Light Energy Accumulation from Pyrene Derivative to Tris(bipyridine)ruthenium on Clay Surface.

A novel type of energy donor-acceptor system on a clay surface has been prepared. The energy transfer between an energy-donating cationic pyrene derivative (An-Py2+) and an energy-accepting tris(bipyridine)ruthenium complex (Ru2+) on the clay surface was investigated using absorption, emission, and lifetime measurements. An obvious energy transfer was observed, and one Ru2+ molecule quenched the emission from five molecules of An-Py2+ with an emission quenching efficiency of 85% on the clay surface. This suggests that the light energies absorbed by five of the An-Py2+ molecules were accumulated in the one Ru2+ molecule. Near-quantitative emission quenching was observed for stoichiometric amounts of An-Py2+ and Ru2+. The apparent quenching rate constant is approximately 1017 L mol-1 s-1, and thus the quenching rate constant is 107-108 times higher than the diffusion rate constant in a homogeneous solution.

Inorganic polyphosphate differentiates human mesenchymal stem cells into osteoblastic cells.

The existence of inorganic polyphosphates [poly(P)] in human cells has been demonstrated. In osteoblasts, it is suggested that the concentration of cellular poly(P) is relatively high. In this study, we examined whether poly(P) accelerates the differentiation of human mesenchymal stem cells (hMSCs) from patients with osteoarthritis (OA) and rheumatoid arthritis (RA) into osteoblastic cells. Alkaline phosphatase (ALP) activity was induced by poly(P) in hMSCs from both OA and RA. In Alizarin Red S and osteocalcin EIA, there was a significant difference between the control and poly(P) group. In real-time PCR, there was a significant difference in ALP, collagen type 1A, osteocalcin, and bone sialoprotein between the control and poly(P) group. Our findings suggest that poly(P) have the potent role of differentiating hMSCs into osteoblastic cells at the early and later stages of osteoblastic differentiation.

[Application of NFkappaB inhibitor for arthritis].

Recent progress in DNA technologies has provided the strategies to regulate the transcription of disease-related genes in vivo using antisense oligodeoxynucleotide (ODN). Transfection of cis-element double-stranded oligodeoxynucleotides (decoy ODNs) has been reported as a new therapeutic tool of anti-gene strategies for gene therapy. In the field of arthritis, decoy ODNs strategies have been significant therapeutic potential. The concept of regulation the disease related gene expression at the level of transcriptional factor may be more therapeutic effects compared with monotherapy in arthritis. Injection of NFkappaB decoy ODN into the affected joint resulted in marked suppression of joint destruction in CIA models. In vitro studies demonstrated that the inhibitory effect on inflammatory cytokines and matrix metalloproteinase production from stimulated synovial cells derived from rheumatoid arthritis patients. NFkappaB decoy ODN inhibited induction of osteoclasts and bone resorption ability. Parthenolide is one of the main sesquiterpense lactones responsible for the bioactivities of feverfew and recently reported to inhibit NFkappaB activation. Parthenolide has ameliorated the severity of joint destruction in experimental animal model. Based upon these findings, NFkappaB may be one of important therapeutic target for arthritis.

Equivalent osteoblastic differentiation function of human mesenchymal stem cells from rheumatoid arthritis in comparison with osteoarthritis.

OBJECTIVE: To evaluate the osteoblastic differentiation of human mesenchymal stem cells (hMSCs) in patients with RA. METHODS: Heparinized bone marrow aspirate was obtained from patients with OA and RA. Mononuclear cells were cultured for 2 weeks and a colony-forming assay was performed. The phenotype of cells was analysed by flow cytometry. Passage 2 cells were cultured with beta-glycerophosphate (bGP) in the control group and bGP, ascorbic acid and dexamethasone in the differentiation group. After 2 weeks, ALP staining and activity were performed. After 3 weeks, Alizarin Red S assay was performed. Total RNA was extracted from cells cultured for 2 and 3 weeks. Gene expression of bone formation factor was examined by real-time PCR. RESULTS: The phenotype of cells was identical in both OA and RA and the content was thought to be hMSCs. The results of ALP activity and Alizarin Red S assay showed higher levels in the differentiation group for both OA and RA samples compared with the control group. The results of a colony-forming assay were identical in both OA and RA samples. Gene expression in the differentiation group was higher than in the control group in both OA and RA samples. There was no significant difference between OA and RA samples in all experiments. CONCLUSION: The function of osteoblastic differentiation of hMSCs is similar between OA and RA.