J H Zhang

Publications (2)3.41 Total impact

• Article: Hydrogen sulfide induces apoptosis in human periodontium cells.

  J-H Zhang, Z Dong, L Chu
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  ABSTRACT: The existence of hydrogen sulfide (H(2)S) at high concentrations in periodontal pockets is a characteristic feature of periodontitis. Periodontal pathogens play a key role in the production of H(2)S under these etiology conditions. This study was designed to examine the cytotoxicity of H(2)S in periodontium cells, including human periodontal ligament (PDL) cells and human gingival fibroblasts (HGFs), as well as the role of H(2)S in apoptosis induction. Human PDL cells and HGFs were cultured in the presence of Na(2)S/HCl or in the presence of H(2)S produced enzymatically by the action of Treponema denticola cystalysin (l-cysteine desulfhydrase) on l-cysteine. Apoptosis was assessed morphologically after nuclear staining with DAPI or was quantified by flow cytometry after staining with annexin V. Caspase activation was measured by an enzymatic assay using DEVD-AMC, a synthetic caspase substrate. Among the three products obtained following degradation of l-cysteine by T. denticola cystalysin, only H(2)S induced significant apoptosis in HGF cells. Hydrogen sulfide also induced typical apoptotic morphology in cultured PDL cells. The changes were dependent on the H(2)S dose and on the treatment time with H(2)S. Hydrogen sulfide-induced apoptosis was also confirmed by staining with annexin V and propidium iodide. In addition, treatment with H(2)S led to caspase activation in these cells. These results showed that physiological concentrations of H(2)S can induce apoptosis of PDL cells and HGFs in periodontitis, suggesting that H(2)S may play an important role in periodontal tissue damage in periodontal diseases.
  Journal of Periodontal Research 08/2009; 45(1):71-8. · 1.69 Impact Factor
• Source

  Available from: iiar-anticancer.org

  Article: Bone sialoprotein promotes bone metastasis of a non-bone-seeking clone of human breast cancer cells.

  J H Zhang, J Wang, J Tang, B Barnett, J Dickson, N Hahsimoto, P Williams, W Ma, W Zheng, T Yoneda, S Pageau, J Chen
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  ABSTRACT: Bone sialoprotein (BSP) is a major non-collagenous protein in mineralized tissues. BSP is also implied to be involved in tumor metastasis through its unique structure. Using the human breast cancer cell line MDA-231, we established both brain-seeking and bone-seeking cell clones. The brain-seeking cells (MDA4-231BR) showed no bone metastasis in an animal model. In this experiment, MDA-231BR cells were transfected with BSP cDNA and inoculated into the hearts of nude mice. All five nude mice which received BSP-transfected MDA-231BR cells developed bone metastases, while no bone lesions were observed in the control group. Histological examination revealed invasion of tumor cells into the endosteal space and erosion of the bone margin. Some animals were crippled due to large lesions. These results suggest that BSP may impart to breast cancer cells the capacity to metastasize and thus play an important role in bone metastasis of malignant tumors.
  Anticancer research 24(3a):1361-8. · 1.73 Impact Factor