RESUMEN
Three types of adipocytes, white, brown, and beige, regulate the systemic energy balance through the storage and expenditure of chemical energy. In addition, adipocytes produce various bioactive molecules known as adipokines. In contrast to white adipocyte-derived molecules, less information is available on the adipokines produced by brown adipocytes (batokine). This study explored the regulatory expression of interleukin (IL)-6 in cell culture studies. Norepinephrine or a nonselective ß-adrenergic receptor agonist increased the expression of IL-6 in primary brown adipocytes and HB2 brown adipocytes. Treatment with forskolin (Fsk), an activator of the cAMP-dependent protein kinase (PKA) pathway (downstream signaling of the ß-adrenergic receptor), efficiently stimulated IL-6 expression in brown adipocytes and myotubes. Phosphorylated CREB and phosphorylated p38 MAP kinase levels were increased in Fsk-treated brown adipocytes within 5 min. In contrast, a long-term (â¼60 min and â¼4 h) treatment with Fsk was required for increase in STAT3 phosphorylation and C/EBPß expression, respectively. The PKA, p38 MAP kinase, STAT3, and C/EBPß pathways are required for the maximal IL-6 expression induced by Fsk, which were verified by use of various inhibitors of these signal pathways. Vitamin C enhanced Fsk-induced IL-6 expression through the extracellular signal-regulated kinase activity. The present study provides basic information on the regulatory expression of IL-6 in activated brown adipocytes.
Asunto(s)
Adipocitos Marrones , Proteína Quinasa 14 Activada por Mitógenos , Animales , Ratones , Adipocitos Blancos , Adipoquinas , Colforsina/farmacología , Interleucina-6RESUMEN
Carnosine, which is abundant in meat, is a dipeptide composed of ß-alanine and histidine, known to afford various health benefits. It has been suggested that carnosine can elicit an anti-obesity effect via induction and activation of brown/beige adipocytes responsible for non-shivering thermogenesis. However, the relationship between carnosine and brown/beige adipocytes has not been comprehensively elucidated. We hypothesized that ß-alanine directly modulates brown/beige adipogenesis and performed an in vitro assessment to test this hypothesis. HB2 brown preadipocytes were differentiated using insulin from day 0. Cells were treated with various concentrations of ß-alanine (12.5-100 µM) during adipogenesis (days 0-8) and differentiation (days 8-10). Then, cells were further stimulated with or without forskolin, an activator of the cAMP-dependent protein kinase pathway, on day 8 or day 10 for 4 h before harvesting. We observed that HB2 cells expressed molecules related to the transport and signal transduction of ß-alanine. Treatment with ß-alanine during brown adipogenesis dose-dependently enhanced forskolin-induced Ucp1 expression; this was not observed in differentiated brown adipocytes. Consistent with these findings, treatment with ß-alanine during days 0-8 increased phosphorylation levels of CREB in forskolin-treated HB2 cells. In addition, ß-alanine treatment during brown adipogenesis increased the expression of Pparα, known to induce brown/beige adipogenesis, in a dose-dependent manner. These findings revealed that ß-alanine could target HB2 adipogenic cells and enhance forskolin-induced Ucp1 expression during brown adipogenesis, possibly by accelerating phosphorylation and activation of CREB. Thus, ß-alanine, a carnosine-constituting amino acid, might directly act on brown adipogenic cells to stimulate energy expenditure.
Asunto(s)
Adipocitos Marrones , Carnosina , Adipocitos Marrones/metabolismo , Adipogénesis , Carnosina/metabolismo , Carnosina/farmacología , Colforsina/metabolismo , Colforsina/farmacología , Termogénesis , Proteína Desacopladora 1/metabolismo , beta-Alanina/metabolismo , beta-Alanina/farmacologíaRESUMEN
The vagina is the site of copulation and serves as the birth canal. It also provides protection against external pathogens. In mice, due to the absence of cervical glands, the vaginal epithelium is the main producer of vaginal mucus. The development and differentiation of vaginal epithelium-constituting cells and the molecular characteristics of vaginal mucus have not been thoroughly examined. Here, we characterized vaginal mucous cell development and the expression of mucus-related factors in pregnant mice. The vaginal mucous epithelium layer thickened and became multilayered after Day 12 of pregnancy and secreted increasing amounts of mucus until early postpartum. Using histochemistry and transmission electron microscopy, we found supra-basal mucous cells as probable candidates for precursor cells. In vaginal mucous cells, the expression of TFF1, a stabilizer of mucus, was high, and some members of mucins and antimicrobial peptides (MUC5B and DEFB1) were expressed in a stage-dependent manner. In summary, this study presents the partial characterization of vaginal epithelial mucous cell lineage and expression of genes encoding several peptide substances that may affect vaginal tissue homeostasis and mucosal immunity during pregnancy and parturition.
Asunto(s)
Células Epiteliales/metabolismo , Expresión Génica , Ratones/metabolismo , Moco/metabolismo , Preñez/metabolismo , Vagina/metabolismo , Animales , Femenino , Ratones/crecimiento & desarrollo , Embarazo , Preñez/genéticaRESUMEN
Accurate identification of the murine estrous cycle using vaginal exfoliative cytology is the initial and crucial step for controlled reproduction of this species. However, it is generally difficult to discriminate each stage of the cycle, and thus to select pro-estrous mice for mating. To increase the accuracy of identification of the pro-estrous stage, we re-evaluated the vaginal fold histology and modified the method of exfoliative cytology. Tissue fixation using methanol in Carnoy's solution but not paraformaldehyde, combined with Alcian blue staining but not the conventional Giemsa staining, resulted in better manifestation of mucosal cell layers in the vaginal epithelium just above the keratinized layer. This mucous layer in the fold histology was found to form specifically in the pro-estrous and late di-estrous stages, and the mucous cells exfoliated in smear samples only in the pro-estrous stage. This novel method was found, by a blinded test, to increase the rate of accurate identification of the pro-estrous stage compared to the conventional method (80% vs 50%). Consistent with this finding, the mating experiment with "pro-estrous" females selected by the novel method revealed a significantly higher success rate than that with the conventional method (78.0% vs 47.5%). Thus, our study demonstrates vaginal exfoliative mucous cells as a better potential marker to detect the "receptive" state of female mice that leads to an improved success rate of mating.
Asunto(s)
Células Epiteliales/citología , Proestro , Reproducción , Vagina/citología , Animales , Femenino , Masculino , Ratones , Ratones Endogámicos ICRRESUMEN
Brown and beige adipocytes dissipate energy as heat. Thus, the activation of brown adipocytes and the emergence of beige adipocytes in white adipose tissue (WAT) are suggested to be useful for preventing and treating obesity. Although ß3 -adrenergic receptor activation is known to stimulate lipolysis and activation of brown and beige adipocytes, fat depot-dependent changes in metabolite concentrations are not fully elucidated. The current study examined the effect of treatment with CL-316,243, a ß3 -adrenergic receptor agonist, on the relative abundance of metabolites in interscapular brown adipose tissue (iBAT), inguinal WAT (ingWAT), and epididymal WAT (epiWAT). Intraperitoneal injection of CL-316,243 (1 mg/kg) for 3 consecutive days increased the relative abundance of several glycolysis-related metabolites in all examined fat depots. The cellular concentrations of metabolites involved in the citric acid cycle and of free amino acids were also increased in epiWAT by CL-316,243. CL-316,243 increased the expression levels of several enzymes and transporters related to glucose metabolism and amino acid catabolism in ingWAT and iBAT but not in epiWAT. CL-316,243 also induced the emergence of more beige adipocytes in ingWAT than in epiWAT. Furthermore, adipocytes surrounded by macrophages were detected in the epiWAT of mice given CL-316,243. The current study reveals the fat depot-dependent modulation of cellular metabolites in CL-316,243-treated mice, presumably resulting from differential regulation of cell metabolism in different cell populations.
Asunto(s)
Tejido Adiposo Pardo/metabolismo , Tejido Adiposo Blanco/metabolismo , Agonistas de Receptores Adrenérgicos beta 3/farmacología , Dioxoles/farmacología , Receptores Adrenérgicos beta 3/metabolismo , Transducción de Señal/efectos de los fármacos , Adipocitos Beige/metabolismo , Agonistas de Receptores Adrenérgicos beta 3/administración & dosificación , Aminoácidos/metabolismo , Animales , Dioxoles/administración & dosificación , Glucosa/metabolismo , Inyecciones Intraperitoneales , Metabolismo de los Lípidos/efectos de los fármacos , Macrófagos/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , TranscriptomaRESUMEN
Beige adipocytes and brown adipocytes can generate heat by using mitochondrial uncoupling protein 1 (Ucp1), a thermogenic protein. Browning/beiging is the emergence of beige adipocytes in white adipose tissues (WAT) for cold acclimatization. Here we show the existence of brown/beige adipocytes in retro-orbital WAT in mice. Histologically, Ucp1-positive cells with multilocular lipid droplets were abundant in retro-orbital WAT of immature mice; those cells decreased in number with age. However, Ucp1-positive adipocytes with multilocular lipid droplets emerged in retro-orbital WAT in adult mice, due to cold exposure as short as 3â¯h. Consistent with this observation, the expression level of Ucp1 mRNA was enhanced in tissues upon cold exposure. Furthermore, eye surface temperature remained within a physiological range during cold challenge. RT-qPCR suggested a mixed phenotype of brown and beige adipocytes in retro-orbital WAT. Transmission electron microscopic observation showed multiple lipid droplets and numerous mitochondria with high cristae density in retro-orbital WAT cells from both control and cold-exposed mice. Our results suggest that warming of the orbital cavity by browning/beiging in retro-orbital WAT is a protective mechanism against cold cataract caused by lowered lens temperature.
Asunto(s)
Adipocitos Beige/fisiología , Tejido Adiposo/fisiología , Envejecimiento/fisiología , Catarata/fisiopatología , Frío , Adipocitos Beige/metabolismo , Animales , Ratones , Proteína Desacopladora 1/metabolismoRESUMEN
Activin E, a member of the TGF-ß super family, is a protein dimer of mature inhibin ßE subunits. Recently, it is reported that hepatic activin E may act as a hepatokine that alter whole body energy/glucose metabolism in human. However, orthologues of the activin E gene have yet to be identified in lower vertebrates, including fish. Here, we cloned the medaka (Oryzias latipes) activin E cDNA from liver. Among all the mammalian inhibin ß subunits, the mature medaka activin E amino acid sequence shares the highest homology with mammalian activin E. Recombinant expression studies suggest that medaka activin E, the disulfide-bound mature form of mature inhibin ßE subunits, may exert its effects in a way similar to that in mammals. Although activin E mRNA is predominantly expressed in liver in mammals, it is ubiquitously expressed in medaka tissues. Since expression in the liver was enhanced after a high fat diet, medaka activin E may be associated with energy/glucose metabolism, as shown in mice and human.
Asunto(s)
Subunidades beta de Inhibinas/metabolismo , Subunidades beta de Inhibinas/fisiología , Oryzias/genética , Activinas/metabolismo , Activinas/fisiología , Secuencia de Aminoácidos , Animales , ADN Complementario/metabolismo , Inhibinas/genética , Inhibinas/metabolismo , Hígado/metabolismo , Oryzias/metabolismo , ARN Mensajero/metabolismo , Factor de Crecimiento Transformador beta/metabolismoRESUMEN
Dietary vitamin A status affects energy metabolism. The present study explored the effect of all-trans retinoic acid (ATRA) on the expression levels of molecules and metabolites of brown adipocytes. Chronic ATRA treatment was initiated during the early stage (days 0-8) or late stage (days 8-12) of adipogenesis. Treatment with ATRA during the early and late stage of adipogenesis resulted in an increase in the expression level of Ucp1 and Cidea, genes highly expressed in brown adipocytes, on day 8 and day 12, respectively, whereas expression of Pgc-1α, another gene expressed during brown adipogenesis, was unaffected by ATRA. Non-targeted metabolomic analyses indicated that the pathways related to the glucose metabolism were affected by ATRA, irrespective of the differentiation stage. Cellular levels of glucose 6-phosphate, fructose 6-phosphate, citric acid, and succinic acid decreased after ATRA treatment on days 8 and 12. In contrast, glucose level was higher in ATRA-treated cells on day 8, but it was lower on day 12. ATRA decreased the cellular level of aconitic acid, fumaric acid, and malic acid on day 12 but not on day 8. Furthermore, ATRA increased the expression level of Hxk2 and downregulated the expressions of G6pdh and Pfkl/Pfkp on day 8 but not on day 12. Together, the results indicate that the chronic treatment with ATRA stimulated the formation of activated brown adipocytes, eventually leading to alterations in the levels of cellular metabolites related to glucose metabolism. SIGNIFICANCE OF THE STUDY: Significance of the study treatment with all-trans retinoic acid (ATRA) during the early and late stage of adipogenesis increased the expression of Ucp1 and Cidea, genes highly expressed in brown adipocytes, on day 8 and day 12. Cellular levels of glucose 6-phosphate, fructose 6-phosphate, citric acid, and succinic acid decreased after ATRA treatment on days 8 and 12. In contrast, glucose level was higher in ATRA-treated cells on day 8, but it was lower on day 12. The present results indicate that ATRA stimulated the formation of activated brown adipocytes, eventually leading to alterations in the levels of cellular metabolites related to glucose metabolism.
Asunto(s)
Adipocitos Marrones/efectos de los fármacos , Adipocitos Marrones/metabolismo , Diferenciación Celular/efectos de los fármacos , Metabolómica , Células Madre/efectos de los fármacos , Células Madre/metabolismo , Tretinoina/farmacología , Adipocitos Marrones/citología , Células Cultivadas , Perfilación de la Expresión Génica , Humanos , ARN/genética , Células Madre/citología , Tretinoina/administración & dosificaciónRESUMEN
Hepcidin is a liver-derived hormone that negatively regulates serum iron levels and is mainly regulated at the transcriptional level. Previous studies have clarified that in addition to hepatic iron levels, inflammation also efficiently increases hepatic hepcidin expression. The principle regions responsible for efficient hepcidin transcription are bone morphogenetic protein-responsive elements (BMP-REs) 1 and 2 as well as the signal transducer and activator of transcription 3-binding site (STAT-BS). Here, we show that the proinflammatory cytokine interleukin-1ß (IL-1ß) efficiently increases hepcidin expression in human HepG2 liver-derived cells and primary mouse hepatocytes. The primary region responsible for IL-1ß-mediated hepcidin transcription was the putative CCAAT enhancer-binding protein (C/EBP)-binding site (C/EBP-BS) at the hepcidin promoter spanning nucleotides -329 to -320. IL-1ß induces the expression of C/EBPδ but neither C/EBPα nor C/EBPß in hepatocytes, and C/EBPδ bound to the C/EBP-BS in an IL-1ß-dependent manner. Lipopolysaccharide (LPS) induced the expression of IL-1ß in Kupffer cells and hepatocytes in the mouse liver; furthermore, the culture supernatants from the macrophage-like cell line RAW264.7 treated with LPS potentiated the stimulation of hepcidin expression in hepatocytes. The present study reveals that: 1) inflammation induces IL-1ß production in Kupffer cells and hepatocytes; 2) IL-1ß increases C/EBPδ expression in hepatocytes; and 3) induction of C/EBPδ activates hepcidin transcription via the C/EBP-BS that has been uncharacterized yet. In cooperation with the other pathways activated by inflammation, IL-1ß pathway stimulation leads to excess production of hepcidin, which could be causative to anemia of inflammation.
Asunto(s)
Proteína delta de Unión al Potenciador CCAAT/agonistas , Hepatocitos/metabolismo , Hepcidinas/agonistas , Interleucina-1beta/metabolismo , Regiones Promotoras Genéticas , Regulación hacia Arriba , Animales , Proteína delta de Unión al Potenciador CCAAT/antagonistas & inhibidores , Proteína delta de Unión al Potenciador CCAAT/genética , Proteína delta de Unión al Potenciador CCAAT/metabolismo , Células Cultivadas , Medios de Cultivo Condicionados , Células Hep G2 , Hepatocitos/citología , Hepatocitos/efectos de los fármacos , Hepatocitos/inmunología , Hepcidinas/genética , Hepcidinas/metabolismo , Humanos , Interleucina-1beta/genética , Macrófagos del Hígado/citología , Macrófagos del Hígado/efectos de los fármacos , Macrófagos del Hígado/inmunología , Macrófagos del Hígado/metabolismo , Lipopolisacáridos/toxicidad , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Macrófagos/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos ICR , Regiones Promotoras Genéticas/efectos de los fármacos , Células RAW 264.7 , Interferencia de ARN , Ratas Sprague-Dawley , Proteínas Recombinantes/metabolismo , Regulación hacia Arriba/efectos de los fármacosRESUMEN
Activity of brown/beige adipocytes is higher in women than in men. The expression level of uncoupling protein 1 (UCP1) is largely consistent with the thermogenic activity in brown/beige adipocytes. The present study examined the direct effects of sex hormones on Ucp1 expression in brown adipocytes and beige adipocytes, which were differentiated from HB2 brown preadipocytes and 3T3-L1 white preadipocytes, respectively; treatment with estradiol or testosterone was used during the early (days 0-8) or late stage (days 8-12) of brown adipogenesis and beige adipogenesis. On day 8 or day 12, cells were treated with or without isoproterenol (Iso), an agonist for the ß-adrenergic receptor, for 4 hours. Furthermore, the sex of cells was examined; the sex-determining region y gene, which is located on the y chromosome, was present in HB2 cells, but not in 3T3-L1 cells, suggesting that HB2 cells and 3T3-L1 cells are male and female cells, respectively. Treatment with 17ß-estradiol during the early stage of brown adipogenesis enhanced the responsiveness to Iso on Ucp1 induction, whereas treatment during the late stage of brown adipogenesis decreased Ucp1 expression in unstimulated brown adipocytes. Estradiol decreased Iso-induced Ucp1 expression during the early stage of beige adipogenesis. Treatment with testosterone during the early stage of brown adipogenesis did not affect Ucp1 expression but increased the responsiveness to Iso on Ucp1 induction by the treatment during the late stage of brown adipogenesis. The present results suggest that sex hormones modulate the expression level of Ucp1 in brown/beige adipocytes in a stage-dependent manner. Direct effects of sex hormones in brown/beige adipogenesis were evaluated. Treatment with 17ß-estradiol during the early stage of brown adipogenesis enhanced the responsiveness to isoproterenol (Iso), an agonist for the ß-adrenergic receptor, on Ucp1 induction, whereas treatment during the late stage of brown adipogenesis decreased Ucp1 expression in unstimulated brown adipocytes. Estradiol decreased Iso-induced Ucp1 expression during the early stage of beige adipogenesis. Testosterone during the late stage of brown adipogenesis increased the responsiveness to Iso on Ucp1 induction. Sex hormones modulate the expression level of Ucp1 in brown/beige adipocytes in a stage-dependent manner.
Asunto(s)
Estradiol/farmacología , Expresión Génica/efectos de los fármacos , Testosterona/farmacología , Proteína Desacopladora 1/metabolismo , Células 3T3-L1 , Adipocitos Beige/citología , Adipocitos Beige/metabolismo , Adipocitos Marrones/citología , Adipocitos Marrones/metabolismo , Animales , Diferenciación Celular , Línea Celular , Femenino , Isoproterenol/farmacología , Masculino , Ratones , Ratones Endogámicos C57BLRESUMEN
We demonstrated that castration enhanced the expression of uncoupling protein 1 (Ucp1), a thermogenic protein, in brown adipose tissue (BAT) and subcutaneous (sc) white adipose tissue (WAT) in male mice. Castration of male mice increased body temperature and reduced body weight gain compared with those of sham-operated mice. BAT Ucp1 mRNA expression in castrated male mice was significantly higher than that in sham-operated mice. Histologically, cells with multilocular fat droplets were observed in the castrated inguinal scWAT. Immunohistochemical staining revealed that these cells positively reacted with the anti-Ucp1 antibody. The Ucp1-positive area near the inguinal lymph node in the castrated WAT was extensive compared with that of the sham-operated WAT. Castration-induced Ucp1 up-regulation in scWAT was suppressed by high-fat diet feeding. These findings suggest that thermogenesis by BAT activation and scWAT browning contribute to castration-induced inhibition of body weight gain. However, considering that the effect of castration was blunted by high-fat diet consumption, thermogenesis stimulation in response to castration is inhibited by chronic over-nutrition.
Asunto(s)
Tejido Adiposo Pardo/metabolismo , Tejido Adiposo Blanco/metabolismo , Orquiectomía , Grasa Subcutánea/metabolismo , Adipocitos/metabolismo , Animales , Temperatura Corporal , Peso Corporal , Dieta Alta en Grasa , Expresión Génica , Inmunohistoquímica , Masculino , Ratones Endogámicos C57BL , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Termogénesis , Proteína Desacopladora 1/genética , Proteína Desacopladora 1/metabolismoRESUMEN
The ingestion of capsaicin, the principle pungent component of red and chili peppers, induces thermogenesis, in part, through the activation of brown adipocytes expressing genes related to mitochondrial biogenesis and uncoupling such as peroxisome proliferator-activated receptor (Ppar) γ coactivator-1α (Pgc-1α) and uncoupling protein 1 (Ucp1). Capsaicin has been suggested to induce the activation of brown adipocytes, which is mediated by the stimulation of sympathetic nerves. However, capsaicin may directly affect the differentiation of brown preadipocytes, brown adipocyte function, or both, through its significant absorption. We herein demonstrated that Trpv1, a capsaicin receptor, is expressed in brown adipose tissue, and that its expression level is increased during the differentiation of HB2 brown preadipocytes. Furthermore, capsaicin induced calcium influx in brown preadipocytes. A treatment with capsaicin in the early stage of brown adipogenesis did not affect lipid accumulation or the expression levels of Fabp4 (a gene expressed in mature adipocytes), Pparγ2 (a master regulator of adipogenesis) or brown adipocyte-selective genes. In contrast, a treatment with capsaicin in the late stage of brown adipogenesis slightly increased the expression levels of Fabp4, Pparγ2 and Pgc-1α. Although capsaicin did not affect the basal expression level of Ucp1, Ucp1 induction by forskolin was partially inhibited by capsaicin, irrespective of the dose of capsaicin. The results of the present study suggest the direct effects of capsaicin on brown adipocytes or in the late stage of brown adipogenesis.
Asunto(s)
Adipocitos Marrones/citología , Adipogénesis/efectos de los fármacos , Capsaicina/farmacología , Adipocitos Marrones/efectos de los fármacos , Adipocitos Marrones/metabolismo , Tejido Adiposo Pardo/citología , Tejido Adiposo Pardo/efectos de los fármacos , Tejido Adiposo Pardo/metabolismo , Animales , Células Cultivadas , Proteínas de Unión a Ácidos Grasos/genética , Proteínas de Unión a Ácidos Grasos/metabolismo , Femenino , Expresión Génica/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , Canales Catiónicos TRPV/genética , Canales Catiónicos TRPV/metabolismoRESUMEN
Brown adipocytes dissipate chemical energy in the form of heat through the expression of mitochondrial uncoupling protein 1 (Ucp1); Ucp1 expression is further upregulated by the stimulation of ß-adrenergic receptors in brown adipocytes. An increase in energy expenditure by activated brown adipocytes potentially contributes to the prevention of or therapeutics for obesity. The present study examined the effects of milk by-products, buttermilk and butter oil, on brown adipogenesis and the function of brown adipocytes. The treatment with buttermilk modulated brown adipogenesis, depending on the product tested; during brown adipogenesis, buttermilk 1 inhibited the differentiation of HB2 brown preadipocytes. In contrast, buttermilk 3 and 5 increased the expression of Ucp1 in the absence of isoproterenol (Iso), a ß-adrenergic receptor agonist, suggesting the stimulation of brown adipogenesis. In addition, the Iso-induced expression of Ucp1 was enhanced by buttermilk 2 and 3. The treatment with buttermilk did not affect the basal or induced expression of Ucp1 by Iso in HB2 brown adipocytes, except for buttermilk 5, which increased the basal expression of Ucp1. Conversely, butter oil did not significantly affect the expression of Ucp1, irrespective of the cell phase of HB2 cells, ie, treatment during brown adipogenesis or of brown adipocytes. The results of the present study indicate that buttermilk is a regulator of brown adipogenesis and suggest its usefulness as a potential food material for antiobesity.
Asunto(s)
Adipocitos Marrones/metabolismo , Adipogénesis , Suero de Mantequilla , Leche/química , Adipocitos Marrones/citología , Adipogénesis/genética , Animales , Diferenciación Celular , Regulación de la Expresión Génica , Ghee , Humanos , Coloración y EtiquetadoRESUMEN
BACKGROUND: Brown adipocytes generate heat through the expression of mitochondrial Ucp1. Compared with the information on the regulatory differentiation of white preadipocytes, the factors affecting brown adipogenesis are not as well understood. The present study examined the roles of the Tgf-ß family members Bmp, Tgf-ß and Activin during differentiation of HB2 brown preadipocytes. METHODS: Endogenous Bmp activity and effects of exogenous Tgf-ß family members were examined. Role of Srebp1c in brown adipogenesis was further explored. RESULTS: Although Bmp7 has been suggested to be a potent stimulator of brown adipogenesis, it affected neither the expression of brown adipocyte-selective genes nor Ucp1 induction in response to a ß adrenergic receptor agonist. Unlike in 3T3-L1 white preadipocytes, endogenous Bmp activity was not required for brown adipogenesis; treatment with inhibitors of the Bmp pathway did not affect differentiation of preadipocytes. Administration of Tgf-ß1 or Activin A efficiently decreased the insulin-induced expression of brown adipocyte-selective genes. Tgf-ß1 and Activin A decreased the expression of Pparγ2 and C/ebpα, suggesting the inhibition of adipogenesis. The Tgf-ß- and Activin-induced inhibition of brown adipogenesis was mediated by the repression of Srebp1c expression; Tgf-ß1 and Activin A blocked Srebp1c gene induction in response to the differentiation induction, and knock-down of Srebp1 expression inhibited brown adipogenesis. CONCLUSION: Endogenous Bmp is dispensable for brown adipogenesis, and Srebp1c is indispensable, which is negatively regulated by Tgf-ß and Activin. GENERAL SIGNIFICANCE: Control of activity of the Tgf-ß family is potentially useful for maintenance of energy homeostasis through manipulation of brown adipogenesis.
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Activinas/fisiología , Adipocitos/citología , Adipocitos/metabolismo , Adipogénesis/fisiología , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/fisiología , Factor de Crecimiento Transformador beta1/fisiología , Células 3T3-L1 , Activinas/genética , Activinas/metabolismo , Animales , Proteína Morfogenética Ósea 7/genética , Proteína Morfogenética Ósea 7/metabolismo , Proteínas Potenciadoras de Unión a CCAAT/genética , Proteínas Potenciadoras de Unión a CCAAT/metabolismo , Diferenciación Celular/fisiología , Regulación hacia Abajo , Insulina/metabolismo , Ratones , PPAR gamma/genética , PPAR gamma/metabolismo , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/genética , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/metabolismo , Factor de Crecimiento Transformador beta1/genética , Factor de Crecimiento Transformador beta1/metabolismoRESUMEN
It is agreed that many of the antitumor effects of (-)-epigallocatechin gallate (EGCG) are mediated by various other effects. We report a new finding, namely, the antiproliferation potential and mechanism of methylated-(3'')-epigallocatechin gallate analog (MethylEGCG) having a stronger anti-oxidation effect than EGCG. MethylEGCG inhibited activity of vascular endothelial growth factor (VEGF)-depended VEGF receptor 2 and p42/44 MAPK, cell proliferation, and tube formation in human umbilical vascular endothelial cells (HUVECs) at 1 µ M. Even low- dose (1.1 mg/kg i.p. 8.3 mg/kg p.o.) administration suppressed tumor growth in xenografted Huh7 hepatoma mice by 50%. CD31 positive cells, visualized in blood vessels, were reduced in tumors by 18%, suggesting high antitumor activity via inhibition of angiogenesis. This study indicated that the modification of the 3'' position methylation of EGCG (MethylEGCG) could reduce cell growth effects at a low concentration in vivo.
Asunto(s)
Carcinoma Hepatocelular/patología , Catequina/análogos & derivados , Neovascularización Patológica/tratamiento farmacológico , Animales , Antioxidantes/farmacología , Carcinoma Hepatocelular/metabolismo , Catequina/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Humanos , Neoplasias Hepáticas/metabolismo , Ratones , Proteína Quinasa 1 Activada por Mitógenos/genética , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Neovascularización Patológica/patología , Factor A de Crecimiento Endotelial Vascular/genética , Factor A de Crecimiento Endotelial Vascular/metabolismo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
BACKGROUND AND AIM: Preclinical studies in rodent models of chronic liver fibrosis have shown that transplantation of peripheral blood (PB) CD34(+) cells leads to hepatic regeneration and a reduction of liver fibrosis by suppressing hepatic stellate cell activity and increasing matrix metalloproteinase activity. The aim of this study was to examine the safety and clinical efficacy of intrahepatic transplantation of autologous granulocyte colony-stimulating factor (G-CSF)-mobilized PB-CD34(+) cells in patients with decompensated liver cirrhosis. METHODS: PB-CD34(+) cells were isolated from G-CSF-mobilized apheresis products. Ten patients were treated with G-CSF-mobilized PB-CD34(+) cells (treatment group) and seven patients were treated with standard medical therapy. For mobilization, patients in the treatment group received subcutaneous injections of 10 µg G-CSF/kg/day for 5 days. The cells were then injected at three different doses (5 × 10(5) , 1 × 10(6) and 2 × 10(6) cells/kg) through the hepatic artery. Thereafter, all patients were followed up for 24 months. RESULTS: G-CSF treatment and leukapheresis were well tolerated, and no serious adverse events were observed. Patients in the treatment group had a significant but transient splenomegaly. After 24 weeks, serum albumin was significantly increased in patients who had received middle or high doses of CD34(+) cells compared with baseline. Doppler ultrasound showed a significant increase in hepatic blood flow velocity and blood flow volume after CD34(+) cell therapy. The hepatic vein pressure gradient decreased in two patients who received high-dose CD34(+) cells at week 16. CONCLUSIONS: CD34(+) cell therapy is feasible, safe and effective in slowing the decline of hepatic reserve function.
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Antígenos CD34 , Tratamiento Basado en Trasplante de Células y Tejidos/métodos , Factor Estimulante de Colonias de Granulocitos/administración & dosificación , Cirrosis Hepática/terapia , Trasplante de Células Madre de Sangre Periférica/métodos , Anciano , Autoinjertos , Estudios de Factibilidad , Femenino , Estudios de Seguimiento , Factor Estimulante de Colonias de Granulocitos/farmacología , Arteria Hepática , Células Estrelladas Hepáticas/parasitología , Venas Hepáticas/fisiopatología , Humanos , Inyecciones Subcutáneas , Circulación Hepática , Cirrosis Hepática/enzimología , Cirrosis Hepática/patología , Cirrosis Hepática/fisiopatología , Regeneración Hepática , Masculino , Metaloproteinasas de la Matriz/metabolismo , Persona de Mediana Edad , Estudios Prospectivos , Terapéutica , Factores de Tiempo , Presión VenosaRESUMEN
Activin E activates brown and beige adipocytes and has been controversially implicated as a factor that induces obesity and fatty liver. Here, we sought to address this controversial issue by producing recombinant human activin E to evaluate its effects on HB2 brown adipocytes in vitro. Activin E increased uncoupling protein 1 (Ucp1) and fibroblast growth factor 21 (Fgf21) mRNA expression in the adipocytes. This upregulation was suppressed by SB431542, an inhibitor of activin receptor-like kinase (Alk) TGF-ß type I receptors. SB431542 also inhibited the activin E-induced phosphorylation of Smad2/3. A promoter assay using a CAGA-Luc reporter and Alk expression vectors revealed that activin E activated the TGF-ß/activin pathway via Alk7. The upregulation of Ucp1 and Fgf21 mRNA might be mediated through Alk7 and Smad2/3 phosphorylation. Activin E is a potential stimulator of energy expenditure by activating brown adipocytes and highlights its potential as a therapeutic target for treating obesity.
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Background: We previously developed a risk-scoring system for heart failure (HF) in patients with acute myocardial infarction (MI), namely "HF time-points (HFTPs)". In the original HFTPs, the presence of HF on admission, during hospitalization, and at short-term follow-up was individually scored. This study examined whether the revised HFTPs, with additional scoring of previous HF, provide better predictivity. Methods: This multicenter registry included a total of 1331 patients with acute MI undergoing percutaneous coronary intervention. HF was evaluated at four time-points before and after acute MI onset: (1) a history of HF; (2) elevated natriuretic peptide levels on admission; (3) in-hospital HF events; and (4) elevated natriuretic peptide levels at a median of 31 days after the onset. When HF was present at each time-point, one point was assigned to a risk scoring system, namely the original and revised HFTPs, ranging from 0 to 3 and from 0 to 4. The primary endpoint was a composite of cardiovascular death and HF rehospitalization after discharge. Results: Of the 1331 patients, 65 (4.9%) had the primary outcome events during a median follow-up period of 507 (interquartile range, 335-1106) days. The increase in both original and revised HFTPs was associated with an increased risk of the primary outcomes in a stepwise fashion with similar diagnostic ability. Conclusions: The original and revised HFTPs were both predictive of long-term HF-related outcomes in patients with acute MI undergoing percutaneous coronary intervention. Yet, the original HFTPs may be sufficient to estimate HF risks after MI.
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Type A acute aortic dissection (AAD) is a fatal disease and thus, accurate and objective risk stratification is essential. In this study, we evaluated the prognostic value of readily available and assessable biomarkers in patients with type A AAD. This was a retrospective, multicenter, observational study. A total of 703 patients with type A AAD diagnosed using contrast-enhanced computed tomography were included. Therapeutic strategies were left to the physician's discretion in a real-world clinical setting. The prognostic value for in-hospital mortality was examined in 15 circulating biomarkers on admission, which are routinely available in clinical practice. Of the 703 patients, 126 (17.9%) died during the hospitalization. Of the 15 biomarkers, the multivariable analysis identified positive cardiac troponin, a low total bilirubin (T-Bil) level, and increased levels of brain natriuretic peptide (BNP) and lactate dehydrogenase (LDH) as significant predictors of in-hospital death. The receiver operating characteristics curve analysis showed that these 4 biomarkers had an independent additive prognostic value. With the cut-off values of T-Bil, BNP, and LDH, in combination with positive troponin, the increase in the number of positive biomarkers was progressively associated with higher in-hospital mortality from 1.3% to 9.8%, 20.5%, 36.4%, and 75.0% (p <0.001). In conclusion, in patients with type A AAD, positive cardiac troponin, a low T-Bil level, and increased levels of BNP and LDH on admission were related to higher in-hospital mortality, with an incremental prognostic value, suggesting that the readily available and assessable biomarkers can aid in decision-making in therapeutic strategies.
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Disección Aórtica , Humanos , Estudios Retrospectivos , Mortalidad Hospitalaria , Biomarcadores , Pronóstico , Disección Aórtica/diagnóstico , Péptido Natriurético Encefálico , Medición de Riesgo , TroponinaRESUMEN
Background: The lack of standard modifiable cardiovascular risk factors (SMuRFs), including hypertension, diabetes, dyslipidemia, and smoking, is reportedly associated with poor outcomes in acute myocardial infarction (AMI). Among patients with no SMuRFs, cancer and chronic systemic inflammatory diseases (CSIDs) may be major etiologies of AMI. Objectives: The purpose of this study was to evaluate clinical characteristics and outcomes of patients with cancer, CSIDs, and no SMuRFs in AMI. Methods: This multicenter registry included 2,480 patients with AMI undergoing percutaneous coronary intervention. Patients were divided into 4 groups: active cancer, CSIDs, no SMuRFs, and those remaining. The coprimary endpoint was major adverse cardiovascular events (MACE) and major bleeding events, during hospitalization and after discharge. Results: Of 2,480 patients, 104 (4.2%), 94 (3.8%), and 120 (4.8%) were grouped as cancer, CSIDs, and no SMuRFs, respectively. During the hospitalization, MACE rates were highest in the no SMuRFs group, followed by the cancer, CSIDs, and SMuRFs groups (22.5% vs 15.4% vs 12.8% vs 10.2%; P < 0.001), whereas bleeding risks were highest in the cancer group, followed by the no SMuRFs, CSIDs, and SMuRFs groups (15.4% vs 10.8% vs 7.5% vs 4.9%; P < 0.001). After discharge, the rates of MACE (33.3% vs 22.7% vs 11.3% vs 9.2%; P < 0.001) and bleeding events (8.6% vs 6.7% vs 3.8% vs 2.9%; P = 0.01) were higher in the cancer group than in the CSIDs, no SMuRFs, and SMuRFs groups. Conclusions: Patients with active cancer, CSIDs, and no SMuRFs differently had worse outcomes after AMI in ischemic and bleeding endpoints during hospitalization and/or after discharge, compared with those with SMuRFs.