Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 6 uppsatser.

Cobalamin must be metabolized intracellularly in order to bind two enzymes: methionine synthase in cytoplasm and methylmalonyl-CoA mutase in mitochondria. Defects in this process cause different inborn errors of cobalamin metabolism (cblA-cblG and mut). A previous study described a cobalamin-binding protein, in addition to methylmalonyl-CoA mutase, in crude mitochondrial fractions. The amount of [57Co]cobalamin bound to this protein was increased in cblB, mut and cblD variant2 cell lines, compared to control cell lines. In the present study, this protein was identified as transcobalamin (TC). Mitochondrial fractions from a cblB cell line were incubated with anti-TC antibodies, which precipitated the cobalamin-bound protein. Analysis of mitochondrial and cytoplasmic fractions isolated from a chloroquine-incubated cblF cell line showed that isolated mitochondrial fractions contain lysosomal material, suggesting that the identified TC is lysosomal. Quantification of cobalamin-bound TC levels in whole cell extracts showed significant increases in cblB and mut groups compared to control cell lines.

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Indiana University-Purdue University Indianapolis (IUPUI) / EFFECTS OF DYNAMATRIX® ON ANGIOGENIC CYTOKINE EXPRESSION FROM HUMAN DENTAL PULP FIBROBLASTS: AN IN VITRO STUDY by Joseph Benjamin Adams Indiana University School of Dentistry Indianapolis, IN Introduction: An exogenous scaffold may lead to more predictable pulp tissue regeneration and continued root formation in a regenerative endodontic procedure. DynaMatrix® is a natural membrane scaffold made of porcine small intestine, currently used in periodontal regenerative surgeries. Objective: The purpose of this study was to investigate if human dental pulp fibroblasts (HDPFs) seeded on DynaMatrix® membrane would result in an increase in the expression of angiogenic cytokines. Materials and Methods: HDPFs (75,000 per well) were seeded in 6-well plates. Three groups were tested: Group 1 (C): HDPFs in 70 media only; Group 2 (M): DynaMatrix® (Cook Biotech, Indianapolis, IN) alone in media; and Group 3 (C+M): HDPFs seeded on DynaMatrix® membranes. After 72 hours of incubation in serum positive, the conditioned media were collected and analyzed for the expression of 20 angiogenic cytokines utilizing RayBiotech Inc., arrays per the manufacturer’s instruction. The data were analyzed by ANOVA. Results: Group M was significantly higher than C for bFGF (p = 0.0023). C+M was significantly higher than M for ANG (p = 0.0104); GRO (p = 0.0003); IFN-γ (p = 0.0023); IL-6 (p = 0.0003); IL-8 (p = 0.0003); Leptin (p = 0.0003); MCP-1 (p = 0.0104); TIMP-1 (p = 0.0190); TIMP-2 (0.0123). C was significantly higher than C+M for ANG (p = 0.0104); MCP-1 (p = 0.0104); and THPO (p = 0.0308). Cytokines such as b-FGF, ANG, and leptin promote angiogenesis, and stimulate migration and proliferation of cells. Conclusion: The cytokine expression profile from the cells seeded on DynaMatrix® suggests that it might be a suitable scaffold for regenerative endodontic procedures. It could improve vascularization by increasing angiogenic cytokines in the microenvironment of the treated root canal and supporting tissue regeneration.