Changes in skin structure of the Zip13-KO mouse by Makomo (Zizania latifolia) feeding.

Ehlers-Danlos syndrome (EDS) is a group of disorders caused by abnormalities in the extracellular matrix (ECM). Transforming growth factor-ß (TGF-ß) plays a crucial role in formation of the ECM by the SMAD (Sma-and Mad-related protein, mothers against decapentaplegic homolog) pathway. It has been reported that loss of function of zinc transporter ZRT/IRT-like protein 13 (ZIP13) is the cause of the spondylocheiro dysplastic form of EDS (SCD-EDS: OMIM 612350). Our previous study suggested that TGF-ß1 has a relationship with the skin pathological condition in the Zip13-Knockout (KO) mouse, which is a model of SCD-EDS. Thus far, effective treatment based on modern medicine for this syndrome has not yet been established. According to an approach of traditional Chinese medicine, the present study investigates the medicinal effects of Makomo (Zizania latifolia) on certain aspects of SCD-EDS, such as skin morphology and plasma TGF-ß1, in Zip13-KO mice. Increases in densities of collagen fibers and fibrils without a significant change in thickness of the dermal layer were observed in the group of mice fed a Makomo-containing diet. No change in the amount of collagen suggests that Makomo feed does not elevate collagen synthesis, but changes the length of glycosaminoglycan chains and decreases the distance between collagen fibrils. In conclusion, the changes of the skin structure suggest that Makomo can increase the mechanical strength of skin.

Amino acid derivative-mediated detoxification and functionalization of dual cure dental restorative material for dental pulp cell mineralization.

Current dental restorative materials are only used to fill the defect of hard tissues, such as dentin and enamel, because of their cytotoxicity. Therefore, exposed dental pulp tissues in deep cavities must be first covered by a pulp capping material like calcium hydroxide to form a layer of mineralized tissue. However, this tissue mineralization is based on pathological reaction and triggers long-lasting inflammation, often causing clinical problems. This study tested the ability of N-acetyl cysteine (NAC), amino acid derivative, to reduce cytotoxicity and induce mineralized tissue conductivity in resin-modified glass ionomer (RMGI), a widely used dental restorative material having dual cure mechanism. Rat dental pulp cells were cultured on untreated or NAC-supplemented RMGI. NAC supplementation substantially increased the percentage of viable cells from 46.7 to 73.3% after 24-h incubation. Cell attachment, spreading, proliferative activity, and odontoblast-related gene and protein expressions increased significantly on NAC-supplemented RMGI. The mineralization capability of cells, which was nearly suppressed on untreated RMGI, was induced on NAC-supplemented RMGI. These improved behaviors and functions of dental pulp cells on NAC-supplemented RMGI were associated with a considerable reduction in the production of intracellular reactive oxygen species and with the increased level of intracellular glutathione reserves. These results demonstrated that NAC could detoxify and functionalize RMGIs via two different mechanisms involving in situ material detoxification and antioxidant cell protection. We believe that this study provides a new approach for developing dental restorative materials that enables mineralized tissue regeneration.

Effect of ultraviolet photoactivation of titanium on osseointegration in a rat model.

PURPOSE: The objective of this study was to determine whether ultraviolet (UV) light treatment of titanium implants could enhance osseointegration to sufficiently overcome the negative aspects of shorter implants in a rat femur model. MATERIALS AND METHODS: Acid-etched miniature titanium implants with lengths of 2 mm (longer implants) and 1.2 mm (shorter implants) were prepared. Some of these implants were treated with UV light for 48 hours prior to surgery. The strength of osseointegration generated by these implants was evaluated using a biomechanical implant push-in test in a rat model. Peri-implant osteogenesis was examined by scanning electron microscopy for tissue morphology and energy dispersive x-ray spectroscopy for elemental composition. RESULTS: Push-in test values for the longer implants were 80% and 100% greater than those of the shorter implants at weeks 4 and 8 of healing, respectively. UV treatment of the shorter implants significantly increased their push-in value, resulting in a 100% higher value than untreated longer implants at week 2 and a push-in value that was equivalent to that of the untreated longer implants at weeks 4 and 8. Scanning electron micrographs and energy dispersive x-ray spectroscopic examinations after push-in testing revealed that the UV-treated implant surfaces were covered more extensively by bone or tissue remnants containing calcium and phosphorous than the untreated surfaces. The titanium surfaces were converted from hydrophobic to superhydrophilic status after UV treatment, although the cause-result relationship between the acquired superhydrophilicity and biologic effects remained unclear. CONCLUSIONS: Within the limits of this investigation, UV light pretreatment substantially enhanced the osseointegration capacity of acid-etched titanium implants. The deficiencies of osseointegration in implants with a 40% shorter length were overcome by UV treatment in the rat model using miniature implants. These results need to be confirmed in other animal models and implants that more closely resemble human dental implants to determine the true clinical significance.

Spontaneous differentiation of mesenchymal stem cells obtained from fetal rat circulation.

Mesenchymal stem cells (MSCs) are thought to be multipotential, capable of differentiating into multiple lineages. We attempted to characterize rat cells derived from fetal circulating blood (FCBCs) that displayed a fibroblastic morphology and differentiated into osteoblastic and chondrocytic lineages. Notably, they differentiated into a chondrocyte-specific phenotype on plastic culture dishes in medium supplemented only with 10% fetal bovine serum (FBS) without the use of a three-dimensional culture substrate. Bone marrow-derived cells did not convey such phenotypic expression under the same conditions. The characteristic features of these cells were analyzed by reverse transcription polymerase chain reaction, immunohistological and von Kossa staining, and by immuno-dot blotting. In one population, expression of collagen types II and X was detected in differentiated cells at the same levels as observed in chondrocytes derived from rat rib cartilage. In another population, parathyroid hormone receptor, alkaline phosphatase, and osteocalcin were also expressed at levels almost equal to those observed in long bone-derived osteoblasts. After 3 weeks in culture, extensively condensed cell masses, stained with anti-type II collagen antibody, could be distinguished histologically from small, multilayered, von Kossa-positive nodules, which stained with anti-osteocalcin, but not with anti-type II collagen antibody. In addition, the FCBCs differentiated into adipogenic cells in the presence of methyl-isobutyl xanthine, dexamethasone, insulin, and indomethacin. These cells expressed PPARgamma2 mRNA and accumulated lipid vesicles detectable by Oil red-O staining. Our findings suggest that FCBCs have the potential to readily differentiate into multiple lineages and that they are distinct from mesenchymal stem cells derived from bone marrow or circulating blood from more mature and adults in their spontaneous differentiation in the absence of specific factors such as transforming growth factor-beta (TGF-beta) or dexamethasone, or a three-dimensional culture environment.