Expression of Enamel Proteins in Human Dental Pulp Stem Cells by the Effect of extracellular Matrix
INTERNATIONAL JOURNAL OF MORPHOLOGY
Authors: Salazar-de Santiago, Alfredo; Avelar-Gonzalez, Francisco J.; Manuel Diaz, Juan; Campos-Navarro, Paloma M.; Flores-Villalpado, Elizz M.; Hernandez-Cuellar, Edgar E.; Guerrero-Barrera, Alma L.
Abstract
Mesenchymal stem cells are present in adult tissues such as the human dental pulp. They are pluripotent and can differentiate into various specialized cell types in vitro through appropriate stimuli. Ameloblasts produce human tooth enamel only during embryonic development before tooth eruption, so endogenous regeneration is not possible. Various efforts have been aimed at generating natural or artificial substitutes for dental enamel with properties similar to the specific components of said tissue. The purpose of this study was to induce human dental pulp stem cells to produce enamel proteins using extracellular matrix derived from the rat tail tendon and pigskin. Primary cultures of human dental pulp stem cells were established and characterized by RT-PCR and immunofluorescence, using mesenchymal cell markers such as CD14, CD40, CD44, CD105, and STRO-1. The cells were then incubated with the extracellular matrix for fourteen days and labeled with specific antibodies to detect the expression of dental enamel proteins such as amelogenin, ameloblastin, enamelisin, tuftelin, and parvalbumin, characteristics of the phenotype of ameloblasts. This work demonstrated a positive effect of the extracellular matrix to induce the expression of enamel proteins in the stem cells of the human dental pulp.
Association between yogurt consumption and plasma soluble CD14 in two prospective cohorts of US adults
EUROPEAN JOURNAL OF NUTRITION
Authors: Luo, Xiao; Sui, Jing; Birmann, Brenda M.; Ivey, Kerry L.; Tabung, Fred K.; Wu, You; Yang, Wanshui; Wu, Kana; Ogino, Shuji; Liu, Hongbo; Giovannucci, Edward L.; Zhang, Xuehong
Abstract
Purpose Although evidence suggests an inverse association between yogurt consumption and the risk of disorders, such as type 2 diabetes and certain cancers, the mechanisms remain poorly understood. We aimed to examine the association between yogurt consumption and concentrations of plasma soluble CD14, a marker of gut barrier dysfunction. Methods We analyzed cross-sectional data from 632 women in the Nurses' Health Study (1989-1990) and 444 men in the Health Professionals Follow-up Study (1993-1994) with soluble CD14 concentrations. We estimated yogurt consumption from food frequency questionnaires. We used multivariable-adjusted linear regression models to estimate the percentage difference (95% CI) of soluble CD14 concentrations by yogurt consumption. Results Among men, higher consumption was associated with a lower soluble CD14 concentration (at least 2 cups/week vs. non-consumers; unadjusted % difference: - 7.6%; 95% CI - 13.0%, - 2.1%;P-trend = 0.003). The inverse association was slightly attenuated following multivariable adjustment (% difference: - 5.8%; 95% CI - 11.0%, - 0.1%;P-trend = 0.01). For the same comparison, yogurt consumption was inverse, but not statistically significant associated with soluble CD14 concentration in women (% difference: - 1.2%; 95% CI - 5.6%, 3.5%;P-trend = 0.64). In stratified analyses, the inverse association between yogurt consumption and the concentrations of soluble CD14 was slightly stronger in men who consumed alcohol at least 20 g/day. Conclusions Higher yogurt consumption was associated with lower soluble CD14 concentrations, especially in men. Our findings suggest the strengthening of gut barrier function as a plausible mechanism for the observed inverse associations of yogurt consumption with gastrointestinal diseases and disorders involving other systems.