Leucine-rich alpha-2 glycoprotein as a potential biomarker for large vessel vasculitides

Objectives

Serum levels of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) have been used as useful biomarkers for reflecting the activity of large vessel vasculitides (LVV). However, a novel biomarker that could have a complementary role to these markers is still required. In this retrospective observational study, we investigated whether leucine-rich α-2 glycoprotein (LRG), a known biomarker in several inflammatory diseases, could be a novel biomarker for LVVs.

Methods

49 eligible patients with Takayasu arteritis (TAK) or giant cell arteritis (GCA) whose serum was preserved in our laboratory were enrolled. The concentrations of LRG were measured with an enzyme-linked immunosorbent assay. The clinical course was reviewed retrospectively from their medical records. The disease activity was determined according to the current consensus definition.

Results

The serum LRG levels were higher in patients with active disease than those in remission, and decreased after the treatments. While LRG levels were positively correlated with both CRP and erythrocyte sedimentation rate, LRG exhibited inferior performance as an indicator of disease activity compared to CRP and ESR. Of 35 CRP-negative patients, 11 had positive LRG. Among the 11 patients, two had active disease.

Conclusion

This preliminary study indicated that LRG could be a novel biomarker for LVV. Further large studies should be required to promise the significance of LRG in LVV.

Amelioration of inflammatory myopathies by glucagon-like peptide-1 receptor agonist via suppressing muscle fibre necroptosis

BACKGROUND

As glucocorticoids induce muscle atrophy during the treatment course of polymyositis (PM), novel therapeutic strategy is awaited that suppresses muscle inflammation but retains muscle strength. We recently found that injured muscle fibres in PM undergo FASLG-mediated necroptosis, a form of regulated cell death accompanied by release of pro-inflammatory mediators, contributes to accelerate muscle inflammation and muscle weakness. Glucagon-like peptide-1 receptor (GLP-1R) agonists have pleiotropic actions including anti-inflammatory effects, prevention of muscle atrophy, and inhibition of cell death, in addition to anti-diabetic effect. We aimed in this study to examine the role of GLP-1R in PM and the effect of a GLP-1R agonist on in vivo and in vitro models of PM.

METHODS

Muscle specimens of PM patients and a murine model of PM, C protein-induced myositis (CIM), were examined for the expression of GLP-1R. The effect of PF1801, a GLP-1R agonist, on CIM was evaluated in monotherapy or in combination with prednisolone (PSL). As an in vitro model of PM, C2C12-derived myotubes were treated with FASLG to induce necroptosis. The effect of PF1801 on this model was analysed.

RESULTS

GLP-1R was expressed on the inflamed muscle fibres of PM and CIM. The treatment of CIM with PF1801 in monotherapy (PF) or in combination with PSL (PF + PSL) suppressed CIM-induced muscle weakness (grip strength, mean ± SD (g); PF 227 ± 6.0 (P < 0.01), PF + PSL 224 ± 8.5 (P < 0.01), Vehicle 162 ± 6.0) and decrease in cross-sectional area of muscle fibres (mean ± SD (μm² ); PF 1896 ± 144 (P < 0.05), PF + PSL 2018 ± 445 (P < 0.01), Vehicle 1349 ± 199) as well as the severity of histological inflammation scores (median, interquartile range; PF 0.0, 0.0-0.5 (P < 0.05), PF + PSL 0.0, 0.0-0.0 (P < 0.01), Vehicle 1.9, 1.3-3.3). PF1801 decreased the levels of inflammatory mediators such as TNFα, IL-6, and HMGB1 in the serum of CIM. PF1801 inhibited necroptosis of the myotubes in an AMP-activated protein kinase (AMPK)-dependent manner. PF1801 activated AMPK and decreased the expression of PGAM5, a mitochondrial protein, which was crucial for necroptosis of the myotubes. PF1801 promoted the degradation of PGAM5 through ubiquitin-proteasome activity. Furthermore, PF1801 suppressed FASLG-induced reactive oxygen species (ROS) accumulation in myotubes, also crucial for the execution of necroptosis, thorough up-regulating the antioxidant molecules including Nfe2l2, Hmox1, Gclm, and Nqo1.

CONCLUSIONS

GLP-1R agonist could be a novel therapy for PM that recovers muscle weakness and suppresses muscle inflammation through inhi biting muscle fibre necroptosis.

POS0472 AGONISTIC STIMULATION OF GLUCAGON-LIKE PEPTIDE-1 RECEPTOR AMELIORATED INFLAMMATORY MYOPATHIES THROUGH SUPPRESSING MUSCLE FIBER NECROPTOSIS

Background

While glucocorticoids (GC) are the cornerstone of the treatment for polymyositis (PM), GC-induced myopathy is inevitable, which further deteriorates muscle weakness. Therefore, novel therapeutic strategy that not only suppresses muscle inflammation but also improves muscle strength is awaited. We recently found that injured muscle fibers in PM undergo FASLG-mediated necroptosis1, a form of regulated cell death accompanied with release of pro-inflammatory mediators such as HMGB1, which contributes to accelerate muscle inflammation and muscle weakness. We also showed that inhibition of necroptosis or HMGB1 ameliorated the muscle weakness and muscle inflammation1 in C protein-induced myositis (CIM), a murine model of PM. Glucagon-like peptide-1 receptor (GLP-1R) agonists, which have been developed as an anti-diabetic therapy, have pleiotropic actions including anti-inflammatory effects2, suppression of muscle wasting3, and inhibition of cell death4. Accordingly, we hypothesized that GLP-1R agonists have beneficial effects on PM to recover muscle strength and to suppress muscle inflammation.

Objectives

The aims of this study are to examine the role of GLP-1R in PM and the effect of a GLP-1R agonist on in vivo and in vitro models of PM.

Methods

Muscle specimens of PM patients and CIM were examined with immunofluorescence staining for the expression of GLP-1R. The effect of PF1801, a GLP-1R agonist, on CIM was examined in monotherapy or in combination with prednisolone (PSL). As an in vitro model of PM, C2C12-derived myotubes were treated with FAS ligand (FASLG) to induce necroptosis. The levels of HMGB1, TNF-α, and IL-6 in the serum of CIM and in the culture supernatant of the in vitro model were measured by ELISA. The effect of PF1801 on the myotube necroptosis was examined using time lapse imaging 5 and its effect on the activation of AMP-activated protein kinase (AMPK), the expression of PGAM5, and ubiquitination of PGAM5 was assessed with immunoblotting. The levels of reactive oxygen species (ROS) in the myotubes were analyzed with CellROX assay. The effect of PF1801 on the expression of antioxidant molecules in the myotubes was analyzed with quantitative real-time PCR.

Results

GLP-1R was expressed on the inflamed muscle fibers of PM and CIM. The treatment with PF1801 in monotherapy or in combination with PSL suppressed CIM-induced muscle weakness and the muscle weight loss as well as the severity of histological myositis while the monotherapy with PSL did not suppress muscle weakness and muscle weight loss. PF1801 decreased the levels of inflammatory mediators such as HMGB1, TNF-α, and IL-6 in the serum of CIM. In vitro, PF1801 inhibited FASLG-induced myotube necroptosis and decreased the levels of HMGB1, TNF-α, and IL-6 in the supernatant. PF1801 activated AMPK and decreased the levels of PGAM5, which was crucial for FASLG-induced necroptosis of the myotubes. The inhibitory effect of PF1801 on myotube necroptosis was cancelled by compound C, an AMPK-kinase inhibitor, or MG132, a proteasome inhibitor, suggesting that PF1801 promoted ubiquitin-proteasome-mediated PGAM5 degradation through the activation of AMPK. Furthermore, PF1801 suppressed FASLG-induced reactive oxygen species (ROS) accumulation in myotubes, which was also crucial for the execution of necroptosis, thorough up-regulating the antioxidant molecules such as Nfe2l2, Hmox1, Gclm, and Nqo1.

Conclusion

GLP-1R agonist could be a novel therapy for PM that restores muscle strength as well as suppresses muscle inflammation through inhibiting muscle fiber necroptosis.

References

[1]Kamiya M, et al. Nat Commun. 2022;13:166

[2]Du X, et al. Int Immunopharmacol. 2019;75:105732.

[3]Hong Y, et al. J Cachexia Sarcopenia Muscle. 2019;10:903–918.

[4]Younce CW, et al. Am J Physiol - Cell Physiol. 2013;304:508–518.

[5]Kamiya M, et al. Rheumatology (Oxford). 2020; 59:224-232

Acknowledgements

We thank Katsuko Yamasaki for the histological analysis.

Disclosure of Interests

Mari Kamiya Speakers bureau: Pfizer and Ono Pharmaceutical, Grant/research support from: GlaxoSmithKline, Fumitaka Mizoguchi Speakers bureau: AbbVie, Asahi Kasei Pharma, Bristol-Myers Squibb, Chugai Pharmaceutical, Eizai, Eli Lilly and Company, Glaxo Smith Kline, Ono Pharmaceutical, and Pfizer., Consultant of: Asahi Kasei Pharma and ImmunoForge., Grant/research support from: AbbVie, Astellas Pharma, Bristol-Myers Squibb, Chugai Pharmaceutical, Daiichi Sankyo Company, Eisai, Eli Lilly and Company, ImmunoForge, Japan Blood Products Organization, Mitsubishi Tanabe Pharma, Novartis Pharma Japan, Ono Pharmaceutical, Otsuka Pharmaceutical Factory, Pfizer, Sanofi, Takeda Pharmaceutical Company and Teijin, Hirokazu Sasaki: None declared, Natsuka Umezawa: None declared, Shinsuke Yasuda Speakers bureau: Abbvie, Asahi Kasei Pharma, Chugai Pharmaceutical, Eisai, Eli Lilly, GlaxoSmithKline, Mitsubishi Tanabe Pharma, Ono pharmaceutical, and Pfizer., Consultant of: ImmunoForge, Grant/research support from: Abbvie, Asahi Kasei Pharma, Chugai Pharmaceutical, CSL Behring, Eisai, ImmunoForge, Mitsubishi Tanabe Pharma, and Ono pharmaceutical.

Therapeutic effect of cyclin-dependent kinase 4/6 inhibitor on dermal fibrosis in murine models of systemic sclerosis

OBJECTIVE

Histology of systemic sclerosis (SSc) includes an increased number of myofibroblasts, where transforming growth factor-β (TGF-β) plays a crucial role to promote dermal fibrosis. The objectives of this study were to examine whether the inhibition of cell cycle with cyclin-dependent kinase (CDK) 4/6 inhibitor suppress fibroblast proliferation and the differentiation into myofibroblasts, and the therapeutic effect of a CDK4/6 inhibitor on dermal fibrosis in murine models of SSc in monotherapy or in combination with TGF-β receptor inhibitor (TGFβRI).

METHODS

SSc fibroblasts were cultured in the presence or absence of TGF-β. Effects of palbociclib (CDKI), a CDK4/6 inhibitor, on fibroblast proliferation and TGF-β-induced differentiation into myofibroblasts were examined with BrdU uptake, immunofluorescence, and immunoblotting. Hypochlorous acid (HOCl)- and bleomycin-induced dermal fibrosis models were used to study the effect of CDKI on dermal fibrosis in monotherapy or in combination with galunisertib, a TGFβRI.

RESULTS

CDKI suppressed the proliferation of SSc fibroblasts and their TGF-β-induced differentiation into myofibroblast without inhibiting canonical and non-canonical TGF-β signals. Treatment of dermal fibrosis models with CDKI decreased dermal thickness and collagen content, as well as fibroblast proliferation and myofibroblast number. The combination therapy with CDKI and TGFβRI exerted additive anti-fibrotic effects. Mechanistically, CDKI suppressed the expression of cellular communication network (CCN) 2 and cadherin-11 important for fibrosis.

CONCLUSION

We demonstrated the therapeutic effect of CDKI on dermal fibrosis in monotherapy or in combination with TGFβRI. CDKI should be a novel agent for the treatment of SSc, which may be used with TGFβRI to increase the efficacy.

Chondroprotective effects of CDK4/6 inhibition via enhanced ubiquitin-dependent degradation of JUN in synovial fibroblasts

OBJECTIVE

Targeting synovial fibroblasts (SF) using a cyclin-dependent kinase (CDK) 4/6 inhibitor (CDKI) could be a potent therapy for rheumatoid arthritis (RA) via inhibition of proliferation and MMP-3 production. This study was designed to elucidate the mechanism of chondroprotective effects on SFs by CDK 4/6 inhibition.

METHODS

CDK4/6 activity was inhibited using CDKI treatment or enhanced by adenoviral gene transduction. Chondroprotective effects were evaluated using a collagen induced arthritis model (CIA). Gene and protein expression were evaluated with quantitative PCR, ELISA, and Western blotting. The binding of nuclear extracts to DNA was assessed with an electrophoresis mobility shift assay. RNA-Seq was performed to identify gene sets affected by CDKI treatment.

RESULTS

CDKI attenuated cartilage destruction and MMP-3 production in CIA. In RASFs, CDKI impaired the binding of AP-1 components to DNA and inhibited the production of MMP-1 and MMP-3, which contain the AP-1 binding sequence in their promoter. CDK4/6 protected JUN from proteasome-dependent degradation by inhibiting ubiquitination. The RNA-Seq analysis identified CDKI-sensitive inflammatory genes, which were associated with the pathway of RA-associated genes, cytokine-cytokine receptor interaction, and IL-17 signalling. Notably, the AP-1 motif was enriched in these genes.

CONCLUSION

The mechanism of chondroprotective effects by CDK4/6 inhibition was achieved by the attenuation of AP-1 transcriptional activity via the impaired stability of JUN. Since the pharmacologic inhibition of CDK4/6 has been established as tolerable in cancer treatment, it could also be beneficial in patients with RA due to its chondroprotective and anti-inflammatory effects.

Similarity of Response to Biologics Between Elderly-onset Rheumatoid Arthritis (EORA) and Non-EORA Elderly Patients: From the FIRST Registry

OBJECTIVE

Increasing numbers of patients are developing rheumatoid arthritis (RA) at an older age, and optimal treatment of patients with elderly-onset RA (EORA) is attracting greater attention. This study aimed to analyze the efficacy and safety of biologic/targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs) in EORA and non-EORA elderly patients.

METHODS

A cohort of patients with RA treated with b/tsDMARDs were retrospectively analyzed. Only patients aged ≥ 60 years were included. Among them, patients who developed RA aged ≥ 60 years were categorized as EORA, whereas those aged < 60 years were categorized as non-EORA elderly. Disease activity was compared between the EORA and non-EORA elderly groups.

RESULTS

In total, 1040 patients were categorized as EORA and 710 as non-EORA elderly. There were no significant differences in characteristics at baseline between the 2 groups. The proportion of patients with low and high disease activity was comparable at Weeks 2, 22, and 54 between the EORA and the non-EORA elderly group. There were no significant differences in the reasons for the discontinuation of b/tsDMARDs between the 2 groups. Elderly RA onset did not affect changes in Clinical Disease Activity Index (CDAI) and Health Assessment Questionnaire-Disability Index, nor did it affect the reasons for b/tsDMARD discontinuation between the 2 groups. The trajectory analysis on CDAI responses to b/tsDMARDs for 54 weeks identified 3 response patterns. The proportion of patients categorized into each group and CDAI response trajectories to b/tsDMARDs were very similar between EORA and non-EORA elderly patients.

CONCLUSION

CDAI response patterns to b/tsDMARDs and HR of adverse events were similar between EORA and non-EORA elderly patients.

SAT0295 GLUCAGON-LIKE PEPTIDE-1 RECEPTOR AGONIST AMELIORATED MUSCLE WEAKNESS AND INFLAMMATION IN EXPERIMENTAL POLYMYOSITIS

Background:

Polymyositis (PM) is a chronic inflammatory myopathy that impairs muscle functions. While the treatment with glucocorticoids (GC) has been the cornerstone of the treatment for PM to suppress immune-mediated muscle injury, some patients suffer from glucocorticoid-induced myopathy during the treatment, which further deteriorates the muscle weakness. It has been reported that significant disability and muscle weakness persist in a quarter of the patients even after successful treatment with the immunosuppressive therapy1. Ultimately, new therapeutic strategies to preserve and recover muscle strength as well as to suppress immune-mediated muscle injury are needed. Glucagon-like peptide-1 (GLP-1) is a peptide hormone with a variety of functions. Although GLP-1 receptor (GLP-1R) agonists have been developed as an anti-diabetic therapy to promote insulin secretion, emerging data suggest that they have pleiotropic actions including anti-inflammatory effects and suppression of muscle wasting2. We presumed that GLP-1R agonists have beneficial effect on PM to preserve and recover muscle strength.

Objectives:

To examine the effect of a GLP-1R agonist on C protein-induced myositis (CIM), a murine model of polymyositis3, in monotherapy or in combination with prednisolone (PSL).

Methods:

Muscle specimens of PM patients and CIM were examined with immunohistological staining for the expression of GLP-1R. The therapeutic effect of PF1801 (ImmunoForge), a GLP-1R agonist (5 mg/kg body weight (BW)/day), in monotherapy or in combination with PSL (20 mg/kg BW/day) on CIM was examined for grip strength, muscle weight and histological muscle inflammation.

Results:

GLP-1R was expressed on the plasma membrane of muscle cells of PM patients and CIM. The expression levels were high in the area where inflammatory infiltrates were observed. The treatment of CIM with PF1801 in monotherapy or in combination with PSL suppressed the CIM-induced decrease in grip strength on day 14. The combination therapy with PF1801 and PSL ameliorated the CIM-induced muscle weight loss in quadriceps, while the monotherapy with PF1801 or PSL did not. The histological analysis of muscle specimens on day 14 of CIM revealed that the muscle inflammation was suppressed by the treatments with PF1801, PSL, or the combination of PF1801 and PSL. None of the mice in the combination therapy group developed histologically evident myositis, while the myositis was observed in 90%, 40% and 40 % of the mice in vehicle treated group, PF1801 treated group, and PSL treated group, respectively. The necrotic area of the muscle in CIM was also reduced in the mice treated with PF1801, PSL, or the combination of PSL and PF1801. The CIM-induced increase in spleen weight was suppressed by PF1801, PSL, or the combination of PSL and PF1801. The additive effect of PSL and PF1801 on the suppression of CIM-induced increase in spleen weight was observed.

Conclusion:

PF1801 ameliorated CIM-induced muscle weakness and muscle inflammation in CIM. The combination therapy with PF1801 and PSL ameliorated CIM-induced muscle weight loss. PF1801 could be a novel therapy to recover muscle weakness and to suppress muscle inflammation in PM.

References:

[1]Bronner IM, et al.Ann Rheum Dis.2006;65:1456–61.

[2]Hong Y, et al.J Cachexia Sarcopenia Muscle. 2019;10:903-18.

[3]Sugihara T, et al.Arthritis Rheum. 2007;56:1304-14.

Disclosure of Interests:

Mari Kamiya: None declared, Seon Uk Kim: None declared, Jeong Yeon Kim: None declared, Yeong Wook Song: None declared, Eun Young Lee: None declared, Fumitaka Mizoguchi Grant/research support from: ImmunoForge, Consultant of: ImmunoForge

Synoviocyte-targeted therapy synergizes with TNF inhibition in arthritis reversal

Fibroblast-like synoviocytes (FLS) are joint-lining cells that promote rheumatoid arthritis (RA) pathology. Current disease-modifying antirheumatic agents (DMARDs) operate through systemic immunosuppression. FLS-targeted approaches could potentially be combined with DMARDs to improve control of RA without increasing immunosuppression. Here, we assessed the potential of immunoglobulin-like domains 1 and 2 (Ig1&2), a decoy protein that activates the receptor tyrosine phosphatase sigma (PTPRS) on FLS, for RA therapy. We report that PTPRS expression is enriched in synovial lining RA FLS and that Ig1&2 reduces migration of RA but not osteoarthritis FLS. Administration of an Fc-fusion Ig1&2 attenuated arthritis in mice without affecting innate or adaptive immunity. Furthermore, PTPRS was down-regulated in FLS by tumor necrosis factor (TNF) via a phosphatidylinositol 3-kinase-mediated pathway, and TNF inhibition enhanced PTPRS expression in arthritic joints. Combination of ineffective doses of TNF inhibitor and Fc-Ig1&2 reversed arthritis in mice, providing an example of synergy between FLS-targeted and immunosuppressive DMARD therapies.

Insensitivity versus poor response to tumour necrosis factor inhibitors in rheumatoid arthritis: a retrospective cohort study

Background

With advancement in the treatment options of rheumatoid arthritis (RA), optimising the outcomes of difficult-to-treat patients has become increasingly important in clinical practice. In particular, insensitivity to first-line biologic disease-modifying anti-rheumatic drugs (bDMARD) is becoming a significant problem because it may decrease the treatment adherence of patients. This study aimed to compare RA patients with an insensitivity and those with a poor response to initial treatment with tumour necrosis factor inhibitors (TNFis), which are the most frequently used bDMARDs.

Methods

This is a retrospective cohort study using clinical data from the FIRST registry. bDMARD-naïve RA patients treated with tumour necrosis factor inhibitors (TNFis) from August 2003 to May 2019 were included and categorised into three groups: TNFi insensitivity, poor response to TNFis and controls. TNFi insensitivity was defined as follows: (1) discontinuation of TNFi treatment within 22 weeks due to lack of any response, or (2) an increase in the disease activity score in 28 joints–C-reactive protein (DAS28-CRP) of > 0.6 at week 22 compared with week 0. Among the remaining patients, those with a DAS28-CRP > 2.6 at week 22 were categorised in the poor response group.

Results

Of the included patients, 94 were classified in the insensitivity, 604 in the poor response and 915 in the control. A higher DAS28-CRP before treatment was a risk factor for a poor response but not for insensitivity. In contrast, dose escalation of infliximab decreased the risk of a poor response but not that of insensitivity.

Conclusions

In future research, poor and insensitivity to bDMARDs should be assessed separately to fully elucidate the aetiology of, and risk factors for, bDMARD refractoriness.

A new in vitro model of polymyositis reveals CD8+ T cell invasion into muscle cells and its cytotoxic role

Objectives

The hallmark histopathology of PM is the presence of CD8⁺ T cells in the non-necrotic muscle cells. The aim of this study was to clarify the pathological significance of CD8⁺ T cells in muscle cells.

Methods

C2C12 cells were transduced retrovirally with the genes encoding MHC class I (H2K^b) and SIINFEKL peptide derived from ovalbumin (OVA), and then differentiated to myotubes (H2K^bOVA-myotubes). H2K^bOVA-myotubes were co-cultured with OT-I CD8⁺ T cells derived from OVA-specific class I restricted T cell receptor transgenic mice as an in vitro model of PM to examine whether the CD8⁺ T cells invade into the myotubes and if the myotubes with the invasion are more prone to die than those without. Muscle biopsy samples from patients with PM were examined for the presence of CD8⁺ T cells in muscle cells. The clinical profiles were compared between the patients with and without CD8⁺ T cells in muscle cells.

Results

Analysis of the in vitro model of PM with confocal microscopy demonstrated the invasion of OT-I CD8⁺ T cells into H2K^bOVA-myotubes. Transmission electron microscopic analysis revealed an electron-lucent area between the invaded CD8⁺ T cell and the cytoplasm of H2K^bOVA-myotubes. The myotubes invaded with OT-I CD8⁺ T cells died earlier than the uninvaded myotubes. The level of serum creatinine kinase was higher in patients with CD8⁺ T cells in muscle cells than those without these cells.

Conclusion

CD8⁺ T cells invade into muscle cells and contribute to muscle injury in PM. Our in vitro model of PM is useful to examine the mechanisms underlying muscle injury induced by CD8⁺ T cells.

Robust and highly efficient hiPSC generation from patient non-mobilized peripheral blood-derived CD34+ cells using the auto-erasable Sendai virus vector

BACKGROUND

Disease modeling with patient-derived induced pluripotent stem cells (iPSCs) is a powerful tool for elucidating the mechanisms underlying disease pathogenesis and developing safe and effective treatments. Patient peripheral blood (PB) cells are used for iPSC generation in many cases since they can be collected with minimum invasiveness. To derive iPSCs that lack immunoreceptor gene rearrangements, hematopoietic stem and progenitor cells (HSPCs) are often targeted as the reprogramming source. However, the current protocols generally require HSPC mobilization and/or ex vivo expansion owing to their sparsity at the steady state and low reprogramming efficiencies, making the overall procedure costly, laborious, and time-consuming.

METHODS

We have established a highly efficient method for generating iPSCs from non-mobilized PB-derived CD34+ HSPCs. The source PB mononuclear cells were obtained from 1 healthy donor and 15 patients and were kept frozen until the scheduled iPSC generation. CD34+ HSPC enrichment was done using immunomagnetic beads, with no ex vivo expansion culture. To reprogram the CD34+-rich cells to pluripotency, the Sendai virus vector SeVdp-302L was used to transfer four transcription factors: KLF4, OCT4, SOX2, and c-MYC. In this iPSC generation series, the reprogramming efficiencies, success rates of iPSC line establishment, and progression time were recorded. After generating the iPSC frozen stocks, the cell recovery and their residual transgenes, karyotypes, T cell receptor gene rearrangement, pluripotency markers, and differentiation capability were examined.

RESULTS

We succeeded in establishing 223 iPSC lines with high reprogramming efficiencies from 15 patients with 8 different disease types. Our method allowed the rapid appearance of primary colonies (~ 8 days), all of which were expandable under feeder-free conditions, enabling robust establishment steps with less workload. After thawing, the established iPSC lines were verified to be pluripotency marker-positive and of non-T cell origin. A majority of the iPSC lines were confirmed to be transgene-free, with normal karyotypes. Their trilineage differentiation capability was also verified in a defined in vitro assay.

CONCLUSION

This robust and highly efficient method enables the rapid and cost-effective establishment of transgene-free iPSC lines from a small volume of PB, thus facilitating the biobanking of patient-derived iPSCs and their use for the modeling of various diseases.

Methods for high-dimensional analysis of cells dissociated from cryopreserved synovial tissue

Background

Detailed molecular analyses of cells from rheumatoid arthritis (RA) synovium hold promise in identifying cellular phenotypes that drive tissue pathology and joint damage. The Accelerating Medicines Partnership RA/SLE Network aims to deconstruct autoimmune pathology by examining cells within target tissues through multiple high-dimensional assays. Robust standardized protocols need to be developed before cellular phenotypes at a single cell level can be effectively compared across patient samples.

Methods

Multiple clinical sites collected cryopreserved synovial tissue fragments from arthroplasty and synovial biopsy in a 10% DMSO solution. Mechanical and enzymatic dissociation parameters were optimized for viable cell extraction and surface protein preservation for cell sorting and mass cytometry, as well as for reproducibility in RNA sequencing (RNA-seq). Cryopreserved synovial samples were collectively analyzed at a central processing site by a custom-designed and validated 35-marker mass cytometry panel. In parallel, each sample was flow sorted into fibroblast, T-cell, B-cell, and macrophage suspensions for bulk population RNA-seq and plate-based single-cell CEL-Seq2 RNA-seq.

Results

Upon dissociation, cryopreserved synovial tissue fragments yielded a high frequency of viable cells, comparable to samples undergoing immediate processing. Optimization of synovial tissue dissociation across six clinical collection sites with ~ 30 arthroplasty and ~ 20 biopsy samples yielded a consensus digestion protocol using 100 μg/ml of Liberase™ TL enzyme preparation. This protocol yielded immune and stromal cell lineages with preserved surface markers and minimized variability across replicate RNA-seq transcriptomes. Mass cytometry analysis of cells from cryopreserved synovium distinguished diverse fibroblast phenotypes, distinct populations of memory B cells and antibody-secreting cells, and multiple CD4⁺ and CD8⁺ T-cell activation states. Bulk RNA-seq of sorted cell populations demonstrated robust separation of synovial lymphocytes, fibroblasts, and macrophages. Single-cell RNA-seq produced transcriptomes of over 1000 genes/cell, including transcripts encoding characteristic lineage markers identified.

Conclusions

We have established a robust protocol to acquire viable cells from cryopreserved synovial tissue with intact transcriptomes and cell surface phenotypes. A centralized pipeline to generate multiple high-dimensional analyses of synovial tissue samples collected across a collaborative network was developed. Integrated analysis of such datasets from large patient cohorts may help define molecular heterogeneity within RA pathology and identify new therapeutic targets and biomarkers.

Electronic supplementary material

The online version of this article (10.1186/s13075-018-1631-y) contains supplementary material, which is available to authorized users.

Functionally distinct disease-associated fibroblast subsets in rheumatoid arthritis

Fibroblasts regulate tissue homeostasis, coordinate inflammatory responses, and mediate tissue damage. In rheumatoid arthritis (RA), synovial fibroblasts maintain chronic inflammation which leads to joint destruction. Little is known about fibroblast heterogeneity or if aberrations in fibroblast subsets relate to pathology. Here, we show functional and transcriptional differences between fibroblast subsets from human synovial tissues using bulk transcriptomics of targeted subpopulations and single-cell transcriptomics. We identify seven fibroblast subsets with distinct surface protein phenotypes, and collapse them into three subsets by integrating transcriptomic data. One fibroblast subset, characterized by the expression of proteins podoplanin, THY1 membrane glycoprotein and cadherin-11, but lacking CD34, is threefold expanded in patients with RA relative to patients with osteoarthritis. These fibroblasts localize to the perivascular zone in inflamed synovium, secrete proinflammatory cytokines, are proliferative, and have an in vitro phenotype characteristic of invasive cells. Our strategy may be used as a template to identify pathogenic stromal cellular subsets in other complex diseases.

Synovial fibroblasts are thought to be central mediators of joint destruction in rheumatoid arthritis (RA). Here the authors use single-cell transcriptomics and flow cytometry to identify synovial fibroblast subsets that are expanded and display distinct tissue distribution and function in patients with RA.

Autocrine Loop Involving IL-6 Family Member LIF, LIF Receptor, and STAT4 Drives Sustained Fibroblast Production of Inflammatory Mediators

Fibroblasts are major contributors to and regulators of inflammation and dominant producers of interleukin-6 (IL-6) in inflammatory diseases like rheumatoid arthritis. Yet, compared to leukocytes, the regulation of inflammatory pathways in fibroblasts is largely unknown. Here, we report that analyses of genes coordinately upregulated with IL-6 pointed to STAT4 and leukemia inhibitory factor (LIF) as potentially linked. Gene silencing revealed that STAT4 was required for IL-6 transcription. STAT4 was recruited to the IL-6 promoter after fibroblast activation, and LIF receptor (LIFR) and STAT4 formed a molecular complex that, together with JAK1 and TYK2 kinases, controlled STAT4 activation. Importantly, a positive feedback loop involving autocrine LIF, LIFR, and STAT4 drove sustained IL-6 transcription. Besides IL-6, this autorine loop also drove the production of other key inflammatory factors including IL-8, granulocyte-colony stimulating factor (G-CSF), IL-33, IL-11, IL-1α, and IL-1β. These findings define the transcriptional regulation of fibroblast-mediated inflammation as distinct from leukocytes.

Stromal cell cadherin-11 regulates adipose tissue inflammation and diabetes

M2 macrophages, innate lymphoid type 2 cells (ILC2s), eosinophils, Tregs, and invariant NK T cells (iNKT cells) all help to control adipose tissue inflammation, while M1 macrophages, TNF, and other inflammatory cytokines drive inflammation and insulin resistance in obesity. Stromal cells regulate leukocyte responses in lymph nodes, but the role of stromal cells in adipose tissue inflammation is unknown. PDGFRα+ stromal cells are major producers of IL-33 in adipose tissue. Here, we show that mesenchymal cadherin-11 modulates stromal fibroblast function. Cadherin-11-deficient mice displayed increased stromal production of IL-33, with concomitant enhancements in ILC2s and M2 macrophages that helped control adipose tissue inflammation. Higher expression levels of IL-33 in cadherin-11-deficient mice mediated ILC2 activation, resulting in higher IL-13 expression levels and M2 macrophage expansion in adipose tissue. Consistent with reduced adipose tissue inflammation, cadherin-11-deficient mice were protected from obesity-induced glucose intolerance and adipose tissue fibrosis. Importantly, anti-cadherin-11 mAb blockade similarly improved inflammation and glycemic control in obese WT mice. These results suggest that stromal fibroblasts expressing cadherin-11 regulate adipose tissue inflammation and thus highlight cadherin-11 as a potential therapeutic target for the management of obesity.

Direct suppression of autoaggressive CD8+ T cells with CD80/86 blockade in CD8+ T cell-mediated polymyositis models of mice

OBJECTIVES

CD80/86 blockade to inhibit CD28 costimulation suppressed alloreactive human and murine CD4+ T cells but not alloreactive CD8+ T cells. In contrast, CD28 costimulation augments CD8+ T cell-mediated cell lysis in antigen-nonspecific stimulation. The present study was conducted to discern whether the CD80/86 blockade exerts therapeutic effects on CD8+ T cell-mediated polymyositis (PM) models of mice and whether the effects could be attributable to direct suppression of autoantigen-specific CD8+ T cells.

METHODS

C protein-induced myositis (CIM) was induced in mice with intradermal injection of C protein fragments. C protein peptide-induced myositis (CPIM), in which autoaggressive CD8+ T cells are activated without CD4+ T cell help, was induced in mice with intravenous injection of dendritic cells (DCs) loaded with CD8+ T cell-epitope peptides derived from the C protein fragment. The immunised mice were treated with CTLA4-Ig or anti-CD80 and anti-CD86 antibodies (anti-CD80/86 Abs). The muscles were evaluated histologically 21 days after the C protein immunisation or 7 days after the DC injection.

RESULTS

CIM was suppressed in the mice treated with CTLA4-Ig or anti-CD80/86 Abs administered prophylactically from the day of immunisation and therapeutically after the disease onset. CPIM was suppressed when CTLA4-Ig was administered concurrently with the DC injection.

CONCLUSIONS

The CD80/86 blockade was effective in PM models of mice. Amelioration of CPIM indicates direct suppression of CD8+ T cells by the CD80/86 blockade. CTLA4-Ig should be a potential therapeutic agent of PM and other CD8+T cell-mediated diseases by suppressing both autoantigen-specific CD4+ and CD8+ T cells.

Hemophagocytic Syndrome Complicated with Dermatomyositis Controlled Successfully with Infliximab and Conventional Therapies

A 57-year-old woman was admitted to our hospital because of a high fever, anemia, and hyperferritinemia. Since a bone marrow examination revealed hemophagocytosis, she was diagnosed with hemophagocytic syndrome (HPS). During treatment of HPS, a heliotrope rash and Gottron's sign appeared with elevated levels of serum aldolase. She also developed heart failure. She was diagnosed with dermatomyositis (DM) and associated myocarditis. Although the administration of glucocorticoids, calcineurin inhibitors, intravenous immunoglobulins, and etoposide ameliorated the clinical findings of DM and cytopenia, the fever and hyperferritinemia remained. The addition of infliximab to glucocorticoids and tacrolimus improved the fever and hyperferritinemia and enabled a reduction in the dose of prednisolone without relapse of the diseases.

Tacrolimus successfully used to control refractory eosinophilic granulomatosis with polyangiitis complicated by invasive aspergillosis and chronic hepatitis B

While several alternatives to cyclophosphamide have been proposed for refractory eosinophilic granulomatosis with polyangiitis (EGPA), therapeutic options are limited in patients with chronic infections. We report a case of refractory EGPA complicated by invasive aspergillosis and chronic hepatitis B. Although multiple immunosuppressants, including cyclophosphamide, were not effective, tacrolimus was used successfully to control disease without exacerbating concomitant infections in the long term. Tacrolimus could be an alternative choice in the treatment of EGPA, especially when aggressive immunosuppression is unfeasible.

NFAT restricts osteochondroma formation from entheseal progenitors

Osteochondromas are common benign osteocartilaginous tumors in children and adolescents characterized by cartilage-capped bony projections on the surface of bones. These tumors often cause pain, deformity, fracture, and musculoskeletal dysfunction, and they occasionally undergo malignant transformation. The pathogenesis of osteochondromas remains poorly understood. Here, we demonstrate that nuclear factor of activated T cells c1 and c2 (NFATc1 and NFATc2) suppress osteochondromagenesis through individual and combinatorial mechanisms. In mice, conditional deletion of NFATc1 in mesenchymal limb progenitors, Scleraxis-expressing (Scx-expressing) tendoligamentous cells, or postnatally in Aggrecan-expressing cells resulted in osteochondroma formation at entheses, the insertion sites of ligaments and tendons onto bone. Combinatorial deletion of NFATc1 and NFATc2 gave rise to larger and more numerous osteochondromas in inverse proportion to gene dosage. A population of entheseal NFATc1- and Aggrecan-expressing cells was identified as the osteochondroma precursor, previously believed to be growth plate derived or perichondrium derived. Mechanistically, we show that NFATc1 restricts the proliferation and chondrogenesis of osteochondroma precursors. In contrast, NFATc2 preferentially inhibits chondrocyte hypertrophy and osteogenesis. Together, our findings identify and characterize a mechanism of osteochondroma formation and suggest that regulating NFAT activity is a new therapeutic approach for skeletal diseases characterized by defective or exaggerated osteochondral growth.

A Case Presenting with the Clinical Characteristics of Tumor Necrosis Factor (TNF) Receptor-associated Periodic Syndrome (TRAPS) without TNFRSF1A Mutations Successfully Treated with Tocilizumab

A 30-year-old woman had suffered from recurrent and self-limiting fevers since childhood. Although she had no mutations in the exons or introns of the tumor necrosis factor (TNF) receptor superfamily member 1A gene, her clinical characteristics were consistent with those of TNF receptor-associated periodic syndrome (TRAPS). She did not respond to treatment with etanercept, although tocilizumab therapy was successful, subsequently ameliorating her symptoms and preventing further inflammatory attacks. Interleukin-6 blocking therapy should be considered as a new alternative treatment in patients with TRAPS who do not respond to etanercept.

miR-31 controls osteoclast formation and bone resorption by targeting RhoA

Introduction

Increased activity of osteoclasts is responsible for bone loss and joint destruction in rheumatoid arthritis. For osteoclast development and bone resorption activity, cytoskeletal organization must be properly regulated. MicroRNAs (miRNAs) are endogenous small noncoding RNAs that suppress expression of their target genes. This study was conducted to identify crucial miRNAs to control osteoclasts.

Methods

miRNA expression in the bone marrow-derived macrophages (BMM) with or without receptor activator of nuclear factor κB ligand (RANKL) stimulation was analyzed by miRNA array. To examine the role of specific miRNAs in osteoclast formation, bone resorption activity and actin ring formation, the BMM were retrovirally transduced with miRNA antagomirs. To confirm whether the suppressive effects on osteoclastogenesis by miR-31 inhibition were mediated by targeting RhoA, osteoclast formation was analyzed in the presence of the RhoA inhibitor, exoenzyme C3.

Results

miR-31 was identified as one of the highly upregulated miRNAs during osteoclast development under RANKL stimulation. Inhibition of miR-31 by specific antagomirs suppressed the RANKL-induced formation of osteoclasts and bone resorption. Phalloidin staining of osteoclasts revealed that actin ring formation at the cell periphery was severely impaired by miR-31 inhibition, and clusters of small ringed podosomes were observed instead. In these osteoclasts, expression of RhoA, one of the miR-31 target genes, was upregulated by miR-31 inhibition in spite of the impaired osteoclastogenesis. Treatment with the RhoA inhibitor, exoenzyme C3, rescued the osteoclastogenesis impaired by miR-31 inhibition.

Conclusions

miR-31 controls cytoskeleton organization in osteoclasts for optimal bone resorption activity by regulating the expression of RhoA.

A case of relapsing polychondritis initially presenting with bronchial chondritis

A 51-year-old woman presented with one-month history of fever, productive cough, dyspnea, hoarseness and polyarthritis. Computed tomography (CT) depicted diffuse bronchotracheal stenosis, which deteriorated in exhalation. Three-dimensional CT revealed airway stenosis from the trachea to the lobar bronchi. We made a diagnosis of relapsing polychondritis (RP). Administration of high-dose glucocorticoid and oral cyclophosphamide resolved the symptoms and the bronchial stenosis. It was noteworthy that all features presented were bronchial chondritis and polyarthritis. RP should be considered when patients have polyarthritis with respiratory symptoms. The dynamic expiratory CT and three-dimensional image reconstructions are useful for detecting and following up bronchotracheal involvement.

A case of dermatomyositis with rhabdomyolysis, rescued by intravenous immunoglobulin

We describe a case of severe dermatomyositis (DM) complicated by rhabdomyolysis, acute tubular necrosis, and hemophagocytosis. The case failed to respond to corticosteroids, but showed rapid and significant improvement after the addition of intravenous immunoglobulin (IVIG). While the prognosis of DM is poor when it is complicated by rhabdomyolysis, the early administration of IVIG has the potential to be the cornerstone of its management.

Osteoblastic differentiation enhances expression of TRPV4 that is required for calcium oscillation induced by mechanical force

Mechanical stress is known to alter bone mass and the loss of force stimuli leads to reduction of bone mass. However, molecules involved in this phenomenon are incompletely understood. As mechanical force would affect signaling events in cells, we focused on a calcium channel, TRPV4 regarding its role in the effects of force stimuli on calcium in osteoblasts. TRPV4 expression levels were enhanced upon differentiation of osteoblasts in culture. We found that BMP-2 treatment enhanced TRPV4 gene expression in a dose dependent manner. BMP-2 effects on TRPV4 expression were suppressed by inhibitors for transcription and new protein synthesis. In these osteoblasts, a TRPV4-selective agonist, 4α-PDD, enhanced calcium signaling and the effects of 4α-PDD were enhanced in differentiated osteoblasts compared to the control cells. Fluid flow, as a mechanical stimulation, induced intracellular calcium oscillation in wild type osteoblasts. In contrast, TRPV4 deficiency suppressed calcium oscillation significantly even when the cells were subjected to fluid flow. These data suggest that TRPV4 is involved in the flow-induced calcium signaling in osteoblasts.

Systemic lupus erythematosus with cytophagic histiocytic panniculitis successfully treated with high-dose glucocorticoids and cyclosporine A

A 37-year-old male with systemic lupus erythematosus (SLE) presented with high fever, subcutaneous indurations, anemia, thrombocytopenia, elevated liver enzymes and hyperferritinemia. Skin biopsy revealed hemophagocytic histiocytes in the adipose tissues. The patient was diagnosed with SLE with cytophagic histiocytic panniculitis (CHP). Treatment with high-dose glucocorticoids and cyclosporine A induced remission of SLE and CHP.

CHP is generally a systemic disorder affecting subcutaneous adipose tissues with a high mortality rate. However, based on the present and previously reported cases, we believe that intensive immunosuppression can ameliorate CHP that occurs as a skin manifestation of SLE.

p16(INK4a) exerts an anti-inflammatory effect through accelerated IRAK1 degradation in macrophages

Induction of cyclin-dependent kinase (CDK) inhibitor gene p16(INK4a) into the synovial tissues suppresses rheumatoid arthritis in animal models. In vitro studies have shown that the cell-cycle inhibitor p16(INK4a) also exerts anti-inflammatory effects on rheumatoid synovial fibroblasts (RSF) in CDK activity-dependent and -independent manners. The present study was conducted to discern how p16(INK4a) modulates macrophages, which are the major source of inflammatory cytokines in inflamed synovial tissues. We found that p16(INK4a) suppresses LPS-induced production of IL-6 but not of TNF-α from macrophages. This inhibition did not depend on CDK4/6 activity and was not observed in RSF. p16(INK4a) gene transfer accelerated LPS-triggered IL-1R-associated kinase 1 (IRAK1) degradation in macrophages but not in RSF. The degradation inhibited the AP-1 pathway without affecting the NF-κB pathway. Treatment with a proteosome inhibitor prevented the acceleration of IRAK1 degradation and downregulation of the AP-1 pathway. THP-1 macrophages with forced IRAK1 expression were resistant to the p16(INK4a)-induced IL-6 suppression. Senescent macrophages with physiological expression of p16(INK4a) upregulated IL-6 production when p16(INK4a) was targeted by specific small interfering RNA. These findings indicate that p16(INK4a) promotes ubiquitin-dependent IRAK1 degradation, impairs AP-1 activation, and suppresses IL-6 production. Thus, p16(INK4a) senescence gene upregulation inhibits inflammatory cytokine production in macrophages in a different way than in RSF.

[Role of microRNA in rheumatoid arthritis]

MicroRNAs (miRNAs) are endogenous non-coding small RNAs of approximately 22 nucleotides in length. miRNAs repress expression of target genes at the posttranscription level. Biological relevance of miRNAs have been investigated in physiological and pathological conditions, revealing their involvement in fine tuning of the biological events, such as cell proliferation, differentiation and cell death. In 2008, miR-146a and miR-155 were reported to be involved in the pathology of rheumatoid arthritis. Subsequently, expression and function of other miRNAs in rheumatoid arthritis have been reported. These reports suggest that miRNAs could be novel candidates for the therapeutic target or biomarker of rheumatoid arthritis. Further investigations are required to identify, characterize and modulate the key miRNA in the pathology of rheumatoid arthritis.

Type VI collagen deficiency induces osteopenia with distortion of osteoblastic cell morphology

Bone consists of type I collagen as a major protein with minor various matrix proteins. Type VI collagen is one of bone matrix proteins but its function is not known. We therefore examined the effects of type VI collagen deficiency on bone. 3D-μCT analysis revealed that type VI collagen deficiency reduced cancellous bone mass. Cortical bone mass was not affected. Type VI collagen deficiency distorted the shape of osteoblasts both in the cancellous bone and in the cambium layer of periosteal region. Furthermore, type VI collagen deficiency disorganized collagen arrangement. These data indicate that type VI collagen contributes to maintain bone mass.

[Control of bone remodeling by nervous system. Nervous system and bone]

The relationship between bone and nervous system has been considered based on clinical observations such as Reflex Sympathetic Dystrophy (RSD) or ectopic bone formation associated with spinal cord injury. Sympathtic nervous tone has been reported to control both bone formation and bone resorption. Unloading induces bone loss due to an increase in bone resorption and decrease in bone formation. Both of these two arms are shown to be influenced by sympathetic tone. In addition, cannabinoid receptor has been observed to be involved in regulation of bone mass. Psychiatric diseases such as depression has also been suggested to linked to the alteration in the levels of bone mass. These observations together point to importance of the relationship between bone mass and nervous system.

Etanercept-induced necrotizing crescentic glomerulonephritis in two patients with rheumatoid arthritis

We present two patients with rheumatoid arthritis (RA) who developed necrotizing crescentic glomerulonephritis (NCGN) during etanercept therapy. Both patients developed proteinuria and hematuria, and one progressed to renal failure. Renal biopsy revealed NCGN. In both patients, nephritis improved following discontinuation of etanercept and administration of prednisolone. Physicians should be aware of etanercept-induced GN in patients with RA on anti-tumor necrosis factor therapy.

Osteoclast-specific Dicer gene deficiency suppresses osteoclastic bone resorption

Osteoclasts are unique cells that resorb bone, and are involved in not only bone remodeling but also pathological bone loss such as osteoporosis and rheumatoid arthritis. The regulation of osteoclasts is based on a number of molecules but full details of these molecules have not yet been understood. MicroRNAs are produced by Dicer cleavage an emerging regulatory system for cell and tissue function. Here, we examine the effects of Dicer deficiency in osteoclasts on osteoclastic activity and bone mass in vivo. We specifically knocked out Dicer in osteoclasts by crossing Dicer flox mice with cathepsin K-Cre knock-in mice. Dicer deficiency in osteoclasts decreased the number of osteoclasts (N.Oc/BS) and osteoclast surface (Oc.S/BS) in vivo. Intrinsically, Dicer deficiency in osteoclasts suppressed the levels of TRAP positive multinucleated cell development in culture and also reduced NFATc1 and TRAP gene expression. MicroRNA analysis indicated that expression of miR-155 was suppressed by RANKL treatment in Dicer deficient cells. Dicer deficiency in osteoclasts suppressed osteoblastic activity in vivo including mineral apposition rate (MAR) and bone formation rate (BFR) and also suppressed expression of genes encoding type I collagen, osteocalcin, Runx2, and Efnb2 in vivo. Dicer deficiency in osteoclasts increased the levels of bone mass indicating that the Dicer deficiency-induced osteoclastic suppression was dominant over Dicer deficiency-induced osteoblastic suppression. On the other hand, conditional Dicer deletion in osteoblasts by using 2.3 kb type I collagen-Cre did not affect bone mass. These results indicate that Dicer in osteoclasts controls activity of bone resorption in vivo.

Combinatory effects of androgen receptor deficiency and hind limb unloading on bone

Male sex hormones play a critical role in regulation of bone metabolism. In male mice lacking androgen receptor (AR), osteopenia and high turnover state in bone remodeling have been reported. However, androgen receptor's role in disuse-induced osteopenia is not known. Therefore, we examined the effects of AR deficiency on unloading-induced bone loss. Wild type or androgen receptor deficient mice (ARKO) were subjected to hind limb unloading (HU) or normal housing (Control). The groups of mice were as follows; wild type control mice (Group WT-Cont), ARKO control mice (Group ARKO-Cont), wild type HU mice (Group WT-HU), and ARKO-HU mice (Group ARKO-HU). HU reduced cancellous bone mass in ARKO (ARKO-HU) by about 70% compared to ARKO-Cont and this reduction rate was over two-fold more than that of wild type (WT-HU) (reduction by less than 30% compared to WT-Cont). Combination of ARKO and HU (ARKO-HU) resulted in the least levels of cortical bone mass and bone mineral density among the four groups. ARKO-HU group indicated the highest levels of systemic bone resorption marker, deoxypyridinoline. Osteoclast development levels in the cultures in ARKO-HU derived bone marrow cells were the highest among the four groups. These data suggest that combination of androgen receptor deficiency and hind limb unloading results in exacerbation of disuse-induced osteopenia due to the enhanced levels of bone resorption.

Angiotensin II type 2 receptor blockade increases bone mass

Renin angiotensin system (RAS) regulates circulating blood volume and blood pressure systemically, whereas RAS also plays a role in the local milieu. Previous in vitro studies suggested that RAS may be involved in the regulation of bone cells. However, it was not known whether molecules involved in RAS are present in bone in vivo. In this study, we examined the presence of RAS components in adult bone and the effects of angiotensin II type 2 (AT2) receptor blocker on bone mass. Immunohistochemistry revealed that AT2 receptor protein was expressed in both osteoblasts and osteoclasts. In addition, renin and angiotensin II-converting enzyme were expressed in bone cells in vivo. Treatment with AT2 receptor blocker significantly enhanced the levels of bone mass, and this effect was based on the enhancement of osteoblastic activity as well as the suppression of osteoclastic activity in vivo. These results indicate that RAS components are present in adult bone and that blockade of AT2 receptor results in alteration in bone mass.

Angiotensin II type 2 receptor blockade increases bone mass

Renin angiotensin system (RAS) regulates circulating blood volume and blood pressure systemically, whereas RAS also plays a role in the local milieu. Previous in vitro studies suggested that RAS may be involved in the regulation of bone cells. However, it was not known whether molecules involved in RAS are present in bone in vivo. In this study, we examined the presence of RAS components in adult bone and the effects of angiotensin II type 2 (AT2) receptor blocker on bone mass. Immunohistochemistry revealed that AT2 receptor protein was expressed in both osteoblasts and osteoclasts. In addition, renin and angiotensin II-converting enzyme were expressed in bone cells in vivo. Treatment with AT2 receptor blocker significantly enhanced the levels of bone mass, and this effect was based on the enhancement of osteoblastic activity as well as the suppression of osteoclastic activity in vivo. These results indicate that RAS components are present in adult bone and that blockade of AT2 receptor results in alteration in bone mass.

Pneumatosis cystoides intestinalis following lupus enteritis and peritonitis

We describe a case of systemic lupus erythematosus (SLE) with enteritis and peritonitis who later developed pneumatosis cystoides intestinalis (PCI). A 35-year-old woman with SLE relapsed with enteritis and peritonitis. Prednisolone (PSL) effectively improved her symptoms. However, 6 weeks later, she developed PCI. Tapering of PSL, administration of intravenous cyclophosphamide, prokinetic agents and antibiotics, bowel rest with intravenous hypernutrition therapy and hyperbaric oxygen therapy successfully improved PCI. Although PCI is a rare complication of SLE, the present case suggests that lupus enteritis could be a risk factor for PCI, and that high-dose PSL could cause additional insult to PCI.

Leflunomide-related acute interstitial pneumonia in two patients with rheumatoid arthritis: autopsy findings with a mosaic pattern of acute and organizing diffuse alveolar damage

We describe two cases of leflunomide-related interstitial pneumonia (IP). A 75-year-old woman with rheumatoid arthritis (RA) developed rapidly progressing IP 45 days after institution of leflunomide. She died of respiratory failure, and an autopsy revealed a mixed pattern of acute and organizing diffuse alveolar damage. A 69-year-old woman with RA also developed acute IP 3 months after institution of leflunomide. Methylprednisolone pulse therapy and cholestyramine ameliorated her IP. The implication of leflunomide in the pathogenesis of IP was suggested.

[Clinical evaluation for radiotherapy of metastatic brain tumors in lung cancer: prognostic analyses relevant to QOL]

From 1986 through 1992, 144 patients with metastatic brain tumors of lung cancer were treated with X-ray irradiation to whole brain or a comparatively wide field of the brain. To identify the subset of patients indicated for boost therapy like a stereotactic radiotherapy, we have analyzed the treatment results concerning both survival and performance status (PS). Median survival time of the patients in good PS (0-2) was 6.7 months, which was significantly better than 2.3 months in poor PS (3-4). Complete tumor-resectability, age, steroid therapy and condition within two months after the beginning of brain irradiation, seemed to be important prognostic indicators correlated with PS by both univariate and multivariates analyses.

[Pharmacokinetic and clinical studies on cefmenoxime in neonates and infants]

Pharmacokinetic and clinical studies on cefmenoxime (CMX) in neonates and infants were conducted. 1. CMX 20 mg/kg was administered by intravenous bolus injection to 6 neonates (with ages 2 to 20 days) and 5 infants (with ages 36 to 107 days) and its serum concentration and urinary excretion rates were determined. In the neonates, serum concentrations of CMX after intravenous administration reached peak levels of 48.2 to 90.7 micrograms/ml (mean 70.4 +/- 14.3 micrograms/ml) in 1/4 hour, then declined with half-lives of 1.27 to 5.19 hours (mean 2.28 +/- 1.56 hours), and were 3.6 to 16.9 micrograms/ml (mean 8.3 +/- 6.0 micrograms/ml) at 6 hours. In the infants, serum concentrations at 1/4 hour were 67.5 to 111.0 micrograms/ml (mean 95.5 +/- 18.0 micrograms/ml); half-lives were 0.64 to 0.94 hour (mean 0.81 +/- 0.13 hour); and the serum concentrations at 6 hours were 0.2 to 1.1 micrograms/ml (mean 0.7 +/- 0.4 micrograms/ml). Mean peak serum concentrations in the neonates tended to be lower than those in the infants, but higher than those in children. Regarding the age differences of serum concentrations due to age in the neonates, their peak levels tended to be lower in younger ones. Half-lives were shorter in older subjects and, in early infancy, approached values observed in children. Urinary recovery rates in the first 6 hours after intravenous administration ranged from 43.6 to 87.5% (mean 61.6 +/- 14.6%) in the neonates and from 52.1 to 90.8% (mean 78.0 +/- 15.1%) in the infants. Thus, recovery rates were high even in younger subjects and tended to be higher in older subjects. 2. CMX was administered to 27 neonates and 4 infants to investigate its clinical effect, bacteriological effect and side effects. Clinical efficacy ratings of the drug in 19 neonate cases that could be evaluated (1 with purulent meningitis, 2 with suspected septicemia, 1 with acute bronchitis, 12 with acute pneumonia, 1 with impetigo, 1 with periumbilical abscess and 1 with acute pyelonephritis) were "excellent" in 14 cases, "good" in 4, and "poor" in 1. The efficacy rate covering "excellent" and "good" was 94.7%. In 4 infants (2 with acute pneumonia, 1 with periumbilical abscess and 1 with acute pyelonephritis), "excellent" was obtained in 2 cases and "good" in 2 cases. Thus, all the cases showed "good" or higher ratings. Bacteriologically, 1 strain of Staphylococcus aureus and 3 strains of Escherichia coli in neonates were eradicated while, in infants, 1 strain of S. aureus persisted but 1 of E. coli was eradicated.(ABSTRACT TRUNCATED AT 400 WORDS)