RESUMO
BACKGROUND: As a bioactive composite extracted from American cockroach, Xinmailong injection (XML) is used for the treatment of congestive heart failure (CHF) in China. Clinical data has provided evidence that XML has positive inotropic properties. The objective of this study was to assess the mechanisms involved in the therapeutical effect of XML on CHF. MATERIALS AND METHODS: The effects of XML on the cardiac function in isolated rat heart were measured. A Ca2+ imaging technology was used in rat cardiomyocytes (H9c2 cells) to reveal the role of XML on Ca2+ channels. Meanwhile, the effects of XML on the activities of Na+/K+ ATPase and sodium/calcium exchanger were measured. In addition, the level of reactive oxygen species and the protein expressions for the superoxide dismutase and hemeoxygenase were determined in the cardiomyocytes. RESULTS: The results showed that XML increased the electrical impulse-induced [Ca2+]i in H9c2 cells, which was dependant on extracellular Ca2+ and was abolished by ML218-HCl (a T-type Ca2+channels antagonist) but not nimodipine (a L-type Ca2+channels antagonist). Ouabain, a Na+/K+-ATPase inhibitor, increased the electrical impulse-induced [Ca2+]i, which was significantly inhibited by XML. Moreover, XML markedly inhibited the Na+/K+ ATPase activity in H9c2 cells. In addition, XML notably reduced the production of reactive oxygen species and enhanced the protein expressions of antioxidant enzymes including superoxide dismutase 1, superoxide dismutase 2 and hemeoxygenase 1 in H9c2 cell. CONCLUSION: Our findings pave the ways to the better understandings of the therapeutic effects of XML on cardiovascular system.
Assuntos
Canais de Cálcio/metabolismo , Cálcio/metabolismo , Medicamentos de Ervas Chinesas/farmacologia , Coração/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Animais , Compostos Azabicíclicos/farmacologia , Benzamidas/farmacologia , Bloqueadores dos Canais de Cálcio/farmacologia , Cardiotônicos/farmacologia , Linhagem Celular , Baratas/química , Coração/fisiologia , Heme Oxigenase-1/metabolismo , Medicina Tradicional Chinesa , Miócitos Cardíacos/metabolismo , Nimodipina/farmacologia , Ouabaína/farmacologia , Ratos , Espécies Reativas de Oxigênio/metabolismo , Trocador de Sódio e Cálcio/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Superóxido Dismutase/metabolismoRESUMO
Giant cell tumor of bone (GCT) is the most commonly reported non-malignant bone tumor in Hong Kong. This kind of tumor usually affects people aged 20-40 years. Also, it is well known for recurrence locally, especially when the tumor cannot be removed completely. Filamins are actin-binding proteins which contain three family members, filamin A, B and C. They are the products of three different genes, FLNA, FLNB and FLNC, which can generate various transcript variants in different cell types. In this study, we focused on the effects of FLNBv2 and FLNBv4 toward GCT cells. The only difference between FLNBv2 and FLNBv4 is that FLNBv4 does not contain hinge 1 region. We found that the relative abundance of FLNBv4 varies among different GCT cell lines while the expression level of FLNBv4 in normal osteoblasts was only marginally detectable. In the functional aspect, overexpression of FLNBv4 led to upregulation of RANKL, OCN, OPG and RUNX2, which are closely related to GCT cell survival and differentiation. Moreover, FLNBv4 can have a negative effect on cell viability of GCT cells when compare with FLNBv2. In conclusion, splicing variants of FLNB are differentially expressed in GCT cells and may play a role in the proliferation and differentiation of tumor cells.
Assuntos
Neoplasias Ósseas/metabolismo , Filaminas/genética , Regulação Neoplásica da Expressão Gênica , Expressão Gênica , Tumor de Células Gigantes do Osso/metabolismo , Adolescente , Adulto , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Neoplasias Ósseas/genética , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Feminino , Filaminas/metabolismo , Tumor de Células Gigantes do Osso/genética , Humanos , Masculino , Pessoa de Meia-Idade , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Células Tumorais Cultivadas , Adulto JovemRESUMO
Danshen (Radix Salviae miltiorrhizae) and ChuanXiong (Ligusticum wallichii) are two traditional herbal medicines commonly used in China for the treatment of cardiovascular diseases. The active components in Danshen and ChuanXiong are Danshensu (DSS, (R)-3, 4-dihydroxyphenyllactic acid) and tetramethylpyrazine (TMP), respectively. In the present study, a new compound named ADTM, which is a conjugation of DSS and TMP, was synthesized and its effect on the contractility of rat mesenteric arteries was examined. The relaxation effect of ADTM on rat mesenteric arteries was studied using myography. The effects of ADTM on Ca(2+) channels were measured by Ca(2+) imaging and patch-clamp techniques. The results showed that ADTM caused a concentration-dependent relaxation of rat mesenteric arteries. This relaxation effect was not affected by the removal of endothelium or inhibitors of nitric oxide synthase, cyclooxygenase, guanylyl cyclase and adenylyl cyclase. Potassium channel blockers including tetraethylammonium, iberiotoxin, apamin, 4-aminopyridine, BaCl2 and glibenclamide also failed to inhibit the relaxation response to ADTM. ADTM inhibited CaCl2-induced contractions and reduced the Ca(2+) influx in isolated mesenteric arterial muscle cells. Our results suggest that ADTM may be a novel relaxing agent. Its mechanism of action involves the direct blockade of voltage-gated Ca(2+) channels in vascular smooth muscle cells, resulting in a decrease in Ca(2+) influx into the cells.
