Mutual promotions between periodontitis and vascular calcification by rat animal model.

OBJECTIVE AND BACKGROUND: To study the relationship between periodontitis and vascular calcification by establishing rat model of chronic periodontitis and vascular calcification. METHODS: Forty male Wistar rats were divided into four groups randomly: control group, periodontitis group, vascular calcification group, and compound periodontitis and calcification group. Each group rats accepted the corresponding manages to establish the animal model. Clinical examinations and hematoxylin and eosin staining of periodontal tissue were taken to test the periodontal model; calcium assay, alkaline phosphatase activity, expression of mineral-related factors including osteopontin, alkaline phosphatase, core-binding factor-α1 and bone sialoprotein, hematoxylin and eosin staining and von Kossa staining of vascular tissue were taken to test the vascular calcification model; inflammatory factors including C-reactive protein, interleukin-1ß, tumor necrosis factor-α, interleukin-6, prostaglandin E2, and serum lipid in serum were also detected at the same time. RESULTS: The rat model was established. Inflammation of periodontal tissue and alveolar bone resorption in compound group and periodontitis group were more obvious than those in control group and vascular calcification group (P < .05). However, the calcium assay, alkaline phosphatase activity, and mineralized deposition in vascular calcification group and compound group were higher than those in control group and periodontitis group (P < .05), and compound group were the highest (P < .05); as for serum lipid, the level of total cholesterol and low-density lipoprotein-cholesterol in compound group and vascular calcification group were higher than that in control group and periodontitis group (P < .05), and compound group was the highest (P <.05); but the level of high-density lipoprotein cholesterol was higher in control group and periodontitis group. Inflammatory factors expression in serum were higher in compound group and periodontitis group, while mineral-related factors expression were higher in compoundgroup and vascular calcification group. CONCLUSION: There are some mutual promotions between periodontitis and vascular calcification, which might be related to the increasing inflammatory factors, lipids level, and mineral-related factors.

Osteoprotegerin/receptor activator of nuclear factor-κB ligand are involved in periodontitis-promoted vascular calcification.

The present study explored the potential role of osteoprotegerin (OPG)/receptor activator of nuclear factor-κB (RANK)/receptor activator of nuclear factor-κB ligand (RANKL) in promoting vascular calcification by periodontitis. Thirty-six male Wistar rats were randomly assigned to four groups to establish animal models as follows: the sham group (group C), vascular calcification group (group VDN), periodontitis group (group CP), and test group (group CP+VDN). After eight weeks, all the rats were sacrificed. The periodontal and vascular calcification indices were detected. Quantitative polymerase chain reaction (qPCR), immunohistochemistry, western blot analysis, and enzyme-linked immunosorbent assay (ELISA) were used to quantify OPG/RANK/RANKL expression in vascular tissue and serum. Protein expression analyses revealed the expression of OPG and RANKL in the vascular tissues of the four groups. The expression of OPG in group C was the highest, which was similar to group CP+VDN, and the expression of OPG in groups CP and VDN were lower. However, the expression of RANKL was inversely correlated with OPG, and the ratio of RANKL/OPG was also higher in groups CP and VDN than that in groups C and CP+VDN. In conclusion, OPG/RANK/RANKL may play an essential role in the promotion of vascular calcification by periodontitis. However, the expression levels of OPG and RANKL were not simply superimposed when periodontitis and vascular calcification co-existed.

Self-assembling zeolite crystals into uniformly oriented layers.

We report important progress made in the synthesis of oriented functional layers of nanochannel materials by using coordination chemistry as a tool. Zeolite L (ZL) crystals have been arranged into oriented layers through the coordinative interactions between a functional organic linker (L) and metal cations used for connecting the different parts. As organic linker we used a terpyridyl ligand bearing a urea group and a reactive siloxane part. Two strategies that lead to monolayers with different properties are described. The first consists of reacting the siloxane group of ligand L with OH groups of the substrate (S), and selectively reacting the siloxane group of L with OH groups located at the base of the ZL crystals. Next, metal cations M(n+), for example, Zn(2+) or Cu(2+), are coordinated to the terpy group on the modified substrate. To this the modified ZL is added and coordinatively bound by the terpy(Mn(n+))terpy interaction, leading to oriented ZL layers. The second method consists of reacting substrate S and ligand L in the presence of a metal cation. A layer with reactive siloxane groups is formed on S to which the ZL crystals are bound by the reaction of the hydroxyl groups of their base. Zn(2+), Cu(2+), and lanthanide ions Eu(3+) and Tb(3+)have been tested successfully, all of them leading to high-quality ZL monolayers with open channels, accessible for accepting guests, oriented perpendicularly with respect to the surface of S.

Porphyromonas gingivalis Lipopolysaccharide Stimulation of Vascular Smooth Muscle Cells Activates Proliferation and Calcification.

BACKGROUND: Porphyromonas gingivalis (Pg) is a major etiologic agent of periodontitis, whose virulence has been attributed to different factors, including lipopolysaccharide (LPS). Vascular ectopic calcification as a well-known major risk factor for adverse cardiovascular diseases is a highly prevalent vascular pathophenotype, and vascular smooth muscle cells (VSMCs) play an important role in mediating vascular calcification. It was hypothesized that Pg-LPS may stimulate vascular calcification through a direct effect on VSMC function. To test this hypothesis, the effect of Pg-LPS on VSMC calcification was determined. METHODS: Primary cultures of VSMCs were obtained and identified by immunochemistry in vitro. The proliferation and alkaline phosphatase (ALP) activity of VSMCs were measured using a cell counting kit and an ALP activity test. Mineral deposition was examined using alizarin red staining. Gene (e.g. ALP, core binding factor α1 [Cbfα1], bone sialoprotein [BSP], and osteopontin [OPN]) expression levels altered by Pg-LPS were determined by reverse transcription-polymerase chain reaction array. RESULTS: Pg-LPS could increase the proliferation of VSMCs at different times and enhance ALP activity of VSMCs after 1 day. Alizarin red staining and quantification showed that, with Pg-LPS treatment, VSMCs displayed more obvious calcification nodules. When stimulated with Pg-LPS, the expression of specific osteogenic genes (e.g., ALP, Cbfα1, BSP, and OPN) was significantly promoted in the presence or absence of mineralization-inducing medium, whereas the expression of the OPN gene was inhibited in the mineralization induction group at day 7. CONCLUSION: Pg-LPS can stimulate VSMC calcification, which results in vascular calcification, further proving the precise relationship between periodontitis and vascular calcification.

[Expression of OPG/RANK/RANKL in the rat dental pulp tissue of periodontitis combined with vascular calcification and its clinical significance].

PURPOSE: To study the expression and possible role of OPG/RANK/RANKLin the rat dental pulp of periodontitis combined with vascular calcification. METHODS: Thirty-six male Wister rats were randomly divided into 4 groups: control group(group C), periodontitis group(group CP), vascular calcification group(group VDN) and compound group(group CP+VDN). Each group underwent corresponding management to establish animal model. When the model was successful, the maxillae including molars were sectioned, pulp tissue was examined by H-E staining; Immunohistochemical staining method was used to evaluate the expression and ratio of OPG and RANKL in pulp tissues. Statistical analysis was carried out using SPSS 19.0 software package. RESULTS: The pulp tissue of group CP, VDN, CP+VDN showed varied degrees of damage, neutrophil infiltration, pulp vascular congestion, odontoblasts vacuolar changes, pulp necrosis by H-E staining, and the changes in CP+VDN group was the most significant, followed by CP group, VDN group. Immunohistochemistry showed OPG in pulp tissues in group CP, VDN, CP+VDN were significantly lower than that in normal group (P<0.05), and the expression in group CP+VDN was the least;Expression of RANKL in pulp tissues in group CP, VDN, CP+VDN were significantly higher than that in normal group(P<0.05)，and the expression in group CP+VDN was the highest. The ratio of OPG/RANKL in normal group was the highest, and the ratio in CP+VDN group was the lowest. CONCLUSIONS: Periodontitis and vascular calcification can damage the pulp tissue, periodontitis compound with vascular calcification may aggravate the injury; OPG/RANKL/RANK system may play an important role in pulp tissue injury.

A novel ionic liquid-metal complex electrolyte for a remarkable increase in the efficiency of dye-sensitized solar cells.

A novel ionic liquid-metal complex (ILMC) electrolyte was developed for dye-sensitized solar cells (DSCs). A high efficiency of nearly 7% was achieved, which was 69.2% higher compared with an ionic liquid (IL) electrolyte without a metal center. The high conductivity, inhibited electron recombination and longer electron lifetime contribute to the superior performance of the ILMC electrolyte.