RNA-seq reveals that anti-obesity irisin and triiodothyronine (T3) hormones differentially affect the purinergic signaling transcriptomics in differentiated human adipocytes.

The anti-obesity thyroid hormone, triiodothyronine (T3), and irisin, an exercise- and/or cold-induced myokine, stimulate thermogenesis and energy consumption while decreasing lipid accumulation. The involvement of ATP signaling in adipocyte cell function and obesity has attracted increasing attention, but the crosstalk between the purinergic signaling cascade and anti-obesity hormones lacks experimental evidence. In this study, we investigated the effects of T3 and irisin in the transcriptomics of membrane-bound purinoceptors, ectonucleotidase enzymes and nucleoside transporters participating in the purinergic signaling in cultured human adipocytes. The RNA-seq analysis revealed that differentiated adipocytes express high amounts of ADORA1, P2RY11, P2RY12, and P2RX6 gene transcripts, along with abundant levels of transcriptional products encoding to purine metabolizing enzymes (ENPP2, ENPP1, NT5E, ADA and ADK) and transporters (SLC29A1, SCL29A2). The transcriptomics of purinergic signaling markers changed in parallel to the upsurge of "browning" adipocyte markers, like UCP1 and P2RX5, after treatment with T3 and irisin. Upregulation of ADORA1, ADORA2A and P2RX4 gene transcription was obtained with irisin, whereas T3 preferentially upregulated NT5E, SLC29A2 and P2RY11 genes. Irisin was more powerful than T3 towards inhibition of the leptin gene transcription, the SCL29A1 gene encoding for the ENT1 transporter, the E-NPP2 (autotaxin) gene, and genes that encode for two ADP-sensitive P2Y receptors, P2RY1 and P2RY12. These findings indicate that anti-obesity irisin and T3 hormones differentially affect the purinergic signaling transcriptomics, which might point towards new directions for the treatment of obesity and related metabolic disorders that are worth to be pursued in future functional studies.

Approach to adult patients with primary hypothyroidism in some special situations: a position statement from the Thyroid Department of the Brazilian Society of Endocrinology and Metabolism (SBEM)

ABSTRACT Primary hypothyroidism is a common disorder in clinical practice. The management of most cases of hypothyroidism is usually straightforward, but the best approach in some special situations may raise questions among physicians. This position statement was prepared by experts from the Brazilian Society of Endocrinology and Metabolism to guide the management of three special situations, namely, hypothyroidism in the elderly, subclinical hypothyroidism in patients with heart disease, and difficult-to-control hypothyroidism. The authors prepared the present statement after conducting a search on the databases MEDLINE/PubMed, LILACS, and SciELO and selecting articles with the best evidence quality addressing the selected situations. The statement presents information about the current approach to patients in these special situations.

MiR-125a-3p and MiR-320b Differentially Expressed in Patients with Chronic Myeloid Leukemia Treated with Allogeneic Hematopoietic Stem Cell Transplantation and Imatinib Mesylate.

Chronic myeloid leukemia (CML), a hematopoietic neoplasm arising from the fusion of BCR (breakpoint cluster region) gene on chromosome 22 to the ABL (Abelson leukemia virus) gene on chromosome 9 (BCR-ABL1 oncogene), originates from a small population of leukemic stem cells with extensive capacity for self-renewal and an inflammatory microenvironment. Currently, CML treatment is based on tyrosine kinase inhibitors (TKIs). However, allogeneic hematopoietic stem cell transplantation (HSCT-allo) is currently the only effective treatment of CML. The difficulty of finding a compatible donor and high rates of morbidity and mortality limit transplantation treatment. Despite the safety and efficacy of TKIs, patients can develop resistance. Thus, microRNAs (miRNAs) play a prominent role as biomarkers and post-transcriptional regulators of gene expression. The aim of this study was to analyze the miRNA profile in CML patients who achieved cytogenetic remission after treatment with both HSCT-allo and TKI. Expression analyses of the 758 miRNAs were performed using reverse transcription quantitative polymerase chain reaction (RT-qPCR). Bioinformatics tools were used for data analysis. We detected miRNA profiles using their possible target genes and target pathways. MiR-125a-3p stood out among the downregulated miRNAs, showing an interaction network with 52 target genes. MiR-320b was the only upregulated miRNA, with an interaction network of 26 genes. The results are expected to aid future studies of miRNAs, residual leukemic cells, and prognosis in CML.

Comparison of microRNA Expression Profile in Chronic Myeloid Leukemia Patients Newly Diagnosed and Treated by Allogeneic Hematopoietic Stem Cell Transplantation.

Chronic myeloid leukemia (CML) results from a translocation between chromosomes 9 and 22, which generates the Philadelphia chromosome. This forms BCR/ABL1, an active tyrosine kinase protein that promotes cell growth and replication. Despite great progress in CML treatment in the form of tyrosine kinase inhibitors, allogeneic-hematopoietic stem cell transplantation (allo-HSCT) is currently used as an important treatment alternative for patients resistant to these inhibitors. Studies have shown that unregulated expression of microRNAs, which act as oncogenes or tumor suppressors, is associated with human cancers. This contributes to tumor formation and development by stimulating proliferation, angiogenesis, and invasion. Research has demonstrated the potential of microRNAs as biomarkers for cancer diagnosis, prognosis, and therapeutic targets. In the present study, we compared the circulating microRNA expression profiles of 14 newly diagnosed patients with chronic phase-CML and 14 Philadelphia chromosome-negative patients after allo-HSCT. For each patient, we tested 758 microRNAs by reverse transcription quantitative polymerase chain reaction (RT-qPCR) analysis. The global expression profile of microRNAs revealed 16 upregulated and 30 downregulated microRNAs. Target genes were analyzed, and key pathways were extracted and compared. Bioinformatics tools were used to analyze data. Among the downregulated miRNA target genes, some genes related to cell proliferation pathways were identified. These results reveal the comprehensive microRNA profile of CML patients and the main pathways related to the target genes of these miRNAs in cytogenetic remission after allo-HSCT. These results provide new resources for exploring stem cell transplantation-based CML treatment strategies.

Infraphysiological 17ß-estradiol (E2) concentration compromises osteoblast differentiation through Src stimulation of cell proliferation and ECM remodeling stimulus.

It has been shown that 17ß-estradiol (E2) helps to prevent bone loss. This study was undertaken to verify whether E2 action in human osteoblasts involves changes in the transcriptional profile of the TNF-α, IFN-γ, NF-κB, TRAIL, TGF-ß, MMP2, MMP9, RECK, TIMP1, TIMP2, CDK2, CDK4, SRC, RUNX2, and SHH genes. Infraphysiological doses of E2 elevated mRNAs in all genes except for INF-γ, TRAIL, and TGF-ß. Importantly, a significant increase in the CDKs -2 and -4 genes was found, which strongly suggests cell cycle progression, with a potential dependency of Src involvement, as well as a suppression of the osteoblast differentiation machinery, with ECM remodeling being involved. These data suggest that E2 plays an important role in bone formation and remodeling, and Src seems to play a pivotal role in driving cell proliferation and ECM remodeling. Taken together, these findings contribute to an understanding of the effects of infraphysiological E2 on modulating bone homeostasis, favoring bone resorption, and leading to osteoporosis.

Pitfalls and challenges of the purinergic signaling cascade in obesity.

Obesity is a worldwide health problem which have reached pandemic proportions, now also including low and middle-income countries. Excessive or abnormal fat deposition in the abdomen especially in the visceral compartment is tightly associated with a high metabolic risk for arterial hypertension, type II diabetes, cardiovascular diseases, musculoskeletal disorders (especially articular degeneration) and some cancers. Contrariwise, accumulation of fat in the subcutaneous compartment has been associated with a neutral metabolic impact, favoring a lower risk of insulin resistance. Obesity results more often from an avoidable imbalance between food consumption and energy expenditure. There are several recommended strategies for dealing with obesity, including pharmacological therapies, but their success remains incomplete and may not compensate the associated adverse effects. Purinergic signaling operated by ATP and its metabolite, adenosine, has attracted increasing attention in obesity. The extracellular levels of purines often reflect the energy status of a given cell population. Adenine nucleotides and nucleosides fine tuning control adipogenesis and mature adipocytes function via the activation of P2 and P1 purinoceptors, respectively. These features make the purinergic signaling cascade a putative target for therapeutic intervention in obesity and related metabolic syndromes. There are, however, gaps in our knowledge regarding the role of purines in adipocyte precursors differentiation and mature adipocytes functions, as well as their impact among distinct adipose tissue deposits (e.g. white vs. brown, visceral vs. subcutaneous), which warrants further investigations before translation to clinical trials can be made.

The importance of estrogen for bone protection in experimental hyperthyroidism in human osteoblasts.

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 (1 nM) and supraphysiological (10 nM) 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 1 nM and 10 nM T3. E2 was able to restore the bone matrix after an initial decrease using 1 nM and 10 nM T3. 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.

Adiponectin and Serine/Threonine Kinase Akt Modulation by Triiodothyronine and/or LY294002 in 3T3-L1 Adipocytes.

Adipose tissue (AT), an endocrine organ that modulates several physiological functions by synthesizing and releasing adipokines such as adiponectin, is a metabolic target of triiodothyronine (T3). T3 and adiponectin play important roles in controlling normal metabolic functions such as stimulation of fatty acid oxidation and increase in thermogenesis. The phosphatidylinositol 3-kinase (PI3K) pathway is important for the differentiation of preadipocytes into adipocytes and can be activated by T3 for the transcription of specific genes, such as adiponectin. We examined the role of PI3K in adiponectin modulation by T3 action in murine adipocytes (3T3-L1). The 3T3-L1 adipocytes were treated with 1000 nM T3 for 1 h in the presence or absence of 50 µM LY294002 (LY), a PI3K inhibitor. Then, we assessed the expression of adiponectin and the phosphorylated serine/threonine kinase Akt (pAkt), a PI3K signaling protein, in the adipocytes. Adiponectin and pAKT levels were higher in the T3-adipocyte cells, whereas in the LY group adiponectin was elevated and pAKT was decreased compared to the control (C). PI3K pathway inhibition for 1 h and posterior treatment with T3, in LY + T3, reduced the adiponectin level and increased pAKT levels compared to those in LY. T3 stimulated adiponectin levels by PI3K pathway activation and T3 can compensate alteration in the PI3K pathway, because with inhibition of the pathway it is able to maintain the basal levels of adiponectin and pAKT.

Circulating microRNAs expression profile in newly diagnosed and imatinib treated chronic phase - chronic myeloid leukemia.

Chronic myeloid leukemia (CML) is a stem cell derived malignant disorder result of translocation t(9;22)(q34;q11) called Philadelphia chromosome (Ph+). microRNAS (miRNAs) are involved in several biological processes, altering the progression of various pathologies, including CML. This study evaluated whether circulating miRNAs display differential expression profiles in peripheral blood of CML-Chronic Phase (CML-CP) patients newly diagnosed in comparison with CML-CP treated with imatinib. We obtained peripheral blood samples from CML-CP Ph+ patients divided among group 1 (untreated newly diagnosed) and group 2 (treated with imatinib). A pool of total leukocytes from healthy donors was considered as control group. Expression analyses were performed for 768 miRNAs by RT-qPCR array. Bioinformatic tools were used to identify significant pathways and interaction networks. We found 80 deregulated miRNAs between the groups and, according to bioinformatic analysis, they are involved in different pathways, including molecular mechanisms of cancer. The study allows better understanding of disease molecular behavior, and it is useful for possible monitoring CML treatment and prognostic biomarkers identification.

Graves' ophthalmopathy: low-dose dexamethasone reduces retinoic acid receptor-alpha gene expression in orbital fibroblasts

ABSTRACT Objective: Graves' ophthalmopathy (GO) is an autoimmune disease that leads to ocular proptosis caused by fat accumulation and inflammation, and the main treatment is corticosteroid therapy. Retinoid acid receptor-alpha (RARα) seems to be associated with inflammation and adipocyte differentiation. This study aimed to assess the effect of glucocorticoid treatment on orbital fibroblasts of GO patient treated or not with different glucocorticoid doses. Materials and methods: Orbital fibroblasts collected during orbital decompression of a female patient with moderately severe/severe GO were cultivated and treated with 10 nM and 100 nM dexamethasone (Dex). rRARα gene expression in the treated and untreated cells was then compared. Results: Fibroblast RARα expression was not affected by 100 nM Dex. On the other hand, RARα expression was 24% lower in cells treated with 10 nM Dex (p < 0.05). Conclusions: Orbital fibroblasts from a GO patient expressed the RARα gene, which was unaffected by higher, but decreased with lower doses of glucocorticoid.

Investigación electrónica del tratamiento de la hiperprolactinemia en Brasil: endocrinólogos contra ginecólogos / Electronic survey of management of hyperprolactinemia in Brazil: Endocrinologists versus gynecologists

Hyperprolactinemia is a frequent condition in clinical practice, responsible for 20-25% of secondary amenorrhea cases. We performed an electronic survey among members of the Brazilian Society of Metabolism and Endocrinology (SBEM) and the Brazilian Federation of Association of Gynecology and Obstetrics (FEBRASGO) to assess diagnostic and therapeutic preferences for management of hyperprolactinemia. Electronic addresses of SBEM and FEBRASGO members were obtained from the directories of these societies, and these members were invited, through electronic messages (e-mail), to answer an online questionnaire that included 10 questions about the treatment of micro and macropro-lactinomas, maximum dose of dopamine agonist, how to exclude primary hypothyroidism and macroprolactinemia, hyperprolactinemia and pregnancy. We received responses to the questionnaire by e-mail from 521 SBEM members and 233 FEBRASGO members. The results of this survey demonstrate that there are many area of agreement between SBEM and FEBRASGO members and most of their responses follow the latest Endocrine Society Guideline. Relative to a survey performed several years ago, our findings show that SBEM members have incorporated some of latest recommendations in this field. The principal issues of concern for both groups are duration of dopamine agonist treatment for patients with microprolactinoma and dopamine agonist withdrawal during pregnancy.

La hiperprolactinemia es una alteración frecuente, siendo responsable del 20 al 25% de los casos de amenorrea secundaria. Se realizó una investigación electrónica entre los miembros de la Sociedad Brasileña de Endocrinología y Metabología (SBEM) y de la Federación Brasileña de Ginecología y Obstetricia (FEBRASGO) para evaluar sus preferencias en el diagnóstico y el tratamiento de la hiperprolactinemia. Las direcciones electrónicas de miembros SBEM y de FEBRASGO se obtuvieron a partir de los directorios de esas sociedades. Se invitó a estos miembros a responder un cuestionario que incluía 10 cuestiones sobre el tratamiento de los micro y macroprolactinomas, dosis máxima del agonista dopaminérgico, hiperprolactinemia e hipotiroidismo primario, macroprolactinemia, prolactinoma y embarazo. Hemos recibido respuestas de 521 miembros de la SBEM y de 233 miembros FEBRASGO. Los resultados demuestran que hay bastantes áreas de concordancia entre los miembros de la SBEM y de la FEBRASGO y que la mayoría de las respuestas están de acuerdo con el último consenso de la Endocrine Society. En cuanto a una encuesta similar realizada hace años, nuestros resultados muestran que los socios de SBEM incorporaron algunas de las últimas recomendaciones propuestas en esa área. Los principales aspectos de interés en ambos grupos son la duración del tratamiento con el agonista dopaminérgico y la retirada del mismo durante el embarazo.

Bariatric Roux-En-Y Gastric Bypass Surgery: Adipocyte Proteins Involved in Increased Bone Remodeling in Humans.

PURPOSE: Bariatric surgery has been associated with bone remodeling changes. The action of adipokines on the expression of receptor activator of nuclear factor kappa ß ligand (RANKL) and osteoprotegerin (OPG) and on an increase in sclerostin could be related to these changes. MATERIALS AND METHODS: This study aimed to assess the repercussions of weight loss, fat mass (FM), and fat-free mass (FFM) loss and biochemical and hormonal changes on bone remodeling markers after Roux-en-Y gastric bypass (RYGB). Anthropometric data, parathyroid hormone (PTH), bone-specific alkaline phosphatase (BSAP), collagen type 1 C-telopeptide (CTX), 25-hydroxy vitamin D (25-OH-VitD), leptin, adiponectin, RANKL, OPG, and sclerostin of 30 menstruating women were measured preoperatively (Pre), and 3, 12, and 24 months (m) after RYGB. RESULTS: Leptin (34.4 (14.7; 51.9) vs. 22.5 (1.9; 52.7) ng/mL) and OPG (3.6 (1.1; 11.5) vs. 3.4 (1.5; 6) pmol/L) decreased, and adiponectin (7.4 (1.7; 18.4) vs. 13.8 (3.0; 34.6) µg/mL), CTX (0.2 (0.1; 2.2) vs. 0.6 (0.4; 6.0) ng/mL), RANKL (0.1 (0.0; 0.5) vs. 0.3 (0.0; 2.0) pmol/L), and sclerostin (21.7 (3.2; 75.1) vs. 34.8 (6.4; 80.5) pmol/L) increased after 3 m. BSAP increased after 12 m (10.1 (5.4; 18.9) vs. 13.9 (6.9; 30.2) µg/mL) (p < 0.005). CTX correlated positively with adiponectin at 24 m and inversely with leptin Pre; OPG at 3 m; weight, FM, FFM, and leptin at 24 m. RANKL correlated directly with weight at 3 m. Sclerostin correlated inversely with weight Pre and FM at 3 m. BSAP correlated negatively with 25-OH-VitD at 12 m, and positively with PTH at 24 m. CONCLUSIONS: RYGB induced weight loss, and biochemical, hormonal, and body composition changes are associated with higher bone remodeling.

Triiodothyronine (T3) induces HIF1A and TGFA expression in MCF7 cells by activating PI3K.

High expression levels of hypoxia inducing factor 1 alpha are related to mammary carcinogenesis. In previous studies, we demonstrated that expression of transforming growth factor alpha increases upon treatment with triiodothyronine, but this expression does not occur in cellular models that do not express the estrogen receptor, or when cells are co-treated with the anti-estrogen, tamoxifen. The aim of this study was to determine the effect of the hormone triiodothyronine on the expression of the genes HIF1A and TGFA in the breast cancer cell line MCF7. The cell line was subjected to treatment with triiodothyronine at the supraphysiological dose of 10(-8)M for 10min, 30min, 1h, and 4h in the presence or absence of actinomycin D, the gene expression inhibitor, cycloheximide, the protein synthesis inhibitor, and LY294002, the phosphoinositide 3 kinase inhibitor. HIF1A and TGFA mRNA expression was analyzed by reverse transcription polymerase chain reaction. For data analysis, we used analysis of variance complemented by Tukey test and an adopted minimum of 5% significance. We found that HIF1A and TGFA expression increased in the presence of triiodothyronine at all times studied. HIF1A expression decreased in triiodothyronine-treated cells when gene transcription was also inhibited; however, TGFA expression decreased after 10 and 30min of treatment even when transcription was not inhibited. We found that activation of PI3K was necessary for triiodothyronine to modulate HIF1A and TGFA expression.

Gene expression of estrogen receptor-alpha in orbital fibroblasts in Graves' ophthalmopathy.

Graves' ophthalmopathy (GO) is one of the most severe clinical manifestations of Graves' disease (GD), and its treatment might involve high-dose glucocorticoid therapy. The higher incidence of GO among females, and the reported association between polymorphisms of estrogen receptor (ER) and GD susceptibility have led us to question the role of estrogen and its receptor in GO pathogenesis. We, thus, assessed estrogen receptor-alpha (ERA) gene expression in cultures of orbital fibroblasts from a patient with GO before (controls) and after treatment with 10 nM and 100 nM dexamethasone (DEX). Orbital fibroblasts showed ERA gene expression. In the cells treated with 10 nM and 100 nM DEX, ERA gene expression was, respectively, 85% higher and 74% lower, than in the control group. We concluded that ERA gene expression is found in the orbital fibroblasts of patient with GO, which may be affected by glucocorticoids in a dose-related manner. Arch Endocrinol Metab. 2015;59(3):273-6.

Gene expression of estrogen receptor-alpha in orbital fibroblasts in Graves’ ophthalmopathy

Graves’ ophthalmopathy (GO) is one of the most severe clinical manifestations of Graves’ disease (GD), and its treatment might involve high-dose glucocorticoid therapy. The higher incidence of GO among females, and the reported association between polymorphisms of estrogen receptor (ER) and GD susceptibility have led us to question the role of estrogen and its receptor in GO pathogenesis. We, thus, assessed estrogen receptor-alpha (ERA) gene expression in cultures of orbital fibroblasts from a patient with GO before (controls) and after treatment with 10 nM and 100 nM dexamethasone (DEX). Orbital fibroblasts showed ERA gene expression. In the cells treated with 10 nM and 100 nM DEX, ERA gene expression was, respectively, 85% higher and 74% lower, than in the control group. We concluded that ERA gene expression is found in the orbital fibroblasts of patient with GO, which may be affected by glucocorticoids in a dose-related manner. Arch Endocrinol Metab. 2015;59(3):273-6.

Triiodothyronine modulates the expression of leptin and adiponectin in 3T3-L1 adipocytes / Triiodotironina modula a expressão de leptina e adiponectina em adipócitos 3T3-L1

Objective To study the effect of different doses of triiodothyronine on gene expression of the adipokines leptin and adiponectin, at different times, and to evaluate the difference in expression between the two adipokines in each group. Methods 3T3-L1 adipocytes were incubated with triiodothyronine at physiological dose (10nM) and supraphysiological doses (100nM or 1,000nM), or without triiodothyronine (control, C) for 0.5, 6, or 24 hours. Leptin and adiponectin mRNA was detected using real-time polymerase chain reaction (RT-PCR). One-way analyses of variance, Tukey’s test or Student’s t test, were used to analyze data, and significance level was set at 5%. Results Leptin levels decreased in the 1,000nM-dose group after 0.5 hour. Adiponectin levels dropped in the 10nM-dose group, but increased at the 100nM dose. After 6 hours, both genes were suppressed in all hormone concentrations. After 24 hours, leptin levels increased at 10, 100 and 1,000nM groups as compared to the control group; and adiponectin levels increased only in the 100nM group as compared to the control group. Conclusion These results demonstrated fast actions of triiodothyronine on the leptin and adiponectin expression, starting at 0.5 hour, at a dose of 1,000nM for leptin and 100nM for adiponectin. Triiodothyronine stimulated or inhibited the expression of adipokines in adipocytes at different times and doses which may be useful to assist in the treatment of obesity, assuming that leptin is increased and adiponectin is decreased, in obesity cases. .

Objetivo Examinar o efeito de diferentes doses de triiodotironina sobre a expressão gênica das adipocinas leptina e adiponectina, em diferentes períodos de tempo, além de avaliar a diferença de expressão entre as duas adipocinas em cada grupo. Métodos Adipócitos 3T3-L1 foram incubados com triiodotironina nas doses fisiológica (10nM) e suprafisiológicas (100nM ou 1.000nM), ou na ausência de triiodotironina (controle, C) durante 0,5, 6 ou 24 horas. O mRNA das adipocinas foi analisado em tempo real, utilizando a reação em cadeia de polimerase. Para as análises dos dados, foi utilizada a análise de variância, complementada com o teste de Tukey, ou o teste t de Student com 5% de significância. Resultados Os níveis de leptina diminuíram no grupo com dose de 1.000nM em 0,5 hora. A adiponectina também diminuiu no grupo com dose de 10nM, porém se elevou com a dose de 100nM. Após 6 horas, ambos os genes foram suprimidos em todas concentrações de hormônio. Em 24 horas, os níveis de leptina foram elevados em 10, 100 e 1.000nM, em relação ao grupo controle. No que concerne à adiponectina, observou-se aumento apenas no grupo cuja dose foi de 100nM, em comparação ao controle. Conclusão Foram demonstradas ações rápidas da triiodotironina sobre a expressão da leptina e da adiponectina, iniciando em 0,5 hora na dose de 1.000nM, para a primeira, e na dose de 100nM, para a segunda. A triiodotironina estimulou ou inibiu a expressão de adipocinas em adipócitos em diferentes tempos e doses, o que pode auxiliar no tratamento da obesidade, levando em consideração que, nesta, a leptina está aumentada e adiponectina, diminuída. .

Short-term effects of triiodothyronine on thyroid hormone receptor alpha by PI3K pathway in adipocytes, 3T3-L1.

OBJECTIVE: The present study aimed to examine the effects of thyroid hormone (TH), more precisely triiodothyronine (T3), on the modulation of TH receptor alpha (TRα) mRNA expression and the involvement of the phosphatidyl inositol 3 kinase (PI3K) signaling pathway in adipocytes, 3T3-L1, cell culture. MATERIALS AND METHODS: It was examined the involvement of PI3K pathway in mediating T3 effects by treating 3T3-L1 adipocytes with physiological (P=10nM) or supraphysiological (SI =100 nM) T3 doses during one hour (short time), in the absence or the presence of PI3K inhibitor (LY294002). The absence of any treatment was considered the control group (C). RT-qPCR was used for mRNA expression analyzes. For data analyzes ANOVA complemented with Tukey's test was used at 5% significance level. RESULTS: T3 increased TRα mRNA expression in P (1.91±0.13, p<0.001), SI (2.14±0.44, p<0.001) compared to C group (1±0.08). This increase was completely abrogated by LY294002 in P (0.53±0.03, p<0.001) and SI (0.31±0.03, p<0.001). To examine whether TRα is directly induced by T3, we used the translation inhibitor cycloheximide (CHX). The presence of CHX completely abrogated levels TRα mRNA in P (1.15±0.05, p>0.001) and SI (0.99±0.15, p>0.001), induced by T3. CONCLUSION: These results demonstrate that the activation of the PI3K signaling pathway has a role in T3-mediated indirect TRα gene expression in 3T3-L1 adipocytes.

Short-term effects of triiodothyronine on thyroid hormone receptor alpha by PI3K pathway in adipocytes, 3T3-L1 / Efeitos rápidos da triiodotironina no receptor de hormônio tireoidiano alfa pela via PI3K em adipócitos, 3T3-L1

Objective The present study aimed to examine the effects of thyroid hormone (TH), more precisely triiodothyronine (T3), on the modulation of TH receptor alpha (TRα) mRNA expression and the involvement of the phosphatidyl inositol 3 kinase (PI3K) signaling pathway in adipocytes, 3T3-L1, cell culture. Materials and methods: It was examined the involvement of PI3K pathway in mediating T3 effects by treating 3T3-L1 adipocytes with physiological (P=10nM) or supraphysiological (SI =100 nM) T3 doses during one hour (short time), in the absence or the presence of PI3K inhibitor (LY294002). The absence of any treatment was considered the control group (C). RT-qPCR was used for mRNA expression analyzes. For data analyzes ANOVA complemented with Tukey’s test was used at 5% significance level. Results T3 increased TRα mRNA expression in P (1.91±0.13, p<0.001), SI (2.14±0.44, p<0.001) compared to C group (1±0.08). This increase was completely abrogated by LY294002 in P (0.53±0.03, p<0.001) and SI (0.31±0.03, p<0.001). To examine whether TRα is directly induced by T3, we used the translation inhibitor cycloheximide (CHX). The presence of CHX completely abrogated levels TRα mRNA in P (1.15±0.05, p>0.001) and SI (0.99±0.15, p>0.001), induced by T3. Conclusion These results demonstrate that the activation of the PI3K signaling pathway has a role in T3-mediated indirect TRα gene expression in 3T3-L1 adipocytes. .

Objetivo O objetivo do presente estudo foi analisar os efeitos do hormônio tireoidiano (HT), triiodotironina (T3), na modulação da expressão de mRNA do receptor alfa (TRα) de HT e o envolvimento da via de sinalização da via fosfatidilinositol 3-quinase (PI3K) em adipócitos, 3T3-L1. Materiais e métodos: Foi examinado o envolvimento da via PI3K nos efeitos do T3 nos tratamentos de adipócitos, 3T3-L1, nas doses fisiológica (P=10nM) ou suprafisiológica (SI =100 nM) durante uma hora (tempo curto), na ausência ou na presença do inibidor da PI3K (LY294002). A ausência de qualquer tratamento foi considerada o grupo controle (C). RT-qPCR foi utilizado para analisar a expressão do mRNA. Para as análises dos dados, utilizou-se ANOVA complementada com o teste de Tukey a 5% de significância. Resultados O T3 aumentou a expressão de mRNA de TRα em P (1,91±0,13, p<0,001) e SI (2,14±0,44, p<0,001) em comparação com o grupo C (1±0,08). Esse aumento foi completamente abolido por LY294002 em P (0,53±0,03, p<0,001) e SI (0,31±0,03, p<0,001). Para examinar se a expressão de TRα foi diretamente induzida pelo T3, utilizou-se o inibidor de tradução, ciclohexamida (CHX). A presença de CHX reduziu os níveis de mRNA de TRα em P (1,15±0,05, p>0,001) e SI (0,99±0,15, p>0,001), induzidos pelo T3. Conclusão Esses resultados demonstram que a ativação da via de sinalização de PI3K tem um papel importante na expressão do gene TRα mediada indiretamente pelo T3, em adipócitos 3T3-L1. .