme, indoleamine-2,3-dioxygenase (IDO). We developed a novel bioengineered crosslinked CM (CCM) to provide optimal matrix biomimetic. Viability and insulin secretory function of islets embedded within fibroblast populated CCM (FP-CCM) was evaluated in vitro and in vivo. IDO expression was transduced in fibroblasts by a lentiviral vector carrying IDO gene and islet viability was evaluated in the presence and absence of IDO producing cells. RESULTS: Islet survival/function markedly improved within FP-CCM. Furthermore, our data shows that local lentiviral induction of IDO delivered by FP-CCM is nontoxic to the embedded islets. CONCLUSIONS: This promising finding offers a new approach to improving islet transplant outcome.


Assuntos
Técnicas de Cultura de Células , Ilhotas Pancreáticas/citologia , Animais , Materiais Biomiméticos , Proliferação de Células , Sobrevivência Celular , Colágeno , Indolamina-Pirrol 2,3,-Dioxigenase/genética , Transplante das Ilhotas Pancreáticas/métodos , Masculino , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Alicerces Teciduais
15.
PLoS One ; 8(8): e71044, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23940687

RESUMO

Successful long-term treatment of type-1 diabetes mainly relies on replacement of ß-cells via islet transplantation. Donor shortage is one of the main obstacles preventing transplantation from becoming the treatment of choice. Although animal organs could be an alternative source for transplantation, common immunosuppressive treatments demonstrate low efficacy in preventing xenorejection. Immunoprotective effects of indoleamine 2,3-dioxygenase (IDO) on T-cell mediated allorejection has been extensively studied. Our studies revealed that IDO expression by fibroblasts, induced apoptosis in T-cells while not affecting non-immune cell survival/function. Since macrophages play a pivotal role in xenograft rejection, herein we investigated the effect of IDO-induced tryptophan deficiency/kynurenine accumulation on macrophage function/survival. Moreover, we evaluated the local immunosuppressive effect of IDO on islet-xenograft protection. Our results indicated that IDO expression by bystander fibroblasts significantly reduced the viability of primary macrophages via apoptosis induction. Treatment of peritoneal macrophages by IDO-expressing fibroblast conditioned medium significantly reduced their proinflammatory activity through inhibition of iNOS expression. To determine whether IDO-induced tryptophan starvation or kynurenine accumulation is responsible for macrophage apoptosis and inhibition of their proinflammatory activity, Raw264.7 cell viability and proinflammatory responses were evaluated in tryptophan deficient medium or in the presence of kynurenine. Tryptophan deficiency, but not kynurenine accumulation, reduced Raw264.7 cell viability and suppressed their proinflammatory activity. Next a three-dimensional islet-xenograft was engineered by embedding rat islets within either control or IDO-expressing fibroblast-populated collagen matrix. Islets morphology and immune cell infiltration were then studied in the xenografts transplanted into the C57BL/6 mouse renal sub-capsular space. Local IDO significantly decreased the number of infiltrating macrophages (11 ± 1.47 vs. 70.5 ± 7.57 cells/HPF), T-cells (8.75 ± 1.03 vs. 75.75 ± 5.72 cells/HPF) and iNOS expression in IDO-expressing xenografts versus controls. Islet morphology remained intact in IDO-expressing grafts and islets were strongly stained for insulin/glucagon compared to control. These findings support the immunosuppressive role of IDO on macrophage-mediated xeno-rejection.


Assuntos
Imunidade Inata , Indolamina-Pirrol 2,3,-Dioxigenase/fisiologia , Animais , Apoptose , Linhagem Celular , Proliferação de Células , Sobrevivência Celular , Técnicas de Cocultura , Indução Enzimática , Rejeição de Enxerto/enzimologia , Rejeição de Enxerto/imunologia , Humanos , Interferon gama/farmacologia , Ilhotas Pancreáticas/imunologia , Ilhotas Pancreáticas/metabolismo , Transplante das Ilhotas Pancreáticas/imunologia , Células Jurkat , Cinurenina/metabolismo , Lipopolissacarídeos/farmacologia , Macrófagos Peritoneais/imunologia , Macrófagos Peritoneais/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Ratos , Ratos Long-Evans , Triptofano/deficiência
16.
Mol Cell Biochem ; 372(1-2): 95-100, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23054189

RESUMO

Upon release from keratinocytes, 14-3-3 sigma (also known as stratifin) acts on the dermal fibroblast and modulates its production of extracellular matrix proteins. Subsequent to the recent identification as a receptor responsible for stratifin-mediated matrix turnover in dermal fibroblasts, aminopeptidase N has been implicated in the regulation of epidermal-dermal communication and expression of key matrix proteases and adhesion molecules. In light of the growing importance of aminopeptidase N in modulation of the fibroblast phenotype, the present study evaluates the potential of targeting the ectoenzyme in cutaneous repair, and demonstrates that neutralization of aminopeptidase N led to acceleration of wound closure. This was attributed to at least in part an increase of collagen deposition and fibroblast contractility in the granulation tissue. These findings confirmed the important role of aminopeptidase N in post-injury tissue remodeling and wound contraction.


Assuntos
Anticorpos Neutralizantes/administração & dosagem , Antígenos CD13/antagonistas & inibidores , Pele/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Actinas/metabolismo , Administração Tópica , Animais , Antígenos CD13/imunologia , Antígenos CD13/metabolismo , Células Cultivadas , Colágeno/metabolismo , Ativação Enzimática , Feminino , Humanos , Imidazóis/farmacologia , Sistema de Sinalização das MAP Quinases , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Terapia de Alvo Molecular , Fosforilação , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Piridinas/farmacologia , Pele/metabolismo , Pele/patologia , Pele/fisiopatologia , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
17.
PLoS One ; 7(5): e37747, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22662207

RESUMO

Indoleamine 2,3-dioxygenase (IDO) can locally suppress T cell-mediated immune responses. It has been shown that defective self-tolerance in early prediabetic female non-obese diabetic (NOD) mice can be attributed to the impaired interferon-gamma (IFN-γ)- induced IDO expression in dendritic cells of these animals. As IFN-γ can induce IDO in both dendritic cells and fibroblasts, we asked the question of whether there exists a similar defect in IFN-γ-induced IDO expression in NOD mice dermal fibroblasts. To this end, we examined the effect of IFN-γ on expression of IDO and its enzymatic activity in NOD dermal fibroblasts. The results showed that fibroblasts from either prediabetic (8 wks of age) female or male, and diabetic female or male (12 and 24 wks of age respectively) NOD mice failed to express IDO in response to IFN-γ treatment. To find underlying mechanisms, we scrutinized the IFN- γ signaling pathway and investigated expression of other IFN-γ-modulated factors including major histocompatibility complex class I (MHC-I) and type I collagen (COL-I). The findings revealed a defect of signal transducer and activator of transcription 1 (STAT1) phosphorylation in NOD cells relative to that of controls. Furthermore, we found an increase in MHC-I and suppression of COL-I expression in fibroblasts from both NOD and control mice following IFN-γ treatment; indicating that the impaired response to IFN-γ in NOD fibroblasts is specific to IDO gene. Finally, we showed that an IFN-γ-independent IDO expression pathway i.e. lipopolysaccharide (LPS)-mediated-c-Jun kinase is operative in NOD mice fibroblast. In conclusion, the findings of this study for the first time indicate that IFN-γ fails to induce IDO expression in NOD dermal fibroblasts; this may partially be due to defective STAT1 phosphorylation in IFN-γ-induced-IDO signaling pathway.


Assuntos
Diabetes Mellitus Tipo 1/enzimologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/enzimologia , Indolamina-Pirrol 2,3,-Dioxigenase/genética , Interferon gama/farmacologia , Animais , Colágeno/genética , Células Dendríticas/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Feminino , Fibroblastos/metabolismo , Expressão Gênica/efeitos dos fármacos , Genes MHC Classe I , Lipopolissacarídeos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Fosforilação/efeitos dos fármacos , Fator de Transcrição STAT1/metabolismo , Transdução de Sinais/efeitos dos fármacos , Pele/metabolismo , Baço/metabolismo , Transdução Genética , Triptofano/metabolismo
18.
Mol Cell Biochem ; 360(1-2): 261-70, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21948273

RESUMO

Airway remodelling in asthma involves various mediators modulating the production/breakdown of collagen by lung fibroblasts. Matrix metalloproteinase-1 (MMP-1) plays an important role in collagen breakdown. We recently showed that epithelial cell-derived extracellular form of 14-3-3σ is an important inducer of MMP-1 expression in skin fibroblasts. Thus, we hypothesized that 14-3-3 proteins are important regulators of MMP-1 expression in the respiratory airway. We examined the presence of extracellular 14-3-3 proteins in conditioned media obtained from primary lung epithelial cells, A549 and HS24 cells, and their effect on MMP-1 expression by lung fibroblasts (IMR-90). In addition, we evaluated IMR-90 response to 14-3-3 proteins in the presence of transforming growth factor-ß(1) (TGF-ß(1)), a cytokine known to decrease MMP-1 expression by fibroblasts. Extracellular 14-3-3α/ß, but not -σ, is released by the human-derived lung epithelial cell lines, A549 and HS24. Unlike dermal fibroblasts, IMR-90 cells do not produce MMP-1 in response to 14-3-3σ. Conversely, MMP-1 production was induced following treatment of IMR-90 with recombinant or lung epithelial cell-derived 14-3-3α/ß. These findings were also confirmed using primary human bronchial epithelial cells and lung fibroblasts obtained from non-asthmatic patients. The MMP-1-inducing effect of 14-3-3α/ß on IMR-90 was not inhibited by TGF-ß(1). Lung epithelial cell-derived 14-3-3α/ß has a potent MMP-1-inducing effect on airway fibroblasts. Modulation of MMP-1 by 14-3-3α/ß, may be important in the alteration of collagenase production associated with airway remodelling in obstructive lung diseases. Our data indicate that 14-3-3 proteins may be potential targets for future therapeutic strategies aimed at modulating tissue remodelling in asthma.


Assuntos
Proteínas 14-3-3/fisiologia , Células Epiteliais/metabolismo , Expressão Gênica , Pulmão/patologia , Metaloproteinase 1 da Matriz/metabolismo , Proteínas 14-3-3/metabolismo , Remodelação das Vias Aéreas , Biomarcadores Tumorais/metabolismo , Linhagem Celular Tumoral , Meios de Cultivo Condicionados , Células Epiteliais/enzimologia , Exonucleases/metabolismo , Exorribonucleases , Fibroblastos/enzimologia , Fibroblastos/metabolismo , Regulação da Expressão Gênica , Humanos , Inflamação , L-Lactato Desidrogenase/metabolismo , Metaloproteinase 1 da Matriz/genética , Cultura Primária de Células , Isoformas de Proteínas/metabolismo , Fator de Crescimento Transformador beta1/farmacologia , Fator de Crescimento Transformador beta1/fisiologia
19.
J Cell Physiol ; 226(7): 1813-9, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21506112

RESUMO

Islet transplantation represents a viable treatment for type 1 diabetes. However, due to loss of substantial mass of islets early after transplantation, islets from two or more donors are required to achieve insulin independence. Islet-extracellular matrix disengagement, which occurs during islet isolation process, leads to subsequent islet cell apoptosis and is an important contributing factor to early islet loss. In this study, we developed a fibroblast populated collagen matrix (FPCM) as a novel scaffold to improve islet cell viability and function post-transplantation. FPCM was developed by embedding fibroblasts within type-I collagen and used as scaffold for islet grafts. Viability and insulin secretory function of islets embedded within FPCM was evaluated in vitro and in a syngeneic murine islet transplantation model. Islets embedded within acellular matrix or naked islets were used as control. Islet cell survival and function was markedly improved particularly after embedding within FPCM. The composite scaffold significantly promoted islet isograft survival and reduced the critical islet mass required for diabetes reversal by half (from 200 to 100 islets per recipient). Fibroblast embedded within FPCM produced fibronectin and growth factors and induced islet cell proliferation. No evidence of fibroblast over-growth within composite grafts was noticed. These results confirm that FPCM significantly promotes islet viability and functionality, enhances engraftment of islet grafts and decreases the critical islet mass needed to reverse hyperglycemia. This promising finding offers a new approach to reducing the number of islet donors per recipient and improving islet transplant outcome.


Assuntos
Colágeno Tipo I/metabolismo , Diabetes Mellitus Experimental/cirurgia , Fibroblastos/transplante , Sobrevivência de Enxerto , Transplante das Ilhotas Pancreáticas , Ilhotas Pancreáticas/cirurgia , Alicerces Teciduais , Animais , Apoptose , Glicemia/metabolismo , Proliferação de Células , Células Cultivadas , Técnicas de Cocultura , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Fibroblastos/metabolismo , Fibronectinas/metabolismo , Insulina/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Ilhotas Pancreáticas/metabolismo , Ilhotas Pancreáticas/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fatores de Tempo , Técnicas de Cultura de Tecidos
20.
Inflamm Allergy Drug Targets ; 7(3): 129-35, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18782019

RESUMO

Inflammatory bowel disease (IBD) is a progressive condition in gastrointestinal tract, which refers to two idiopathic diseases; ulcerative colitis and Crohn's disease. Although certain etiology of these conditions is not known, it seems that an abnormality in reaction and regulation of the immune system plays an important role in adventure of the disease. According to the investigations, it is likely that oxidative and nitrosative stress have etiologic roles in IBD. Their destructive effects may contribute to the initiation or progression of the disease. Nowadays, the effectiveness of different medicines in the treatment of IBD has been proved, but none of them has shown a desirable result. Potassium channel openers (PCOs) are a class of drugs with various usages in the aspects of cardiovascular diseases and urinary incontinence. Their major mechanism is the opening of ATP-sensitive potassium (K-ATP) channels and contribute to the relaxation of smooth muscles. Nicorandil is a member of PCOs, with a special chemical structure. Recent investigations mention some novel effects and functions for this drug. Nicorandil reveals an anti-apoptosis property not only via a nitric oxide (NO)/cGMP-dependent mechanism, but also through activating mitochondrial K-ATP channels. Nicorandil can also elevate cGMP levels in some tissues, without direct NO generation. Gastroprotective activity via opening of the K channels, free radical scavenging, prostaglandin E2 elevation, decreasing pepsin and acid secretion, and prevention of the detrimental rise in NO has been proposed for nicorandil. According to these protective mechanisms and the role of oxidative/nitrosative stress in the expression of IBD, we herein hypothesize that nicorandil and other PCOs with similar structure can be used in the management of IBD. This approach offers new hope for the successful treatment of IBD. Further investigations on animal models are needed, to place nicorandil and similar drugs alongside IBD therapy.


Assuntos
Doenças Inflamatórias Intestinais/tratamento farmacológico , Doenças Inflamatórias Intestinais/metabolismo , Nicorandil/uso terapêutico , Canais de Potássio/metabolismo , Animais , Modelos Animais de Doenças , Humanos , Nicorandil/efeitos adversos , Nicorandil/química , Nicorandil/metabolismo , Óxido Nítrico/metabolismo , Estresse Oxidativo
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