Extracellular aaRSs drive autoimmune and inflammatory responses in rheumatoid arthritis via the release of cytokines and PAD4.

OBJECTIVES: Recent studies demonstrate that extracellular-released aminoacyl-tRNA synthetases (aaRSs) play unique roles in immune responses and diseases. This study aimed to understand the role of extracellular aaRSs in the pathogenesis of rheumatoid arthritis (RA). METHODS: Primary macrophages and fibroblast-like synoviocytes were cultured with aaRSs. aaRS-induced cytokine production including IL-6 and TNF-α was detected by ELISA. Transcriptomic features of aaRS-stimulated macrophages were examined using RNA-sequencing. Serum and synovial fluid (SF) aaRS levels in patients with RA were assessed using ELISA. Peptidyl arginine deiminase (PAD) 4 release from macrophages stimulated with aaRSs was detected by ELISA. Citrullination of aaRSs by themselves was examined by immunoprecipitation and western blotting. Furthermore, aaRS inhibitory peptides were used for inhibition of arthritis in two mouse RA models, collagen-induced arthritis and collagen antibody-induced arthritis. RESULTS: All 20 aaRSs functioned as alarmin; they induced pro-inflammatory cytokines through the CD14-MD2-TLR4 axis. Stimulation of macrophages with aaRSs displayed persistent innate inflammatory responses. Serum and SF levels of many aaRSs increased in patients with RA compared with control subjects. Furthermore, aaRSs released PAD4 from living macrophages, leading to their citrullination. We demonstrate that aaRS inhibitory peptides suppress cytokine production and PAD4 release by aaRSs and alleviate arthritic symptoms in a mouse RA model. CONCLUSIONS: Our findings uncovered the significant role of aaRSs as a novel alarmin in RA pathogenesis, indicating that their blocking agents are potent antirheumatic drugs.

Concomitant Treatment with Etanercept and Tacrolimus Synergistically Attenuates Arthritis Progression via Inhibition of Matrix Metalloproteinase-3 Production and Osteoclastogenesis in Human TNF-α Transgenic Mice.

In the present study, we investigated the effects and mechanisms of action of a combined treatment with etanercept, a soluble tumor necrosis factor receptor (p75) Fc fusion protein, and tacrolimus, a calcineurin inhibitor on the progression of arthritis in human tumor necrosis factor-α (TNF-α) transgenic (hTNF-Tg) mice. Single-drug treatments with etanercept and tacrolimus attenuated the clinical signs but not the radiographic changes associated with the development of arthritis in mice. On the contrary, combined treatment significantly suppressed the radiographic progression and also improved the clinical signs. The combined treatment exhibited synergistic effects of the two drugs in reducing the serum matrix metalloproteinase-3 level and the number of peripheral CD11bhigh osteoclast precursor cells. Moreover, tacrolimus inhibited the cytokine-induced osteoclast differentiation in synergy with etanercept in an in vitro assay. Interestingly, tacrolimus did not inhibit the production of antidrug antibodies (ADAs) against etanercept in the hTNF-Tg mice. This result implies that the synergistic effects of etanercept and tacrolimus are not due to secondary effects derived from the suppression of ADA production by tacrolimus but are due to their primary effects. These findings suggest that concomitant treatment with etanercept and tacrolimus may be one of preferable treatment options to control disease activities for patients with rheumatoid arthritis, especially for those with bone resorption.

SPACIA1/SAAL1 Deletion Results in a Moderate Delay in Collagen-Induced Arthritis Activity, along with mRNA Decay of Cyclin-dependent Kinase 6 Gene.

This study was performed to elucidate the molecular function of the synoviocyte proliferation-associated in collagen-induced arthritis (CIA) 1/serum amyloid A-like 1 (SPACIA1/SAAL1) in mice CIA, an animal model of rheumatoid arthritis (RA), and human RA-synovial fibroblasts (RASFs). SPACIA1/SAAL1-deficient mice were generated and used to create mouse models of CIA in mild or severe disease conditions. Cell cycle-related genes, whose expression levels were affected by SPACIA1/SAAL1 small interfering RNA (siRNA), were screened. Transcriptional and post-transcriptional effects of SPACIA1/SAAL1 siRNA on cyclin-dependent kinase (cdk) 6 gene expression were investigated in human RASFs. SPACIA1/SAAL1-deficient mice showed later onset and slower progression of CIA than wild-type mice in severe disease conditions, but not in mild conditions. Expression levels of cdk6, but not cdk4, which are D-type cyclin partners, were downregulated by SPACIA1/SAAL1 siRNA at the post-transcriptional level. The exacerbation of CIA depends on SPACIA1/SAAL1 expression, although CIA also progresses slowly in the absence of SPACIA1/SAAL1. The CDK6, expression of which is up-regulated by the SPACIA1/SAAL1 expression, might be a critical factor in the exacerbation of CIA.

Prediction of Postoperative Clinical Recovery of Drop Foot Attributable to Lumbar Degenerative Diseases, via a Bayesian Network.

BACKGROUND: Drop foot resulting from degenerative lumbar diseases can impair activities of daily living. Therefore, predictors of recovery of this symptom have been investigated using univariate or/and multivariate analyses. However, the conclusions have been somewhat controversial. Bayesian network models, which are graphic and intuitive to the clinician, may facilitate understanding of the prognosis of drop foot resulting from degenerative lumbar diseases. QUESTIONS/PURPOSES: (1) To show a layered correlation among predictors of recovery from drop foot resulting from degenerative lumbar diseases; and (2) to develop support tools for clinical decisions to treat drop foot resulting from lumbar degenerative diseases. METHODS: Between 1993 and 2013, we treated 141 patients with decompressive lumbar spine surgery who presented with drop foot attributable to degenerative diseases. Of those, 102 (72%) were included in this retrospective study because they had drop foot of recent development and had no diseases develop that affect evaluation of drop foot after surgery. Specifically, 28 (20%) patients could not be analyzed because their records were not available at a minimum of 2 years followup after surgery and 11 (8%) were lost owing to postoperative conditions that affect the muscle strength evaluation. Eight candidate variables were sex, age, herniated soft disc, duration of the neurologic injury (duration), preoperative tibialis anterior muscle strength (pretibialis anterior), leg pain, cauda equina syndrome, and number of involved levels. Manual muscle testing was used to assess the tibialis anterior muscle strength. Drop foot was defined as a tibialis anterior muscle strength score of less than 3 of 5 (5 = movement against gravity and full resistance, 4 = movement against gravity and moderate resistance, 3 = movement against gravity through full ROM, 3- = movement against gravity through partial ROM, 2 = movement with gravity eliminated through full ROM, 1 = slight contraction but no movement, and 0 = no contraction). The two outcomes of interest were postoperative tibialis anterior muscle strength (posttibialis anterior) of 3 or greater and posttibialis anterior strength of 4 or greater at 2 years after surgery. We developed two separate Bayesian network models with outcomes of interest for posttibialis anterior strength of 3 or greater and posttibialis anterior strength of 4 or greater. The two outcomes correspond to "good" and "excellent" results based on previous reports, respectively. Direct predictors are defined as variables that have the tail of the arrow connecting the outcome of interest, whereas indirect predictors are defined as variables that have the tail of the arrow connecting either direct predictors or other indirect predictors that have the tail of the arrow connecting direct predictors. Sevenfold cross validation and receiver-operating characteristic (ROC) curve analyses were performed to evaluate the accuracy and robustness of the Bayesian network models. RESULTS: Both of our Bayesian network models showed that weaker muscle power before surgery (pretibialis anterior ≤ 1) and longer duration of neurologic injury before treatment (> 30 days) were associated with a decreased likelihood of return of function by 2 years. The models for posttibialis anterior muscle strength of 3 or greater and posttibialis anterior muscle strength of 4 or greater were the same in terms of the graphs, showing that the two direct predictors were pretibialis anterior muscle strength (score ≤ 1 or ≥ 2) and duration (≤ 30 days or > 30 days). Age, herniated soft disc, and leg pain were identified as indirect predictors. We developed a decision-support tool in which the clinician can enter pretibialis anterior muscle strength and duration, and from this obtain the probability estimates of posttibialis anterior muscle strength. The probability estimates of posttibialis anterior muscle strength of 3 or greater and posttibialis anterior muscle strength of 4 or greater were 94% and 85%, respectively, in the most-favorable conditions (pretibialis anterior ≥ 2; duration ≤ 30 days) and 18% and 14%, respectively, in the least-favorable conditions (pretibialis anterior ≤ 1; duration > 30 days). On the sevenfold cross validation, the area under the ROC curve yielded means of 0.78 (95% CI, 0.68-0.87) and 0.74 (95% CI, 0.64-0.84) for posttibialis anterior muscle strength of 3 or greater and posttibialis anterior muscle strength of 4 or greater, respectively. CONCLUSIONS: The results of this study suggest that the clinician can understand intuitively the layered correlation among predictors by Bayesian network models. Based on the models, the decision-support tool successfully provided the probability estimates of posttibialis anterior muscle strength to treat drop foot attributable to lumbar degenerative diseases. These models were shown to be robust on the internal validation but should be externally validated in other populations. LEVEL OF EVIDENCE: Level III, therapeutic study.

Surgical outcomes for painless drop foot due to degenerative lumbar disorders.

STUDY DESIGN: Twenty patients presenting with painless drop foot who had undergone lumbar spine surgery for degenerative lumbar diseases were included in this retrospective study. OBJECTIVE: This study aims to investigate which causative factors and patient symptoms significantly affected surgical outcome. SUMMARY OF BACKGROUND DATA: Drop foot is a neuromuscular condition that results in dorsiflexion palsy of the ankle. Patients with drop foot often complain of leg pain. Rarely, patients experience painless drop foot due to lumbar degenerative disease. For these patients, the only purpose of surgery is to improve the palsy; this makes it difficult to determine whether surgical intervention is indicated. No studies have focused on the results of surgical treatment for painless drop foot caused by degenerative lumbar diseases. METHODS: Preoperative strength of the tibialis anterior and duration of palsy were recorded and considered with surgical outcome. RESULTS: Sixty-five percent of patients recovered from drop foot after surgery. Drop foot was caused mainly by impairment of the L5 nerve root. Patients with a longer duration of palsy had poorer results. CONCLUSIONS: Duration of palsy had the greatest effect on recovery. As the only goal of this surgery is improvement in the strength of the tibialis anterior, caution must be exercised when considering surgery for patients with longstanding palsy.

Three-dimensional and multienergy gamma-ray simultaneous imaging by using a Si/CdTe Compton camera.

PURPOSE: To develop a silicon (Si) and cadmium telluride (CdTe) imaging Compton camera for biomedical application on the basis of technologies used for astrophysical observation and to test its capacity to perform three-dimensional (3D) imaging. MATERIALS AND METHODS: All animal experiments were performed according to the Animal Care and Experimentation Committee (Gunma University, Maebashi, Japan). Flourine 18 fluorodeoxyglucose (FDG), iodine 131 ((131)I) methylnorcholestenol, and gallium 67 ((67)Ga) citrate, separately compacted into micro tubes, were inserted subcutaneously into a Wistar rat, and the distribution of the radioisotope compounds was determined with 3D imaging by using the Compton camera after the rat was sacrificed (ex vivo model). In a separate experiment, indium 111((111)In) chloride and (131)I-methylnorcholestenol were injected into a rat intravenously, and copper 64 ((64)Cu) chloride was administered into the stomach orally just before imaging. The isotope distributions were determined with 3D imaging after sacrifice by means of the list-mode-expectation-maximizing-maximum-likelihood method. RESULTS: The Si/CdTe Compton camera demonstrated its 3D multinuclear imaging capability by separating out the distributions of FDG, (131)I-methylnorcholestenol, and (67)Ga-citrate clearly in a test-tube-implanted ex vivo model. In the more physiologic model with tail vein injection prior to sacrifice, the distributions of (131)I-methylnorcholestenol and (64)Cu-chloride were demonstrated with 3D imaging, and the difference in distribution of the two isotopes was successfully imaged although the accumulation on the image of (111)In-chloride was difficult to visualize because of blurring at the low-energy region. CONCLUSION: The Si/CdTe Compton camera clearly resolved the distribution of multiple isotopes in 3D imaging and simultaneously in the ex vivo model.

Protocol for the RETHINK study: a randomised, double-blind, parallel-group, non-inferiority clinical trial comparing acetaminophen and NSAIDs for treatment of chronic pain in elderly patients with osteoarthritis of the hip and knee.

INTRODUCTION: In patients with chronic pain, oral analgesics are essential treatment options to manage pain appropriately, improve activities of daily living abilities and achieve a higher quality of life (QOL). It is desirable to select analgesics for elderly patients based on comparative data on analgesic effect and risk of adverse events; however, there are few comparative studies so far. The purpose of this study is to determine whether the efficacy and safety of acetaminophen are non-inferior to non-steroidal anti-inflammatory drugs (NSAIDs) in the treatment of chronic pain associated with osteoarthritis of the hip and knee in elderly patients. METHODS AND ANALYSIS: This study is a multicentre, randomised controlled, double-blind, parallel-group study to compare the analgesic effect and adverse events between acetaminophen or NSAIDs (loxoprofen or celecoxib). A total of 400 elderly patients with osteoarthritis of the hip and knee will be recruited from five institutions in Japan. Patients of 65 years or older with osteoarthritis-related pain will be registered and randomly assigned to acetaminophen, loxoprofen or celecoxib with 2:1:1 allocation. The primary endpoint is change in the Brief Pain Inventory (BPI) item 3 (worst pain) score from baseline to week 8. The secondary endpoints are BPI item 3 score change from baseline to week 4, health-related QOL measured by Short Form-8 Health Survey, and occurrence of adverse events including gastrointestinal disorders and abnormal liver function. Data will be analysed in accordance with a predefined statistical analysis plan. ETHICS AND DISSEMINATION: This study protocol was approved by the Kyushu University Hospital Certified Institutional Review Board for Clinical Trials on 28 January 2021 (KD2020004) and the chief executive of each participating hospital. The results of the study will be submitted to international peer-reviewed journals, and the main findings will be presented at international scientific conferences. TRIAL REGISTRATION NUMBER: jRCTs071200112.

Overexpression of SPACIA1/SAAL1, a newly identified gene that is involved in synoviocyte proliferation, accelerates the progression of synovitis in mice and humans.

OBJECTIVE: To identify novel genes associated with dysregulated proliferation of activated synovial fibroblasts, which are involved in arthritic joint destruction. METHODS: We performed transcriptome analysis to identify genes that were up-regulated in the foot joints of mice with collagen-induced arthritis (CIA). The effect of candidate genes on proliferation of synovial fibroblasts was screened using antisense oligodeoxynucleotides and small interfering RNAs (siRNAs). We characterized the expression and function of a novel gene, synoviocyte proliferation-associated in collagen-induced arthritis 1 (SPACIA1)/serum amyloid A-like 1 (SAAL1) using antibodies and siRNA and established transgenic mice to examine the effect of SPACIA1/SAAL1 overexpression in CIA. RESULTS: Human and mouse SPACIA1/SAAL1 encoded 474 amino acid proteins that shared 80% homology. SPACIA1/SAAL1 was primarily expressed in the nucleus of rheumatoid arthritis (RA) synovial fibroblasts and was highly expressed in the hyperplastic lining of inflamed synovium. In addition, its expression level in RA- or osteoarthritis (OA)-affected synovial tissue was positively correlated with the thickness of the synovial lining. Furthermore, SPACIA1/SAAL1 siRNA inhibited the proliferation of synovial fibroblasts, especially tumor necrosis factor α-induced synovial fibroblasts, by blocking entry into the S phase without inducing apoptosis. Finally, transgenic mice overexpressing SPACIA1/SAAL1 exhibited early onset and rapid progression of CIA. CONCLUSION: These results suggest that SPACIA1/SAAL1 is necessary for abnormal proliferation of synovial fibroblasts and its overexpression is associated with the progression of synovitis in mice and humans. Thus, therapy targeting SPACIA1/SAAL1 might have potential as an inhibitor of synovial proliferation in RA and/or OA.

Intraspinal epidermoid tumor of the cauda equina region: seven cases and a review of the literature.

STUDY DESIGN: Retrospective case series. OBJECTIVE: To investigate the clinical features and surgical outcomes of patients with intraspinal epidermoid tumor of the cauda equina region. SUMMARY OF BACKGROUND DATA: Intraspinal epidermoid tumor of the cauda equina region is very rare, and the majority of the existing literature of this condition comprises case reports with a few case series. METHODS: The clinical features and surgical outcomes of 7 patients (2 males, 5 females; age range, 4-66 y) with intraspinal epidermoid tumor of the cauda equina region were retrospectively studied, and a literature review was performed. All patients complained of neurologic symptoms and underwent microscope-assisted surgery. The mean duration of postoperative follow-up was 126 months (range, 52-209 mo). RESULTS: Antecedent lumbar puncture had been performed on 3 patients, and 4 cases thought to be of congenital origin without a past history of lumbar puncture had no associated anomalies, such as spina bifida or dermal sinus. Postoperatively, complications occurred in 3 patients concerning cauda equina symptom. Two patients (29%) had tumor recurrence, diagnosed 1 and 13 years after surgery, respectively. Immediately after additional surgery for tumor recurrence, both patients had severe paresis of the hemilateral foot. CONCLUSIONS: Complete removal without tear of the tumor was difficult in our case series, because the capsule of the tumor was thin and often adhered to the cauda equina nerve roots or dura mater. However, total resection of the capsule is important, because patients with epidermoid tumor are at risk for recurrence. On the other hand, aggressive resection of the capsule adhering to the neural elements can cause a high rate of neurological complications postoperatively, especially after surgery for tumor recurrence.

Risk factors for insufficient reduction after short-segment posterior fixation for thoracolumbar burst fractures: Does the interval from injury onset to surgery affect reduction of fractured vertebrae?

BACKGROUND: Many surgeons have encountered patients who could not immediately undergo surgery to treat spinal fractures because they had associated injuries and/or because a complete diagnosis was delayed. For such patients, practitioners might assume that delays could mean that the eventual reduction would be insufficient. However, no report covered risk factors for insufficient reduction of fractured vertebra including duration from injury onset to surgery. The purpose of this study is to investigate the risk factors for insufficient reduction after short-segment fixation of thoracolumbar burst fractures. METHODS: Our multicenter study included 253 patients who sustained a single thoracolumbar burst fracture and underwent short-segment fixation. We measured the local vertebral body angle (VBA) on roentgenograms, before and after surgery, and then calculated the reduction angle and reduction rate of the fractured vertebra by using the following formula: [Formula: see text] A multiple logistical regression analysis was performed to identify risk factors for insufficient reduction. The factors that we evaluated were age, gender, affected spine level, time elapsed from injury to surgery, inclusion of vertebroplasty with surgery, load-sharing score (LSS), AO classification (type A or B), preoperative VBA, and the ratio of canal compromise before surgery. RESULTS: There were 140 male and 113 female patients, with an average age of 43 years, and the mean time elapsed between injury and surgery was 3.8 days. The mean reduction angle was 12°, and the mean reduction rate was 76%. The mean LSS was 6.4 points. Multiple linear regression analysis revealed that a higher LSS, a larger preoperative VBA, a younger age, and being female disposed patients to having a larger reduction angle and reduction rate. The time elapsed from injury to surgery had no relation to the quality of fracture reduction in the acute period. CONCLUSIONS: Our findings indicate that if there is no neurologic deficit, we might not need to hurry surgical reduction of fractured vertebrae in the acute phase.

Determination of gastric atrophy with artificial intelligence compared to the assessments of the modified Kyoto and OLGA classifications.

Background and Aim: Gastric atrophy is a precancerous lesion. We aimed to clarify whether gastric atrophy determined by artificial intelligence (AI) correlates with the diagnosis made by expert endoscopists using several endoscopic classifications, the Operative Link on Gastritis Assessment (OLGA) classification based on histological findings, and genotypes associated with gastric atrophy and cancer. Methods: Two hundred seventy Helicobacter pylori-positive outpatients were enrolled. All patients' endoscopy data were retrospectively evaluated based on the Kimura-Takemoto, modified Kyoto, and OLGA classifications. The AI-trained neural network generated a continuous number between 0 and 1 for gastric atrophy. Nucleotide variance of some candidate genes was confirmed or selectively assessed for a variety of genotypes, including the COX-21195, IL-1ß 511, and mPGES-1 genotypes. Results: There were significant correlations between determinations of gastric atrophy by AI and by expert endoscopists using not only the Kimura-Takemoto classification (P < 0.001), but also the modified Kyoto classification (P = 0.046 and P < 0.001 for the two criteria). Moreover, there was a significant correlation with the OLGA classification (P = 0.009). Nucleotide variance of the COX-2, IL-1ß, and mPGES-1genes was not significantly associated with gastric atrophy determined by AI. The area under the curve values of the combinations of AI and the modified Kyoto classification (0.746) and AI and the OLGA classification (0.675) were higher than in AI alone (0.665). Conclusion: Combinations of AI and the modified Kyoto classification or of AI and the OLGA classification could be useful tools for evaluating gastric atrophy in patients with H. pylori infection as the risk of gastric cancer.

Prostaglandin EP2 receptor signalling inhibits the expression of matrix metalloproteinase 13 in human osteoarthritic chondrocytes.

OBJECTIVES: Matrix metalloproteinase (MMP) 13 is a pathogenic collagenase that causes cartilage destruction and plays a leading role in causing osteoarthritis. This study focused on 114 genes that are differentially expressed between intact and damaged osteoarthritis cartilage, in order to determine which molecules are involved in suppressing MMP-13 expression. METHODS: MMP-13 concentrations were measured in the supernatant of human osteoarthritis chondrocyte cultures transfected with small interfering RNA (siRNA) against the 114 genes. MMP-13 levels changed most dramatically in response to siRNA against prostaglandin EP2 receptor. The authors performed further measurements of MMP-13 production in osteoarthritis chondrocytes stimulated by the EP2 agonist butaprost in the presence or absence of interleukin-1ß (IL-1ß) and/or cyclooxygenase-2 (COX-2) inhibitor. They also assessed the effect of butaprost on chondrocyte viability, and investigated the involvement of the cAMP-protein kinase A (PKA) pathway on EP2 signalling using inhibitors. Cartilage-related gene expression was examined in chondrocytes treated with butaprost. The authors also investigated which E series of prostaglandin (EP) receptors are expressed in osteoarthritis cartilage. RESULTS: MMP-13 messenger RNA expression was significantly affected by two molecules, EP2 receptor and SLC14A1, a urea transporter. In IL-1ß-treated osteoarthritis chondrocytes, butaprost suppressed MMP-13 production, which was further decreased by COX-2 inhibitor. EP2 signalling downregulated MMP-13 mRNA expression via the cAMP-PKA pathway without affecting cell viability. Although EP2 signalling enhanced IL-6 expression, the expressions of several catabolic factors (MMP-1, MMP-3, MMP-13, ADAMTS5, IL-1ß and tumour necrosis factor alpha) were inhibited. EP2 receptor was the major EP receptor in osteoarthritis cartilage. CONCLUSION: The results suggest that EP2 signalling has 'anti-catabolic' effects in osteoarthritis chondrocytes.

KDR inhibitor with the intramolecular non-bonded interaction: conformation-activity relationships of novel indole-3-carboxamide derivatives.

We previously reported that compound 1, having a similar conformation to PTK787 (2) by forming a pseudo ring structure with an intramolecular non-bonded S-O interaction, exhibited a potent inhibitory activity against VEGFR2 tyrosine kinase (KDR). Applying the ideas of pseudo ring formations, we have designed three types of novel indole carboxamide derivatives 5-7 with an intramolecular hydrogen bonding or non-bonded S-O interaction. We describe the design and synthesis of 5-7, and also discuss the relationships of their KDR inhibitory activity and conformations that were stabilized by their intramolecular non-bonded interactions.

Pyridylmethylthio derivatives as VEGF inhibitors: part 2.

Optimization of compounds 5 and 6 led to the discovery of VEGF inhibitor 10g which reduced CYP inhibition. It was highly active in vitro (VEGF induced HUVEC proliferation assay) and showed efficacies in three disease models in vivo (cancer, RA, and AMD).

Pyridylmethylthio derivatives as VEGF inhibitors. Part 1.

Optimization from compound 4a, having intramolecular S-O nonbonded interaction, led to discover compounds 4m and 4n. They were highly active in vitro (VEGF induced HUVEC proliferation assay) and showed efficacies in three disease models in vivo (cancer, RA, AMD).

Effects of SA13353, a transient receptor potential vanilloid 1 agonist, on leukocyte infiltration in lipopolysaccharide-induced acute lung injury and ovalbumin-induced allergic airway inflammation.

We recently demonstrated that SA13353, a transient receptor potential vanilloid 1 (TRPV1) agonist, reduced the severity of the symptoms of kidney injury, arthritis, and encephalomyelitis in disease models. Here, we investigated the effects of orally administered SA13353 on leukocyte infiltration in lipopolysaccharide (LPS)-induced acute lung injury and ovalbumin-induced allergic airway inflammation. In LPS-induced lung injury, SA13353 attenuated neutrophil infiltration and the increase of TNF-alpha and CINC-1 levels. In allergic airway inflammation, SA13353 tended to inhibit leukocyte infiltration and attenuated the increase of IL-4 and IL-12p40. These results suggest that somatosensory TRPV1 may play an anti-inflammatory role in lung inflammation.

Role of leukotriene B4 in 5-lipoxygenase metabolite- and allergy-induced itch-associated responses in mice.

We investigated the role of leukotriene (LT) B(4) in 5-lipoxygenase metabolite- and allergy-induced itch-associated responses using SA6541, an LTA(4) hydrolase inhibitor. Itch-associated responses were induced by intradermal injection of 5-hydroperoxyeicosatetraenoic acid (HPETE), a precursor of 5-lipoxygenase metabolites, and passive cutaneous anaphylaxis in ICR mice. By screening molecules related to arachidonic acid metabolism or pruritus, SA6541 was found to be a specific inhibitor of LTA(4) hydrolase. Pharmacokinetic studies confirmed the specificity of SA6541 at an oral dose of 100 mg/kg in mice. 5-HPETE induced scratching behavior, which was inhibited by SA6541 (100 mg/kg). However, SA6541 (100 mg/kg) hardly attenuated the 5-HPETE-induced increase in vascular permeability. Moreover, SA6541 (100 mg/kg) partially attenuated scratching behavior, but did not affect the increase in vascular permeability caused by passive cutaneous anaphylaxis. On the other hand, ketotifen fumarate, a histamine H1 antagonist, strongly inhibited the scratching behavior and the increase in vascular permeability caused by passive cutaneous anaphylaxis. These results suggest that LTB(4) is an endogenous itch mediator in the skin and is involved in the pruritus response in allergic reactions.

ARG098, a novel anti-human Fas antibody, suppresses synovial hyperplasia and prevents cartilage destruction in a severe combined immunodeficient-HuRAg mouse model.

BACKGROUND: The anti-human Fas/APO-1/CD95 (Fas) mouse/human chimeric monoclonal IgM antibody ARG098 (ARG098) targets the human Fas molecule. The cytotoxic effects of ARG098 on cells isolated from RA patients, on normal cells in vitro, and on RA synovial tissue and cartilage in vivo using implanted rheumatoid tissues in an SCID mouse model (SCID-HuRAg) were investigated to examine the potential of ARG098 as a therapy for RA. METHODS: ARG098 binding to each cell was analyzed by cytometry. The effects of ARG098 on several cells were assessed by a cell viability assay in vitro. Effects on the RA synovium, lymphocytes, and cartilage were assessed in vivo using the SCID-HuRAg mouse model. RESULTS: ARG098 bound to cell surface Fas molecules, and induced apoptosis in Fas-expressing RA synoviocytes and infiltrating lymphocytes in the RA synovium in a dose-dependent manner. However, ARG098 did not affect the cell viability of peripheral blood mononuclear cells of RA patients or normal chondrocytes. ARG098 also induced apoptosis in RA synoviocytes and infiltrating lymphocytes in the RA synovium in vivo. The destruction of cartilage due to synovial invasion was inhibited by ARG098 injection in the modified SCID-HuRAg mouse model. CONCLUSIONS: ARG098 treatment suppressed RA synovial hyperplasia through the induction of apoptosis and prevented cartilage destruction in vivo. These results suggest that ARG098 might become a new therapy for RA.

Combined effects of bucillamine and etanercept on a rat type II collagen-induced arthritis model.

The combined effects of bucillamine (Buc) and etanercept (ETN) on a rat model of type II collagen (CII)-induced arthritis (CIA) after treatment onset were investigated. In the combination treatment, rats received Buc 30 mg/kg orally administered once daily from the onset of arthritis or from 4 days after the onset of arthritis and ETN 0.3 mg/kg subcutaneously administered once on the day of onset. The effects of monotherapy with Buc and ETN, respectively, and of Buc + ETN combination therapy on the resulting polyarthritis were evaluated by histopathological analyses and measurements of hindpaw volumes, serum anti-collagen antibody and immunoglobulin levels, and cytokine levels. The Buc + ETN therapeutic combination reduced hindpaw swelling, synovial proliferation, bone destruction, new bone formation, and inflammatory cell infiltration in CIA. Montherapy with Buc showed a tendency to ameliorate these symptoms, while monotherapy with ETN reduced hindpaw swelling at 4 days after administration but did not maintain treatment efficacy toward the end of the experimental period. Histopathological findings did not reveal any efficacy of the ETN therapy. ETN alone increased the serum immunoglobulin levels, while its combination with Buc reduced these levels. Similar results were obtained for serum anti-CII antibody titers. The Buc + ETN combination treatment also reduced serum interleuking (IL)-1alpha and granulocyte macrophage colony-stimulating factor and tended to reduce serum IL-1beta and IL-6 levels. These results suggest that a combination therapy of Buc and ETN may be effective for the treatment of rheumatoid arthritis (RA).

Adjacent-segment disease after L3-4 posterior lumbar interbody fusion: does L3-4 fusion have cranial adjacent-segment degeneration similar to that after L4-5 fusion?

OBJECTIVE: Posterior lumbar interbody fusion (PLIF) is a widely accepted procedure for degenerative lumbar diseases, and there have been many reports concerning adjacent-segment disease (ASD) after PLIF. In the reports of ASD in which the fusion level was limited to 1 segment, all reports describe ASD of the L3-4 segment after L4-5 PLIF. On the basis of these reports, it is thought that ASD mainly occurs at the cranial segment. However, no report has covered ASD after L3-4 PLIF. Therefore, the authors investigated ASD after L3-4 PLIF. METHODS: In conducting a retrospective case series analysis, the authors reviewed a surgical database providing details of all spine operations performed between 2006 and 2017 at a single institution. During that period, PLIF was performed to treat 632 consecutive patients with degenerative lumbar diseases. Of these patients, 71 were treated with L3-4 PLIF alone, and 67 who were monitored for at least 2 years (mean 5.8 years; follow-up rate 94%) after surgery were enrolled in this study. Radiological ASD (R-ASD), symptomatic ASD (S-ASD), and operative ASD (O-ASD) were evaluated. These types of ASD were defined as follows: R-ASD refers to radiological degeneration adjacent to the fusion segment as shown on plain radiographs; S-ASD is a symptomatic condition due to neurological deterioration at the adjacent-segment degeneration; and O-ASD refers to S-ASD requiring revision surgery. RESULTS: All patients had initial improvement of neurological symptoms after primary PLIF. R-ASD was observed in 32 (48%) of 67 patients. It occurred at the cranial segment in 12 patients and at the caudal segment in 24; R-ASD at both adjacent segments was observed in 4 patients. Thus, the occurrence of R-ASD was more significant in the caudal segment than in the cranial segment. S-ASD was observed in 10 patients (15%), occurring at the cranial segment in 3 patients and at the caudal segment in 7. O-ASD was observed in 6 patients (9%): at the cranial segment in 1 patient and at the caudal segment in 5. Thus, the rate of involvement of the caudal segment was 67% in R-ASD, 70% in S-ASD, and 83% in O-ASD. CONCLUSIONS: The incidences of R-ASD, S-ASD, and O-ASD were 48%, 15%, and 9%, respectively, after L3-4 PLIF for degenerative lumbar diseases. In contrast to ASD after L4-5 PLIF, ASD after L3-4 PLIF was more frequently observed at the caudal segment than at the cranial segment. In follow-up for patients with L3-4 PLIF, surgeons should pay attention to ASD in the caudal segment.