Mitogenic activity of gelatin to murine spleen cells

Osteogenic stimulation of human dental pulp stem cells with a novel gelatin-hydroxyapatite-tricalcium phosphate scaffold

The aim of the present study was to construct and compare gelatin-HA-TCP scaffolds with a gelatin-only scaffold and to investigate the effect of the scaffold on osteogenic differentiation of human dental pulp stem cells. We developed a novel scaffold for bone tissue engineering via a solution casting/particle washing method, and the physical and mechanical properties of the scaffolds were examined using scanning electron microscopy and a universal testing machine, respectively. Scaffold cytotoxicity toward human dental pulp stem cells (hDPSCs) was evaluated with the CCK8 method, and hDPSC differentiation was evaluated with an alkaline phosphatase activity assay, alizarin red S staining, and reverse transcription-polymerase chain reaction (RT-PCR). Our results indicate that the gelatin-HA-TCP scaffolds exhibited good homogeneity, interconnected pores, and relatively high mechanical strength and water absorption rates. A significant increase in hDPSC proliferation and ALP activity that stimulated mineralization of the hDPSC-generated matrix was also seen on gelatin-HA-TCP scaffolds compared with the gelatin-only scaffolds. In addition, RT-PCR revealed that the gelatin-HA-TCP scaffold upregulated gene expression of the osteogenic markers Runx2, bone sialoprotein, and OSX. In conclusion, gelatin-HA-TCP scaffolds presented better mechanical properties, cytocompatibility and differentiation-inducing characteristics than gelatin scaffolds. These results indicate that the novel hydrogel gelatin-HA-TCP scaffolds may be a promising biomaterial for bone tissue engineering. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1851-1861, 2018.

Activity of gelatins to induce secretion of a variety of cytokines from murine peritoneal exudate macrophages

Previously, we observed that liquid form bovine bone (BB) gelatin stimulates murine spleen cells to proliferate in vitro. In this study, activity of BB gelatin to stimulate murine-adherent peritoneal exudate cells (PEC) to secrete cytokines has been examined. Quantitatively, BB gelatin stimulated adherent PEC of C3H/HeN mice to secrete interleukin (IL)-12 (+p40), TNF-alpha, and IL-6 but not IL-1beta, IL-2, IL-10, and IFN-gamma. Qualitatively, BB gelatin-induced secretion of KC, MIP-2, MCP-1, RANTES, and MIP-1a as well as IL-6 but not 6Ckine, CTACK, Eotaxin, G-CSF, GM-CSF, IL-2,-3,-4,-5,-9,-10,-12,-13,-17, Leptin, IFN-gamma, SCF, sTNFri, TARC, TNF-alpha, TIMP-1, Tpo, and VEGF. BB gelatin acted on adherent PEC of C3H/HeN mice but not C3H/HeJ mice, which lack Toll-like receptor 4. Polymyxin B, a LPS antagonist, did not inhibit the activity of BB gelatin. Lipopolysaccharide (LPS) but not BB gelatin induced secretion of an appreciable amount of mIL-1beta. These results suggest that the activity of BB gelatin is not attributed to contamination of LPS but BB gelatin itself. It was also suggested that BB gelatin stimulated adherent PEC to newly produce and secrete cytokines.

Comparison between bovine bone and porcine skin gelatins in their effects on murine cell proliferation

We investigated relationship between porcine skin (PS) and bovine bone (BB) gelatins in their actions on proliferation of murine benign and malignant cells in this study. We previously observed that BB gelatin enhanced spleen cell proliferation. The present study showed that such an activity of BB gelatin was not exerted in a serum-free medium. On the other hand, PS gelatin suppressed proliferation of normal spleen cells and of those stimulated by concanavalin A (Con A). It is not known whether or not such an activity of PS gelatin on Con A-stimulated spleen cells is exerted in the serum-free medium since Con A was unable to augment proliferation of spleen cells in that medium. BB gelatin as well as PS gelatin suppressed proliferation of RL male symbol 1 cells, a T cell lymphoma cell line of Balb/c mice, and such an activity of BB gelatin was not exerted in the serum-free medium whereas PS gelatin exerted its activity in the same medium. Mitomycin C (MMC)-treated spleen cells as well as MMC-treated RL male symbol 1 cells partly released RL male symbol 1 cells from the inhibition of proliferation by PS gelatin. MMC-treated RL male symbol 1 cells as well as MMC-treated spleen cells suppressed the proliferation of spleen cells augmented by BB gelatin. Inhibition of RL male symbol 1 cell proliferation by PS gelatin was not affected by BB gelatin, but enhancement of spleen cell proliferation by BB gelatin was attenuated by PS gelatin regardless of the sequence of treating the spleen cells with PS gelatin. Enhancement of spleen cell proliferation by BB gelatin was time-dependent but suppression of RL male symbol 1 cell proliferation by PS gelatin was not. In conclusion, BB gelatin enhanced proliferation of spleen cells and suppressed proliferation of RL male symbol 1 cells. In both cases, fetal calf serum (FCS) was required. PS gelatin suppressed proliferation of spleen cells and of RL male symbol 1 cells without FCS.

In vitro effect of gelatins on murine cell proliferation

Porcine skin (PS) gelatin suppressed proliferation of a murine hepatic cell carcinoma cell line, MH134, a murine fibrosarcoma cell line, Meth A and a murine T cell lymphoma cell line, RL Male 1. The magnitude of suppression of the proliferation by cold water fish skin (CWFS) or bovine bone (BB) gelatin was lower than that by PS gelatin. On the other hand, BB gelatin stimulated proliferation of murine spleen cells. The magnitude of stimulation of the proliferation by CWFS gelatin was lower than that by BB gelatin. PS gelatin slightly suppressed proliferation of murine spleen cells. PS gelatin induced apoptosis but not necrosis of MH134 tumor cells. CWFS gelatin induced weaker apoptosis of the cells than PS gelatin. DNA histogram indicated that PS and CWFS gelatins acted on MH134 tumor cells to increase ratios of G2 + M-phase.