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BACKGROUND: The association between obesity and some cardiovascular complications such as heart failure (HF) is well established, and drugs affecting adiposity are supposed to be promising treatments for these conditions. The sodium-glucose cotransporter-2 inhibitors (SGLT2i) are antidiabetic drugs showing benefits in patients with HF, despite the underlying mechanisms have not been completely understood yet. SGLT2i are supposed to promote systemic effects, such as triglycerides mobilization, through the enhancement of fibroblast growth factor-21 (FGF-21) activity. So, in this study, we evaluated the effects of dapagliflozin treatment on FGF-21 and related receptors (FGF-Rs) gene expression and on lipid content in myocardial tissue in an animal model of genetically induced obesity to unravel possible metabolic mechanisms accounting for the cardioprotection of SGLT2i. METHODS: Six-week-old C57BL/6J wild-type mice and B6.V-LEP (ob/ob) mice were randomly assigned to the control or treatment group (14 animals/group). Treatment was based on the administration of dapagliflozin 0.15 mg/kg/day for 4 weeks. The gene expression of FGF-21 and related receptors (FGF-R1, FGF-R3, FGF-R4, and ß-klotho co-receptor) was assessed at baseline and after treatment by real-time PCR. Similarly, cardiac triglycerides concentration was measured in the control group and treated animals. RESULTS: At baseline, FGF-21 mRNA expression in the heart did not differ between lean and obese ob/ob mice. Dapagliflozin administration significantly increased heart FGF-21 gene expression, but only in ob/ob mice (p < 0.005). Consistently, when measuring the amount of triglycerides in the cardiac tissue, SGLT2i treatment reduced the lipid content in obese ob/ob mice, while no significant effects were observed in treated lean animals (p < 0.001). The overall expression of the FGF-21 receptors was only minimally affected by dapagliflozin treatment both in obese ob/ob mice and in lean controls. CONCLUSIONS: Dapagliflozin administration increases FGF-21gene expression and reduces triglyceride content in myocardial tissue of ob/ob mice, while no significant effect was observed in lean controls. These results might help understand the cardiometabolic effects of SGLT2i inducing increased FGF-21 synthesis while reducing lipid content in cardiomyocytes as a possible expression of the switch to different energy substrates. This mechanism could represent a potential target of SGLT2i in obesity-related heart diseases.
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Compostos Benzidrílicos , Fatores de Crescimento de Fibroblastos , Glucosídeos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Miocárdio , Obesidade , Triglicerídeos , Animais , Glucosídeos/farmacologia , Fatores de Crescimento de Fibroblastos/metabolismo , Fatores de Crescimento de Fibroblastos/genética , Camundongos , Compostos Benzidrílicos/farmacologia , Triglicerídeos/metabolismo , Miocárdio/metabolismo , Obesidade/metabolismo , Obesidade/tratamento farmacológico , Inibidores do Transportador 2 de Sódio-Glicose/farmacologia , MasculinoRESUMO
PURPOSE: The contribution of endothelial-targeted autoantibodies against the angiotensin II type 1 receptor (anti-AT1R) and the anti-endothelin 1 type A receptor (anti-ETAR1) has been proposed in the development of cardiovascular diseases. However, no data have been reported yet in obesity. In this observational study we evaluated the relationship between anthropometric and metabolic parameters and anti-AT1R and anti-ETAR1 concentrations in a cohort of patients with severe obesity and associated comorbidities undergoing bariatric surgery. METHODS: Clinical evaluation and metabolic assessment were performed in 36 subjects referring to our Center for the Study and Integrated Treatment of Obesity at the University Hospital of Padova. Circulating inflammatory adipocytokines and the endothelial dysfunction marker asymmetric dimethylarginine (ADMA) were evaluated; plasma levels of anti-AT1R and anti-ETAR1 were also determined. 10 normal-weight subjects were considered as a control group. 29 patients out of 36 were re-evaluated after surgery. RESULTS: With respect to normal-weight controls patients showed significantly higher plasma levels of anti-AT1R (28 ± 20.4 vs 13.5 ± 2.8 U/mL, p < 0.005) and ADMA (0.8 ± 0.1 vs 0.54 ± 0.08 uM/L, p < 0.0001) but not anti-ETAR1 (14.2 ± 1.3 vs 13.3 ± 2 U/mL, p = 0.1). Anti-AT1R concentration showed an increasing trend with the worsening of glycemic status, while the presence of arterial hypertension among the patients did not affect autoantibodies levels. One year after surgery, a significant improvement in body weight and metabolic and inflammatory parameters was observed, along with a significant reduction of anti-AT1R (28.1 ± 20.4 U/mL vs 22.6 ± 16 U/mL, p < 0.05) and anti-ETAR1 (14.2 ± 1.3 U/L vs 13 ± 1.6 U/L, p < 0.01). CONCLUSIONS: Subjects with obesity present higher plasma levels of anti-AT1R which are more related to glycemic profile than blood pressure levels, and are reduced by bariatric surgery. Considering the detrimental effects of these autoantibodies on vascular health, they should be assessed as potential biomarkers in obesity and metabolic diseases.
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INTRODUCTION: Vitamin D is involved in the regulatory mechanisms of ovarian function and is frequently low in PCOS patients. Since obesity and hyperinsulinemic state negatively influenced vitamin D levels, therefore, we evaluated the production of vitamin D at the ovarian level only in lean and normoinsulinemic PCOS subjects. Basal, GnRH analogue-induced ovarian production of 25OH-vitamin D (VitD) and a direct sampling at ovarian vein level were investigated. METHODS: Basal and GnRH analogue-induced hormone levels were evaluated at peripheral level in 45 subjects, aged 18-39 years, and in 22 healthy women with age- and BMI-matched as controls. In 12 PCOS patients, undergoing laparoscopy, a venous sampling at both peripheral and ovarian level was further done. All subjects presented low VitD levels, appropriate to the season and with no difference between PCOS and control subjects. RESULTS: GnRH analogue significantly stimulated plasma LH, FSH, 17-OHP and estradiol secretion (p from < 0.05 to < 0.001 vs basal levels), whereas no effect was observed on both serum AMH and VitD concentrations in all groups. A significant difference (p < 0.006), between peripheral and ovarian veins, was observed in both AMH and estradiol levels in PCOS subjects, while no gradient of VitD was detected. CONCLUSIONS: All patients presented with low VitD levels. The absence of any VitD variation, both at basal and after GnRH analogue administration, or at peripheral-ovarian vein gradient, suggests no pituitary-ovarian axis involvement in VitD production or its direct ovarian production in lean and normoinsulinemic PCOS subjects.
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Hidroxicolecalciferóis/metabolismo , Ovário/metabolismo , Síndrome do Ovário Policístico/metabolismo , Adolescente , Adulto , Coleta de Amostras Sanguíneas , Estudos de Casos e Controles , Feminino , Hormônio Foliculoestimulante/sangue , Humanos , Hormônio Luteinizante/sangue , Ovário/irrigação sanguínea , Ovário/patologia , Síndrome do Ovário Policístico/patologia , Vitamina D/sangue , Adulto JovemRESUMO
We report the case of a 15-year-old woman with signs of hyperandrogenism affected by a Sertoli-Leydig cell tumor (SLCT). In our patient, blood analysis showed a high testosterone (T) level (T: 8.53 nmol/L; nv < 1.87 nmol/L) while the GnRH-analogue test demonstrated an exaggerated secretion of 17-hydroxyprogesterone (OHP), T, and androstenedione (A) by the ovary after stimulation. We compared the GnRH-analogue test of our patient with that obtained in a group of normal and healthy women (no. 8 subjects, 16-26 years old), men (no. 4 subjects, 18-28 years old), and in a group of PCOS patients with age and body weight compared. We found in our patient a value of OHP, 17-beta estradiol (E2) and T, from 2 to 18 times higher than healthy women. When we compared our patient with healthy men, we differently observed a comparable response of T. The response of our patient was also comparable with that observed in the PCOS group for E2. During the post-surgical follow up, the GnRH-analogue test of our patient showed a response of OHP, T, and E2 comparable with that of the PCOS group. The GnRH-analogue test is a useful tool to characterize steroidogenesis in SLCT.
Assuntos
Hiperandrogenismo/diagnóstico , Neoplasias Ovarianas/complicações , Tumor de Células de Sertoli-Leydig/complicações , Pamoato de Triptorrelina , Adolescente , Estradiol/sangue , Feminino , Hormônio Foliculoestimulante/sangue , Humanos , Hiperandrogenismo/sangue , Hiperandrogenismo/etiologia , Hiperandrogenismo/patologia , Hormônio Luteinizante/sangue , Neoplasias Ovarianas/sangue , Neoplasias Ovarianas/patologia , Tumor de Células de Sertoli-Leydig/sangue , Tumor de Células de Sertoli-Leydig/patologia , Testosterona/sangueRESUMO
AIMS/HYPOTHESIS: Visceral and intermuscular adipose tissue (IMAT) depots account for most obesity-related metabolic and cardiovascular complications. Muscle satellite cells (SCs) are mesenchymal stem cells giving rise to myotubes and also to adipocytes, suggesting their possible contribution to IMAT origin and expansion. We investigated the myogenic differentiation of SCs and the adipogenic potential of both preadipocytes and SCs from genetically obese Zucker rats (fa/fa), focusing on the role of Wnt signaling in these differentiation processes. METHODS: SCs were isolated by single-fiber technique from flexor digitorum brevis muscle and preadipocytes were extracted from subcutaneous adipose tissue (AT). Morphological features and gene expression profile were evaluated during in vitro myogenesis and adipogenesis. Wingless-type MMTV integration site family member 10b (Wnt10b) expression was quantified by quantitative PCR in skeletal muscle and AT. RESULTS: We did not observe any difference in the proliferation rate and in the myogenic differentiation of SCs from obese and lean rats. However, a decreased insulin-induced glucose uptake was present in myotubes originating from fa/fa rats. Under adipogenic conditions, preadipocytes and SCs of obese animals displayed an enhanced adipogenesis. Wnt10b expression was reduced in obese rats in both muscle and AT. CONCLUSIONS/INTERPRETATION: Our data suggest that the increase in different fat depots including IMAT and the reduced muscle insulin sensitivity, the major phenotypical alteration of obese Zucker rats, could be ascribed to an intrinsic defect, either genetically determined or acquired, still present in both muscle and fat precursors. The involvement of Wnt10b as a regulator of both adipogenesis and muscle-to-fat conversion is suggested.
Assuntos
Adipogenia/fisiologia , Tecido Adiposo/metabolismo , Resistência à Insulina/fisiologia , Obesidade/metabolismo , Células Satélites de Músculo Esquelético/citologia , Adipogenia/genética , Animais , Diferenciação Celular/fisiologia , Resistência à Insulina/genética , Masculino , Obesidade/genética , Ratos , Ratos Zucker , Células Satélites de Músculo Esquelético/metabolismoRESUMO
The generation of regulatory T cells (Tregs) in vitro represents an attractive possibility to set up cellular therapies that could prevent and cure autoimmune disorders. Different methods have been proposed to generate Tregs in vitro and to evaluate their phenotype and function. Moreover, the overlap between generation of activated and regulatory cells could often be underestimated. We showed that in vitro treatment of CD4+ CD25- lymphocytes with different stimuli leads to a good expression of CD25 and forkhead box P3 (FoxP3) on most cells, but to a full Treg phenotype (including CD127 negativity) in only a minor percentage of cells, ranging from 17.38% of cells treated with phytohaemagglutinin (PHA) to 50.91% of cells treated with T cell receptor (TCR) stimulation in association with transforming growth factor (TGF)-beta. Some suppressive activity was demonstrated for T cells activated with all the different stimuli. However, while suppression mediated by TCR/TGF-beta treated T cells was associated with an inhibition of both interleukin (IL)-2 and interferon (IFN)-gamma in the co-culture supernatant, the suppression observed for PHA-activated cells occurred in the presence of large amounts of these cytokines. In conclusion, also taking into account other recent publications, caution should be taken in interpretation of data in the field of regulatory T cells.
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Linfócitos T CD4-Positivos/imunologia , Tolerância Imunológica/imunologia , Ativação Linfocitária/imunologia , Proliferação de Células , Células Cultivadas , Fatores de Transcrição Forkhead/metabolismo , Humanos , Imunofenotipagem , Interferon gama/biossíntese , Interleucina-2/biossíntese , Subunidade alfa de Receptor de Interleucina-2/metabolismo , Fito-Hemaglutininas/imunologia , Linfócitos T Reguladores/imunologiaRESUMO
The preferential channeling of different fuels to fat and changes in the transcription profile of adipose tissue and skeletal muscle are poorly understood processes involved in the pathogenesis of obesity and insulin resistance. Carbohydrate and lipid metabolism may play relevant roles in this context. Freely moving lean Zucker rats received 3- and 24-h infusions of Intralipid (Pharmacia and Upjohn, Milan, Italy) plus heparin, or saline plus heparin, to evaluate how an increase in free fatty acids (nonesterified fatty acid [NEFA]) modulates fat tissue and skeletal muscle gene expression and thus influences fuel partitioning. Glucose uptake was determined in various tissues at the end of the infusion period by means of the 2-deoxy-[1-3H]-D-glucose technique after a euglycemic-hyperinsulinemic clamp: high NEFA levels markedly decreased insulin-mediated glucose uptake in red fiber-type muscles but enhanced glucose utilization in visceral fat. Using reverse transcriptase-polymerase chain reaction and Northern blotting analyses, the mRNA expression of fatty acid translocase (FAT)/CD36, GLUT4, tumor necrosis factor (TNF)-alpha, peroxisome proliferator-activated receptor (PPAR)-gamma, leptin, uncoupling protein (UCP)-2, and UCP-3 was investigated in different fat depots and skeletal muscles before and after the study infusions. GLUT4 mRNA levels significantly decreased (by approximately 25%) in red fiber-type muscle (soleus) and increased (by approximately 45%) in visceral adipose tissue. Furthermore, there were marked increases in FAT/CD36, TNF-alpha, PPAR-gamma, leptin, UCP2, and UCP3 mRNA levels in the visceral fat and muscle of the treated animals in comparison with those measured in the saline-treated animals. These data suggest that the in vivo gene expression of FAT/CD36, GLUT4, TNF-alpha, PPAR-gamma, leptin, UCP2, and UCP3 in visceral fat and red fiber-type muscle are differently regulated by circulating lipids and that selective insulin resistance seems to favor, at least in part, a prevention of fat accumulation in tissues not primarily destined for fat storage, thus contributing to increased adiposity and the development of a prediabetic syndrome.
Assuntos
Tecido Adiposo/metabolismo , Metabolismo Energético , Ácidos Graxos não Esterificados/farmacocinética , Músculo Esquelético/metabolismo , Tecido Adiposo/fisiologia , Animais , Emulsões Gordurosas Intravenosas/farmacocinética , Emulsões Gordurosas Intravenosas/farmacologia , Expressão Gênica/efeitos dos fármacos , Técnica Clamp de Glucose , Heparina/farmacologia , Masculino , Fibras Musculares Esqueléticas/fisiologia , Músculo Esquelético/fisiologia , Ratos , Ratos Zucker , VíscerasRESUMO
A reduced lipid oxidative capacity is considered a risk factor for the development of obesity, but a further impairment of lipid oxidative capacity is observed after weight loss. We aimed to define the mechanisms underlying this phenomenon in skeletal muscle and in particular to study the mitochondrial and peroxisomal lipid oxidative pathways. Thus we measured intramyocellular triglyceride content (IMTG) and the expression of genes of lipid oxidation [peroxisome proliferator-activated receptor-alpha, carnitine palmitoyltransferase 1B, and acyl-coenzyme A (acyl-CoA) oxidase 1] and synthesis (acetyl-CoA carboxylase B) using RT-PCR analysis in muscle biopsies of morbidly obese patients before and after biliopancreatic diversion. Weight reduction significantly decreased IMTG while increasing insulin sensitivity, measured by euglycemic hyperinsulinemic clamp. Moreover, an increase in glucose and a decline in lipid oxidation, as assessed by respiratory chamber, were observed. Weight loss reduced the expression of peroxisome proliferator-activated receptor-alpha (-46.7%), carnitine palmitoyltransferase 1B (-43.1%), acyl-CoA oxidase 1 (-37.8%), and acetyl-CoA carboxylase B (-48.7%). Our results indicate that a defect of both peroxisomal and mitochondrial oxidative pathways at the muscular level may contribute to the reduced fat oxidation in obese subjects after biliopancreatic diversion. They also suggest that a depression of the de novo lipogenesis may account for IMTG depletion.
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Desvio Biliopancreático , Metabolismo dos Lipídeos , Músculo Esquelético/metabolismo , Obesidade Mórbida/metabolismo , Obesidade Mórbida/cirurgia , Expressão Gênica , Técnica Clamp de Glucose , Glicerídeos/metabolismo , Humanos , Resistência à Insulina , Células Musculares/metabolismo , Obesidade Mórbida/fisiopatologia , Oxirredução , Peroxissomos/metabolismo , Redução de PesoRESUMO
Myostatin is a member of transforming growth factor-beta superfamily that plays an important inhibitory role during muscle development; in fact mutations of myostatin gene result in a hypermuscular phenotype. Moreover myostatin-deficient mice have a significant reduction in fat depots and a depression of adipogenesis. Little is known about myostatin function in muscle growth regulation in humans and in particular during caloric restriction. In the present work we quantified by real-time RT-PCR myostatin expression in muscle biopsies of a group of morbidly obese patients before and after weight loss obtained by biliopancreatic diversion (BPD). The patients reduced body weight by 38.9%, mostly due to fat-mass loss, showing also a significant reduction in the 24-hour EE as assessed by the respiratory chamber. Myostatin mRNA levels result clearly decreased after weight loss, suggesting a role in counteracting the progressive decline of muscle mass after BPD. Myostatin may provide therefore another mechanistic explanation for the control of energy partitioning between protein and fat, working against muscle wasting. Our data suggest that myostatin might represent an important regulator of skeletal muscle size also in conditions of food restriction in obese subjects.
Assuntos
Músculo Esquelético/fisiologia , Obesidade/fisiopatologia , Fator de Crescimento Transformador beta/genética , Redução de Peso/fisiologia , Composição Corporal , Dieta Redutora , Metabolismo Energético/fisiologia , Expressão Gênica/fisiologia , Humanos , Miostatina , Nitrogênio/urina , Obesidade/dietoterapia , Fator de Crescimento Transformador beta/metabolismoRESUMO
P-glycoprotein (P-gp) and multidrug resistance related protein (MRP) overexpression is often responsible of the development of multidrug resistance in cancer therapy. These proteins are also expressed in normal tissues, where their physiological role is related to the extrusion of endogenous toxins or to secretory function in liver and kidney. The LLC-PK1 cell line is derived from normal pig proximal renal tubule and physiologically expresses low levels of P-gp and MRP. A resistant cell line (LLC-PK1/ADR) has been established in our laboratory by chronic exposure to increasing doses of doxorubicin. Cytofluorimetric analysis of P-gp and MRP expression performed by C219 and MRPm6 immunofluorescence detection showed that these cells overexpress P-gp but not MRP. The uptake of doxorubicin and rhodamine 123 has been quantified in LLC-PK1 and LLC-PK1/ADR cells and compared with data obtained using other tumor cell lines commonly used as reference for studying P-gp or MRP overexpression. P388 sensitive cells and its resistant counterpart P388/ADR cells, which overexpress P-gp and PANC-1 cells, which express high levels of MRP were used. A lower fluorescence intensity was evident with both doxorubicin and rhodamine 123 in LLC-PK1/ADR as well as in P388/ADR cells, that overexpresses P-gp, in comparison with the parental lines. The uptake was increased by a pretreatment with verapamil. Verapamil was completely ineffective on PANC-1 cells, confirming a selective effect of this inhibitor on P-gp. Propidium iodide staining, performed after doxorubicin treatment, confirmed a higher cytotoxicity of the antineoplastic drug in the LLC-PK1 cells compared with the resistant counterpart.
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Membro 1 da Subfamília B de Cassetes de Ligação de ATP/biossíntese , Transportadores de Cassetes de Ligação de ATP/biossíntese , Resistência a Múltiplos Medicamentos/fisiologia , Células LLC-PK1/efeitos dos fármacos , Células LLC-PK1/metabolismo , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/imunologia , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Transportadores de Cassetes de Ligação de ATP/imunologia , Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Antibióticos Antineoplásicos/farmacocinética , Antibióticos Antineoplásicos/toxicidade , Anticorpos Monoclonais , Linhagem Celular , Corantes , Doxorrubicina/farmacocinética , Doxorrubicina/toxicidade , Resistencia a Medicamentos Antineoplásicos , Epitopos/imunologia , Citometria de Fluxo , Corantes Fluorescentes/farmacocinética , Humanos , Túbulos Renais/efeitos dos fármacos , Túbulos Renais/metabolismo , Leucemia P388/tratamento farmacológico , Leucemia P388/metabolismo , Camundongos , Proteínas Associadas à Resistência a Múltiplos Medicamentos , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/metabolismo , Propídio , Rodamina 123/farmacocinética , Coloração e Rotulagem/métodos , Suínos , Células Tumorais CultivadasRESUMO
The relative bioavailability of the major alkamides, dodeca-2E,4E,8Z,10E/Z-tetraenoic acid isobutylamides, from Echinacea purpurea phytotherapeutic lozenges at three different dose levels (0.07, 0.21 and 0.9 mg) was evaluated in a pharmacokinetic study in humans and the possible effects on the immunological system were measured. Alkamides were found to be rapidly absorbed and measurable in plasma 10 min after administration of 0.21 and 0.9 mg lozenges and remained detectable for 3h for the 0.21 mg lozenges and for more then 3h for the 0.9 mg lozenges; 0.07 mg lozenges were measurable 20 min after administration and remained detectable for only 2h after the administration. A significant dose-independent down-regulation of the pro-inflammatory cytokines IL-12p70, IL-8, IL-6, IL-10 and TNF was observed 24h after oral administration. The results of non-compartmental pharmacokinetic analysis revealed that a C(max) of (0.65+/-0.41 ng/ml) was reached at 32 min with the 0.07 mg lozenges, (1.00+/-0.21ng/ml) at 25 min with the 0.21 mg lozenges and (8.88+/-5.89 ng/ml) at 19 with the 0.9mg lozenges. As evidenced by the dose-exposure relationship, no significant departure from dose proportionality was observed, indicating linearity in pharmacokinetics. To get a further insight in pharmacokinetics of dodeca-2E,4E,8Z,10E/Z-tetraenoic isobutylamides a compartmental population pharmacokinetic model was developed applying mixed effect modelling procedure. The results demonstrate that within the dose range studied pharmacokinetics of dodeca-2E,4E,8Z,10E/Z-tetraenoic isobutylamides are linear and that absorption is very rapid (t(1/2)=6 min) with apparently no lag time, thus indicating the possibility that a fraction of the drug is absorbed through the oral mucosa.
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Echinacea/química , Ácidos Graxos Insaturados/farmacologia , Ácidos Graxos Insaturados/farmacocinética , Extratos Vegetais/farmacologia , Extratos Vegetais/farmacocinética , Alcamidas Poli-Insaturadas/farmacologia , Alcamidas Poli-Insaturadas/farmacocinética , Adjuvantes Imunológicos/administração & dosagem , Adjuvantes Imunológicos/sangue , Adjuvantes Imunológicos/farmacocinética , Adjuvantes Imunológicos/farmacologia , Área Sob a Curva , Citocinas/sangue , Formas de Dosagem , Relação Dose-Resposta a Droga , Ácidos Graxos Insaturados/administração & dosagem , Ácidos Graxos Insaturados/sangue , Feminino , Meia-Vida , Humanos , Masculino , Fitoterapia , Extratos Vegetais/administração & dosagem , Extratos Vegetais/sangue , Alcamidas Poli-Insaturadas/administração & dosagem , Alcamidas Poli-Insaturadas/sangueRESUMO
BACKGROUND: The objectives of this study were (i) to evaluate whether the combined use of Syto 16 and 7-amino-actinomycin-D (7-AAD) allows the detection of sperm apoptosis and (ii) to describe a new multiparameter flow cytometric method to assess simultaneously sperm concentration (SC), viability and apoptosis as well as leukocyte concentration. METHODS: Semen samples from 68 patients were evaluated according to World Health Organization (WHO) criteria (normal, n=26; abnormal, n=42). The detection of activated caspases before and after betulinic acid (BA) incubation was carried out in 13 semen samples by flow cytometry using fluorescein-labelled inhibitors of caspases (FLICA). A multiparameter flow cytometric analysis was performed in 55 semen samples. Fluorescent microspheres were used to assess SC. Sperm apoptosis was detected by staining sperm with Syto 16 and 7-AAD. Leukocytes were counted using monoclonal anti-CD45. RESULTS: A significant correlation between the percentage of the spermatozoa with low Syto 16 fluorescence and the percentage of spermatozoa containing activated caspases was found (r=0.68, P=0.0106; n=13). After incubation with BA, an increase of the percentage of apoptotic cells was observed in all samples, using both the Syto 16/7-AAD and the caspase activation methods. There was a good correlation between flow cytometry and optical microscopy for sperm (r=0.98, P < 0.0001) and leukocyte counting (r=0.64, P <0.0001). The percentage of apoptotic sperm was inversely correlated with both SC (r=-0.303, P=0.0246) and morphology (r=-0.384, P=0.0050) but not with motility. CONCLUSIONS: The combination of Syto 16/7-AAD provides a sensitive assay to detect sperm apoptosis. The multiparameter flow cytometric method described offers the possibility of a simultaneous, simple, rapid and accurate assessment of several semen parameters.
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Apoptose/efeitos dos fármacos , Citometria de Fluxo/métodos , Sêmen/citologia , Sêmen/fisiologia , Adulto , Caspases/metabolismo , Dactinomicina/análogos & derivados , Ativação Enzimática , Corantes Fluorescentes , Humanos , Antígenos Comuns de Leucócito/imunologia , Leucócitos/citologia , Masculino , Necrose , Triterpenos Pentacíclicos , Reprodutibilidade dos Testes , Espermatozoides/efeitos dos fármacos , Triterpenos/farmacologia , Ácido BetulínicoRESUMO
AIMS/HYPOTHESIS: Recent studies suggest that wingless-type MMTV integration site family, member 10B (WNT10B) may play a role in the negative regulation of adipocyte differentiation in vitro and in vivo. In order to determine whether mutations in WNT10B contribute to human obesity, we screened two independent populations of obese subjects for mutations in this gene. SUBJECTS AND METHODS: We studied 96 subjects with severe obesity of early onset (less than 10 years of age) from the UK Genetics of Obesity Study and 115 obese Italian subjects of European origin. RESULTS: One proband with early-onset obesity was found to be heterozygous for a C256Y mutation, which abrogated the ability of WNT10B to activate canonical WNT signalling and block adipogenesis and was not found in 600 control alleles. All relatives of the proband who carried this allele were either overweight or obese. Three other rare missense variants were found in obese probands, but these did not clearly cosegregate with obesity in family studies and one (P301S), which was found in three unrelated subjects with early-onset obesity, had normal functional properties. CONCLUSIONS/INTERPRETATION: These mutations represent the first naturally occurring missense variants of WNT10B. While the pedigree analysis in the case of C256Y WNT10B does not provide definitive proof of a causal link of this variant with obesity, the finding of a non-functioning WNT10B allele in a human family affected by obesity should encourage further study of this gene in other obese populations.
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Mutação/genética , Obesidade/genética , Proteínas Proto-Oncogênicas/genética , Proteínas Wnt/genética , Adipócitos/citologia , Adipócitos/metabolismo , Adulto , Sequência de Aminoácidos , Animais , Diferenciação Celular/genética , Linhagem Celular , Sequência Conservada , Cisteína/genética , Cisteína/metabolismo , Análise Mutacional de DNA , Feminino , Humanos , Masculino , Camundongos , Dados de Sequência Molecular , Linhagem , Prolina/genética , Prolina/metabolismo , Proteínas Proto-Oncogênicas/química , Proteínas Proto-Oncogênicas/metabolismo , Alinhamento de Sequência , Transdução de Sinais , Proteínas Wnt/química , Proteínas Wnt/metabolismoRESUMO
Melatonin has been reported to attenuate the oxidative damage caused by doxorubicin on kidney, brain, heart and bone marrow, whereas the in vivo antitumor effects of doxorubicin were not attenuated. The effects of melatonin on doxorubicin cytotoxicity have, therefore, been examined on human normal mammary epithelium HBL-100, on mammary adenocarcinoma MCF-7, on colon carcinoma LoVo, and on mouse P388 leukemia cell lines, and on tumor cell sublines pleiotropically resistant to anthracyclines. Melatonin in the concentration range 10-2000 pg/mL causes an inhibition of the growth of the human cell lines examined which is not clearly dose-dependent and less than 25% when significant. Melatonin similarly causes minor effects on doxorubicin cytotoxicity either on the parental human cell lines or on their resistant sublines. On the contrary, 200-1000 pg/mL melatonin cause a significant and dose-dependent partial sensitization to doxorubicin of resistant P388 mouse leukemia (P388/ADR), which occurs also in vivo, as indicated by a significant increase in survival time of the hosts. Doxorubicin intracellular concentrations in P388/ADR cells are increased by melatonin, suggesting that melatonin might inhibit P-glycoprotein-mediated doxorubicin efflux from the cells. These results indicate that the use of melatonin in clinical cancer treatment should not pose the risk of an attenuation of the effectiveness of doxorubicin, and encourage the further examination of the possible reduction by melatonin of the host toxicity of antitumor chemotherapy.
Assuntos
Antineoplásicos/toxicidade , Antioxidantes/farmacologia , Doxorrubicina/toxicidade , Resistencia a Medicamentos Antineoplásicos , Sequestradores de Radicais Livres/farmacologia , Melatonina/farmacologia , Células Tumorais Cultivadas/efeitos dos fármacos , Animais , Divisão Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Resistência a Múltiplos Medicamentos , Células Epiteliais/efeitos dos fármacos , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Células Tumorais Cultivadas/patologiaRESUMO
AIM: The tissue-Trans-Glutaminase (t-TG) has been reported to be the target for endomysial antibodies in coeliac disease. Coeliac disease if untreated, although clinically silent, predispose for other autoimmune disease, large scale screening methods are needed for an early diagnosis. The recently introduced ELISA methods to detect tTG antibodies, that used as antigen Guinea Pig tissue transglutaminase provide an efficient alternative to the anti-endomysial (EMA) immunofluorescent method and are suitable for screening. Our aim was to compare the commercial kit utilizing tTG from guinea pig (GP-tTG) to the standard method that we developed in our laboratory and with the new method that employed human recombinant tTG (hr-tTG). METHODS: We tested serum samples from 16 untreated celiac patients, 10 coeliac patients in gluten free diet, 22 subjects with other disease and 32 healthy controls, for a total number of 80 sera, with 3 commercial kit which employed GP-tTG and 1 that employed hr-tTG, as reference method we used an ELISA method developed in our laboratory and the immunofluorescence method to detect EMA. RESULTS: Results show that methods employing human tTG had a sensibility of 100% with a specificity of 98% and a predictive value of 94%, instead methods employing GP-tTG show inferior results. CONCLUSION. We conclude that is better using hr-tTG as antigen in screening methods for coeliac disease.
Assuntos
Autoanticorpos/sangue , Doença Celíaca/sangue , Doença Celíaca/diagnóstico , Kit de Reagentes para Diagnóstico , Proteínas Recombinantes/imunologia , Transglutaminases/imunologia , Adolescente , Adulto , Animais , Criança , Pré-Escolar , Cobaias , Humanos , Lactente , Sensibilidade e EspecificidadeRESUMO
The genotoxic activities of 8-methoxypsoralen (8-MOP) and 4,4',5'-trimethylazapsoralen (4,4',5'-TMAP) on plasmid DNA have been compared. In a previous work, 4,4',5'-TMAP, a methyl derivative of a psoralen isoster, had shown potential photochemotherapeutic activity. The mutagenic activity of mono- and bifunctional lesions caused by these compounds was evaluated both after UVA irradiation, which causes the formation of both kinds of lesions, and after a two-step irradiation procedure of the psoralen-plasmid DNA complex, which allowed monoadducts and interstrand crosslinks to be studied separately. Furthermore, we used a procedure that allowed us to evaluate both the mutagenic and recombinogenic activity of the two compounds. Results indicate that the most important difference between 8-MOP and 4,4',5'-TMAP consists in their mode of photoreaction with DNA rather than in their mutagenic potential. In fact, in all of the experimental procedures, 4,4',5'-TMAP shows a lower ability than 8-MOP to generate interstrand crosslinks. However, when comparable toxicity levels are reached, the two compounds show the same mutagenic potentiality.
Assuntos
DNA/efeitos dos fármacos , Furocumarinas/toxicidade , Plasmídeos , Metoxaleno/toxicidade , Mutação , Raios UltravioletaRESUMO
Mechanisms of regulation of plasma leptin in lean and genetically obese animals are not completely understood. In particular a relation has been proposed between energy metabolism and leptin. However, it is not clear how energy expenditure and leptin are related under exercise in lean and obese animals. To clarify these aspects we investigated lean and genetically obese (fa/fa) Zucker rats undergoing a single bout (30 min) of swimming and measured several biochemical and hormonal parameters of energy metabolism and leptin changes throughout the study. Moreover ob-gene expression in adipose tissue was also measured. Our results showed that plasma leptin is decreased by 30% at the end of exercise in lean animals while resulting unaffected in obese animals. Leptin changes in lean rats are concomitant with the peak of NEFA and glycerol release from adipose tissue rather than with the reduction of plasma insulin. Ob-gene expression in adipose tissue was markedly increased in fa/fa compared to lean rats, but was not modified by exercise both in lean and obese animals. In conclusion our data show that leptin changes during exercise are related to lipolytic events in adipose tissue and support a link between leptin and energy expenditure.
Assuntos
Obesidade/genética , Esforço Físico , Proteínas/metabolismo , Tecido Adiposo/metabolismo , Animais , Glicemia/metabolismo , Ácidos Graxos não Esterificados/sangue , Feminino , Glicerol/sangue , Insulina/sangue , Ácido Láctico/sangue , Leptina , RNA Mensageiro/análise , Ratos , Ratos Zucker , NataçãoRESUMO
To clarify the function of the multidrug transporter P-glycoprotein in mast cells we used the green fluorescent compound Bodipy-FL-verapamil, which is a substrate of P-glycoprotein. This compound is also transported by Multidrug Resistance-related Protein (MRP), another membrane transport protein expressed in many tumour resistant cells as well as in normal cells. When rat peritoneal mast cells were incubated with Bodipy-verapamil, a rapid uptake of this compound was observed. Pretreatment with modulators of P-glycoprotein activity, such as verapamil and vinblastine, increased Bodipy-verapamil intracellular concentrations. In addition, Bodipy-verapamil efflux from these cells was rapid and also inhibited by verapamil and vinblastine. In contrast, no effect was observed when cells were treated with agents, such as probenecid and indomethacin, that are known inhibitors of MRP. Methylamine and monensin, substances that modify the pH values in the granules, were able to lower the concentrations of Bodipy-verapamil. Microscopical observations, conducted in both rat and beige mouse mast cells, demonstrated that the fluorochrome accumulated in the cytoplasmic secretory granules. RT-PCR performed on rat peritoneal mast cells revealed the presence of MDR1a and MDR1b mRNAs; on the contrary, MRP mRNA was not expressed. Mast cells were further treated with the fluorescent probe LysoSensor Blue, a weak base that becomes fluorescent when inside acidic organelles. This substance accumulated in mast cell granular structures and its fluorescence was reduced either by treatment with P-glycoprotein modulators or with agents that disrupt pH gradients. In conclusion, these data further confirm the presence of an active P-glycoprotein, but not of MRP, in rat peritoneal mast cells. These findings, coupled with previous ultrastructural data, lend further support to the assumption that this protein is located on the mast cell perigranular membrane. The functional role of P-glycoprotein in these cells is at present unclear, but a possible involvement in the transport of molecules from the granules to the cytosol can be hypothesized. Alternatively, this protein might be indirectly implicated in changes of pH values inside secretory granules.
Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Resistência a Múltiplos Medicamentos/fisiologia , Mastócitos/metabolismo , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Verapamil/análogos & derivados , Verapamil/metabolismo , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Animais , Antineoplásicos Fitogênicos/farmacologia , Bloqueadores dos Canais de Cálcio/farmacologia , Corantes Fluorescentes/metabolismo , Indicadores e Reagentes/metabolismo , Ionóforos/farmacologia , Mastócitos/citologia , Mastócitos/efeitos dos fármacos , Metilaminas/farmacologia , Camundongos , Camundongos Endogâmicos , Microscopia de Fluorescência , Monensin/farmacologia , Proteínas Associadas à Resistência a Múltiplos Medicamentos/antagonistas & inibidores , Peritônio/citologia , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Vesículas Secretórias/química , Vesículas Secretórias/metabolismo , Espectrometria de Fluorescência , Verapamil/farmacologia , Vimblastina/farmacologiaRESUMO
OBJECTIVES: To evaluate the plasma leptin concentration in lean and genetically obese fa/fa rats and to assess the response to 2 h hyperinsulinaemia. BACKGROUND: The recently discovered peptide leptin is a putative link between the size of the adipose mass and the hypothalamic centres controlling feeding behaviour. Several genetic models of animal obesity have been characterized as carriers of mutations of either the ob gene or leptin receptor. EXPERIMENTAL DESIGN: Lean (+/?) and obese (fa/fa) Zucker rats were studied under pentobarbital anaesthesia and underwent a 2 h euglycaemic hyperinsulinaemic clamp. Plasma leptin was measured in basal condition and at the end of the clamp study. Glucose rate of disappearance was evaluated by means of the isotope dilution technique using 3-3H-glucose as tracer. RESULTS: fa/fa rats showed a 40 fold higher leptin concentration compared to lean littermates (0.47 +/- 0.10 vs 19.55 +/- 1.50 ng/ml, P < 0.0001). Euglycaemic hyperinsulinaemia increased plasma leptin in lean but not in genetically obese rats. CONCLUSIONS: Our results suggest that insulin may be a regulator of in vivo leptin secretion by adipose tissue of lean rates whereas it is ineffective in increasing plasma leptin in obese Zucker rats.
Assuntos
Hiperinsulinismo/metabolismo , Insulina/farmacologia , Obesidade/metabolismo , Proteínas/efeitos dos fármacos , Animais , Glicemia , Técnica Clamp de Glucose , Leptina , Masculino , Obesidade/genética , Proteínas/metabolismo , Ratos , Ratos ZuckerRESUMO
Both hyperglycemia and hyperinsulinemia stimulate whole body and muscle glucose disposal. To define the impact of increased lactate concentration (4-5 mM) on muscle glucose disposal during hyperglycemia, we studied anesthetized normal rats infused with either sodium lactate or sodium bicarbonate as control. Animals were studied under hyperglycemic clamp (13 mM) using [3-3H]glucose (study 1) and 2-deoxy-[1-3H]glucose (study 2) to assess glucose rate of disappearance (Rd), glycolytic flux (GF), glycogen synthesis, and glucose utilization index by different tissues. Moreover, in study 3, the effect of lactate on the pattern of plasma insulin response to hyperglycemia was evaluated. In study 1, lactate infusion resulted in an increased Rd (38.7 +/- 1.7 vs. 32.3 +/- 1.3 mg.min-1.kg-1; P < 0.01), which was explained by an enhanced rate of glycogen synthesis (23.0 +/- 1.7 vs. 14.7 +/- 1.2 mg.min-1.kg-1; P < 0.001), whereas GF was unchanged. In study 2, lactate-infused animals showed an increased 2-deoxy-glucose disposal and a stimulated glycogen synthase activity as well as an increased glycogen accumulation at the end of the study in several skeletal muscles. In study 3, lactate did not induce any change in either early or late insulin response to hyperglycemia. In conclusion, our results show that muscle glycogen deposition may be enhanced by elevated lactate levels under hyperglycemic conditions and support a role for lactate in the regulation of glucose homeostasis.