A Point Mutation of Tyr-759 in Interleukin 6 Family Cytokine Receptor Subunit gp130 Causes Autoimmune Arthritis

We generated a mouse line in which the src homology 2 domain–bearing protein tyrosine phosphatase (SHP)-2 binding site of gp130, tyrosine 759, was mutated to phenylalanine (gp130F759/F759). The gp130F759/F759 mice developed rheumatoid arthritis (RA)-like joint disease. The disease was accompanied by autoantibody production and accumulated memory/activated T cells and myeloid cells. Before the disease onset, the T cells were hyperresponsive and thymic selection and peripheral clonal deletion were impaired. The inhibitory effect of IL-6 on Fas ligand expression during activation-induced cell death (AICD) was augmented in gp130F759/F759 T cells in a manner dependent on the tyrosine residues of gp130 required for signal transducer and activator of transcription 3 activation. Finally, we showed that disease development was dependent on lymphocytes. These results provide evidence that a point mutation of a cytokine receptor has the potential to induce autoimmune disease

Applications of a Standardized Green Tea Catechin Preparation for Viral Warts and Human Papilloma Virus-Related and Unrelated Cancers

Most cell-based and animal experiments have shown that green tea catechins (GTC) exhibit various health benefits. In human experimental and epidemiological studies, there are conflicting results, and more precise investigations are required. One of the most effective ways to prove beneficial health effects in humans might be clinical intervention studies. Polyphenon®E was developed as a standardized GTC preparation, which was approved by Food and Drug Administration of US in 2006 as a medication to treat genital warts (Veregen® or sinecatechins). Positive efficacy of Polyphenon®E/sinecatechins/Veregen® (PSV) on anogenital warts has been demonstrated in several epidemiological studies and there have been several case reports to show the clinical effectiveness of PSV. In addition, several studies have provided evidence to suggest that PSV is effective in other human papillomavirus (HPV)-related diseases, although some studies failed to show such effects. Since (−)-epigallocatechin gallate (EGCG) is the major component of PSV, the mechanism of the action of PSV might be deduced from that of EGCG. The microarray analysis of the biopsy samples from the patients suggested that apoptosis induction and the downregulation of inflammation are involved in the mechanism of the action of PSV in the clearance of anogenital warts. Cell-based and animal experiments using PSV also demonstrated effects similar to those elicited by EGCG, explaining how PSV works to induce apoptosis and exert anti-inflammatory actions in HPV-related diseases. Future studies would clarify what kinds of diseases respond effectively to PSV, showing health benefits of GTC and EGCG in humans

Expression and Function of Transmembrane-4 Superfamily (Tetraspanin) Proteins in Osteoclasts: Reciprocal Roles of Tspan-5 and NET-6 during Osteoclastogenesis

Background: Osteoclasts are bone-resorbing multinuclear polykaryons essential for bone remodeling, formed through cell fusion of mononuclear macrophage/monocyte lineage precursor cells upon stimulation by the RANK/RANKL system. Recent studies have revealed that a family of tetraspanin proteins, such as CD9, is critically involved in the cell fusion/polykaryon formation of these cell types. Until now, however, there is limited knowledge about the types of tetraspanins expressed in osteoclasts and their precursors. Methods: The expression of different tetraspanin proteins in a monocyte/macrophage-lineage osteoclast precursor cell line, RAW264.7, was cyclopedically investigated using RT-PCR with specific primers and quantitative real-time RT-PCR. The function of two kinds of tetraspanins, Tspan-5 and NET-6, whose expression pattern was altered by RANKL stimulation, was examined by transfecting gene-specific short-interfering RNAs into these cell types. Results: Of the 17 tetraspanins in mammalian hematopoietic cells, RAW264.7 cells express mRNA for 12 different kinds of tetraspanins, namely, CD9, CD37, CD53, CD63, CD81, CD82, CD151, NAG-2, NET-6, SAS, Tspan-3, and Tspan-5. Interestingly, during their maturation into osteoclasts upon RANKL stimulation, the transcript for Tspan-5 is up-regulated, whereas that for NET-6 is down-regulated. Targeted inhibition of Tspan-5 by using gene-specific RNA interference suppressed RANKL-induced cell fusion during osteoclastogenesis, whereas inhibition of NET-6 augmented the osteoclastogenesis itself. These results suggest that Tspan-5 and NET-6 have a reciprocal function during osteoclastogenesis, i.e., positive and negative regulation by Tspan-5 and NET-6, respectively. RANKL regulates osteoclastogenesis by altering the balances of these tetraspanin proteins. Conclusions: These data indicate that a diversity of tetraspanins is expressed in osteoclast precursors, and that cell fusion during osteoclastogenesis is regulated by cooperation of distinct tetraspanin family proteins such as Tspan-5 and NET-6. This study indicates that functional alterations of tetraspanin family proteins may have therapeutic potential in diseases where osteoclasts play a major role, such as rheumatoid arthritis and osteoporosis

Effect of correction of hindfoot valgus deformity on ankle joint pain relief in rheumatoid arthritis cases: A report of two cases

We often see painful ankle joint destruction with painful hindfoot valgus deformity in rheumatoid arthritis. Our policy in such cases has been to first correct the hindfoot deformity in the subtalar joint with fusion, but then ankle joint pain has been observed. Two women with rheumatoid arthritis underwent correction and fusion surgery for hindfoot valgus deformity. They had been using wheelchairs because of severe pain in the ankle joint and hindfoot despite extensive medical treatment. After surgery, both patients complained of no pain in the hindfoot. Furthermore, dramatic pain reduction in the ankle joint was also observed especially in a case without ankle joint instability. Consequently, the patients could walk without any support. Correction of valgus hindfoot deformity contributes to centralizing the weight-bearing line in the ankle joint, leading to ankle joint pain relief. It appears possible to preserve the ankle joint without additional ankle surgery even in rheumatoid arthritis cases, if ankle is stable

Parathyroid hormone and premature thymus ageing in patients with chronic kidney disease

Abstract Premature immune ageing, including thymic atrophy, is observed in patients with chronic kidney disease (CKD). Parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF23), which are mineral and bone disorder (MBD)-related factors, affect immune cells and possibly cause thymic atrophy. We examined the cross-sectional association between thymic atrophy, evaluated as the number of CD3+CD4+CD45RA+CD31+ cells [recent thymic emigrants (RTE)/μL], and MBD-related factors [(serum PTH, FGF23, and alkaline phosphatase (ALP) level] in 125 patients with non-dialysis dependent CKD. Median estimated glomerular filtration rate (eGFR) was 17 mL/min/1.73 m2. Older age (r = −0.46), male sex (r = −0.34), lower eGFR (r = 0.27), lower serum-corrected calcium (r = 0.27), higher PTH (r = −0.36), and higher ALP level (r = −0.20) were identified as determinants of lower number of RTE. In contrast, serum concentrations of FGF23 and phosphorus were not correlated with RTE. Multivariate non-linear regression analysis indicated a negative association between serum PTH and log-transformed RTE (P = 0.030, P for non-linearity = 0.124). However, the serum levels of FGF23 and ALP were not associated with RTE. In patients with CKD, serum PTH concentrations were related to thymic atrophy which contributes to immune abnormality

Safety and efficacy of CT-P13 in Japanese patients with rheumatoid arthritis in an extension phase or after switching from infliximab

<p><i>Objectives</i>: This study aimed to evaluate the safety of CT-P13 in patients with rheumatoid arthritis (RA) during long-term treatment or after switching from innovator infliximab (IFX).</p> <p><i>Methods</i>: Patients who completed 54 weeks of treatment in a phase I/II study (PI/II) received CT-P13 at an initial dose of 3 mg/kg at Week 62, with dose increases permitted up to 10 mg/kg. The primary endpoint was adverse event (AE) incidence.</p> <p><i>Results</i>: Thirty-four of 38 patients in the maintenance group and 29 of 33 in the switch group reported at least one AE. Safety profiles in both groups were similar to those in PI/II. Eleven of 28 patients who were positive for anti-drug antibodies (ADA) at Week 62 discontinued the study before Week 110. Forty-one of 43 ADA-negative patients remained negative, and 10 of 28 ADA-positive patients became negative during the study. The mean DAS28 (ESR) at Week 134 was 3.166 in the maintenance group and 3.955 in the switch group.</p> <p><i>Conclusions</i>: CT-P13 was well tolerated in patients who maintained the treatment after 54 weeks and in patients who switched to CT-P13 after 54 weeks of IFX treatment. The study also demonstrated a stable clinical efficacy of CT-P13 in RA patients.</p