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1.
Int J Cardiol ; 354: 68-74, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-35202739

RESUMO

BACKGROUND: Bone marrow transplantation (BMT) has significantly improved survival rates in various hematological malignancies. However, this has led to an increased prevalence of long-term cardiotoxicity, particularly in those with prior anthracycline (AC) therapy. OBJECTIVES: To evaluate changes in left atrial (LA) volume and function, including LA strain, in BMT patients with prior AC exposure and evaluate its utility as a marker of diastolic dysfunction. METHODS: This was a cross-sectional analysis of 79 BMT patients with prior AC exposure who underwent a comprehensive surveillance transthoracic echocardiogram compared to age-matched healthy volunteers. Left ventricular (LV) and LA parameters were evaluated between the 2 groups. BMT patients were stratified using traditional measures of diastolic function and additionally utilizing LA strain. RESULTS: LV systolic dysfunction with reduced LVEF (13/79) or global longitudinal strain (29/79) was present in BMT patients. There were no differences in LA volumes between the two groups. LA reservoir strain (30.1 ± 11.2% vs 34.1 ± 9.6%, p < 0.001) and LA conduit strain (13.6 ± 8.4% vs 17.0 ± 10.5%, p < 0.001) were reduced in the BMT group compared to controls. LA reservoir strain had modest correlation with mitral annular e' velocity (r = 0.468, p < 0.001). Using current diastolic function guidelines, 26/79 BMT patients had evidence of diastolic dysfunction. However, utilizing LA reservoir strain, an additional 35 patients were identified. CONCLUSIONS: LA strain can identify early diastolic dysfunction in BMT patients with prior AC treatment. With diastolic dysfunction known to precede systolic dysfunction post AC, changes in LA reservoir strain may identify more patients with cardiac dysfunction, prompting increased surveillance and treatment.


Assuntos
Transplante de Medula Óssea , Disfunção Ventricular Esquerda , Antraciclinas/efeitos adversos , Medula Óssea , Transplante de Medula Óssea/efeitos adversos , Estudos Transversais , Átrios do Coração/diagnóstico por imagem , Humanos , Disfunção Ventricular Esquerda/induzido quimicamente , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/epidemiologia , Função Ventricular Esquerda
2.
Heart ; 108(7): 550-557, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34301770

RESUMO

OBJECTIVE: To evaluate the utility of two-dimensional multiplanar speckle tracking strain to assess for cardiotoxicity post allogenic bone marrow transplantation (BMT) for haematological conditions. METHODS: Cross-sectional study of 120 consecutive patients post-BMT (80 pretreated with anthracyclines (BMT+AC), 40 BMT alone) recruited from a late effects haematology clinic, compared with 80 healthy controls, as part of a long-term cardiotoxicity surveillance study (mean duration from BMT to transthoracic echocardiogram 6±6 years). Left ventricular global longitudinal strain (LV GLS), global circumferential strain (LV GCS) and right ventricular free wall strain (RV FWS) were compared with traditionl parameters of function including LV ejection fraction (LVEF) and RV fractional area change. RESULTS: LV GLS (-17.7±3.0% vs -20.2±1.9%), LV GCS (-14.7±3.5% vs -20.4±2.1%) and RV FWS (-22.6±4.7% vs -28.0±3.8%) were all significantly (p=0.001) reduced in BMT+AC versus controls, while only LV GCS (-15.9±3.5% vs -20.4±2.1%) and RV FWS (-23.9±3.5% vs -28.0±3.8%) were significantly (p=0.001) reduced in BMT group versus controls. Even in patients with LVEF >53%, ~75% of patients in both BMT groups demonstrated a reduction in GCS. CONCLUSION: Multiplanar strain identifies a greater number of BMT patients with subclinical LV dysfunction rather than by GLS alone, and should be evaluated as part of post-BMT patient surveillence. Reduction in GCS is possibly due to effects of preconditioning, and is not fully explained by AC exposure.


Assuntos
Cardiotoxicidade , Disfunção Ventricular Esquerda , Medula Óssea , Transplante de Medula Óssea/efeitos adversos , Cardiotoxicidade/etiologia , Estudos Transversais , Humanos , Volume Sistólico , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/etiologia , Função Ventricular Esquerda
3.
Cytotherapy ; 23(12): 1074-1084, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34588150

RESUMO

BACKGROUND AIMS: Mesenchymal stromal cells (MSCs) have been shown to improve cardiac function after injury and are the subject of ongoing clinical trials. In this study, the authors tested the cardiac regenerative potential of an induced pluripotent stem cell-derived MSC (iPSC-MSC) population (Cymerus MSCs) in a rat model of myocardial ischemia-reperfusion (I/R). Furthermore, the authors compared this efficacy with bone marrow-derived MSCs (BM-MSCs), which are the predominant cell type in clinical trials. METHODS: Four days after myocardial I/R injury, rats were randomly assigned to (i) a Cymerus MSC group (n = 15), (ii) a BM-MSC group (n = 15) or (iii) a vehicle control group (n = 14). For cell-treated animals, a total of 5 × 106 cells were injected at three sites within the infarcted left ventricular (LV) wall. RESULTS: One month after cell transplantation, Cymerus MSCs improved LV function (assessed by echocardiography) compared with vehicle and BM-MSCs. Interestingly, Cymerus MSCs enhanced angiogenesis without sustained engraftment or significant impact on infarct scar size. Suggesting safety, Cymerus MSCs had no effect on inducible tachycardia or the ventricular scar heterogeneity that provides a substrate for cardiac re-entrant circuits. CONCLUSIONS: The authors here demonstrate that intra-myocardial administration of iPSC-MSCs (Cymerus MSCs) provide better therapeutic effects compared with conventional BM-MSCs in a rodent model of myocardial I/R. Because of its manufacturing scalability, iPSC-MSC therapy offers an exciting opportunity for an "off-the-shelf" stem cell therapy for cardiac repair.


Assuntos
Células-Tronco Pluripotentes Induzidas , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Infarto do Miocárdio , Animais , Infarto do Miocárdio/terapia , Miocárdio , Ratos
4.
Front Nutr ; 8: 652094, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33842524

RESUMO

Tart cherries (TC) are a rich source of polyphenols that elicit antioxidant and anti-inflammatory effects. As a consequence, the effects of TC derived supplements on markers of human health, exercise performance and sleep have been investigated. Supplementation protocols have been highly variable across studies and the dose of bioactive compounds used has often been poorly characterized. Specific and non-specific analytical methods were employed for measuring the total polyphenol and anthocyanin content in TC supplements. This review critically analyses the supplementation protocols and the analytical methods used for the characterization of TC supplements, culminating in recommendations for good practice in the analysis and reporting of the polyphenol content and profile of TC products. A literature search was conducted using PubMed/Medline and Web of Science up to May 4th, 2020, including studies published in all years prior. Only articles written in English that provided a TC dietary supplement as opposed to fresh whole TC were included in this review. Forty-three studies were identified as eligible and included for analysis in this review. The studies investigated the effects of TC supplementation on various aspects of human health, exercise recovery and performance and sleep. Twenty studies conducted an analysis of TC supplement and reported total polyphenol/anthocyanin content. Six studies did not report the polyphenol content of the TC supplement used. Seventeen studies reported the TC supplement polyphenol content but this was derived from previously published studies and presumably different supplement batches. The duration of the supplementation protocol ranged from acute supplementation to 84 days, meanwhile the total polyphenol and anthocyanin dose ranged from 143 to 2,140 mg/day and 15 to 547 mg/day, respectively. Due to the variety of specific and non-specific analytical methods used, the relative efficacy of different doses and polyphenol blends cannot reliably be extrapolated from critical analysis of the literature. Future studies should conduct an analysis of the study supplement batch. In addition to analysis and reporting of total polyphenol content, specific analytical methods such as HPLC UV/MS should be used to quantify total and individual anthocyanin contents.

5.
J AOAC Int ; 104(1): 122-128, 2021 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-33099632

RESUMO

BACKGROUND: Kombucha is a fermented beverage made with tea, sugar, and a symbiotic colony of bacteria and yeast that is usually marketed as a non-alcoholic beverage. Products must contain <0.5% and <1.1% alcohol by volume in the United States and Canada respectively to be classified as non-alcoholic products. Prior studies have found that Kombucha beverages can become very acidic and may contain levels of alcohol above 1% which can be a potential health risk to children and the developing fetus during pregnancy. OBJECTIVE: Given the public safety concerns and legal requirements associated with the level of alcohol within Kombucha beverages, there is a need for accurate and reliable methods. Herein we describe the validation of a sensitive, rapid, and simple Headspace Gas Chromatographic method with mass spectrometric detection for determining ethanol in Kombucha. METHODS: Method performance characteristics measured included linearity, accuracy, precision, limit of detection (LOD), and limit of quantification (LOQ) as per AOAC International guideline Appendix K Part 1. Performance was evaluated against the AOAC Standard Method Performance Requirements 2016.001 for determination of ethanol in Kombucha. RESULTS: The linear dynamic range for this method was confirmed over the range of 0.025 to 2.47% ABV. The LOD and LOQ were determined to be 0.0002% and 0.002% ABV, respectively. With a spike recovery of 102% for accuracy and precision of RSDr ≤ 4% the method met the SMPR requirements within the analytical range. CONCLUSIONS: The results of this validation study demonstrated the method is fit for the purpose of quantifying ethanol in Kombucha and is suitable for rapid and easy integration by laboratories to ensure that regulatory requirements are met.


Assuntos
Etanol , Laboratórios , Canadá , Criança , Etanol/análise , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Espectrometria de Massas
6.
Reprod Toxicol ; 95: 95-103, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32428649

RESUMO

In utero exposure to arsenite (iAs) is known to increase disease risks later in life. We investigated the effect of in utero exposure to iAs in the drinking water on metabolic and reproductive parameters in male mouse offspring at postnatal and adult stages. Pregnant CD-1 mice were exposed to iAs (as sodium arsenite) in the drinking water at 0 (control), 10 ppb (EPA standard for drinking water), and 42.5 ppm (tumor-inducing dose in mice) from embryonic day (E) 10-18. At birth, pups were fostered to unexposed females. Male offspring exposed to 10 ppb in utero exhibited increase in body weight at birth when compared to controls. Male offspring exposed to 42.5 ppm in utero showed a tendency for increased body weight and a smaller anogenital distance. The body weight in iAs-exposed pups continued to increase significantly compared to control at 3 weeks and 11 weeks of age. At 5 months of age, iAs-exposed males exhibited greater body fat content and glucose intolerance. Male offspring exposed to 10 ppb in utero had higher circulating levels of leptin compared to control. In addition, males exposed to 42.5 ppm in utero exhibited decreased total number of pups born compared to controls and lower average number of litters sired over a six-month period. These results indicate that in utero exposure to iAs at either human relevant concentration or tumor-inducing concentration is a potential cause of developmental origin of metabolic and reproductive dysfunction in adult male mice.


Assuntos
Arsenitos/toxicidade , Efeitos Tardios da Exposição Pré-Natal , Animais , Peso Corporal/efeitos dos fármacos , Feminino , Fertilidade/efeitos dos fármacos , Glucose/metabolismo , Leptina/sangue , Masculino , Troca Materno-Fetal , Camundongos , Gravidez , Espermatozoides/efeitos dos fármacos , Testículo/efeitos dos fármacos , Testículo/metabolismo , Testículo/patologia
7.
Sci Transl Med ; 12(524)2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31894101

RESUMO

Therapies that target scar formation after myocardial infarction (MI) could prevent ensuing heart failure or death from ventricular arrhythmias. We have previously shown that recombinant human platelet-derived growth factor-AB (rhPDGF-AB) improves cardiac function in a rodent model of MI. To progress clinical translation, we evaluated rhPDGF-AB treatment in a clinically relevant porcine model of myocardial ischemia-reperfusion. Thirty-six pigs were randomized to sham procedure or balloon occlusion of the proximal left anterior descending coronary artery with 7-day intravenous infusion of rhPDGF-AB or vehicle. One month after MI, rhPDGF-AB improved survival by 40% compared with vehicle, and cardiac magnetic resonance imaging showed left ventricular (LV) ejection fraction improved by 11.5%, driven by reduced LV end-systolic volumes. Pressure volume loop analyses revealed improved myocardial contractility and energetics after rhPDGF-AB treatment with minimal effect on ventricular compliance. rhPDGF-AB enhanced angiogenesis and increased scar anisotropy (high fiber alignment) without affecting overall scar size or stiffness. rhPDGF-AB reduced inducible ventricular tachycardia by decreasing heterogeneity of the ventricular scar that provides a substrate for reentrant circuits. In summary, we demonstrated that rhPDGF-AB promotes post-MI cardiac wound repair by altering the mechanics of the infarct scar, resulting in robust cardiac functional improvement, decreased ventricular arrhythmias, and improved survival. Our findings suggest a strong translational potential for rhPDGF-AB as an adjunct to current MI treatment and possibly to modulate scar in other organs.


Assuntos
Cicatriz/patologia , Infarto do Miocárdio/patologia , Fator de Crescimento Derivado de Plaquetas/farmacologia , Animais , Arritmias Cardíacas/complicações , Arritmias Cardíacas/patologia , Arritmias Cardíacas/fisiopatologia , Arteríolas/efeitos dos fármacos , Arteríolas/patologia , Arteríolas/fisiopatologia , Cicatriz/complicações , Cicatriz/tratamento farmacológico , Cicatriz/fisiopatologia , Colágeno/metabolismo , Fibrose , Testes de Função Cardíaca/efeitos dos fármacos , Ventrículos do Coração/efeitos dos fármacos , Ventrículos do Coração/patologia , Ventrículos do Coração/fisiopatologia , Humanos , Contração Miocárdica/efeitos dos fármacos , Infarto do Miocárdio/complicações , Infarto do Miocárdio/tratamento farmacológico , Infarto do Miocárdio/fisiopatologia , Neovascularização Fisiológica/efeitos dos fármacos , Fator de Crescimento Derivado de Plaquetas/uso terapêutico , Proteínas Recombinantes/farmacologia , Análise de Sobrevida , Suínos , Cicatrização/efeitos dos fármacos
8.
Anim Reprod Sci ; 207: 61-72, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31208850

RESUMO

Semen cryopreservation is a very important technique for assisted reproduction; however, the cryopreservation process is harmful because it results in a reduction in sperm motility and viability, and leads to premature signals of capacitation, resulting in lesser than desirable fertility rates after artificial insemination. A fraction of seminal plasma, enriched in proteins that contain type II fibronectin domains (FNII) can reverse molecular indicators of cryo-capacitation. The beneficial effects of these proteins, however, depend on the relative abundance in seminal plasma. To create a safe additive for improving frozen sperm functionality, in the present study there was cloning and expression of a recombinant peptide containing four FNII domains (named TrxA-FNIIx4-His6) and evaluation of its effect after addition to frozen/thawed ram sperm. The cDNA for this protein was expressed in E. coli and after denaturation and re-naturalization of the protein, toxicity and binding capacity were assessed. By fluorescent labelling assessment, there was binding of the protein to the thawed sperm. At the two doses used (0.15 and 0.3 µM), TrxA-FNIIx4-His6 had the capacity to reverse the molecular indicators of cryo-capacitation as indicated by the reduction on phosphorylated substrates of PKA. Furthermore, the supplementation with this protein resulted in a normal capacitation process as evidenced by the increase in the in vitro fertilization rate when the greatest concentration of the protein was evaluated (73.25 ±â€¯2.95; 40.13 ±â€¯11.82 for 0.3 µM and control, respectively). There was no effect of protein supplementation on sperm objective motility compared to untreated sperm. In conclusion, the use of TrxA-FNIIx4-His6 is a promising biotechnological approach for cryopreserving ram sperm and maintaining sperm viability.


Assuntos
Criopreservação/veterinária , Fertilização in vitro/veterinária , Peptídeos/farmacologia , Proteínas de Plasma Seminal/farmacologia , Capacitação Espermática/efeitos dos fármacos , Animais , Clonagem Molecular , Criopreservação/métodos , Crioprotetores/química , Crioprotetores/metabolismo , Crioprotetores/farmacologia , Escherichia coli/genética , Escherichia coli/metabolismo , Fertilização in vitro/métodos , Fibronectinas/química , Fibronectinas/genética , Inseminação Artificial/métodos , Inseminação Artificial/veterinária , Masculino , Peptídeos/genética , Domínios Proteicos/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacologia , Análise do Sêmen/veterinária , Preservação do Sêmen/métodos , Preservação do Sêmen/veterinária , Proteínas de Plasma Seminal/química , Proteínas de Plasma Seminal/genética , Ovinos , Capacitação Espermática/fisiologia , Motilidade dos Espermatozoides/efeitos dos fármacos , Espermatozoides/efeitos dos fármacos
9.
J AOAC Int ; 102(3): 878-882, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30227904

RESUMO

Background: Kombucha is a nonalcoholic, fermented tea beverage that has recently received negative attention because of documented concentrations of ethanol in excess of allowable limits of ≥0.5% alcohol by volume (ABV). Objective: Our previously reported headspace GC with flame-ionization detection (GC-FID) method was adopted by the AOAC Expert Review Panel as First Action Official MethodSM 2016.12 in September 2016 based on published single-laboratory validation study results. This paper describes the corresponding multilaboratory study using this method to further validate its performance parameters. Methods: Four laboratories participated in the study and received practice samples, test samples, reference standards, and detailed protocols. Eight kombucha samples sent out to laboratories were randomly assigned sample numbers and were blinded in terms of content and identity. Each laboratory analyzed all samples using the GC-FID method and reported their results. Results: Cochran's C-test and single and double Grubbs' tests were used to identify and remove outliers. Horwitz ratio values for all samples were between 0.5 and 1.7. As per the Standard Method Performance Requirements (SMPRs®), all samples within the analytical range of 0.1-2.0 ABV% had RSDR values <6%. Conclusions: The results from this study demonstrate the evaluated GC-FID method meets the SMPR requirements and is fit for purpose for detecting ethanol in kombucha products. Highlights: Kombucha, a nonalcoholic, fermented beverage, has been found to contain ≥0.5% ABV. First Action Official Method 2016.12, a headspace GC-FID method for determining ethanol in kombucha, is supported by a multilaboratory study.


Assuntos
Etanol/análise , Chá de Kombucha/análise , Ionização de Chama/métodos
10.
Endocrinology ; 155(12): 4964-74, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25181385

RESUMO

Peritubular myoid (PM) cells surround the seminiferous tubule and together with Sertoli cells form the cellular boundary of the spermatogonial stem cell (SSC) niche. However, it remains unclear what role PM cells have in determining the microenvironment in the niche required for maintenance of the ability of SSCs to undergo self-renewal and differentiation into spermatogonia. Mice with a targeted disruption of the androgen receptor gene (Ar) in PM cells experienced a progressive loss of spermatogonia, suggesting that PM cells require testosterone (T) action to produce factors influencing SSC maintenance in the niche. Other studies showed that glial cell line-derived neurotrophic factor (GDNF) is required for SSC self-renewal and differentiation of SSCs in vitro and in vivo. This led us to hypothesize that T-regulated GDNF expression by PM cells contributes to the maintenance of SSCs. This hypothesis was tested using an adult mouse PM cell primary culture system and germ cell transplantation. We found that T induced GDNF expression at the mRNA and protein levels in PM cells. Furthermore, when thymus cell antigen 1-positive spermatogonia isolated from neonatal mice were cocultured with PM cells with or without T and transplanted to the testes of germ cell-depleted mice, the number and length of transplant-derived colonies was increased considerably by in vitro T treatment. These results support the novel hypothesis that T-dependent regulation of GDNF expression in PM cells has a significant influence on the microenvironment of the niche and SSC maintenance.


Assuntos
Células-Tronco Adultas/fisiologia , Fator Neurotrófico Derivado de Linhagem de Célula Glial/metabolismo , Testículo/fisiologia , Testosterona/fisiologia , Células-Tronco Adultas/transplante , Animais , Técnicas de Cocultura , Masculino , Camundongos Endogâmicos C57BL , Espermatogônias/fisiologia , Testículo/citologia
11.
Nutr Cancer ; 58(2): 188-96, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17640165

RESUMO

Essiac, a widely consumed, sparsely tested herbal tea, was evaluated for preparation consistency and antiproliferative effects on prostate cancer cells and xenografts. High performance liquid chromatography (HPLC) was used to compare different lots of Essiac and evaluate extraction consistency by comparing peak areas in concentrated preparations. Repeated analysis of one lot showed < 2% RSD between corresponding peaks. Absolute peak areas varied widely between lots, but similarity in relative size of corresponding peaks was observed. Cytotoxic effects of Essiac were tested in vitro by crystal violet assay and analysis of cell cycle distribution by flow cytometry, but no differences between control and treatment groups was observed. Paclitaxel was used as a positive control in cell cycle analysis and was the only treatment which showed significant effects on cell cycle distribution. Toxicity in nude mice was tested, and efficacy in inhibiting PC-3 xenograft growth. No toxicity or tumour size difference was observed dosing up to 240 mg/kg QD, over 28 days, excepting the positive control group treated with paclitaxel. Ki-67 and PCNA expression was analyzed in treated tumors, but no difference in expression of either marker was observed. These evaluations suggest Essiac has no marked antiproliferative effect on the models tested.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Ciclo Celular/efeitos dos fármacos , Extratos Vegetais/análise , Extratos Vegetais/farmacologia , Neoplasias da Próstata/tratamento farmacológico , Animais , Área Sob a Curva , Cromatografia Líquida de Alta Pressão/métodos , Relação Dose-Resposta a Droga , Citometria de Fluxo , Imuno-Histoquímica , Antígeno Ki-67/metabolismo , Masculino , Camundongos , Camundongos Nus , Paclitaxel/farmacologia , Extratos Vegetais/toxicidade , Antígeno Nuclear de Célula em Proliferação/metabolismo , Distribuição Aleatória , Transplante Heterólogo
12.
Clin Nutr ; 26(2): 252-63, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17337101

RESUMO

BACKGROUND & AIMS: Lycopene has been credited with a number of health benefits including a decrease in prostate cancer risk. Our study investigates the molecular mechanism underlying anti-cancer activity of lycopene-based products in androgen-responsive (LNCaP) and androgen-independent (PC3) cells. METHODS: The effect of lycopene-based agents on prostate cancer growth and survival were examined using proliferation assays, bromodeoxyuridine incorporation and flow cytometric analysis of cellular DNA content. Biochemical effects of lycopene treatment were investigated by immunoblotting for changes in the absolute levels and phosphorylation states of cell cycle regulatory and signalling proteins. RESULTS: LNCaP and PC3 cells treated with the lycopene-based agents undergo mitotic arrest, accumulating in G0/G1 phase. Immunoblot screening indicated that lycopene's antiproliferative effects are likely achieved through a block in G1/S transition mediated by decreased levels of cyclins D1 and E and cyclin dependent kinase 4 and suppressed Retinoblastoma phosphorylation. These responses correlated with decreased insulin-like growth factor-I receptor expression and activation, increased insulin-like growth factor binding protein 2 expression and decreased AKT activation. Exposure to lycopene at doses as low as 10 nM for 48 h induced a profound apoptotic response in LNCaP cells. In contrast PC3 cells were resistant to apoptosis at doses up to 1 microM. CONCLUSIONS: Lycopene exposure can suppress phosphatidylinositol 3-kinase-dependent proliferative and survival signalling in androgen-responsive LNCaP and androgen-independent PC3 cells suggesting that the molecular mechanisms for the cytostatic and cytotoxic actions of lycopene involve induction of G0/G1 cell cycle arrest. This study supports further examination of lycopene as a potential agent for both the prevention and treatment of prostate cancer.


Assuntos
Anticarcinógenos/farmacologia , Apoptose/efeitos dos fármacos , Carotenoides/farmacologia , Ciclo Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Androgênios/metabolismo , Androgênios/farmacologia , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Citometria de Fluxo , Fase G1/efeitos dos fármacos , Humanos , Licopeno , Masculino , Fosforilação , Neoplasias da Próstata , Fase de Repouso do Ciclo Celular/efeitos dos fármacos
13.
Reproduction ; 129(4): 435-42, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15798018

RESUMO

There is some evidence suggesting that Ca2+ is involved in processes that occur during the development and function of spermatozoa. Calcium-dependent proteins, such as calmodulin, are expressed during mammalian spermatogenesis further suggesting that Ca2+ takes part in its regulation. However, the precise roles of Ca2+ in spermatogenesis remain to be elucidated. Calpains are a family of Ca(2+)-dependent cysteine proteases whose members are expressed ubiquitously or in a tissue-specific manner. Calpain has been demonstrated to mediate specific Ca(2+)-dependent processes including cell fusion, mitosis and meiosis. We herein followed the expression pattern of calpain's ubiquitous isoforms, 1 and 2, throughout spermatogenesis at the RNA and protein levels by RT-PCR and Western blotting analysis. Both RNA and protein studies revealed that these isoforms are expressed in all spermatogenic cells. The expression of calpain 1 levels is slightly higher in spermatocytes entering the meiotic phase. Both calpain isoforms are also expressed in mouse spermatozoa and are localized to the acrosomal cap. Inducing capacitated spermatozoa to undergo the acrosome reaction in the presence of a selective calpain inhibitor significantly reduced the acrosome reaction rate in a dose-dependent manner. Thus, calpain, a pluripotential protease with numerous substrates, may serve as an effector in more than one pathway in the complex process of spermatogenesis and in the events preceding fertilization, such as the acrosome reaction.


Assuntos
Calpaína/análise , Espermatogênese/fisiologia , Espermatozoides/química , Reação Acrossômica/efeitos dos fármacos , Animais , Western Blotting/métodos , Calpaína/antagonistas & inibidores , Calpaína/genética , Dipeptídeos/farmacologia , Relação Dose-Resposta a Droga , Imuno-Histoquímica/métodos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Microscopia Confocal , RNA/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Espermatócitos/química
14.
Dev Biol ; 248(2): 331-42, 2002 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-12167408

RESUMO

A-kinase anchoring proteins (AKAPs) tether cyclic AMP-dependent protein kinases and thereby localize phosphorylation of target proteins and initiation of signal-transduction processes triggered by cyclic AMP. AKAPs can also be scaffolds for kinases and phosphatases and form macromolecular complexes with other proteins involved in signal transduction. Akap4 is transcribed only in the postmeiotic phase of spermatogenesis and encodes the most abundant protein in the fibrous sheath, a novel cytoskeletal structure present in the principal piece of the sperm flagellum. Previous studies indicated that cyclic AMP-dependent signaling processes are important in the regulation of sperm motility, and gene targeting was used here to test the hypothesis that AKAP4 is a scaffold for protein complexes involved in regulating flagellar function. Sperm numbers were not reduced in male mice lacking AKAP4, but sperm failed to show progressive motility and male mice were infertile. The fibrous sheath anlagen formed, but the definitive fibrous sheath did not develop, the flagellum was shortened, and proteins usually associated with the fibrous sheath were absent or substantially reduced in amount. However, the other cytoskeletal components of the flagellum were present and appeared fully developed. We conclude that AKAP4 is a scaffold protein required for the organization and integrity of the fibrous sheath and that effective sperm motility is lost in the absence of AKAP4 because signal transduction and glycolytic enzymes fail to become associated with the fibrous sheath.


Assuntos
Proteínas de Transporte/metabolismo , Proteínas de Plasma Seminal/metabolismo , Motilidade dos Espermatozoides , Cauda do Espermatozoide/metabolismo , Animais , Proteínas de Transporte/genética , AMP Cíclico/metabolismo , Deleção de Genes , Regulação da Expressão Gênica , Infertilidade Masculina/genética , Masculino , Glicoproteínas de Membrana/metabolismo , Camundongos , Camundongos Knockout , Microscopia Eletrônica de Varredura , Microscopia de Contraste de Fase , Mutação , Ligante RANK , Receptor Ativador de Fator Nuclear kappa-B , Proteínas de Plasma Seminal/genética , Cauda do Espermatozoide/ultraestrutura , Tubulina (Proteína)/metabolismo
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