[Effect of bone morphogenetic protein-2 on human heart valve interstitial cells calcification in vitro].

OBJECTIVE: To establish human heart valve interstitial cells calcification culture model in vitro, and observe the effect of bone morphogenetic protein-2 (BMP-2) on calcification of human heart valve interstitial cells. METHODS: Human heart valve interstitial cells were cultured in vitro, and divided into control group: cells were cultured in conventional media plus recombinant human BMP-2 treatment and experimental group: besides above treaments, calcification inducers ( recombinant human BMP-2, ß-glycerophosphate, L-ascorbic acid, dexamethasone) were added to the culture media. The two group of cells were cultured for 14 days and were stained by Von Kossa, then the cell calcification was observed in this valvular interstitial cells calcification culture model in vitro. Protein expression of intercellular adhesion molecule 1 (ICAM-1), interleukin 8, BMP-2 and BMP-4 was determined by Western blot and BMP-2 secretion was measured by ELISA. RESULTS: In the control group, the structure of human heart valve interstitial cells was clear, and the spindle and radial growth shaped cellular morphology was visible, and Von Kossa staining was negative. In the experimental group, the nuclei become darker in color, and granular sediment distribution was seen surrounding cells, and Von Kossa staining was positive, the cells were forming nodules of calcification. The protein expression of ICAM-1, interleukin 8, BMP-2 and BMP-4 in the experimental was significantly higher than that of the control group (all P < 0.05). The expression of BMP-2 in the experimental group was also significantly higher than that in control group ((92.5 ± 4.9) pg/ml vs. (22.2 ± 1.9) pg/ml, P < 0.05). CONCLUSION: Human BMP-2, ß-glycerophosphate, L-ascorbic acid, and dexamethasone can induce human heart valve interstitial cells calcification and enhance inflammation in vitro by stimulating the secretion of BMP-2.

Changes and significance of IL-25 in chicken collagen II-induced experimental arthritis (CIA).

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease. It is a systemic inflammatory disease, characterized by chronic, symmetrical, multi-articular synovial arthritis. IL-25 (IL-17E) is a member of the recently emerged cytokine family (IL-17s), which is expressed in Th2 cells and bone marrow-derived mast cells. Unlike the other members of this family, IL-25 is capable of inducing Th2-associated cytokines (IL-4, IL-5, and IL-13) and also promotes the release of some pro-immune factors (IL-6 and IL-8). IL-25 is also a pleiotropic factor, which constitutes a tissue-specific pathological injury and chronic inflammation. In this study, we used chicken collagen II-induced experimental arthritis (CIA) model in DBA/1 mice to investigate the relationship between IL-25 and other inflammatory factors, revealing the possible mechanism in CIA. Our results showed that the expression level of IL-25 was enhanced in the late stage of CIA, and IL-17 was increased in the early stage of the disease. It is well known that IL-17 has a crucial role in the development of RA pathogenesis, and IL-25 plays a significant role in humoral immune. For reasons given above, we suggested that the IL-25 inhibited IL-17 expression to some extent, while enhancing the production of IL-4. It was confirmed that IL-25 not only regulated the cellular immune, but also involved the humoral immune in rheumatoid arthritis.

Corynebacterium pyruviciproducens promotes the production of ovalbumin specific antibody via stimulating dendritic cell differentiation and up-regulating Th2 biased immune response.

Corynebacterium pyruviciproducens (C. pyruviciproducens), a newly discovered Corynebacterium, is gram-positive, non-flagellate, non-spore-forming lipophilic rod. No known pathogenic components of Corynebacteria have been found in this new bacterium, such as diphtheria toxin and tuberculostearic acid. In the present study, referring to Propionibacterium acnes (P. acnes), a well-known bacterial adjuvant, the stimulation of dendritic cells by C. pyruviciproducens was analyzed through detecting the levels of cytokine-secretion, ability of cell-proliferation and expression of membrane molecules. In addition, the effect of C. pyruviciproducens in promoting antibody production in vivo was detected. Compared with P. acnes, C. pyruviciproducens more strongly enhanced cytokine secretion including inflammatory factor IL-6 and Th1-associated molecule IL-12, and more effectively induced proliferation, activation or maturation of D2SC/1 (a murine dendritic cell line) and bone marrow-derived dendritic cells (BMDC). Vaccination studies in mice using ovalbumin (OVA) as a model antigen showed that C. pyruviciproducens effectively promoted antigen-specific humoral immune response by increasing OVA-specific antibody, Th2-biased response in spleen and high IL-4/IFN-γ ratio in serum.