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1.
JCI Insight ; 9(8)2024 Mar 19.
Article in English | MEDLINE | ID: mdl-38502232

ABSTRACT

Joint injury is associated with risk for development of osteoarthritis (OA). Increasing evidence suggests that activation of fibrinolysis is involved in OA pathogenesis. However, the role of the fibrinolytic pathway is not well understood. Here, we showed that the fibrinolytic pathway, which includes plasminogen/plasmin, tissue plasminogen activator, urokinase plasminogen activator (uPA), and the uPA receptor (uPAR), was dysregulated in human OA joints. Pharmacological inhibition of plasmin attenuated OA progression after a destabilization of the medial meniscus in a mouse model whereas genetic deficiency of plasmin activator inhibitor, or injection of plasmin, exacerbated OA. We detected increased uptake of uPA/uPAR in mouse OA joints by microPET/CT imaging. In vitro studies identified that plasmin promotes OA development through multiple mechanisms, including the degradation of lubricin and cartilage proteoglycans and induction of inflammatory and degradative mediators. We showed that uPA and uPAR produced inflammatory and degradative mediators by activating the PI3K, 3'-phosphoinositide-dependent kinase-1, AKT, and ERK signaling cascades and activated matrix metalloproteinases to degrade proteoglycan. Together, we demonstrated that fibrinolysis contributes to the development of OA through multiple mechanisms and suggested that therapeutic targeting of the fibrinolysis pathway can prevent or slow development of OA.


Subject(s)
Disease Models, Animal , Fibrinolysin , Fibrinolysis , Osteoarthritis , Receptors, Urokinase Plasminogen Activator , Urokinase-Type Plasminogen Activator , Animals , Mice , Humans , Fibrinolysin/metabolism , Osteoarthritis/metabolism , Osteoarthritis/pathology , Urokinase-Type Plasminogen Activator/metabolism , Receptors, Urokinase Plasminogen Activator/metabolism , Male , Female , Mice, Inbred C57BL , Plasminogen/metabolism , Signal Transduction , Mice, Knockout
2.
Arthritis Rheumatol ; 76(2): 181-191, 2024 02.
Article in English | MEDLINE | ID: mdl-37610274

ABSTRACT

OBJECTIVE: Anti-citrullinated protein antibodies (ACPAs) are highly specific for rheumatoid arthritis (RA) and have long been regarded as pathogenic. Despite substantial in vitro evidence supporting this claim, reports investigating the proinflammatory effects of ACPAs in animal models of arthritis are rare and include mixed results. Here, we sequenced the plasmablast antibody repertoire of a patient with RA and functionally characterized the encoded ACPAs. METHODS: We expressed ACPAs from the antibody repertoire of a patient with RA and characterized their autoantigen specificities on antigen arrays and enzyme-linked immunosorbent assays. Binding affinities were estimated by bio-layer interferometry. Select ACPAs (n = 9) were tested in the collagen antibody-induced arthritis (CAIA) mouse model to evaluate their effects on joint inflammation. RESULTS: Recombinant ACPAs bound preferentially and with high affinity (nanomolar range) to citrullinated (cit) autoantigens (primarily histones and fibrinogen) and to auto-cit peptidylarginine deiminase 4 (PAD4). ACPAs were grouped for in vivo testing based on their predominant cit-antigen specificities. Unexpectedly, injections of recombinant ACPAs significantly reduced paw thickness and arthritis severity in CAIA mice as compared with isotype-matched control antibodies (P ≤ 0.001). Bone erosion, synovitis, and cartilage damage were also significantly reduced (P ≤ 0.01). This amelioration of CAIA was observed for all the ACPAs tested and was independent of cit-PAD4 and cit-fibrinogen specificities. Furthermore, disease amelioration was more prominent when ACPAs were injected at earlier stages of CAIA than at later phases of the model. CONCLUSION: Recombinant patient-derived ACPAs ameliorated CAIA. Their antiinflammatory effects were more preventive than therapeutic. This study highlights a potential protective role for ACPAs in arthritis.


Subject(s)
Aminosalicylic Acids , Arthritis, Experimental , Arthritis, Rheumatoid , Humans , Animals , Mice , Anti-Citrullinated Protein Antibodies , Autoantibodies , Protein-Arginine Deiminases , Fibrinogen/metabolism , Collagen
3.
Evolution ; 77(12): 2642-2655, 2023 Dec 02.
Article in English | MEDLINE | ID: mdl-37738246

ABSTRACT

Selection varies between categories of individuals, with far-reaching ramifications: Sex-specific selection can impede or accelerate adaptation, and differences in selection between young and old individuals are ultimately responsible for senescence. Here, we measure early- and late-life fitness in adults of both sexes from the Drosophila genetic reference panel and perform quantitative genetic and transcriptomic analyses. Fitness was heritable, showed positive pleiotropy across sexes and age classes, and appeared to be influenced by very large numbers of loci with small effects plus a smaller number with moderate effects. Most loci affected male and female fitness in the same direction; relatively few candidate sexually antagonistic loci were found, though these were enriched on the X chromosome as predicted by theory. The expression level of many genes showed an opposite correlation with fitness in males and females, consistent with unresolved sexual conflict over transcription. The load of deleterious mutations correlated negatively with fitness across genotypes, and we found some evidence for the mutation accumulation (but not the antagonistic pleiotropy) theory of aging.


Subject(s)
Drosophila , Selection, Genetic , Humans , Animals , Male , Female , Drosophila/genetics , Transcriptome , Sexual Behavior , Genome , Drosophila melanogaster/genetics
4.
Sci Transl Med ; 15(684): eabq8476, 2023 02 22.
Article in English | MEDLINE | ID: mdl-36812347

ABSTRACT

Periodontal disease is more common in individuals with rheumatoid arthritis (RA) who have detectable anti-citrullinated protein antibodies (ACPAs), implicating oral mucosal inflammation in RA pathogenesis. Here, we performed paired analysis of human and bacterial transcriptomics in longitudinal blood samples from RA patients. We found that patients with RA and periodontal disease experienced repeated oral bacteremias associated with transcriptional signatures of ISG15+HLADRhi and CD48highS100A2pos monocytes, recently identified in inflamed RA synovia and blood of those with RA flares. The oral bacteria observed transiently in blood were broadly citrullinated in the mouth, and their in situ citrullinated epitopes were targeted by extensively somatically hypermutated ACPAs encoded by RA blood plasmablasts. Together, these results suggest that (i) periodontal disease results in repeated breaches of the oral mucosa that release citrullinated oral bacteria into circulation, which (ii) activate inflammatory monocyte subsets that are observed in inflamed RA synovia and blood of RA patients with flares and (iii) activate ACPA B cells, thereby promoting affinity maturation and epitope spreading to citrullinated human antigens.


Subject(s)
Arthritis, Rheumatoid , Periodontal Diseases , Humans , Autoantibodies , Mouth Mucosa , Antibody Formation , Epitopes , Bacteria
5.
Clin Immunol ; 244: 109117, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36109004

ABSTRACT

OBJECTIVE: Mast cells in the osteoarthritis (OA) synovium correlate with disease severity. This study aimed to further elucidate the role of mast cells in OA by RNA-Seq analysis and pharmacological blockade of the activity of histamine, a key mast cell mediator, in murine OA. METHODS: We examined OA synovial tissues and fluids by flow cytometry, immunostaining, single-cell and bulk RNA-Seq, qPCR, and ELISA. Cetirizine, a histamine H1 receptor (H1R) antagonist, was used to treat the destabilization of the medial meniscus (DMM) mouse model of OA. RESULTS: Flow cytometry and immunohistology analysis of OA synovial cells revealed KIT+ FcεRI+ and TPSAB1+ mast cells. Single-cell RNA-Seq of OA synovial cells identified the expression of prototypical mast cell markers KIT, TPSAB1, CPA3 and HDC, as well as distinctive markers HPGD, CAVIN2, IL1RL1, PRG2, and CKLF, confirmed by bulk RNA-Seq and qPCR. A mast cell prototypical marker expression score classified 40 OA patients into three synovial pathotypes: mast cell-high, -medium, and -low. Additionally, we detected mast cell mediators including histamine, tryptase AB1, CPA3, PRG2, CAVIN2, and CKLF in OA synovial fluids. Elevated H1R expression was detected in human OA synovium, and treatment of mice with the H1 receptor antagonist cetirizine reduced the severity and OA-related mediators in DMM. CONCLUSION: Based on differential expression of prototypical and distinct mast cell markers, human OA joints can be stratified into mast cell-high, -medium, and -low synovial tissue pathotypes. Pharmacologic blockade of histamine activity holds the potential to improve OA disease outcome.


Subject(s)
Arthritis, Rheumatoid , Osteoarthritis , Animals , Arthritis, Rheumatoid/metabolism , Cetirizine , Histamine/analysis , Histamine/metabolism , Histamine/pharmacology , Humans , Interleukin-1 Receptor-Like 1 Protein/metabolism , Mast Cells , Mice , Osteoarthritis/drug therapy , Osteoarthritis/genetics , Osteoarthritis/metabolism , RNA-Seq , Receptors, Histamine H1/metabolism , Synovial Membrane/metabolism , Tryptases/metabolism , Tryptases/pharmacology
6.
J Contin Educ Nurs ; 53(4): 165-170, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35357991

ABSTRACT

Background Although training can improve the quality of clinical teaching for nurse preceptors, research on the training needs of junior versus senior preceptors is limited. This study sought to examine the differences in their needs by comparing their clinical teaching experience and the training they received. Method A secondary analysis of a cross-sectional survey was conducted in three hospitals using the Clinical Teaching Behavior Inventory (CTBI). Survey data were analyzed using the chi-square test, the independent t test, and multiple regression analysis. Results The differences (N = 252) in the subscales of building a learning atmosphere and committing to teaching were not statistically significant (p > .05). Generally, the mean CTBI scores of trained junior preceptors were significantly higher than those of untrained senior preceptors (p < .001). Conclusion Training yields more significant improvements in self-perceived clinical teaching behavior than clinical teaching experience. [J Contin Educ Nurs. 2022;53(4):165-170.].


Subject(s)
Learning , Preceptorship , Cross-Sectional Studies , Humans , Preceptorship/methods , Surveys and Questionnaires
7.
J Allergy Clin Immunol ; 149(1): 358-368, 2022 01.
Article in English | MEDLINE | ID: mdl-33974929

ABSTRACT

BACKGROUND: IgG4-related disease (IgG4-RD) is a fibroinflammatory condition involving loss of B-cell tolerance and production of autoantibodies. However, the relevant targets and role of these aberrant humoral immune responses are not defined. OBJECTIVE: Our aim was to identify novel autoantibodies and autoantigen targets that promote pathogenic responses in IgG4-RD. METHODS: We sequenced plasmablast antibody repertoires in patients with IgG4-RD. Representative mAbs were expressed and their specificities characterized by using cytokine microarrays. The role of anti-IL-1 receptor antagonist (IL-1RA) autoantibodies was investigated by using in vitro assays. RESULTS: We identified strong reactivity against human IL-1RA by using a clonally expanded plasmablast-derived mAb from a patient with IgG4-RD. Plasma from patients with IgG4-RD exhibited elevated levels of reactivity against IL-1RA compared with plasma from the controls and neutralized IL-1RA activity, resulting in inflammatory and fibrotic mediator production in vitro. IL-1RA was detected in lesional tissues from patients with IgG4-RD. Patients with anti-IL-1RA autoantibodies of the IgG4 subclass had greater numbers of organs affected than did those without anti-IL-1RA autoantibodies. Peptide analyses identified IL-1RA epitopes targeted by anti-IL-1RA antibodies at sites near the IL-1RA/IL-1R interface. Serum from patients with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) also had elevated levels of anti-IL-1RA autoantibodies compared with those of the controls. CONCLUSION: A subset of patients with IgG4-RD have anti-IL-1RA autoantibodies, which promote proinflammatory and profibrotic meditator production via IL-1RA neutralization. These findings support a novel immunologic mechanism underlying the pathogenesis of IgG4-RD. Anti-IL-1RA autoantibodies are also present in a subset of patients with SLE and RA, suggesting a potential common pathway in multiple autoimmune diseases.


Subject(s)
Antibodies, Neutralizing/blood , Autoantibodies/blood , Fibrosis/immunology , Immunoglobulin G/immunology , Receptors, Interleukin-1/antagonists & inhibitors , Adolescent , Adult , Aged , Aged, 80 and over , Arthritis, Rheumatoid/blood , Arthritis, Rheumatoid/immunology , Autoantigens , Child , Child, Preschool , Female , Fibrosis/blood , Humans , Immunoglobulin G/blood , Lupus Erythematosus, Systemic/blood , Lupus Erythematosus, Systemic/immunology , Male , Middle Aged , Multiple Sclerosis/blood , Multiple Sclerosis/immunology , Receptors, Interleukin-1/immunology , Young Adult
8.
Clin Immunol ; 229: 108784, 2021 08.
Article in English | MEDLINE | ID: mdl-34126239

ABSTRACT

OBJECTIVE: Osteoarthritis (OA), the leading cause of joint failure, is characterized by breakdown of articular cartilage and remodeling of subchondral bone in synovial joints. Despite the high prevalence and debilitating effects of OA, no disease-modifying drugs exist. Increasing evidence, including genetic variants of the interleukin 4 (IL-4) and IL-4 receptor genes, implicates a role for IL-4 in OA, however, the mechanism underlying IL-4 function in OA remains unknown. Here, we investigated the role of IL-4 in OA pathogenesis. METHODS: Il4-, myeloid-specific-Il4ra-, and Stat6-deficient and control mice were subjected to destabilization of the medial meniscus to induce OA. Macrophages, osteoclasts, and synovial explants were stimulated with IL-4 in vitro, and their function and expression profiles characterized. RESULTS: Mice lacking IL-4, IL-4Ra in myeloid cells, or STAT6 developed exacerbated cartilage damage and osteophyte formation relative to WT controls. In vitro analyses revealed that IL-4 downregulates osteoarthritis-associated genes, enhances macrophage phagocytosis of cartilage debris, and inhibits osteoclast differentiation and activation via the type I receptor. CONCLUSION: Our findings demonstrate that IL-4 protects against osteoarthritis in a myeloid and STAT6-dependent manner. Further, IL-4 can promote an immunomodulatory microenvironment in which joint-resident macrophages polarize towards an M2 phenotype and efficiently clear pro-inflammatory debris, and osteoclasts maintain a homeostatic level of activity in subchondral bone. These findings support a role for IL-4 modulation of myeloid cell types in maintenance of joint health and identify a pathway that could provide therapeutic benefit for osteoarthritis.


Subject(s)
Interleukin-4/immunology , Macrophages/immunology , Osteoarthritis/prevention & control , Osteoclasts/immunology , Animals , Cartilage, Articular/immunology , Cartilage, Articular/pathology , Disease Models, Animal , Humans , Inflammation/immunology , Inflammation/pathology , Inflammation/prevention & control , Interleukin-4/deficiency , Interleukin-4/genetics , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Knockout , Osteoarthritis/immunology , Osteoarthritis/pathology , Osteoclasts/pathology , Phagocytosis , Receptors, Cell Surface/deficiency , Receptors, Cell Surface/genetics , Receptors, Cell Surface/immunology , STAT6 Transcription Factor/deficiency , STAT6 Transcription Factor/genetics , STAT6 Transcription Factor/immunology , Signal Transduction/immunology
9.
J Voice ; 35(4): 597-603, 2021 Jul.
Article in English | MEDLINE | ID: mdl-31911022

ABSTRACT

OBJECTIVE: To evaluate the prevalence of self-perceived voice problems and voice-related quality of life in a nontreatment seeking older population in Hong Kong. STUDY DESIGN: Prospective, cross-sectional survey. METHODS: One hundred and one older individuals aged 65 years or above were recruited from senior citizen community centers in Hong Kong. Each participant received a face-to-face interview with the researcher. The participants were asked to report the presence of voice problems and the voice symptoms that they experienced. They were also asked to complete the Cantonese version of the Voice Handicap Index to ascertain their voice-related quality of life. RESULTS: Over one-fourth (27.7%) of participants reported having current voice problems. Perceived voice problems were found to pose significant negative impacts on the older individuals' voice-related quality of life. The prevalence of voice problems and extent of impacts of voice-related quality of life were similar across the young-old, old-old, and the oldest-old groups of participants. CONCLUSION: The results suggest that voice problems are common in the older population and should not be underestimated. The study urges the need to allocate more resources to provide voice-related services from the young-old group for promoting positive aging.


Subject(s)
Quality of Life , Voice Disorders , Aged, 80 and over , Cross-Sectional Studies , Hong Kong/epidemiology , Humans , Prospective Studies , Surveys and Questionnaires , Voice Disorders/diagnosis , Voice Disorders/epidemiology
10.
Proc Biol Sci ; 287(1930): 20200575, 2020 07 08.
Article in English | MEDLINE | ID: mdl-32605521

ABSTRACT

Assuming that fathers never transmit mitochondrial DNA (mtDNA) to their offspring, mitochondrial mutations that affect male fitness are invisible to direct selection on males, leading to an accumulation of male-harming alleles in the mitochondrial genome (mother's curse). However, male phenotypes encoded by mtDNA can still undergo adaptation via kin selection provided that males interact with females carrying related mtDNA, such as their sisters. Here, using experiments with Drosophila melanogaster carrying standardized nuclear DNA but distinct mitochondrial DNA, we test whether the mitochondrial haplotype carried by interacting pairs of larvae affects survival to adulthood, as well as the fitness of the adults. Although mtDNA had no detectable direct or indirect genetic effect on larva-to-adult survival, the fitness of male and female adults was significantly affected by their own mtDNA and the mtDNA carried by their social partner in the larval stage. Thus, mtDNA mutations that alter the effect of male larvae on nearby female larvae (which often carry the same mutation, due to kinship) could theoretically respond to kin selection. We discuss the implications of our findings for the evolution of mitochondria and other maternally inherited endosymbionts.


Subject(s)
Mitochondria , Selection, Genetic , Animals , Drosophila melanogaster , Female , Haplotypes , Male , Maternal Inheritance , Siblings
11.
J Evol Biol ; 33(1): 89-100, 2020 01.
Article in English | MEDLINE | ID: mdl-31605400

ABSTRACT

Segregation distorters are selfish genetic elements that subvert Mendelian inheritance, often by destroying gametes that do not carry the distorter. Simple theoretical models predict that distorter alleles will either spread to fixation or stabilize at some high intermediate frequency. However, many distorters have substantially lower allele frequencies than predicted by simple models, suggesting that key sources of selection remain to be discovered. Here, we measured the fitness of Drosophila melanogaster adults and juveniles carrying zero, one or two copies of three different variants of the naturally occurring supergene Segregation Distorter (SD), in order to investigate why SD alleles remain relatively rare within populations despite being preferentially inherited. First, we show that the three SD variants differ in the severity and dominance of the fitness costs they impose on individuals carrying them. Second, SD-carrying parents produced less fit offspring in some crosses, independent of offspring genotype, indicating that SD alleles can have nongenetic, transgenerational costs in addition to their direct costs. Third, we found that SD carriers sometimes produce a biased offspring sex ratio, perhaps due to off-target effects of SD on the sex chromosomes. Finally, we used a theoretical model to investigate how sex ratio and transgenerational effects alter the population genetics of distorter alleles; accounting for these additional costs helps to explain why real-world segregation distorter alleles are rarer than predicted.


Subject(s)
Drosophila Proteins/genetics , Drosophila melanogaster/genetics , GTPase-Activating Proteins/genetics , Gene Dosage , Genetic Fitness/genetics , Models, Genetic , Animals , Female , Male , Sex Ratio
12.
J Evol Biol ; 33(2): 189-201, 2020 02.
Article in English | MEDLINE | ID: mdl-31650630

ABSTRACT

Maternal inheritance of mitochondrial DNA (mtDNA) was originally thought to prevent any response to selection on male phenotypic variation attributable to mtDNA, resulting in a male-biased mtDNA mutation load ("mother's curse"). However, the theory underpinning this claim implicitly assumes that a male's mtDNA has no effect on the fitness of females he comes into contact with. If such "mitochondrially encoded indirect genetics effects" (mtIGEs) do in fact exist, and there is relatedness between the mitochondrial genomes of interacting males and females, male mtDNA-encoded traits can undergo adaptation after all. We tested this possibility using strains of Drosophila melanogaster that differ in their mtDNA. Our experiments indicate that female fitness is influenced by the mtDNA carried by males that the females encounter, which could plausibly allow the mitochondrial genome to evolve via kin selection. We argue that mtIGEs are probably common, and that this might ameliorate or exacerbate mother's curse.


Subject(s)
Drosophila melanogaster/genetics , Genome, Mitochondrial/genetics , Maternal Inheritance , Animals , Female , Male , Selection, Genetic
13.
JCI Insight ; 4(18)2019 09 19.
Article in English | MEDLINE | ID: mdl-31534047

ABSTRACT

Osteoarthritis (OA) is the leading cause of joint failure, yet the underlying mechanisms remain elusive, and no approved therapies that slow progression exist. Dysregulated integrin function was previously implicated in OA pathogenesis. However, the roles of integrin αVß3 and the integrin-associated receptor CD47 in OA remain largely unknown. Here, transcriptomic and proteomic analyses of human and murine osteoarthritic tissues revealed dysregulated expression of αVß3, CD47, and their ligands. Using genetically deficient mice and pharmacologic inhibitors, we showed that αVß3, CD47, and the downstream signaling molecules Fyn and FAK are crucial to OA pathogenesis. MicroPET/CT imaging of a mouse model showed elevated ligand-binding capacities of integrin αVß3 and CD47 in osteoarthritic joints. Further, our in vitro studies demonstrated that chondrocyte breakdown products, derived from articular cartilage of individuals with OA, induced αVß3/CD47-dependent expression of inflammatory and degradative mediators, and revealed the downstream signaling network. Our findings identify a central role for dysregulated αVß3 and CD47 signaling in OA pathogenesis and suggest that activation of αVß3 and CD47 signaling in many articular cell types contributes to inflammation and joint destruction in OA. Thus, the data presented here provide a rationale for targeting αVß3, CD47, and their signaling pathways as a disease-modifying therapy.


Subject(s)
CD47 Antigen/metabolism , Cartilage, Articular/pathology , Integrin alphaVbeta3/metabolism , Osteoarthritis/immunology , Signal Transduction/immunology , Animals , CD47 Antigen/genetics , CD47 Antigen/immunology , Cartilage, Articular/cytology , Cartilage, Articular/diagnostic imaging , Cartilage, Articular/immunology , Cells, Cultured , Chondrocytes , Datasets as Topic , Disease Models, Animal , Disease Progression , Gene Expression Profiling , Humans , Integrin alphaVbeta3/genetics , Integrin alphaVbeta3/immunology , Male , Mice , Osteoarthritis/diagnostic imaging , Osteoarthritis/pathology , Positron Emission Tomography Computed Tomography , Primary Cell Culture , Proteomics , Synovial Membrane/cytology , Synovial Membrane/immunology , Synovial Membrane/pathology , Synoviocytes , X-Ray Microtomography
14.
Nurse Educ Pract ; 38: 112-119, 2019 Jul.
Article in English | MEDLINE | ID: mdl-31254943

ABSTRACT

Nurse preceptors play an important role in supporting newly qualified nurses during transition periods. However, limited attention is given to the needs and experience of nurse preceptors with expected responsibilities. This study aimed to examine the perceived needs of nurse preceptors in three public acute hospitals by using a sequential mixed method approach conducted between March and August 2017. A questionnaire that comprised socio-demographic data, Clinical Teaching Behaviour Inventory (CTBI), and RN Preceptor Learning Needs Assessment, was distributed to all nurse preceptors. Semi-structured qualitative interviews were conducted with a purposive sample of 10 informants to complement the quantitative findings. We received 260 completed questionnaires, giving a response rate of 78.8%. The highest mean CTBI domain score was "Using appropriate teaching strategies" (Mean = 3.65, SD = 0.56), whereas the lowest was "Providing feedback and evaluation" (Mean = 3.51, SD = 0.60). The top five topics identified as the most important in nurse preceptor training were critical thinking, prioritising, teaching techniques, conflict management and teamwork. Qualitative findings revealed that the informants experienced tension with their dual roles and strained relationships with co-workers. The expectations of the informants for support were recognition from management level and highlighting coaching tactics, reciprocal learning and collegiate support.


Subject(s)
Mentors/psychology , Needs Assessment , Preceptorship/methods , Adult , Attitude of Health Personnel , Cross-Sectional Studies , Female , Focus Groups/methods , Hong Kong , Hospitals , Humans , Male , Middle Aged , Qualitative Research , Surveys and Questionnaires
15.
Elife ; 82019 05 14.
Article in English | MEDLINE | ID: mdl-31084709

ABSTRACT

Osteoarthritis is characterized by articular cartilage breakdown, and emerging evidence suggests that dysregulated innate immunity is likely involved. Here, we performed proteomic, transcriptomic, and electron microscopic analyses to demonstrate that mast cells are aberrantly activated in human and murine osteoarthritic joint tissues. Using genetic models of mast cell deficiency, we demonstrate that lack of mast cells attenuates osteoarthritis in mice. Using genetic and pharmacologic approaches, we show that the IgE/FcεRI/Syk signaling axis is critical for the development of osteoarthritis. We find that mast cell-derived tryptase induces inflammation, chondrocyte apoptosis, and cartilage breakdown. Our findings demonstrate a central role for IgE-dependent mast cell activation in the pathogenesis of osteoarthritis, suggesting that targeting mast cells could provide therapeutic benefit in human osteoarthritis. Editorial note: This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that all the issues have been addressed (see decision letter).


Subject(s)
Cartilage/pathology , Immunoglobulin E/metabolism , Immunologic Factors/metabolism , Mast Cells/immunology , Osteoarthritis/pathology , Animals , Gene Expression Profiling , Humans , Mice , Microscopy, Electron , Proteomics , Signal Transduction
16.
Int Orthop ; 42(10): 2459-2466, 2018 10.
Article in English | MEDLINE | ID: mdl-29487990

ABSTRACT

PURPOSE: The mortality rate in patients with haemodynamically unstable pelvic fractures is as high as 40-60%. Despite the new advances in trauma care which are in phase in trauma centres in Hong Kong, the management of haemodynamically unstable pelvic fracture is still heterogeneous. The aim of this study is to review the results of management of haemodynamically unstable pelvic fracture patients in Hong Kong over a five year period. METHODS: This is a retrospective multi-centred cohort study of patients with haemodynamic and mechanically unstable pelvic fractures from 1 January 2010 to 31 December 2014. The primary outcome investigated is mortality of patients (including overall, 30-day, 7-day and 24-hour mortalities). RESULTS: Implementation of three-in-one pelvic damage control protocol was identified to be a significant independent predictive factor for overall, 30-day, seven-day and 24-hour mortalities. The overall in-hospital and 30-day mortality rates for patients managed with three-in-one protocol was 12.5%, while it was 11% for seven day mortality and 6% for 24 hour mortality. There were no significant differences in demographic characteristics, physiological measurements, types of pelvic fracture, severity and mechanism of injury between patients managed with or without three-in-one protocol. CONCLUSIONS: Implementation of the multidisciplinary three-in-one pelvic damage control protocol reduces mortality and therefore should be highly recommended. The results are convincing as it has eliminated the limitations of our previous single-centred trial.


Subject(s)
Fractures, Bone/mortality , Pelvic Bones/injuries , Adult , Angiography/methods , Cohort Studies , Female , Fracture Fixation/methods , Fractures, Bone/complications , Fractures, Bone/therapy , Hemodynamics , Hemostatic Techniques , Hong Kong , Hospital Mortality , Humans , Male , Middle Aged , Retrospective Studies , Survival Rate , Trauma Centers , Treatment Outcome , Young Adult
17.
Eur J Immunol ; 48(5): 874-884, 2018 05.
Article in English | MEDLINE | ID: mdl-29369345

ABSTRACT

Idiopathic pulmonary arterial hypertension (IPAH) is a devastating pulmonary vascular disease in which autoimmune and inflammatory phenomena are implicated. B cells and autoantibodies have been associated with IPAH and identified as potential therapeutic targets. However, the specific populations of B cells involved and their roles in disease pathogenesis are not clearly defined. We aimed to assess the levels of activated B cells (plasmablasts) in IPAH, and to characterize recombinant antibodies derived from these plasmablasts. Blood plasmablasts are elevated in IPAH, remain elevated over time, and produce IgA autoantibodies. Single-cell sequencing of plasmablasts in IPAH revealed repertoires of affinity-matured antibodies with small clonal expansions, consistent with an ongoing autoimmune response. Recombinant antibodies representative of these clonal lineages bound known autoantigen targets and displayed an unexpectedly high degree of polyreactivity. Representative IPAH plasmablast recombinant antibodies stimulated human umbilical vein endothelial cells to produce cytokines and overexpress the adhesion molecule ICAM-1. Together, our results demonstrate an ongoing adaptive autoimmune response involving IgA plasmablasts that produce anti-endothelial cell autoantibodies in IPAH. These antibodies stimulate endothelial cell production of cytokines and adhesion molecules, which may contribute to disease pathogenesis. These findings suggest a role for mucosally-driven autoimmunity and autoimmune injury in the pathogenesis of IPAH.


Subject(s)
Autoantibodies/immunology , Autoimmunity/immunology , Endothelial Cells/immunology , Familial Primary Pulmonary Hypertension/immunology , Plasma Cells/immunology , Antibody Formation/immunology , Cytokines/biosynthesis , Familial Primary Pulmonary Hypertension/blood , Familial Primary Pulmonary Hypertension/pathology , Female , Human Umbilical Vein Endothelial Cells/immunology , Humans , Intercellular Adhesion Molecule-1/biosynthesis , Lymphocyte Activation/immunology , Male , Middle Aged , Plasma Cells/cytology
18.
Asia Pac J Clin Oncol ; 14(2): e161-e166, 2018 Apr.
Article in English | MEDLINE | ID: mdl-28960862

ABSTRACT

AIM: Decisions regarding adjuvant chemotherapy for early breast cancer are complex. Ki67 is increasingly used, in conjunction with conventional prognostic markers, to help decide the use of adjuvant chemotherapy for early breast cancer. Ki67 has been proposed as an economical alternative to Oncotype DX recurrence score (RS), which is a validated prognostic marker for disease recurrence and predictive marker for benefit from chemotherapy. This study aimed to determine in patients where conventional prognostic markers did not provide a clear recommendation for adjuvant chemotherapy, whether Ki67 could be a substitute for RS. METHODS: We reviewed all cases of luminal-type node-negative early breast cancer (T1-2, N0-1mi, M0, estrogen receptor positive, HER2 negative) referred for Oncotype DX testing by the multidisciplinary team at an Australian tertiary private hospital from 14th December 2006 to 31st December 2013, when conventional prognostic markers did not provide a clear recommendation for adjuvant chemotherapy. RS was correlated with Ki67, along with other conventional prognostic markers including tumor size, grade, mitotic rate and lymphovascular invasion. Spearman's rank order correlation coefficient and Pearson product-moment correlation coefficient (r) were used for ordinal and continuous variables, respectively. RESULTS: A total of 58 patients were analyzed, median Ki67 was 15% (range 2-50%) and the median RS was 16 (range 3-65). There was no positive correlation between Ki67 and RS (r = 0.01, P = 0.93). No single conventional prognostic marker was shown to significantly correlate with RS, including tumor size (r = -0.02, P = 0.88), grade (r = 0.10, P = 0.44), mitotic rate (r = -0.07, P = 0.69) and lymphovascular invasion (r = -0.12, P = 0.39). CONCLUSION: Ki67 and conventional prognostic markers do not correlate with Oncotype DX RS. In the setting where conventional prognostic markers do not show a clear indication for or against adjuvant chemotherapy as determined by consensus in a multidisciplinary team, Ki67 is not a substitute for Oncotype DX testing. RS may provide additional information to aid decision making for adjuvant chemotherapy.


Subject(s)
Breast Neoplasms/genetics , Ki-67 Antigen/metabolism , Receptors, Estrogen/metabolism , Aged , Breast Neoplasms/pathology , Female , Humans , Middle Aged , Neoplasm Recurrence, Local/pathology , Prognosis , Retrospective Studies
19.
Asian J Neurosurg ; 12(1): 37-43, 2017.
Article in English | MEDLINE | ID: mdl-28413530

ABSTRACT

INTRODUCTION: The management of traumatic brain injuries in the elderly (age ≥ 65 years) is a constant dilemma. The aim of this study is to investigate for factors that may predict outcome of operative treatment in this group of patients. MATERIALS AND METHODS: A retrospective analysis was conducted on 68 elderly patients who had been operated in a designated center from 2006 to 2010. Patients' age, Glasgow Coma score (GCS), pupillary responses, imaging findings, medical conditions, and the use of anticoagulant/antiplatelet agents on patient outcomes were studied. RESULTS: The overall mortality rate was 55.9%. Older age, abnormal pupillary response, low GCS, the presence of midline shift and cistern obliteration on computerized tomography were associated with poor survival. Patient aged 75-84 with normal bilateral pupillary response still had an overall survival rate of 52.6% and good outcomes (Glasgow outcome score: 4 or 5) in 36.8% of patients. Abnormal pupillary response in at least one eye and preoperative GCS ≤ 12 were associated with very poor prognosis. CONCLUSIONS: More advanced age was found to be associated with progressively worse outcome. A subgroup patients aged below 85 would survive and could achieve good clinical outcome. The prognosis of those aged over 85 with moderate or severe head injuries was extremely poor.

20.
Ann Rheum Dis ; 76(5): 914-922, 2017 May.
Article in English | MEDLINE | ID: mdl-27965260

ABSTRACT

OBJECTIVES: While various monocyte chemokine systems are increased in expression in osteoarthritis (OA), the hierarchy of chemokines and chemokine receptors in mediating monocyte/macrophage recruitment to the OA joint remains poorly defined. Here, we investigated the relative contributions of the CCL2/CCR2 versus CCL5/CCR5 chemokine axes in OA pathogenesis. METHODS: Ccl2-, Ccr2-, Ccl5- and Ccr5-deficient and control mice were subjected to destabilisation of medial meniscus surgery to induce OA. The pharmacological utility of blocking CCL2/CCR2 signalling in mouse OA was investigated using bindarit, a CCL2 synthesis inhibitor, and RS-504393, a CCR2 antagonist. Levels of monocyte chemoattractants in synovial tissues and fluids from patients with joint injuries without OA and those with established OA were investigated using a combination of microarray analyses, multiplexed cytokine assays and immunostains. RESULTS: Mice lacking CCL2 or CCR2, but not CCL5 or CCR5, were protected against OA with a concomitant reduction in local monocyte/macrophage numbers in their joints. In synovial fluids from patients with OA, levels of CCR2 ligands (CCL2, CCL7 and CCL8) but not CCR5 ligands (CCL3, CCL4 and CCL5) were elevated. We found that CCR2+ cells are abundant in human OA synovium and that CCR2+ macrophages line, invade and are associated with the erosion of OA cartilage. Further, blockade of CCL2/CCR2 signalling markedly attenuated macrophage accumulation, synovitis and cartilage damage in mouse OA. CONCLUSIONS: Our findings demonstrate that monocytes recruited via CCL2/CCR2, rather than by CCL5/CCR5, propagate inflammation and tissue damage in OA. Selective targeting of the CCL2/CCR2 system represents a promising therapeutic approach for OA.


Subject(s)
Chemokines/genetics , Chemokines/metabolism , Macrophages , Monocytes/physiology , Osteoarthritis/metabolism , RNA, Messenger/metabolism , Animals , Cartilage, Articular/pathology , Chemokine CCL2/genetics , Chemokine CCL2/metabolism , Chemokine CCL5/genetics , Chemokine CCL5/metabolism , Chemotaxis , Fibroblasts/metabolism , Gene Expression , Humans , Indazoles/pharmacology , Leukocyte Count , Male , Mice, Inbred C57BL , Mice, Knockout , Osteoarthritis/pathology , Propionates/pharmacology , Receptors, CCR2/antagonists & inhibitors , Receptors, CCR2/genetics , Receptors, CCR2/metabolism , Receptors, CCR5/genetics , Receptors, CCR5/metabolism , Signal Transduction/drug effects , Synovial Fluid/metabolism
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