RESUMO
Glucocorticoid (GC)-induced osteoporosis (GIO) is characterized by impaired bone formation, which can be alleviated by tanshinol, an aqueous polyphenol isolated from Salvia miltiorrhiza Bunge. In this study we investigated the molecular mechanisms underlying GC-induced modulation of osteogenesis as well as the possibility of using tanshinol to interfere with GIO. Female SD rats aged 4 months were orally administered distilled water (Con), prednisone (GC, 5 mg·kg-1·d-1), GC plus tanshinol (Tan, 16 mg·kg-1·d-1) or GC plus resveratrol (Res, 5 mg·kg-1·d-1) for 14 weeks. After the rats were sacrificed, samples of bone tissues were collected. The changes in bone formation were assessed using Micro-CT, histomorphometry, and biomechanical assays. Expression of Kruppel-like factor 15 (KLF15), peroxisome proliferator-activated receptor γ 2 (PPARγ 2) and other signaling proteins in skeletal tissue was measured with Western blotting and quantitative RT-PCR. GC treatment markedly increased the expression of KLF15, PPARγ2, C/EBPα and aP2, which were related to adipogenesis, upregulated FoxO3a pathway proteins (FoxO3a and Gadd45a), and suppressed the canonical Wnt signaling (ß-catenin and Axin2), which was required for osteogenesis. Thus, GC significantly decreased bone mass and bone quality. Co-treatment with Tan or Res effectively counteracted GC-impaired bone formation, suppressed GC-induced adipogenesis, and restored abnormal expression of the signaling molecules in GIO rats. We conclude that tanshinol counteracts GC-decreased bone formation by inhibiting marrow adiposity via the KLF15/PPARγ2/FoxO3a/Wnt pathway.
Assuntos
Adipogenia/efeitos dos fármacos , Ácidos Cafeicos/uso terapêutico , Osteogênese/efeitos dos fármacos , Osteoporose/tratamento farmacológico , Via de Sinalização Wnt/efeitos dos fármacos , Adipócitos/metabolismo , Animais , Peso Corporal/efeitos dos fármacos , Medula Óssea/metabolismo , Proteína alfa Estimuladora de Ligação a CCAAT/genética , Regulação para Baixo , Proteínas de Ligação a Ácido Graxo/genética , Feminino , Proteína Forkhead Box O3/genética , Fatores de Transcrição Kruppel-Like/genética , PPAR gama/genética , Prednisona/administração & dosagem , Prednisona/farmacologia , Ratos Sprague-Dawley , Resveratrol , Estilbenos/administração & dosagem , Estilbenos/farmacologia , Regulação para Cima , Via de Sinalização Wnt/genéticaRESUMO
Acylation conducted by acyltransferase is a ubiquitous process in structure modification of secondary metabolites. It plays an important role in the structural diversity of natural products and contributes significantly to their improved stabilities, increased solubilities, and enhanced bioavailabilities. BAHD acyltransferase family is a typical kind of acyltransferase original from plants, which involved in the biosynthesis of various bioactive acylated natural products. In order to provide references for future investigations of BAHD acyltransferase family, research progresses on basic properties, three-dimensional structures, catalytic mechanisms, enzymatic functional identifications and phylogenetic analyses of BAHD family from plants is summarized in this paper.
Assuntos
Aciltransferases , Plantas/enzimologia , Filogenia , Metabolismo SecundárioRESUMO
Selective iodide uptake and prolonged iodine retention in the thyroid is the basis for targeted radioiodine therapy for thyroid cancer patients; however, salivary gland dysfunction is the most frequent nonthyroidal complications. In this study, we have used noninvasive single photon emission computed tomography functional imaging to quantify the temporal dynamics of thyroidal and salivary radioiodine accumulation in mice. At 60â min post radionuclide injection, radionuclide accumulation in the salivary gland was generally higher than that in thyroid due to much larger volume of the salivary gland. However, radionuclide accumulation per anatomic unit in the salivary gland was lower than that in thyroid and was comparable among mice of different age and gender. Differently, radionuclide accumulation per anatomic unit in thyroid varied greatly among mice. The extent of thyroidal radioiodine accumulation stimulated by a single dose of exogenous bovine TSH (bTSH) in triiodothyronine (T3)-supplemented mice was much less than that in mice received neither bTSH nor T3 (nontreated mice), suggesting that the duration of elevated serum TSH level is important to maximize thyroidal radioiodine accumulation. Furthermore, the extent and duration of radioiodine accumulation stimulated by bTSH was less in the thyroids of the thyroid-targeted RET/PTC1 (thyroglobulin (Tg)-PTC1) mice bearing thyroid tumors compared with the thyroids in wild-type (WT) mice. Finally, the effect of 17-allyamino-17-demothoxygeldanamycin on increasing thyroidal, but not salivary, radioiodine accumulation was validated in both WT mice and Tg-PTC1 preclinical thyroid cancer mouse model.
Assuntos
Benzoquinonas/farmacologia , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Lactamas Macrocíclicas/farmacologia , Glândulas Salivares/diagnóstico por imagem , Glândula Tireoide/diagnóstico por imagem , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Animais , Modelos Animais de Doenças , Imageamento Tridimensional , Camundongos , Receptores Patched , Receptor Patched-1 , Receptores de Superfície Celular/fisiologia , Tireotropina/farmacologiaRESUMO
AIM: Previous studies have shown that D(+)beta-3,4-dihydroxyphenyl lactic acid (salvianic acid A, SAA) has anabolic effects on prednisone (GC)-induced osteoporosis in rats. The current study aims to investigate the molecular mechanism of SAA's impact on osteogenesis and adipogenesis in bone marrow stromal cells in intact and GC-treated rats. METHODS: For in vitro study, newborn rat calvaria osteoblasts (rOBs) and rat bone marrow stromal cells (rMSCs) were isolated, identified and cultured with SAA at different concentrations to evaluate SAA's influence on osteogenesis and adipogenesis. In addition, 3-month-old Sprague-Dawley (SD) male rats were treated with distilled water, prednisone alone (3.0 mgxkg(-1)xd(-1)) or prednisone (3.0 mgxkg(-1)xd(-1)) and SAA (25 mgxkg(-1)xd(-1)) for 45 d. At the end point, the different groups of rMSCs were isolated by density-gradient centrifugation and cultured. RESULTS: (1) At 0.1-10.0 mg/L, SAA increased ALP activity, type I collagen (Coll-I) mRNA and OPG mRNA expression and stimulated nodule mineralization of rOBs. SAA (0.5 mg/L) also significantly increased the ALP activity of rMSCs without a need for osteogenesis-inducing medium. At 5.0 mg/L, SAA decreased the number of adipocytes with less lipid droplet formation from the rMSCs, which typically undergo adipocyte induction. (2) Coll-I expression was markedly decreased, whereas lipoprotein lipase (LPL) mRNA expression increased by 98% when compared with the first generation of rMSCs in GC-treated rats. The SAA-treated rats demonstrated an over 2-fold increase in Coll-I expression when compared with intact rats and further showed a significant decrease in LPL expression when compared with GC-treated rats. When rMSCs were co-cultured with SAA (0.5 mg/L) in vitro, SAA did not affect Coll-I and LPL gene expression in intact rats but significantly increased Coll-I and decreased LPL gene expression in GC-treated rats. CONCLUSION: SAA protected bone from GC-induced bone marrow impairment by stimulating osteogenesis and depressing adipogenesis in bone marrow stromal cells both in vivo and in vitro. The data indicated that aqueous extract of Salvia miltiorrhiza, which include SAA, may serve as an active anabolic agent and a useful therapeutic strategy for the treatment of GC-associated osteoporosis.
Assuntos
Células da Medula Óssea/efeitos dos fármacos , Ácidos Cafeicos/farmacologia , Glucocorticoides/farmacologia , Lactatos/farmacologia , Osteogênese/efeitos dos fármacos , Prednisona/farmacologia , Células Estromais/efeitos dos fármacos , Fosfatase Alcalina/metabolismo , Animais , Animais Recém-Nascidos , Células da Medula Óssea/citologia , Células da Medula Óssea/fisiologia , Diferenciação Celular/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Células Cultivadas , Colágeno Tipo I/genética , Colágeno Tipo I/metabolismo , Medicamentos de Ervas Chinesas/farmacologia , Lipase Lipoproteica/genética , Lipase Lipoproteica/metabolismo , Masculino , Estrutura Molecular , Osteocalcina/metabolismo , Extratos Vegetais/química , Ratos , Ratos Sprague-Dawley , Salvia/química , Células Estromais/citologia , Células Estromais/fisiologiaRESUMO
AIM: To investigate the skeletal effects of total tanshinone in ovariectomized rats by analyzing cancellous bone histomorphometry of fourth lumbar vertebrae (LV4) and proximal tibial metaphyses (PTM). METHODS: Four-month-old Sprague-Dawley female rats were sham-operated and treated with vehicle or ovariectomized and treated with either vehicle, total tanshinone (200 mg x kg(-1) x d(-1), equivalent to 35 microg x kg(-1) x d(-1) of tanshinone II A and 16 microg x kg(-1) x d(-1) of cryptotanshinone), or 17alpha-ethynylestradiol (30 microg x kg(-1) x d(-1) as positive treatment group) starting one day post-surgery for 10 weeks. Double in vivo fluorochrome labeling was administered to all rats. The undecalcified longitudinal LV4 and PTM sections were cut and stained with Goldner's Trichrome (4-microm thickness) or unstained (8-microm thickness) for the bone histomorphometric analysis. RESULTS: A significant decrease in trabecular bone volume (BV/TV) and trabecular number (Tb.N) and a significant increase in osteoclast surface (OCS/BS) and mineralizing surface (MS/BS) were found in both LV and PTM of vehicle-treated OVX rats compared with sham controls. Tanshinone completely prevented the decreases in BV/TV and Tb.N and the increase in OCS/BS in the LV4, and partially prevented the decreases in BV/TV and Tb.N in the PTM of OVX rats. In addition, tanshinone increased trabecular thickness (Tb.Th) whereas it did not alter MS/BS. Moreover, tanshinone had no effect on uterine weight and body weight of OVX rats. Estrogen treatment increased BV/TV and Tb.N and decreased OCS/BS, but, also markedly decreased MS/BS and increased uterine weight in OVX rats. CONCLUSION: The current study demonstrated that the adequate supply of tanshinone prevented OVX-induced cancellous bone loss in rats through inhibition of elevated bone resorption.
Assuntos
Reabsorção Óssea/prevenção & controle , Medicamentos de Ervas Chinesas/farmacologia , Etinilestradiol/análogos & derivados , Fenantrenos/farmacologia , Abietanos , Animais , Peso Corporal/efeitos dos fármacos , Densidade Óssea/efeitos dos fármacos , Etinilestradiol/farmacologia , Feminino , Vértebras Lombares/anatomia & histologia , Vértebras Lombares/efeitos dos fármacos , Tamanho do Órgão/efeitos dos fármacos , Osteoclastos/efeitos dos fármacos , Ovariectomia , Ratos , Ratos Sprague-Dawley , Tíbia/anatomia & histologia , Tíbia/efeitos dos fármacos , Útero/anatomia & histologia , Útero/efeitos dos fármacosRESUMO
AIM: To determine whether low dose of estrogen in combination with ginsenosides can completely prevent bone loss in ovariectomized rats. METHODS: Four-month-old ovariectomized rats were treated either with 100 and 300 mg.kg-1 of ginsenosides or 30 and 100 micrograms.kg-1 of 17 alpha-ethynylestradiol alone, or ginsenosides 100 mg.kg-1 in combination with 17 alpha-ethynylestradiol 30 micrograms.kg-1 for 10 weeks. Double in vivo fluorochrome labeling was made. The undecalcified longitudinal proximal tibial metaphyseal sections were processed and stained with Goldner's trichrome for histomorphometric analysis of the bone. RESULTS: Body weights and serum cholesterol were increased in ovariectomized (OVX) rats. The rats lost 74% of bone volume and high bone turnover was induced after OVX compared with the sham group. Bone volume increased by 205% in the high dose estrogen treated group while it was increased by 105% in the low dose group. The two doses of estrogen were shown to inhibit osteoclasts surface (by -65% and -55%, P < 0.01) and decrease bone turnover rate (by -85% and -83%, P < 0.01). High dose of estrogen was found to inhibit growth and stimulate uterine weight gain in rats while low dose did not. High dose of ginsenosides increased bone volume by 84% (P < 0.01) and decreased bone turnover rate by -64% (P < 0.05) while lower dose of ginsenosides did not. However, low dose ginsenosides combined with low dose estrogen achieved well preventive effects: increase of 202% in bone volume, decrease of 66% in bone turnover rate and 72% in osteoclasts surface. The combined effect in preventing bone loss equals to that the high dose of estrogen alone did. CONCLUSION: Use of low dose of estrogen plus ginsenosides showed synergistic effect on prevention of osteoporosis induced by ovariectomy.