High oxygen tension prolongs the survival of osteoclast precursors via macrophage colony-stimulating factor

The oxygen tension affects the function, differentiation, and transformation of various cells, including bone cells. In pathological conditions such as rheumatoid arthritis (RA), rapidly destructive arthropathy, and primary or metastatic tumors, severe bone destruction or osteolysis occurs. Abundant blood vessels are often observed around these destructive lesions. At such sites, we have confirmed the increased production of reactive oxygen species (ROS) induced by a high oxygen tension and/or oxidative stress, as well as numerous osteoclasts detectable by immunohistochemistry. These findings suggest that osteoclasts are influenced by the high oxygen tension in pathological bone lesions because the zone around blood vessels has a relatively high oxygen tension. In this study, we investigated the effects of oxygen tension on osteoclastogenesis by culturing human CD14-positive cells (osteoclast precursors) with or without osteoblast-like supporting cells (Saos-4/3 cells) under a normal oxygen tension (20% O(2)) or a high oxygen tension (40% O(2)). A high oxygen tension markedly prolonged the duration of osteoclast precursor formation in the presence of supporting cells, and also markedly and persistently increased the production of macrophage colony stimulating factor (M-CSF) by supporting cells. Furthermore, we found an increase of cells expressing M-CSF and cells positive for tartrate-resistant acid phosphatase (TRAP) in hypervascular destructive bone lesions of RA patients where ROS were also abundant.     

T-cell leukemia translocation-associated gene (TCTA) protein is required for human osteoclastogenesis

Synovial tissues of patients with rheumatoid arthritis (RA) include factors regulating bone resorption, such as receptor activator NF-κB ligand (RANKL), TNFα, IL-6, IL-17 and IFNγ. However, in addition to these cytokines, other factors expressed in synovial tissues may play a role in resorbing bone. Here, our objective was to identify novel proteins expressed in synovial tissues of RA that regulate human osteoclastogenesis. Proteins were purified from synovial tissues of patients with RA, using gel filtration chromatography, ion-exchange chromatography, reverse-aspect HPLC, and mass spectrometry. We evaluated the effects of the purified fractions on human osteoclastogenesis induced by RANKL and M-CSF. We determined the amino acid sequences showing inhibitory activity on human osteoclastogenesis. In addition, we synthesized novel peptides from the molecule including the amino acid sequences. Then, we evaluated the effects of the peptides and antibodies against the molecule on human osteoclastogenesis from monocytes and mature osteoclasts, and on pit formation by mature osteoclasts using Osteologic^R discs. We examined the effect of the peptide on the expression of both mRNA and protein of NFATc1. We also examined the effect of RANKL on the expression of mRNA of the molecule on osteoclasts and macrophages. We identified a small peptide including Gly-Gln-Asn (GQN) with inhibitory activity on human osteoclastogenesis. We then found that GQN is included in the amino acid sequence of the extra-cellular domain of TCTA protein, which is expressed ubiquitously in normal human tissues, but whose function has not been clarified. We designed novel peptides, including GQN, from the sequence of TCTA protein. One of these peptides (29-mer), but not a scrambled peptide for the 29-mer peptide, potently inhibited RANKL-induced human osteoclastogenesis. The peptide also inhibited pit formation of mature human osteoclasts and suppressed the formation of large osteoclasts in the culture of mature osteoclasts. Furthermore, polyclonal antibodies against TCTA protein suppressed the formation of large osteoclasts in the cultures of both monocytes and mature osteoclasts, supporting our hypothesis. Peptide A did not significantly inhibit the expression of both mRNA and protein of NFATc1 in osteoclasts. Our novel peptide and polyclonal antibodies against the peptide inhibited human osteoclastogenesis and the function of mature osteoclasts, preventing cellular fusion by TCTA protein and a putative counterpart molecule.     

Molecular genetic analysis of BAX and cyclin D1 genes in patients with malignant glioma

INTRODUCTION AND OBJECTIVES: Brain tumorigenesis is a complex process involving multiple genetic alterations. Cyclin D1 and BAX genes are two of the most important regulators in controlling the normal proliferation and apoptosis of cells, respectively. In this study, we analysed the possibilities of involvement of cyclin D1 and BAX genes in the gliomagenesis. METHODS AND RESULTS: In determining gene alterations of exon 4 of cyclin D1 gene and exon 6 of BAX gene, all samples were amplified by polymerase chain reaction (PCR) and subsequently by direct sequencing. Our results showed a frameshift mutation (G base deletion) at nucleotide 82 of codon 28 in exon 4 of the cyclin D1 gene and another frameshift mutation with a deletion of C base at nucleotide 153 of exon 6 of the BAX gene in two separate cases of a glioblastoma multiform (WHO Grade IV) sample. CONCLUSION: These findings suggest that both cyclin D1 and BAX genes alteration are rarely found in brain tumors. However, the alteration might cause a significant effect of the normal protein production and this might contribute to the development of brain tumorigenesis in Malaysian patients.     

Stalking,and Social and Romantic Functioning Among Adolescents and Adults with Autism Spectrum Disorder

We examine the nature and predictors of social and romantic functioning in adolescents and adults with ASD. Parental reports were obtained for 25 ASD adolescents and adults (13–36 years), and 38 typical adolescents and adults (13–30 years). The ASD group relied less upon peers and friends for social (OR = 52.16, p < .01) and romantic learning (OR = 38.25, p < .01). Individuals with ASD were more likely to engage in inappropriate courting behaviours (χ² _{df = 19} = 3168.74, p < .001) and were more likely to focus their attention upon celebrities, strangers, colleagues, and ex-partners (χ² _{df = 5} = 2335.40, p < .001), and to pursue their target longer than controls (t = −2.23, df = 18.79, p < .05). These results show that the diagnosis of ASD is pertinent when individuals are prosecuted under stalking legislation in various jurisdictions.     

Cerebral inhibitory functioning in patients with attention deficit/hyperactivity disorder. I. Analysis of non-target-P300 component in a visual oddball paradigm

The present study was organized to evaluate the cerebral inhibitory function in children with developmental disorders such as attention deficit/hyperactivity disorder (AD/HD) and pervasive developmental disorder (PDD). Target and non-target-P300 event related potential (ERP) in response to stimuli of a visual oddball paradigm was analyzed. Ten children with AD/HD, 10 children with PDD and 10 healthy children were included in the study participants. Target-P300 component was observed in all subjects, which showed predominant amplitudes in Pz electrode. No significant differences were observed in amplitude and latency of target-P300 among three groups. In healthy children, Non-target-P300 component was observed mainly in Cz and Pz electrodes, while children with AD/HD had significantly reduced amplitudes of the component at Cz and children with PDD showed shorter latency at Oz. These results suggest that Non-target-P300 component in visual oddball paradigm possibly reflects the brain function associated with inhibitory processing and there is a relationship between the non-target-P300 potential abnormality and the AD/HD behavior.