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1.
Khirurgiia (Mosk) ; (5): 12-19, 2020.
Artigo em Russo | MEDLINE | ID: mdl-32500684

RESUMO

OBJECTIVE: To compare different clinical and morphometric features of patients undergoing TPAIT for prediction of postoperative outcomes. MATERIAL AND METHODS: A retrospective review enrolled patients who underwent TPAIT for the period from January 2007 to October 2017. Morphometric parameters were analyzed using preoperative CT scans and patients were grouped to examine association of these characteristics with postoperative morbidity. Sarcopenia was defined as the presence of a TPA in the lowest sex-specific quartile. The impact of sarcopenia on pancreatic islet features, perioperative blood transfusion, ICU- and hospital-stay, complications, repeated admission within 90 days and islet function was assessed. RESULTS: A total of 34 patients were included in this study (12 males and 24 females). At the time of diagnosis, mean age of patients was 43.1 years. Mean body mass index (BMI) in sarcopenic patients was 24.9 kg/m2, mean BMI in those without sarcopenia - 24.8 kg/m2 (p=1.00). Various surgical complications were observed in 11 patients (32.3%). Patients with sarcopenia experienced more complications (83.3%) compared with patients without sarcopenia (50%). However, differences were not significant (p=0.31). Islet characteristics (islet numbers, purity), readmission, ICU- and hospital-stay, incidence of blood transfusion and islet function were also similar in both groups. CONCLUSION: Sarcopenia is not a predictor of postoperative complications and islet cell function in chronic pancreatitis patients following TPAIT.


Assuntos
Transplante das Ilhotas Pancreáticas , Pancreatectomia , Pancreatite Crônica/cirurgia , Sarcopenia/fisiopatologia , Tecido Adiposo/fisiopatologia , Adulto , Feminino , Humanos , Masculino , Pancreatite Crônica/complicações , Pancreatite Crônica/fisiopatologia , Estudos Retrospectivos , Sarcopenia/complicações , Transplante Autólogo , Resultado do Tratamento
2.
Cell Prolif ; 53(5): e12785, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32339373

RESUMO

Regenerative medicine using human or porcine ß-cells or islets has an excellent potential to become a clinically relevant method for the treatment of type-1 diabetes. High-resolution imaging of the function and faith of transplanted porcine pancreatic islets and human stem cell-derived beta cells in large animals and patients for testing advanced therapy medicinal products (ATMPs) is a currently unmet need for pre-clinical/clinical trials. The iNanoBIT EU H2020 project is developing novel highly sensitive nanotechnology-based imaging approaches allowing for monitoring of survival, engraftment, proliferation, function and whole-body distribution of the cellular transplants in a porcine diabetes model with excellent translational potential to humans. We develop and validate the application of single-photon emission computed tomography (SPECT) and optoacoustic imaging technologies in a transgenic insulin-deficient pig model to observe transplanted porcine xeno-islets and in vitro differentiated human beta cells. We are progressing in generating new transgenic reporter pigs and human-induced pluripotent cell (iPSC) lines for optoacoustic imaging and testing them in transplantable bioartificial islet devices. Novel multifunctional nanoparticles have been generated and are being tested for nuclear imaging of islets and beta cells using a new, high-resolution SPECT imaging device. Overall, the combined multidisciplinary expertise of the project partners allows progress towards creating much needed technological toolboxes for the xenotransplantation and ATMP field, and thus reinforces the European healthcare supply chain for regenerative medicinal products.


Assuntos
Biotecnologia/métodos , Diabetes Mellitus Tipo 1/terapia , Transplante das Ilhotas Pancreáticas/métodos , Ilhotas Pancreáticas/cirurgia , Nanotecnologia/métodos , Animais , Animais Geneticamente Modificados , Humanos , Medicina Regenerativa/métodos , Suínos
3.
Int J Nanomedicine ; 15: 587-599, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32095072

RESUMO

Introduction: As heterologous islets or islet-like stem cells become optional sources for islet transplantation, the subcutaneous site appears to be an acceptable replacement of the intrahepatic site due to its graft retrievability. The device-less (DL) procedure improves the feasibility; however, some limitations such as fibrotic overgrowth or immunodeficiency still exist. Nanofibers could mimic the extracellular matrix to improve the vitality of transplanted islets. Therefore, we designed a vascular endothelial growth factor (VEGF)-modified polyvinyl alcohol (PVA)/silicone nanofiber (SiO2-VEGF) to optimize the DL procedure. Methods: SiO2-VEGF nanofibers were designed by nano-spinning and characterized the physical-chemical properties before subcutaneous islet transplantation. Cell viability, vessel formation, and glucose-stimulated insulin secretion were tested in vitro to ensure biocompatibility; and blood glucose level (BGL), transplanted islet function, and epithelial-mesenchymal transition (EMT)-related biomarker expression were analyzed in vivo. Results: The intensity of inflammatory reaction induced by SiO2 nanofibers was between nylon and silicone, which did not bring out excessive fibrosis. The vascularization could be enhanced by VEGF functionalization both in vitro and in vivo. The BGL control was better in the DL combined with SiO2-VEGF group. The percentage of recipients that achieved normoglycemia was higher and earlier (71% at day 57), and the intraperitoneal glucose tolerance test (IPGTT) also confirmed better islet function. The expressions of vimentin, α-SMA, and twist-1 were upregulated, which indicated that SiO2-VEGF nanofibers might promote islet function by regulating the EMT pathway. Discussion: In summary, our new SiO2-VEGF combined with DL procedure might improve the feasibility of subcutaneous islet transplantation for clinical application.


Assuntos
Diabetes Mellitus Experimental/terapia , Transplante das Ilhotas Pancreáticas/métodos , Nanofibras/química , Fator A de Crescimento do Endotélio Vascular/farmacologia , Animais , Glicemia/análise , Glicemia/metabolismo , Diabetes Mellitus Experimental/sangue , Células Endoteliais da Veia Umbilical Humana , Humanos , Injeções Subcutâneas , Insulina/metabolismo , Transplante das Ilhotas Pancreáticas/efeitos adversos , Transplante das Ilhotas Pancreáticas/instrumentação , Masculino , Camundongos Endogâmicos ICR , Neovascularização Fisiológica/efeitos dos fármacos , Álcool de Polivinil/química , Dióxido de Silício/química , Silicones/química , Fator A de Crescimento do Endotélio Vascular/química
4.
FASEB J ; 34(1): 945-959, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31914664

RESUMO

The dynamics of cytoplasmic free Ca2+ concentration ([Ca2+]i) in pancreatic ß cells is central to our understanding of ß-cell physiology and pathology. In this context, there are numerous in vitro studies available but existing in vivo data are scarce. We now critically evaluate the anterior chamber of the eye as an in vivo, non-invasive, imaging site for measuring [Ca2+]i dynamics longitudinally in three dimensions and at single-cell resolution. By applying a fluorescently labeled glucose analogue 2-(N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)Amino)-2-Deoxyglucose in vivo, we followed how glucose almost simultaneously distributes to all cells within the islet volume, resulting in [Ca2+]i changes. We found that almost all ß cells in healthy mice responded to a glucose challenge, while in hyperinsulinemic, hyperglycemic mice about 80% of the ß cells could not be further stimulated from fasting basal conditions. This finding indicates that our imaging modality can resolve functional heterogeneity within the ß-cell population in terms of glucose responsiveness. Importantly, we demonstrate that glucose homeostasis is markedly affected using isoflurane compared to hypnorm/midazolam anesthetics, which has major implications for [Ca2+]i measurements. In summary, this setup offers a powerful tool to further investigate in vivo pancreatic ß-cell [Ca2+]i response patterns at single-cell resolution in health and disease.


Assuntos
Cálcio/química , Células Secretoras de Insulina/metabolismo , Anestésicos/farmacologia , Animais , Câmara Anterior/cirurgia , Cálcio/metabolismo , Cruzamentos Genéticos , Feminino , Glucose/farmacologia , Teste de Tolerância a Glucose , Heterozigoto , Homeostase , Hiperglicemia/metabolismo , Hiperinsulinismo/metabolismo , Ilhotas Pancreáticas/citologia , Transplante das Ilhotas Pancreáticas , Isoflurano/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Midazolam/farmacologia , Fenótipo
5.
FASEB J ; 34(1): 1901-1911, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31914605

RESUMO

Human pancreatic islets engrafted into immunodeficient mice serve as an important model for in vivo human diabetes studies. Following engraftment, islet function can be monitored in vivo by measuring circulating glucose and human insulin; however, it will be important to recover viable cells for more complex graft analyses. Moreover, RNA analyses of dissected grafts have not distinguished which hormone-specific cell types contribute to gene expression. We developed a method for recovering live cells suitable for fluorescence-activated cell sorting from human islets engrafted in mice. Although yields of recovered islet cells were relatively low, the ratios of bulk-sorted ß, α, and δ cells and their respective hormone-specific RNA-Seq transcriptomes are comparable pretransplant and posttransplant, suggesting that the cellular characteristics of islet grafts posttransplant closely mirror the original donor islets. Single-cell RNA-Seq transcriptome analysis confirms the presence of appropriate ß, α, and δ cell subsets. In addition, ex vivo perifusion of recovered human islet grafts demonstrated glucose-stimulated insulin secretion. Viable cells suitable for patch-clamp analysis were recovered from transplanted human embryonic stem cell-derived ß cells. Together, our functional and hormone-specific transcriptome analyses document the broad applicability of this system for longitudinal examination of human islet cells undergoing developmental/metabolic/pharmacogenetic manipulation in vivo and may facilitate the discovery of treatments for diabetes.


Assuntos
Células Endócrinas/fisiologia , Ilhotas Pancreáticas/fisiologia , Transcriptoma/fisiologia , Adulto , Animais , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Células Endócrinas/metabolismo , Feminino , Perfilação da Expressão Gênica/métodos , Sobrevivência de Enxerto/fisiologia , Humanos , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/fisiologia , Ilhotas Pancreáticas/metabolismo , Transplante das Ilhotas Pancreáticas/métodos , Masculino , Camundongos , Transplante Heterólogo/métodos , Adulto Jovem
6.
Sci Rep ; 10(1): 1190, 2020 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-31988329

RESUMO

Pluripotent stem cell (PSC)-derived insulin-producing cells are a promising cell source for diabetes cellular therapy. However, the efficiency of the multi-step process required to differentiate PSCs towards pancreatic beta cells is variable between cell lines, batches and even within cultures. In adherent pancreatic differentiation protocols, we observed spontaneous local clustering of cells expressing elevated nuclear expression of pancreatic endocrine transcription factors, PDX1 and NKX6.1. Since aggregation has previously been shown to promote downstream differentiation, this local clustering may contribute to the variability in differentiation efficiencies observed within and between cultures. We therefore hypothesized that controlling and directing the spontaneous clustering process would lead to more efficient and consistent induction of pancreatic endocrine fate. Micropatterning cells in adherent microwells prompted clustering, local cell density increases, and increased nuclear accumulation of PDX1 and NKX6.1. Improved differentiation profiles were associated with distinct filamentous actin architectures, suggesting a previously overlooked role for cell-driven morphogenetic changes in supporting pancreatic differentiation. This work demonstrates that confined differentiation in cell-adhesive micropatterns may provide a facile, scalable, and more reproducible manufacturing route to drive morphogenesis and produce well-differentiated pancreatic cell clusters.


Assuntos
Diferenciação Celular/fisiologia , Sangue Fetal/citologia , Proteínas de Homeodomínio/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Células Secretoras de Insulina/metabolismo , Transativadores/metabolismo , Citoesqueleto de Actina/metabolismo , Adulto , Adesão Celular , Células Cultivadas , Diabetes Mellitus Tipo 1/terapia , Humanos , Transplante das Ilhotas Pancreáticas , Fenótipo , Reação em Cadeia da Polimerase em Tempo Real
7.
PLoS One ; 15(1): e0227879, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31929603

RESUMO

Accumulating evidence suggests that Alzheimer's disease is associated with brain insulin resistance, as are some other types of dementia. Intranasal insulin administration has been suggested as a potential approach to overcoming brain insulin resistance and improving cognitive functions. Islet transplantation into the cranial subarachnoid cavity was used as an alternative route for insulin delivery into the brain. Recently, the authors showed the short-term beneficial cognitive effect of a small number of intracranially grafted islets in rats with cognitive dysfunction induced by intracerebroventricular administration of streptozotocin (icv-STZ). This was associated with continuous and safe insulin delivery to the rat brain. The current study investigated the long-term effect of intracranial grafting of islets on cognitive functioning in icv-STZ rats. Severe dementia, associated with obesity and cerebral amyloid-ß angiopathy, was induced in Lewis inbred rats by icv-STZ. Two months after icv-STZ, one hundred syngeneic islets were transplanted into the cranial subarachnoid space. Two and six months later, cognitive alterations were assessed by Morris water-maze tests. Islet graft survival was evaluated by immunohistochemical and biochemical assays. Improvement was found in spatial learning and memory of grafted rats as opposed to the sham-operated icv-STZ rats. The grafted islets showed intact morphology, intensive expression of insulin, glucagon and glucose transporter 2. Normoglycemic obesity and cerebral amyloid-ß angiopathy were found in both grafted and sham-operated icv-STZ rats. In conclusion, islet grafting into cranial subarachnoid space provides an efficient and safe approach for insulin delivery to the brain, leading to a long-term attenuation of icv-STZ-induced cognitive dysfunction.


Assuntos
Doença de Alzheimer/terapia , Transtornos Cognitivos/terapia , Insulina/biossíntese , Transplante das Ilhotas Pancreáticas/métodos , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Encéfalo/cirurgia , Cognição/fisiologia , Transtornos Cognitivos/metabolismo , Transtornos Cognitivos/patologia , Modelos Animais de Doenças , Hipocampo/metabolismo , Hipocampo/patologia , Hipocampo/cirurgia , Humanos , Ilhotas Pancreáticas/metabolismo , Aprendizagem em Labirinto , Memória/fisiologia , Ratos
8.
Adv Exp Med Biol ; 1212: 179-220, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31025308

RESUMO

Insulin-dependent diabetes mellitus or type 1 diabetes mellitus (T1DM) is an auto-immune condition characterized by the loss of pancreatic ß-cells. The curative approach for highly selected patients is the pancreas or the pancreatic islet transplantation. Nevertheless, these options are limited by a growing shortage of donor organs and by the requirement of immunosuppression.Xenotransplantation of porcine islets has been extensively investigated. Nevertheless, the strong xenoimmunity and the risk of transmission of porcine endogenous retroviruses, have limited their application in clinic. Generation of ß-like cells from stem cells is one of the most promising strategies in regenerative medicine. Embryonic, and more recently, adult stem cells are currently the most promising cell sources exploited to generate functional ß-cells in vitro. A number of studies demonstrated that stem cells could generate functional pancreatic organoids (POs), able to restore normoglycemia when implanted in different preclinical diabetic models. Nevertheless, a gradual loss of function and cell dead are commonly detected when POs are transplanted in immunocompetent animals. So far, the main issue to be solved is the post-transplanted islet loss, due to the host immune attack. To avoid this hurdle, nanotechnology has provided a number of polymers currently under investigation for islet micro and macro-encapsulation. These new approaches, besides conferring PO immune protection, are able to supply oxygen and nutrients and to preserve PO morphology and long-term viability.Herein, we summarize the current knowledge on bioengineered POs and the stem cell differentiation platforms. We also discuss the in vitro strategies used to generate functional POs, and the protocols currently used to confer immune-protection against the host immune attack (micro- and macro-encapsulation). In addition, the most relevant ongoing clinical trials, and the most relevant hurdles met to move towards clinical application are revised.


Assuntos
Diabetes Mellitus Tipo 1/terapia , Ilhotas Pancreáticas/citologia , Organoides/citologia , Medicina Regenerativa/métodos , Células-Tronco/citologia , Animais , Diferenciação Celular , Diabetes Mellitus Tipo 1/patologia , Humanos , Transplante das Ilhotas Pancreáticas/métodos
10.
Am J Surg ; 219(1): 99-105, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31023550

RESUMO

Total pancreatectomy with islet autotransplantation is a promising treatment for refractory chronic pancreatitis. We analyzed postoperative complications in 83 TPIAT patients and their impact on islet graft function. We examined patient demographics, preoperative risk factors, intraoperative variables, and 30- and 90-day postoperative morbidity and mortality. Daily insulin requirement, HbA1c, C-peptide levels, and narcotic requirements were analyzed before and after surgery. Adverse events were recorded, with postoperative complications graded according to the Clavien-Dindo classification. There was no mortality in this patient group. Postoperative complications occurred in 38 patients (45.7%). Patients with postoperative complications were readmitted significantly more often within 30 days (p = 0.01) and 90 days posttransplant (p < 0.0003) and had a significantly longer hospital stay (p = 0.004) and intensive care unit stay (p = 0.001). Insulin dependence and graft function assessed by HbA1c, C-Peptide and insulin requirements did not differ significantly by these complications. Postoperative complications after TPIAT are associated with longer hospital and intensive care unit stay and with readmission; however, the surgical complications do not affect islet graft function.


Assuntos
Transplante das Ilhotas Pancreáticas , Pancreatectomia , Pancreatite Crônica/cirurgia , Complicações Pós-Operatórias/epidemiologia , Adulto , Terapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pancreatectomia/métodos , Estudos Prospectivos , Transplante Autólogo , Resultado do Tratamento
12.
Integr Biol (Camb) ; 11(8): 331-341, 2019 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-31724717

RESUMO

Type 1 diabetes (T1D) results from the autoimmune destruction of ß-cells within the pancreatic islets of Langerhans. Clinical islet transplantation from healthy donors is proposed to ameliorate symptoms, improve quality of life, and enhance the life span of afflicted T1D patients. However, post-transplant outcomes are dependent on the survival of the transplanted islets, which relies on the engraftment of the islets with the recipient's vasculature among other factors. Treatment strategies to improve engraftment include combining islets with supporting cells including endothelial cells (EC) and mesenchymal stem cells (MSC), dynamic cells capable of robust immunomodulatory and vasculogenic effects. In this study, we developed an in vitro model of transplantation to investigate the cellular mechanisms that enhance rapid vascularization of heterotopic islet constructs. Self-assembled vascular beds of fluorescently stained EC served as reproducible in vitro transplantation sites. Heterotopic islet constructs composed of islets, EC, and MSC were transferred to vascular beds for modeling transplantation. Time-lapsed imaging was performed for analysis of the vascular bed remodeling for parameters of neo-vascularization. Moreover, sampling of media following modeled transplantation showed secretory profiles that were correlated with imaging analyses as well as with islet function using glucose-stimulated insulin secretion. Together, evidence revealed that heterotopic constructs consisting of islets, EC, and MSC exhibited the most rapid recruitment and robust branching of cells from the vascular beds suggesting enhanced neo-vascularization compared to islets alone and control constructs. Together, this evidence supports a promising cell transplantation strategy for T1D and also demonstrates a valuable tool for rapidly investigating candidate cellular therapies for transplantation.


Assuntos
Diabetes Mellitus Tipo 1/terapia , Transplante das Ilhotas Pancreáticas/instrumentação , Transplante das Ilhotas Pancreáticas/métodos , Ilhotas Pancreáticas/irrigação sanguínea , Ilhotas Pancreáticas/citologia , Transplante de Células-Tronco Mesenquimais , Células da Medula Óssea/citologia , Técnicas de Cultura de Células , Células Endoteliais/citologia , Glucose/metabolismo , Humanos , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Insulina/metabolismo , Secreção de Insulina , Microscopia Confocal , Neovascularização Fisiológica , Regiões Promotoras Genéticas , Fatores de Tempo
13.
Transplant Proc ; 51(10): 3428-3430, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31669073

RESUMO

Chronic pancreatitis (CP), secondary to a wide variety of etiologies, is a progressive and irreversible disease. Initially, CP is managed with endoscopic interventions, long-term analgesia for its associated chronic abdominal pain syndrome and pancreatic enzyme replacement for exocrine dysfunction. As the disease advances, pancreatic drainage procedures and partial resections are considered, but they leave diseased tissue behind and usually result in short-term relief only. Total pancreatectomy alone is widely viewed as a last resort treatment option because it causes brittle diabetes mellitus. However, total pancreatectomy with islet autotransplantation (TPIAT) can prevent the development of diabetes and cure the chronic pain syndrome. One serious, albeit rare, complication of TPIAT is (partial) portal vein thrombosis. Its incidence is probably about 5%. To prevent the occurrence of portal vein thrombosis, we propose herein, and have successfully performed, continuous real-time Doppler ultrasonography during the islet infusion to study portal vein and intrahepatic flow patterns, as well as changes in Doppler signals. Flow and signal changes may allow for timely adjustment of the infusion rate, before a marked increase in portal vein pressure is noted and decrease the risk of portal vein thrombosis.


Assuntos
Transplante das Ilhotas Pancreáticas/métodos , Monitorização Intraoperatória/métodos , Pancreatectomia/métodos , Veia Porta/diagnóstico por imagem , Ultrassonografia Doppler/métodos , Drenagem/efeitos adversos , Humanos , Pancreatite Crônica/cirurgia , Transplante Autólogo/métodos
14.
Nat Commun ; 10(1): 5262, 2019 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-31748525

RESUMO

Foreign body reaction (FBR) to implanted biomaterials and medical devices is common and can compromise the function of implants or cause complications. For example, in cell encapsulation, cellular overgrowth (CO) and fibrosis around the cellular constructs can reduce the mass transfer of oxygen, nutrients and metabolic wastes, undermining cell function and leading to transplant failure. Therefore, materials that mitigate FBR or CO will have broad applications in biomedicine. Here we report a group of zwitterionic, sulfobetaine (SB) and carboxybetaine (CB) modifications of alginates that reproducibly mitigate the CO of implanted alginate microcapsules in mice, dogs and pigs. Using the modified alginates (SB-alginates), we also demonstrate improved outcome of islet encapsulation in a chemically-induced diabetic mouse model. These zwitterion-modified alginates may contribute to the development of cell encapsulation therapies for type 1 diabetes and other hormone-deficient diseases.


Assuntos
Alginatos/química , Betaína/análogos & derivados , Encapsulamento de Células/métodos , Diabetes Mellitus Tipo 1/terapia , Reação a Corpo Estranho/prevenção & controle , Animais , Betaína/química , Ácido Carbônico , Proliferação de Células , Diabetes Mellitus Experimental , Cães , Fibrose , Transplante das Ilhotas Pancreáticas/métodos , Camundongos , Ratos , Suínos
15.
PLoS One ; 14(11): e0225665, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31774857

RESUMO

BACKGROUND: Hypoxia is one of the key factors affecting the survival of islet cells transplanted via the portal vein. Blood oxygen level dependent functional magnetic resonance imaging (BOLD-fMRI) is the only imaging technique that can detect the level of blood oxygen level in vivo. However, so far no study has indicated that BOLD-fMRI can be applied to monitor the liver oxygen level after islet transplantation. OBJECTIVE: To evaluate the value of Carbogen-challenge BOLD MRI in assessing the level of hypoxia in liver tissue after portal microcapsules implanted. METHODS: Fifty-one New Zealand rabbits were randomly divided into three experimental groups (15 in each group) were transplanted microencapsulated 1000 microbeads/kg (PV1 group), 3000 microbeads/kg (PV2 group), 5000 microbeads/kg (PV3 group), and 6 rabbits were injected with the same amount of saline as the control group, BOLD-fMRI was performed following carbogen breathing in each group after transplantation on 1d, 2d, 3d and 7d, T2* weighted image, R2* value and ΔR2* value parameters for the liver tissue. Pathological examinations including liver gross pathology, H&E staining and pimonidazole immunohistochemistry were performed after BOLD-fMRI. The differences of pathological results among each group were compared. The ΔR2* values and transplanted doses were analyzed. RESULTS AND CONCLUSIONS: ΔR2* values at the 1-3d and 7d after transplantation were significantly different in each groups (P<0.05). ΔR2* values decreased gradually with the increase of transplanted dose, and was negatively correlated with transplant dose at 3d after transplantation (r = -0.929, P <0.001). Liver histopathological examination showed that the degree of hypoxia of liver tissue increased with the increase of transplanted doses, Carbogen-challenge BOLD-fMRI can assess the degree of liver hypoxia after portal microcapsules implanted, which provided a monitoring method for early intervention.


Assuntos
Cápsulas/administração & dosagem , Dióxido de Carbono/administração & dosagem , Hipóxia/fisiopatologia , Transplante das Ilhotas Pancreáticas , Fígado/irrigação sanguínea , Imagem por Ressonância Magnética/métodos , Oxigênio/administração & dosagem , Veia Porta/patologia , Animais , Feminino , Processamento de Imagem Assistida por Computador , Fígado/patologia , Masculino , Coelhos
16.
Immunohorizons ; 3(10): 498-510, 2019 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-31636084

RESUMO

Immune cells express γ-aminobutyric acid receptors (GABA-R), and GABA administration can inhibit effector T cell responses in models of autoimmune disease. The pharmacokinetic properties of GABA, however, may be suboptimal for clinical applications. The amino acid homotaurine is a type A GABA-R (GABAA-R) agonist with good pharmacokinetics and appears safe for human consumption. In this study, we show that homotaurine inhibits in vitro T cell proliferation to a similar degree as GABA but at lower concentrations. In vivo, oral homotaurine treatment had a modest ability to reverse hyperglycemia in newly hyperglycemic NOD mice but was ineffective after the onset of severe hyperglycemia. In severely diabetic NOD mice, the combination of homotaurine and low-dose anti-CD3 treatment significantly increased 1) disease remission, 2) the percentages of splenic CD4+and CD8+ regulatory T cells compared with anti-CD3 alone, and 3) the frequencies of CD4+ and CD8+ regulatory T cells in the pancreatic lymph nodes compared with homotaurine monotherapy. Histological examination of their pancreata provided no evidence of the large-scale GABAA-R agonist-mediated replenishment of islet ß-cells that has been reported by others. However, we did observe a few functional islets in mice that received combined therapy. Thus, GABAA-R activation enhanced CD4+and CD8+ regulatory T cell responses following the depletion of effector T cells, which was associated with the preservation of some functional islets. Finally, we observed that homotaurine treatment enhanced ß-cell replication and survival in a human islet xenograft model. Hence, GABAA-R agonists, such as homotaurine, are attractive candidates for testing in combination with other therapeutic agents in type 1 diabetes clinical trials.


Assuntos
Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/efeitos dos fármacos , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 1/tratamento farmacológico , Agonistas GABAérgicos/farmacologia , Agonistas GABAérgicos/uso terapêutico , Muromonab-CD3/uso terapêutico , Taurina/análogos & derivados , Animais , Glicemia/efeitos dos fármacos , Diabetes Mellitus Experimental/imunologia , Diabetes Mellitus Tipo 1/imunologia , Sinergismo Farmacológico , Feminino , Humanos , Células Secretoras de Insulina/efeitos dos fármacos , Transplante das Ilhotas Pancreáticas , Camundongos Endogâmicos NOD , Camundongos SCID , Muromonab-CD3/farmacologia , Taurina/farmacologia , Taurina/uso terapêutico
17.
Nat Commun ; 10(1): 4602, 2019 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-31601796

RESUMO

The success of engineered cell or tissue implants is dependent on vascular regeneration to meet adequate metabolic requirements. However, development of a broadly applicable strategy for stable and functional vascularization has remained challenging. We report here highly organized and resilient microvascular meshes fabricated through a controllable anchored self-assembly method. The microvascular meshes are scalable to centimeters, almost free of defects and transferrable to diverse substrates, ready for transplantation. They promote formation of functional blood vessels, with a density as high as ~220 vessels mm-2, in the poorly vascularized subcutaneous space of SCID-Beige mice. We further demonstrate the feasibility of fabricating microvascular meshes from human induced pluripotent stem cell-derived endothelial cells, opening a way to engineer patient-specific microvasculature. As a proof-of-concept for type 1 diabetes treatment, we combine microvascular meshes and subcutaneously transplanted rat islets and achieve correction of chemically induced diabetes in SCID-Beige mice for 3 months.


Assuntos
Técnicas de Cultura de Células/instrumentação , Diabetes Mellitus Experimental/terapia , Transplante das Ilhotas Pancreáticas/métodos , Microvasos/crescimento & desenvolvimento , Animais , Bioengenharia , Técnicas de Cultura de Células/métodos , Diabetes Mellitus Experimental/complicações , Feminino , Células Endoteliais da Veia Umbilical Humana , Humanos , Hiperglicemia/terapia , Células-Tronco Pluripotentes Induzidas/citologia , Transplante das Ilhotas Pancreáticas/instrumentação , Masculino , Camundongos SCID , Microvasos/citologia , Microvasos/fisiologia , Neovascularização Fisiológica , Ratos Sprague-Dawley
18.
Ups J Med Sci ; 124(4): 228-237, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31623497

RESUMO

Background: Murine boundary cap-derived neural crest stem cells (NCSCs) are capable of enhancing islet function by stimulating beta cell proliferation as well as increasing the neural and vascular density in the islets both in vitro and in vivo. This study aimed to isolate NCSC-like cells from human bone marrow.Methods: CD271 magnetic cell separation and culture techniques were used to purify a NCSC-enriched population of human bone marrow. Analyses of the CD271+ and CD271- fractions in terms of protein expression were performed, and the capacity of the CD271+ bone marrow cells to form 3-dimensional spheres when grown under non-adherent conditions was also investigated. Moreover, the NCSC characteristics of the CD271+ cells were evaluated by their ability to migrate toward human islets as well as human islet-like cell clusters (ICC) derived from pluripotent stem cells.Results: The CD271+ bone marrow population fulfilled the criterion of being multipotent stem cells, having the potential to differentiate into glial cells, neurons as well as myofibroblasts in vitro. They had the capacity to form 3-dimensional spheres as well as an ability to migrate toward human islets, further supporting their NCSC identity. Additionally, we demonstrated similar migration features toward stem cell-derived ICC.Conclusion: The results support the NCSC identity of the CD271-enriched human bone marrow population. It remains to investigate whether the human bone marrow-derived NCSCs have the ability to improve transplantation efficacy of not only human islets but stem cell-derived ICC as well.


Assuntos
Técnicas de Cultura de Células , Separação Celular/métodos , Ilhotas Pancreáticas/citologia , Crista Neural/citologia , Células-Tronco Pluripotentes/citologia , Adapaleno/metabolismo , Adulto , Idoso , Células da Medula Óssea/citologia , Diferenciação Celular , Movimento Celular , Proliferação de Células , Humanos , Transplante das Ilhotas Pancreáticas , Masculino , Pessoa de Meia-Idade , Adulto Jovem
19.
Nat Commun ; 10(1): 4491, 2019 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-31582751

RESUMO

Maintaining long-term euglycemia after intraportal islet transplantation is hampered by the considerable islet loss in the peri-transplant period attributed to inflammation, ischemia and poor angiogenesis. Here, we show that viable and functional islet organoids can be successfully generated from dissociated islet cells (ICs) and human amniotic epithelial cells (hAECs). Incorporation of hAECs into islet organoids markedly enhances engraftment, viability and graft function in a mouse type 1 diabetes model. Our results demonstrate that the integration of hAECs into islet cell organoids has great potential in the development of cell-based therapies for type 1 diabetes. Engineering of functional mini-organs using this strategy will allow the exploration of more favorable implantation sites, and can be expanded to unlimited (stem-cell-derived or xenogeneic) sources of insulin-producing cells.


Assuntos
Diabetes Mellitus Tipo 1/terapia , Células Epiteliais/metabolismo , Transplante das Ilhotas Pancreáticas/métodos , Organoides/transplante , Engenharia Tecidual/métodos , Âmnio/citologia , Animais , Sobrevivência Celular , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/terapia , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/induzido quimicamente , Células Epiteliais/transplante , Sobrevivência de Enxerto , Xenoenxertos/irrigação sanguínea , Xenoenxertos/metabolismo , Xenoenxertos/transplante , Humanos , Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , Camundongos , Camundongos SCID , Organoides/irrigação sanguínea , Organoides/metabolismo , Ratos , Ratos Sprague-Dawley , Medicina Regenerativa/métodos , Esferoides Celulares , Estreptozocina , Técnicas de Cultura de Tecidos/métodos , Transplante Heterólogo/métodos
20.
J Diabetes Res ; 2019: 8712492, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31583254

RESUMO

Testicular structural and functional impairment is a serious complication in male diabetes mellitus (DM) patients that leads to impaired fertility in adulthood. In contrast to other endocrine therapies, islet transplantation (IT) can effectively prevent and even reverse diabetic nephropathy and myocardial damage. However, whether IT can alleviate diabetes-induced testicular injury remains unclear. In this study, we sought to investigate the effect of IT on diabetes-induced testicular damage. A diabetic rat model was established by streptozotocin injection. DM, IT, and insulin treatment (INS) groups were compared after 4 weeks of respective treatment. We confirmed that IT could effectively attenuate diabetes-induced testicular damage and recover sperm counts more extensively compared with INS in diabetic rats. In addition, significantly higher levels of superoxide dismutase (SOD) activity and lower contents of malondialdehyde (MDA) were detected in the testes of the IT group versus diabetic rats. Mechanism studies revealed that IT significantly activates the expression of Nrf-2, HO-1, and NQO-1 and inhibits upregulation of the NF-κB expression in response to DM, while INS only exhibit slight impact on the protein expression. Therefore, we speculate that IT may prevent the progression of testicular damage by downregulating oxidative stress and inhibiting inflammation via Nrf-2/HO-1 and NF-κB pathways.


Assuntos
Complicações do Diabetes/cirurgia , Diabetes Mellitus Experimental/cirurgia , Inflamação/metabolismo , Transplante das Ilhotas Pancreáticas , Estresse Oxidativo/fisiologia , Transdução de Sinais/fisiologia , Doenças Testiculares/cirurgia , Testículo/metabolismo , Animais , Complicações do Diabetes/tratamento farmacológico , Complicações do Diabetes/metabolismo , Complicações do Diabetes/patologia , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Heme Oxigenase (Desciclizante)/metabolismo , Hipoglicemiantes/farmacologia , Hipoglicemiantes/uso terapêutico , Inflamação/patologia , Insulina/farmacologia , Insulina/uso terapêutico , Masculino , Malondialdeído/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , NF-kappa B/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Transdução de Sinais/efeitos dos fármacos , Contagem de Espermatozoides , Doenças Testiculares/tratamento farmacológico , Doenças Testiculares/metabolismo , Doenças Testiculares/patologia , Testículo/efeitos dos fármacos , Testículo/patologia
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