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1.
Int J Mol Sci ; 21(19)2020 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-33003641

RESUMO

The limited regenerative capacity of the injured myocardium leads to remodeling and often heart failure. Novel therapeutic approaches are essential. Induced pluripotent stem cells (iPSC) differentiated into cardiomyocytes are a potential future therapeutics. We hypothesized that organ-specific reprogramed fibroblasts may serve an advantageous source for future cardiomyocytes. Moreover, exosomes secreted from those cells may have a beneficial effect on cardiac differentiation and/or function. We compared RNA from different sources of human iPSC using chip gene expression. Protein expression was evaluated as well as exosome micro-RNA levels and their impact on embryoid bodies (EBs) differentiation. Statistical analysis identified 51 genes that were altered (p ≤ 0.05), and confirmed in the protein level, cardiac fibroblasts-iPSCs (CF-iPSCs) vs. dermal fibroblasts-iPSCs (DF-iPSCs). Several miRs were altered especially miR22, a key regulator of cardiac hypertrophy and remodeling. Lower expression of miR22 in CF-iPSCs vs. DF-iPSCs was observed. EBs treated with these exosomes exhibited more beating EBs p = 0.05. vs. control. We identify CF-iPSC and its exosomes as a potential source for cardiac recovery induction. The decrease in miR22 level points out that our CF-iPSC-exosomes are naïve of congestive heart cell memory, making them a potential biological source for future therapy for the injured heart.


Assuntos
Exossomos/genética , Insuficiência Cardíaca/terapia , Células-Tronco Pluripotentes Induzidas/metabolismo , Miocárdio/metabolismo , Diferenciação Celular/genética , Exossomos/metabolismo , Fibroblastos/metabolismo , Coração/fisiopatologia , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/patologia , Humanos , MicroRNAs/genética , Miocárdio/patologia , Miócitos Cardíacos/metabolismo
2.
Hepatology ; 62(1): 265-78, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25808545

RESUMO

UNLABELLED: The liver is the main organ responsible for the modification, clearance, and transformational toxicity of most xenobiotics owing to its abundance in cytochrome P450 (CYP450) enzymes. However, the scarcity and variability of primary hepatocytes currently limits their utility. Human pluripotent stem cells (hPSCs) represent an excellent source of differentiated hepatocytes; however, current protocols still produce fetal-like hepatocytes with limited mature function. Interestingly, fetal hepatocytes acquire mature CYP450 expression only postpartum, suggesting that nutritional cues may drive hepatic maturation. We show that vitamin K2 and lithocholic acid, a by-product of intestinal flora, activate pregnane X receptor (PXR) and subsequent CYP3A4 and CYP2C9 expression in hPSC-derived and isolated fetal hepatocytes. Differentiated cells produce albumin and apolipoprotein B100 at levels equivalent to primary human hepatocytes, while demonstrating an 8-fold induction of CYP450 activity in response to aryl hydrocarbon receptor (AhR) agonist omeprazole and a 10-fold induction in response to PXR agonist rifampicin. Flow cytometry showed that over 83% of cells were albumin and hepatocyte nuclear factor 4 alpha (HNF4α) positive, permitting high-content screening in a 96-well plate format. Analysis of 12 compounds showed an R(2) correlation of 0.94 between TC50 values obtained in stem cell-derived hepatocytes and primary cells, compared to 0.62 for HepG2 cells. Finally, stem cell-derived hepatocytes demonstrate all toxicological endpoints examined, including steatosis, apoptosis, and cholestasis, when exposed to nine known hepatotoxins. CONCLUSION: Our work provides fresh insights into liver development, suggesting that microbial-derived cues may drive the maturation of CYP450 enzymes postpartum. Addition of these cues results in the first functional, inducible, hPSC-derived hepatocyte for predictive toxicology.


Assuntos
Técnicas de Cultura de Células , Hepatócitos/citologia , Ácido Litocólico/farmacologia , Células-Tronco Pluripotentes/efeitos dos fármacos , Vitamina K 2/farmacologia , Diferenciação Celular , Células Cultivadas , Citocromo P-450 CYP2C9/metabolismo , Citocromo P-450 CYP3A/metabolismo , Células-Tronco Embrionárias/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Hepatócitos/enzimologia , Humanos , Receptor de Pregnano X , Receptores de Esteroides/metabolismo , Análise de Sequência de RNA , Testes de Toxicidade Aguda , Vitamina K 2/análogos & derivados
3.
Proc Natl Acad Sci U S A ; 110(18): E1685-94, 2013 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-23589888

RESUMO

Proper expression and function of the cardiac pacemaker is a critical feature of heart physiology. Two main mechanisms have been proposed: (i) the "voltage-clock," where the hyperpolarization-activated funny current If causes diastolic depolarization that triggers action potential cycling; and (ii) the "Ca(2+) clock," where cyclical release of Ca(2+) from Ca(2+) stores depolarizes the membrane during diastole via activation of the Na(+)-Ca(2+) exchanger. Nonetheless, these mechanisms remain controversial. Here, we used human embryonic stem cell-derived cardiomyocytes (hESC-CMs) to study their autonomous beating mechanisms. Combined current- and voltage-clamp recordings from the same cell showed the so-called "voltage and Ca(2+) clock" pacemaker mechanisms to operate in a mutually exclusive fashion in different cell populations, but also to coexist in other cells. Blocking the "voltage or Ca(2+) clock" produced a similar depolarization of the maximal diastolic potential (MDP) that culminated by cessation of action potentials, suggesting that they converge to a common pacemaker component. Using patch-clamp recording, real-time PCR, Western blotting, and immunocytochemistry, we identified a previously unrecognized Ca(2+)-activated intermediate K(+) conductance (IK(Ca), KCa3.1, or SK4) in young and old stage-derived hESC-CMs. IK(Ca) inhibition produced MDP depolarization and pacemaker suppression. By shaping the MDP driving force and exquisitely balancing inward currents during diastolic depolarization, IK(Ca) appears to play a crucial role in human embryonic cardiac automaticity.


Assuntos
Células-Tronco Embrionárias/citologia , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/metabolismo , Nó Sinoatrial/citologia , Nó Sinoatrial/metabolismo , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Linhagem Celular , Células-Tronco Embrionárias/efeitos dos fármacos , Células-Tronco Embrionárias/metabolismo , Humanos , Modelos Cardiovasculares , Miócitos Cardíacos/citologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Pirazóis/farmacologia , Pirimidinas/farmacologia , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Nó Sinoatrial/efeitos dos fármacos , Tioureia/análogos & derivados , Tioureia/farmacologia
4.
J Cell Mol Med ; 19(8): 2006-18, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26153920

RESUMO

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmia characterized by syncope and sudden death occurring during exercise or acute emotion. CPVT is caused by abnormal intracellular Ca(2+) handling resulting from mutations in the RyR2 or CASQ2 genes. Because CASQ2 and RyR2 are involved in different aspects of the excitation-contraction coupling process, we hypothesized that these mutations are associated with different functional and intracellular Ca(²+) abnormalities. To test the hypothesis we generated induced Pluripotent Stem Cell-derived cardiomyocytes (iPSC-CM) from CPVT1 and CPVT2 patients carrying the RyR2(R420Q) and CASQ2(D307H) mutations, respectively, and investigated in CPVT1 and CPVT2 iPSC-CM (compared to control): (i) The ultrastructural features; (ii) the effects of isoproterenol, caffeine and ryanodine on the [Ca(2+) ]i transient characteristics. Our major findings were: (i) Ultrastructurally, CASQ2 and RyR2 mutated cardiomyocytes were less developed than control cardiomyocytes. (ii) While in control iPSC-CM isoproterenol caused positive inotropic and lusitropic effects, in the mutated cardiomyocytes isoproterenol was either ineffective, caused arrhythmias, or markedly increased diastolic [Ca(2+) ]i . Importantly, positive inotropic and lusitropic effects were not induced in mutated cardiomyocytes. (iii) The effects of caffeine and ryanodine in mutated cardiomyocytes differed from control cardiomyocytes. Our results show that iPSC-CM are useful for investigating the similarities/differences in the pathophysiological consequences of RyR2 versus CASQ2 mutations underlying CPVT1 and CPVT2 syndromes.


Assuntos
Calsequestrina/genética , Células-Tronco Pluripotentes Induzidas/patologia , Mutação/genética , Miócitos Cardíacos/patologia , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Taquicardia Ventricular/genética , Taquicardia Ventricular/patologia , Sequência de Bases , Cafeína/farmacologia , Sinalização do Cálcio/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Técnicas de Genotipagem , Humanos , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Células-Tronco Pluripotentes Induzidas/ultraestrutura , Isoproterenol/farmacologia , Dados de Sequência Molecular , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/ultraestrutura , Retículo Sarcoplasmático/efeitos dos fármacos , Retículo Sarcoplasmático/metabolismo , Retículo Sarcoplasmático/ultraestrutura
5.
Stem Cells ; 32(12): 3137-49, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25186014

RESUMO

Human embryonic stem cells (hESCs) represent a potential source of transplantable cells for regenerative medicine, but development of teratoma even in syngenic recipients represents a critical obstacle to safe stem cell-based therapies. We hypothesized that hESCs escape the immune surveillance by regulating the environmental immune system. Using cocultures of hESCs with allogenic peripheral blood mononuclear cells, we demonstrated that hESCs prevent proliferation and activation of human CD4+ T lymphocytes, an effect dependent upon monocytes. Altered expression of key signaling molecules responsible for the crosstalk of monocytes with T cells was detected in the presence of hESCs. Analyzing the mechanism of action, we demonstrated that hESCs were able to downregulate intracellular glutathione levels in both monocytes and CD4+ cells by suppressing glutamate cysteine ligase expression and to alter MHCII and CD80 expression in monocytes. These effects were achieved at least partially via TGF-beta signaling, and both monocyte phenotype and GCLC expression were affected by Caspase-3 proteolytic activity. Altogether, our results demonstrate a novel immune-suppressive mechanism used by hESCs.


Assuntos
Diferenciação Celular/fisiologia , Células Dendríticas/citologia , Células-Tronco Embrionárias Humanas/metabolismo , Ativação Linfocitária/imunologia , Transdução de Sinais , Linfócitos T/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Antígenos CD/imunologia , Diferenciação Celular/imunologia , Técnicas de Cocultura/métodos , Humanos , Monócitos/citologia , Transdução de Sinais/fisiologia , Linfócitos T/imunologia , Fator de Crescimento Transformador beta/imunologia
6.
J Cell Sci ; 125(Pt 19): 4640-50, 2012 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-22767507

RESUMO

The mechanisms underlying the immunomodulatory effects of mesenchymal stem cells (MSCs) have been investigated under extreme conditions of strong T cell activation, which induces the rapid death of activated lymphocytes. The objective of this study was to investigate these mechanisms in the absence of additional polyclonal activation. In co-cultures of peripheral mononuclear blood cells with human MSCs (hereafter referred to as hMSCs), we observed a striking decrease in the level of CD8 expression on CD8+ cells, together with decreased expression of CD28 and CD44, and impaired production of IFN-gamma and Granzyme B. This effect was specific to hMSCs, because it was not observed with several other cell lines. Downregulation of CD8 expression required CD14+ monocytes to be in direct contact with the CD8+ cells, whereas the effects of hMSCs on the CD14+ cells were essentially mediated by soluble factors. The CD14+ monocytes exhibited a tolerogenic pattern when co-cultured with hMSCs, with a clear decrease in CD80 and CD86 co-stimulatory molecules, and an increase in the inhibitory receptors ILT-3 and ILT-4. CD8+ cells that were preconditioned by MSCs had similar effects on monocytes and were able to inhibit lymphocyte proliferation. Injection of hMSCs in humanized NSG mice showed similar trends, in particular decreased levels of CD44 and CD28 in human immune cells. Our study demonstrates a new immunomodulation mechanism of action of hMSCs through the modulation of CD8+ cells towards a non-cytotoxic and/or suppressive phenotype. This mechanism of action has to be taken into account in clinical trials, where it should be beneficial in grafts and autoimmune diseases, but potentially detrimental in malignant diseases.


Assuntos
Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/imunologia , Tolerância Imunológica/imunologia , Células-Tronco Mesenquimais/citologia , Monócitos/citologia , Monócitos/imunologia , Adulto , Animais , Biomarcadores/metabolismo , Antígenos CD8/metabolismo , Moléculas de Adesão Celular/metabolismo , Regulação para Baixo , Feminino , Humanos , Imunização , Receptores de Lipopolissacarídeos/metabolismo , Ativação Linfocitária/genética , Células-Tronco Mesenquimais/metabolismo , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Fenótipo , Transcrição Gênica
7.
Circulation ; 125(1): 87-99, 2012 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-22095829

RESUMO

BACKGROUND: Pericytes represent a unique subtype of microvessel-residing perivascular cells with diverse angiogenic functions and multilineage developmental features of mesenchymal stem cells. Although various protocols for derivation of endothelial and/or smooth muscle cells from human pluripotent stem cells (hPSC, either embryonic or induced) have been described, the emergence of pericytes in the course of hPSC maturation has not yet been elucidated. METHODS AND RESULTS: We found that during hPSC development, spontaneously differentiating embryoid bodies give rise to CD105(+)CD90(+)CD73(+)CD31(-) multipotent clonogenic mesodermal precursors, which can be isolated and efficiently expanded. Isolated and propagated cells expressed characteristic pericytic markers, including CD146, NG2, and platelet-derived growth factor receptor ß, but not the smooth muscle cell marker α-smooth muscle actin. Coimplantation of hPSC-derived endothelial cells with pericytes resulted in functional and rapid anastomosis to the murine vasculature. Administration of pericytes into immunodeficient mice with limb ischemia promoted significant vascular and muscle regeneration. At day 21 after transplantation, recruited hPSC pericytes were found incorporated into recovered muscle and vasculature. CONCLUSIONS: Derivation of vasculogenic and multipotent pericytes from hPSC can be used for the development of vasculogenic models using multiple vasculogenic cell types for basic research and drug screening and can contribute to angiogenic regenerative medicine.


Assuntos
Extremidades/irrigação sanguínea , Isquemia/cirurgia , Células-Tronco Multipotentes/transplante , Pericitos/transplante , Células-Tronco Pluripotentes/transplante , Recuperação de Função Fisiológica/fisiologia , Animais , Células Endoteliais/transplante , Extremidades/cirurgia , Humanos , Isquemia/patologia , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos Nus , Camundongos SCID
8.
Circulation ; 125(7): 883-93, 2012 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-22261196

RESUMO

BACKGROUND: The sinoatrial node is the main impulse-generating tissue in the heart. Atrioventricular conduction block and arrhythmias caused by sinoatrial node dysfunction are clinically important and generally treated with electronic pacemakers. Although an excellent solution, electronic pacemakers incorporate limitations that have stimulated research on biological pacing. To assess the suitability of potential biological pacemakers, we tested the hypothesis that the spontaneous electric activity of human embryonic stem cell-derived cardiomyocytes (hESC-CMs) and induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) exhibit beat rate variability and power-law behavior comparable to those of human sinoatrial node. METHODS AND RESULTS: We recorded extracellular electrograms from hESC-CMs and iPSC-CMs under stable conditions for up to 15 days. The beat rate time series of the spontaneous activity were examined in terms of their power spectral density and additional methods derived from nonlinear dynamics. The major findings were that the mean beat rate of hESC-CMs and iPSC-CMs was stable throughout the 15-day follow-up period and was similar in both cell types, that hESC-CMs and iPSC-CMs exhibited intrinsic beat rate variability and fractal behavior, and that isoproterenol increased and carbamylcholine decreased the beating rate in both hESC-CMs and iPSC-CMs. CONCLUSIONS: This is the first study demonstrating that hESC-CMs and iPSC-CMs exhibit beat rate variability and power-law behavior as in humans, thus supporting the potential capability of these cell sources to serve as biological pacemakers. Our ability to generate sinoatrial-compatible spontaneous cardiomyocytes from the patient's own hair (via keratinocyte-derived iPSCs), thus eliminating the critical need for immunosuppression, renders these myocytes an attractive cell source as biological pacemakers.


Assuntos
Células-Tronco Embrionárias/citologia , Frequência Cardíaca , Células-Tronco Pluripotentes Induzidas/citologia , Miócitos Cardíacos/fisiologia , Carbacol/farmacologia , Frequência Cardíaca/efeitos dos fármacos , Humanos , Isoproterenol/farmacologia , Nó Sinoatrial/fisiologia
9.
Stem Cells ; 30(6): 1097-108, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22415928

RESUMO

While experimentally induced arrest of human embryonic stem cells (hESCs) in G1 has been shown to stimulate differentiation, it remains unclear whether the unperturbed G1 phase in hESCs is causally related to differentiation. Here, we use centrifugal elutriation to isolate and investigate differentiation propensities of hESCs in different phases of their cell cycle. We found that isolated G1 cells exhibit higher differentiation propensity compared with S and G2 cells, and they differentiate at low cell densities even under self-renewing conditions. This differentiation of G1 cells was partially prevented in dense cultures of these cells and completely abrogated in coculture with S and G2 cells. However, coculturing without cell-to-cell contact did not rescue the differentiation of G1 cells. Finally, we show that the subset of G1 hESCs with reduced phosphorylation of retinoblastoma has the highest propensity to differentiate and that the differentiation is preceded by cell cycle arrest. These results provide direct evidence for increased propensity of hESCs to differentiate in G1 and suggest a role for neighboring cells in preventing differentiation of hESCs as they pass through a differentiation sensitive, G1 phase.


Assuntos
Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Proteína do Retinoblastoma/metabolismo , Técnicas de Cultura de Células , Ciclo Celular , Pontos de Checagem do Ciclo Celular , Diferenciação Celular/fisiologia , Fase G1 , Humanos , Fosforilação
10.
Stem Cells ; 30(5): 898-909, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22367714

RESUMO

Approximately 6 million people worldwide are suffering from severe visual impairments or blindness due to corneal diseases. Corneal allogeneic transplantation is often required to restore vision; however, shortage in corneal grafts and immunorejections remain major challenges. The molecular basis of corneal diseases is poorly understood largely due to lack of appropriate cellular models. Here, we described a robust differentiation of human-induced pluripotent stem cells (hiPSCs) derived from hair follicles or skin fibroblasts into corneal epithelial-like cells. We found that BMP4, coupled with corneal fibroblast-derived conditioned medium and collagen IV allowed efficient corneal epithelial commitment of hiPSCs in a manner that recapitulated corneal epithelial lineage development with high purity. Organotypic reconstitution assays suggested the ability of these cells to stratify into a corneal-like epithelium. This model allowed us identifying miR-450b-5p as a molecular switch of Pax6, a major regulator of eye development. miR-450b-5p and Pax6 were reciprocally distributed at the presumptive epidermis and ocular surface, respectively. miR-450b-5p inhibited Pax6 expression and corneal epithelial fate in vitro, altogether, suggesting that by repressing Pax6, miR-450b-5p triggers epidermal specification of the ectoderm, while its absence allows ocular epithelial development. Additionally, miR-184 was detectable in early eye development and corneal epithelial differentiation of hiPSCs. The knockdown of miR-184 resulted in a decrease in Pax6 and K3, in line with recent findings showing that a point mutation in miR-184 leads to corneal dystrophy. Altogether, these data indicate that hiPSCs are valuable for modeling corneal development and may pave the way for future cell-based therapy.


Assuntos
Linhagem da Célula/fisiologia , Córnea/embriologia , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , MicroRNAs/biossíntese , Modelos Biológicos , Células-Tronco Pluripotentes/metabolismo , Animais , Diferenciação Celular/fisiologia , Córnea/citologia , Proteínas do Olho/biossíntese , Proteínas do Olho/genética , Proteínas de Homeodomínio/biossíntese , Proteínas de Homeodomínio/genética , Humanos , Camundongos , MicroRNAs/genética , Fator de Transcrição PAX6 , Fatores de Transcrição Box Pareados/biossíntese , Fatores de Transcrição Box Pareados/genética , Células-Tronco Pluripotentes/citologia , Proteínas Repressoras/biossíntese , Proteínas Repressoras/genética
11.
Am J Obstet Gynecol ; 208(3): 213.e1-6, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23433325

RESUMO

OBJECTIVE: Maternal infection or inflammation may induce fetal inflammatory responses associated with fetal injury and cerebral palsy. We sought to assess the inflammation-associated neuroprotective potential of prophylactic N-acetyl-cysteine (NAC). We examined the effect of NAC on prevention of maternal lipopolysaccharide (LPS)-induced neonatal brain injury using magnetic resonance imaging. STUDY DESIGN: Pregnant Sprague Dawley dams (n = 5-8) at embryonic day 18 received intraperitoneal injection of LPS or saline at time 0. Animals were randomized to receive 2 intravenous injections of NAC or saline (time -30 and 120 minutes). Pups were delivered spontaneously and allowed to mature until postnatal day 25. Female offspring were examined by magnetic resonance brain imaging and analyzed using voxel-based analysis after spatial normalization. T2 relaxation time was used to assess white matter injury and diffusion tensor imaging for apparent diffusion coefficient (ADC) to assess white and gray matter injury. RESULTS: Offspring of LPS-treated dams exhibited significantly increased T2 levels and increased ADC levels in white and gray matter (eg, hypothalamus, motor cortex, corpus callosum, thalamus, hippocampus), consistent with diffuse cerebral injury. In contrast, offspring of NAC-treated LPS dams demonstrated similar T2 and ADC levels as control in both white and gray matter. CONCLUSION: Maternal NAC treatment significantly reduced evidence of neonatal brain injury associated with maternal LPS. These studies suggest that maternal NAC therapy may be effective in human deliveries associated with maternal/fetal inflammation.


Assuntos
Acetilcisteína/farmacologia , Animais Recém-Nascidos , Lesões Encefálicas/prevenção & controle , Encéfalo/efeitos dos fármacos , Transmissão Vertical de Doenças Infecciosas , Inflamação/prevenção & controle , Prenhez , Efeitos Tardios da Exposição Pré-Natal/prevenção & controle , Animais , Encéfalo/patologia , Lesões Encefálicas/induzido quimicamente , Lesões Encefálicas/patologia , Feminino , Inflamação/induzido quimicamente , Inflamação/patologia , Lipopolissacarídeos , Imageamento por Ressonância Magnética , Gravidez , Efeitos Tardios da Exposição Pré-Natal/patologia , Ratos , Ratos Sprague-Dawley
12.
J Cell Mol Med ; 16(3): 468-82, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22050625

RESUMO

Sudden cardiac death caused by ventricular arrhythmias is a disastrous event, especially when it occurs in young individuals. Among the five major arrhythmogenic disorders occurring in the absence of a structural heart disease is catecholaminergic polymorphic ventricular tachycardia (CPVT), which is a highly lethal form of inherited arrhythmias. Our study focuses on the autosomal recessive form of the disease caused by the missense mutation D307H in the cardiac calsequestrin gene, CASQ2. Because CASQ2 is a key player in excitation contraction coupling, the derangements in intracellular Ca(2+) handling may cause delayed afterdepolarizations (DADs), which constitute the mechanism underlying CPVT. To investigate catecholamine-induced arrhythmias in the CASQ2 mutated cells, we generated for the first time CPVT-derived induced pluripotent stem cells (iPSCs) by reprogramming fibroblasts from skin biopsies of two patients, and demonstrated that the iPSCs carry the CASQ2 mutation. Next, iPSCs were differentiated to cardiomyocytes (iPSCs-CMs), which expressed the mutant CASQ2 protein. The major findings were that the ß-adrenergic agonist isoproterenol caused in CPVT iPSCs-CMs (but not in the control cardiomyocytes) DADs, oscillatory arrhythmic prepotentials, after-contractions and diastolic [Ca(2+) ](i) rise. Electron microscopy analysis revealed that compared with control iPSCs-CMs, CPVT iPSCs-CMs displayed a more immature phenotype with less organized myofibrils, enlarged sarcoplasmic reticulum cisternae and reduced number of caveolae. In summary, our results demonstrate that the patient-specific mutated cardiomyocytes can be used to study the electrophysiological mechanisms underlying CPVT.


Assuntos
Agonistas Adrenérgicos beta/farmacologia , Calsequestrina/genética , Isoproterenol/farmacologia , Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , Taquicardia Ventricular/patologia , Adulto , Cálcio/metabolismo , Sinalização do Cálcio , Calsequestrina/metabolismo , Diferenciação Celular , Criança , Acoplamento Excitação-Contração , Feminino , Fibroblastos/metabolismo , Fibroblastos/patologia , Genes Recessivos , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Pluripotentes Induzidas/patologia , Masculino , Potenciais da Membrana , Mutação de Sentido Incorreto , Miocárdio/patologia , Miócitos Cardíacos/patologia , Taquicardia Ventricular/genética , Taquicardia Ventricular/metabolismo
13.
Arch Gynecol Obstet ; 286(4): 983-8, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22648447

RESUMO

PURPOSE: To evaluate the learning curve of senior urogynecologic surgeons performing laparoscopic sacral colpopexy (LSCP) and to assess outcomes and complications of LSCP. METHODS: We conducted a retrospective study of 47 consecutive women who underwent LSCP for pelvic organ prolapse repair between March 2009 and December 2010 at one tertiary medical center. Preoperative, intraoperative, postoperative, and demographic data were retrieved from patients' electronic charts. Pelvic organ support was assessed objectively using the Pelvic Organ Prolapse Quantification scale (POP-Q). Anatomic failure was determined as POP-Q stage ≥ II. RESULTS: The mean age of patients was 58 years (range 35-73 years). Seven (15 %) who opted to retain their uterus underwent sacrohysteropexies. The median POP-Q was III (II-IV). Of the 47 operations, 96 % (45) were completed by laparoscopy. The duration of surgery decreased as experience of the surgical team increased, from a mean of 196 ± 62 min for the first 15 cases to 162 ± 30 min for the subsequent 30. Four patients (9 %) presented with recurrence of prolapse; three (7 %) had de novo stress urinary incontinence; two sustained a cystotomy during adhesiolysis, and one had a port-site hernia. CONCLUSIONS: LSCP is a safe and effective treatment for pelvic organ prolapse, with very few complications. Following the first 15 cases of one surgical team, operative time decreased considerably.


Assuntos
Procedimentos Cirúrgicos em Ginecologia , Prolapso de Órgão Pélvico/cirurgia , Adulto , Idoso , Feminino , Procedimentos Cirúrgicos em Ginecologia/efeitos adversos , Humanos , Laparoscopia , Curva de Aprendizado , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
14.
J Cell Mol Med ; 15(11): 2539-51, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21883888

RESUMO

Induced pluripotent stem cells (iPSC) are generated from fully differentiated somatic cells that were reprogrammed into a pluripotent state. Human iPSC which can be obtained from various types of somatic cells such as fibroblasts or keratinocytes can differentiate into cardiomyocytes (iPSC-CM), which exhibit cardiac-like transmembrane action potentials, intracellular Ca(2+) transients and contractions. While major features of the excitation-contraction coupling of iPSC-CM have been well-described, very little is known on the ultrastructure of these cardiomyocytes. The ultrastructural features of 31-day-old (post-plating) iPSC-CM generated from human hair follicle keratinocytes (HFKT-iPSC-CM) were analysed by electron microscopy, and compared with those of human embryonic stem-cell-derived cardiomyocytes (hESC-CM). The comparison showed that cardiomyocytes from the two sources share similar proprieties. Specifically, HFKT-iPSC-CM and hESC-CM, displayed ultrastructural features of early and immature phenotype: myofibrils with sarcomeric pattern, large glycogen deposits, lipid droplets, long and slender mitochondria, free ribosomes, rough endoplasmic reticulum, sarcoplasmic reticulum and caveolae. Noteworthy, the SR is less developed in HFKT-iPSC-CM. We also found in both cell types: (1) 'Ca(2+)-release units', which connect the peripheral sarcoplasmic reticulum with plasmalemma; and (2) intercellular junctions, which mimic intercalated disks (desmosomes and fascia adherens). In conclusion, iPSC and hESC differentiate into cardiomyocytes of comparable ultrastructure, thus supporting the notion that iPSC offer a viable option for an autologous cell source for cardiac regenerative therapy.


Assuntos
Diferenciação Celular , Células-Tronco Embrionárias/citologia , Células-Tronco Pluripotentes Induzidas/citologia , Miócitos Cardíacos/ultraestrutura , Cálcio/metabolismo , Cavéolas/ultraestrutura , Células Cultivadas , Células-Tronco Embrionárias/fisiologia , Retículo Endoplasmático/ultraestrutura , Acoplamento Excitação-Contração , Fibroblastos/citologia , Folículo Piloso/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/fisiologia , Queratinócitos/citologia , Potenciais da Membrana , Microscopia Eletrônica , Mitocôndrias Cardíacas/ultraestrutura , Contração Miocárdica , Retículo Sarcoplasmático/ultraestrutura
15.
J Cell Mol Med ; 15(1): 38-51, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20041972

RESUMO

In view of the therapeutic potential of cardiomyocytes derived from induced pluripotent stem (iPS) cells (iPS-derived cardiomyocytes), in the present study we investigated in iPS-derived cardiomyocytes, the functional properties related to [Ca(2+) ](i) handling and contraction, the contribution of the sarcoplasmic reticulum (SR) Ca(2+) release to contraction and the b-adrenergic inotropic responsiveness. The two iPS clones investigated here were generated through infection of human foreskin fibroblasts (HFF) with retroviruses containing the four human genes: OCT4, Sox2, Klf4 and C-Myc. Our major findings showed that iPS-derived cardiomyocytes: (i) express cardiac specific RNA and proteins; (ii) exhibit negative force-frequency relations and mild (compared to adult) post-rest potentiation; (iii) respond to ryanodine and caffeine, albeit less than adult cardiomyocytes, and express the SR-Ca(2+) handling proteins ryanodine receptor and calsequestrin. Hence, this study demonstrates that in our cardiomyocytes clones differentiated from HFF-derived iPS, the functional properties related to excitation-contraction coupling, resemble in part those of adult cardiomyocytes.


Assuntos
Células-Tronco Pluripotentes Induzidas/citologia , Miócitos Cardíacos/metabolismo , Animais , Cafeína/farmacologia , Cálcio/metabolismo , Calsequestrina/genética , Calsequestrina/metabolismo , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Fibroblastos/metabolismo , Imunofluorescência , Prepúcio do Pênis/citologia , Expressão Gênica , Humanos , Fator 4 Semelhante a Kruppel , Fatores de Transcrição Kruppel-Like/genética , Masculino , Camundongos , Camundongos SCID , Contração Miocárdica/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Fator 3 de Transcrição de Octâmero/genética , Proteínas Proto-Oncogênicas c-myc/genética , RNA Mensageiro/metabolismo , Rianodina/farmacologia , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Fatores de Transcrição SOXB1/genética , Retículo Sarcoplasmático/metabolismo , Teratoma/metabolismo , Teratoma/patologia
16.
Hum Reprod ; 26(10): 2874-7, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21784738

RESUMO

BACKGROUND: It is now well established that a GnRH agonist (GnRHa) ovulation trigger completely prevents ovarian hyperstimulation syndrome. However, early studies, using conventional luteal support, showed inferior clinical results following a GnRHa trigger compared with a conventional hCG trigger in normal responder IVF patients. We here present a novel approach for luteal support after a GnRHa trigger. METHODS Normal responder patients who failed at least one previous IVF attempt, during which a conventional hCG trigger was used, were consecutively enrolled in the study. A GnRH antagonist-based ovarian stimulation protocol was used in combination with a GnRHa trigger (Triptorelin 0.2 mg). The luteal phase was supported with a total of two boluses of 1500 IU hCG: on the day of oocyte retrieval and 4 days later. Neither progesterone nor estradiol was administered for luteal support. RESULTS: The mean age was 33.8 years. The mean (± SD) numbers of oocytes and fertilized oocytes were 6.7 (± 2.5) and 3.6 (± 1.7), respectively. All 15 patients had embryo transfers and 11 patients conceived. On the day of pregnancy test (14 days after retrieval), the mean serum E(2) and progesterone levels were 6607 (± 3789) and 182 (± 50) nmol/l, respectively. Of the pregnancies, seven are ongoing, while four ended as miscarriages. CONCLUSIONS: These preliminary results suggest that two boluses of 1500 IU hCG revert the luteolysis after a GnRHa trigger in the normo-responder patient. Importantly, no additional luteal support is needed. The novel concept combines the potential advantages of a physiological dual trigger (LH and FSH) with a simple, patient friendly, luteal support.


Assuntos
Gonadotropina Coriônica/metabolismo , Corpo Lúteo/metabolismo , Hormônio Liberador de Gonadotropina/agonistas , Ovulação/efeitos dos fármacos , Progesterona/metabolismo , Adulto , Estrogênios/metabolismo , Feminino , Fertilização , Fertilização in vitro/métodos , Humanos , Infertilidade/terapia , Oócitos/citologia , Síndrome de Hiperestimulação Ovariana/tratamento farmacológico , Gravidez , Resultado da Gravidez , Estudos Prospectivos
17.
Neurourol Urodyn ; 30(7): 1291-4, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21404320

RESUMO

AIM: To explore the relationship between urinary incontinence and genital sensory functioning in females with sexual dysfunction disorders. METHODS: A retrospective consecutive chart review was conducted for all women who were referred to our tertiary female urology clinic with a primary complaint of sexual dysfunction between October 1999 and January 2009. Our study sample included 177 women, all of whom underwent a thorough clinical evaluation. Urinary incontinence was diagnosed based on clinical history and physical examination by a urogynecologist. The Genital Thermal and Vibratory Sensory Analyzer (GSA) was used for sensory testing in the genital area. Independent t-test and multivariate linear regression were used for statistical analysis. RESULTS: Of the 177 study patients (median age 34, range 18-68), 63 (36%) had urinary incontinence. Women with urinary incontinence were found to be less sensitive to warm, cold, and vibratory thresholds at both the anterior and the posterior vaginal wall and the clitoral area (P < 0.05). CONCLUSIONS: Women with urinary incontinence and sexual dysfunction are less sensitive to all sensory testing in the genital region than women with sexual dysfunction alone. This relationship may be attributable to afferent nerve damage and the critical role it may play in the etiology of urinary incontinence.


Assuntos
Genitália Feminina/inervação , Sensação , Disfunções Sexuais Fisiológicas/etiologia , Incontinência Urinária/complicações , Adolescente , Adulto , Vias Aferentes/fisiopatologia , Idoso , Temperatura Baixa , Técnicas de Diagnóstico Neurológico , Feminino , Temperatura Alta , Humanos , Israel , Modelos Lineares , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos , Disfunções Sexuais Fisiológicas/diagnóstico , Disfunções Sexuais Fisiológicas/fisiopatologia , Incontinência Urinária/diagnóstico , Incontinência Urinária/fisiopatologia , Vibração , Adulto Jovem
18.
Methods Mol Biol ; 2235: 119-125, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33576973

RESUMO

Human pluripotent stem cells (hPSCs), either embryonic or induced, offer a plentiful platform for derivation of multiple cell types. Pericytes, generated from hPSCs, are multipotent precursors with vasculogenic features that exhibit high proliferation capability in long-term cultures. Administration of hPSC-pericytes into ischemic murine hind limb is associated with therapeutic angiogenesis and attenuation of muscle wasting. Here, we describe the protocol for derivation of large numbers of pericytes from spontaneously differentiating hPSC-embryoid bodies.


Assuntos
Técnicas de Cultura de Células/métodos , Diferenciação Celular/fisiologia , Pericitos/metabolismo , Animais , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Humanos , Pericitos/citologia , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/metabolismo
19.
Front Endocrinol (Lausanne) ; 12: 635405, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34025576

RESUMO

Background: Cell therapy of diabetes aims at restoring the physiological control of blood glucose by transplantation of functional pancreatic islet cells. A potentially unlimited source of cells for such transplantations would be islet cells derived from an in vitro differentiation of human pluripotent stem cells (hESC/hiPSC). The islet-like clusters (ILC) produced by the known differentiation protocols contain various cell populations. Among these, the ß-cells that express both insulin and the transcription factor Nkx6.1 seem to be the most efficient to restore normoglycemia in diabetes animal models. Our aim was to find markers allowing selection of these efficient cells. Methods: Functional Cell-Capture Screening (FCCS) was used to identify markers that preferentially capture the cells expressing both insulin and Nkx6.1, from hESC-derived ILC cells. In order to test whether selection for such markers could improve cell therapy in diabetic mouse models, we used ILC produced from a clinical-grade line of hESC by a refined differentiation protocol adapted to up-scalable bioreactors. Re-aggregated MACS sorted cells were encapsulated in microspheres made of alginate modified to reduce foreign body reaction. Implantation was done intraperitoneally in STZ-treated C57BL/6 immuno-competent mice. Results: CD49A (integrin alpha1) was identified by FCCS as a marker for cells that express insulin (or C-peptide) as well as Nkx6.1 in ILC derived by hESC differentiation. The ILC fraction enriched in CD49A + cells rapidly reduced glycemia when implanted in diabetic mice, whereas mice receiving the CD49A depleted population remained highly diabetic. CD49A-enriched ILC cells also produced higher levels of human C-peptide in the blood of transplanted mice. However, the difference between CD49A-enriched and total ILC cells remained small. Another marker, CD26 (DPP4), was identified by FCCS as binding insulin-expressing cells which are Nkx6.1 negative. Depletion of CD26 + cells followed by enrichment for CD49A + cells increased insulin+/Nkx6.1+ cells fraction to ~70%. The CD26 - /CD49A + enriched ILC exhibited improved function over non-sorted ILC or CD49A + cells in diabetic mice and maintain prolonged blood C-peptide levels. Conclusions: Refining the composition of ILC differentiated from hPSC by negative selection to remove cells expressing CD26 and positive selection for CD49A expressing cells could enable more effective cell therapy of diabetes.


Assuntos
Diabetes Mellitus Experimental/metabolismo , Dipeptidil Peptidase 4/biossíntese , Integrina alfa1/biossíntese , Transplante das Ilhotas Pancreáticas , Ilhotas Pancreáticas/metabolismo , Células-Tronco Pluripotentes/metabolismo , Animais , Peptídeo C/biossíntese , Diferenciação Celular , Separação Celular , Proteínas de Homeodomínio/metabolismo , Humanos , Insulina/metabolismo , Secreção de Insulina , Células Secretoras de Insulina/citologia , Camundongos , Camundongos Endogâmicos C57BL , Microesferas
20.
Crit Rev Eukaryot Gene Expr ; 20(1): 51-9, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20528737

RESUMO

Cardiovascular diseases are the most frequent cause of death in the industrialized world, with the main contributor being myocardial infarction. Given the high morbidity and mortality rates associated with congestive heart failure, the shortage of donor hearts for transplantation, complications resulting from immunosuppression, and long-term failure of transplanted organs, regeneration of the diseased myocardium by cell transplantation is an attractive therapeutic modality. Because of their remarkable capacity for expansion and unquestioned cardiac potential, pluripotent human embryonic stem cells (hESC) represent an attractive candidate cell source for obtaining cardiomyocytes. Moreover, a number of recent reports have shown that hESC-derived cardiomyocytes (hESC-CM) survive after transplantation into infarcted rodent hearts, form stable cardiac implants, and result in preserved contractile function. Although the latter successes give good reason for optimism, considerable challenges remain in the successful application of hESC-CM to cardiac repair. Because it is desired that the transplanted cells fully integrate within the diseased myocardium, contribute to its contractile performance, and respond appropriately to various physiological stimuli, it is of crucial importance to be familiar with their functional properties. Therefore, this review describes the characteristics of hESC-CM, including their transcriptional profile, structural and electrophysiological properties, ion channel expression, excitation-contraction coupling, and neurohumoral responsiveness.


Assuntos
Células-Tronco Embrionárias/transplante , Infarto do Miocárdio/cirurgia , Miócitos Cardíacos/citologia , Miócitos Cardíacos/transplante , Adulto , Canais de Cálcio Tipo L/genética , Eletrofisiologia/métodos , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/fisiologia , Humanos , Contração Miocárdica/fisiologia , Miocárdio/citologia , Miócitos Cardíacos/fisiologia , Receptores Adrenérgicos beta/genética , Receptores Adrenérgicos beta/fisiologia , Receptores Muscarínicos/genética , Receptores Muscarínicos/fisiologia , Regeneração , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição/genética , Transcrição Gênica
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