Lithium Ions as Modulators of Complex Biological Processes: The Conundrum of Multiple Targets, Responsiveness and Non-Responsiveness, and the Potential to Prevent or Correct Dysregulation of Systems during Aging and in Disease.

Lithium is one of the lightest elements on Earth and it has been in the environment since the formation of the galaxy. While a common element, it has not been found to be an essential element in biological processes, ranging from single cell organisms to Homo sapiens. Instead, at an early stage of evolution, organisms committed to a range of elements such as sodium, potassium, calcium, magnesium, zinc, and iron to serve essential functions. Such ions serve critical functions in ion channels, as co-factors in enzymes, as a cofactor in oxygen transport, in DNA replication, as a storage molecule in bone and liver, and in a variety of other roles in biological processes. While seemingly excluded from a major essential role in such processes, lithium ions appear to be able to modulate a variety of biological processes and "correct" deviation from normal activity, as a deficiency of lithium can have biological consequences. Lithium salts are found in low levels in many foods and water supplies, but the effectiveness of Li salts to affect biological systems came to recent prominence with the work of Cade, who reported that administrating Li salts calmed guinea pigs and was subsequently effective at relatively high doses to "normalize" a subset of patients with bipolar disorders. Because of its ability to modulate many biological pathways and processes (e.g., cyclic AMP, GSK-3beta, inositol metabolism, NaK ATPases, neuro processes and centers, immune-related events, respectively) both in vitro and in vivo and during development and adult life, Li salts have become both a useful tool to better understand the molecular regulation of such processes and to also provide insights into altered biological processes in vivo during aging and in disease states. While the range of targets for lithium action supports its possible role as a modulator of biological dysregulation, it presents a conundrum for researchers attempting to elucidate its specific primary target in different tissues in vivo. This review will discuss aspects of the state of knowledge regarding some of the systems that can be influenced, focusing on those involving neural and autoimmunity as examples, some of the mechanisms involved, examples of how Li salts can be used to study model systems, as well as suggesting areas where the use of Li salts could lead to additional insights into both disease mechanisms and natural processes at the molecular and cell levels. In addition, caveats regarding lithium doses used, the strengths and weaknesses of rodent models, the background genetics of the strain of mice or rats employed, and the sex of the animals or the cells used, are discussed. Low-dose lithium may have excellent potential, alone or in combination with other interventions to prevent or alleviate aging-associated conditions and disease progression.

Collagen integrity of the annulus fibrosus in degenerative disc disease individuals quantified with collagen hybridizing peptide.

Introduction: Degenerative disc disease (DDD) is accompanied by structural changes in the intervertebral discs (IVD). Extra-cellular matrix degradation of the annulus fibrosus (AF) has been linked with degeneration of the IVD. Collagen is a vital component of the IVD. Collagen hybridizing peptide (CHP) is an engineered protein that binds to degraded collagen, which we used to quantify collagen damage in AF. This method was used to compare AF samples obtained from donors with no DDD to AF samples from patients undergoing surgery for symptomatic DDD. Methods: Fresh AF tissue was embedded in an optimal cutting temperature compound and cryosectioned at a thickness of 8 µm. Hematoxylin and Eosin staining was performed on sections for general histomorphological assessment. Serial sections were stained with Cy3-conjugated CHP and the mean fluorescence intensity and areal fraction of Cy3-positive staining were averaged for three regions of interest (ROI) on each CHP-stained section. Results: Increases in mean fluorescence intensity (p = 0.0004) and percentage of positively stained area (p = 0.00008) with CHP were detected in DDD samples compared to the non-DDD samples. Significant correlations were observed between mean fluorescence intensity and percentage of positively stained area for both non-DDD (R = 0.98, p = 5E-8) and DDD (R = 0.79, p = 0.0012) samples. No significant differences were detected between sex and the lumbar disc level subgroups of the non-DDD and DDD groups. Only tissue pathology (non-DDD versus DDD) influenced the measured parameters. No three-way interactions between tissue pathology, sex, and lumbar disc level were observed. Discussion and Conclusions: These findings suggest that AF collagen degradation is greater in DDD samples compared to non-DDD samples, as evidenced by the increased CHP staining. Strong positive correlations between the two measured parameters suggest that when collagen degradation occurs, it is detected by this technique and is widespread throughout the tissue. This study provides new insights into the structural alterations associated with collagen degradation in the AF that occur during DDD.

Participants' perceived benefits from the GLA:D™ program for individuals living with hip and knee osteoarthritis: a qualitative study.

BACKGROUND: The Good Life with osteoArthritis: Denmark (GLA:D™), an evidence-based education and exercise program designed for conservative management of knee and hip osteoarthritis (OA), has been shown to benefit participants by reducing pain, improving function, and quality of life. Standardized reporting in the GLA:D databases enabled the measurement of self-reported and performance-based outcomes. There is a paucity of qualitative research on the participants' perceptions of this program, and it is important to understand whether participants' perceptions of the benefits of the program align with reported quantitative findings. METHODS: We conducted semi-structured telephone interviews with individuals who participated in the GLA:D program from January 2017 to December 2018 in Alberta, Canada. Data were analyzed using an interpretive description approach and thematic analysis to identify emergent themes and sub-themes associated with participants perceived benefits of the GLA:D program. We analyzed the data using NVivo Pro software. Member checking and bracketing were used to ensure the rigour of the analysis. RESULTS: 30 participants were interviewed (70% female, 57% rural, 73% knee OA). Most participants felt the program positively benefited them. Two themes emerged from the analysis: wellness and self-efficacy. Participants felt the program benefited their wellness, particularly with regard to pain relief, and improvements in mobility, strength, and overall well-being. Participants felt the program benefited them by promoting a sense of self-efficacy through improving the confidence to perform exercise and routine activities, as well as awareness, and motivation to manage their OA symptoms. Twenty percent of participants felt no benefits from the program due to experiencing increased pain and feeling their OA was too severe to participate. DISCUSSION: The GLA:D program was viewed as beneficial to most participants, this study also identified factors (e.g., severe OA, extreme pain) as to why some participants did not experience meaningful improvements. Early intervention with the GLA:D program prior to individuals experiencing severe OA could help increase the number of participants who experience benefits from their participation. CONCLUSION: As the GLA:D program expands across jurisdictions, providers of the program may consider recruitment earlier in disease progression and targeting those with mild and moderate OA.

A novel scaffold-free mesenchymal stem cell-derived tissue engineered construct for articular cartilage restoration - From basic to clinic.

Treatments for articular cartilage injuries are still challenging, due in part to its avascular and aneural surroundings. Since the first report of autologous chondrocyte implantation, cell-based therapies have been extensively studied with a variety of cell sources, including chondrocytes and mesenchymal stem/stromal cells (MSCs). Recently, MSC-based therapy has received considerable research attention because of the relative ease in handling for tissue harvest, and subsequent cell expansion and differentiation. Using such cells, we have originally developed a 3-dimensional scaffold-free tissue-engineered construct (TEC) through simple-cell culture methods and demonstrated its feasibility for cartilage repair and regeneration in the first-in-human clinical trial. This review summarizes our novel scaffold-free approaches to use MSC for the restoration of damaged articular cartilage, documenting the progression from basic to clinical studies.

Chondrocyte deformation during the unloading phase of cyclic compression loading.

Cell volume and shape changes play a pivotal role in cellular mechanotransduction, governing cellular responses to external loading. Understanding the dynamics of cell behavior under loading conditions is essential to elucidate cell adaptation mechanisms in physiological and pathological contexts. In this study, we investigated the effects of dynamic cyclic compression loading on cell volume and shape changes, comparing them with static conditions. Using a custom-designed platform which allowed for simultaneous loading and imaging of cartilage tissue, tissues were subjected to 100 cycles of mechanical loading while measuring cell volume and shape alterations during the unloading phase at specific time points. The findings revealed a transient decrease in cell volume (13%) during the early cycles, followed by a gradual recovery to baseline levels after approximately 20 cycles, despite the cartilage tissue not being fully recovered at the unloading phase. This observed pattern indicates a temporal cell volume response that may be associated with cellular adaptation to the mechanical stimulus through mechanisms related to active cell volume regulation. Additionally, this study demonstrated that cell volume and shape responses during dynamic loading were significantly distinct from those observed under static conditions. Such findings suggest that cells in their natural tissue environment perceive and respond differently to dynamic compared to static mechanical cues, highlighting the significance of considering dynamic loading environments in studies related to cellular mechanics. Overall, this research contributes to the broader understanding of cellular behavior under mechanical stimuli, providing valuable insights into their ability to adapt to dynamic mechanical loading.

Extracellular Vesicles Generated by Mesenchymal Stem Cells in Stirred Suspension Bioreactors Promote Angiogenesis in Human-Brain-Derived Endothelial Cells.

Interrupted blood flow in the brain due to ischemic injuries such as ischemic stroke or traumatic brain injury results in irreversible brain damage, leading to cognitive impairment associated with inflammation, disruption of the blood-brain barrier (BBB), and cell death. Since the BBB only allows entry to a small class of drugs, many drugs used to treat ischemia in other tissues have failed in brain-related disorders. The administration of mesenchymal stem cell (MSC)-derived extracellular vesicles (EVs) has shown promise in improving the functional recovery of the brain following cerebral ischemia by inducing blood vessel formation. To facilitate such a treatment approach, it is necessary to develop bioprocesses that can produce therapeutically relevant MSC-EVs in a reproducible and scalable manner. This study evaluated the feasibility of using stirred suspension bioreactors (SSBs) to scale-up the serum-free production of pro-angiogenic MSC-EVs under clinically relevant physioxic conditions. It was found that MSCs grown in SSBs generated EVs that stimulated angiogenesis in cerebral microvascular endothelial cells, supporting the use of SSBs to produce MSC-EVs for application in cerebral ischemia. These properties were impaired at higher cell confluency, outlining the importance of considering the time of harvest when developing bioprocesses to manufacture EV populations.

Effect of prebiotic fiber on physical function and gut microbiota in adults, mostly women, with knee osteoarthritis and obesity: a randomized controlled trial.

PURPOSE: Obesity is a primary risk factor for knee osteoarthritis (OA). Prebiotics enhance beneficial gut microbes and can reduce body fat and inflammation. Our objective was to examine if a 6-month prebiotic intervention improved physical function in adults with knee osteoarthritis and obesity. We also measured knee pain, body composition, quality of life, gut microbiota, inflammatory markers, and serum metabolomics. METHODS: Adults (n = 54, mostly women) with co-morbid obesity (BMI > 30 kg/m2) and unilateral/bilateral knee OA were randomly assigned to prebiotic (oligofructose-enriched inulin; 16 g/day; n = 31) or isocaloric placebo (maltodextrin; n = 21) for 6 months. Performance based-tests, knee pain, quality of life, serum metabolomics and inflammatory markers, and fecal microbiota and short-chain fatty acids were assessed. RESULTS: Significant between group differences were detected for the change in timed-up-and-go test, 40 m fast paced walk test, and hand grip strength test from baseline that favored prebiotic over placebo. Prebiotic also reduced trunk fat mass (kg) at 6 months and trunk fat (%) at 3 months compared to placebo. There was a trend (p = 0.059) for reduced knee pain at 6 months with prebiotic versus placebo. In gut microbiota analysis, a total of 37 amplicon sequence variants differed between groups. Bifidobacterium abundance was positively correlated with distance walked in the 6-min walk test and hand grip strength. At 6 months, there was a significant separation of serum metabolites between groups with upregulation of phenylalanine and tyrosine metabolism with prebiotic. CONCLUSION: Prebiotics may hold promise for conservative management of knee osteoarthritis in adults with obesity and larger trials are warranted. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov/study/NCT04172688.

The Heterogeneity of Post-Menopausal Disease Risk: Could the Basis for Why Only Subsets of Females Are Affected Be Due to a Reversible Epigenetic Modification System Associated with Puberty, Menstrual Cycles, Pregnancy and Lactation, and, Ultimately, Menopause?

For much of human evolution, the average lifespan was <40 years, due in part to disease, infant mortality, predators, food insecurity, and, for females, complications of childbirth. Thus, for much of evolution, many females did not reach the age of menopause (45-50 years of age) and it is mainly in the past several hundred years that the lifespan has been extended to >75 years, primarily due to public health advances, medical interventions, antibiotics, and nutrition. Therefore, the underlying biological mechanisms responsible for disease risk following menopause must have evolved during the complex processes leading to Homo sapiens to serve functions in the pre-menopausal state. Furthermore, as a primary function for the survival of the species is effective reproduction, it is likely that most of the advantages of having such post-menopausal risks relate to reproduction and the ability to address environmental stresses. This opinion/perspective will be discussed in the context of how such post-menopausal risks could enhance reproduction, with improved survival of offspring, and perhaps why such risks are preserved. Not all post-menopausal females exhibit risk for this set of diseases, and those who do develop such diseases do not have all of the conditions. The diseases of the post-menopausal state do not operate as a unified complex, but as independent variables, with the potential for some overlap. The how and why there would be such heterogeneity if the risk factors serve essential functions during the reproductive years is also discussed and the concept of sets of reversible epigenetic changes associated with puberty, pregnancy, and lactation is offered to explain the observations regarding the distribution of post-menopausal conditions and their potential roles in reproduction. While the involvement of an epigenetic system with a dynamic "modification-demodification-remodification" paradigm contributing to disease risk is a hypothesis at this point, validation of it could lead to a better understanding of post-menopausal disease risk in the context of reproduction with commonalities may also lead to future improved interventions to control such risk after menopause.

Optimizing tendon repair and regeneration: how does the in vivo environment shape outcomes following rupture of a tendon such as the Achilles tendon?

Risk for rupture of the Achilles tendon, and other tendons increases with age. Such injuries of tissues that function in high load environments generally are believed to heal with variable outcome. However, in many cases, the healing does not lead to a good outcome and the patient cannot return to the previous level of participation in active living activities, including sports. In the past few years, using proteomic approaches and other biological techniques, reports have appeared that identify biomarkers that are prognostic of good outcomes from healing, and others that are destined for poor outcomes using validated criteria at 1-year post injury. This review will discuss some of these recent findings and their potential implications for improving outcomes following connective tissue injuries, as well as implications for how clinical research and clinical trials may be conducted in the future where the goal is to assess the impact of specific interventions on the healing process, as well as focusing the emphasis on regeneration and not just repair.

'I do hope more people can benefit from it.': The qualitative experience of individuals living with osteoarthritis who participated in the GLA:D™ program in Alberta, Canada.

INTRODUCTION: The Good Life with osteoArthritis: Denmark (GLA:DTM) is an evidence-based program designed for individuals with symptomatic hip and knee osteoarthritis (OA). This program has reported improvement in pain, quality of life and self-efficacy, as well as delays in joint replacement surgery for adults with moderate to severe hip or knee OA. Evaluations of GLA:DTM implementation in several countries have focused on effectiveness, training, and feasibility of the program primarily from the provider perspective. Our objective was to examine how the GLA:DTM program was perceived and experienced by individuals with hip and knee OA to inform on-going program refinement and implementation. METHODS: Thirty semi-structured telephone interviews were conducted with participants who completed the GLA:DTM program in Alberta. An interpretive description approach was used to frame the study and thematic analysis was used to code the data and identify emergent themes and sub-themes associated with participants' experience and perception of the GLA:DTM program. RESULTS: Most participants had a positive experience of the GLA:DTM program and particularly enjoyed the group format, although some participants felt the group format prevented one-on-one support from providers. Three emergent themes related to acceptability were identified: accessible, adaptable, and supportive. Participants found the program to be accessible in terms of location, cost, and scheduling. They also felt the program was adaptable and allowed for individual attention and translatability into other settings. Finally, most participants found the group format to be motivating and fostered connections between participants. CONCLUSION: The GLA:DTM program was perceived as acceptable by most participants, yet the group format may not be useful for all individuals living with OA. Recommended improvements included adapting screening to identify those suited for the group format, providing program access earlier in the disease progression trajectory, modifying educational content based on participants' knowledge of OA and finally, providing refresher sessions after program completion.

Towards understanding how bisphosphonate-dependent alterations to nutrient canal integrity can contribute to risk for atypical femoral fractures: Biomechanical considerations and potential relationship to a real-world analogy.

Bisphosphonates are a class of drugs which have shown good efficacy in the treatment of post-menopausal osteoporosis, as well as a good safety profile. However, side-effects such as risk for atypical femoral fractures (AFF) have appeared, leading to a decline in use of the drugs by many patients who would benefit from the treatment. While patient characteristics have contributed to improved understanding of risk factors, the mechanisms involved that explain AFF risk have not appeared. Recently, the possibility that the mechanism(s) involved drug-induced modification of cells of the nutrient canals of the femur and subsequent compromise in the bone matrix has been published. The present Hypothesis article builds on the concept presented earlier and expands into biomechanical considerations. An analogy of the mechanisms involved to a real-life scenario is also presented. While this analogy has limitations, consideration of the biomechanical implications of progressive alterations to defects presented by compromised nutrient canal-bone matrix also presents potential relationships with AFF risk.

Repair of osteochondral defects: efficacy of a tissue-engineered hybrid implant containing both human MSC and human iPSC-cartilaginous particles.

Both mesenchymal stromal cells (MSC) and induced pluripotent stem cells (iPSC) offer the potential for repair of damaged connective tissues. The use of hybrid implants containing both human MSC and iPSC was investigated to assess their combined potential to yield enhanced repair of osteochondral defects. Human iPSC-CP wrapped with tissue engineered constructs (TEC) containing human MSC attained secure defect filling with good integration to adjacent tissue in a rat osteochondral injury model. The presence of living MSC in the hybrid implants was required for effective biphasic osteochondral repair. Thus, the TEC component of such hybrid implants serves several critical functions including, adhesion to the defect site via the matrix and facilitation of the repair via live MSC, as well as enhanced angiogenesis and neovascularization. Based on these encouraging studies, such hybrid implants may offer an effective future intervention for repair of complex osteochondral defects.

Complement factor D regulates collagen type I expression and fibroblast migration to enhance human tendon repair and healing outcomes.

Introduction: Dense connective tissues (DCTs) such as tendon, ligament, and cartilage are important stabilizers and force transmitters in the musculoskeletal system. The healing processes after DCT injuries are highly variable, often leading to degenerative changes and poor clinical outcome. Biomarkers in relation to repair quality for human DCTs, especially tendon are lacking. This study expands our previous findings and aimed to characterize the mechanisms by which a potential biomarker of good outcomes, complement factor D (CFD), regulates tendon healing. Methods: Quantitative mass spectrometry (QMS) profiling of tissue biopsies from the inflammatory phase of healing (n = 40 patients) and microdialysates from the proliferative phase of healing (n = 28 patients) were used to identify specific biomarkers for tendon healing. Further bioinformatic and experimental investigations based on primary fibroblasts and fibroblast cell line were used to confirm the identified biomarkers. Results: The QMS profiling of tissue biopsies from the inflammatory phase of healing identified 769 unique proteins, and microdialysates from the proliferative phase of healing identified 1423 unique proteins in Achilles tendon rupture patients. QMS-profiling showed that CFD expression was higher during the inflammatory- and lower during the proliferative healing phase in the good outcome patients. Further bioinformatic and experimental explorations based on both inflammatory and proliferative fibroblast models demonstrated that CFD potentially improved repair by regulating cell migration and modulating collagen type I (Col1a1) expression. Moreover, it was shown that the enhanced Col1a1 expression, through increased fibroblast migration, was correlated with the validated clinical outcome. Discussion: The results of the current studies characterized underlying inflammatory- and proliferative healing mechanisms by which CFD potentially improved tendon repair. These findings may lead to improved individualized treatment options, as well the development of effective therapies to promote good long-term clinical outcomes after tendon and other DCT injuries. Trial registration: http://clinicaltrials.gov, identifiers NCT02318472, NCT01317160.

Five-Year Outcomes After Implantation of a Scaffold-Free Tissue-Engineered Construct Generated From Autologous Synovial Mesenchymal Stromal Cells for Repair of Knee Chondral Lesions.

Background: In an earlier study, a scaffold-free tissue-engineered construct (TEC) derived from autologous synovial membrane mesenchymal stromal cells (MSCs) was developed and demonstrated to be safe and effective for cartilage repair at 2 years postoperatively. Purpose: To investigate clinical outcomes and magnetic resonance imaging (MRI) findings at 5 years after implantation. Study Design: Case series; Level of evidence, 4. Methods: This was an observational first-in-human study limited to 5 patients (age, 28-46 years) with symptomatic knee chondral lesions (size, 1.5-3.0 cm2) on the medial femoral condyle, lateral femoral condyle, or femoral groove. Synovial MSCs were isolated from arthroscopic biopsy specimens and cultured to develop a TEC that matched the lesion size. The TECs were then implanted into chondral defects without fixation and assessed at up to 5 years postoperatively. The patients were clinically evaluated using the visual analog scale for pain, Lysholm score, Tegner score, and Knee injury and Osteoarthritis Outcome Score. An MRI scan evaluation was also performed for morphologic and compositional quality of the repair tissue at both 2 and 5 years of follow-up. Results: All clinical scores were significantly improved from the preoperative evaluation to the 2- and 5-year follow-ups and the results were stable over time. The MRI scan evaluation showed cartilage defects filled with newly generated tissues with good tissue integration to adjacent host cartilage over time. The cartilage thickness and surface smoothness of the repair cartilage were maintained up to 5 years postoperatively. The MOCART (magnetic resonance observation of cartilage repair tissue) 2.0 Knee Scores remained high at 5 years, although the total points decreased slightly. Conclusion: The results highlight the efficacy and feasibility of autologous scaffold-free TEC derived from synovial MSCs for regenerative cartilage repair via a sutureless and simple implantation procedure, showing good clinical outcomes and MRI findings with stable results at midterm follow-up. Further follow-up will be needed to assess the long-term quality of the repair tissue.

Implementing a guideline-based education and exercise program for people with knee and hip osteoarthritis-Practical experiences of providers and clinic leaders: A qualitative study.

BACKGROUND: The Good Life with osteoArthritis: Denmark (GLA:DTM ) program is an evidence-based education and exercise program designed for individuals with symptomatic hip and knee osteoarthritis. Launched in Denmark, it has been implemented across Europe, Australia, and North America. The authors assessed the feasibility of GLADTM implementation in Canada (Alberta) by applying the RE-AIM framework. An evaluation objective was to identify factors impacting the implementation of the program in both publicly funded and private rehabilitation settings, based on the experience of the initial cohort of providers and clinic leaders who set up and delivered the program. METHODS: Semi-structured telephone interviews were conducted with GLA:DTM -trained providers, managers, or directors of clinics across Alberta. Braun and Clarke's thematic approach was used to code the data and identify emergent categories and themes. Those relevant to the implementation were identified and by consensus, categorized as facilitators of and challenges to the implementation process. RESULTS: Eighteen GLA:DTM -trained providers and three clinic leaders from a range of clinical settings completed an interview. Seven common themes emerged in relation to implementation across the study settings. Three themes reflect facilitators of implementation (program acceptability by providers, multi-level support mechanisms, and program flexibility) and four implementation challenges (direct and indirect costs, lack of external referrals, program access issues, and lack of suitable space). The initial implementation of the program was exploratory with limited focus on long-term sustainability. CONCLUSIONS: The GLA:DTM program is a translatable program that can be implemented with relative ease in both public and private rehabilitation settings; however, costs, space constraints, and having an adequate referral base were noted challenges. Further work is warranted to explore equitable access across public and private settings and program sustainability.

Evaluation of Uveitis Induced in Rats by a Type I Collagen Peptide as a Model for Childhood Arthritis-associated Uveitis.

Chronic asymptomatic and acute symptomatic anterior uveitis are forms of ocular inflammation associated with juvenile idiopathic arthritis (JIA) Chronic JIA-associated uveitis is characterized by young age of onset, female predilection, oligoarthritis, and antinuclear antibody (ANA) positivity. Acute JIA-associated uveitis predominantly affects older male juveniles who also develop enthesitis. A type I collagen-derived peptide (melanin-associated antigen [MAA]) induces anterior uveitis in rodents. In this study, we evaluated MAA-induced uveitis in rats as a potential model for JIA-uveitis. We characterized MAA-induced uveitis by assessing its relationship to age and sex; tracking the occurrence of arthritis, enthesitis, and ANA positivity; and measuring vitreous fluid inflammatory biomarkers. Juvenile and adult and male and female Lewis rats (Rattus norvegicus) were inoculated with MAA. Slit-lamp biomicroscopy, indirect ophthalmoscopy, and joint examinations were performed 3 times weekly. Rats were euthanized at 4 wk after MAA inoculation, and plasma ANA testing, vitreous inflammatory biomarker assays, and globe histopathology assessments were conducted. Uveitis, arthritis, ANA status, levels of inflammatory biomarkers, histopathology, and joint tomographic images were assessed in relation to age and sex and compared with nonuveitic controls. All MAA-immunized rats developed uveitis characterized by anterior chamber fibrin, iridal vessel dilation, and miosis, and uveal and choroidal lymphocytic infiltration. Levels of the vitreous fluid biomarker CCL5 were higher in uveitic rats compared with control rats. Time to uveitis onset, clinical uveitis scores, and biomarker levels did not differ based on age or sex. None of the MAA-exposed rats had arthritis, enthesitis, or ANA. None of the rats inoculated with MAA that had been treated with matrix metallopeptidase 1 had clinical, histologic, or immunohistochemical evidence of ocular inflammation. In contrast to JIA-associated uveitis in humans, MAA-induced uveitis in rats is not associated with age or sex predilections and MAA is not arthritogenic.

The effect of geographic location and payor type on provincial-wide delivery of the GLA:D program for hip and knee osteoarthritis in Alberta, Canada.

Objective: The Good Life with osteoArthritis: Denmark (GLA:D™) program for knee and hip osteoarthritis has been shown to be effective, but evaluations have yet to explore whether effectiveness differs by program context. The present study explores whether there are differences in effectiveness of the GLA:D™ program for treatment of hip and knee osteoarthritis across program location (i.e., rural, urban, metro) and program payor (i.e., public, private) within Alberta, Canada. Design: The study population was adults with hip or knee osteoarthritis attending the 8-week GLA:D™ supervised exercise and education programme in Alberta between Sep 2017-Mar 2020. Outcomes of interest were joint-related pain and quality of life (HOOS/KOOS), health quality of life (EQ-5D-5L), and performance-based functional (30-s chair stand test; 40-m walk test) measures. Minimally clinically important changes were calculated for each outcome and ANOVA and chi-square tests were used to determine statistical significance by program location or payor. Results: Of the 1321 eligible participants, 974 (73.7%) completed the baseline questionnaire, about 50% of participants participated in a metro area and 60% paid privately for the program. There were no statistically significant differences in improvements of joint-related pain, joint-related quality of life, health-related quality of life, or performance-based functional measures by program location or program payor, except for participants who received the program in a publicly covered primary care clinic who experienced significantly larger improvements in joint-related pain. Conclusion: The implementation of the GLA:D™ program for the treatment of knee and hip osteoarthritis in Alberta is effective across a range of contexts.

Physiological oxygen conditions enhance the angiogenic properties of extracellular vesicles from human mesenchymal stem cells.

BACKGROUND: Following an ischemic injury to the brain, the induction of angiogenesis is critical to neurological recovery. The angiogenic benefits of mesenchymal stem cells (MSCs) have been attributed at least in part to the actions of extracellular vesicles (EVs) that they secrete. EVs are membrane-bound vesicles that contain various angiogenic biomolecules capable of eliciting therapeutic responses and are of relevance in cerebral applications due to their ability to cross the blood-brain barrier (BBB). Though MSCs are commonly cultured under oxygen levels present in injected air, when MSCs are cultured under physiologically relevant oxygen conditions (2-9% O2), they have been found to secrete higher amounts of survival and angiogenic factors. There is a need to determine the effects of MSC-EVs in models of cerebral angiogenesis and whether those from MSCs cultured under physiological oxygen provide greater functional effects. METHODS: Human adipose-derived MSCs were grown in clinically relevant serum-free medium and exposed to either headspace oxygen concentrations of 18.4% O2 (normoxic) or 3% O2 (physioxic). EVs were isolated from MSC cultures by differential ultracentrifugation and characterized by their size, concentration of EV specific markers, and their angiogenic protein content. Their functional angiogenic effects were evaluated in vitro by their induction of cerebral microvascular endothelial cell (CMEC) proliferation, tube formation, and angiogenic and tight junction gene expressions. RESULTS: Compared to normoxic conditions, culturing MSCs under physioxic conditions increased their expression of angiogenic genes SDF1 and VEGF, and subsequently elevated VEGF-A content in the EV fraction. MSC-EVs demonstrated an ability to induce CMEC angiogenesis by promoting tube formation, with the EV fraction from physioxic cultures having the greatest effect. The physioxic EV fraction further upregulated the expression of CMEC angiogenic genes FGF2, HIF1, VEGF and TGFB1, as well as genes (OCLN and TJP1) involved in BBB maintenance. CONCLUSIONS: EVs from physioxic MSC cultures hold promise in the generation of a cell-free therapy to induce angiogenesis. Their positive angiogenic effect on cerebral microvascular endothelial cells demonstrates that they may have utility in treating ischemic cerebral conditions, where the induction of angiogenesis is critical to improving recovery and neurological function.

Alterations in skeletal muscle morphology and mechanics in juvenile male Sprague Dawley rats exposed to a high-fat high-sucrose diet.

Although once a health concern largely considered in adults, the obesity epidemic is now prevalent in pediatric populations. While detrimental effects on skeletal muscle function have been seen in adulthood, the effects of obesity on skeletal muscle function in childhood is not clearly understood. The purpose of this study was to determine if the consumption of a high-fat high-sucrose (HFS) diet, starting in the post-weaning period, leads to changes in skeletal muscle morphology and mechanics after 14 weeks on the HFS diet. Eighteen 3-week-old male CD-Sprague Dawley rats were randomly assigned to a HFS (C-HFS, n = 10) or standard chow diet (C-CHOW, n = 8). Outcome measures included: weekly energy intake, activity levels, oxygen consumption, body mass, body composition, metabolic profile, serum protein levels, and medial gastrocnemius gene expression, morphology, and mechanics. The main findings from this study were that C-HFS rats: (1) had a greater body mass and percent body fat than control rats; (2) showed early signs of metabolic syndrome; (3) demonstrated potential impairment in muscle remodeling; (4) produced lower relative muscle force; and (5) had a shift in the force-length relationship, indicating that the medial gastrocnemius had shorter muscle fiber lengths compared to those of C-CHOW rats. Based on the results of this study, we conclude that exposure to a HFS diet led to increased body mass, body fat percentage, and early signs of metabolic syndrome, resulting in functional deficits in MG of childhood rats.

Network proteomic analysis identifies inter-alpha-trypsin inhibitor heavy chain 4 during early human Achilles tendon healing as a prognostic biomarker of good long-term outcomes.

The suboptimal or protracted regeneration of injured connective tissues often results in significant dysfunction, pain, and functional disability. Despite the prevalence of the condition, few studies have been conducted which focused on biomarkers or key molecules involved in processes governing healing outcomes. To gain insight into injured connective tissue repair, and using the Achilles tendon as a model system, we utilized quantitative proteomic and weighted co-expression network analysis of tissues acquired from Achilles tendon rupture (ATR) patients with different outcomes at 1-year postoperatively. Two modules were detected to be associated with prognosis. The initial analysis identified inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4) as a biomarker or hub protein positively associated with better healing outcomes. Additional analysis identified the beneficial role of ITIH4 in inflammation, cell viability, apoptosis, proliferation, wound healing, and for the synthesis of type I collagen in cultured fibroblasts. Functionally, the effects of ITIH4 were found to be mediated by peroxisome proliferator-activated receptor gamma (PPARγ) signaling pathways. Taken together, these findings suggest that ITIH4 plays an important role in processes of connective tissue repair and advocate for the potential of ITIH4 as a therapeutic target for injured connective tissue repair. Trial registration: http://clinicaltrials.gov, identifiers NCT02318472, NCT01317160.