Characterization of NEB pathogenic variants in patients reveals novel nemaline myopathy disease mechanisms and omecamtiv mecarbil force effects

Nebulin, a critical protein of the skeletal muscle thin filament, plays important roles in physiological processes such as regulating thin filament length (TFL), cross-bridge cycling, and myofibril alignment. Pathogenic variants in the nebulin gene (NEB) cause NEB-based nemaline myopathy (NEM2), a genetically heterogeneous disorder characterized by hypotonia and muscle weakness, currently lacking curative therapies. In this study, we examined a cohort of ten NEM2 patients, each with unique pathogenic variants, aiming to understand their impact on mRNA, protein, and functional levels. Results show that pathogenic truncation variants affect NEB mRNA stability and lead to nonsense-mediated decay of the mutated transcript. Moreover, a high incidence of cryptic splice site activation was found in patients with pathogenic splicing variants that are expected to disrupt the actin-binding sites of nebulin. Determination of protein levels revealed patients with either relatively normal or markedly reduced nebulin. We observed a positive relation between the reduction in nebulin and a reduction in TFL, or reduction in tension (both maximal and submaximal tension). Interestingly, our study revealed a pathogenic duplication variant in nebulin that resulted in a four-copy gain in the triplicate region of NEB and a much larger nebulin protein and longer TFL. Additionally, we investigated the effect of Omecamtiv mecarbil (OM), a small-molecule activator of cardiac myosin, on force production of type 1 muscle fibers of NEM2 patients. OM treatment substantially increased submaximal tension across all NEM2 patients ranging from 87 to 318%, with the largest effects in patients with the lowest level of nebulin. In summary, this study indicates that post-transcriptional or post-translational mechanisms regulate nebulin expression. Moreover, we propose that the pathomechanism of NEM2 involves not only shortened but also elongated thin filaments, along with the disruption of actin-binding sites resulting from pathogenic splicing variants. Significantly, our findings highlight the potential of OM treatment to improve skeletal muscle function in NEM2 patients, especially those with large reductions in nebulin levels.

Reporting of determinants of health inequities and participant characteristics in randomized controlled trials of systemic lupus erythematosus in Canada: A scoping review

OBJECTIVE

To report participant characteristics relevant to identifying health inequities in systemic lupus erythematosus (SLE) randomized controlled trials conducted in Canada.

METHODS

We conducted a scoping review by searching MEDLINE (Ovid) and Embase (1990 to June 2023), and CENTRAL (inception to June 2023). Eligible studies: used an RCT design; evaluated interventions (pharmacologic and non-pharmacologic) among SLE patients aged ≥18 years; and were conducted in Canada. Data extraction was guided by the Campbell and Cochrane Equity Methods Group's PROGRESS-Plus framework on 11 factors leading to health inequities (Place of residence; Race, culture, ethnicity, and language; Occupation; Gender and sex; Religion; Education; Socioeconomic status; Social capital; Plus: Personal characteristics associated with discrimination; Features of relationships; and Time-dependent relationships).

RESULTS

Of 1901 unique records, 6 met the inclusion criteria. Sex and age were the only PROGRESS factors that were reported in all studies. The majority of participants were female (84.4% to 100%), and mean ages of participants ranged from 42 to 52.3 years. Place of residence, race, education, and social capital were reported in three studies. Socioeconomic status was reported in two studies, and occupation was reported in one study. Religion, features of relationships, and time-dependent relationships were not reported in any included studies.

CONCLUSION

Limited reporting of determinants of health inequities in RCTs for SLE in Canada suggests the need for reporting standards to support equity, diversity, and inclusion practices in research.

"How are you?" Perspectives From Patients and Health Care Providers of Text Messaging to Support Rheumatoid Arthritis Care: A Thematic Analysis

OBJECTIVE

Patients with rheumatoid arthritis (RA) may need to access rheumatology care between scheduled visits. WelTel is a virtual care platform that supports secure two-way text-messaging between patients and their health care team. The objective of the present study was to explore perspectives and experiences of health care providers (HCPs) and patients related to the use of WelTel as an adjunct to routine care.

METHODS

Seventy patients with RA were enrolled in a six-month WelTel pilot project launched in September 2021. Patients received monthly "How are you?" text message check-ins and could message their health care team during clinic hours to request health advice. The current project is a qualitative study of the WelTel pilot. A subgroup of pilot participants was purposively sampled and invited to participate in interviews. A thematic analysis of transcripts was conducted using a deductive approach leveraging quality of care domains.

RESULTS

Thirteen patients (62% female, mean age 62 years, 10 White) completed interviews. Patients' views suggested that text messaging with the rheumatology team supported high-quality care across multiple quality domains including patient-centeredness, timeliness, efficiency, safety, effectiveness, equity, and appropriateness. Seven HCPs (57.1% female, one pharmacist and six rheumatologists) completed interviews. HCPs' perspectives varied based on their experience with the WelTel platform. Additional themes reported by HCPs included perceived increased workload and burnout.

CONCLUSIONS

Patients with RA perceived text-based messaging as supporting high-quality care. The impact of increased communications on HCP burnout and workload requires consideration, and future studies should evaluate the effect of texting on patient outcomes.

ARMC5 controls the degradation of most Pol II subunits, and ARMC5 mutation increases neural tube defect risks in mice and humans

BACKGROUND

Neural tube defects (NTDs) are caused by genetic and environmental factors. ARMC5 is part of a novel ubiquitin ligase specific for POLR2A, the largest subunit of RNA polymerase II (Pol II).

RESULTS

We find that ARMC5 knockout mice have increased incidence of NTDs, such as spina bifida and exencephaly. Surprisingly, the absence of ARMC5 causes the accumulation of not only POLR2A but also most of the other 11 Pol II subunits, indicating that the degradation of the whole Pol II complex is compromised. The enlarged Pol II pool does not lead to generalized Pol II stalling or a generalized decrease in mRNA transcription. In neural progenitor cells, ARMC5 knockout only dysregulates 106 genes, some of which are known to be involved in neural tube development. FOLH1, critical in folate uptake and hence neural tube development, is downregulated in the knockout intestine. We also identify nine deleterious mutations in the ARMC5 gene in 511 patients with myelomeningocele, a severe form of spina bifida. These mutations impair the interaction between ARMC5 and Pol II and reduce Pol II ubiquitination.

CONCLUSIONS

Mutations in ARMC5 increase the risk of NTDs in mice and humans. ARMC5 is part of an E3 controlling the degradation of all 12 subunits of Pol II under physiological conditions. The Pol II pool size might have effects on NTD pathogenesis, and some of the effects might be via the downregulation of FOLH1. Additional mechanistic work is needed to establish the causal effect of the findings on NTD pathogenesis.

From Two Dimensions to Multidimensions: A Mechanistic Model to Support Deliberate CPD Development, Coordination, and Evaluation

INTRODUCTION

The effectiveness of continuing professional development as an intervention to improve health professional behavior and patient health is variable and contentious. To clarify the causal relationships underlying program outcomes and facilitate a necessary shift from outcomes-only-based approaches to outcome-based and theory-based approaches in program development and evaluation, we developed a model of mechanisms mapped to relevant outcomes.

METHODS

Mechanisms identified in a prior realist synthesis of opioid agonist therapy continuing professional development programs were iteratively tested and refined using purposive and opportunistic sampling and realist approaches against two systematic reviews of programs in analgesic prescribing and palliative care. Further testing involved practical application within programs in sustainable health care and pain management.

RESULTS

Ninety reports on 75 programs and practical application to multiple additional programs informed the final model consisting of five distinct mechanisms: motivation transformation, expert influence, confidence development, self-efficacy facilitation, and community of practice expansion. The mechanisms and related analysis emphasize that continuing professional development is heterogeneous, complex, and context dependent.

DISCUSSION

Shifting toward outcome-based and theory-based approaches facilitates further conceptual shifts at intraprogram and interprogram and interintervention levels toward more deliberate program development and evaluation, increased program complementarity and subsequent collaboration. It clarifies opportunities for intercalation of continuing professional development with other intervention sciences. The model presents a resource for practitioners, researchers, and policymakers to advance continuing professional development planning, coordination, and evaluation.

Pain and participation in social activities in people with relapsing remitting and progressive multiple sclerosis

Background

Differences in pain between subtypes of multiple sclerosis are understudied.

Objective

To compare the prevalence of pain, and the association between pain and: (a) pain interference and (b) social participation in people with relapsing-remitting multiple sclerosis and progressive multiple sclerosis.

Methods

Participants completed the McGill Pain Questionnaire Short-Form-2, Pain Effects Scale and Ability to Participate in Social Roles and Activities-V2.0 questionnaires. We tested the association between multiple sclerosis subtype, pain severity, and pain interference/social participation using quantile regression.

Results

Of 231 participants (relapsing-remitting multiple sclerosis: 161, progressive multiple sclerosis: 70), 82.3% were women. The prevalence of pain was 95.2%, of more than mild pain was 38.1%, and of pain-related limitations was 87%; there were no differences between multiple sclerosis subtypes. Compared to participants with relapsing-remitting multiple sclerosis, those with progressive multiple sclerosis reported higher pain interference (mean (standard deviation) Pain Effects Scale; progressive multiple sclerosis: 15[6.0] vs relapsing-remitting multiple sclerosis: 13[5], p = 0.039) and lower social participation (Ability to Participate in Social Roles and Activities T-scores 45[9.0] vs 48.3[8.9], p = 0.011). However, on multivariable analysis accounting for age, physical disability, mood/anxiety and fatigue, multiple sclerosis subtype was not associated with differences in pain interference or social participation.

Conclusions

Pain was nearly ubiquitous. Over one-third of individuals with relapsing-remitting multiple sclerosis and progressive multiple sclerosis reported pronounced pain, although this did not differ by multiple sclerosis subtype.

Well-being and flourishing mental health in adults with inflammatory bowel disease, multiple sclerosis and rheumatoid arthritis in Manitoba, Canada: a cross-sectional study

OBJECTIVES

Among people with immune-mediated inflammatory disease (IMID), including multiple sclerosis (MS), inflammatory bowel disease (IBD) and rheumatoid arthritis (RA) most research has focused on mental illness rather than on mental health. We assessed dimensions of mental health among persons with IMID and compared them across IMID. We also evaluated demographic and clinical characteristics associated with flourishing mental health.

DESIGN

Participants: Adults with an IMID (MS, 239; IBD, 225; RA 134; total 598) who were participating in a cohort study.

SETTING

Tertiary care centre in Manitoba, Canada.

PRIMARY OUTCOME MEASURE

Participants completed the Mental Health Continuum Short-Form (MHC-SF), which measures emotional, psychological and social well-being, and identifies flourishing mental health. This outcome was added midway through the study on the advice of the patient advisory group. Depression, anxiety, pain, fatigue and physical function were also assessed.

RESULTS

Total MHC-SF and subscale scores were similar across IMID groups. Nearly 60% of participants were considered to have flourishing mental health, with similar proportions across disease types (MS 56.5%; IBD 58.7%; RA 59%, p=0.95). Older age was associated with a 2% increased odds of flourishing mental health per year of age (OR 1.02; 95% CI: 1.01 to 1.04). Clinically meaningful elevations in anxiety (OR 0.25; 95% CI: 0.12 to 0.51) and depressive symptoms (OR 0.074; 95% CI: 0.009 to 0.61) were associated with lower odds. Higher levels of pain, anxiety and depressive symptoms were associated with lower total Mental Health Continuum scores at the 50th quantile.

CONCLUSIONS

Over half of people with MS, IBD and RA reported flourishing mental health, with levels similar across the disease groups. Interventions targeting symptoms of depression and anxiety, and upper limb impairments, as well as resilience training may help a higher proportion of the IMID population achieve flourishing mental health.

A single dose of exercise stimulates skeletal muscle mitochondrial plasticity in myotonic dystrophy type 1

AIM

Myotonic dystrophy type 1 (DM1) is the second most common muscular dystrophy after Duchenne and is the most prevalent muscular dystrophy in adults. DM1 patients that participate in aerobic exercise training experience several physiological benefits concomitant with improved muscle mitochondrial function without alterations in typical DM1-specific disease mechanisms, which suggests that correcting organelle health is key to ameliorate the DM1 pathology. However, our understanding of the molecular mechanisms of mitochondrial turnover and dynamics in DM1 skeletal muscle is lacking.

METHODS

Skeletal muscle tissue was sampled from healthy and DM1 mice under sedentary conditions and at several recovery time points following an exhaustive treadmill run.

RESULTS

We demonstrate that DM1 patients exhibit an imbalance in the transcriptional apparatus for mitochondrial turnover and dynamics in skeletal muscle. Additionally, DM1 mice displayed elevated expression of autophagy and mitophagy regulators. A single dose of exercise successfully enhanced canonical exercise molecular pathways and skeletal muscle mitochondrial biogenesis despite failing to alter the cellular pathology in DM1 mice. However, treadmill running stimulated coordinated organelle fusion and fission signaling, as well as improved alternative splicing of Optic atrophy 1. Exercise also evoked autophagy and mitophagy pathways in DM1 skeletal muscle resulting in the normalized expression of autophagy- and lysosome-related machinery responsible for the clearance of dysfunctional organelles.

CONCLUSION

Collectively, our data indicate that mitochondrial dynamics and turnover processes in DM1 skeletal muscle are initiated with a single dose of exercise, which may underlie the adaptive benefits previously documented in DM1 mice and patients.

The Effect of Crosslinking Density on Nasal Chondrocytes' Redifferentiation

Hydrogels appear to be an attractive class of biomaterial for cartilage tissue engineering due to their high water content, excellent biocompatibility, tunable stiffness, etc. The crosslinking density of the hydrogel can affect their viscoelastic property, and therefore potentially impact the chondrogenic phenotype of re-differentiated chondrocytes in a 3D microenvironment through physical cues. To understand the effect of crosslinking densities on chondrocytes phenotype and cellular interaction with the hydrogel, this study utilized a clinical grade thiolate hyaluronic acid and thiolate gelatin (HA-Gel) hydrogel, crosslinked with poly(ethylene glycol) diacrylate to create various crosslinking densities. The HA-Gel hydrogels were then mixed with human nasal chondrocytes to generate neocartilage in vitro. The influence of the hydrogel crosslinking density and the viscoelastic property on the cell behaviours on the gene and matrix levels were evaluated using biochemistry assays, histology, quantitative polymerase chain reaction (qPCR) and next-generation sequencing (RNA seq). In general, the differences in the storage modulus of the HA-Gel hydrogel are not enough to alter the cartilaginous gene expression of chondrocytes. However, a positively correlated trend of PPAR-γ gene expression to the crosslinking density was measured by qPCR. The RNA-seq results have shown that 178 genes are significantly negatively correlated and 225 genes are positively correlated to the crosslinking density, which is worth investigating in the future studies.

Group-based exercice training programs for military members presenting musculoskeletal disorders - protocol for a pragmatic randomized controlled trial

BACKGROUND

Musculoskeletal disorders are a leading cause of morbidity and the most prevalent source of disability among soldiers. Their high prevalence in armed forces and limited ressources have led to problems related to access to physical rehabilitation care. To increase access, supervised group-based exercise programs for the most prevalent musculoskeletal disorders (low back pain, patellofemoral pain, rotator cuff-related shoulder pain or lateral ankle sprain) have been developed at a Canadian Armed forces (CAF) base, but their effectiveness has not been evaluated. The primary objective of this randomized controlled trial is to evaluate the mid- and long-term effects of these group-based training programs on pain severity and functional limitations, in comparison with usual individual physiotherapy care. Secondary objectives include comparing both interventions in terms of health-related quality of life, pain-related fear, and patients' satisfaction.

METHODS

One hundred and twenty soldiers with a new medical referral for physiotherapy services for one of the four targeted musculoskeletal disorders will be consecutively recruited. They will be randomly assigned to either group-based training program or usual individual physiotherapy care, and will take part in the assigned 12-week intervention. There will be four evaluation sessions over 26 weeks (baseline, week 6, 12 and 26). At each follow-up, functional limitations, pain severity, health-related quality of life and pain-related fears will be assessed. Patients satisfaction with treatment will also be evaluated at the end of the intervention period. Either two-way repeated measures ANOVA will be used to analyse and compare the effects of the interventions.

DISCUSSION

This RCT will determine the effectiveness of group-based training programs compared to usual individual physiotherapy care. This new intervention model could represent an efficient, and more pro-active approach to manage a higher number of soldiers with musculoskeletal disorders. It could improve access to physical rehabilitation care and improve the health of soldiers.

TRIAL REGISTRATION

ClinicalTrials.gov ( NCT05235152 ), February 11th 2022.

Adaptation of a Shared Decision-Making Tool for Early Rheumatoid Arthritis Treatment Decisions with Indigenous Patients

Background

Patient decision aids (PtDAs) enable shared decision-making between patients and healthcare providers. Adaptations to PtDAs for use with populations facing inequities in healthcare can improve the relevancy of information presented, incorporate appropriate cultural context, and address health literacy concerns. Our objective was to adapt the Early RA (rheumatoid arthritis) PtDA for use with Canadian Indigenous patients.

Methods

The Early RA PtDA was modified through an iterative process using data obtained from semi-structured interviews of two sequential cohorts of Indigenous patients with RA. Interview data were analyzed using thematic analysis.

Results

Seven participants provided initial feedback on the existing PtDA. The modifications they suggested were made and shared with another nine participants to confirm acceptability and provide further feedback. The first cohort suggested revisions to clarify medical and cost coverage information, include Indigenous traditional healing practice options, simplify text, and include Indigenous images and colors aligned with Canadian Indigenous community representation. Additional revisions were suggested by the second cohort to increase the legibility of the text, insert more Indigenous imagery, address formulary coverage for non-status First Nations patients, and include information about lifestyle factors in managing RA.

Conclusion

Incorporating Indigenous-specific adaptations in the design of PtDAs may increase use and relevancy to support engagement in treatment decisions, thereby supporting health-equity oriented health service interventions. Indigenous patient-specific evidence and translation of key words into the end-users’ Indigenous languages should be included for implementation of the PtDA.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40271-021-00546-8.

Serum metabolic fingerprinting of psoriasis and psoriatic arthritis patients using solid-phase microextraction-liquid chromatography-high-resolution mass spectrometry

INTRODUCTION

Psoriatic arthritis (PsA), an inflammatory arthritis that develops in individuals with psoriasis, is associated with reduced quality of life. Identifying biomarkers associated with development of PsA as well as with PsA disease activity may help management of psoriatic disease.

OBJECTIVES

To use metabolomic fingerprinting to determine potential candidate markers of disease conversion (psoriasis to PsA) and/or PsA activity.

METHODS

A novel sample preparation protocol based on solid-phase microextraction (SPME) was used to prepare serum samples obtained from: (1) individuals with psoriasis, some of whom develop psoriatic arthritis (n = 20); (2) individuals with varying PsA activity (mild, moderate, severe; n = 10 each) and (3) healthy controls (n = 10). Metabolomic fingerprinting of the obtained extracts was performed using reversed-phase liquid chromatography coupled to high resolution mass spectrometry.

RESULTS

Psoriasis patients who developed PsA had similar metabolomic profiles to patients with mild PsA and were also indistinguishable from patients with psoriasis who did not develop PsA. Elevated levels of selected long-chain fatty acids (e.g., 3-hydroxytetradecanedioic acid) that are associated with dysregulation of fatty acid metabolism, were observed in patients with severe PsA. In addition, 1,11-undecanedicarboxylic acid-an unusual fatty acid associated with peroxisomal disorders-was also identified as a classifier in PsA patients vs. healthy individuals. Furthermore, a number of different eicosanoids with either pro- or anti-inflammatory properties were detected solely in serum samples of patients with moderate and severe PsA.

CONCLUSION

A global metabolomics approach was employed to analyze the serum metabolome of patients with psoriasis, PsA, and healthy controls in order to examine potential differences in the biochemical profiles at a metabolite level. A closer examination of circulating metabolites may potentially provide markers of PsA activity.

Community engagement approaches for Indigenous health research: recommendations based on an integrative review

OBJECTIVE

Community engagement practices in Indigenous health research are promoted as a means of decolonising research, but there is no comprehensive synthesis of approaches in the literature. Our aim was to assemble and qualitatively synthesise a comprehensive list of actionable recommendations to enhance community engagement practices with Indigenous peoples in Canada, the USA, Australia and New Zealand.

DESIGN

Integrative review of the literature in medical (Medline, Cumulative Index to Nursing and Allied Health Literature and Embase) and Google and WHO databases (search cut-off date 21 July 2020).

ARTICLE SELECTION

Studies that contained details regarding Indigenous community engagement frameworks, principles or practices in the field of health were included, with exclusion of non-English publications. Two reviewers independently screened the articles in duplicate and reviewed full-text articles.

ANALYSIS

Recommendations for community engagement approaches were extracted and thematically synthesised through content analysis.

RESULTS

A total of 63 studies were included in the review, with 1345 individual recommendations extracted. These were synthesised into a list of 37 recommendations for community engagement approaches in Indigenous health research, categorised by stage of research. In addition, activities applicable to all phases of research were identified: partnership and trust building and active reflection.

CONCLUSIONS

We provide a comprehensive list of recommendations for Indigenous community engagement approaches in health research. A limitation of this review is that it may not address all aspects applicable to specific Indigenous community settings and contexts. We encourage anyone who does research with Indigenous communities to reflect on their practices, encouraging changes in research processes that are strengths based.

Defining predatory journals and responding to the threat they pose: a modified Delphi consensus process

OBJECTIVE

To conduct a Delphi survey informing a consensus definition of predatory journals and publishers.

DESIGN

This is a modified three-round Delphi survey delivered online for the first two rounds and in-person for the third round. Questions encompassed three themes: (1) predatory journal definition; (2) educational outreach and policy initiatives on predatory publishing; and (3) developing technological solutions to stop submissions to predatory journals and other low-quality journals.

PARTICIPANTS

Through snowball and purposive sampling of targeted experts, we identified 45 noted experts in predatory journals and journalology. The international group included funders, academics and representatives of academic institutions, librarians and information scientists, policy makers, journal editors, publishers, researchers involved in studying predatory journals and legitimate journals, and patient partners. In addition, 198 authors of articles discussing predatory journals were invited to participate in round 1.

RESULTS

A total of 115 individuals (107 in round 1 and 45 in rounds 2 and 3) completed the survey on predatory journals and publishers. We reached consensus on 18 items out of a total of 33 to be included in a consensus definition of predatory journals and publishers. We came to consensus on educational outreach and policy initiatives on which to focus, including the development of a single checklist to detect predatory journals and publishers, and public funding to support research in this general area. We identified technological solutions to address the problem: a 'one-stop-shop' website to consolidate information on the topic and a 'predatory journal research observatory' to identify ongoing research and analysis about predatory journals/publishers.

CONCLUSIONS

In bringing together an international group of diverse stakeholders, we were able to use a modified Delphi process to inform the development of a definition of predatory journals and publishers. This definition will help institutions, funders and other stakeholders generate practical guidance on avoiding predatory journals and publishers.

Lithium for Fracture Treatment (LiFT): a double-blind randomised control trial protocol

INTRODUCTION

Fracture healing can fail in up to 10% of cases despite appropriate treatment. While lithium has been the standard treatment for bipolar disorder, it may also have a significant impact to increase bone healing in patients with long bone fractures. To translate this knowledge into clinical practice, a randomised clinical trial (RCT) is proposed.

METHODS AND ANALYSIS

A multicentre double blind, placebo-controlled RCT is proposed to evaluate the efficacy of lithium to increase the rate and predictability of long bone fracture healing in healthy adults compared to lactose placebo treatment. 160 healthy individuals from 18 to 55 years of age presenting with shaft fractures of the femur, tibia/fibula, humerus or clavicle will be eligible. Fractures will be randomised to placebo (lactose) or treatment (300 mg lithium carbonate) group within 2 weeks of the injury. The primary outcome measure will be radiographic union defined as visible callus bridging on three of the four cortices at the fracture site using a validated radiographic union score. Secondary outcome measures will include functional assessment and pain scoring.

ETHICS AND DISSEMINATION

Participant confidentiality will be maintained with publication of results. Research Ethics Board Approval: Sunnybrook Research Institute (REB # 356-2016). Health Canada Approval (HC6-24-C201560). Results of the main trial and secondary endpoints will be submitted for publication in a peer-reviewed journal and presented at conferences.

TRIAL REGISTRATION NUMBER

NCT02999022.

Cancer-associated fibroblasts induce epithelial-mesenchymal transition of bladder cancer cells through paracrine IL-6 signalling

BACKGROUND

Cancer-associated fibroblasts (CAFs), activated by tumour cells, are the predominant type of stromal cells in cancer tissue and play an important role in interacting with neoplastic cells to promote cancer progression. Epithelial-mesenchymal transition (EMT) is a key feature of metastatic cells. However, the mechanism by which CAFs induce EMT program in bladder cancer cells remains unclear.

METHODS

To investigate the role of CAFs in bladder cancer progression, healthy primary bladder fibroblasts (HFs) were induced into CAFs (iCAFs) by bladder cancer-derived exosomes. Effect of conditioned medium from iCAFs (CM iCAF) on EMT markers expression of non-invasive RT4 bladder cancer cell line was determined by qPCR and Western blot. IL6 expression in iCAFs was evaluated by ELISA and Western blot. RT4 cell proliferation, migration and invasion were assessed in CM iCAF +/- anti-IL6 neutralizing antibody using cyQUANT assay, scratch test and transwell chamber respectively. We investigated IL6 expression relevance for bladder cancer progression by querying gene expression datasets of human bladder cancer specimens from TCGA and GEO genomic data platforms.

RESULTS

Cancer exosome-treated HFs showed CAFs characteristics with high expression levels of αSMA and FAP. We showed that the CM iCAF induces the upregulation of mesenchymal markers, such as N-cadherin and vimentin, while repressing epithelial markers E-cadherin and p-ß-catenin expression in non-invasive RT4 cells. Moreover, EMT transcription factors SNAIL1, TWIST1 and ZEB1 were upregulated in CM iCAF-cultured RT4 cells compared to control. We also showed that the IL-6 cytokine was highly expressed by CAFs, and its receptor IL-6R was found on RT4 bladder cancer cells. The culture of RT4 bladder cancer cells with CM iCAF resulted in markedly promoted cell growth, migration and invasion. Importantly, inhibition of CAFs-secreted IL-6 by neutralizing antibody significantly reversed the IL-6-induced EMT phenotype, suggesting that this cytokine is necessary for CAF-induced EMT in the progression of human bladder cancer. Finally, we observed that IL6 expression is up-regulated in aggressive bladder cancer and correlate with CAF marker ACTA2.

CONCLUSIONS

We conclude that CAFs promote aggressive phenotypes of non-invasive bladder cancer cells through an EMT induced by the secretion of IL-6.

Stereotypic generation of axial tenocytes from bipartite sclerotome domains in zebrafish

Development of a functional musculoskeletal system requires coordinated generation of muscles, bones, and tendons. However, how axial tendon cells (tenocytes) are generated during embryo development is still poorly understood. Here, we show that axial tenocytes arise from the sclerotome in zebrafish. In contrast to mouse and chick, the zebrafish sclerotome consists of two separate domains: a ventral domain and a previously undescribed dorsal domain. While dispensable for sclerotome induction, Hedgehog (Hh) signaling is required for the migration and maintenance of sclerotome derived cells. Axial tenocytes are located along the myotendinous junction (MTJ), extending long cellular processes into the intersomitic space. Using time-lapse imaging, we show that both sclerotome domains contribute to tenocytes in a dynamic and stereotypic manner. Tenocytes along a given MTJ always arise from the sclerotome of the adjacent anterior somite. Inhibition of Hh signaling results in loss of tenocytes and enhanced sensitivity to muscle detachment. Together, our work shows that axial tenocytes in zebrafish originate from the sclerotome and are essential for maintaining muscle integrity.

The coordinated generation of bones, muscles and tendons at the correct time and location is critical for the development of a functional musculoskeletal system. Although it is well known that tendon is the connective tissue that attaches muscles to bones, it is still poorly understood how tendon cells, or tenocytes, are generated during embryo development. Using the zebrafish model, we identify trunk tenocytes located along the boundary of muscle segments. Using cell tracing in live animals, we find that tenocytes originate from the sclerotome, an embryonic structure that is previously known to generate the trunk skeleton. In contrast to higher vertebrates, the zebrafish sclerotome consists of two separate domains, a ventral domain and a novel dorsal domain. Both domains give rise to trunk tenocytes in a dynamic and stereotypic manner. Hedgehog (Hh) signaling, an important cell signaling pathway, is not required for sclerotome induction but essential for the generation of sclerotome derived cells. Inhibition of Hh signaling leads to loss of tenocytes and increased sensitivity to muscle detachment. Thus, our work shows that tenocytes develop from the sclerotome and play an important role in maintaining muscle integrity.

Resolving Macrophages Counter Osteolysis by Anabolic Actions on Bone Cells

Progression of inflammatory osteolytic diseases, including rheumatoid arthritis and periodontitis, is characterized by increased production of proinflammatory mediators and matrix-degrading enzymes by macrophages and increased osteoclastic activity. Phenotypic changes in macrophages are central to the healing process in virtually all tissues. Using a murine model of periodontitis, we assessed the timing of macrophage phenotypic changes and the impact of proresolving activation during inflammatory osteolysis and healing. Proinflammatory macrophage activation and TNF-α overproduction within 3 wk after induction of periodontitis was associated with progressing bone loss. Proresolving activation within 1 wk of stimulus removal and markers of resolving macrophages (IL-10, TGF-β, and CD206) correlated strongly with bone levels. In vivo macrophage depletion with clodronate liposomes prevented bone resorption but impaired regeneration. Induction of resolving macrophages with rosiglitazone, a PPAR-γ agonist, led to reduced bone resorption during inflammatory stimulation and increased bone formation during healing. In vitro assessment of primary bone marrow-derived macrophages activated with either IFN-γ and LPS (proinflammatory activation) or IL-4 (proresolving activation) showed that IL-4-activated cells have enhanced resolving functions (production of anti-inflammatory cytokines; migration and phagocytosis of aged neutrophils) and exert direct anabolic actions on bone cells. Cystatin C secreted by resolving but not inflammatory macrophages explained, in part, the macrophage actions on osteoblasts and osteoclasts. This study supports the concept that therapeutic induction of proresolving functions in macrophages can recouple bone resorption and formation in inflammatory osteolytic diseases.

Development of a research platform for children with arthrogryposis multiplex congenita: study protocol for a pilot registry

INTRODUCTION

Arthrogryposis multiplex congenita (AMC) describes a heterogeneous group of conditions with multiple congenital contractures. These conditions may be attributed to genetic or other factors inducing decreased fetal movements, including maternal and paternal factors. Discovering the underlying genetic pathways has important repercussions for prevention, gene therapy and genetic counselling. The current literature mainly consists of small-scale, single-site studies, limiting comparability and pooling of findings across individual studies. A pilot registry for children presenting with AMC is proposed to provide the framework for a large-scale AMC registry. This registry will provide the platform to support high-quality studies to inform the distribution, clinical practice and genetics contributing to this group of conditions.

METHODS AND ANALYSIS

The registry will be piloted on 40 families of children from birth to 21 years of age presenting with AMC. Data will be collected on the child (demographic and newborn variables), mother and father (demographic, lifestyle habits and medical history). To promote standardised data collection, a manual of operations will be developed. Descriptive statistics will be used to summarise relevant data, regression analyses will be used to explore associations to generate hypotheses regarding factors contributing to AMC. Qualitative analysis will also be used to better describe the various phenotypes.

ETHICS AND DISSEMINATION

Ethics approval was obtained at the participating sites. The pilot registry will provide the platform for multisite AMC registry that will generate multiple research avenues to enhance current care and establish new therapies. Following this pilot study, the participant selection criteria will be refined and datasets will be expanded to include rehabilitation and surgical interventions, and genetic sequencing. The best timing for the questionnaire administration and frequency of follow-up prior to the implementation of a multisite AMC registry will be determined.

Vegetarian-style dietary pattern during adolescence has long-term positive impact on bone from adolescence to young adulthood: a longitudinal study

BACKGROUND

The amount of bone accrued during adolescence is an important determinant of later osteoporosis risk. Little is known about the influence of dietary patterns (DPs) on the bone during adolescence and their potential long-term implications into adulthood. We examined the role of adolescent DPs on adolescent and young adult bone and change in DPs from adolescence to young adulthood.

METHODS

We recruited participants from the Saskatchewan Pediatric Bone Mineral Accrual Study (1991-2011). Data from 125 participants (53 females) for adolescent analysis (age 12.7 ± 2 years) and 115 participants (51 females) for adult analysis (age 28.2 ± 3 years) were included. Bone mineral content (BMC) and areal bone mineral density (aBMD) of total body (TB), femoral neck (FN) and lumbar spine (LS) were measured using dual-energy X-ray absorptiometry. Adolescent dietary intake data from multiple 24-h recalls were summarized into 25 food group intakes and were used in the principal component analysis to derive DPs during adolescence. Associations between adolescent DPs and adolescent or adult BMC/BMD were analyzed using multiple linear regression and multivariate analysis of covariance while adjusting for sex, age, the age of peak height velocity, height, weight, physical activity and total energy intake. Generalized estimating equations were used for tracking DPs.

RESULTS

We derived five DPs including "Vegetarian-style", "Western-like", "High-fat, high-protein", "Mixed" and "Snack" DPs. The "Vegetarian-style" DP was a positive independent predictor of adolescent TBBMC, and adult TBBMC, TBaBMD (P < 0.05). Mean adolescent TBaBMD and young adult TBBMC, TBaBMD, FNBMC and FNaBMD were 5%, 8.5%, 6%, 10.6% and 9% higher, respectively, in third quartile of "Vegetarian-style" DP compared to first quartile (P < 0.05). We found a moderate tracking (0.47-0.63, P < 0.001) in DP scores at individual levels from adolescence to adulthood. There were an upward trend in adherence to "Vegetarian-style" DP and an downward trend in adherence to "High-fat, high-protein" DP from adolescence to young adulthood (P < 0.01).

CONCLUSION

A "Vegetarian-style" DP rich in dark green vegetables, eggs, non-refined grains, 100% fruit juice, legumes/nuts/seeds, added fats, fruits and low-fat milk during adolescence is positively associated with bone health.

Estimating annual prevalence of depression and anxiety disorder in multiple sclerosis using administrative data

OBJECTIVE

Researchers have developed case definitions to estimate incidence and lifetime prevalence of depression and anxiety disorders in multiple sclerosis (MS) using administrative data. For policymakers however, the prevalence of a disease requiring ongoing treatment during a given period such as annual period prevalence may be more relevant for decision-making. We tested a case definition for annual period prevalence of depression and anxiety disorders in MS using administrative data.

RESULTS

Using population-based administrative (health claims) data from Manitoba, Canada we identified 1922 persons with incident MS from 1989 to 2012, and 11,392 age, sex and geographically-matched controls from the general population. As compared to controls, MS patients had an elevated annual prevalence ratio of depression (1.77; 95% confidence interval [CI] 1.64, 1.91), and anxiety disorders (1.46; 95% CI 1.35, 1.58). The annual prevalence of depression in our matched cohort was similar to that observed in the 2012 Canadian Community Health Survey, although the annual prevalence of anxiety was slightly higher. Administrative data can be used to estimate the annual period prevalence of psychiatric disorders in MS.

A composite docking approach for the identification and characterization of ectosteric inhibitors of cathepsin K

Cathepsin K (CatK) is a cysteine protease that plays an important role in mammalian intra- and extracellular protein turnover and is known for its unique and potent collagenase activity. Through studies on the mechanism of its collagenase activity, selective ectosteric sites were identified that are remote from the active site. Inhibitors targeting these ectosteric sites are collagenase selective and do not interfere with other proteolytic activities of the enzyme. Potential ectosteric inhibitors were identified using a computational approach to screen the druggable subset of and the entire 281,987 compounds comprising Chemical Repository library of the National Cancer Institute-Developmental Therapeutics Program (NCI-DTP). Compounds were scored based on their affinity for the ectosteric site. Here we compared the scores of three individual molecular docking methods with that of a composite score of all three methods together. The composite docking method was up to five-fold more effective at identifying potent collagenase inhibitors (IC50 < 20 μM) than the individual methods. Of 160 top compounds tested in enzymatic assays, 28 compounds revealed blocking of the collagenase activity of CatK at 100 μM. Two compounds exhibited IC50 values below 5 μM corresponding to a molar protease:inhibitor concentration of <1:12. Both compounds were subsequently tested in osteoclast bone resorption assays where the most potent inhibitor, 10-[2-[bis(2-hydroxyethyl)amino]ethyl]-7,8-diethylbenzo[g]pteridine-2,4-dione, (NSC-374902), displayed an inhibition of bone resorption with an IC50-value of approximately 300 nM and no cell toxicity effects.

Methods for analyzing observational longitudinal prognosis studies for rheumatic diseases: a review & worked example using a clinic-based cohort of juvenile dermatomyositis patients

Most outcome studies of rheumatic diseases report outcomes ascertained on a single occasion. While single assessments are sufficient for terminal or irreversible outcomes, they may not be sufficiently informative if outcomes change or fluctuate over time. Consequently, longitudinal studies that measure non-terminal outcomes repeatedly afford a better understanding of disease evolution.Longitudinal studies require special analytic methods. Newer longitudinal analytic methods have evolved tremendously to deal with common challenges in longitudinal observational studies. In recent years, an increasing number of studies have used longitudinal design. This review aims to help readers understand and apply the findings from longitudinal studies. Using a cohort of children with juvenile dermatomyositis (JDM), we illustrate how to study evolution of disease activity in JDM using longitudinal methods.

TryCYCLE: A Prospective Study of the Safety and Feasibility of Early In-Bed Cycling in Mechanically Ventilated Patients

Introduction

The objective of this study was to assess the safety and feasibility of in-bed cycling started within the first 4 days of mechanical ventilation (MV) to inform a future randomized clinical trial.

Methods

We conducted a 33-patient prospective cohort study in a 21-bed adult academic medical-surgical intensive care unit (ICU) in Hamilton, ON, Canada. We included adult patients (≥ 18 years) receiving MV who walked independently pre-ICU. Our intervention was 30 minutes of in-bed supine cycling 6 days/week in the ICU. Our primary outcome was Safety (termination), measured as events prompting cycling termination; secondary Safety (disconnection or dislodgement) outcomes included catheter/tube dislodgements. Feasibility was measured as consent rate and fidelity to intervention. For our primary outcome, we calculated the binary proportion and 95% confidence interval (CI).

Results

From 10/2013-8/2014, we obtained consent from 34 of 37 patients approached (91.9%), 33 of whom received in-bed cycling. Of those who cycled, 16(48.4%) were female, the mean (SD) age was 65.8(12.2) years, and APACHE II score was 24.3(6.7); 29(87.9%) had medical admitting diagnoses. Cycling termination was infrequent (2.0%, 95% CI: 0.8%-4.9%) and no device dislodgements occurred. Cycling began a median [IQR] of 3 [2, 4] days after ICU admission; patients received 5 [3, 8] cycling sessions with a median duration of 30.7 [21.6, 30.8] minutes per session. During 205 total cycling sessions, patients were receiving invasive MV (150 [73.1%]), vasopressors (6 [2.9%]), sedative or analgesic infusions (77 [37.6%]) and dialysis (4 [2.0%]).

Conclusions

Early cycling within the first 4 days of MV among hemodynamically stable patients is safe and feasible. Research to evaluate the effect of early cycling on patient function is warranted.

Trial Registration

Clinicaltrials.gov: NCT01885442