MMP-1 Over-expression Promotes Malignancy and Stem-Like Properties of Human Osteosarcoma MG-63 Cells In Vitro.

Osteosarcoma is the most common primary malignant bone tumor in childhood, and it maintains a high level of recurrence. Matrix metalloproteinase-1 (MMP-1) was found to contribute to cancer progression. The present study was to investigate the in vitro effects of MMP-1 over-expression on the proliferation, invasion, metastasis and stem-like properties of osteosarcoma MG-63 cells. The MG-63 cells were cultured and had a full length MMP-1 cDNA inserted by the lentiviral vector (MG-63MMP-1+). MG-63 negative control and MG-63 blank control groups were established as well. MMP-1 expression was detected in MG-63MMP-1+, MG-63 negative control and MG-63 blank control cells using qPCR, Western blotting and immunofluorescence after 24 h of culture. The cell proliferation assay was performed with a camera attached to a bioreactor, which was programmed to photograph five regions of each well every 10 min over a period of 48 h. The cell invasion assay was conducted with Matrigel to assess the invasive potential of MG-63 cells over 24 h, the qPCR analysis to measure stem cell markers, including Oct4, Sox-2, Nanog, and Pax-7, and Western blot analysis to detect invasive and metastatic potential markers TIMP-1, VEGF and BMP2/4, after 24 h of culture. Immunofluorescence was used to investigate the presence of the stem cell marker Pax-7 after 24-h culture. The results showed that over-expression of MMP-1 after transfection could significantly increase tumor cell proliferation and invasion (P<0.05, MG-63MMP-1+versus controls). Pax-7 was highly expressed in MG-63MMP-1+ cells, with no significant changes of Oct-4, Sox-2, and Nanog observed (P<0.05). MG-63MMP-1+ cells showed higher expression of VEGF and BMP 2/4 proteins and lower expression of TIMP-1 protein than controls (P<0.05). It was concluded that MMP-1 over-expression in MG-63 cells contributed to the proliferation, invasion, metastasis and stem-like properties of osteosarcoma cells. Future studies should focus on in vivo effects of MMP-1 over-expression and the application of MMP-1 and Pax-7 inhibition in vivo to osteosarcoma therapies.

Activation of BV2 microglia by lipopolysaccharide triggers an inflammatory reaction in PC12 cell apoptosis through a toll-like receptor 4-dependent pathway.

Microglia play an important role in neuronal protection and damage. However, the molecular and cellular relationship between microglia and neurons is unclear. We carried out a prospective study to detect that activation of BV2 microglia induced PC12 cell apoptosis in vitro through the TLR4/adapter protein myeloid differentiation factor 88 (MyD88)/nuclear factor-κB (NF-κB) signaling pathway. BV2 microglia were treated with different concentrations of LPS for 24 h. Western blot was utilized to detect the expression of TLR4 and the downstream signaling pathway. The level of inflammatory mediator was quantified using a specific ELISA kit. The supernatant of 10 µg/ml LPS-treated BV2 cells was used as conditioned medium (CM). PC12 cells were co-culture with CM for 24 h. Cell viability was determined by MTT assay and cell apoptosis was tested by flow cytometry. BV2 microglia were treated with 10, 20, or 30 µg/ml LPS for 24 h. The expression of TLR4, MyD88, and NF-κB significantly increased. When PC12 cells were co-cultured with CM for 24 h, cell viability decreased. CM up-regulated the Bax level and down-regulated the Bcl-2 protein level in PC12 cells. PC12 cells pretreated with interleukin-1 receptor antagonist (IL-1RA) for 30 min, significantly alleviated CM-induced PC12 cell apoptosis. These results suggest that BV2 microglia activated by LPS triggered TLR4/MyD88/NF-κB signaling pathway that induced the release of IL-1ß and could participate in the PC12 cells injury.

TLR4 signaling is involved in the protective effect of propofol in BV2 microglia against OGD/reoxygenation

Propofol exhibits neuroprotective effects against hypoxic–ischemic brain injury, but the underlying mechanisms are still not clear. Toll-like receptor 4 (TLR4) plays a considerable role in the induction of innate immune and inflammatory responses. The purposes of this study are to investigate the effect of propofol on the oxygen and glucose deprivation (OGD)/reoxygenation (OGD/R) BV2 microglia and to explore the role of TLR4/myeloid differentiation protein 88 (MyD88)/nuclear factor-kappa B (NF-KappaB) pathway in the neuroprotective effects of propofol. BV2 microglia were placed into an airtight chamber and in glucose-free medium for OGD/reoxygenation. Cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide assay. TLR4 and its downstream signaling molecules, MyD88 and NF-KappaB expressions were detected by Western blotting. Level of tumor necrosis factor alpha (TNF-Alpha) in culture medium was determined with enzyme-linked immunosorbent assay. BV2 microglia apoptosis was determined by flow cytometry. We found that pretreatment with propofol significantly alleviated the hypoxic injury in BV2 microglia. Propofol inhibited upregulation of TLR4, MyD88, and NF-KappaB expressions in BV2 microglia exposed to OGD/reoxygenation. Propofol pretreatment also significantly reduced the production of TNF-Alpha and apoptosis in OGD/reoxygenation BV2 microglia. The results indicated that TLR4 and its downstream MyD88-dependent signaling pathway contributed to neuroprotection of propofol to microglia exposed to OGD/reoxygenation

Propofol inhibits hypoxia/reoxygenation-induced human gastric epithelial cell injury by suppressing the Toll-like receptor 4 pathway.

This study aimed to investigate the role of the Toll-like receptor 4 (TLR4) pathway in normal human gastric epithelial (GES-1) cells under hypoxia/reoxygenation (H/R) in vitro, and the effect of propofol on injured GES-1 cells as well as its possible mechanism. Before H/R induction, GES-1 cells were preconditioned with fat emulsion, propofol, or epigallocatechin gallate. Then cell viability, cell apoptosis, and related molecules in the cells were analyzed under experimental conditions. We found that propofol 50 µmol/L markedly inhibited the H/R injury under hypoxia 1.5 h/reoxygenation 2 hours by promoting GES-1 cell viability and decreasing cell apoptosis. The TLR4 signal may be involved in the protective effect of propofol against H/R injury. The malondialdehyde contents and superoxide dismutase activities were recovered under propofol preconditioning. In summary, propofol preconditioning may exert a protective effect on H/R injury in GES-1 cells and the mechanism may be via inhibition of the activated TLR4 signal under H/R conditions.

TLR4 signaling is involved in the protective effect of propofol in BV2 microglia against OGD/reoxygenation.

Propofol exhibits neuroprotective effects against hypoxic-ischemic brain injury, but the underlying mechanisms are still not clear. Toll-like receptor 4 (TLR4) plays a considerable role in the induction of innate immune and inflammatory responses. The purposes of this study are to investigate the effect of propofol on the oxygen and glucose deprivation (OGD)/reoxygenation (OGD/R) BV2 microglia and to explore the role of TLR4/myeloid differentiation protein 88 (MyD88)/nuclear factor-kappa B (NF-κB) pathway in the neuroprotective effects of propofol. BV2 microglia were placed into an airtight chamber and in glucose-free medium for OGD/reoxygenation. Cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide assay. TLR4 and its downstream signaling molecules, MyD88 and NF-κB expressions were detected by Western blotting. Level of tumor necrosis factor alpha (TNF-α) in culture medium was determined with enzyme-linked immunosorbent assay. BV2 microglia apoptosis was determined by flow cytometry. We found that pretreatment with propofol significantly alleviated the hypoxic injury in BV2 microglia. Propofol inhibited upregulation of TLR4, MyD88, and NF-κB expressions in BV2 microglia exposed to OGD/reoxygenation. Propofol pretreatment also significantly reduced the production of TNF-α and apoptosis in OGD/reoxygenation BV2 microglia. The results indicated that TLR4 and its downstream MyD88-dependent signaling pathway contributed to neuroprotection of propofol to microglia exposed to OGD/reoxygenation.

Toll-like receptor 4 signaling is involved in PACAP-induced neuroprotection in BV2 microglial cells under OGD/reoxygenation.

OBJECT: The neuroprotective effects of pituitary adenylate cyclise-activating polypeptide (PACAP) have been well documented in vivo and in vitro. However, the mechanisms by which PACAP protected microglia from ischemic/hypoxic injury via inhibition of microglia activation remain unclear. Toll-like receptor 4 (TLR4) plays a considerable role in the induction of innate immune and inflammatory responses. The purpose of this study is to investigate the effect of PACAP on the oxygen and glucose deprivation (OGD)/reoxygenation BV2 microglia and to explore the role of TLR4/myeloid differentiation protein 88 (MyD88)/nuclear factor-kappa B (NF-kappaB) pathway in the neuroprotective effects of PACAP. METHODS: We conducted OGD/reoxygenation by placing BV2 microglia into an airtight chamber and in glucose-free medium. BV2 microglia cell viability was determined by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide] assay. Western blot was utilized to detect TLR4, MyD88 expression, inhibitory protein of NF-kappaB (IkappaB) phosphorylation/degradation, NF-kappaB activation. Level of tumor necrosis factor-alpha (TNF-alpha) in culture medium was measured with enzyme-linked immunosorbent assay (ELISA). Apoptosis was determined by flow cytometry. RESULTS: We found that pretreatment with PACAP to BV2 cells immediately before OGD/reoxygenation significantly alleviated microglia hypoxic injury. PACAP inhibited upregulation of TLR4, MyD88 and NF-kappaB in BV2 microglial cells exposed to OGD/reoxygenation. PACAP administration also significantly reduced the production of proinflammatory cytokines and apoptosis in BV2 microglia exposed to OGD/reoxygenation. DISCUSSION: Pretreatment with PACAP inhibited activation of the TLR4/MyD88/NF-kappaB signaling pathway and decreased inflammatory cytokine levels, as well as apoptosis in microglia, thereby attenuating microglia hypoxic injury. Our results suggested that TLR4-mediated MyD88-dependent signaling pathway contributed to neuroprotection of PACAP to microglia against OGD/reoxygenation.

LC/MS guided isolation of alkaloids from lotus leaves by pH-zone-refining counter-current chromatography.

The traditional methods used in natural product separation primarily target the major components and the minor components may thus be lost during the separation procedure. Consequently, it's necessary to develop efficient methods for the preparative separation and purification of relatively minor bioactive components. In this paper, a LC/MS method was applied to guide the separation of crude extract of lotus (Nelumbo nucifera Gaertn.) leaves whereby a minor component was identified in the LC/MS analysis. Afterwards, an optimized pH-zone-refining CCC method was performed to isolate this product, identified as N-demethylarmepavine. The separation procedure was carried out with a biphasic solvent system composed of hexane-ethyl acetate-methyl alcohol-water (1:6:1:6, v/v) with triethylamine (10 mM) added to the upper organic phase as a retainer and hydrochloric acid (5 mM) to the aqueous mobile phase eluent. Two structurally similar compounds--nuciferine and roemerine--were also obtained from the crude lotus leaves extract. In total 500 mg of crude extract furnished 7.4 mg of N-demethylarmepavine, 45.3 mg of nuciferine and 26.6 mg of roemerine with purities of 90%, 92% and 96%, respectively. Their structures were further identified by HPLC/ESI-MSn, FTICR/MS and the comparison with reference compounds.

[Angiotensin-converting enzyme gene and the brachial artery endothelial dysfunction in type 2 diabetes without angiopathy].

OBJECTIVE: To investigate the relationship between angiotensin converting enzyme (ACE) gene and endothelial dysfunction. METHODS: One hundred and ten type 2 diabetic patients without angiopathy were selected randomly, and PCR technique was used to determine their ACE genotypes. High resolution ultrasonography was performed to measure the changes in brachial artery diameter at rest, after reactive hyperemia (with increased flow producing an endothelium-dependent dilation) and after sublingual glyceryltrinitrate (GNT, an endothelium-independent dilator). Meanwhile, 50 healthy individuals were selected randomly as controls. RESULTS: In type 2 diabetes mellitus and control groups, the percentages for flow-mediated arterial dilation in patients with DD genotypes were 3.38% and 3.67% respectively, which were significantly lower than those in patients with II genotypes (4.12% and 4.68% respectively, P<0.05). The baseline blood vessel size, baseline blood flow and GNT induced dilation in both groups showed no significant differences among ACE genotypes (P>0.05). By multiple stepwise regression analysis, reduced flow-mediated arterial dilation was associated with age, baseline vessel size, low density lipoprotein cholesterol(LDL-C), Lp(a), D allele, fasting blood glucose (FBG), postparandial blood glucose (PPBG), HbA1c, duration of diabetes in type 2 diabetic patients (P<0.0005). CONCLUSION: ACE DD genotype is related to endothelium-dependent arterial dilation in the early stage of type 2 diabetes mellitus and in healthy individuals.

A clinical evaluation of serological diagnosis for pancreatic cancer.

AIM:To assess the diagnostic values of tumor markers for pancreatic cancer.METHODS:Pancreatic cancer-associated antigen from colonic mucosa (PCAAc), pancreas-specific antigen (PaA), pancreatic oncofetal antigen (POA) and minimolecular pancreatic antigen (mPOA) were detected by double antibodies Sandwich ELISA; CA19-9,elastase 1 (E1), human pancreatic elastase 1 (HPE1) and carcinoembryonic antigen (CEA) by radioimmunoassay (RIA); general activities of ribo-nuclease (RNase) and its isoenzymes (RNase I and RNase I) by biochemistry and PAEG;glycylproline dipeptidyl aminopeptidase (GPDA) by biochemistry andalpha 1-antitrypsin (alpha1AT) by rocket immunoelectrophoresis (rocket-IE).RESULTS:The detection of serum POA,mPOA,PaA,PCAAc,CA19-9,RNase and RNase I was able to differentiate pancreatic cancer from the benign disorders and non-pancreatic malignancies with a sensitivity from 66.75% to 80.0% and a specificity from 88.5% to 96.69%. POA, mPOA, PCAAc, HPE1, E1 and GPDA were related to the pancreatic cancer at the head which demonstrated higher sensitivity from 63.64% to 85.71%. The detection of serum HPE1 was especially helpful for the diagnosis of pancreatic cancer with smaller diameters. The determination of 3 or 4 kinds of tumor markers simultaneously would increase the detection rate of pancreatic cancer, which will be an important procedure for the diagnosis of this malignancy.CONCLUSION:A single test of tumor markers is helpful to detect pancreatic cancer clinically,but the determination of 3 or 4 kinds of tumor markers simultaneously would significantly increase the detection rate of pancreatic cancer, which will be an important procedure for the diagnosis of this malignancy.