Distinctiveness of Femoral and Acetabular Mesenchymal Stem and Progenitor Populations in Patients with Primary and Secondary Hip Osteoarthritis Due to Developmental Dysplasia.

Primary hip osteoarthritis (pOA) develops without an apparent underlying reason, whereas secondary osteoarthritis arises due to a known cause, such as developmental dysplasia of the hips (DDH-OA). DDH-OA patients undergo total hip arthroplasty at a much younger age than pOA patients (50.58 vs. 65 years in this study). Recently, mesenchymal stem and progenitor cells (MSPCs) have been investigated for the treatment of osteoarthritis due to their immunomodulatory and regenerative potential. This study identified cells in subchondral bone expressing common MSPC markers (CD10, CD73, CD140b, CD146, CD164, CD271, GD2, PDPN) in vivo and compared the proportions of these populations in pOA vs. DDH-OA, further correlating them with clinical, demographic, and morphological characteristics. The differences in subchondral morphology and proportions of non-hematopoietic cells expressing MSPC markers were noted depending on OA type and skeletal location. Bone sclerosis was more prominent in the pOA acetabulum (Ac) in comparison to the DDH-OA Ac and in the pOA Ac compared to the pOA femoral head (Fh). Immunophenotyping indicated diagnosis-specific differences, such as a higher proportion of CD164+ cells and their subsets in DDH-OA, while pOA contained a significantly higher proportion of CD10+ and GD2+ cells and subsets, with CD271+ being marginally higher. Location-specific differences showed that CD271+ cells were more abundant in the Fh compared to the Ac in DDH-OA patients. Furthermore, immunohistochemical characterization of stromal bone-adjacent cells expressing MSPC markers (CD10, CD164, CD271, GD2) in the Ac and Fh compartments was performed. This research proved that immunophenotype profiles and morphological changes are both location- and disease-specific. Furthermore, it provided potentially effective targets for therapeutic strategies. Future research should analyze the differentiation potential of subsets identified in this study. After proper characterization, they can be selectively targeted, thus enhancing personalized medicine approaches in joint disease management.

Serum S100A12 levels in children with childhood-onset systemic lupus erythematosus, systemic juvenile arthritis, and systemic undefined recurrent fevers.

BACKGROUND: We compared serum levels of S100A12, a proinflammatory protein predominantly secreted by neutrophils, in children with newly diagnosed childhood-onset systemic lupus erythematosus (cSLE), systemic juvenile arthritis (sJIA), and systemic undefined recurrent fevers (SURFS) to examine its role as a diagnostic and discriminative marker of inflammation and to indirectly point out the importance of neutrophils and innate immunity in the pathogenesis of these diseases. MATERIALS AND METHODS: In a cross-sectional study, the serum levels of S100A12 protein of 68 children (19 with cSLE, 18 with sJIA, 7 with SURFS, and 24 controls) were determined by enzyme-linked immunosorbent assay and compared between groups and with clinical and laboratory findings. RESULTS: The median serum S100A12 levels were 469 ng/mL in the cSLE group, 6103 ng/mL in the sJIA group, 480 ng/mL in the SURFS group, and 44 ng/mL in the control group. Children with cSLE, sJIA, and SURFS had significantly higher serum S100A12 levels compared to the control group (p < 0.0001). sJIA patients had the highest levels of S100A12 in comparison to other patients (p < 0.0001), while there was no significant difference between children with cSLE and SURFS. CONCLUSION: Elevated serum SA100A12 levels in children with cSLE, sJIA, and SURFS may indicate intense neutrophil activation, which may play an important role in innate immunity in chronic inflammation in these diseases. Serum S100A12 levels could be used as a diagnostic marker of inflammation and be suitable for distinguishing sJIA and other disorders.

Reciprocal Alterations in Osteoprogenitor and Immune Cell Populations in Rheumatoid Synovia.

Rheumatoid arthritis (RA) is chronic, autoimmune joint inflammation characterized by irreversible joint destruction. Besides increased resorption, destruction is a result of decreased bone formation, due to suppressed differentiation and function of the mesenchymal lineage-derived osteoblasts in inflammatory milieu. In this study, we analyzed the cellular composition of synovial tissue from 11 RA and 10 control patients harvested during planned surgeries in order to characterize resident synovial progenitor populations. Synovial cells were released by collagenase, and labeled for flow cytometry by two antibody panels: 1. CD3-FITC, CD14-PE, 7-AAD, CD11b-PECy7, CD235a-APC, CD19-APCeF780; and 2. 7-AAD, CD105-PECy7, CD45/CD31/CD235a-APC, and CD200-APCeF780. The proportions of lymphocytes (CD3+, CD19+) and myeloid (CD11b+, CD14+) cells were higher in synovial tissue from the patients with RA than in the controls. Among non-hematopoietic (CD45-CD31-CD235a-) cells, there was a decrease in the proportion of CD200+CD105- and increase in the proportion of CD200-CD105+ cells in synovial tissue from the patients with RA in comparison to the control patients. The proportions of both populations were associated with inflammatory activity and could discriminate between the RA and the controls.

A niche-dependent myeloid transcriptome signature defines dormant myeloma cells.

The era of targeted therapies has seen significant improvements in depth of response, progression-free survival, and overall survival for patients with multiple myeloma. Despite these improvements in clinical outcome, patients inevitably relapse and require further treatment. Drug-resistant dormant myeloma cells that reside in specific niches within the skeleton are considered a basis of disease relapse but remain elusive and difficult to study. Here, we developed a method to sequence the transcriptome of individual dormant myeloma cells from the bones of tumor-bearing mice. Our analyses show that dormant myeloma cells express a distinct transcriptome signature enriched for immune genes and, unexpectedly, genes associated with myeloid cell differentiation. These genes were switched on by coculture with osteoblastic cells. Targeting AXL, a gene highly expressed by dormant cells, using small-molecule inhibitors released cells from dormancy and promoted their proliferation. Analysis of the expression of AXL and coregulated genes in human cohorts showed that healthy human controls and patients with monoclonal gammopathy of uncertain significance expressed higher levels of the dormancy signature genes than patients with multiple myeloma. Furthermore, in patients with multiple myeloma, the expression of this myeloid transcriptome signature translated into a twofold increase in overall survival, indicating that this dormancy signature may be a marker of disease progression. Thus, engagement of myeloma cells with the osteoblastic niche induces expression of a suite of myeloid genes that predicts disease progression and that comprises potential drug targets to eradicate dormant myeloma cells.

The anatomy lesson of the SARS-CoV-2 pandemic: irreplaceable tradition (cadaver work) and new didactics of digital technology.

AIM: To compare the efficacy of different components of online and contact anatomy classes as perceived by medical students. METHODS: An anonymous course evaluation survey was conducted at the end of the academic year 2019/2020. The organization of classes due to the SARS-CoV-2 pandemic provided our students with a unique opportunity to compare online and contact classes. Students' responses were analyzed according to the type of obtained data (ratio, ordinal, and categorical). RESULTS: The response rate was 95.58%. Approximately 90% of students found anatomical dissection and practical work in general to be the most important aspect of teaching, which could not be replaced by online learning. During online classes, students missed the most the interaction with other students, followed by the interaction with student teaching assistants and teaching staff. Very few students found contact lectures useful, with most students reporting that they could be replaced with recorded video lectures. In contrast, recorded video lectures were perceived as extremely helpful for studying. Regular weekly quizzes were essential during online classes as they gave students adequate feedback and guided their learning process. Students greatly benefitted from additional course materials and interactive lessons, which were made easily available via e-learning platform. CONCLUSIONS: Anatomical dissection and interaction during contact classes remain the most important aspects of teaching anatomy. However, online teaching increases learning efficiency by allowing alternative learning strategies and by substituting certain components of contact classes, thus freeing up more time for practical work.

LPS-induced inflammation desensitizes hepatocytes to Fas-induced apoptosis through Stat3 activation-The effect can be reversed by ruxolitinib.

Recent studies have established a concept of tumour necrosis factor-α (TNF-α)/Fas signalling crosstalk, highlighting TNF-α as a critical cytokine in sensitizing hepatocytes to death induced by Fas activation. However, in the exact inflammatory response, besides TNF-α, many other mediators, that might modulate apoptotic response differentially, are released. To resolve the issue, we studied the effects of lipopolysaccharide (LPS), one of the crucial inductors of inflammation in the liver, on apoptotic outcome. We show that LPS-induced inflammation diminishes the sensitivity of hepatocytes to Fas stimulus in vivo at caspase-8 level. Analysis of molecular mechanisms revealed an increased expression of various pro-inflammatory cytokines in non-parenchymal liver cells and hepatocyte-specific increase in Bcl-xL, associated with signal transducer and activator of transcription 3 (Stat3) phosphorylation. Pre-treatment with ruxolitinib, a selective Janus kinase (JAK) 1/2 inhibitor, prevented the LPS-induced Stat3 phosphorylation and restored the sensitivity of hepatocytes to Fas-mediated apoptosis. Furthermore, ruxolitinib pre-treatment diminished the LPS-induced Bcl-xL up-regulation without an inhibitory effect on LPS-induced expression of pro-inflammatory cytokines. In summary, although the reports are showing that the effects of isolated pro-inflammatory mediators, such as TNF-α or neutrophils, are pro-apoptotic, the overall effect of inflammatory milieu on hepatocytes in vivo is Stat3-dependent desensitization to Fas-mediated apoptosis.

Fas receptor induces apoptosis of synovial bone and cartilage progenitor populations and promotes bone loss in antigen-induced arthritis.

Rheumatoid arthritis (RA) is an inflammatory joint disease that eventually leads to permanent bone and cartilage destruction. Fas has already been established as the regulator of inflammation in RA, but its role in bone formation under arthritic conditions is not completely defined. The aim of this study was to assess the effect of Fas inactivation on the bone damage during murine antigen-induced arthritis. Subchondral bone of wild-type (WT) and Fas-knockout (Fas-/-) mice was evaluated by histomorphometry and microcomputerized tomography. Proportions of synovial bone and cartilage progenitors were assessed by flow cytometry. Synovial bone and cartilage progenitors were purified by fluorescence-activated cell sorting and expression of Fas and Fas-induced apoptosis were analyzed in vitro. Results showed that Fas-/- mice developed attenuated arthritis characterized by preserved epiphyseal bone and cartilage. A proportion of the earliest CD200+ bone and cartilage progenitors was reduced in WT mice with arthritis and was unaltered in Fas-/- mice. During osteoblastic differentiation in vitro, CD200+ cells express the highest levels of Fas and are removed by Fas ligation. These results suggest that Fas-induced apoptosis of early CD200+ osteoprogenitor population represents potential mechanism underlying the impaired bone formation in arthritis, so their preservation may represent the bone-protective mechanism during arthritis.-Lazic Mosler, E., Lukac, N., Flegar, D., Fadljevic, M., Radanovic, I., Cvija, H., Kelava, T., Ivcevic, S., Sucur, A., Markotic, A., Katavic, V., Marusic, A., Grcevic, D., Kovacic, N. Fas receptor induces apoptosis of synovial bone and cartilage progenitor populations and promotes bone loss in antigen-induced arthritis.

Combined manual and automated immunophenotypisation identified disease-specific peripheral blood immune subpopulations in rheumatoid arthritis, ankylosing spondylitis and psoriatic arthritis.

OBJECTIVES: Rheumatoid arthritis (RA), ankylosing spondylitis (AS) and psoriatic arthritis (PsA) are associated with abnormal immune cell functions. We combined manual and automated profiling in subpopulations of T-cells, B-cells and monocytes, in parallel to functional testing and clinical correlation. METHODS: Using flow cytometry, we analysed the expression of CCR4, CCR6 and CXCR5 on helper and cyotoxic T-cells, CD32B and CD86 on naïve and memory B-cells, and CCR1, CCR2, CCR4 and CXCR4 on monocytes in chronic high-disease activity patients to identify peripheral blood subpopulations. Cell activation, proliferative capability and osteoclastogenic effects were tested in vitro. Comparison with synovial compartment, clinical data and anti-TNF treatment were added to peripheral blood analysis. RESULTS: PsA had lower double-negative T-cell frequency, while RA had lower double-positive T-cell frequency and expanded Th1-like and cytotoxic T-cell subsets. CD32B expression was increased on naïve and memory B-cells in AS and associated with disease activity. CCR6+ and CXCR5+ cytotoxic T-cells and CD32B+ naïve and memory B-cells were highly enriched within the synovial compartment. T-cells and B-cells from AS exhibited enhanced activation and proliferation in vitro, whereas T-cell conditioned medium from RA produced an increased osteoclastogenic effect. CCR1 and CXCR4 were upregulated on osteoclastogenic monocyte subsets of RA, AS and PsA patients. Bioinformatic Citrus analysis identified additional T-cell, B-cell and monocyte clusters specifically associated with each disease. CONCLUSIONS: By combining manual and automated data analysis, our study revealed several disease-specific immune cell subpopulations, particularly cytotoxic T-cell subsets in RA and memory B-cell subsets in AS, which may serve as an indicator of active disease or possible therapeutic target.

FasL (rs763110) gene polymorphism is not associated with susceptibility to rheumatoid arthritis in Croatian population.

AIM: To investigate the association of FasL gene polymorphism (rs763110) with rheumatoid arthritis occurrence, disease activity, and tumor necrosis factor-α (TNF-α) plasma concentration in Croatian patients, and to conduct an updated meta-analysis. METHODS: This cross-sectional study enrolled 81 patients with rheumatoid arthritis and 94 control patients. After the assessment of the Disease Activity Score (DAS)-28, blood was taken for analysis. DNA was isolated from the whole blood to determine FasL polymorphism (rs763110) by polymerase chain reaction. Protein levels of TNF-α were determined with ELISA. After a detailed literature search, we conducted an updated meta-analysis using the Review Manager 5 software. RESULTS: Rheumatoid arthritis patients had significantly higher TNF-α concentration in plasma (1.65 [1.2-2.42] pg/mL) than controls (0.99 [0.77-1.35] pg/mL, P<0.001). The FasL rs763110 polymorphism was not associated with rheumatoid arthritis occurrence in either codominant, dominant, recessive, overdominant, or log additive model. Furthermore, the rs763110 genotype was not associated with DAS 28 score or TNF-α concentration. After we added our results to an updated meta-analysis, the significant association previously reported for Western Eurasians was abolished. CONCLUSION: Our data suggest that the association between FasL rs763110 polymorphism and RA susceptibility in Western Eurasians observed in previous studies might be overestimated and should be limited to the population of Southwestern Asia until further investigations are performed.

Diameters and bone thickness at the margin of the foramen magnum in dry skulls from pediatric population: a cross-sectional anatomical study.

PURPOSE: The purpose of the study was to estimate the size and bone thickness at the margin of the foramen magnum in a pediatric population. METHODS: Sixty occipital bone specimens from the collection of macerated skulls at the Department of Anatomy, University of Zagreb, were examined and measured using a vernier scale/caliper. For the purpose of analysis, specimens were divided into two age groups: 1-6 years and 7-18 years of age (before and after the fusion of ossification centers in the occipital bone). We measured the following: antero-posterior and transverse diameters of the foramen magnum, bone thicknesses at the basion, opisthion, two paramedial points on the anterior and posterior margins, and at the occipito-squamous junction. RESULTS: Data presented in this study show that diameters of the foramen magnum increase with age, whereas bone thickness shows variable behavior depending on the measured area. CONCLUSIONS: Increases in diameters in specimens from the younger age group and their absence in specimens from older subjects reflect the growth pattern of the basilar part of occipital bone. Variability of bone thickness at the margin of the foramen magnum and lack of its association with age of the subjects may be attributed to various factors and may potentially affect the clinical presentation of compression syndromes at the level of foramen magnum.

Signaling between tumor cells and the host bone marrow microenvironment.

Tumor cells with high skeletal homing affinity express numerous cell surface receptors that bind ligands produced in bone. Upon arrival, these cells survive in the host environment, encompassed in close proximity to bone marrow cells. Interactions between tumor cells and cells of the host microenvironment are essential to not only tumor cell survival but also their activation and proliferation into environment-modifying tumors. Through the production of RANKL, PTHrP, cytokines, and integrins, activated tumor cells stimulate osteoclastogenesis, enhance bone resorption, and subsequently release matrix-bound proteins that further promote tumor growth and bone resorption. In addition, alterations in the TGF-ß/BMP and Wnt signaling pathways via tumor cell growth can either stimulate or suppress osteoblastic bone formation and function, leading to sclerotic or lytic bone disease, respectively. Hence, the presence of tumor cells in bone dysregulates bone remodeling, dramatically impairing skeletal integrity. Furthermore, through complex mechanisms, cells of the immune system interact with tumor cells to further impact bone remodeling. Lastly, with alterations in bone cell activity, the environment is permissive to promoting tumor growth further, suggesting an interdependence between tumor cells and bone cells in metastatic bone disease and multiple myeloma.

Induction of osteoclast progenitors in inflammatory conditions: key to bone destruction in arthritis.

The inflammatory milieu favors recruitment and activation of osteoclasts, and leads to bone destruction as a serious complication associated with arthritis and with other inflammatory processes. The frequency and activity of osteoclast progenitors (OCPs) correspond to arthritis severity, and may be used to monitor disease progression and bone resorption, indicating the need for detailed characterization of the discrete OCP subpopulations. Collectively, current studies suggest that the most potent murine bone marrow OCP population can be identified among lymphoid negative population within the immature myeloid lineage cells, as B220(-)CD3(-)CD11b(-/lo)CD115(+)CD117(+)CX3CR1(+) and possibly also Ter119(-)CD11c(-)CD135(lo)Ly6C(+)RANK(-). In peripheral blood the OCP population bears the monocytoid phenotype B220(-)CD3(-)NK1.1(-)CD11b(+)Ly6C(hi)CD115(+)CX3CR1(+), presumably expressing RANK in committed OCPs. Much less is known about human OCPs and their regulation in arthritis, but the circulating OCP subset is, most probably, comprised among the lymphoid negative population (CD3(-)CD19(-)CD56(-)), within immature monocyte subset (CD11b(+)CD14(+)CD16(-)), expressing receptors for M-CSF and RANKL (CD115(+)RANK(+)). Our preliminary data confirmed positive association between the proportion of peripheral blood OCPs, defined as CD3(-)CD19(-)CD56(-)CD11b(+)CD14(+), and the disease activity score (DAS28) in the follow-up samples from patients with psoriatic arthritis receiving anti-TNF therapy. In addition, we reviewed cytokines and chemokines which, directly or indirectly, activate OCPs and enhance their differentiation potential, thus mediating osteoresorption. Control of the activity and migratory behaviour of OCPs as well as the identification of crucial bone/joint chemotactic mediators represent promising therapeutic targets in arthritis.

Association of systemic and intra-articular osteoclastogenic potential, pro-inflammatory mediators and disease activity with the form of inflammatory arthritis.

PURPOSE: We aimed to assess osteoclastogenic potential of peripheral blood mononuclear cells (PBMC) and synovial fluid-derived mononuclear cells (SFMC) in different forms of arthritis and to correlate it with inflammatory mediators within intra-articular and circulatory compartments. METHODS: Paired PBMC and SFMC samples of patients with rheumatoid arthritis (RA; n = 10) and psoriatic arthritis (PsA; n = 10), and PBMC of healthy controls were cultured to assess osteoclastogenic potential by the number of tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts (OCs) and expression of OC-related genes (receptor activator of nuclear factor-κΒ (RANK), cFMS, and TRAP). Osteoclastogenesis was correlated with the arthritis-related inflammatory indicators in serum and synovial fluid (SF). RESULTS: Number of OCs differentiated from PBMC was significantly higher in RA and PsA compared with control, with RA having more OCs compared with PsA. There was no difference in SFMC OC number between arthritic patients, but RANK expression in OCs differentiated from SFMC was higher in PsA compared with RA. SF of PsA patients more potently induced OC differentiation from control CD3(-)CD19(-)CD56(-)CD11b(+)CD115(+) PBMC compared with RA, paralleled with higher RANK-ligand expression in PsA SFMC. Positive correlations of OC number with erythrocyte sedimentation rate, serum level of CCL2, and PBMC gene expression of interleukin-18 and Fas-ligand were observed. CONCLUSION: Osteoclastogenic potential is systemically enhanced in patients with RA, paralleled by disordered systemic and local expression of proinflammatory mediators, whereas PsA involves specific deregulation in RANKL/RANK axis. Our study reveals arthritis-specific mediators associated with the form of arthritis, indicating clinical relevance for diagnosis and treatment.

In the eye of the beholder - how course delivery affects anatomy education.

BACKGROUND: The COVID-19 pandemic caused major shifts in students' learning strategies as well as teaching environments that profoundly affected the delivery of anatomy courses in medical schools. The Department of Anatomy at the University of Zagreb School of Medicine had a unique experience where the anatomy course in 2019/2020 was first taught in-person before transferring to an online course delivery, while the inverse happened in 2020/2021. The core curriculum, course material and examination criteria were the same in both academic years. The aim of the study was to determine whether course delivery affected students' perceptions of the course and whether it impacted students' engagement and success. METHODS: The students' perceptions of the course were assessed via an anonymous course survey (student evaluation of teaching, SET). The questions in the SET assessed the usefulness of teaching modalities rather than students' satisfaction. Most questions were in the form of statements to which students responded with their level of agreement on a five-point Likert scale. Differences between responses in 2019/2020 and 2020/2021 were analyzed using the Mann-Whitney test. Effect size was estimated using Cliff's delta and association between responses was assessed using Spearman's r coefficient. RESULTS: Students' perceptions were significantly affected by changes in course delivery. Students' success and engagement were higher in 2019/2020 when in-person teaching preceded online teaching. Furthermore, students' views on course organization and the usefulness of continuous assessment were more positive in 2019/2020. Finally, students' perceptions of the usefulness of online materials and activities were more positive in 2019/2020. All comparisons between the two academic years were statistically significant (P ≤ 0.0001 for all comparisons, Mann-Whitney test). CONCLUSIONS: Students' perceptions of the anatomy course were dependent on the teaching environment they were exposed to at the beginning of the course. A transfer from in-person to online course delivery was more successful than vice-versa. This has important implications for structuring hybrid courses in medical education in the future.

rhBMP6 in autologous blood coagulum is a preferred osteoinductive device to rhBMP2 on bovine collagen sponge in the rat ectopic bone formation assay.

Osteoinductive BMPs require a suitable delivery system for treating various pathological conditions of the spine and segmental bone defects. INFUSE, the only commercially available BMP-based osteoinductive device, consisting of rhBMP2 on bovine absorbable collagen sponge (ACS) showed major disadvantages due to serious side effects. A novel osteoinductive device, OSTEOGROW, comprised of rhBMP6 dispersed within autologous blood coagulum (ABC) is a promising therapy for bone regeneration, subjected to several clinical trials for diaphysial bone repair and spinal fusion. In the present study, we have examined the release dynamics showing that the ABC carrier provided a slower, more steady BMP release in comparison to the ACS. Rat subcutaneous assay was employed to evaluate cellular events and the time course of ectopic osteogenesis. The host cellular response to osteoinductive implants was evaluated by flow cytometry, while dynamics of bone formation and maintenance in time were evaluated by histology, immunohistochemistry and micro CT analyses. Flow cytometry revealed that the recruitment of lymphoid cell populations was significantly higher in rhBMP6/ABC implants, while rhBMP2/ACS implants recruited more myeloid populations. Furthermore, rhBMP6/ABC implants more efficiently attracted early and committed progenitor cells. Dynamics of bone formation induced by rhBMP2/ACS was characterized by a delayed endochondral ossification process in comparison to rhBMP6/ABC implants. Besides, rhBMP6/ABC implants induced more ectopic bone volume in all observed time points in comparison to rhBMP2/ACS implants. These results indicate that OSTEOGROW was superior to INFUSE due to ABC's advantages as a carrier and rhBMP6 superior efficacy in inducing bone.

Which clinical variables have the most significant correlation with quality of life evaluated by SF-36 survey in Croatian cohort of patient with ankylosing spondylitis and psoriatic arthritis?

The aim of our study was to assess clinical variables with the best correlation to quality of life (QOL) assessed by medical outcome survey Short-Form 36 (SF-36) in patients with spondyloarthritides, including ankylosing spondylitis (AS) and psoriatic arthritis (PsA). We analyzed the cohort of 54 patients (22 patients with PsA and 32 patients with AS), who filled the Croatian version of SF-36. For each type of arthritis, patients were clinically evaluated using the extensive list of clinical variables categorized into subjective and objective group. For AS patients, subjective and objective variables (spinal mobility measurements, clinical assessment of spinal pain, patient assessments of disease activity and pain) correlated mainly with the physical functioning concept of SF-36. Patients assessments of fatigue correlated with the energy/fatigue subscale, whereas patient assessment of enthesial pain correlated with the pain subscale. Correlations between clinical variables and SF-36 concepts of PsA patients showed more diverse distribution than for AS. Objective variables (spinal mobility measurements, a 76-joint score, clinical assessment of spinal pain) correlated with concepts concerning physical health and pain. Several subjective patient assessments correlated with energy/fatigue, emotional well-being, pain and general health subscales. Both patient and physician assessment of PsA activity correlated with the role limitations due to emotional problems. Bath ankylosing spondylitis functional index (BASFI) had the strongest correlation with the physical functioning concept of SF-36 in both diseases. Our findings provide important information to help selecting the variables with strongest impact on QOL, for better planning the management strategies and achieving better rehabilitation results.

Transcriptome profiling of osteoclast subsets associated with arthritis: A pathogenic role of CCR2hi osteoclast progenitors.

Introduction: The existence of different osteoclast progenitor (OCP) subsets has been confirmed by numerous studies. However, pathological inflammation-induced osteoclastogenesis remains incompletely understood. Detailed characterization of OCP subsets may elucidate the pathophysiology of increased osteoclast activity causing periarticular and systemic bone resorption in arthritis. In our study, we rely on previously defined OCP subsets categorized by the level of CCR2 expression as circulatory-like committed CCR2hi OCPs, which are substantially expanded in arthritis, and marrow-resident CCR2lo OCPs of immature phenotype and behavior. Methods: In order to perform transcriptome characterization of those subsets in the context of collagen-induced arthritis (CIA), we sorted CCR2hi and CCR2lo periarticular bone marrow OCPs of control and arthritic mice, and performed next-generation RNA sequencing (n=4 for each group) to evaluate the differential gene expression profile using gene set enrichment analysis with further validation. Results: A disparity between CCR2hi and CCR2lo subset transcriptomes (863 genes) was detected, with the enrichment of pathways for osteoclast differentiation, chemokine and NOD-like receptor signaling in the CCR2hi OCP subset, and ribosome biogenesis in eukaryotes and ribosome pathways in the CCR2lo OCP subset. The effect of intervention (CIA) within each subset was greater in CCR2hi (92 genes) than in CCR2lo (43 genes) OCPs. Genes associated with the osteoclastogenic pathway (Fcgr1, Socs3), and several genes involved in cell adhesion and migration (F11r, Cd38, Lrg1) identified the CCR2hi subset and distinguish CIA from control group, as validated by qPCR (n=6 for control mice, n=9 for CIA mice). The latter gene set showed a significant positive correlation with arthritis clinical score and frequency of CCR2hi OCPs. Protein-level validation by flow cytometry showed increased proportion of OCPs expressing F11r/CD321, CD38 and Lrg1 in CIA, indicating that they could be used as disease markers. Moreover, osteoclast pathway-identifying genes remained similarly expressed (Fcgr1) or even induced by several fold (Socs3) in preosteoclasts differentiated in vitro from CIA mice compared to pre-cultured levels, suggesting their importance for enhanced osteoclastogenesis of the CCR2hi OCPs in arthritis. Conclusion: Our approach detected differentially expressed genes that could identify distinct subset of OCPs associated with arthritis as well as indicate possible therapeutic targets aimed to modulate osteoclast activity.

Tamoxifen Ameliorates Cholestatic Liver Fibrosis in Mice: Upregulation of TGFß and IL6 Is a Potential Protective Mechanism.

The available treatments for cholestatic liver fibrosis are limited, and the disease often progresses to liver cirrhosis. Tamoxifen is a selective modulator of estrogen receptors, commonly used in breast cancer therapy. A recent in vitro study showed that tamoxifen deactivates hepatic stellate cells, suggesting its potential as an antifibrotic therapeutic, but its effects in vivo remain poorly investigated. In the present study, we show that tamoxifen protects against the cholestatic fibrosis induced by a diet supplemented with 0.025% 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC). Mice fed with a DDC-supplemented diet for four weeks and treated with tamoxifen developed a significantly milder degree of liver fibrosis than vehicle-treated mice, as evidenced by a lower percentage of Sirius red-stained area (60.4% decrease in stained area in male and 42% decrease in female mice, p < 0.001 and p < 0.01, respectively) and by lower hydroxyproline content. The finding was further confirmed by qPCR analysis, which showed a lower expression of genes for Col1a1, Acta2, Sox9, Pdgf, and Krt19, indicating the inhibitory effect on hepatic stellate cells, collagen production, and biliary duct proliferation. The degree of protection was similar in male and female mice. Tamoxifen per se, injected into standard-diet-fed mice, increased the expression of genes for Il6 (p < 0.01 and p < 0.001 in male and female mice, respectively) and Tgfß (p < 0.01 for both sexes), and had no adverse effects. We showed that tamoxifen sex-independently protects against cholestatic DDC-induced liver fibrosis. The increased expression of Il6 and Tgfß seems to be a plausible protective mechanism that should be the primary focus of further research.