ABSTRACT
BACKGROUND: This study evaluated the effects of concurrent isolated training (T) or training combined with the antioxidant N-acetylcysteine (NAC) on cardiac remodeling and oxidative stress in spontaneously hypertensive rats (SHR). METHODS: Six-month-old male SHR were divided into sedentary (S, n = 12), concurrent training (T, n = 13), sedentary supplemented with NAC (SNAC, n = 13), and concurrent training with NAC supplementation (TNAC, n = 14) groups. T and TNAC rats were trained three times a week on a treadmill and ladder; NAC supplemented groups received 120 mg/kg/day NAC in rat chow for eight weeks. Myocardial antioxidant enzyme activity and lipid hydroperoxide concentration were assessed by spectrophotometry. Gene expression of NADPH oxidase subunits Nox2, Nox4, p22 phox, and p47 phox was evaluated by real time RT-PCR. Statistical analysis was performed using ANOVA and Bonferroni or Kruskal-Wallis and Dunn. RESULTS: Echocardiogram showed concentric remodeling in TNAC, characterized by increased relative wall thickness (S 0.40 ± 0.04; T 0.39 ± 0.03; SNAC 0.40 ± 0.04; TNAC 0.43 ± 0.04 *; * p < 0.05 vs T and SNAC) and diastolic posterior wall thickness (S 1.50 ± 0.12; T 1.52 ± 0.10; SNAC 1.56 ± 0.12; TNAC 1.62 ± 0.14 * mm; * p < 0.05 vs T), with improved contractile function (posterior wall shortening velocity: S 39.4 ± 5.01; T 36.4 ± 2.96; SNAC 39.7 ± 3.44; TNAC 41.6 ± 3.57 * mm/s; * p < 0.05 vs T). Myocardial lipid hydroperoxide concentration was lower in NAC treated groups (S 210 ± 48; T 182 ± 43; SNAC 159 ± 33 *; TNAC 110 ± 23 *# nmol/g tissue; * p < 0.05 vs S, # p < 0.05 vs T and SNAC). Nox 2 and p22 phox expression was higher and p47 phox lower in T than S [S 1.37 (0.66-1.66); T 0.78 (0.61-1.04) *; SNAC 1.07 (1.01-1.38); TNAC 1.06 (1.01-1.15) arbitrary units; * p < 0.05 vs S]. NADPH oxidase subunits did not differ between TNAC, SNAC, and S groups. CONCLUSION: N-acetylcysteine supplementation alone reduces oxidative stress in untreated spontaneously hypertensive rats. The combination of N-acetylcysteine and concurrent exercise further decreases oxidative stress. However, the lower oxidative stress does not translate into improved cardiac remodeling and function in untreated spontaneously hypertensive rats.
Subject(s)
Acetylcysteine , Hypertension , NADPH Oxidases , Oxidative Stress , Rats, Inbred SHR , Ventricular Remodeling , Animals , Male , Oxidative Stress/drug effects , Acetylcysteine/pharmacology , Ventricular Remodeling/drug effects , Hypertension/physiopathology , Hypertension/drug therapy , Hypertension/metabolism , NADPH Oxidases/metabolism , NADPH Oxidases/genetics , Rats , Antioxidants/pharmacology , Physical Conditioning, Animal , Disease Models, Animal , NADPH Oxidase 2/metabolism , NADPH Oxidase 2/genetics , NADPH Oxidase 4/metabolism , NADPH Oxidase 4/genetics , Membrane Glycoproteins/metabolism , Membrane Glycoproteins/genetics , Myocardium/metabolism , Myocardium/pathology , Lipid Peroxides/metabolism , Ventricular Function, Left/drug effects , Dietary Supplements , Hypertrophy, Left Ventricular/physiopathology , Hypertrophy, Left Ventricular/prevention & control , Hypertrophy, Left Ventricular/metabolismABSTRACT
ABSTRACT Objective: To verify the physiological action of triiodothyronine T3 on the expression of transforming growth factor α (TGFA) mRNA in MCF7 cells by inhibition of RNA Polymerase II and the MAPK/ERK pathway Materials and methods: The cell line was treated with T3 at a physiological dose (10−9M) for 10 minutes, 1 and 4 hour (h) in the presence or absence of the inhibitors, α-amanitin (RNA polymerase II inhibitor) and PD98059 (MAPK/ERK pathway inhibitor). TGFA mRNA expression was analyzed by RT-PCR. For data analysis, we used ANOVA, complemented with the Tukey test and Student t-test, with a minimum significance of 5%. Results: T3 increases the expression of TGFA mRNA in MCF7 cells in 4 h of treatment. Inhibition of RNA polymerase II modulates the effect of T3 treatment on the expression of TGFA in MCF7 cells. Activation of the MAPK/ERK pathway is not required for T3 to affect the expression of TGFA mRNA. Conclusion: Treatment with a physiological concentration of T3 after RNA polymerase II inhibition altered the expression of TGFA. Inhibition of the MAPK/ERK pathway after T3 treatment does not interfere with the TGFA gene expression in a breast adenocarcinoma cell line.
Subject(s)
Humans , Female , Triiodothyronine/genetics , Breast Neoplasms/genetics , Adenocarcinoma/genetics , Gene Expression Regulation, Neoplastic/genetics , Transforming Growth Factor alpha/genetics , MAP Kinase Signaling System/genetics , Triiodothyronine/metabolism , Triiodothyronine/pharmacology , Proto-Oncogenes/genetics , Breast Neoplasms/metabolism , RNA, Messenger/genetics , Adenocarcinoma/metabolism , Transforming Growth Factor alpha/drug effects , Transforming Growth Factor alpha/metabolism , Cell Line, Tumor/metabolism , MCF-7 Cells/metabolismABSTRACT
Triiodothyronine (T3) and estrogen (E2) play important roles in the bone remodeling process and signaling of receptor activator of the nuclear factor-kappa ß (RANKL) and osteoprotegerin (OPG) expressed by osteoblasts. However, little is known of the molecular action of these hormones in conditions of hyperthyroidism and associated E2 in human cells. AIMS: This study evaluated the effects of the physiological concentration of E2 (10?nM), alone or in association with physiological (1nM) and supraphysiological (10nM) concentrations of T3, on RANKL and OPG gene expression in human osteoblasts. MAIN METHODS: Alkaline phosphatase and osteocalcin assays were performed to verify the presence of mature osteoblasts. After mimicking the experimental hyperthyroidism in osteoblasts untreated or treated with E2, RANKL and OPG gene expression was analyzed by real-time PCR and protein expression by western Blot and ELISA. Alizarin Red staining analyzed the amount of bone matrix after hormonal treatments. KEY FINDINGS: E2 enhanced the gene expression of OPG when associated with 1nM and 10nMT3. E2 was able to restore the bone matrix after an initial decrease using 1nM and 10nMT3. The protective effect of E2 on the RANKL and OPG signaling pathway was demonstrated. E2 restored the bone matrix induced by experimental hyperthyroidism. SIGNIFICANCE: The data highlight the importance of E2 to maintain OPG expression and osteoblast activity against possible loss of bone mass, especially in conditions where T3 is in excess.
ABSTRACT
Triiodothyronine (T3) and estrogen (E2) play important roles in the bone remodeling process and signaling of receptor activator of the nuclear factor-kappa ß (RANKL) and osteoprotegerin (OPG) expressed by osteoblasts. However, little is known of the molecular action of these hormones in conditions of hyperthyroidism and associated E2 in human cells. AIMS: This study evaluated the effects of the physiological concentration of E2 (10?nM), alone or in association with physiological (1nM) and supraphysiological (10nM) concentrations of T3, on RANKL and OPG gene expression in human osteoblasts. MAIN METHODS: Alkaline phosphatase and osteocalcin assays were performed to verify the presence of mature osteoblasts. After mimicking the experimental hyperthyroidism in osteoblasts untreated or treated with E2, RANKL and OPG gene expression was analyzed by real-time PCR and protein expression by western Blot and ELISA. Alizarin Red staining analyzed the amount of bone matrix after hormonal treatments. KEY FINDINGS: E2 enhanced the gene expression of OPG when associated with 1nM and 10nMT3. E2 was able to restore the bone matrix after an initial decrease using 1nM and 10nMT3. The protective effect of E2 on the RANKL and OPG signaling pathway was demonstrated. E2 restored the bone matrix induced by experimental hyperthyroidism. SIGNIFICANCE: The data highlight the importance of E2 to maintain OPG expression and osteoblast activity against possible loss of bone mass, especially in conditions where T3 is in excess.
ABSTRACT
Human adipose tissue-derived stem cells (hASCs) have been subjected to extensive investigation because of their self-renewal properties and potential to restore damaged tissues. In the literature, there are several protocols for differentiating hASCs into osteoblasts, but there is no report on the control of cell viability during this process. In this study, we used osteoblasts derived from hASCs of patients undergoing abdominoplasty. The cells were observed at the beginning and end of bone matrix formation, and the expression of proteins involved in this process, including alkaline phosphatase and osteocalcin, was assessed. RANKL, Osterix, Runx2, Collagen3A1, Osteopontin and BSP expression levels were analyzed using real-time PCR, in addition to a quantitative assessment of protein levels of the markers CD45, CD105, STRO-1, and Nanog, using immunofluorescence. Rhodamine (Rho123), cytochrome-c, caspase-3, P-27, cyclin D1, and autophagy cell markers were analyzed by flow cytometry to demonstrate potential cellular activity and the absence of apoptotic and tumor cell processes before and after cell differentiation. The formation of bone matrix, along with calcium nodules, was observed after 16 days of osteoinduction. The gene expression levels of RANKL, Osterix, Runx2, Collagen3A1, Osteopontin, BSP and alkaline phosphatase activity were also elevated after 16 days of osteoinduction, whereas the level of osteocalcin was higher after 21 days of osteoinduction. Our data also showed that the cells had a high mitochondrial membrane potential and a low expression of apoptotic and tumor markers, both before and after differentiation. Cells were viable after the different phases of differentiation. This proposed methodology, using markers to evaluate cell viability, is therefore successful in assessing different phases of stem cell isolation and differentiation.
ABSTRACT
Human adipose tissue-derived stem cells (hASCs) have been subjected to extensive investigation because of their self-renewal properties and potential to restore damaged tissues. In the literature, there are several protocols for differentiating hASCs into osteoblasts, but there is no report on the control of cell viability during this process. In this study, we used osteoblasts derived from hASCs of patients undergoing abdominoplasty. The cells were observed at the beginning and end of bone matrix formation, and the expression of proteins involved in this process, including alkaline phosphatase and osteocalcin, was assessed. RANKL, Osterix, Runx2, Collagen3A1, Osteopontin and BSP expression levels were analyzed using real-time PCR, in addition to a quantitative assessment of protein levels of the markers CD45, CD105, STRO-1, and Nanog, using immunofluorescence. Rhodamine (Rho123), cytochrome-c, caspase-3, P-27, cyclin D1, and autophagy cell markers were analyzed by flow cytometry to demonstrate potential cellular activity and the absence of apoptotic and tumor cell processes before and after cell differentiation. The formation of bone matrix, along with calcium nodules, was observed after 16 days of osteoinduction. The gene expression levels of RANKL, Osterix, Runx2, Collagen3A1, Osteopontin, BSP and alkaline phosphatase activity were also elevated after 16 days of osteoinduction, whereas the level of osteocalcin was higher after 21 days of osteoinduction. Our data also showed that the cells had a high mitochondrial membrane potential and a low expression of apoptotic and tumor markers, both before and after differentiation. Cells were viable after the different phases of differentiation. This proposed methodology, using markers to evaluate cell viability, is therefore successful in assessing different phases of stem cell isolation and differentiation.