BCA (Disodium bicinchoninate)

Fabrication of succinate-alginate xerogel films for in vitro coupling of osteogenesis and neovascularization

The osseointegration of metallic implants is reliant on a cascade of molecular interactions and the delivery of macromolecules to the implant environment that occurs before substantial bone formation. Early blood vessel formation is a requisite first step in the healing timeline for osteoid formation, where vascular development can be accelerated as a result of controlled hypoxic conditioning. In this study, alginate-derived xerogel films containing varied concentrations of disodium succinate salt which has been shown to induce pseudohypoxia (short-term hypoxic effects while maintaining an oxygenated environment) were developed. Xerogels were characterized for their morphology, succinate release over time and cellular response with osteoblast-mimicking Saos-2 and human umbilical vein endothelial cells (HUVEC). Scanning electron microscopy revealed a multiscale topography that may favour osseointegration and alamarBlue assays indicated no cytotoxic effects during in vitro proliferation of Saos-2 cells. pH measurements of eluted succinate reach 95 % of peak value after 7 h of immersion for all gels containing 10 mM of succinate or less, and 60 % within the first 40 min. In vitro exposure of HUVECs to succinate-conditioned media increased the net concentration of total proteins measured by bicinchoninic acid (BCA) assay and maintains stable vascular endothelial growth factor (VEGF) and extracellular platelet-derived growth factor (PDGF) for vessel formation through comparison of enzyme-linked immunosorbent assays (ELISAs) of the culture media and cell lysate. Tube formation assays also showed a sustained increase in tube diameter across the first 48 h of HUVEC culture when succinate concentrations of 1 and 10 μM in the xerogel. Overall, the succinate-alginate films serve as a prospective organic coating for bone-interfacing implant materials which may induce temporary pseudohypoxic conditions favourable for early angiogenesis and bone regeneration in vivo at succinate concentrations of 1 or 10 μM.

Differentiation of bel-7402 human hepatocarcinoma cells induced by aqueous extracts of fresh gecko (AG) and its anti-tumor activity in vivo

Ethnopharmacological relevance: Gecko, a kind of reptile, has been widely used as a traditional Chinese medicine to treat various diseases including cancer in China for thousands of years. The aim of this study was to investigate the anti-tumor effect of AG (aqueous extracts of fresh gecko) on human hepatocellular carcinoma cell Bel-7402 in vitro and mouse H22 hepatocellular in vivo. Further to underlie the molecular mechanism of AG inducing the differentiation of Bel-7402 cells.
Materials and methods: AG was obtained by water extracting method and qualitatively analyzed through High Performance Liquid Chromatography. The total protein concentration of AG was measured by BCA (bicinchoninic acid disodium) assay. The anti-tumor activities in vivo were analyzed through H22 (mouse hepatocellular carcinoma cell line H22) tumor xenografts mice. The cytotoxic activity of AG on Bel-7402 cells was evaluated by MTT assays. AFP (alpha fetoprotein) was detected by radioimmunoassay. ALB (albumin), ALP (alkaline phosphatase) and γ-GT (γ-glutamyl transpeptidase) were detected by biochemical methods with commercial kits. While morphological changes were observed through an inverted microscope. Moreover, the expression level of the proteins involved in MAPK (mitogen-activated protein kinase) signal pathway which was closely related to cellular differentiation was assessed by Western blot.
Results: AG showed obviously anti-tumor activity in vivo and anti-proliferative activity on Bel-7402 cells in vitro both dose-dependently. The number of clones of Bel-7402 cells treated with AG reduced and the cells were displaying differentiation state such as relatively bigger size and dispersed growth. The biochemical function markers of the cells were significantly changed after being treated with AG. The data showed that AFP secretion of the cells decreased 42.5%, ALB secretion increased 58.9%, the activity of ALP and γ-GT markedly decreased 67.0% and 48.5% separately when the concentration of AG was 10μl/ml, and those effects were all in a dose-dependent manner. The major original and phosphorylated signal proteins (ERK1/2 (extracellular sigal-regualted kinase 1/2), P38 (p38 MAPK) and JNK1/2 (c-Jun N-terminal kinase 1/2)) involved in MAPK signal pathway were measured and the results showed that AG activated the ERK1/2 of Bel-7402 cells.
Conclusions: AG has anti-tumor activity in vivo and inhibits Bel-7402 cell proliferation in vitro through inducing cell differentiation, and the mechanism involves the activation of ERK1/2.

Huang-Lian-Jie-Du-Decotion induced protective autophagy against the injury of cerebral ischemia/reperfusion via MAPK-mTOR signaling pathway

Ethnopharmacological relevance: Huang-Lian-Jie-Du-Decotion (HLJDD, Hwangryun-Hae-Dok-Decotion in Japan), an ancient antipyretic and detoxifying traditional Chinese medicine formula, was reported to have protective effect on ischemic stroke.
Aim of the research: To investigate the therapeutic effect of HLJDD on ischemic stroke and explore its mode of action.
Material and methods: A model of ischemic stroke in the rat was established after transient middle cerebral artery occlusion (MCAO) followed by reperfusion. Rats were assigned randomly to groups of control, sham, transient ischemia/reperfusion (I/R), and three treatment groups by HLJDD at 2.5, 5.0, 10.0mg/kg. The neurological deficit, the cerebral infarct size, morphology abnormality, biochemical parameters were examined, and the levels of relevant proteins were determined by immunoblotting analysis to evaluate the protective effects of HLJDD on ischemic stroke and explore the underlying mechanism.
Results: Compared with I/R group, HLJDD significantly ameliorated neurological deficit and histopathology changes, decreased infarct area, and restored the levels of biochemical indicators including nitric oxide (NO), malondialdehyde (MDA), glutathione (GSH), glutathione disulfide (GSSG), total superoxide dismutase (T-SOD), Cu/Zn-SOD, Mn-SOD and glutathione peroxidase (GSH-PX). HLJDD also notably elevated the levels of microtubule-associated protein 1 light chain 3 (LC3), Beclin-1, and other autophagy related genes (Atgs), promoted the activation of extracellular signal-regulated kinases (ERK), protein kinase B (Akt), 3-phosphoinositide-dependent kinase (PDK1), and inhibited the activation of mammalian target of rapamycin (mTOR), c-Jun N-terminal protein kinases (JNK), p38, phosphatase and tensin homolog (PTEN).
Conclusion: HLJDD showed neuroprotective effects on ischemic stroke, at least in part to the induced protective autophagy via the regulation of mitogen-activated protein kinase (MAPK) signals. This Akt-independent protective autophagy is favorable in the treatment of stroke, avoiding unfavorable side-effects associated with the inactivation of Akt. The efficacy of HLJDD on ischemic stroke and its safety warranted by its long-term clinical use in traditional Chinese medicine favored further study to develop HLJDD as an effective therapeutic agent to treat ischemic stroke.