Objective. To elucidate the role of microRNA (miRNA) in the pathogenesis of rheumatoid arthritis (RA), we analyzed synoviocytes from RA patients for their miRNA expression.Methods. Synoviocytes derived from surgical specimens obtained from RA patients were compared with those obtained from osteoarthritis (OA) patients for their expression of a panel of 156 miRNA with quantitative stem-loop reverse transcription-polymerase chain reaction. The miRNA whose expression decreased or increased in RA synoviocytes as compared with OA synoviocytes were identified, and their target genes were predicted by computer analysis. We used an in vitro system of enhancing the expression of specific miRNA by transfection of precursors into synoviocytes, and then we performed proliferation, cell cycle, and apoptosis assays, as well as enzyme-linked immunosorbent assays for cytokine production. The effects of transfection on predicted target protein and messenger RNA (mRNA) were then examined by Western blot analysis and luciferase reporter assay.Results. We found that miR-124a levels significantly decreased in RA synoviocytes as compared with OA synoviocytes. Transfection of precursor miR-124a into RA synoviocytes significantly suppressed their proliferation and arrested the cell cycle at the G 1 phase. We identified a putative consensus site for miR-124a binding in the 3 -untranslated region of cyclin-dependent kinase 2 (CDK-2) and monocyte chemoattractant protein 1 (MCP-1) mRNA. Induction of miR-124a in RA synoviocytes significantly suppressed the production of the CDK-2 and MCP-1 proteins. Luciferase reporter assay demonstrated that miR-124a specifically suppressed the reporter activity driven by the 3 -untranslated regions of CDK-2 and MCP-1 mRNA.Conclusion. The results of this study suggest that miR-124a is a key miRNA in the posttranscriptional regulatory mechanisms of RA synoviocytes.MicroRNA (miRNA) are a well-established class of small (ϳ22 nucleotides) endogenous noncoding RNAs that influence the stability and translation of messenger RNA (mRNA) (1). Using various computational and experimental approaches, hundreds of miRNA have been identified in numerous animal species. The miRNA genes are transcribed by RNA polymerase II as primary miRNA (pri-miRNA) (2,3). The RNase III enzyme Drosha then processes the nuclear pri-miRNA, yielding a ϳ70-nucleotide molecule known as precursor miRNA (pre-miRNA) (4), which is exported from the nucleus. Maturation of the pre-miRNA into miRNA is then mediated by the cytoplasmic enzyme Dicer (5), after which the mature miRNA is loaded into the RNA-induced silencing complex (RISC)

This study tested the hypothesis that pulsed electromagnetic field (PEMF) treatments augment and accelerate the healing of bone trauma. It utilized micro-computed tomography imaging of live rats that had received bilateral 0.2 mm fibular osteotomies (-0.5% acute bone loss) as a means to assess the in vivo rate dynamics of hard callus formation and overall callus volume. Starting 5 days post-surgery, osteotomized right hind limbs were exposed 3 h daily to Physio-Stim@ PEMF, 7 days a week for up to 5 weeks of treatment. The contralateral hind limbs served as sham-treated, within-animal internal controls. Although both PEMF-and sham-treatment groups exhibited similar onset of hard callus at -9days after surgery, a 2-fold faster rate of hard callus formation was observed thereafter in PEMF-treated limbs, yielding a 2-fold increase in callus volume by 13-20 days after surgery. The quantity of the new woven bone tissue within the osteotomy sites was significantly better in PEMF-treated versus sham-treated fibulae as assessed via hard tissue histology. The apparent modulus of each callus was assessed via a cantilever bend test and indicated a 2-fold increase in callus stiffness in the PEMF-treated over sham-treated fibulae. PEMF-treated fibulae exhibited an apparent modulus at the end of 5-weeks that was -80% that of unoperated fibulae. Overall, these data indicate that Physio-Stim@ PEMF treatment improved osteotomy repair. These beneficial effects on bone healing were not observed when a different PEMF waveform, Osteo-Stim@, was used. This latter observation demonstrates the specificity in the relationship between waveform characteristics and biological outcomes.

BackgroundCarbon dioxide (CO2) therapy refers to the transcutaneous administration of CO2 for therapeutic purposes. This effect has been explained by an increase in the pressure of O2 in tissues known as the Bohr effect. However, there have been no reports investigating the oxygen dissociation of haemoglobin (Hb) during transcutaneous application of CO2 in vivo. In this study, we investigate whether the Bohr effect is caused by transcutaneous application of CO2 in human living body.MethodsWe used a novel system for transcutaneous application of CO2 using pure CO2 gas, hydrogel, and a plastic adaptor. The validity of the CO2 hydrogel was confirmed in vitro using a measuring device for transcutaneous CO2 absorption using rat skin. Next, we measured the pH change in the human triceps surae muscle during transcutaneous application of CO2 using phosphorus-31 magnetic resonance spectroscopy (31P-MRS) in vivo. In addition, oxy- and deoxy-Hb concentrations were measured with near-infrared spectroscopy in the human arm with occulted blood flow to investigate O2 dissociation from Hb caused by transcutaneous application of CO2.ResultsThe rat skin experiment showed that CO2 hydrogel enhanced CO2 gas permeation through the rat skin. The intracellular pH of the triceps surae muscle decreased significantly 10 min. after transcutaneous application of CO2. The NIRS data show the oxy-Hb concentration decreased significantly 4 min. after CO2 application, and deoxy-Hb concentration increased significantly 2 min. after CO2 application in the CO2-applied group compared to the control group. Oxy-Hb concentration significantly decreased while deoxy-Hb concentration significantly increased after transcutaneous CO2 application.ConclusionsOur novel transcutaneous CO2 application facilitated an O2 dissociation from Hb in the human body, thus providing evidence of the Bohr effect in vivo.

HDAC1 is overexpressed in RA-SF compared to OA-SF. HDAC1 supports cell proliferation and survival of RA-SF, but suppresses MMP-1 production. HDAC2 also plays an important role in cell proliferation and apoptosis of RA-SF. Our study provides useful information to develop new HDAC inhibitors for the treatment of RA.

Hypertrophic nonunion usually results from insufficient fracture stabilization. Therefore, most hypertrophic nonunions simply require the stabilization of the nonunion site. However, the reasons why union occurs without treating the nonunion site directly is not well understood biologically. In this study, we hypothesized that the intervening tissue at the hypertrophic nonunion site (nonunion tissue) could serve as a reservoir of mesenchymal progenitor cells and investigated whether the cells derived from nonunion tissue had the capacity for multilineage mesenchymal differentiation. After nonunion tissue was obtained, it was cut into strips and cultured. Homogenous fibroblastic adherent cells were obtained. Flow cytometry revealed that the adherent cells were consistently positive for mesenchymal stem cell related markers CD13, CD29, CD44, CD90, CD105, CD166, and negative for the hematopoietic markers CD14, CD34, CD45, and CD133, similar to control bone marrow stromal cells. In the presence of lineage-specific induction factors, the adherent cells differentiated in vitro into osteogenic, chondrogenic, and adipogenic cells. These results demonstrated for the first time that hypertrophic nonunion tissue contains multilineage mesenchymal progenitor cells. This suggests that hypertrophic nonunion tissue plays an important role during the healing process of hypertrophic nonunion by serving as a reservoir of mesenchymal cells that are capable of transforming into cartilage and bone forming cells. ß

Xeroderma pigmentosum (XP) is a genetic photosensitive disorder in which patients are highly susceptibe to skin cancers on the sun-exposed body sites. In Japan, more than half of patients (30% worldwide) with XP show complications of idiopathic progressive, intractable neurological symptoms with poor prognoses. Therefore, this disease does not merely present with dermatological symptoms, such as photosensitivity, pigmentary change and skin cancers, but is "an intractable neurological and dermatological disease". For this reason, in March 2007, the Japanese Ministry of Health, Labor and Welfare added XP to the neurocutaneous syndromes that are subject to government research initiatives for overcoming intractable diseases. XP is one of the extremely serious photosensitive disorders in which patients easily develop multiple skin cancers if they are not completely protected from ultraviolet radiation. XP patients thus need to be strictly shielded from sunlight throughout their lives, and they often experience idiopathic neurodegenerative complications that markedly reduce the quality of life for both the patients and their families. Hospitals in Japan often see cases of XP as severely photosensitive in children, and as advanced pigmentary disorders of the sun-exposed area with multiple skin cancers in adults (aged in their 20-40s), making XP an important disease to differentiate in everyday clinical practice. It was thus decided that there was a strong need for clinical practice guidelines dedicated to XP. This process led to the creation of new clinical practice guidelines for XP.

Objective. To verify the effects of (-)-epigallocatechin-3-gallate (EGCG) on osteoclast differentiation and on experimental arthritis in mice.Methods. Human osteoclasts were differentiated from peripheral blood monocytes. The effects of EGCG were examined by tartrate-resistant acid phosphatase ( Conclusion. EGCG suppressed osteoclast differentiation and ameliorated experimental arthritis in mice over the short term. It remains to be established whether EGCG is useful for the prevention and treatment of osteoporosis and rheumatoid arthritis.

We isolated multilineage mesenchymal progenitor cells from haematomas collected from fracture sites. After the haematoma was manually removed from the fracture site it was cut into strips and cultured. Homogenous fibroblastic adherent cells were obtained. Flow cytometry revealed that the adherent cells were consistently positive for mesenchymal stem-cell-related markers CD29, CD44, CD105 and CD166, and were negative for the haemopoietic markers CD14, CD34, CD45 and CD133 similar to bone-marrow-derived mesenchymal stem cells. In the presence of lineage-specific induction factors the adherent cells could differentiate in vitro into osteogenic, chondrogenic and adipogenic cells. Our results indicate that haematomas found at a fracture site contain multilineage mesenchymal progenitor cells and play an important role in bone healing. Our findings imply that to enhance healing the haematoma should not be removed from the fracture site during osteosynthesis.