Impact of Bone Mineral Density and Bone Structural Properties on Postmenopausal Women With Rheumatoid Arthritis in Japan: A Cross-Sectional Study

Introduction There has been no study on bone structural properties in postmenopausal women with rheumatoid arthritis (RA) in Japan. This study investigated bone mineral density (BMD) and bone structural properties in Japanese postmenopausal women with RA. Methods The study had a cross-sectional design and included 119 postmenopausal women aged 50-80 years with RA symptoms for more than five years. BMD, trabecular bone score (TBS), and results of hip structure analysis (HSA) were measured on dual-energy X-ray absorptiometry scans. The control group consisted of 288 women aged 50-80 years without RA. The RA group and control group using bisphosphonates were compared after propensity score matching for age, body mass index, and fracture history. Women in the RA group were also compared according to the use of glucocorticoids (GCs). Results After the propensity matching score, there were no other significant differences in BMD, TBS, and HSA parameters between the RA group and the control group. In the RA group, the TBS was lower in patients on GCs than those not on GCs (1.272 vs 1.313, p=0.008). There were no other significant differences in BMD and HSA parameters between patients in the RA group according to the use of GCs. Conclusion Although there were no differences in BMD, the TBS was lower in patients on GCs than those not on GCs in the RA group. It is thus important for physicians who administer GCs to treat patients with RA to be aware of not only BMD but also TBS.

Histopathological Confirmation of Axonal Sprouting in Regenerative Peripheral Nerve Interface

Symptomatic neuroma represents a debilitating complication after major limb amputation. The regenerative peripheral nerve interface (RPNI) has emerged as a reproducible and practical surgery aimed at mitigating the formation of painful neuroma. Although previous animal studies revealed axonal sprouting, elongation, and synaptogenesis of proximal nerve stump within the muscle graft in RPNI, there is a lack of reports confirming these physiological reactions at the histopathological level in human samples. This report presents a case of below-knee amputation with RPNI due to foot gangrene resulting from polyarteritis nodosa. Subsequently, an above-knee amputation was necessitated due to the exacerbation of polyarteritis nodosa, providing the opportunity for histopathological examination of the RPNI site. The examination revealed sprouting, elongation, and existence of neuromuscular junction of the tibial nerve within the grafted muscle. To the best of our knowledge, this is the first report demonstrating axonal sprouting, elongation, and possibility of synaptogenesis of the nerve stump within the grafted muscle in a human sample.

Synovial Tissue Heterogeneity in Japanese Patients With Rheumatoid Arthritis Elucidated Using a Cell-Type Deconvolution Approach

OBJECTIVE

Recent advances in single-cell RNA sequencing technology have improved our understanding of the immunological landscape of rheumatoid arthritis (RA). We aimed to stratify the synovium from East Asian patients with RA by immune cell compositions and gain insight into the inflammatory drivers of each synovial phenotype.

METHODS

Synovial tissues were obtained from East Asian patients in Japan with RA (n = 41) undergoing articular surgery. The cellular composition was quantified by a deconvolution approach using a public single-cell-based reference. Inflammatory pathway activity was calculated by gene set variation analysis, and chromatin accessibility was evaluated using assay of transposase accessible chromatin-sequencing.

RESULTS

We stratified RA synovium into three distinct subtypes based on the hierarchical clustering of cellular composition data. One subtype was characterized by abundant HLA-DRAhigh synovial fibroblasts, autoimmune-associated B cells, GZMK+ GZMB+ CD8+ T cells, interleukin (IL)1-β+ monocytes, and plasmablasts. In addition, tumor necrosis factor (TNF)-α, interferons (IFNs), and IL-6 signaling were highly activated in this subtype, and the expression of various chemokines was significantly enhanced. Moreover, we found an open chromatin region overlapping with RA risk locus rs9405192 near the IRF4 gene, suggesting the genetic background influences the development of this inflammatory synovial state. The other two subtypes were characterized by increased IFNs and IL-6 signaling, and expression of molecules associated with degeneration, respectively.

CONCLUSION

This study adds insights into the synovial heterogeneity in East Asian patients and shows a promising link with predominant inflammatory signals. Evaluating the site of inflammation has the potential to lead to appropriate drug selection that matches the individual pathology.

Evolution of genetic architecture and gene regulation in biphenyl/PCB-degrading bacteria

A variety of bacteria in the environment can utilize xenobiotic compounds as a source of carbon and energy. The bacterial strains degrading xenobiotics are suitable models to investigate the adaptation and evolutionary processes of bacteria because they appear to have emerged relatively soon after the release of these compounds into the natural environment. Analyses of bacterial genome sequences indicate that horizontal gene transfer (HGT) is the most important contributor to the bacterial evolution of genetic architecture. Further, host bacteria that can use energy effectively by controlling the expression of organized gene clusters involved in xenobiotic degradation will have a survival advantage in harsh xenobiotic-rich environments. In this review, we summarize the current understanding of evolutionary mechanisms operative in bacteria, with a focus on biphenyl/PCB-degrading bacteria. We then discuss metagenomic approaches that are useful for such investigation.

A-910823, a squalene-based emulsion adjuvant, induces T follicular helper cells and humoral immune responses via α-tocopherol component

Background

Adjuvants are chemical or biological materials that enhance the efficacy of vaccines. A-910823 is a squalene-based emulsion adjuvant used for S-268019-b, a novel vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that is currently in clinical development. Published evidence has demonstrated that A-910823 can enhance the induction of neutralizing antibodies against SARS-CoV-2 in humans and animal models. However, the characteristics and mechanisms of the immune responses induced by A-910823 are not yet known.

Methods and Results

To characterize A-910823, we compared the adaptive immune response profile enhanced by A-910823 with that of other adjuvants (AddaVax, QS21, aluminum salt-based adjuvants, and empty lipid nanoparticle [eLNP]) in a murine model. Compared with other adjuvants, A-910823 enhanced humoral immune responses to an equal or greater extent following potent T follicular helper (Tfh) and germinal center B (GCB) cell induction, without inducing a strong systemic inflammatory cytokine response. Furthermore, S-268019-b containing A-910823 adjuvant produced similar results even when given as a booster dose following primary administration of a lipid nanoparticle-encapsulated messenger RNA (mRNA-LNP) vaccine. Preparation of modified A-910823 adjuvants to identify which components of A-910823 play a role in driving the adjuvant effect and detailed evaluation of the immunological characteristics induced by each adjuvant showed that the induction of humoral immunity and Tfh and GCB cell induction in A-910823 were dependent on α-tocopherol. Finally, we revealed that the recruitment of inflammatory cells to the draining lymph nodes and induction of serum cytokines and chemokines by A-910823 were also dependent on the α-tocopherol component.

Conclusions

This study demonstrates that the novel adjuvant A-910823 is capable of robust Tfh cell induction and humoral immune responses, even when given as a booster dose. The findings also emphasize that α-tocopherol drives the potent Tfh-inducing adjuvant function of A-910823. Overall, our data provide key information that may inform the future production of improved adjuvants.

Diversity and Evolution of Integrative and Conjugative Elements Involved in Bacterial Aromatic Compound Degradation and Their Utility in Environmental Remediation

Integrative and conjugative elements (ICEs) are mobile DNA molecules that can be transferred through excision, conjugation, and integration into chromosomes. They contribute to the horizontal transfer of genomic islands across bacterial species. ICEs carrying genes encoding aromatic compound degradation pathways are of interest because of their contribution to environmental remediation. Recent advances in DNA sequencing technology have increased the number of newly discovered ICEs in bacterial genomes and have enabled comparative analysis of their evolution. The two different families of ICEs carry various aromatic compound degradation pathway genes. ICEclc and its related ICEs contain a number of members with diverse catabolic capabilities. In addition, the Tn4371 family, which includes ICEs that carry the chlorinated biphenyl catabolic pathway, has been identified. It is apparent that they underwent evolution through the acquisition, deletion, or exchange of modules to adapt to an environmental niche. ICEs have the property of both stability and mobility in the chromosome. Perspectives on the use of ICEs in environmental remediation are also discussed.

Extension Contracture Stiff Knee in Haemophilia: Surgical Timing and Procedure for Total Knee Arthroplasty

INTRODUCTION

Total knee arthroplasty (TKA) for a stiff knee of patients with hemophilia (PWH) represents a challenge for orthopaedic surgeons for the difficulties of exposing the knee and high complication rate compared to a flexible knee.

AIM

To optimize the surgical exposure in primary TKA for PWH, and to propose a threshold angle of extension contracture in treating haemophilic knee joints, retrospectively.

METHODS

67 primary TKAs for PWH (mean age, 48 years) were performed, and incisional approaches to joint were standard (58 cases) and V-Y quadricepsplasty (V-Y) (9 cases). The decision of surgical approach was decided intraoperatively by two surgeons. Pre and post knee angles were evaluated in each group. Variables in the V-Y group were evaluated using univariate logistic regression analysis and receiver operating characteristic (ROC) curve analysis.

RESULTS

Univariate logistic regression analysis demonstrated that preoperative range of motion (ROM) and flexion were significantly associated with V-Y. Threshold values of preoperative flexion and ROM resulting in V-Y using ROC analysis were 45°and 35°.

CONCLUSIONS

Primary TKA for PWH using a standard approach may be performed before the stage preoperative flexion <45° and ROM <35°.

Transcription factor Hhex negatively regulates osteoclast differentiation by controlling cyclin‐dependent kinase inhibitors

We investigated the role of hematopoietically expressed homeobox protein (Hhex) in osteoclast development. Trimethylation of lysine 27 of histone H3 at the cis‐regulatory element of Hhex was maintained and that of lysine 4 was reduced during receptor activator of nuclear factor κB ligand (RANKL)‐induced osteoclastogenesis, which was associated with a reduction of Hhex expression. Overexpression of Hhex in bone marrow–derived macrophages inhibited, whereas Hhex suppression promoted, RANKL‐induced osteoclastogenesis in vitro. Conditional deletion of Hhex in osteoclast‐lineage cells promoted osteoclastogenesis and reduced cancellous bone volume in mice, confirming the negative regulatory role of Hhex in osteoclast differentiation. Expression of cyclin‐dependent kinase inhibitors such as Cdkn2a and Cdkn1b in osteoclast precursors was negatively regulated by Hhex, and Hhex deletion increased the ratio of cells at the G1 phase of the cell cycle. In conclusion, Hhex is an inhibitor of osteoclast differentiation that is regulated in an epigenetic manner and regulates the cell cycle of osteoclast precursors and the skeletal homeostasis. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Clinical Outcomes After First Metatarsophalangeal Joint Arthrodesis by Flat Cut Joint Preparation With Individual Adjustment for Sagittal Alignment

Sagittal misalignment is a major cause of patient dissatisfaction and re-operation after first metatarsophalangeal (MTP) joint arthrodesis. The stereotypical application of the fixed angle would be undesirable, especially in cases of flat or cavus foot. We retrospectively reviewed 31 cases (27 patients) in which first MTP joint arthrodesis was performed using the flat cut joint preparation technique with reference to the plantar clearance beneath the pulp of the toe while simulating weightbearing by pushing a board against the sole. The most common underlying cause of surgery was rheumatoid arthritis (22 cases [71%]). Clinical outcomes were evaluated by the Japanese of Surgery of the Foot (JSSF) hallux scale and the self-administered foot evaluation questionnaire (SAFE-Q). Twenty-three cases were also examined by pedobarography to evaluate postoperative walking plantar pressure. At the most recent follow-up of a mean 19.6 months, the toe-to-floor distance of the hallux in static standing posture was a mean of 2.5 mm (range, 0-10 mm). All but 1 foot (97%) achieved bone union. There were no complications or revisions due to misalignment of the fused MTP joint. JSSF hallux scales improved significantly from 47 preoperatively to 82 postoperatively. All subscale scores except general health and well-being in the SAFE-Q improved significantly at final follow-up versus preoperative period. Plantar pressure under the hallux was correlated with the toe-to-floor distance but not radiographic parameter. In conclusion, first MTP joint arthrodesis achieved good clinical outcomes when using toe-to-floor distance and Kirschner wire template for flat cut joint preparation.

Accuracy of an artificial intelligence-based model for estimating leftover liquid food in hospitals: validation study (Preprint)

Background

An accurate evaluation of the nutritional status of malnourished hospitalized patients at a higher risk of complications, such as frailty or disability, is crucial. Visual methods of estimating food intake are popular for evaluating the nutritional status in clinical environments. However, from the perspective of accurate measurement, such methods are unreliable.

Objective

The accuracy of estimating leftover liquid food in hospitals using an artificial intelligence (AI)–based model was compared to that of visual estimation.

Methods

The accuracy of the AI-based model (AI estimation) was compared to that of the visual estimation method for thin rice gruel as staple food and fermented milk and peach juice as side dishes. A total of 576 images of liquid food (432 images of thin rice gruel, 72 of fermented milk, and 72 of peach juice) were used. The mean absolute error, root mean squared error, and coefficient of determination (R²) were used as metrics for determining the accuracy of the evaluation process. Welch t test and the confusion matrix were used to examine the difference of mean absolute error between AI and visual estimation.

Results

The mean absolute errors obtained through the AI estimation approach were 0.63 for fermented milk, 0.25 for peach juice, and 0.85 for the total. These were significantly smaller than those obtained using the visual estimation approach, which were 1.40 (P<.001) for fermented milk, 0.90 (P<.001) for peach juice, and 1.03 (P=.009) for the total. By contrast, the mean absolute error for thin rice gruel obtained using the AI estimation method (0.99) did not differ significantly from that obtained using visual estimation (0.99). The confusion matrix for thin rice gruel showed variation in the distribution of errors, indicating that the errors in the AI estimation were biased toward the case of many leftovers. The mean squared error for all liquid foods tended to be smaller for the AI estimation than for the visual estimation. Additionally, the coefficient of determination (R²) for fermented milk and peach juice tended to be larger for the AI estimation than for the visual estimation, and the R² value for the total was equal in terms of accuracy between the AI and visual estimations.

Conclusions

The AI estimation approach achieved a smaller mean absolute error and root mean squared error and a larger coefficient of determination (R²) than the visual estimation approach for the side dishes. Additionally, the AI estimation approach achieved a smaller mean absolute error and root mean squared error compared to the visual estimation method, and the coefficient of determination (R²) was similar to that of the visual estimation method for the total. AI estimation measures liquid food intake in hospitals more precisely than visual estimation, but its accuracy in estimating staple food leftovers requires improvement.

An Electrical Stimulation Culture System for Daily Maintenance-Free Muscle Tissue Production

Low-labor production of tissue-engineered muscles (TEMs) is one of the key technologies to realize the practical use of muscle-actuated devices. This study developed and then demonstrated the daily maintenance-free culture system equipped with both electrical stimulation and medium replacement functions. To avoid ethical issues, immortal myoblast cells C2C12 were used. The system consisting of gel culture molds, a medium replacement unit, and an electrical stimulation unit could produce 12 TEMs at one time. The contractile forces of the TEMs were measured with a newly developed microforce measurement system. Even the TEMs cultured without electrical stimulation generated forces of almost 2 mN and were shortened by 10% in tetanic contractions. Regarding the contractile forces, electrical stimulation by a single pulse at 1 Hz was most effective, and the contractile forces in tetanus were over 2.5 mN. On the other hand, continuous pulses decreased the contractile forces of TEMs. HE-stained cross-sections showed that myoblast cells proliferated and fused into myotubes mainly in the peripheral regions, and fewer cells existed in the internal region. This must be due to insufficient supplies of oxygen and nutrients inside the TEMs. By increasing the supplies, one TEM might be able to generate a force up to around 10 mN. The tetanic forces of the TEMs produced by the system were strong enough to actuate microstructures like previously reported crawling robots. This daily maintenance-free culture system which could stably produce TEMs strong enough to be utilized for microrobots should contribute to the advancement of biohybrid devices.

Identification of the Gene Responsible for Lignin-Derived Low-Molecular-Weight Compound Catabolism in Pseudomonas sp. Strain LLC-1

Pseudomonas sp. strain LLC-1 (NBRC 111237) is capable of degrading lignin-derived low-molecular-weight compounds (LLCs). The genes responsible for the catabolism of LLCs were characterized in this study using whole-genome sequencing. Despite the close phylogenetic relationship with Pseudomonas putida, strain LLC-1 lacked the genes usually found in the P. putida genome, which included fer, encoding an enzyme for ferulic acid catabolism, and vdh encoding an NAD⁺-dependent aldehyde dehydrogenase specific for its catabolic intermediate, vanillin. Cloning and expression of the 8.5 kb locus adjacent to the van operon involved in vanillic acid catabolism revealed the bzf gene cluster, which is involved in benzoylformic acid catabolism. One of the structural genes identified, bzfC, expresses the enzyme (BzfC) having the ability to transform vanillin and syringaldehyde to corresponding acids, indicating that BzfC is a multifunctional enzyme that initiates oxidization of LLCs in strain LLC-1. Benzoylformic acid is a catabolic intermediate of (R,S)-mandelic acid in P. putida. Strain LLC-1 did not possess the genes for mandelic acid racemization and oxidation, suggesting that the function of benzoylformic acid catabolic enzymes is different from that in P. putida. Genome-wide characterization identified the bzf gene responsible for benzoylformate and vanillin catabolism in strain LLC-1, exhibiting a unique mode of dissimilation for biomass-derived aromatic compounds by this strain.

Parsing multiomics landscape of activated synovial fibroblasts highlights drug targets linked to genetic risk of rheumatoid arthritis

OBJECTIVES

Synovial fibroblasts (SFs) are one of the major components of the inflamed synovium in rheumatoid arthritis (RA). We aimed to gain insight into the pathogenic mechanisms of SFs through elucidating the genetic contribution to molecular regulatory networks under inflammatory condition.

METHODS

SFs from RA and osteoarthritis (OA) patients (n=30 each) were stimulated with eight different cytokines (interferon (IFN)-α, IFN-γ, tumour necrosis factor-α, interleukin (IL)-1β, IL-6/sIL-6R, IL-17, transforming growth factor-β1, IL-18) or a combination of all 8 (8-mix). Peripheral blood mononuclear cells were fractioned into five immune cell subsets (CD4⁺ T cells, CD8⁺ T cells, B cells, natural killer (NK) cells, monocytes). Integrative analyses including mRNA expression, histone modifications (H3K27ac, H3K4me1, H3K4me3), three-dimensional (3D) genome architecture and genetic variations of single nucleotide polymorphisms (SNPs) were performed.

RESULTS

Unstimulated RASFs differed markedly from OASFs in the transcriptome and epigenome. Meanwhile, most of the responses to stimulations were shared between the diseases. Activated SFs expressed pathogenic genes, including CD40 whose induction by IFN-γ was significantly affected by an RA risk SNP (rs6074022). On chromatin remodelling in activated SFs, RA risk loci were enriched in clusters of enhancers (super-enhancers; SEs) induced by synergistic proinflammatory cytokines. An RA risk SNP (rs28411362), located in an SE under synergistically acting cytokines, formed 3D contact with the promoter of metal-regulatory transcription factor-1 (MTF1) gene, whose binding motif showed significant enrichment in stimulation specific-SEs. Consistently, inhibition of MTF1 suppressed cytokine and chemokine production from SFs and ameliorated mice model of arthritis.

CONCLUSIONS

Our findings established the dynamic landscape of activated SFs and yielded potential therapeutic targets associated with genetic risk of RA.

Predictability of postoperative recurrence on hepatocellular carcinoma through data mining method

Hepatocellular carcinoma (HCC) is a highly lethal tumor and the majority of postoperative patients experience recurrence. In the present study, we focus on the predictability of postoperative recurrence on HCC through the data mining method. In total, 323 patients with HCC who underwent hepatic resection were included in the present study, 156 of whom suffered from cancer recurrence. Clinicopathological data including prognosis were analyzed using the data mining method for the predictability of postoperative recurrence on HCC. The resulting alternating decision tree (ADT) was described using data mining method. This tree was validated using a 10-fold cross validation process. The average and standard deviation of the accuracy, sensitivity, and specificity were 69.0±8.2, 59.7±14.5 and 77.7±10.2%, respectively. The identified postoperative recurrence factors were age, viral hepatitis, stage, GOT and T-cholesterol. Data mining method could identify the factors associated at different levels of significance with postoperative recurrence of HCC. These factors could help to predict the postoperative recurrence of HCC.

Sustained anti-osteoporotic action of risedronate compared to anti-RANKL antibody following discontinuation in ovariectomized mice

Bisphosphonates and the anti-receptor activator of nuclear factor-kappa B ligand (RANKL) antibody denosumab are effective anti-resorptive drugs commonly prescribed for osteoporosis. Both drugs may, however, have intolerable side effects; so, it is critical to examine their residual efficacy such as maintenance of bone mass following cessation. Therefore, we compared the changes in bone histology following discontinuation of the aminobisphosphonate risedronate and anti-RANKL antibody in ovariectomized (OVX) mice. Twelve-week-old female C57BL/6 N mice were OVX or sham operated. Four weeks after surgery, mice were treated with vehicle, a single injection of anti-RANKL antibody (5 mg/kg), or risedronate (5 μg/kg/day, s.c.) for 4 weeks (the treatment period), followed by vehicle treatment for an additional 4 weeks (discontinuation period). The lumbar spine and proximal tibia were evaluated by micro-computed tomography. In addition, the lumbar spine, proximal tibia, and the femoral shaft were examined by bone histomorphometry. After 4 weeks of discontinuation, OVX mice initially treated with the anti-RANKL antibody exhibited a trend of bone loss associated with increased turnover in both trabecular and cortical bones, although the difference was not significant. By contrast, OVX mice treated with risedronate exhibited maintained or even increased bone mass and suppressed bone turnover. Patients discontinuing denosumab should be carefully monitored for recurrent osteoporosis symptoms, and a replacement drug should be considered.

•

Bone mass and suppression of turnover were maintained after stopping bisphophonates.

•

Bone turnover was rapidly increased after discontinuation of anti-RANKL antibody.

•

Periosteal bone formation was maintained after administration of antiresorptive drugs.

The role of medical informatics in the management of medical information

With progress in information and communication technology, medical information has been converted to digital formats and stored and managed using computer systems. The construction, management, and operation of medical information systems and regional medical liaison systems are the main components of the clinical tasks of medical informatics departments. Research using medical information accumulated in these systems is also a task for medical informatics department. Recently, medical real-world data (RWD) accumulated in medical information systems has become a focus not only for primary use but also for secondary uses of medical information. However, there are many problems, such as standardization, collection, cleaning, and analysis of them. The internet of things and artificial intelligence are also being applied in the collection and analysis of RWD and in resolving the above problems. Using these new technologies, progress in medical care and clinical research is about to enter a new era. J. Med. Invest. 67 : 27-29, February, 2020.

Association between fall history and performance-based physical function and postural sway in patients with rheumatoid arthritis

OBJECTIVES

Patients with rheumatoid arthritis (RA) are at increased risk of falling; therefore, fall prevision and prevention are critical. The present study aimed to evaluate the ability of physical performance assessments to discriminate between RA patients with and without a history of falling.

METHODS

Fifty patients with RA were divided into two groups according to the presence or absence of a history of falls within the previous 1 year. Physical performance was assessed using the short physical performance battery (SPPB), which consists of the timed standing balance, gait speed, and chair stand tests. Standing balance was also assessed as postural sway using a force platform in several positions including standing with both feet together, semitandem, and tandem. Backgrounds, SPPB, and postural sway were compared between the two groups.

RESULTS

Fourteen patients (28%) reported one or more falls within the previous year. There were no significant intergroup differences in baseline characteristics or SPPB score. The group with a history of falls had significantly longer measured time for the 5-repetition chair stand test and significantly longer postural sway in the semitandem position. The discriminate analysis revealed that 5-repetition chair stand test or its combination with postural sway in the semitandem position significantly discriminated between fallers and non-fallers.

CONCLUSION

Numerical evaluation of the chair stand test and postural sway in the semitandem position seems more appropriate than SPPB for assessing the fall risk of patients with RA.

CTLA4-Ig Directly Inhibits Osteoclastogenesis by Interfering With Intracellular Calcium Oscillations in Bone Marrow Macrophages

CTLA4-Ig (cytotoxic T-lymphocyte antigen 4-immunoglobulin; Abatacept) is a biologic drug for rheumatoid arthritis. CTLA4 binds to the CD80/86 complex of antigen-presenting cells and blocks the activation of T cells. Although previous reports showed that CTLA4-Ig directly inhibited osteoclast differentiation, the whole inhibitory mechanism of CTLA4-Ig for osteoclast differentiation is unclear. Bone marrow macrophages (BMMs) from WT mice were cultured with M-CSF and RANKL with or without the recombinant mouse chimera CTLA4-Ig. Intracellular calcium oscillations of BMMs with RANKL were detected by staining with calcium indicator fura-2 immediately after administration of CTLA4-Ig or after one day of treatment. Calcium oscillations were analyzed using Fc receptor gamma- (FcRγ-) deficient BMMs. CTLA4-Ig inhibited osteoclast differentiation and reduced the expression of the nuclear factor of activated T cells NFATc1 in BMMs in vitro. Calcium oscillations in BMMs were suppressed by CTLA4-Ig both immediately after administration and after one day of treatment. CTLA4-Ig did not affect osteoclastogenesis and did not cause remarkable changes in calcium oscillations in FcRγ-deficient BMMs. Finally, to analyze the effect of CTLA4-Ig in vivo, we used an LPS-induced osteolysis model. CTLA4-Ig suppressed LPS-induced bone resorption in WT mice, not in FcRγ-deficient mice. In conclusion, CTLA4-Ig inhibits intracellular calcium oscillations depending on FcRγ and downregulates NFATc1 expression in BMMs. © 2019 American Society for Bone and Mineral Research.

ASP1126, a Novel Sphingosine-1-Phosphate-Selective Agonist With a Favorable Safety Profile, Prolongs Allograft Survival in Rats and Nonhuman Primates in Combination With Tacrolimus With a Broad Safety Margin for Bradycardia

Sphingosine-1-phosphate (S1P) is a biologically active sphingolipid that acts through the members of a family of 5 G protein-coupled receptors (S1P₁ to S1P₅). Among these, S1P₁ is a major regulator of lymphocyte trafficking. Fingolimod, whose active metabolite, fingolimod phosphate, acts as a nonselective S1P-receptor agonist, exerts its immunomodulatory effect, at least in part, by regulating lymphocyte trafficking via downregulation of S1P₁ expression on lymphocytes. Here, we describe the pharmacologic profile of a novel S1P₁ agonist, ASP1126. ASP1126 preferentially activated S1P₁ compared to S1P₃ in rat and human guanosine-5'-(γ-thio)-triphosphate (GTPγS) assays. Oral single administration of ASP1126 decreased the number of peripheral lymphocytes and repeated dosing showed a cumulative effect on lymphopenia in both rats and monkeys. ASP1126 prolonged allograft survival in a rat heterotopic heart transplantation model in combination with a subtherapeutic dose of tacrolimus that was independent of drug-drug interactions. In addition, in nonhuman primate (NHP) renal transplantation, pretreatment with ASP1126 reduced not only the number of naive T cells and central memory T cells but also effector memory T cells in the peripheral blood, all of which could contribute to acute graft rejection and prolonged allograft survival in combination with tacrolimus. Further, we confirmed that ASP1126 has a broad ranging safety margin with respect to its effect on lung weight in rats and bradycardia in NHPs, which were the adverse events found in clinical studies of fingolimod. ASP1126 with improved safety profile has the potential to be an adjunct therapy in combination with tacrolimus in clinical transplantation.

Cooperation of PU.1 With IRF8 and NFATc1 Defines Chromatin Landscapes During RANKL-Induced Osteoclastogenesis

Receptor activator of nuclear factor κB ligand (RANKL) induces osteoclast (OC) differentiation from bone marrow-derived macrophages (BMMs). The transcription factors nuclear factor of activated T cells 1 (NFATc1) and interferon regulatory factor (IRF) 8 play positive and negative roles, respectively, in this process. However, genomewide mapping of the active cis-regulatory elements regulating OC differentiation has not been performed, and little is known about the global landscape of OC-specific gene regulation. We used chromatin immunoprecipitation and formaldehyde-assisted isolation of regulatory elements followed by sequencing to show that PU.1 transcription factor binding motifs were overrepresented at active cis-regulatory regions in both murine BMMs and OCs, while IRF and NFAT binding motifs were selectively enriched at these regions in BMMs and OCs, respectively. We also found that RANKL induced the downregulation of Irf8 and upregulation of Nfatc1 expression, which was associated with dramatic alterations in histone modification. BMM-specific PU.1 binding sites were observed to overlap with IRF8 binding sites in BMMs, and this also occurred for OC-specific PU.1 binding sites and NFATc1 binding sites in OCs. The expression of genes with IRF8 peaks within BMM-specific PU.1 binding sites was significantly higher in BMMs than in OCs, while that of genes with NFATc1 peaks within OC-specific PU.1 binding sites was significantly higher in OCs than in BMMs. Our results suggest that PU.1 switches its transcription partner from IRF8 to NFATc1 and alters the binding regions during RANKL-induced osteoclastogenesis, which is associated with changes in epigenetic profiles and the control of cell type-specific gene expression. © 2019 American Society for Bone and Mineral Research.

Biphenyl/PCB Degrading bph Genes of Ten Bacterial Strains Isolated from Biphenyl-Contaminated Soil in Kitakyushu, Japan: Comparative and Dynamic Features as Integrative Conjugative Elements (ICEs)

We sequenced the entire genomes of ten biphenyl/PCB degrading bacterial strains (KF strains) isolated from biphenyl-contaminated soil in Kitakyushu, Japan. All the strains were Gram-negative bacteria belonging to β- and γ-proteobacteria. Out of the ten strains, nine strains carried a biphenyl catabolic bph gene cluster as integrative conjugative elements (ICEs), and they were classified into four groups based on the structural features of the bph genes. Group I (five strains) possessed bph genes that were very similar to the ones in Pseudomonasfurukawaii KF707 (formerly Pseudomonas pseudoalcaligenes KF707), which is one of the best characterized biphenyl-utilizing strains. This group of strains carried salicylate catabolic sal genes that were approximately 6-kb downstream of the bph genes. Group II (two strains) possessed bph and sal genes similar to the ones in KF707, but these strains lacked the bphX region between bphC and bphD, which is involved in the downstream catabolism of biphenyl. These bph-sal clusters in groups I and II were located on an integrative conjugative element that was larger than 110 kb, and they were named ICE_bph-sal. Our previous study demonstrated that the ICE_bph-sal of Pseudomonas putida KF715 in group II existed both in an integrated form in the chromosome (referred to as ICE_bph-salKF715 (integrated)) and in a extrachromosomal circular form (referred to as ICE_bph-sal (circular)) (previously called pKF715A, 483 kb) in the stationary culture. The ICE_bph-sal was transferred from KF715 into P. putida AC30 and P. putida KT2440 with high frequency, and it was maintained stably as an extrachromosomal circular form. The ICE_bph-salKF715 (circular) in these transconjugants was further transferred to P. putida F39/D and then integrated into the chromosome in one or two copies. Meanwhile, group III (one strain) possessed bph genes, but not sal genes. The nucleotide sequences of the bph genes in this group were less conserved compared to the genes of the strains belonging to groups I and II. Currently, there is no evidence to indicate that the bph genes in group III are carried by a mobile element. Group IV (two strains) carried bph genes as ICEs (59–61 kb) that were similar to the genes found in Tn4371 from Cupriavidus oxalacticus A5 and ICE_KKS1024677 from the Acidovorax sp. strain KKS102. Our study found that bph gene islands have integrative functions, are transferred among soil bacteria, and are diversified through modification.

Gorham-Stout Syndrome of the Shoulder Girdle Successfully Controlled by Antiresorptive Agents: A Report of 2 Cases

CASE

Gorham-Stout disease (GSD) is a rare disorder characterized by massive bone destruction. Consensus is lacking on the effective treatment strategies for GSD. This report presents 2 cases of GSD, a 47-year-old man and a 72-year-old woman, involving the shoulder girdle which were successfully controlled by antiresorptive agents including bisphosphonates and denosumab, the antireceptor activator of nuclear factor-κB ligand antibody.

CONCLUSIONS

These 2 cases suggest that antiresorptive agents targeting osteoclasts can be efficacious therapeutic options for GSD. This is the first case of GSD we are aware of which showed good response to denosumab treatment.

Guideposts for Inserting Intercuneiform Joint Arthrodesis Screws: Analysis Using Multiplanar Reconstructed Computed Tomography

Intercuneiform arthrodesis is often required for various midfoot pathologies; however, intercuneiform screw insertion is not easy due to the complicated anatomical structure of cuneiforms. This study aimed to determine the advisable screw entry point and direction using intraoperatively detectable landmarks. The computed tomography (CT) scan data of feet were reformatted using OsiriX software multiplanar reconstruction. First, based on the data of 10 CT scans of normal feet, we determined the advisable screw entry point at the upper one-third in the dorsoplantar direction and center in the anteroposterior direction on the medial aspect of the medial cuneiform and insertion direction toward the outermost point of the base of the fifth metatarsal in the axial plane and parallel to the plantar surface in the coronal plane. Second, we examined the accuracy of these newly designed guideposts in the simulation using other CT scan data of the other 27 normal feet and 12 flat feet. The simulated screw trajectory penetrated the mid three-fifths of all three cuneiforms in 97% of the normal feet and 92% of the flat feet with no cases of cortical wall violation. Levels of Evidence: Level V: Expert opinion.