ABSTRACT
OBJECTIVE: Few studies have explored whether the involvement of patients in shared decision-making (SDM) is beneficial to the management of systemic lupus erythematosus (SLE). Therefore, this study investigated the relationship between patient participation in SDM and their trust in physicians using data from the TRUMP2-SLE study. METHODS: Data regarding the nine-item Shared Decision-Making Questionnaire (SDM-Q-9 scores), Trust in Physician Scale (TIPS) scores, and Abbreviated Wake Forest Physician Trust Scale (A-WFPTS) scores for interpersonal trust in a physician and trust in the medical profession were collected from patients with SLE who visited the outpatient clinics of five facilities in Japan through a self-administered questionnaire. The relationships between these scores were analyzed by general linear models with cluster-robust variance. RESULTS: This study included 433 patients with SLE. The median baseline TIPS and A-WFPTS (attending physician version) scores were 82 (73-93) and 80 (70-95), respectively. A higher baseline SDM-Q-9 score was correlated with an increase in the TIPS score at 1 year (coefficient per 10-pt increase, 0.94 pt [95%CI 0.16-1.72]). A higher baseline SDM-Q-9 score was correlated with a higher A-WFPTS score for interpersonal trust (coefficient per 10-pt increase, 2.20 pt [1.44-2.96]). The baseline SDM-Q-9 score was also correlated with an increase in the general physician version of A-WFPTS score at 1 year (coefficient per 10-pt increase, 1.29 pt [0.41-2.18]). CONCLUSION: Engagement of patients with SLE in SDM elevates their trust in the attending physicians and healthcare providers, potentially enhancing doctor-patient relationships and overall healthcare trust.
ABSTRACT
OBJECTIVE: Differences in communication styles based on physicians' personality traits have been identified, particularly in primary care, and these physician-related factors can be important in building patient-physician trust. This study examined the effects of rheumatologists' personality traits on patients' trust in their attending rheumatologists. METHODS: This cross-sectional study included adult Japanese patients with systemic lupus erythematosus (SLE) at 5 academic medical centers between June 2020 and August 2021. The exposures were the Big 5 personality traits (ie, extraversion, agreeableness, openness, conscientiousness, and emotional stability) of attending rheumatologists using the Japanese version of the 10-Item Personality Inventory scale (1-7 points each). The outcome was the patients' trust in their attending rheumatologist using the Japanese version of the 5-item Wake Forest Physician Trust Scale (0-100 points). A general linear model was fitted. RESULTS: The study included 505 patients with a mean age of 46.8 years; 88.1% were women. Forty-three attending rheumatologists (mean age: 39.6 years; 23.3% female) were identified. After multivariable adjustment, higher extraversion and agreeableness were associated with higher trust (per 1-point increase, 3.76 points [95% CI 1.07-6.45] and 4.49 points [95% CI 1.74-7.24], respectively), and higher conscientiousness was associated with lower trust (per 1-point increase, -2.17 points [95% CI -3.31 to -1.03]). CONCLUSION: Whereas higher extraversion and agreeableness of attending rheumatologists led to higher patient trust in their rheumatologist, overly high conscientiousness may lead to lower trust resulting from the physicians' demand of responsibility and adherence to instructions from patients with SLE.
Subject(s)
Lupus Erythematosus, Systemic , Rheumatologists , Adult , Humans , Female , Middle Aged , Male , Trust , Cross-Sectional Studies , PersonalityABSTRACT
Objectives: Infection is a leading cause of death in patients with systemic lupus erythematosus (SLE). Alt hough hydroxychloroquine (HCQ) has been reported to inhibit infection, evidence from Asian populations remains insufficient. We investigated this effect in Japanese SLE patients. Methods: Data from the Lupus Registry of Nationwide Institutions were used in this study. The patients were ≥20 years old and met the American College of Rheumatology (ACR) classification criteria revised in 1997. We defined "severe infections" as those requiring hospitalization. We analyzed the HCQ's effect on infection suppression using a generalized estimating equation (GEE) logistic regression model as the primary endpoint and performed a survival analysis for the duration until the first severe infection. Results: Data from 925 patients were used (median age, 45 [interquartile range 35-57] years; female, 88.1%). GEE analysis revealed that severe infections were significantly associated with glucocorticoid dose (odds ratio [OR] 1.968 [95% confidence interval, 1.379-2.810], p<0.001), immunosuppressants (OR 1.561 [1.025-2.380], p=0.038), and baseline age (OR 1.043 [1.027-1.060], p<0.001). HCQ tended to suppress severe infections, although not significantly (OR 0.590 [0.329-1.058], p=0.077). Survival time analysis revealed a lower incidence of severe infections in the HCQ group than in the non-HCQ group (p<0.001). In a Cox proportional hazards model, baseline age (hazard ratio [HR] 1.029 [1.009-1.050], p=0.005) and HCQ (HR 0.322 [0.142-0.728], p=0.006) were significantly related to incidence. Conclusion: HCQ may help extend the time until the occurrence of infection complications and tends to decrease infection rates.
Subject(s)
Hydroxychloroquine , Lupus Erythematosus, Systemic , Humans , Female , Adult , Middle Aged , Young Adult , Hydroxychloroquine/therapeutic use , Lupus Erythematosus, Systemic/complications , Lupus Erythematosus, Systemic/drug therapy , Glucocorticoids , Hospitalization , RegistriesABSTRACT
OBJECTIVE: Providing appropriate health information to patients with systemic lupus erythematosus (SLE) is advantageous in the treatment decision-making process. We aimed to investigate how online health information-seeking behaviors affect shared decision-making (SDM) in patients with SLE. METHODS: This cross-sectional study included 464 patients with SLE from five institutions. The main exposure was time spent on the internet per day, divided into four categories (none, <1 h, 1- < 2 h, ≥2 h). Participants categorized their preferred first source of health information as physicians, the internet, or other media. The outcome was the degree of SDM measured via the 9-item Shared Decision-Making Questionnaire (SDM-Q-9). A general linear model was applied. RESULTS: Compared to no internet use, longer internet use was associated with a higher SDM-Q-9 score: <1 h, 6.9 points (95% confidence interval [CI] 0.32 to 13.6) and ≥2 h, 8.75 points, (95% CI 0.61 to 16.9). The SDM-Q-9 did not differ between the individuals who chose physicians and those who chose the Internet as their preferred first source of health information (-2.1 points, 95% CI -6.7 to 2.6). Individuals who chose other media had significantly lower SDM-Q-9 scores than those who chose physicians (-7.6 points, 95% CI -13.2 to -1.9). CONCLUSIONS: The present study suggests that SDM between physicians and patients is positively associated with online information-seeking behavior, with no negative influence associated with accessing the Internet before clinical consultations. Rheumatologists may need to introduce their patients to websites offering high-quality health information to establish a good physician-patient relationship for SDM.
Subject(s)
Decision Making , Lupus Erythematosus, Systemic , Humans , Cross-Sectional Studies , Information Seeking Behavior , Lupus Erythematosus, Systemic/therapy , Patient ParticipationABSTRACT
OBJECTIVES: There is a high prevalence of burnout among rheumatologists. Grit, which is defined as possessing perseverance and a passion to achieve long-term goals, is predictive of success in many professions; however, whether grit is associated with burnout remains unclear, especially among academic rheumatologists, who have multiple simultaneous responsibilities. Thus, the purpose of this study was to examine the associations between grit and self-reported burnout components-professional efficacy, exhaustion, and cynicism-in academic rheumatologists. METHODS: This cross-sectional study involved 51 rheumatologists from 5 university hospitals. The exposure was grit, measured using mean scores for the 8-item Short Grit Scale (range, 1-5 [5 = extremely high grit]). The outcome measures were mean scores for 3 burnout domains (exhaustion, professional efficacy, and cynicism; range, 1-6; measured using the 16-item Maslach Burnout Inventory-General Survey). General linear models were fitted with covariates (age, sex, job title [assistant professor or higher vs lower], marital status, and having children). RESULTS: Overall, 51 physicians (median age, 45 years; interquartile range, 36-57; 76% men) were included. Burnout positivity was found in 68.6% of participants (n = 35/51; 95% confidence interval [CI], 54.1, 80.9). Higher grit was associated with higher professional efficacy (per 1-point increase; 0.51 point; 95% CI, 0.18, 0.84) but not with exhaustion or cynicism. Being male and having children were associated with lower exhaustion (-0.69; 95% CI, -1.28, -0.10; p = 0.02; and -0.85; 95% CI, -1.46, -0.24; p = 0.006). Lower job title (fellow or part-time lecturer) was associated with higher cynicism (0.90; 95% CI, 0.04, 1.75; p = 0.04). CONCLUSIONS: Grit is associated with higher professional efficacy among academic rheumatologists. To prevent burnout among staff, supervisors who manage academic rheumatologists should assess their staff's individual grit.
Subject(s)
Burnout, Professional , Lupus Erythematosus, Systemic , Physicians , Child , Humans , Male , Middle Aged , Female , Rheumatologists , Cross-Sectional Studies , Burnout, Professional/epidemiology , Surveys and QuestionnairesABSTRACT
OBJECTIVE: Poor medication adherence among patients with SLE is a critical problem associated with adverse outcomes. This study examined the relationship between trust in one's physician and goal-oriented thinking, hope and medication adherence among Japanese patients with SLE who were ethnically matched to their physicians. METHODS: This cross-sectional study was conducted in the rheumatology outpatient clinics at five academic centres. Patients with SLE who were prescribed oral medications were included. The main exposures were trust in one's physician measured via the 5-item Japanese version of the Wake Forest Physician Trust Scale and the 18-item Health-related Hope Scale, with each score ranging from 0 to 100 points. Medication adherence was measured using the 12-item Medication Adherence Scale with scores ranging from 5 to 60 points. A general linear model was created after adjusting for demographics, socioeconomic status, disease activity, disease duration, basic health literacy, depression, medication variables, experiencing adverse effects and concerns regarding lupus medications. RESULTS: Altogether, 373 patients with SLE were included. The mean age of the patients was 46.4 years; among them, 329 (88.2%) were women. Both trust in one's physician (per 10-point increase: 0.86, 95% CI 0.49, 1.22) and the Health-related Hope score (per 10-point increase: 0.66, 95% CI 0.35, 0.97) were associated with better medication adherence. CONCLUSIONS: This study demonstrated that patients' health-related hope and trust in their rheumatologist were both associated with better medication adherence in SLE.
Subject(s)
East Asian People , Lupus Erythematosus, Systemic , Medication Adherence , Physician-Patient Relations , Rheumatologists , Female , Humans , Male , Middle Aged , Cross-Sectional Studies , East Asian People/psychology , Lupus Erythematosus, Systemic/drug therapy , Lupus Erythematosus, Systemic/ethnology , Lupus Erythematosus, Systemic/psychology , Medication Adherence/ethnology , Medication Adherence/psychology , Trust , Hope , Goals , Thinking , Ambulatory Care FacilitiesABSTRACT
OBJECTIVES: Although personality characteristics of patients with SLE affect their disease activity and damage, it is unclear whether those of attending physicians affect the outcomes of patients with SLE. Grit is a personality trait for achieving long-term goals that may influence the decision-making for continuing treatment plans for patients. We aimed to evaluate the relationship between the grit of attending physicians and achievement of treatment goals in patients with SLE. METHODS: This cross-sectional study was conducted at five referral hospitals. The main exposure was 'consistency of interest' and 'perseverance of effort' of the attending physicians, measured by the Short Grit Scale. The primary outcome was achievement of a lupus low disease activity state (LLDAS). The association between physicians' grit score and LLDAS was analysed by generalized estimating equation (GEE) logistic regression with cluster robust variance estimation, with adjustment for confounders. RESULTS: The median (interquartile range) total, consistency and perseverance scores of 37 physicians were 3.1 (2.9-3.6), 3.3 (2.8-3.8) and 3.3 (3.0-3.5), respectively. Among the 386 patients, 154 (40%) had achieved LLDAS. Low consistency score (≤2.75) in physicians was related to LLDAS achievement independently using GEE logistic regression. The score of the question 'I often set a goal but later choose to pursue a different one' was significantly higher in patients achieving LLDAS. CONCLUSIONS: Difficulty of attending physicians to change treatment goals might be related to lower LLDAS achievement in patients with SLE.
Subject(s)
Lupus Erythematosus, Systemic , Physicians , Humans , Goals , Cross-Sectional Studies , Lupus Erythematosus, Systemic/therapy , Personality , Severity of Illness IndexABSTRACT
OBJECTIVE: Patients who trust their physicians have been shown to demonstrate good medication adherence, self-management, and favorable disease outcomes. This study examines how trust in physicians is affected by functional health literacy (HL) and by broader concepts of HL, including communicative HL and critical HL, among patients with systemic lupus erythematosus (SLE). METHODS: This was a cross-sectional study using baseline data from the Trust Measurement for Physicians and Patients with SLE (TRUMP2-SLE) study, an ongoing multicenter cohort study conducted at 5 academic centers. The 14-item Functional, Communicative, and Critical Health Literacy Scale assessed the 3 dimensions of HL; each item of the scale was scored on a 4-point Likert scale, ranging from 1 to 4. Outcomes were trust in one's physician and trust in physicians in general using the 5-item Wake Forest Physician Trust Scale, which ranged from 0 to 100 points. General linear models were fit. RESULTS: A total of 362 patients with SLE were included. Trust in one's physician increased with higher functional and communicative HL (per 1-point increase: mean difference 3.39, 95% CI 0.39-6.39, and mean difference 5.88, 95% CI 2.04-9.71, respectively). Trust in physicians in general increased with higher communicative HL and decreased with higher critical HL (per 1-point increase: mean difference 7.09, 95% CI 2.34-11.83, and mean difference -6.88, 95% CI -11.72 to -2.04, respectively). Longer internet use was associated with both higher communicative and critical HL. CONCLUSION: The findings suggest that rheumatologists need to improve their communication to match each patient's HL, which may foster trust and lead to improved self-management and outcomes in SLE. They also suggest that the formation of the rheumatologist-patient relationship may negate the effect of high critical HL in building trust.
Subject(s)
Health Literacy , Lupus Erythematosus, Systemic , Physicians , Humans , Trust , Cross-Sectional Studies , Cohort Studies , CommunicationABSTRACT
Disseminated nontuberculous mycobacterial infection (DNTM) is typically observed in immunocompromised hosts. Recently, it has been reported that healthy individuals with serum neutralizing autoantibodies for interferon (IFN)-γ can also develop DNTM. We herein report a case of anti-IFN-γ antibody-seropositive DNTM caused by Mycobacterium kansasii with symptoms mimicking TAFRO or POEMS syndrome, including anasarca, organomegaly, skin pigmentation, polyneuropathy, osteosclerotic change, thrombocytopenia, serum M protein, high C-reactive protein level, and reticulin fibrosis. The combination of antimicrobial chemotherapy with glucocorticoid and intravenous immunoglobulin improved his symptoms. Glucocorticoids may be an effective method of suppressing the production of anti-IFN-γ antibodies in DNTM.
Subject(s)
Castleman Disease , Mycobacterium Infections, Nontuberculous , Opportunistic Infections , Autoantibodies , Humans , Interferon-gamma , Mycobacterium Infections, Nontuberculous/diagnosis , Mycobacterium Infections, Nontuberculous/drug therapyABSTRACT
BACKGROUND: TRIM21 is a member of the tripartite motif family proteins and is one of the autoantigens which react with anti-SS-A antibody (Ab) present in sera of patients with systemic lupus erythematosus (SLE) and Sjögren's syndrome. Previous studies have shown that TRIM21 dysfunction promotes aberrant B-cell differentiation and Ab production in SLE, and anti-TRIM21 Ab may be related to the TRIM21 dysfunction in human SLE pathogenesis. Here, we examined the relationship between anti-TRIM21 Ab and clinical and immunological characteristics in SLE patients. METHODS: Twenty-seven patients with SLE (23 women and four men) before immunosuppressive therapies, who fulfilled the revised 1997 American College of Rheumatology criteria for SLE, and four healthy controls (3 women and one man) were enrolled in the study. SLE patients were divided into two groups according to the seropositivity for anti-TRIM21 Ab. Serum anti-TRIM21 Ab levels were measured using enzyme-linked immunosorbent assays. The serum levels of cytokines and immunoglobulins were measured by cytometer beads arrays. The expression levels of TRIM21 protein in peripheral mononuclear cells (PBMCs) from SLE patients were evaluated by Western blotting. RESULTS: Sixteen and 9 patients showed seronegativity and seropositivity for anti-TRIM21 Ab, respectively. There were no significant differences in the background parameters, including female ratio, age, disease duration, SLE activity, and laboratory data between the two groups. The serum levels of interferon (IFN)-ß were significantly higher in patients with anti-TRIM21 Ab as compared with those without anti-TRIM21 Ab (P = .043). The levels of IgG1 and IgA were significantly higher in SLE patients with anti-TRIM21 Ab as compared with those without anti-TRIM21 Ab (P = .0022 and .032, respectively). The PBMCs of patients with anti-TRIM21 Ab showed a significantly lower expression of TRIM21 protein as compared with those of patients without anti-TRIM21 Ab (P = .014). CONCLUSIONS: Anti-TRIM21 Ab seropositivity was related to B-cell abnormalities and type I IFN overproduction in SLE patients. These findings suggest that anti-TRIM21 Ab may have an inhibitory effect on TRIM21 functions and be a novel biomarker for the level of dependence on type I IFN overproduction and B-cell abnormalities.
Subject(s)
Interferon Type I , Lupus Erythematosus, Systemic , Sjogren's Syndrome , Autoantigens , B-Lymphocytes , Female , Humans , MaleABSTRACT
Cell polarity is essential for various asymmetric cellular events, and the partitioning defective (PAR) protein PAR3 (encoded by PARD3 in mammals) plays a unique role as a cellular landmark to establish polarity. In epithelial cells, PAR3 localizes at the subapical border, such as the tight junction in vertebrates, and functions as an apical determinant. Although we know a great deal about the regulators of PAR3 localization, how PAR3 is concentrated and localized to a specific membrane domain remains an important question to be clarified. In this study, we demonstrate that ASPP2 (also known as TP53BP2), which controls PAR3 localization, links PAR3 and protein phosphatase 1 (PP1). The ASPP2-PP1 complex dephosphorylates a novel phosphorylation site, Ser852, of PAR3. Furthermore, Ser852- or Ser889-unphosphorylatable PAR3 mutants form protein clusters, and ectopically localize to the lateral membrane. Concomitance of clustering and ectopic localization suggests that PAR3 localization is a consequence of local clustering. We also demonstrate that unphosphorylatable forms of PAR3 exhibited a low molecular turnover and failed to coordinate rapid reconstruction of the tight junction, supporting that both the phosphorylated and dephosphorylated states are essential for the functional integrity of PAR3.
Subject(s)
Cell Polarity , Protein Kinase C , Animals , Cell Cycle Proteins/metabolism , Cluster Analysis , Phosphorylation , Protein Kinase C/metabolism , Tight Junctions/metabolismABSTRACT
Optic perineuritis (OPN), which is an inflammatory disorder affecting the optic nerve sheath, is one of the rare complications in granulomatosis with polyangiitis (GPA). Although several groups have reported that immunosuppressive therapies are generally effective against GPA-associated OPN, so far, there is little information as to other options for refractory cases. Here we demonstrate a case of GPA-associated OPN, which is refractory to potent immunosuppressive therapy including high-dose glucocorticoid, intravenous cyclophosphamide and rituximab therapy, and effective application of therapeutic plasma exchange. We also report here that CSF IL-6 levels may serve as a new biomarker for GPA-associated OPN.
Subject(s)
Granulomatosis with Polyangiitis/complications , Immunosuppressive Agents/administration & dosage , Optic Neuritis/etiology , Optic Neuritis/therapy , Plasma Exchange , Biomarkers , Combined Modality Therapy , Granulomatosis with Polyangiitis/cerebrospinal fluid , Humans , Interleukin-6/cerebrospinal fluid , Optic Neuritis/cerebrospinal fluid , Optic Neuritis/diagnosis , Plasma Exchange/methods , Recurrence , Treatment OutcomeABSTRACT
TRIM21 is one of the autoantigens that reacts with an anti-SS-A antibody (Ab) present in patients with systemic lupus erythematosus (SLE) and Sjögren's syndrome. TRIM21 is thought to play a role in B-cell proliferation and apoptosis, among other activities. Here we examined a pathological role of TRIM21 in SLE. Trim21-deficient MRL/lpr mice were generated by backcrossing Trim21-deficient C57BL/6 mice to MRL/lpr mice. The levels of serum anti-dsDNA Ab and urine protein at 28 weeks of age were significantly higher in Trim21-deficient MRL/lpr mice as compared to wild-type MRL/lpr mice (p = 0.029 and 0.003, respectively). Resting B cells from Trim21-deficient mice showed significantly higher abilities to differentiate into plasmablasts and to produce Ab as compared with control mice. Due to the reduction of TRIM21-mediated ubiquitylation, IRF5 protein expression was increased in Trim21-deficient MRL/lpr mice (p = 0.021), which correlated with increased plasmablast generation and immunoglobulin production. B cells from SLE patients with anti-TRIM21 Ab seropositivity also showed a significantly higher ability to differentiate into plasmablasts as compared with those without anti-TRIM21 Ab or healthy controls. These results suggest that TRIM21 dysfunction contributes to SLE pathogenesis by promoting B-cell differentiation, for which anti-TRIM21 Ab may be partly responsible.
Subject(s)
Autoantigens/immunology , Autoimmunity/immunology , B-Lymphocytes/immunology , Cell Differentiation/immunology , Lupus Erythematosus, Systemic/immunology , Ribonucleoproteins/immunology , Adult , Animals , Autoantibodies/immunology , Female , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Inbred MRL lpr , Mice, KnockoutABSTRACT
AIM: To determine characteristics of rheumatoid arthritis (RA) patients in Japan who received the same biological disease-modifying antirheumatic drugs (bDMARDs) for at least 6 months and to identify factors associated with successful down-titration of bDMARDs dependent on shared decision-making. METHODS: We included consecutive RA patients who received the same bDMARD with low disease activity or remission for at least 6 months in our two university hospitals. Patients treated with the bDMARD standard dose were defined as SD, while those treated with bDMARD down-titration were defined as DT. We retrospectively reviewed clinical charts and compared data between the two groups. RESULTS: Of 288 patients with RA, 204 (70.8%) and 84 (29.2%) continued standard dose treatment and underwent down-titration treatment, respectively. Sixty-six of 84 (78.6%) down-titration-treated patients continued to show low disease activity or remission, whereas 18 (21.4%) relapsed 18.9 ± 24.4 months after bDMARD down-titration was started. Univariate predictor analysis showed that the probable factors of down-titration were no history of bDMARD treatment (P = .001) and low initial Disease Activity Assessment of 28 joint score (P = .048). Other clinical characteristics had no significant relationship with successful down-titration. CONCLUSIONS: Thus, bDMARD-naïve patients and those with low initial disease activity are more likely to agree to attempt down-titration. However, the timing and method of down-titration should be made in shared decision-making between patients and rheumatologists.
Subject(s)
Antirheumatic Agents/administration & dosage , Arthritis, Rheumatoid/drug therapy , Decision Making, Shared , Patient Participation , Patient Preference , Adult , Aged , Arthritis, Rheumatoid/diagnosis , Attitude of Health Personnel , Female , Health Knowledge, Attitudes, Practice , Hospitals, University , Humans , Japan , Male , Middle Aged , Recurrence , Remission Induction , Retrospective Studies , Rheumatologists/psychology , Severity of Illness Index , Time Factors , Treatment OutcomeABSTRACT
Circumferential actin belts underlying the adherens junctions of columnar epithelial cell monolayers control intercellular surface tension and cell shape to maintain tissue integrity. Yes-associated protein (YAP) and its paralog TAZ are proliferation-activating transcriptional coactivators that shuttle between the nucleus and cytoplasm. Previous studies suggest the importance of stress fibers in the actin cytoskeleton for regulation of YAP nuclear localization; however, the role of the circumferential actin belt on YAP localization remains unclarified. By manipulating actin tension, we demonstrate that circumferential actin belt tension suppresses YAP/TAZ nuclear localization. This suppression requires Merlin, an F-actin binding protein associated with adherens junctions. Merlin physically interacts with YAP/TAZ, and nuclear export sequences of Merlin are required for suppression. Together, with the observation that the association between E-cadherin and Merlin was diminished by tension in circumferential actin belts, our results suggest that released Merlin undergoes nucleocytoplasmic shutting and mediates export of YAP/TAZ from the nucleus.
Subject(s)
Actins/metabolism , Cell Nucleus/metabolism , Epithelial Cells/metabolism , Neurofibromin 2/metabolism , Nuclear Localization Signals , Transcription Factors/metabolism , Active Transport, Cell Nucleus , Animals , Caco-2 Cells , Cadherins/metabolism , Cell Line, Tumor , Cytoplasm/metabolism , Dogs , Humans , Madin Darby Canine Kidney Cells , Neurofibromin 2/chemistry , Protein BindingABSTRACT
Macrophages play crucial roles in host defence and tissue homoeostasis, processes in which both environmental stimuli and intracellularly generated metabolites influence activation of macrophages. Activated macrophages are classified into M1 and M2 macrophages. It remains unclear how intracellular nutrition sufficiency, especially for amino acid, influences on macrophage activation. Here we show that a lysosomal adaptor protein Lamtor1, which forms an amino-acid sensing complex with lysosomal vacuolar-type H+-ATPase (v-ATPase), and is the scaffold for amino acid-activated mTORC1 (mechanistic target of rapamycin complex 1), is critically required for M2 polarization. Lamtor1 deficiency, amino-acid starvation, or inhibition of v-ATPase and mTOR result in defective M2 polarization and enhanced M1 polarization. Furthermore, we identified liver X receptor (LXR) as the downstream target of Lamtor1 and mTORC1. Production of 25-hydroxycholesterol is dependent on Lamtor1 and mTORC1. Our findings demonstrate that Lamtor1 plays an essential role in M2 polarization, coupling immunity and metabolism.