An association analysis for genetic factors for dental caries susceptibility in a cohort of Chinese children.

OBJECTIVE: To comprehensively investigate the effects of 25 variants in 15 genes on dental caries susceptibility in a cohort of Chinese children. METHODS: A total of 25 variants in 15 genes were genotyped with MassARRAY iPLEX system and analyzed in 265 healthy controls and 254 children affected by dental caries with different dmft scores. The children with dental caries were stratified into "mild group" (scores from 1 to 3), "moderate group" (scores from 4 to 6), and "severe group" (scores from 7 to 14). RESULTS: The association analysis revealed that rs11362 of defensin ß1 (DEFB1) was significantly associated with dental caries susceptibility (OR = 2.447, p = 1.165E-04). Furthermore, rs11362 was positively correlated with the severity of dental caries. For another selected variant of DEFB1, rs1799946 was significantly associated with dental caries susceptibility in the severe group (OR = 0.473, p = 3.70E-03) and also significant in the group consisted of moderate and severe subjects (OR = 0.623, p = .033). The results from logistic regression in additive, dominant, and recessive models also exhibited the similar patterns. CONCLUSION: Out of 25 selected variants, only 2 of DEFB1 gene (rs11362 and rs1799946) were significantly associated with dental caries susceptibility in children.

Effects of dynamic radial tensile stress on fibrocartilage differentiation of bone marrow mesenchymal stem cells.

BACKGROUND: Uniaxial/biaxial tensile stress has been employed to induce chondrocyte differentiation of mesenchymal stem cells. However, the effects of radial tensile stimuli on differentiation of MSCs into fibrocartilage remain unclear. RESULTS: It was found that induced bone marrow mesenchymal stem cells (BMSCs) were not only similar to TMJ disc cells in morphology, but also could synthesize type I collagen (Col I), a small amount of type II collagen (Col II) and glycosaminoglycans (GAGs). The synthesis of Col I significantly increased while that of Col II gradually decreased with increasing tensile strength. The ratio of Col I to Col II was 1.8 to 1 and 2 to 1 in the 10% and 15% stretching groups, respectively. The gene expression of Col I and GAGs was significantly upregulated, whereas that of Col II was downregulated. However, the higher tensile stimulation (15%) promoted the synthesis of α-smooth muscle actin (α-SMA). Too much α-SMA is not conducive to constructing engineered tissue. CONCLUSION: Therefore, the 10% radial tensile stimulus was the optimal strength for inducing the BMSCs to differentiate into fibrochondrocytes of the temporomandibular joint (TMJ) disc. This work provided a novel approach for inducing BMSCs to differentiate into fibrochondrocytes.

40-Fold Enhanced Intrinsic Proton Conductivity in Coordination Polymers with the Same Proton-Conducting Pathway by Tuning Metal Cation Nodes.

Three isostructural imidazole-cation-templated metal phosphates (FJU-25) are the first examples to demonstrate that the tuning of metal cation nodes can be an efficient strategy to significantly improve the proton conductivity without changing the structure of the proton-conducting pathway.

[Effects of basic fibroblast growth factor on bone marrow mesenchymal stem cell differentiation into temporomandibular joint disc cells].

The present paper is aimed to observe the effects of basic fibroblast growth factor (bFGF) on bone marrow mesenchymal stem cell (BMSCs) differentiation. The bFGF was used to stimulate BMSCs and histology, immunohistochemistry and enzyme linked immunosorbent assay (ELISA) were used to examine the extracellular matrix produced by induced BMSCs, evaluated the feasibility of BMSCs being the seeding cells of temporomandibular joint (TMJ) disc tissue engineering. The results showed that having been induced with bFGF, the BMSCs could differentiate into fibroblast-like cells, which could synthesize GAG and collagen type I matrix. So it is feasible for BMSCs as seeding cells for engineered TMJ disc.

[Cell sources for engineered temporomandibular joint disc tissue: present and future].

The purpose of this review is to provide a reference for researchers in investigating the tissue engineering of the temporomandibular joint (TMJ) disc. Currently tissue engineering of the TMJ disc is in its infancy, and cell source is one of the key factors that define the development of the tissue engineering of TMJ disc. In this paper, 6 kinds of cells: the TMJ disc native cells, chondrocytes, dermal fibroblasts, bone marrow-derived mesenchymal stem cells, adipose-derived stem cells, and embryonic stem cells are introduced. In addition, the possibility that these cells can be used as cell sources for TMJ disc tissue engineering is described.

Nanomorphological and mechanical reconstruction of mesenchymal stem cells during early apoptosis detected by atomic force microscopy.

Stem cell apoptosis exists widely in embryonic development, tissue regeneration, repair, aging and pathophysiology of disease. The molecular mechanism of stem cell apoptosis has been extensively investigated. However, alterations in biomechanics and nanomorphology have rarely been studied. Therefore, an apoptosis model was established for bone marrow mesenchymal stem cells (BMSCs) and the reconstruction of the mechanical properties and nanomorphology of the cells were investigated in detail. Atomic force microscopy (AFM), scanning electron microscopy (SEM), laser scanning confocal microscopy (LSCM), flow cytometry and Cell Counting Kit-8 analysis were applied to assess the cellular elasticity modulus, geometry, nanomorphology, cell surface ultrastructure, biological viability and early apoptotic signals (phosphatidylserine, PS). The results indicated that the cellular elastic modulus and volume significantly decreased, whereas the cell surface roughness obviously increased during the first 3 h of cytochalasin B (CB) treatment. Moreover, these alterations preceded the exposure of biological apoptotic signal PS. These findings suggested that cellular mechanical damage is connected with the apoptosis of BMSCs, and the alterations in mechanics and nanomorphology may be a sensitive index to detect alterations in cell viability during apoptosis. The results contribute to further understanding of apoptosis from the perspective of cell mechanics.

Feasibility of peaking carbon emissions of the power sector in China's eight regions: decomposition, decoupling, and prediction analysis.

Carbon emissions in the power sector are an important part of China's total carbon emissions and have a significant impact on whether China can achieve the 2030 carbon peak target. Based on the three perspectives of decomposition, decoupling, and prediction, this paper studies the feasibility of carbon emission peaks in eight major regional power sectors in China. First, the generalized Divisia index model (GDIM) is used to decompose the carbon emissions of the eight regional power sectors, and the driving factors and their effects on carbon emissions in the power sector of each region are compared. Then, the decoupling index based on the generalized Divisia index model (GDIM-D) is used to study the decoupling relationship between the carbon emissions of the eight regional power sectors and economic growth. Finally, the carbon emissions and decoupling indices of the power sector from 2017 to 2030 are predicted. The results show the following. First, the gross domestic product (GDP) and output scale are the main factors contributing to the carbon emissions of the eight regional power sectors. The carbon intensity of the power sector in GDP (C/G) and output carbon intensity(C/E) are the main factors that contribute to the reduction. Second, the carbon emissions of the southern coast, the middle Yellow River, and the Southwest peaked in 2013 and have been decoupled from economic growth, while those in the other regions have not peaked or decoupled. Third, if the carbon emissions of the power sector in the Northeast, northern coast, eastern coast, middle Yangtze River, and Northwest reach a peak in 2030, they will face many emission reduction pressures. This paper provides a reference for studying the carbon emissions of China's regional power sectors and their relationship with economic growth and has important implications for peak carbon emissions at the national level.

Mechanical, nanomorphological and biological reconstruction of early­stage apoptosis in HeLa cells induced by cytochalasin B.

There is a growing interest in the fact that mechanical signals may be as important as biological signals in evaluating cell viability. To investigate the alterations in biomechanics, nanomorphology and biological apoptotic signals during early apoptosis, an apoptosis model was established for cervical cancer HeLa cells induced by cytochalasin B (CB). The cellular mechanical properties, geometry, morphology and expression of key apoptotic proteins were systematically analyzed. The findings indicated a marked decline in cellular elastic modulus and volume and a considerable increase in surface roughness occurring prior to the activation of biological apoptosis signals (such as phosphatidylserine exposure or activation of CD95/Fas). Moreover, the depolymerization of filamentous actin aggravated the intracellular crowding degree, which induced the redistribution of different­sized protein molecules and protrusions across the cell membrane arising from excluded volume interactions. Statistical analysis revealed that the disassembly of the actin cytoskeleton was negatively correlated with the cellular elastic modulus and volume, but was positively correlated with surface roughness and CD95/Fas activation. The results of the present study suggest that compared with biological signals, mechanical and geometrical reconstruction is more sensitive during apoptosis and the increase in cell surface roughness arises from the redistribution of biophysical molecules. These results contribute to our in­depth understanding of the apoptosis mechanisms of cancer cells mediated by cytochalasin B.

[Topography and mechanical property of goat temporomandibular joint disc cells].

OBJECTIVE: This study is performed to investigate the cell topographies and biomechanical properties of two different types of temporomandibular joint (TMJ) discs from goats by using JPK Nano Wizard 3 biological atomic force microscopy (AFM). This process provides a guideline for selecting seed cells for TMJ disc tissue engineering. METHODS: TMJ disc cells from primary goats were cultured by monolayer culture method. AFM was used to contact scan the topographies of the two types of TMJ disc cells under physiological environment. Approximately 20 chondrocyte-like and fibroblast-like cells were selected randomly to plot the force-versus-distance curves of the cytoplasm and nucleus. Young's modulus and adhesion were analyzed by JPK Data Processing. RESULTS: The triangle-shapednucleus of the chondrocyte-like cell occupied a large portion of the cell. Cytoskeleton was arranged dendritically on the surface. Pseudopodia were extended from cell edges. The spindle-shaped nucleus of the fibroblast-like cell occupied a significantly larger region compared with the cytoplasmic region. Cytoskeleton was arranged regularly. Cell edges were smooth with less pseudopodia extended. No difference was found in the surface roughness between the two types of cells. According to the force-versus-distance curves, the Young's moduli of the two types of cells were not statistically different (P>0.05), but differences were found in the cytoplasmic regions (P=0.047). No statistical difference was found in the adhesions between the two types of cells (P>0.05). CONCLUSION: The AFM topography and curves were compared and analyzed. The two types of TMJ disc cells exhibited significantly different topographies, but only slight difference in their mechanical abilities.

Peroxisome proliferator-activated receptor alpha expression changes in human pregnant myometrium.

Peroxisome proliferator-activated receptor alpha (PPARα) has been demonstrated to exhibit anti-inflammatory activities that are hypothesized to play a key role in labor suppression and maintenance of uterine quiescence. The aim of this study was to identify pregnancy- and labor-associated changes in PPARα in human myometrium. For this investigation, human myometrium was obtained from premenopausal women, and the study participants were categorized into the following 4 groups: nonpregnant (NP; n = 10), preterm not in labor (PNL; n = 10, gestation range 20-35 weeks), term not in labor (TNL; n = 20, gestation range 37-41 weeks), and term in labor (TL; n = 20, gestation range 37-41 weeks). Immunohistochemistry was used to locate and confirm the expression of PPARα. Relative quantitative real-time polymerase chain reaction (PCR) and Western blotting were employed to study the expression of anti-inflammatory PPARα and proinflammatory interleukin 1ß (IL-1ß). Immunohistochemistry indicated that PPARα was located in the nucleus of uterine smooth muscle cells. Compared to other groups, in PNL group, the PPARα messenger RNA (mRNA) and protein increased significantly. Decreased PPARα mRNA and protein expressions in myometrium were associated with labor while IL-1ß increased remarkably. There were negative correlations between PPARα and IL-1ß on mRNA (r = -.765, P < .01) and protein (r = -.624, P < .01) levels analyzed using Pearson test. In conclusion, human pregnancy is associated with changes in expression of PPARα and IL-1ß in myometrium. The changes observed suggest that PPARα may play a role in maintaining pregnancy or initiating labor through inhibiting the expression of IL-1ß in human myometrium.