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1.
BMJ Open ; 11(11): e053190, 2021 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-34750149

RESUMO

INTRODUCTION: Liver cirrhosis is a growing global healthcare challenge. Cirrhosis is characterised by severe liver fibrosis, organ dysfunction and complications related to portal hypertension. There are no licensed antifibrotic or proregenerative medicines and liver transplantation is a scarce resource. Hepatic macrophages can promote both liver fibrogenesis and fibrosis regression. The safety and feasibility of peripheral infusion of ex vivo matured autologous monocyte-derived macrophages in patients with compensated cirrhosis has been demonstrated. METHODS AND ANALYSIS: The efficacy of autologous macrophage therapy, compared with standard medical care, will be investigated in a cohort of adult patients with compensated cirrhosis in a multicentre, open-label, parallel-group, phase 2, randomised controlled trial. The primary outcome is the change in Model for End-Stage Liver Disease score at 90 days. The trial will provide the first high-quality examination of the efficacy of autologous macrophage therapy in improving liver function, non-invasive fibrosis markers and other clinical outcomes in patients with compensated cirrhosis. ETHICS AND DISSEMINATION: The trial will be conducted according to the ethical principles of the Declaration of Helsinki 2013 and has been approved by Scotland A Research Ethics Committee (reference 15/SS/0121), National Health Service Lothian Research and Development department and the Medicine and Health Care Regulatory Agency-UK. Final results will be presented in peer-reviewed journals and at relevant conferences. TRIAL REGISTRATION NUMBERS: ISRCTN10368050 and EudraCT; reference 2015-000963-15.


Assuntos
Doença Hepática Terminal , Ensaios Clínicos Fase II como Assunto , Humanos , Cirrose Hepática/terapia , Macrófagos , Estudos Multicêntricos como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto , Pesquisa , Índice de Gravidade de Doença , Medicina Estatal , Resultado do Tratamento
2.
Cytotherapy ; 22(12): 762-771, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32828673

RESUMO

BACKGROUND AIMS: Mesenchymal stromal cells (MSCs) isolated from various tissues are under investigation as cellular therapeutics in a wide range of diseases. It is appreciated that the basic biological functions of MSCs vary depending on tissue source. However, in-depth comparative analyses between MSCs isolated from different tissue sources under Good Manufacturing Practice (GMP) conditions are lacking. Human clinical-grade low-purity islet (LPI) fractions are generated as a byproduct of islet isolation for transplantation. MSC isolates were derived from LPI fractions with the aim of performing a systematic, standardized comparative analysis of these cells with clinically relevant bone marrow-derived MSCs (BM MSCs). METHODS: MSC isolates were derived from LPI fractions and expanded in platelet lysate-supplemented medium or in commercially available xenogeneic-free medium. Doubling rate, phenotype, differentiation potential, gene expression, protein production and immunomodulatory capacity of LPIs were compared with those of BM MSCs. RESULTS: MSCs can be readily derived in vitro from non-transplanted fractions resulting from islet cell processing (i.e., LPI MSCs). LPI MSCs grow stably in serum-free or platelet lysate-supplemented media and demonstrate in vitro self-renewal, as measured by colony-forming unit assay. LPI MSCs express patterns of chemokines and pro-regenerative factors similar to those of BM MSCs and, importantly, are equally able to attract immune cells in vitro and in vivo and suppress T-cell proliferation in vitro. Additionally, LPI MSCs can be expanded to therapeutically relevant doses at low passage under GMP conditions. CONCLUSIONS: LPI MSCs represent an alternative source of GMP MSCs with functions comparable to BM MSCs.


Assuntos
Células da Medula Óssea/citologia , Técnicas de Cultura de Células/métodos , Imunidade , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/imunologia , Neovascularização Fisiológica , Pâncreas/citologia , Biomarcadores/metabolismo , Diferenciação Celular , Proliferação de Células , Forma Celular , Células Cultivadas , Ensaio de Unidades Formadoras de Colônias , Humanos , Imunomodulação , Interferon gama/metabolismo , Medicina Regenerativa , Linfócitos T/citologia
3.
Sci Transl Med ; 12(526)2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31941825

RESUMO

Islet transplantation is an efficacious therapy for type 1 diabetes; however, islets from multiple donor pancreata are required, and a gradual attrition in transplant function is seen. Here, we manufactured human umbilical cord perivascular mesenchymal stromal cells (HUCPVCs) to Good Manufacturing Practice (GMP) standards. HUCPVCs showed a stable phenotype while undergoing rapid ex vivo expansion at passage 2 (p2) to passage 4 (p4) and produced proregenerative factors, strongly suppressing T cell responses in the resting state and in response to inflammation. Transplanting an islet equivalent (IEQ):HUCPVC ratio of 1:30 under the kidney capsule in diabetic NSG mice demonstrated the fastest return to normoglycemia by 3 days after transplant: Superior glycemic control was seen at both early (2.7 weeks) and later stages (7, 12, and 16 weeks) versus ratios of 1:0, 1:10, and 1:50, respectively. Syngeneic islet transplantation in immunocompetent mice using the clinically relevant hepatic portal route with a marginal islet mass showed that mice transplanted with an IEQ:HUCPVC ratio of 1:150 had superior glycemic control versus ratios of 1:0, 1:90, and 1:210 up to 6 weeks after transplant. Immunodeficient mice transplanted with human islets (IEQ:HUCPVC ratio of 1:150) exhibited better glycemic control for 7 weeks after transplant versus islet transplant alone, and islets transplanted via the hepatic portal vein in an allogeneic mouse model using a curative islet mass demonstrated delayed rejection of islets when cotransplanted with HUCPVCs (IEQ:HUCPVC ratio of 1:150). The immunosuppressive and proregenerative properties of HUCPVCs demonstrated long-term positive effects on graft function in vivo, indicating that they may improve long-term human islet allotransplantation outcomes.


Assuntos
Transplante das Ilhotas Pancreáticas/métodos , Cordão Umbilical/citologia , Animais , Glicemia/metabolismo , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/cirurgia , Humanos , Ilhotas Pancreáticas/metabolismo , Camundongos , Veia Porta/metabolismo
4.
ACR Open Rheumatol ; 1(6): 382-393, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31777818

RESUMO

OBJECTIVE: The association between inflammation and dysregulated bone remodeling is apparent in rheumatoid arthritis and is recapitulated in the human tumor necrosis factor transgenic (hTNFtg) mouse model. We investigated whether extracellular binding immunoglobulin protein (BiP) would protect the hTNFtg mouse from both inflammatory arthritis as well as extensive systemic bone loss and whether BiP had direct antiosteoclast properties in vitro. METHODS: hTNFtg mice received a single intraperitoneal administration of BiP at onset of arthritis. Clinical disease parameters were measured weekly. Bone analysis was performed by microcomputed tomography and histomorphometry. Mouse bone marrow macrophage and human peripheral blood monocyte precursors were used to study the direct effect of BiP on osteoclast differentiation and function in vitro. Monocyte and osteoclast signaling was analyzed by Western blotting, flow cytometry, and imaging flow cytometry. RESULTS: BiP-treated mice showed reduced inflammation and cartilage destruction, and histomorphometric analysis revealed a decrease in osteoclast number with protection from systemic bone loss. Abrogation of osteoclast function was also observed in an ex vivo murine calvarial model. BiP inhibited differentiation of osteoclast precursors and prevented bone resorption by mature osteoclasts in vitro. BiP also induced downregulation of CD115/c-Fms and Receptor Activator of NF-κB (RANK) messenger RNA and protein, causing reduced phosphorylation of the p38 mitogen-activated protein kinases, extracellular signal-regulated kinases 1/2 and p38, with suppression of essential osteoclast transcription factors, c-Fos and NFATc1. BiP directly inhibited TNF-α- or Receptor Activator of NF-κB Ligand (RANKL)-induced NF-κB nuclear translocation in THP-1 monocytic cells and preosteoclasts by the canonical and noncanonical pathways. CONCLUSION: BiP combines an anti-inflammatory function with antiosteoclast activity, which establishes it as a potential novel therapeutic for inflammatory disorders associated with bone loss.

5.
Nat Med ; 25(10): 1560-1565, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31591593

RESUMO

Therapies to reduce liver fibrosis and stimulate organ regeneration are urgently needed. We conducted a first-in-human, phase 1 dose-escalation trial of autologous macrophage therapy in nine adults with cirrhosis and a Model for End-Stage Liver Disease (MELD) score of 10-16 (ISRCTN 10368050). Groups of three participants received a single peripheral infusion of 107, 108 or up to 109 cells. Leukapheresis and macrophage infusion were well tolerated with no transfusion reactions, dose-limiting toxicities or macrophage activation syndrome. All participants were alive and transplant-free at one year, with only one clinical event recorded, the occurrence of minimal ascites. The primary outcomes of safety and feasibility were met. This study informs and provides a rationale for efficacy studies in cirrhosis and other fibrotic diseases.


Assuntos
Terapia Baseada em Transplante de Células e Tecidos/métodos , Doença Hepática Terminal/terapia , Cirrose Hepática/terapia , Macrófagos/transplante , Idoso , Terapia Baseada em Transplante de Células e Tecidos/efeitos adversos , Relação Dose-Resposta Imunológica , Doença Hepática Terminal/imunologia , Doença Hepática Terminal/patologia , Feminino , Humanos , Fígado/metabolismo , Fígado/patologia , Cirrose Hepática/imunologia , Cirrose Hepática/patologia , Regeneração Hepática , Macrófagos/imunologia , Masculino , Pessoa de Meia-Idade
6.
Stem Cells Transl Med ; 8(4): 323-331, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30688407

RESUMO

Limbal stem cell deficiency (LSCD) is a disease resulting from the loss or dysfunction of epithelial stem cells, which seriously impairs sight. Autologous limbal stem cell transplantation is effective in unilateral or partial bilateral disease but not applicable in total bilateral disease. An allogeneic source of transplantable cells for use in total bilateral disease can be obtained from culture of donated cadaveric corneal tissue. We performed a controlled multicenter study to examine the feasibility, safety, and efficacy of allogeneic corneal epithelial stem cells in the treatment of bilateral LSCD. Patients were randomized to receive corneal epithelial stem cells cultured on amniotic membrane (AM): investigational medicinal product (IMP) or control AM only. Patients received systemic immunosuppression. Primary endpoints were safety and visual acuity, secondary endpoint was change in composite ocular surface score (OSS). Sixteen patients were treated and 13 patients completed all assessments. Safety was demonstrated and 9/13 patients had improved visual acuity scores at the end of the trial, with no significant differences between IMP and control groups. Patients in the IMP arm demonstrated significant, sustained improvement in OSS, whereas those in the control arm did not. Serum cytokine levels were measured during and after the period of immune suppression and we identified strongly elevated levels of CXCL8 in the serum of patients with aniridia, which persisted throughout the trial. This first randomized control trial of allogeneic corneal epithelial stem cells in severe bilateral LSCD demonstrates the feasibility and safety of this approach. Stem Cells Translational Medicine 2019;8:323-331.


Assuntos
Córnea/citologia , Córnea/cirurgia , Células Epiteliais/citologia , Epitélio Corneano/citologia , Células-Tronco/citologia , Adulto , Idoso , Âmnio/citologia , Âmnio/cirurgia , Doenças da Córnea/cirurgia , Transplante de Córnea/métodos , Feminino , Transplante de Células-Tronco Hematopoéticas/métodos , Humanos , Limbo da Córnea/citologia , Limbo da Córnea/cirurgia , Masculino , Pessoa de Meia-Idade , Método Simples-Cego , Transplante de Células-Tronco/métodos , Transplante Autólogo/métodos , Acuidade Visual/fisiologia , Adulto Jovem
7.
Methods Mol Biol ; 1698: 285-292, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29076098

RESUMO

Blood transfusion is a mainstay of modern medical practice. In many parts of the world the use of this life-saving therapy is hampered by issues of supply and the potential for transfusion transmitted infections. Accordingly, there are many studies seeking to find an alternative to donated red blood cells (RBCs) for transfusion, including large-scale production from adult and pluripotent stem cells, or erythroid cell lines. Translating basic studies, using any cell lineage, into protocols that are suitable for the generation of cellular therapies requires a wide range of biological and regulatory procedures to be put in place. Additionally, there are specific challenges for the production of RBCs caused by the number of cells needed for a single dose (approx. 1-2 × 1012). In this chapter, we will review critical areas in the development and good manufacturing practice (GMP) translation of cellular therapeutics through to early phase clinical trials and how this learning can be applied to in vitro RBC therapies.


Assuntos
Terapia Baseada em Transplante de Células e Tecidos/normas , Guias como Assunto , Animais , Biotecnologia , Terapia Baseada em Transplante de Células e Tecidos/efeitos adversos , Terapia Baseada em Transplante de Células e Tecidos/métodos , Ensaios Clínicos como Assunto , Eritrócitos/citologia , Eritrócitos/metabolismo , Humanos , Técnicas In Vitro , Farmacovigilância , Pesquisa , Pesquisa Translacional Biomédica/métodos , Pesquisa Translacional Biomédica/normas
8.
PLoS One ; 11(5): e0156204, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27243814

RESUMO

Transcription factor mediated lineage reprogramming of human pancreatic exocrine tissue could conceivably provide an unlimited supply of islets for transplantation in the treatment of diabetes. Exocrine tissue can be efficiently reprogrammed to islet-like cells using a cocktail of transcription factors: Pdx1, Ngn3, MafA and Pax4 in combination with growth factors. We show here that overexpression of exogenous Pax4 in combination with suppression of the endogenous transcription factor ARX considerably enhances the production of functional insulin-secreting ß-like cells with concomitant suppression of α-cells. The efficiency was further increased by culture on laminin-coated plates in media containing low glucose concentrations. Immunocytochemistry revealed that reprogrammed cultures were composed of ~45% islet-like clusters comprising >80% monohormonal insulin+ cells. The resultant ß-like cells expressed insulin protein levels at ~15-30% of that in adult human islets, efficiently processed proinsulin and packaged insulin into secretory granules, exhibited glucose responsive insulin secretion, and had an immediate and prolonged effect in normalising blood glucose levels upon transplantation into diabetic mice. We estimate that approximately 3 billion of these cells would have an immediate therapeutic effect following engraftment in type 1 diabetes patients and that one pancreas would provide sufficient tissue for numerous transplants.


Assuntos
Terapia Baseada em Transplante de Células e Tecidos/métodos , Técnicas de Reprogramação Celular/métodos , Diabetes Mellitus Experimental/terapia , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Células Secretoras de Insulina/transplante , Fatores de Transcrição Box Pareados/metabolismo , Pâncreas Exócrino/citologia , Fatores de Transcrição/genética , Adulto , Animais , Células Cultivadas , Feminino , Glucose/metabolismo , Humanos , Insulina/metabolismo , Células Secretoras de Insulina/citologia , Células Secretoras de Insulina/metabolismo , Masculino , Camundongos , Camundongos SCID , Pâncreas Exócrino/metabolismo , Proinsulina/metabolismo , Interferência de RNA , RNA Interferente Pequeno/genética , Estreptozocina , Adulto Jovem
9.
PLoS One ; 10(10): e0140352, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26457418

RESUMO

A replenishable source of insulin-producing cells has the potential to cure type 1 diabetes. Attempts to culture and expand pancreatic ß-cells in vitro have resulted in their transition from insulin-producing epithelial cells to mesenchymal stromal cells (MSCs) with high proliferative capacity but devoid of any hormone production. The aim of this study was to determine whether the transcription factor Krüppel-like factor 4 (KLF4), could induce a mesenchymal-to-epithelial transition (MET) of the cultured cells. Islet-enriched pancreatic cells, allowed to dedifferentiate and expand in adherent cell culture, were transduced with an adenovirus containing KLF4 (Ad-Klf4). Cells were subsequently analysed for changes in cell morphology by light microscopy, and for the presence of epithelial and pancreatic markers by immunocytochemistry and quantitative RT/PCR. Infection with Ad-Klf4 resulted in morphological changes, down-regulation of mesenchymal markers, and re-expression of both epithelial and pancreatic cell markers including insulin and transcription factors specific to ß-cells. This effect was further enhanced by culturing cells in suspension. However, the effects of Ad-KLf4 were transient and this was shown to be due to increased apoptosis in Klf4-expressing cells. Klf4 has been recently identified as a pioneer factor with the ability to modulate the structure of chromatin and enhance reprogramming/transdifferentiation. Our results show that Klf4 may have a role in the redifferentiation of expanded pancreatic cells in culture, but before this can be achieved the off-target effects that result in increased apoptosis would need to be overcome.


Assuntos
Transdiferenciação Celular/genética , Transição Epitelial-Mesenquimal/genética , Expressão Gênica , Fatores de Transcrição Kruppel-Like/genética , Pâncreas/citologia , Pâncreas/metabolismo , Adipogenia/genética , Biomarcadores , Comunicação Celular/genética , Técnicas de Cultura de Células , Diferenciação Celular/genética , Linhagem da Célula/genética , Células Cultivadas , Humanos , Células Secretoras de Insulina/citologia , Células Secretoras de Insulina/metabolismo , Ilhotas Pancreáticas/citologia , Ilhotas Pancreáticas/metabolismo , Fator 4 Semelhante a Kruppel , Fatores de Transcrição Kruppel-Like/metabolismo , Osteogênese/genética
10.
Cytotherapy ; 17(11): 1604-16, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26342993

RESUMO

BACKGROUND AIMS: Macrophages have complex roles in the liver. The aim of this study was to compare profiles of human monocyte-derived macrophages between controls and cirrhotic patients, to determine whether chronic inflammation affects precursor number or the phenotype, with the eventual aim to develop a cell therapy for cirrhosis. METHODS: Infusion of human macrophages in a murine liver fibrosis model demonstrated a decrease in markers of liver injury (alanine transaminase, bilirubin, aspartate transaminase) and fibrosis (transforming growth factor-ß, α-smooth muscle actin, phosphatidylserine receptor) and an increase in markers of liver regeneration (matrix metalloproteinases [MMP]-9, MMP-12 and TNF-related weak inducer of apoptosis). CD14+ monocytes were then isolated from controls. Monocytes were matured into macrophages for 7 days using a Good Manufacturing Practice-compatible technique. RESULTS: There was no significant difference between the mean number of CD14+ monocytes isolated from cirrhotic patients (n = 9) and controls (n = 10); 2.8 ± SEM 0.54 × 10(8) and 2.5 ± 0.56 × 10(8), respectively. The mean yield of mature macrophages cultured was also not significantly different between cirrhotic patients and controls (0.9 × 10(8) ± 0.38 × 10(8), with more than 90% viability and 0.65 × 10(8) ± 0.16 × 10(8), respectively. Maturation to macrophages resulted in up-regulation of a number of genes (MMP-9, CCL2, interleukin [IL]-10 and TNF-related weak inducer of apoptosis). A cytokine and chemokine polymerase chain reaction array, comparing the control and cirrhotic macrophages, revealed no statistically significant differences. CONCLUSIONS: Macrophages can be differentiated from cirrhotic patients' apheresis-derived CD14 monocytes and develop the same pro-resolution phenotype as control macrophages, indicating their suitability for clinical therapy.


Assuntos
Cirrose Hepática/patologia , Macrófagos/fisiologia , Idoso , Animais , Estudos de Casos e Controles , Diferenciação Celular/imunologia , Diferenciação Celular/fisiologia , Células Cultivadas , Quimiocinas/genética , Estudos de Coortes , Citocinas/genética , Modelos Animais de Doenças , Feminino , Humanos , Receptores de Lipopolissacarídeos/metabolismo , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/terapia , Regeneração Hepática , Macrófagos/metabolismo , Masculino , Camundongos Endogâmicos NOD , Pessoa de Meia-Idade , Monócitos/citologia , Monócitos/patologia
11.
Diabetologia ; 58(6): 1300-8, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25810037

RESUMO

AIMS/HYPOTHESIS: Type 1 diabetes complicated by hypoglycaemia is prevalent in socioeconomically deprived populations. Islet transplantation is of proven efficacy in type 1 diabetes complicated by hypoglycaemia, but it is not known if nationally funded programmes reach the socioeconomically deprived. Our aim was to determine: (1) socioeconomic indices in participants referred to our nationally funded programme; and (2) if metabolic outcomes in our transplant recipients were improved. METHODS: Participants referred (n = 106) and receiving transplants (n = 18; 32 infusions) were examined with respect to socioeconomic status (deprivation category score) and their ability to work and drive. In participants followed for ≥12 months after transplantation, metabolic and anthropometric measurements (n = 14) were recorded pre- and post-transplant (assessed ~1, ~3, ~6 and ~12 months with mixed-meal tolerance tests and 6 day continuous glucose monitoring assessments). Donor data was also examined. RESULTS: There was a greater prevalence of socioeconomic deprivation in referred and transplant recipients than the general population (p < 0.05). Of the transplant recipients, 73% were socioeconomically deprived, 88% did not hold a driver's license and 94% had reduced ability to work (all p < 0.01 vs referred participants). Donors were predominantly obese and included circulatory death donors. At 12 months, 93% of participants who had received transplants had graft function, diminished frequency of hypoglycaemia (10 [4-11] vs 0 [0-2] hypoglycaemic episodes/week), improved awareness of hypoglycaemia (Gold score 7 [5-7] vs 1 [1-2]) and glycaemic control (HbA1c: 7.9% [7.2-8.5%]; 63 [55-69] mmol/mol vs 7.2% [6.8-7.5%]; 55 [51-58] mmol/mol), diminished glycaemic lability and decreased central adiposity (all p < 0.05). CONCLUSIONS/INTERPRETATION: A nationally funded islet transplant programme reaches the socioeconomically deprived and outcomes are significantly improved in this group.


Assuntos
Diabetes Mellitus Tipo 1/epidemiologia , Diabetes Mellitus Tipo 1/terapia , Transplante das Ilhotas Pancreáticas/métodos , Adiposidade , Adulto , Antropometria , Condução de Veículo , Glicemia/análise , Diabetes Mellitus Tipo 1/complicações , Feminino , Financiamento Governamental , Acessibilidade aos Serviços de Saúde , Humanos , Hipoglicemia/complicações , Hipoglicemia/epidemiologia , Hipoglicemia/terapia , Transplante das Ilhotas Pancreáticas/economia , Masculino , Pessoa de Meia-Idade , Classe Social , Doadores de Tecidos , Transplantados , Reino Unido , Adulto Jovem
12.
Diabetes ; 62(8): 2821-33, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23610058

RESUMO

Because of the lack of tissue available for islet transplantation, new sources of ß-cells have been sought for the treatment of type 1 diabetes. The aim of this study was to determine whether the human exocrine-enriched fraction from the islet isolation procedure could be reprogrammed to provide additional islet tissue for transplantation. The exocrine-enriched cells rapidly dedifferentiated in culture and grew as a mesenchymal monolayer. Genetic lineage tracing confirmed that these mesenchymal cells arose, in part, through a process of epithelial-to-mesenchymal transitioning (EMT). A protocol was developed whereby transduction of these mesenchymal cells with adenoviruses containing Pdx1, Ngn3, MafA, and Pax4 generated a population of cells that were enriched in glucagon-secreting α-like cells. Transdifferentiation or reprogramming toward insulin-secreting ß-cells was enhanced, however, when using unpassaged cells in combination with inhibition of EMT by inclusion of Rho-associated kinase (ROCK) and transforming growth factor-ß1 inhibitors. Resultant cells were able to secrete insulin in response to glucose and on transplantation were able to normalize blood glucose levels in streptozotocin diabetic NOD/SCID mice. In conclusion, reprogramming of human exocrine-enriched tissue can be best achieved using fresh material under conditions whereby EMT is inhibited, rather than allowing the culture to expand as a mesenchymal monolayer.


Assuntos
Diferenciação Celular/fisiologia , Transição Epitelial-Mesenquimal/fisiologia , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Pâncreas Exócrino/metabolismo , Animais , Células Cultivadas , Diabetes Mellitus Experimental/metabolismo , Glucose/farmacologia , Humanos , Secreção de Insulina , Células Secretoras de Insulina/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Pâncreas Exócrino/efeitos dos fármacos , Quinases Associadas a rho/metabolismo
13.
Proc Natl Acad Sci U S A ; 107(29): 12913-8, 2010 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-20616007

RESUMO

The neighbor of Brca1 gene (Nbr1) functions as an autophagy receptor involved in targeting ubiquitinated proteins for degradation. It also has a dual role as a scaffold protein to regulate growth-factor receptor and downstream signaling pathways. We show that genetic truncation of murine Nbr1 leads to an age-dependent increase in bone mass and bone mineral density through increased osteoblast differentiation and activity. At 6 mo of age, despite normal body size, homozygous mutant animals (Nbr1(tr/tr)) have approximately 50% more bone than littermate controls. Truncated Nbr1 (trNbr1) co-localizes with p62, a structurally similar interacting scaffold protein, and the autophagosome marker LC3 in osteoblasts, but unlike the full-length protein, trNbr1 fails to complex with activated p38 MAPK. Nbr1(tr/tr) osteoblasts and osteoclasts show increased activation of p38 MAPK, and significantly, pharmacological inhibition of the p38 MAPK pathway in vitro abrogates the increased osteoblast differentiation of Nbr1(tr/tr) cells. Nbr1 truncation also leads to increased p62 protein expression. We show a role for Nbr1 in bone remodeling, where loss of function leads to perturbation of p62 levels and hyperactivation of p38 MAPK that favors osteoblastogenesis.


Assuntos
Osteoblastos/enzimologia , Osteogênese , Proteínas/genética , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Animais Recém-Nascidos , Densidade Óssea , Células COS , Diferenciação Celular , Chlorocebus aethiops , Vesículas Citoplasmáticas/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular , Camundongos , Camundongos Mutantes , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Mutantes/metabolismo , Tamanho do Órgão , Osteoblastos/citologia , Estabilidade Proteica , Transporte Proteico , Proteínas/metabolismo , Frações Subcelulares/metabolismo , Fator de Transcrição TFIIH , Fatores de Transcrição/metabolismo
14.
J Clin Endocrinol Metab ; 88(7): 3321-6, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12843182

RESUMO

Camurati-Engelmann disease (CED) is a rare autosomal dominant disorder characterized by bone pain and osteosclerosis affecting the diaphysis of long bones. CED is caused by various missense mutations in the TGFB1 gene that encodes TGFbeta1, the most common of which is an arginine-cysteine amino acid change at codon 218 (R218C) in the latency-associated peptide domain of TGFbeta1. We studied osteoclast formation in vitro from peripheral blood mononuclear cells obtained from three related CED patients harboring the R218C mutation, in comparison with one family-based and several unrelated controls. Osteoclast formation was enhanced approximately 5-fold (P < 0.001) and bone resorption approximately 10-fold (P < 0.001) in CED patients, and the increase in osteoclast formation was inhibited by soluble TGFbeta type II receptor. Total serum TGFbeta1 levels were similar in affected and unaffected subjects, but concentrations of active TGFbeta1 in conditioned medium of osteoclast cultures was higher in the three CED patients than in the unaffected family member. We concluded that the R218C mutation increases TGFbeta1 bioactivity and enhances osteoclast formation in vitro. The activation of osteoclast activity noted here is consistent with clinical reports that have shown biochemical evidence of increased bone resorption as well as bone formation in CED.


Assuntos
Síndrome de Camurati-Engelmann/genética , Síndrome de Camurati-Engelmann/fisiopatologia , Osteoclastos/citologia , Mutação Puntual , Fator de Crescimento Transformador beta/genética , Adulto , Idoso , Anticorpos/farmacologia , Síndrome de Camurati-Engelmann/diagnóstico por imagem , Proteínas de Transporte/farmacologia , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Feminino , Humanos , Técnicas In Vitro , Leucócitos Mononucleares/citologia , Fator Estimulador de Colônias de Macrófagos/farmacologia , Masculino , Glicoproteínas de Membrana/farmacologia , Ligante RANK , Radiografia , Receptor Ativador de Fator Nuclear kappa-B , Fator de Crescimento Transformador beta/imunologia , Fator de Crescimento Transformador beta1
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