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1.
Curr Protoc Toxicol ; 67: 14.13.1-14.13.27, 2016 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-26828329

RESUMO

Liver disease is a major global health concern. Liver cirrhosis is one of the leading causes of death in the world and currently the only therapeutic option for end-stage liver disease (e.g., acute liver failure, cirrhosis, chronic hepatitis, cholestatic diseases, metabolic diseases, and malignant neoplasms) is orthotropic liver transplantation. Transplantation of hepatocytes has been proposed and used as an alternative to whole organ transplant to stabilize and prolong the lives of patients in some clinical cases. Although these experimental therapies have demonstrated promising and beneficial results, their routine use remains a challenge due to the shortage of donor livers available for cell isolation, variable quality of those tissues, the potential need for lifelong immunosuppression in the transplant recipient, and high costs. Therefore, new therapeutic strategies and more reliable clinical treatments are urgently needed. Recent and continuous technological advances in the development of stem cells suggest they may be beneficial in this respect. In this review, we summarize the history of stem cell and induced pluripotent stem cell (iPSC) technology in the context of hepatic differentiation and discuss the potential applications the technology may offer for human liver disease modeling and treatment. This includes developing safer drugs and cell-based therapies to improve the outcomes of patients with currently incurable health illnesses. We also review promising advances in other disease areas to highlight how the stem cell technology could be applied to liver diseases in the future. © 2016 by John Wiley & Sons, Inc.


Assuntos
Hepatócitos/transplante , Células-Tronco Pluripotentes Induzidas , Hepatopatias , Regeneração Hepática , Medicina Regenerativa/métodos , Transplante de Células-Tronco , Células-Tronco Adultas/citologia , Células-Tronco Adultas/transplante , Animais , Diferenciação Celular , Modelos Animais de Doenças , Hepatócitos/citologia , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Pluripotentes Induzidas/transplante , Hepatopatias/etiologia , Hepatopatias/terapia
2.
Curr Protoc Toxicol ; 62: 14.12.1-23, 2014 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-25378242

RESUMO

Orthotopic liver transplantation remains the only curative treatment for many end-stage liver diseases, yet the number of patients receiving liver transplants remains limited by the number of organs available for transplant. There is a need for alternative therapies for liver diseases. The transplantation of isolated hepatocytes (liver cells) has been used as an experimental therapy for liver disease in a limited number of cases. Recently, the 100th case of hepatocyte transplantation was reported. This review discusses the history of the hepatocyte transplant field, the major discoveries that supported and enabled the first hepatocyte transplants, and reviews the cases and outcomes of the first 100 clinical transplants. Some of the problems that limit the application or efficacy of hepatocyte transplantation are discussed, as are possible solutions to these problems. In conclusion, hepatocyte transplants have proven effective particularly in cases of metabolic liver disease where reversal or amelioration of the characteristic symptoms of the disease is easily quantified. However, no patients have been completely corrected of a metabolic liver disease for a significant amount of time by hepatocyte transplantation alone. It is likely that future developments in new sources of cells for transplantation will be required before this cellular therapy can be fully implemented and available for large numbers of patients.


Assuntos
Hepatócitos/citologia , Hepatopatias/terapia , Humanos , Hepatopatias/patologia , Transplante de Fígado
3.
ACS Appl Mater Interfaces ; 6(22): 20234-41, 2014 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-25323064

RESUMO

Self-assembled monolayers (SAMs) of organic molecules can be used to tune interface energetics and thereby improve charge carrier injection at metal-semiconductor contacts. We investigate the compatibility of SAM formation with high-throughput processing techniques. Therefore, we examine the quality of SAMs, in terms of work function shift and chemical composition as measured with photoelectron and infrared spectroscopy and in dependency on molecular exposure during SAM formation. The functionality of the SAMs is determined by the performance increase of organic field-effect transistors upon SAM treatment of the source/drain contacts. This combined analytical and device-based approach enables us to minimize the necessary formation times via an optimization of the deposition conditions. Our findings demonstrate that SAMs composed of partially fluorinated alkanethiols can be prepared in ambient atmosphere from ethanol solution using immersion times as short as 5 s and still exhibit almost full charge injection functionality if process parameters are chosen carefully. This renders solution-processed SAMs compatible with high-throughput solution-based deposition techniques.

4.
Cell Transplant ; 23(1): 27-38, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23394081

RESUMO

Hepatocyte transplantation has been used to treat liver disease. The availability of cells for these procedures is quite limited. Human embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs) may be a useful source of hepatocytes for basic research and transplantation if efficient and effective differentiation protocols were developed and problems with tumorigenicity could be overcome. Recent evidence suggests that the cell of origin may affect hiPSC differentiation. Thus, hiPSCs generated from hepatocytes may differentiate back to hepatocytes more efficiently than hiPSCs from other cell types. We examined the efficiency of reprogramming adult and fetal human hepatocytes. The present studies report the generation of 40 hiPSC lines from primary human hepatocytes under feeder-free conditions. Of these, 37 hiPSC lines were generated from fetal hepatocytes, 2 hiPSC lines from normal hepatocytes, and 1 hiPSC line from hepatocytes of a patient with Crigler-Najjar syndrome, type 1. All lines were confirmed reprogrammed and expressed markers of pluripotency by gene expression, flow cytometry, immunocytochemistry, and teratoma formation. Fetal hepatocytes were reprogrammed at a frequency over 50-fold higher than adult hepatocytes. Adult hepatocytes were only reprogrammed with six factors, while fetal hepatocytes could be reprogrammed with three (OCT4, SOX2, NANOG) or four factors (OCT4, SOX2, NANOG, LIN28 or OCT4, SOX2, KLF4, C-MYC). The increased reprogramming efficiency of fetal cells was not due to increased transduction efficiency or vector toxicity. These studies confirm that hiPSCs can be generated from adult and fetal hepatocytes including those with genetic diseases. Fetal hepatocytes reprogram much more efficiently than adult hepatocytes, although both could serve as useful sources of hiPSC-derived hepatocytes for basic research or transplantation.


Assuntos
Reprogramação Celular/fisiologia , Células-Tronco Embrionárias/fisiologia , Hepatócitos/fisiologia , Células-Tronco Pluripotentes Induzidas/fisiologia , Adulto , Animais , Técnicas de Cultura de Células , Diferenciação Celular/fisiologia , Processos de Crescimento Celular/fisiologia , Células Cultivadas , Células-Tronco Embrionárias/citologia , Feminino , Hepatócitos/citologia , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Lactente , Recém-Nascido , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Adulto Jovem
5.
Stem Cell Res ; 11(1): 563-73, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23644508

RESUMO

UNLABELLED: Domino liver transplantation is a method used to increase the number of liver grafts available for orthotopic liver transplantation (OLT). Reports indicate that livers from patients with metabolic liver disease can be safely transplanted into select recipients if the donor's defect and the recipient's metabolic needs are carefully considered. The liver of patients with many types of metabolic liver disease is morphologically and biochemically normal, except for the mutation that characterizes that disease. Other biochemical functions normally performed by the liver are present and presumably "normal" in these hepatocytes. Hepatocytes were isolated from the liver of 35 organ donors and 35 liver tissues taken at OLT from patients with liver disease were analyzed for 9 different measures of viability and function. The data indicate that cells isolated from some diseased livers performed as well or better than those isolated from organ donors with respect to viability, cell yield, plating efficiency and in assays of liver function, including drug metabolism, conjugation reactions and ammonia metabolism. Cells from metabolic diseased livers rapidly and efficiently repopulated a mouse liver upon transplantation. CONCLUSIONS: As with domino liver transplantation, domino cell transplantation deserves consideration as method to extend the pool of available organs and cells for transplantation.


Assuntos
Hepatócitos/transplante , Hepatopatias/patologia , Transplante de Fígado/métodos , Fígado/patologia , Adolescente , Adulto , Animais , Criança , Pré-Escolar , Feminino , Hepatócitos/citologia , Hepatócitos/metabolismo , Humanos , Lactente , Fígado/metabolismo , Fígado/cirurgia , Hepatopatias/metabolismo , Hepatopatias/cirurgia , Masculino , Camundongos , Adulto Jovem
6.
Mol Genet Metab ; 109(2): 132-8, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23566440

RESUMO

Orthotopic liver transplant (OLT) significantly improves patient outcomes in maple syrup urine disease (MSUD; OMIM: 248600), yet organ shortages point to the need for alternative therapies. Hepatocyte transplantation has shown both clinical and preclinical efficacy as an intervention for metabolic liver diseases, yet the availability of suitable livers for hepatocyte isolation is also limited. Conversely, human amnion epithelial cells (hAEC) may have utility as a hepatocyte substitute, and they share many of the characteristics of pluripotent embryonic stem cells while lacking their safety and ethical concerns. We reported that like hepatocytes, transplantation of hAEC significantly improved survival and lifespan, normalized body weight, and significantly improved branched-chain amino acid (BCAA) levels in sera and brain in a transgenic murine model of intermediate maple syrup urine disease (imsud). In the current report, we detail the neural and peripheral metabolic improvements associated with hAEC transplant in imsud mice, including amino acids associated with bioenergetics, the urea cycle, as well as the neurotransmitter systems for serotonin, dopamine, and gamma-aminobutyric acid (GABA). This stem cell therapy results in significant global correction of the metabolic profile that characterizes the disease, both in the periphery and the central nervous system, the target organ for toxicity in iMSUD. The significant correction of the disease phenotype, coupled with the theoretical benefits of hAEC, particularly their lack of immunogenicity and tumorigenicity, suggests that human amnion epithelial cells deserve serious consideration for clinical application to treat metabolic liver diseases.


Assuntos
Aminoácidos/sangue , Âmnio/citologia , Células Epiteliais/transplante , Doença da Urina de Xarope de Bordo/terapia , Neurotransmissores/metabolismo , Animais , Encéfalo/metabolismo , Ciclo do Ácido Cítrico , Humanos , Doença da Urina de Xarope de Bordo/sangue , Camundongos , Camundongos Transgênicos
7.
Drug Metab Dispos ; 41(2): 296-304, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23129211

RESUMO

Little information is available in the literature regarding the expression and activity of transporters in fetal human liver or cultured cells. A synthetic progesterone structural analog, 17α-hydroxyprogesterone caproate (17-OHPC), is used in the prevention of spontaneous abortion in women with a history of recurrent miscarriage (habitual abortion). 17-OHPC has been reported to traverse the placental barrier and gain access to fetal circulation. In this study, the role of transporters in the disposition of 17-OHPC in fetal and adult human hepatocytes was examined. Progesterone metabolites have been reported to induce trans-inhibition of bile acid transporter, ABCB11. Thus, we investigated the effect of 17-OHPC or its metabolites on [(3)H]taurocholic acid transport in sandwich-cultured human fetal and adult hepatocytes. 17-OHPC was taken up rapidly into the cells and transported out partially by an active efflux process that was significantly inhibited by cold temperature, cyclosporine, verapamil, and rifampin. The active efflux mechanism was observed in both adult and fetal hepatocyte cultures. 17-OHPC produced a concentration-dependent inhibition of taurocholate efflux into canaliculi in sandwich-cultured adult and fetal human hepatocytes. However, given the high concentrations required to cause inhibition of these transport processes, no adverse effects would be anticipated from therapeutic levels of 17-OHPC. We also evaluated the expression of various hepatic transporters (ABCB1, ABCB4, SLCO1B1, SLCO1B3, SLCO2B1, ABCB11, SLC10A1, ABCC2, ABCC3, ABCC4, and ABCG2) in fetal and adult hepatocytes. With the exception of ABCB4, all transporters examined were expressed, albeit at lower mRNA levels in fetal hepatocytes compared with adults.


Assuntos
Hepatócitos/metabolismo , Hidroxiprogesteronas/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Ácido Taurocólico/metabolismo , Caproato de 17 alfa-Hidroxiprogesterona , Adulto , Fatores Etários , Idoso , Transporte Biológico , Células Cultivadas , Temperatura Baixa , Ciclosporina/farmacologia , Feminino , Idade Gestacional , Hepatócitos/efeitos dos fármacos , Humanos , Hidroxiprogesteronas/farmacologia , Cinética , Masculino , Proteínas de Membrana Transportadoras/efeitos dos fármacos , Proteínas de Membrana Transportadoras/genética , Pessoa de Meia-Idade , RNA Mensageiro/metabolismo , Rifampina/farmacologia , Verapamil/farmacologia , Adulto Jovem
8.
Hepatology ; 57(3): 1017-23, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23175463

RESUMO

UNLABELLED: There is improved survival and partial metabolic correction of a mouse intermediate maple syrup urine disease (iMSUD) model after allogenic hepatocyte transplantation, confirming that a small number of enzyme-proficient liver-engrafted cells can improve phenotype. However, clinical shortages of suitable livers for hepatocyte isolation indicate a need for alternative cell sources. Human amnion epithelial cells (hAECs) share stem cell characteristics without the latter's safety and ethical concerns and differentiate to hepatocyte-like cells. Eight direct hepatic hAEC transplantations were performed in iMSUD mice over the first 35 days beginning at birth; animals were provided a normal protein diet and sacrificed at 35 and 100 days. Treatment at the neonatal stage is clinically relevant for MSUD and may offer a donor cell engraftment advantage. Survival was significantly extended and body weight was normalized in iMSUD mice receiving hAEC transplantations compared with untreated iMSUD mice, which were severely cachectic and died ≤28 days after birth. Branched chain α-keto acid dehydrogenase enzyme activity was significantly increased in transplanted livers. The branched chain amino acids leucine, isoleucine, valine, and alloisoleucine were significantly improved in serum and brain, as were other large neutral amino acids. CONCLUSION: Placental-derived stem cell transplantation lengthened survival and corrected many amino acid imbalances in a mouse model of iMSUD. This highlights the potential for their use as a viable alternative clinical therapy for MSUD and other liver-based metabolic diseases.


Assuntos
Âmnio/citologia , Células Epiteliais/transplante , Doença da Urina de Xarope de Bordo/terapia , Placenta/citologia , Transplante de Células-Tronco/métodos , 3-Metil-2-Oxobutanoato Desidrogenase (Lipoamida)/genética , 3-Metil-2-Oxobutanoato Desidrogenase (Lipoamida)/metabolismo , Aminoácidos de Cadeia Ramificada/genética , Animais , Animais Recém-Nascidos , Peso Corporal/fisiologia , Encéfalo/crescimento & desenvolvimento , Encéfalo/patologia , Diferenciação Celular/fisiologia , Modelos Animais de Doenças , Células Epiteliais/citologia , Feminino , Hepatócitos/citologia , Humanos , Doença da Urina de Xarope de Bordo/genética , Doença da Urina de Xarope de Bordo/patologia , Camundongos , Camundongos Mutantes , Gravidez , Transplante Heterólogo
9.
Reproduction ; 139(3): 479-93, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19880674

RESUMO

Spermatogonial stem cells (SSCs) maintain spermatogenesis throughout the reproductive life of mammals. While A(single) spermatogonia comprise the rodent SSC pool, the identity of the stem cell pool in the primate spermatogenic lineage is not well established. The prevailing model is that primate spermatogenesis arises from A(dark) and A(pale) spermatogonia, which are considered to represent reserve and active stem cells respectively. However, there is limited information about how the A(dark) and A(pale) descriptions of nuclear morphology correlate with the clonal (A(single), A(paired), and A(aligned)), molecular (e.g. GFRalpha1 (GFRA1) and PLZF), and functional (SSC transplantation) descriptions of rodent SSCs. Thus, there is a need to investigate primate SSCs using criteria, tools, and approaches that have been used to investigate rodent SSCs over the past two decades. SSCs have potential clinical application for treating some cases of male infertility, providing impetus for characterizing and learning to manipulate these adult tissue stem cells in primates (nonhuman and human). This review recounts the development of a xenotransplant assay for functional identification of primate SSCs and progress dissecting the molecular and clonal characteristics of the primate spermatogenic lineage. These observations highlight the similarities and potential differences between rodents and primates regarding the SSC pool and the kinetics of spermatogonial self-renewal and clonal expansion. With new tools and reagents for studying primate spermatogonia, the field is poised to develop and test new hypotheses about the biology and regenerative capacity of primate SSCs.


Assuntos
Primatas/fisiologia , Roedores/fisiologia , Espermatogônias/fisiologia , Células-Tronco/fisiologia , Adulto , Animais , Proliferação de Células , Humanos , Masculino , Modelos Biológicos , Espermatogênese/fisiologia , Espermatogônias/citologia , Testículo/citologia , Testículo/fisiologia
10.
Crit Rev Biomed Eng ; 37(4-5): 377-98, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-20528732

RESUMO

Induced pluripotent stem (iPS) cells are human somatic cells that have been reprogrammed to a pluripotent state. Through several elegant technologies, we are now able to generate human iPS cells with disease genotypes that could serve as invaluable tools for human disease modeling. This could lead to an understanding of the root causes of a disease and to the development of effective prophylactic and therapeutic strategies for it. However, we are still far from generating fully functional liver cells from stem cells, including iPS cells, on in vitro culture systems. Tissue-engineering techniques have opened the window to inducing a functional fate for differentiated cells by providing a microenvironment that allows the maintenance of signals similar to those found in the natural microenvironment. Here we review the current technology to establish iPS cells and discuss strategies to generate human liver disease modeling using iPS cell technology in concert with bioengineering approaches.


Assuntos
Modelos Animais de Doenças , Células-Tronco Embrionárias/patologia , Células-Tronco Embrionárias/transplante , Hepatopatias/patologia , Hepatopatias/cirurgia , Células-Tronco Pluripotentes/patologia , Células-Tronco Pluripotentes/transplante , Animais , Humanos
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