Sandro José Conde

Lycopene supplementation modulates plasma concentrations and epididymal adipose tissue mRNA of leptin, resistin and IL-6 in diet-induced obese rats

Obesity is characterised by chronic low-grade inflammation, and lycopene has been reported to display anti-inflammatory effects. However, it is not clear whether lycopene supplementation modulates adipokine levels in vivo in obesity. To determine whether lycopene supplementation can regulate adipokine expression in obesity, male Wistar rats were randomly assigned to receive a control diet (C, n 6) ora hyperenergetic diet (DIO, n 12) for 6 weeks. After this period, the DIO animals were randomised into two groups: DIO (n 6) and DIO supplemented with lycopene (DIO + L, n 6). The animals received maize oil (C and DIO) or lycopene (DIO + L, 10 mg/kg body weight(BW) per d) by oral administration for a 6-week period. The animals were then killed by decapitation, and blood samples and epididymal adipose tissue were collected for hormonal determination and gene expression evaluation (IL-6, monocyte chemoattractant protein-1(MCP-1), TNF-α, leptin and resistin). There was no detectable lycopene in the plasma of the C and DIO groups. However, the mean lycopene plasma concentration was 24 nmol in the DIO + L group. Although lycopene supplementation did not affect BW or adiposity, it significantly decreased leptin, resistin and IL-6 gene expression in epididymal adipose tissue and plasma concentrations. Also, it significantly reduced the gene expression of MCP-1 in epididymal adipose tissue. Lycopene affects adipokines by reducing leptin, resistin and plasma IL-6 levels. These data suggest that lycopene may be an effective strategy in reducing inflammation in obesity.

Influence of estradiol and triiodothyronine on breast cancer cell lines proliferation and expression of estrogen and thyroid hormone receptors

OBJECTIVE To better understand the estrogen (E2) agonist action of triiodothyronine (T3) the effects of these hormones on ER negative MDA-MB-231 breast cancer cells were compared with those on S30, a clone of MDA-MB-231 stably transfected with ERalpha cDNA, in terms of proliferation and modulation of hormone receptors. RESULTS Growth experiments showed that MDA-MB-231 was not modulated by any hormone or tamoxifen (TAM). Treatment with E2, 10(-8)M or 10(-9)M had little effect on S30 proliferation. T3 at 10(-8)M significantly inhibited proliferation. This effect was not reverted by TAM. Treatments with 10(-8)M concentration of E2 or T3 reduced ERalpha gene expression in S30, an effect partially blocked by association with TAM, with no effect on TR expression. These results suggest that, in S30, 10(-8)M T3 has a similar action to E2 relative to ERalpha gene modulation. CONCLUSIONS Such results emphasize the need of determining T3 levels, before the introduction of antiestrogenic forms of treatment in breast cancer patients.

Tamoxifen inhibits transforming growth factor-α gene expression in human breast carcinoma samples treated with triiodothyronine

Objectives: To examine the effects of triiodothyronine (T3), 17β-estradiol (E2), and tamoxifen (TAM) on transforming growth factor (TGF)-α gene expression in primary breast cancer cell cultures and interactions between the different treatments. Methods and results: Patients included in the study (no.=12) had been newly diagnosed with breast cancer. Fresh human breast carcinoma tissue was cut into 0.3-mm slices. These slices were placed in six 35-mm dishes on 2-ml organ culture medium. Dishes received the following treatments: dish 1: ethanol; dish 2: T3; dish 3: T3+TAM; dish 4: TAM; dish 5: E2; dish 6: E2+TAM. TGF-α mRNA content was normalized to glyceraldehyde-3-phosphate dehydrogenase mRNA levels. All tissues included in this study were positive for estrogen receptor (ER) and thyroid hormone receptor expression. Treatment with T3 for 48 h significantly increased TGF-α mRNA levels compared to controls (15-fold), and concomitant treatment with TAM reduced expression to 3.4-fold compared to controls. When only TAM was added to the culture medium, TGF-α mRNA expression increased 5.3-fold, significantly higher than with all other treatment modalities. Conclusion: We demonstrate that TGF-α mRNA expression is more efficiently upregulated by T3 than E2. Concomitant treatment with TAM had a mitigating effect on the T3 effect, while E2 induced TGF-α upregulation. Our findings show some similarities between primary culture and breast cancer cell lines, but also some important differences: a) induction of TGF-α, a mitogenic protein, by TAM; b) a differential effect of TAM that may depend on relative expression of ER α and β; and c) supraphysiological doses of T3 may induce mitogenic signals in breast cancer tissue under conditions of low circulating E2.

Triiodothyronine and breast cancer.

The thyroid hormones (THs), triiodothyronine (T3) and thyroxine (T4), are essential for survival; they are involved in the processes of development, growth, and metabolism. In addition to hyperthyroidism or hypothyroidism, THs are involved in other diseases. The role of THs in the development and differentiation of mammary epithelium is well established; however, their specific role in the pathogenesis of breast cancer (BC) is controversial. Steroid hormones affect many human cancers and the abnormal responsiveness of the mammary epithelial cells to estradiol (E2) in particular is known to be an important cause for the development and progression of BC. The proliferative effect of T3 has been demonstrated in various types of cancer. In BC cell lines, T3 may foster the conditions for tumor proliferation and increase the effect of cell proliferation by E2; thus, T3 may play a role in the development and progression of BC. Studies show that T3 has effects similar to E2 in BC cell lines. Despite controversy regarding the relationship between thyroid disturbances and the incidence of BC, studies show that thyroid status may influence the development of tumor, proliferation and metastasis.

Human breast tumor slices as an alternative approach to cell lines to individualize research for each patient

There are several breast cancer experimental models including cell lines, which are commonly used due to ease of handling and storage. However, the continued propagation of cell lines and distribution among laboratories results in genetic drift and distancing from the in-vivo model. Primary organ culture of breast cancer slices may produce biological responses with high standard deviation for different samples, reflecting the heterogeneity of different tumors. Thus, the organ culture model system offers a new perspective to the results obtained in the cell lines and offers an alternative for studies that seek to individualize treatment for each patient, an increasingly prominent concern in current cancer therapy.

Upregulation of mRNA myocardium calcium handling in rats submitted to exercise and food restriction

FUNDAMENTO: Treinamento fisico (TF) aumenta a sensibilidade dos hormonios tireoidianos (HT) e a expressao genica de estruturas moleculares envolvidas no movimento intracelular de calcio do miocardio, enquanto a restricao alimentar (RIA) promove efeitos contrarios ao TF. OBJETIVO: Avaliar os efeitos da associacao TF e RIA sobre os niveis plasmaticos dos HT e a producao de mRNA dos receptores HT e estruturas moleculares do movimento de calcio do miocardio de ratos. METODOS: Utilizaram-se ratos Wistar Kyoto divididos em: controle (C, n = 7), RIA (R50, n = 7), exercicio fisico (EX, n = 7) e exercicio fisico + RIA (EX50, n = 7). A RIA foi de 50% e o TF foi natacao (1 hora/dia, cinco sessoes/semana, 12 semanas consecutivas). Avaliaram-se as concentracoes sericas de triiodotironina (T3), tiroxina (T4) e hormonio tireotrofico (TSH). O mRNA da bomba de calcio do reticulo sarcoplasmatico (SERCA2a), fosfolamban (PLB), trocador Na+/Ca+2 (NCX), canal lento de calcio (canal-L), rianodina (RYR), calsequestrina (CQS) e receptor de HT (TRα1 e TRβ1) do miocardio foram avaliados por reacao em cadeia da polimerase (PCR) em tempo real. RESULTADOS: RIA reduziu o T4, TSH e mRNA do TRα1 e aumentou a expressao da PLB, NCX e canal-L. TF aumentou a expressao do TRβ1, canal-L e NCX. A associacao TF e RIA reduziu T4 e TSH e aumentou o mRNA do TRβ1, SERCA2a, NCX, PLB e correlacao do TRβ1 com a CQS e NCX. CONCLUSAO: Associacao TF e RIA aumentou o mRNA das estruturas moleculares calcio transiente, porem o eixo HT-receptor nao parece participar da transcricao genica dessas estruturas.BACKGROUND Chronic exercise and food restriction (FR) have directionally opposite changes in transcription of molecular structures of calcium handling and thyroid hormone (TH) status. OBJECTIVE Evaluate the association of chronic exercise and FR on serum thyroid hormones and gene transcription of molecular structures of intracellular calcium transients and thyroid receptors in myocardium of rats. METHODS Male Wistar Kyoto rats, divided into two groups: control (C, n = 7), FR (R50, n = 7), chronic exercise (EX, n = 7) and chronic exercise + FR (EX50, n = 7). FR was of 50% and exercise was swimming (1 hour/day, 5 days/week, during 12 weeks). Serum concentrations of T3, T4 and TSH were determined. The mRNA gene expression of the sarcoplasmatic reticulum calcium pump (SERCA2a), phospholamban (PLB), Na+/Ca+2 exchanger (NCX), calcium channel L-type (L-channel), ryanodine (RYR), calsequestrin (CQS) and HT receptor (TRα1 and TRβ1) of the myocardium was performed by PCR real-time. RESULTS FR reduced serum levels of T4 and TSH and TRα1 mRNA and increased the expression of PLB, NCX and L-channel. Exercise increased the TRβ1 receptor, L-channel and NCX. The association of exercise and FR reduced plasma T4 and TSH, TRβ1 mRNA increase, SERCA2a, NCX and PLB, and there was a significant correlation of TRβ1 with CQS and NXC. CONCLUSION Chronic exercise and food restriction increased the mRNA of transient Ca2+ proteins; however, TH-receptor axis cannot participate in the transcription of mRNA of myocardial calcium transient proteins.

Estrogen-Responsive Genes Overlap with Triiodothyronine-Responsive Genes in a Breast Carcinoma Cell Line

It has been well established that estrogen plays an important role in the progression and treatment of breast cancer. However, the role of triiodothyronine (T3) remains controversial. We have previously shown its capacity to stimulate the development of positive estrogen receptor breast carcinoma, induce the expression of genes (PR, TGF-alpha) normally stimulated by estradiol (E2), and suppress genes (TGF-beta) normally inhibited by E2. Since T3 regulates growth hormones, metabolism, and differentiation, it is important to verify its action on other genes normally induced by E2. Therefore, we used DNA microarrays to compare gene expression patterns in MCF-7 breast adenocarcinoma cells treated with E2 and T3. Several genes were modulated by both E2 and T3 in MCF-7 cells (Students t-test, P < 0.05). Specifically, we found eight genes that were differentially expressed after treatment with both E2 and T3, including amphiregulin, fibulin 1, claudin 6, pericentriolar material 1, premature ovarian failure 1B, factor for adipocyte differentiation-104, sterile alpha motif domain containing 9, and likely ortholog of rat vacuole membrane protein 1 (fold change > 2.0, pFDR < 0.05). We confirmed our microarray results by real-time PCR. Our findings reveal that certain genes in MCF-7 cells can be regulated by both E2 and T3.

Experimental Hyperthyroidism Decreases Gene Expression and Serum Levels of Adipokines in Obesity

Aims. To analyze the influence of hyperthyroidism on the gene expression and serum concentration of leptin, resistin, and adiponectin in obese animals. Main Methods. Male Wistar rats were randomly divided into two groups: control (C)—fed with commercial chow ad libitum—and obese (OB)—fed with a hypercaloric diet. After group characterization, the OB rats continued receiving a hypercaloric diet and were randomized into two groups: obese animals (OB) and obese with 25 μg triiodothyronine (T3)/100 BW (OT). The T3 dose was administered every day for the last 2 weeks of the study. After 30 weeks the animals were euthanized. Samples of blood and adipose tissue were collected for biochemical and hormonal analyses as well as gene expression of leptin, resistin, and adiponectin. Results. T3 treatment was effective, increasing fT3 levels and decreasing fT4 and TSH serum concentration. Administration of T3 promotes weight loss, decreases all fat deposits, and diminishes serum levels of leptin, resistin, and adiponectin by reducing their gene expression. Conclusions. Our results suggest that T3 modulate serum and gene expression levels of leptin, resistin, and adiponectin in experimental model of obesity, providing new insights regarding the relationship between T3 and adipokines in obesity.

Oncogenic osteomalacia: loss of hypophosphatemia might be the key to avoid misdiagnosis

Diagnosing oncogenic osteomalacia is still a challenge. The disorder is characterized by osteomalacia caused by renal phosphate wasting and low serum concentration of 1,25-dihydroxyvitamin D3 occurring in the presence of a tumor that produces high levels of fibroblast growth factor 23. However, it is possible that the disease is much more misdiagnosed than rare. We present the case of a 42-year-old man with a long-term history of undiagnosed progressive muscle weakness. His laboratory results mainly showed low serum phosphate. Surgical removal of a nasal hemangiopericytoma that had been diagnosed five years earlier, brought him to a symptom-free condition. Even though knowing the underlying etiology would explain his osteomalacia, the patient sought medical help from countless physicians for five consecutive years, and only after adequate treatment a rewarding outcome was achieved.

Exercício e restrição alimentar aumentam o RNAm de proteínas do trânsito de Ca2+ miocárdico em ratos

FUNDAMENTO: Treinamento fisico (TF) aumenta a sensibilidade dos hormonios tireoidianos (HT) e a expressao genica de estruturas moleculares envolvidas no movimento intracelular de calcio do miocardio, enquanto a restricao alimentar (RIA) promove efeitos contrarios ao TF. OBJETIVO: Avaliar os efeitos da associacao TF e RIA sobre os niveis plasmaticos dos HT e a producao de mRNA dos receptores HT e estruturas moleculares do movimento de calcio do miocardio de ratos. METODOS: Utilizaram-se ratos Wistar Kyoto divididos em: controle (C, n = 7), RIA (R50, n = 7), exercicio fisico (EX, n = 7) e exercicio fisico + RIA (EX50, n = 7). A RIA foi de 50% e o TF foi natacao (1 hora/dia, cinco sessoes/semana, 12 semanas consecutivas). Avaliaram-se as concentracoes sericas de triiodotironina (T3), tiroxina (T4) e hormonio tireotrofico (TSH). O mRNA da bomba de calcio do reticulo sarcoplasmatico (SERCA2a), fosfolamban (PLB), trocador Na+/Ca+2 (NCX), canal lento de calcio (canal-L), rianodina (RYR), calsequestrina (CQS) e receptor de HT (TRα1 e TRβ1) do miocardio foram avaliados por reacao em cadeia da polimerase (PCR) em tempo real. RESULTADOS: RIA reduziu o T4, TSH e mRNA do TRα1 e aumentou a expressao da PLB, NCX e canal-L. TF aumentou a expressao do TRβ1, canal-L e NCX. A associacao TF e RIA reduziu T4 e TSH e aumentou o mRNA do TRβ1, SERCA2a, NCX, PLB e correlacao do TRβ1 com a CQS e NCX. CONCLUSAO: Associacao TF e RIA aumentou o mRNA das estruturas moleculares calcio transiente, porem o eixo HT-receptor nao parece participar da transcricao genica dessas estruturas.BACKGROUND Chronic exercise and food restriction (FR) have directionally opposite changes in transcription of molecular structures of calcium handling and thyroid hormone (TH) status. OBJECTIVE Evaluate the association of chronic exercise and FR on serum thyroid hormones and gene transcription of molecular structures of intracellular calcium transients and thyroid receptors in myocardium of rats. METHODS Male Wistar Kyoto rats, divided into two groups: control (C, n = 7), FR (R50, n = 7), chronic exercise (EX, n = 7) and chronic exercise + FR (EX50, n = 7). FR was of 50% and exercise was swimming (1 hour/day, 5 days/week, during 12 weeks). Serum concentrations of T3, T4 and TSH were determined. The mRNA gene expression of the sarcoplasmatic reticulum calcium pump (SERCA2a), phospholamban (PLB), Na+/Ca+2 exchanger (NCX), calcium channel L-type (L-channel), ryanodine (RYR), calsequestrin (CQS) and HT receptor (TRα1 and TRβ1) of the myocardium was performed by PCR real-time. RESULTS FR reduced serum levels of T4 and TSH and TRα1 mRNA and increased the expression of PLB, NCX and L-channel. Exercise increased the TRβ1 receptor, L-channel and NCX. The association of exercise and FR reduced plasma T4 and TSH, TRβ1 mRNA increase, SERCA2a, NCX and PLB, and there was a significant correlation of TRβ1 with CQS and NXC. CONCLUSION Chronic exercise and food restriction increased the mRNA of transient Ca2+ proteins; however, TH-receptor axis cannot participate in the transcription of mRNA of myocardial calcium transient proteins.