Oncostatin M-driven macrophage-fibroblast circuits as a drug target in autoimmune arthritis.

BACKGROUND: Recent single-cell RNA sequencing (scRNA-seq) analysis revealed the functional heterogeneity and pathogenic cell subsets in immune cells, synovial fibroblasts and bone cells in rheumatoid arthritis (RA). JAK inhibitors which ameliorate joint inflammation and bone destruction in RA, suppress the activation of various types of cells in vitro. However, the key cellular and molecular mechanisms underlying the potent clinical effects of JAK inhibitors on RA remain to be determined. Our aim is to identify a therapeutic target for JAK inhibitors in vivo. METHODS: We performed scRNA-seq analysis of the synovium of collagen-induced arthritis (CIA) mice treated with or without a JAK inhibitor, followed by a computational analysis to identify the drug target cells and signaling pathways. We utilized integrated human RA scRNA-seq datasets and genetically modified mice administered with the JAK inhibitor for the confirmation of our findings. RESULTS: scRNA-seq analysis revealed that oncostatin M (OSM) driven macrophage-fibroblast interaction is highly activated under arthritic conditions. OSM derived from macrophages, acts on OSM receptor (OSMR)-expressing synovial fibroblasts, activating both inflammatory and tissue-destructive subsets. Inflammatory synovial fibroblasts stimulate macrophages, mainly through IL-6, to exacerbate inflammation. Tissue-destructive synovial fibroblasts promote osteoclast differentiation by producing RANKL to accelerate bone destruction. scRNA-seq analysis also revealed that OSM-signaling in synovial fibroblasts is the main signaling pathway targeted by JAK inhibitors in vivo. Mice specifically lacking OSMR in synovial fibroblasts (Osmr∆Fibro) displayed ameliorated inflammation and joint destruction in arthritis. The JAK inhibitor was effective on the arthritis of the control mice while it had no effect on the arthritis of Osmr∆Fibro mice. CONCLUSIONS: OSM functions as one of the key cytokines mediating pathogenic macrophage-fibroblast interaction. OSM-signaling in synovial fibroblasts is one of the main signaling pathways targeted by JAK inhibitors in vivo. The critical role of fibroblast-OSM signaling in autoimmune arthritis was shown by a combination of mice specifically deficient for OSMR in synovial fibroblasts and administration of the JAK inhibitor. Thus, the OSM-driven synovial macrophage-fibroblast circuit is proven to be a key driver of autoimmune arthritis, serving as a crucial drug target in vivo.

Effect of JAK inhibitors on the three forms of bone damage in autoimmune arthritis: joint erosion, periarticular osteopenia, and systemic bone loss.

BACKGROUND: The types of bone damage in rheumatoid arthritis (RA) include joint erosion, periarticular osteoporosis, and systemic osteoporosis. Janus kinase (JAK) inhibitors ameliorate inflammation and joint erosion in RA, but their effect on the three types of bone loss have not been reportedly explored in depth. We aimed to clarify how JAK inhibitors influence the various types of bone loss in arthritis by modulating osteoclastic bone resorption and/or osteoblastic bone formation. METHODS: Collagen-induced arthritis (CIA) mice were treated with a JAK inhibitor after the onset of arthritis. Micro-computed tomography (µCT) and histological analyses (bone morphometric analyses) on the erosive calcaneocuboid joint, periarticular bone (distal femur or proximal tibia), and vertebrae were performed. The effect of four different JAK inhibitors on osteoclastogenesis under various conditions was examined in vitro. RESULTS: The JAK inhibitor ameliorated joint erosion, periarticular osteopenia and systemic bone loss. It reduced the osteoclast number in all the three types of bone damage. The JAK inhibitor enhanced osteoblastic bone formation in the calcaneus distal to inflammatory synovium in the calcaneocuboid joints, periarticular region of the tibia and vertebrae, but not the inflamed calcaneocuboid joint. All the JAK inhibitors suppressed osteoclastogenesis in vitro to a similar extent in the presence of osteoblastic cells. Most of the JAK inhibitors abrogated the suppressive effect of Th1 cells on osteoclastogenesis by inhibiting IFN-γ signaling in osteoclast precursor cells, while a JAK inhibitor did not affect this effect due to less ability to inhibit IFN-γ signaling. CONCLUSIONS: The JAK inhibitor suppressed joint erosion mainly by inhibiting osteoclastogenesis, while it ameliorated periarticular osteopenia and systemic bone loss by both inhibiting osteoclastogenesis and promoting osteoblastogenesis. These results indicate that the effect of JAK inhibitors on osteoclastogenesis and osteoblastogenesis depends on the bone damage type and the affected bone area. In vitro studies suggest that while JAK inhibitors inhibit osteoclastic bone resorption, their effects on osteoclastogenesis in inflammatory environments vary depending on the cytokine milieu, JAK selectivity and cytokine signaling specificity. The findings reported here should contribute to the strategic use of antirheumatic drugs against structural damages in RA.

Angioleiomyoma mimicking a swollen bursa on first metatarsophalangeal joint accompanying with hallux valgus deformity.

We present a case of a patient who underwent a modified scarf osteotomy and tumour excision based on a preoperative diagnosis of hallux valgus deformity and accompanying bursitis. Subsequent histopathological examination revealed that the tumour was an angioleiomyoma. While tumours around the first metatarsophalangeal (MTP) joint are typically associated with gouty nodules, infections, or swollen bursa (bursitis) in patients with hallux valgus deformity, the occurrence of soft tissue tumours in this area is rare. Moreover, angioleiomyoma is an even rarer form of soft tissue tumour and is seldom suspected prior to resection. To our knowledge, there have been no reports of angioleiomyoma arising in the first MTP joint. However, it is important to consider the possibility of an atypical tumour in cases where soft tissue masses are present, even in patients with hallux valgus deformity, and to perform at least imaging tests such as ultrasound and magnetic resonance imaging before surgery. This prospect should always be kept in mind.

New Insights into the Role of Synovial Fibroblasts Leading to Joint Destruction in Rheumatoid Arthritis.

Rheumatoid arthritis (RA), one of the most common autoimmune diseases, is characterized by multiple-joint synovitis with subsequent destruction of bone and cartilage. The excessive autoimmune responses cause an imbalance in bone metabolism, promoting bone resorption and inhibiting bone formation. Preliminary studies have revealed that receptor activator of NF-κB ligand (RANKL)-mediated osteoclast induction is an important component of bone destruction in RA. Synovial fibroblasts are the crucial producers of RANKL in the RA synovium; novel analytical techniques, primarily, single-cell RNA sequencing, have confirmed that synovial fibroblasts include heterogeneous subsets of both pro-inflammatory and tissue-destructive cell types. The heterogeneity of immune cells in the RA synovium and the interaction of synovial fibroblasts with immune cells have recently received considerable attention. The current review focused on the latest findings regarding the crosstalk between synovial fibroblasts and immune cells, and the pivotal role played by synovial fibroblasts in joint destruction in RA.

Elevated expression of transforming acidic coiled-coil-containing protein 3 (TACC3) reflects aggressiveness of primary central nervous system lymphomas.

Transforming acidic coiled-coil-containing protein 3 (TACC3) plays an important role in centrosome/microtubule dynamics. Deregulation of centrosomes/microtubules causes mitotic spindle defects, leading to tumorigenesis. However, the correlation between TACC3 and primary central nervous system lymphomas (PCNSLs) is unknown. The present study investigated the association between the immunohistochemical expression of TACC3, p53, and Ki-67, and the clinical factors in 40 PCNSLs. We evaluated the staining of TACC3 based on the histoscore (H-score) that contains a semiquantitative evaluation of both the intensity of staining, and the percentage of positive cells. Expression level of each component was classified as low or high according to the median H-score value. Patients with PCNSLs were divided into groups depending on TACC3 expression levels (no expression and low expression, 18; high expression, 22). Disease-free survival and overall survival of patients with high TACC3 expression were significantly shorter (p < 0.01 and p < 0.05, respectively). These results suggest that elevated expression of TACC3 could reflects aggressiveness of primary central nervous system lymphomas.

A case of acute diffuse large B cell lymphoma in an anti-human T-cell leukaemia virus type 1-positive rheumatoid arthritis patient treated with methotrexate, who died.

A 70-year-old woman was hospitalised due to jaundice and fever. She was diagnosed with rheumatoid arthritis (RA) at 54 years of age. Treatment with methotrexate (MTX) was successful, and her RA was in remission. Five weeks before the hospitalisation, she was diagnosed with optic neuritis due to a decline in the visual acuity of the right eye. She was treated with methylprednisolone pulse therapy, followed by prednisolone (PSL), before the hospitalisation, which were not effective. Blood tests showed increased C-reactive protein (CRP) levels, liver injury, and thrombocytopenia. Abdominal echo revealed numerous enlarged lymph nodes in the hepatic portal region. Malignant lymphoma was suspected due to high serum levels of soluble interleukin-2 receptor. None of the treatments were effective, and she died on the fifth hospital day. Diffuse large B cell lymphoma was diagnosed during the autopsy, which showed infiltration of CD20-positive atypical lymphocytes in almost all organs. Since she was taking MTX, she was diagnosed with immunosuppressive drug-associated lymphoproliferative disease (LPD). Anti-human T-cell leukaemia virus type 1 (HTLV-1) antibody was detected in her serum after her death; however, adult T cell leukaemia/lymphoma was not observed. LPD develops during the treatment of RA with disease modifying anti-rheumatic drugs; however, a rapid clinical course leading to death is rarely observed. Previous reports suggest that T cell dysregulation observed in HTLV-1 may contribute towards the development of B cell lymphoma. We have discussed the possible roles of HTLV-1 in LPD development in this case.

TACC3 expression as a prognostic factor in aggressive types of adult T-cell leukemia/lymphoma patients.

INTRODUCTION: Adult T-cell leukemia/lymphoma (ATLL) is a malignant peripheral T-cell neoplasm associated with human T-cell leukemia virus type-1 (HTLV-1). The acute and lymphoma subtypes are regarded as aggressive ATLLs, and the overall survival (OS) of patients remains poor. Transforming acidic coiled-coil-containing protein 3 (TACC3) regulates microtubules, which are associated with cancer-related proteins overexpressed in various cancers. Such a relationship has not been reported in hematopoietic tumors, including ATLL. METHODS: We examined tissue microarrays of histological samples from 92 cases of aggressive ATLL and assessed clinical features, including TACC3 protein expression levels. RESULTS: Compared with TACC3-low, TACC3-high ATLL patients were significantly older (P < .001), with a tendency toward pleomorphic variant over other morphological classifications (P = .019). TACC3-high patients (median survival time [MST] 10.6 months, confidence interval [CI] [6.27-15.6]) had poorer OS compared to TACC3-low patients (MST 20 months, CI [9.43-38.5]) (P = .0168). Moreover, multivariate analysis on TACC3 expression levels suggests that TACC3-high is an independent significant prognostic factor (HR, 1.700; 95% CI, 1.037-2.753; P = .0355). CONCLUSION: Certain drugs that inhibit TACC3-overexpressing neoplastic cells are used clinically. Further studies might highlight a key role for TACC3 in the oncogenesis and progression of ATLL.

Deep learning shows the capability of high-level computer-aided diagnosis in malignant lymphoma.

A pathological evaluation is one of the most important methods for the diagnosis of malignant lymphoma. A standardized diagnosis is occasionally difficult to achieve even by experienced hematopathologists. Therefore, established procedures including a computer-aided diagnosis are desired. This study aims to classify histopathological images of malignant lymphomas through deep learning, which is a computer algorithm and type of artificial intelligence (AI) technology. We prepared hematoxylin and eosin (H&E) slides of a lesion area from 388 sections, namely, 259 with diffuse large B-cell lymphoma, 89 with follicular lymphoma, and 40 with reactive lymphoid hyperplasia, and created whole slide images (WSIs) using a whole slide system. WSI was annotated in the lesion area by experienced hematopathologists. Image patches were cropped from the WSI to train and evaluate the classifiers. Image patches at magnifications of ×5, ×20, and ×40 were randomly divided into a test set and a training and evaluation set. The classifier was assessed using the test set through a cross-validation after training. The classifier achieved the highest levels of accuracy of 94.0%, 93.0%, and 92.0% for image patches with magnifications of ×5, ×20, and ×40, respectively, in comparison to diffuse large B-cell lymphoma, follicular lymphoma, and reactive lymphoid hyperplasia. Comparing the diagnostic accuracies between the proposed classifier and seven pathologists, including experienced hematopathologists, using the test set made up of image patches with magnifications of ×5, ×20, and ×40, the best accuracy demonstrated by the classifier was 97.0%, whereas the average accuracy achieved by the pathologists using WSIs was 76.0%, with the highest accuracy reaching 83.3%. In conclusion, the neural classifier can outperform pathologists in a morphological evaluation. These results suggest that the AI system can potentially support the diagnosis of malignant lymphoma.

Clinicopathological and immunohistochemical analysis of autoimmune regulator expression in patients with osteosarcoma.

Autoimmune regulator (AIRE) is a transcription factor that is expressed in medullary thymic epithelial cells. It plays an essential role in central tolerance by eliminating self-reactive T cells. Recently, extrathymic AIRE-expressing cells have been revealed, which are associated with peripheral tolerance. Moreover, AIRE expression has been demonstrated in skin tumors and breast cancer. However, the expression of AIRE in osteosarcoma is unknown. We used immunohistochemistry to investigate AIRE expression in biopsy samples from 43 patients with conventional osteosarcoma and statistically analyzed the association between AIRE expression and clinicopathological characteristics. High AIRE expression was detected in 25 patients (58.1%), and significantly associated with the presence of lung metastasis (P = 0.014) and an increased number of forkhead box P3-positive tumor-infiltrating lymphocytes (regulatory T cells) (P = 0.014). The overall survival rate for all osteosarcoma patients with high AIRE expression was significantly shorter than that for those with low AIRE expression (P = 0.046). In a subgroup analysis of American Joint Committee on Cancer stage II patients who underwent complete surgical resection and conventional chemotherapy, the overall survival and metastasis-free survival rates were significantly shorter for patients with high AIRE expression than for those with low AIRE expression (P = 0.019 and P < 0.01, respectively). High AIRE expression was confirmed to be an independent poor prognostic factor for both overall survival (hazard ratio: 3.841, P = 0.038) and metastasis-free survival (hazard ratio: 4.348, P = 0.022) in the multivariate analysis. The evaluation of AIRE expression may be useful for stratifying osteosarcoma patients for more effective clinical follow-up.

Elevated Expression of Transforming Acidic Coiled-Coil Containing Protein 3 (TACC3) Is Associated With a Poor Prognosis in Osteosarcoma.

BACKGROUND: Transforming acidic coiled-coil containing protein 3 (TACC3) is expressed during the mitotic phase of nuclear division and regulates microtubules. Recently, high TACC3 expression in tumor cells of various cancers including soft tissue sarcoma has been reported. However, its role in osteosarcoma remains unknown. Because we have few prognostic markers for survival in osteosarcoma, we wanted to investigate the potential role of TACC3 in human osteosarcoma and determine if it is associated with survival. QUESTIONS/PURPOSES: (1) Is there a relationship between TACC3 expression and clinicopathologic characteristics such as sex, age (< 20 or ≥ 20 years), histologic type (osteoblastic or others), tumor location (femur or others), American Joint Committee on Cancer staging system (AJCC stage IIA or IIB), tumor necrosis percentage after chemotherapy (< 90% or ≥ 90%), p53 expression (low or high), and Ki-67 expression (low or high)? (2) Is TACC3 expression associated with event-free and overall survival in patients with osteosarcoma? METHODS: Forty-six conventional patients with osteosarcoma were treated at our institution from 1989 to 2013. Patients were excluded because of unresectable primary site (two patients) and no chemotherapy (two patients). Patients with metastasis at the initial visit (five patients), without pretreatment biopsy samples (two patients), or clinical charts (two patients) were also excluded. The left 33 patients who received neoadjuvant and adjuvant chemotherapy, which consisted of cisplatin/doxorubicin/methotrexate or cisplatin/doxorubicin/methotrexate/ifosfamide, and completed surgical resection with histologic wide tumor margins. Primary tumor samples before chemotherapy were used in this study. We investigated TACC3 expression using immunohistochemical staining and statistically analyzed the TACC3 expression, clinicopathologic characteristics, and event-free and overall survival in patients with osteosarcoma. RESULTS: High TACC3 expression was observed in 19 of 33 osteosarcoma specimens (58%), and this was associated with larger tumor size (ie, AJCC stage IIB in this study; p = 0.002), higher p53 expression (p = 0.007), and higher Ki-67 expression (p = 0.002). The estimated metastasis-free survival at 5 years was 21% (95% confidence interval [CI], 7%-41%) in patients with high TACC3 expression and 79% (95% CI, 47%-93%) in patients with low TACC3 expression (p < 0.001), and the estimated overall survival at 5 years was 34% (95% CI, 13%-56%) in patients with high TACC3 expression and 86% (95% CI, 54%-96%) in patients with low TACC3 expression (p < 0.001). Furthermore, high TACC3 expression was an independent poor prognostic factor for metastasis-free survival with a hazard ratio of 3.89 (95% CI, 1.07-19.78; p = 0.039) as well as overall survival with 4.41 (95% CI, 1.01-32.97; p = 0.049). CONCLUSIONS: High TACC3 expression was associated with aggressive clinicopathologic features and unfavorable prognosis in these patients with osteosarcoma. Our preliminary results suggest that further analysis about mutation or an inactive form of TACC3 would be useful to understand the mechanism of abnormal TACC3 expression in patients with osteosarcoma. If these findings are substantiated in larger studies, TACC3 might be useful for predicting survival and a potential therapeutic target for osteosarcoma. LEVEL OF EVIDENCE: Level III, therapeutic study.

Clinicopathological value of programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1) expression in synovium of patients with rheumatoid arthritis.

The etiology of rheumatoid arthritis (RA) is thought to involve dysfunction of the programmed cell death 1/programmed cell death ligand 1 (PD-1/PD-L1) pathway; PD-1 negatively regulates autoimmunity by interacting with its ligand, PD-L1. We therefore investigated PD-1/PD-L1 expression in synovial tissue of patients with RA. We immunohistochemically stained synovial specimens from 51 patients with RA and assessed the association between PD-1/PD-L1 expression and rheumatoid factor (RF), the total count of infiltrating T cells, C-reactive protein (CRP), and Krenn's synovitis score. PD-1 expression on infiltrating lymphocytes was detected in 34/51 RA cases (66.7%), while PD-1 expression was very mildly correlated only with the number of total infiltrating T cells (R2 = 0.1011, P = 0.0230). On the other hand, PD-L1 expression on synovial lining cells was observed in 37/51 RA cases (72.5%). Furthermore, a higher PD-L1 expression was significantly associated with RF positive state (P = 0.0454), and the correlations between PD-L1 expression and the number of infiltrating T cells (R2 = 0.5571, P < 0.0001), CRP (R2 = 0.4060, P < 0.0001), and Krenn's synovitis score (R2 = 0.7785, P < 0.0001) were confirmed. PD-1 was expressed on infiltrating lymphocytes, while PD-L1 was expressed on synovial lining cells; the expression of PD-L1 on synovial lining cells was significantly correlated with the active state of the disease. These data suggest that PD-1/PD-L1 pathway may have an important role in the pathogenesis of RA.

Clinicopathological analysis of immunohistochemical expression of retinoic acid-related orphan receptor-γt in peripheral T-cell lymphoma, not otherwise specified.

Peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) is cytologically and phenotypically heterogeneous. Retinoic acid-related orphan receptor-γt (RORγt) is a transcription factor that regulates the differentiation of naïve CD4+ helper T cells to Th17 cells. In the present study, we immunohistochemically confirmed the expression of RORγt in PTCL-NOS. Pathological and clinical investigations were performed for 170 cases of PTCL-NOS. RORγt-positive cases accounted for 17.6% (30/170) of the total cases, and they showed a significantly higher frequency of CD8 positivity (P = .033), lower counts of white blood cells (P = .030) and neutrophils (P = .039) in the peripheral blood, higher levels of hypergammaglobulinemia (P = .031), a higher frequency of a complete response (P = .009), and a tendency for a lower International Prognostic Index (P = .061) and better overall survival (P = .0806). These results suggest that RORγt-positive PTCL-NOS could be a subpopulation of PTCL-NOS. Further research associated with this genomic abnormality at the transcriptional level is needed to confirm the results of this study.

Clinicopathological and prognostic value of transforming acidic coiled-coil-containing protein 3 (TACC3) expression in soft tissue sarcomas.

Transforming acidic coiled-coil-containing protein 3 (TACC3), a microtubule regulator, is associated with various cancers. However, the relationship between TACC3 and soft tissue sarcomas (STS) remains unclear. We investigated the expression of TACC3 in 136 STS patient samples using immunohistochemical (IHC) staining, and the statistical associations between TACC3 expression and clinicopathological characteristics were evaluated. Additionally, the expression levels of the tumor suppressor p53 and of the cell proliferation marker Ki-67 were also assessed by IHC. High TACC3 expression was detected in 94/136 of STS cases (69.1%), and significantly correlated with higher grade according to the French Fédération Nationale des Centres de Lutte Contre le Cancer system (P<0.0001), poorer tumor differentiation (P<0.0001), increased mitotic counts (P<0.0001), advanced stage per American Joint Committee on Cancer guidelines (P<0.0001), higher p53 expression (P = 0.0487), higher Ki-67 expression (P<0.0001), and undergoing postoperative therapy (P = 0.0001). Disease-free survival (DFS) and overall survival (OS) of patients with high TACC3 expression were significantly shorter (P<0.0001 and P<0.0001, respectively). On multivariate analyses, high TACC3 expression was an independent negative prognostic factor for both DFS and OS (hazard ratio [HR]: 3.074; P = 0.0235 and HR: 8.521; P = 0.0415, respectively). Our results suggest that TACC3 is an independent prognostic factor and may be a novel therapeutic target for the treatment of STS.

A case of rheumatoid arthritis improved from Steinbrocker classification class IV to class II after multi-joint surgery.

We report the case of a patient with rheumatoid arthritis (RA) who showed a reduction in disease severity (from class IV to class II) after multi-joint surgery. The patient was a 61-year-old man with a history of RA, type-2 diabetes, chronic obstructive pulmonary disease, and nephrotic syndrome. He had been undergoing treatment for RA for the past 10 years, but his condition could not be appropriately controlled. In addition to generalized edema, marked destruction of the left elbow joint and knees was observed, and he was unable to move in bed (Steinbrocker classification: stage IV, class IV). In March 2009, he developed suppurative arthritis of the left elbow (methicillin-sensitive Staphylococcus aureus [MSSA] infection) and was referred to our institution, where the infection subsided after cleaning of the wound and administration of antibiotics. In March 2010, he underwent artificial joint replacement arthroplasty of the left elbow, followed by replacement arthroplasty of the right knee in July that year and of the left knee in November. As of December 2011, the patient showed no signs of inflammatory reactions and was able to walk using crutches (Steinbrocker classification: stage IV, class II). Recent advancements in pharmacotherapy have made it possible to control the advancement of joint destruction in RA. However, in this patient, because of the advanced stage of joint destruction, surgical methods were required to aid the patient in recovering his ability to walk.