Systemic lupus erythematosus (SLE) is a rare autoimmune disease for which a population-based survey on the prevalence of the disease in South Korea has not yet been conducted. Our goal was to estimate the nationwide prevalence of SLE.
The International Classification of Diseases, Tenth Revision (ICD-10) code for SLE diagnosis—M32—was tentatively given when patients were suspected to have SLE before 2009. As such, the positive predictive value (PPV) of the M32 code shown in medical bills reflecting true SLE was uncertain. We attempted to estimate the prevalence of SLE in South Korea using national administrative database data from 2004–2006. We approximated the actual number of SLE patients by analyzing a list of SLE-coded patients provided by the National Health Insurance (NHI) and Health Insurance Review and Assessment Service. Prevalence was estimated by multiplying the PPV of the M32 diagnostic code by the number of patients receiving the code. The PPV was determined by three methods: direct investigation of the medical records of patients randomly selected from the SLE-coded patients list; assessment of all SLE patients treated at 56 selected hospitals in South Korea; and extrapolation from sub-groups at a single institute to the sub-groups of the national NHI data.
The estimated number of national SLE cases was between 9000 and 11 000, depending on the method of ascertainment, corresponding to a prevalence of 18.8–21.7 per 100 000 people.
This is the first report of a nationwide prevalence survey of SLE in South Korea. National databases may serve as a resource for epidemiologic studies of rare autoimmune diseases like SLE.
systemic lupus erythematosus; prevalence; epidemiology
Eupatilin is the main active component of DA-9601, an extract from Artemisia. Recently, eupatilin was reported to have anti-inflammatory properties. We investigated the anti-arthritic effect of eupatilin in a murine arthritis model and human rheumatoid synoviocytes. DA-9601 was injected into collagen-induced arthritis (CIA) mice. Arthritis score was regularly evaluated. Mouse monocytes were differentiated into osteoclasts when eupatilin was added simultaneously. Osteoclasts were stained with tartrate-resistant acid phosphatase and then manually counted. Rheumatoid synoviocytes were stimulated with TNF-α and then treated with eupatilin, and the levels of IL-6 and IL-1β mRNA expression in synoviocytes were measured by RT-PCR. Intraperitoneal injection of DA-9601 reduced arthritis scores in CIA mice. TNF-α treatment of synoviocytes increased the expression of IL-6 and IL-1β mRNAs, which was inhibited by eupatilin. Eupatilin decreased the number of osteoclasts in a concentration dependent manner. These findings, showing that eupatilin and DA-9601 inhibited the expression of inflammatory cytokines and the differentiation of osteoclasts, suggest that eupatilin and DA-9601 is a candidate anti-inflammatory agent.
Eupatilin; Arthritis, Experomental; Arthritis, Rheumatoid; DA-9601
Bone homeostasis, which involves formation and resorption, is an important process for maintaining adequate bone mass in humans. Rheumatoid arthritis (RA) is an autoimmune disease characterized by inflammation and bone loss, leading to joint destruction and deformity, and is a representative disease of disrupted bone homeostasis. The bone loss and joint destruction are mediated by immunological insults by proinflammatory cytokines and various immune cells. The connection between bone and immunity has been intensely studied and comprises the emerging field of osteoimmunology. Osteoimmunology is an interdisciplinary science investigating the interplay between the skeletal and the immune systems. The main contributors in osteoimmunology are the bone effector cells, such as osteoclasts or osteoblasts, and the immune cells, particularly lymphocytes and monocytes. Physiologically, osteoclasts originate from immune cells, and immune cells regulate osteoblasts and vice versa. Pathological conditions such as RA might affect these interactions, thereby altering bone homeostasis, resulting in the unfavorable outcome of bone destruction. In this review, we describe the osteoclastogenic roles of the proinflammatory cytokines and immune cells that are important in the pathophysiology of RA.
Induced pluripotent stem cells (iPSCs) were first described in 2006 and have since emerged as a promising cell source for clinical applications. The rapid progression in iPSC technology is still ongoing and directed toward increasing the efficacy of iPSC production and reducing the immunogenic and tumorigenic potential of these cells. Enormous efforts have been made to apply iPSC-based technology in the clinic, for drug screening approaches and cell replacement therapy. Moreover, disease modeling using patient-specific iPSCs continues to expand our knowledge regarding the pathophysiology and prospective treatment of rare disorders. Furthermore, autologous stem cell therapy with patient-specific iPSCs shows great propensity for the minimization of immune reactions and the provision of a limitless supply of cells for transplantation. In this review, we discuss the recent updates in iPSC technology and the use of iPSCs in disease modeling and regenerative medicine.
Induced pluripotent stem cells; Reprogramming technique; Gene editing; Disease model; Regenerative medicine
Bone destruction and inflammation are closely linked. Cytokines play an important role in inflammatory bone destruction by upregulating the receptor activator of nuclear factor-κB (NF-κB) ligand (RANKL). The direct role of cytokines that act in a non-RANKL-dependent manner has yet to be elucidated. The aim of this study was to investigate the direct osteoclastogenic properties of inflammatory cytokines at different time-points of osteoclastogenesis. Mouse bone marrow macrophages were stimulated with the macrophage colony-stimulating factor (M-CSF) and various concentrations of RANKL. Inflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-17 and IL-23, were added to the culture system of osteoclastogenesis. Two time-points of cytokine treatment were set. The ‘early’ effect of each cytokine was investigated at the time of first RANKL treatment, whereas the ‘late’ effect was investigated 48 h after the first RANKL challenge. Osteoclast differentiation and function were assessed using an osteoclast marker [tartrate-resistant acid phosphatase (TRAP)] and by visualization of pit formation. A permissive level of RANKL was required for cytokine-associated osteoclastogenesis in all experiments. In the M-CSF/RANKL monocellular culture system, IL-1β enhanced and IL-6 decreased osteoclast formation in a dose-dependent manner, regardless of temporal differences. Other cytokines showed various responses according to the phase of osteoclast maturation and the concentration of each cytokine and RANKL. Furthermore, luciferase assays showed that both IL-1β and RANKL activated the NF-κB signaling pathway. Collectively, our data revealed that targeting IL-1β may be a promising strategy to inhibit inflammation-associated bone destruction and osteoporosis.
inflammation; osteoclast; receptor activator nuclear factor-κB ligand; interleukin-1β; interleukin-6; nuclear factor-κB
We aimed to quantify periarticular osteoporosis and investigate its significance in 45 patients with rheumatoid arthritis (RA) and 106 controls. Dual-energy X-ray absorptiometry (DXA) was used to determine the ratio of shaft to periarticular bone mineral density (BMD) as an index of periarticular demineralization. Periarticular osteoporosis was measured by conventional radiography. The BMDs of shaft and periarticular regions in eight designated areas on proximal phalanges were quantified. Clinical variables were examined to identify risk factors for periarticular osteoporosis. The assessment of periarticular osteoporosis on X-ray images reached a moderate degree of interobserver agreement among four physicians (ĸ = 0.47). For BMD quantification, we designed three types of mathematical formulae: the ratio of shaft to periarticular BMD, the mean of the ratios, and the ratio of the sums. These ratios were significantly higher in the patients with early RA (disease duration ≤ 3 yr) than in controls (P < 0.01). The findings were not as distinctive in patients with established RA. Body mass index, cumulative dose of corticosteroid, and C-terminal telopeptide were correlated with BMD ratios. Conclusively, DXA-assisted localized quantification and BMD ratio calculations are feasible for assessing periarticular demineralization. Periarticular osteoporosis is a relatively distinctive feature of early RA.
Bone Density; Arthrits; Rheumatoid; Periarticular Osteopenia
Adipose-derived stem cells (ASCs) are mesenchymal stem cells (MSCs) derived from adipose tissue. MSCs have multiple properties including anti-inflammatory and immunomodulatory effects in various disease models and human diseases. However, the mechanisms underlying this wide range of effects need to be explored.
Collagen antibody-induced arthritis (CAIA) is a unique model in which arthritis is rapidly and strongly induced. ASCs were intraperitoneally infused into CAIA mice before or after arthritis induction. The serum levels of various cytokines, adipokines, and chemokines were measured. The expression of FC gamma receptors (FCGRs) was investigated in peritoneal macrophages ex vivo. RAW264.7 cells and ASCs were co-cultured to elucidate the direct and indirect role of ASCs on FCGR expression.
ASCs attenuated arthritis in CAIA mice. Serum levels of tumor necrosis factor α, interleukin (IL)-15, resistin, and leptin were reduced in ASC-treated CAIA mice, whereas serum levels of IL-6 and adiponectin were not affected. In peritoneal macrophages isolated from ASC-treated mice, expression of FCGRIIB, which is immunoinhibitory, was higher than that of FCGRI. Co-culture of ASCs with RAW264.7 cells modulated the expression of FCGRs. The expression patterns and timings of peak expression differed among FCGRs. Expression of FCGRIIB was higher and peaked earlier than that of FCGRI. FCGRIII expression was not affected by this co-culture.
This is a study to show that ASCs have anti-arthritic effects in CAIA mice. Modulation of FCGRs by ASCs might be a therapeutic mechanism in this antibody-associated arthritis model.
Adipose-derived stem cell; Mesenchymal stem cell; Collagen antibody-induced arthritis; FC gamma receptors
Allopurinol is a urate-lowering agent that is commonly used to prevent chemotherapy-related hyperuricemia. Allopurinol hypersensitivity syndrome (AHS) is a disorder involving multiple organs, which may be accompanied by cutaneous adverse reactions. We identified the characteristics and clinical outcomes of chemotherapy-associated AHS in patients with hematological malignancies.
This retrospective single-center study included 26 AHS patients (11 with and 15 without hematological malignancies) admitted to Seoul St. Mary's Hospital. AHS was defined using the criteria of Singer and Wallace. Comparisons were made using the Mann-Whitney U test and Fisher exact test as appropriate.
In patients with a hematological malignancy and AHS, statistically significant differences were observed in terms of younger age at onset; shorter duration of exposure; higher starting and maintenance doses of allopurinol; lower incidence of eosinophilia, leukocytosis, and underlying renal insufficiency; and more frequent occurrence of fever compared to AHS patients without a hematological malignancy. Two AHS patients with a hematological malignancy were examined for human leukocyte antigen (HLA)-B typing, but neither patient harbored the HLA-B*5801 allele. All of the patients ceased allopurinol treatment, with most patients making a full recovery. Two patients in the study died; however, these deaths were unrelated to AHS. One patient developed serious sequelae of AHS that required hemodialysis.
Physicians who prescribe allopurinol for the prevention of chemotherapy-related hyperuricemia should be aware of the unique risk of AHS, even in patients with hematological malignancies who do not have known risk factors for AHS. Novel urate-lowering agents should be considered alternative treatments.
Allopurinol hypersensitivity syndrome; Hematologic neoplasms
Gout is a chronic inflammatory disease the development of which is associated with obesity-induced metabolic abnormalities. However, a substantial number of non-obese patients (body mass index [BMI] <25 kg/m2) also develop gout in Korea. It was suggested that accumulation of visceral fat rather than subcutaneous fat is associated with metabolic abnormalities and hyperuricemia in patients with gout; therefore, we hypothesized that visceral fat accumulation was increased in non-obese gout patients.
One hundred and three male patients with primary gout and 204 age-matched healthy controls who attended a health check-up examination were recruited after the review of medical charts. The visceral fat area (VFA) was measured using the bioelectrical impedance analysis (BIA) method, and a VFA >100 cm2 was defined as visceral fat obesity (VFO). The frequency of VFO was compared in patients and control groups. The frequencies of metabolic syndrome and related parameters were also investigated.
BMI, waist circumference, total fat mass, serum triglycerides, and serum glucose levels were significantly greater in patients compared with controls. VFA and the prevalence of VFO was increased in gout patients compared with controls. There were positive correlations between VFA and serum triglyceride levels and serum glucose levels. Multivariate regression analysis revealed that VFO is an independent risk factor for gout (odds ratio 2.488, 95% confidence interval 1.041–4.435). In non-obese subgroup analyses (gout patients, n = 38; healthy controls, n = 150), VFA (98.7 ± 19.3 vs. 91.0 ± 16.7, P = 0.016) and the frequency of VFO (47.4 vs. 27.3%, P = 0.017) remained significantly higher in gout patients. There was no difference in either BMI or total fat mass between patients and controls in the non-obese subgroup. The prevalence of metabolic syndrome in patients with gout was 31.7% (33/104), compared with 13.2% (5/38) in the non-obese subgroup according to modified ATP III criteria.
VFO, measured using BIA, is observed more frequently in patients with primary gout compared with healthy controls, even in non-obese individuals. Therefore, VFO might more properly represent metabolic derangements in patients with gout than general obesity.
We investigated whether transthoracic echocardiography-suspected pulmonary hypertension (PH) affects survival in systemic lupus erythematosus (SLE) patients and examined factors associated with PH occurrence and survival.
This retrospective single-center study included 154 Korean SLE patients fulfilling the American College of Rheumatology criteria (January 1995 to June 2013). Student t test, Mann-Whitney U test, Kaplan-Meier curves, and log-rank tests were used for comparisons.
A total of 35 SLE patients with PH (SLE/PH+) and 119 without PH (SLE/PH-) were analyzed. Higher percentages of interstitial lung disease, Raynaud's phenomenon (RP), World Health Organization functional classification III/IV, and cardiomegaly were found in SLE/PH+ compared to SLE/PH-. Furthermore, the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index was significantly higher in SLE/PH+ (2.46 ± 1.245 vs. 1.00 ± 1.235), whereas survival rates were significantly higher in SLE/PH- in log-rank tests (p = 0.001). In multivariate analysis, the adjusted mortality hazard ratio (HR) for SLE/PH+ patients was 3.10. Subgroup analysis demonstrated a higher percentage of lupus nephritis in the SLE/PH+ patients who died (p = 0.039) and low complement-3 levels (p = 0.007). In univariate analysis, the mortality HR for SLE/PH+ patients with lupus nephritis was 4.62, whereas the presence of RP decreased the mortality risk in multivariate analysis; adjusted HR, 0.10.
PH is an independent factor predicting survival in SLE patients. The presence of lupus nephritis resulted in an increased trend for mortality, whereas coexistence of RP was associated with a better survival prognosis in SLE/PH+ patients.
Hypertension, pulmonary; Lupus erythematosus, systemic; Mortality; Survival rate
Biologics are the most successful drugs used in anticytokine therapy. However, they remain partially unsuccessful because of the elevated cost of their synthesis and purification. Development of novel biologics has also been hampered by the high cost. Biologics are made of protein components; thus, theoretically, they can be produced in vivo. Here we tried to invent a novel strategy to allow the production of synthetic drugs in vivo by the host itself. The recombinant minicircles encoding etanercept or tocilizumab, which are synthesized currently by pharmaceutical companies, were injected intravenously into animal models. Self-reproduced etanercept and tocilizumab were detected in the serum of mice. Moreover, arthritis subsided in mice that were injected with minicircle vectors carrying biologics. Self-reproducible biologics need neither factory facilities for drug production nor clinical processes, such as frequent drug injection. Although this novel strategy is in its very early conceptual stage, it seems to represent a potential alternative method for the delivery of biologics.
The aim of the current study is to identify patients without osteoporosis who met the criteria of the fracture risk assessment tool (FRAX) of the National Osteoporosis Foundation (NOF) only. The incidence of fractures was investigated in patients who met only the FRAX criteria of the NOF and patients who presented osteoporosis. Five hundred and forty five patients with rheumatoid arthritis who visited a single center were recruited in Korea. In the follow-up period of median 30 months, the new onset of fractures was investigated. Of 223 patients who have no osteoporosis, 39 (17.4%) satisfied the FRAX criteria for pharmacological intervention. During the follow-up period, 2 new onset fractures occurred in patients who met only the FRAX criteria and 22 new onset fractures did in patients with osteoporosis by bone mineral density. The incidence rate for new onset fractures of patients who met only the FRAX criteria was with 295.93 per 10,000 person-years higher than in the general population with 114.99 per 10,000 person-years. Patients who met the FRAX criteria of the NOF only need pharmacological intervention because their numbers of incidence for new onset fractures are similar to those of patients with osteoporosis by BMD.
Arthritis, Rheumatoid; Osteoporosis; Fractures, Bone; BMD; FRAX
Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic joint inflammation. Red ginseng is a steamed and dried Panax ginseng C.A. Meyer, which has been used as alternative medicine for thousands of years. This study was undertaken to investigate the effects of red ginseng extracts (RGE) on autoimmune arthritis in mice and humans and to delineate the underlying mechanism. RGE was orally administered three times a week to mice with arthritis. Oral administration of RGE markedly ameliorated clinical arthritis score and histologically assessed joint inflammation in mice with CIA. A significant reduction in STAT3 phosphorylation and a decrease in the number of Th17 cells were observed with RGE treatment. There was also a marked reduction in RANKL-induced osteoclastogenesis with treatment of RGE. The inhibitory effect of RGE on Th17 differentiation and osteoclastogenesis observed in mice was also confirmed in the subsequent experiments performed using human peripheral blood mononuclear cells. Our findings provide the first evidence that RGE can regulate Th17 and reciprocally promote Treg cells by inhibiting the phosphorylation of STAT3. Therefore, RGE can ameliorate arthritis in mice with CIA by targeting pathogenic Th17 and osteoclast differentiation, suggesting a novel therapy for treatment of RA.
Ankylosing spondylitis (AS) is associated with an increased incidence of vertebral fractures (VFs); however the actual incidence and predictors of morphometric VFs are unknown. The present study examined the incidence and predictors of new VFs in a large AS cohort.
In total, 298 AS patients who fulfilled the modified New York criteria were enrolled and spinal radiographs were evaluated biennially. Clinical and laboratory data and radiographic progression were assessed according to the Bath AS Disease Activity Index, erythrocyte sedimentation rate, C-reactive protein (CRP), and the Stoke AS spine score (SASSS). VF was defined according to the Genant criteria. The incidence of VFs at 2 and 4 years was evaluated using the Kaplan-Meier method. The age-specific standardized prevalence ratio (SPR) for AS patients in comparison with the general population was calculated.
Of 298 patients, 31 (10.8%) had previous VFs at baseline. A total of 30 new VFs occurred in 26 patients over 4 years. The incidence of morphometric VFs was 4.7% at 2 years and 13.6% at 4 years. Multivariate logistic regression analysis showed that previous VFs at baseline and increased CRP levels at 2 years were predictors of new VFs (odds ratio (OR) =12.8, 95% confidence interval (CI) = 3.6-45.3 and OR = 5.4, 95% CI = 1.4–15.9). The age-specific specific standardized prevalence ratio of morphometric VFs in AS was 3.3 (95% CI 2.1–4.5).
The incidence of morphometric VFs increased in AS. Previous VFs and increased CRP levels predicted future VFs. Further studies are needed to identify the effects of treatment interventions on the prevention of new VFs.
Since the concept of reprogramming mature somatic cells to generate induced pluripotent stem cells (iPSCs) was demonstrated in 2006, iPSCs have become a potential substitute for embryonic stem cells (ESCs) given their pluripotency and “stemness” characteristics, which resemble those of ESCs. We investigated to reprogram fibroblast-like synoviocytes (FLSs) from patients with rheumatoid arthritis (RA) and osteoarthritis (OA) to generate iPSCs using a 4-in-1 lentiviral vector system.
A 4-in-1 lentiviral vector containing Oct4, Sox2, Klf4, and c-Myc was transduced into RA and OA FLSs isolated from the synovia of two RA patients and two OA patients. Immunohistochemical staining and real-time PCR studies were performed to demonstrate the pluripotency of iPSCs. Chromosomal abnormalities were determined based on the karyotype. SCID-beige mice were injected with iPSCs and sacrificed to test for teratoma formation.
After 14 days of transduction using the 4-in-1 lentiviral vector, RA FLSs and OA FLSs were transformed into spherical shapes that resembled embryonic stem cell colonies. Colonies were picked and cultivated on matrigel plates to produce iPSC lines. Real-time PCR of RA and OA iPSCs detected positive markers of pluripotency. Immunohistochemical staining tests with Nanog, Oct4, Sox2, Tra-1-80, Tra-1-60, and SSEA-4 were also positive. Teratomas that comprised three compartments of ectoderm, mesoderm, and endoderm were formed at the injection sites of iPSCs. Established iPSCs were shown to be compatible by karyotyping. Finally, we confirmed that the patient-derived iPSCs were able to differentiate into osteoblast, which was shown by an osteoimage mineralization assay.
FLSs derived from RA and OA could be cell resources for iPSC reprogramming. Disease- and patient-specific iPSCs have the potential to be applied in clinical settings as source materials for molecular diagnosis and regenerative therapy.
There is no consensus on whether it is safe to re-administer tumor necrosis factor-alpha (TNFα) inhibitors in patients with rheumatoid arthritis (RA) or ankylosing spondylitis (AS) flared after withdrawal of TNFα inhibitors due to active tuberculosis (TB). We evaluated the safety of restarting anti-TNFα therapy in patients with TNFα-associated TB. We used data of 1,012 patients with RA or AS treated with TNFα inhibitors at Seoul St. Mary's Hospital between January 2003 and July 2013 to identify patients who developed active TB. Demographic and clinical data including the results of tuberculin skin tests (TST) and interferon-γ releasing assays (IGRA) were collected. Fifteen patients developed active TB. Five cases were occurred in RA and 10 cases in AS. Nine of 15 patients had a negative TST or IGRA and 6 TST-positive patients had received prophylaxis prior to initiating anti-TNFα therapy. All patients discontinued TNFα inhibitors with starting the treatment of TB. Eight patients were re-administered TNFα inhibitors due to disease flares and promptly improved without recurrence of TB. TNFα inhibitors could be safely resumed after starting anti-TB regimen in patients with RA or AS.
TNFα Inhibitor; Tuberculosis; Arthritis, Rheumatoid; Spondylitis, Ankylosing
Grape seed proanthocyanidin extract (GSPE) is a natural flavonoid that exerts anti-inflammatory properties. Obesity is an inflammatory condition and inflammatory cells and their secretion of pro-inflammatory molecules contribute to the pathogenesis of obesity. Rheumatoid arthritis (RA) is a chronic autoimmune disease that is characterized by inflammation of joints lined by synovium. Previously, we demonstrated that obesity augmented arthritis severity in collagen induced arthritis (CIA), a murine model of human RA. Here, we investigated whether oral administration of GSPE showed antiobesity and anti-arthritic effects in high-fat diet-induced obese (DIO) mice and in obese CIA mice, respectively. The pathophysiologic mechanisms by which GSPE attenuates weight gain and arthritis severity in vivo were also investigated. In DIO mice, GSPE administration significantly inhibited weight gain, reduced fat infiltration in liver and improved serum lipid profiles. The antiobesity effect of GSPE was associated with increased populations of regulatory T (Treg) cells and those of decreased Th17 cells. Decrease of Th17 cells was associated with significant inhibition of their key transcriptional factors, pSTAT3Tyr705 and pSTAT3Ser727. On the contrary, GSPE-induced Treg induction was associated with enhanced pSTAT5 expression. To identify the anti-arthritis effects of GSPE, GSPE was given orally for 7 weeks after type II collagen immunization. GSPE treatment significantly attenuated the development of autoimmune arthritis in obese CIA model. In line with DIO mice, GSPE administration decreased Th17 cells and reciprocally increased Treg cells by regulating STAT proteins in autoimmune arthritis model. The expressions of pro-inflammatory cytokines and nitrotyrosine in synovium were significantly inhibited by GSPE treatment. Taken together, GSPE functions as a reciprocal regulator of T cell differentiation – suppression of Th17 cells and induction of Tregs in both DIO and obese CIA mice. GSPE may act as a therapeutic agent to treat immunologic diseases related with enhanced STAT3 activity such as metabolic disorders and autoimmune diseases.
Varieties of transforming growth factor-β (TGF-β) antagonists have been developed to intervene with excessive TGF-β signalling activity in cancer. Activin receptor-like kinase5 (ALK5) inhibitors antagonize TGF-β signalling by blocking TGF-β receptor-activated Smad (R-Smad) phosphorylation. Here we report the novel mechanisms how ALK5 inhibitors exert a therapeutic effect on a mouse B16 melanoma model. Oral treatment with a novel ALK5 inhibitor, EW-7197 (2.5 mg/kg daily) or a representative ALK5 inhibitor, LY-2157299 (75 mg/kg bid) suppressed the progression of melanoma with enhanced cytotoxic T-lymphocyte (CTL) responses. Notably, ALK5 inhibitors not only blocked R-Smad phosphorylation, but also induced ubiquitin-mediated degradation of the common Smad, Smad4 mainly in CD8+ T cells in melanoma-bearing mice. Accordingly, T-cell-specific deletion of Smad4 was sufficient to suppress the progression of melanoma. We further identified eomesodermin (Eomes), the T-box transcription factor regulating CTL functions, as a specific target repressed by TGF-β via Smad4 and Smad3 in CD8+ T cells. Thus, ALK5 inhibition enhances anti-melanoma CTL responses through ubiquitin-mediated degradation of Smad4 in addition to the direct inhibitory effect on R-Smad phosphorylation.
ALK5 inhibitor; Eomes; melanoma; Smad4; TGF-β
The effects of several antihypertensive drugs on bone mineral density (BMD) and micro-architectural changes in ovariectomized (OVX) mice were investigated. Eight-week-old female C57/BL6 mice were used for this study. Three days after ovariectomy, mice were treated intraperitoneally with nifedipine (15 mg/kg), telmisartan (5 mg/kg), enalapril (20 mg/kg), propranolol (1 mg/kg) or hydrochlorothiazide (12.5 mg/kg) for 35 consecutive days. Uterine atrophy of all mice was confirmed to evaluate estrogen deficiency state. BMD and micro-architectural analyses were performed on tibial proximal ends by micro-computed tomography (micro-CT). When OVX mice with uterine atrophy were compared with mice without atrophy, BMD decreased (P < 0.001). There were significant differences in BMD loss between different antihypertensive drugs (P = 0.005). Enalapril and propranolol increased BMD loss in mice with atrophied uteri compared with control mice. By contrast, thiazide increased BMD in mice with uterine atrophy compared with vehicle-treated mice (P = 0.048). Thiazide (P = 0.032) and telmisartan (P = 0.051) reduced bone loss and bone fraction in mice with uterine atrophy compared with the control. Thiazide affects BMD in OVX mice positively. The reduction in bone loss by thiazide and telmisartan suggest that these drugs may benefit menopausal women with hypertension and osteoporosis.
Antihypertensive Agents; Osteoporosis; Ovariectomized Mice; Thiazides; Telmisartan
This study was conducted to determine whether CD4 T cell responses to citrullinated fibrinogen occur in patients with rheumatoid arthritis (RA), especially in HLA-DR4-positive subjects. Whole peripheral blood mononuclear cells (PBMCs) of RA patients and control subjects were stimulated with citrullinated fibrinogen peptides, and T-cell production of proliferation and proinflammatory cytokines, such as interferon-γ(IFN-γ) and interleukin-17A (IL-17A), were measured. In addition, CD4 T cells from RA patients were stimulated with the citrullinated fibrinogen peptide, Fib-α R84Cit, identified as a DRB1*0401-restricted T cell epitope in HLA-DR4 transgenic mice, and the degree of T cell activation was examined similarly. No proliferative responses to the citrullinated fibrinogen peptides were observed in whole PBMCs or CD4 T cells from RA patients. Furthermore, no increased production of IFN-γ or IL-17A was found in whole PBMCs or CD4 T cells stimulated with the citrullinated fibrinogen peptides, although these cells responded to recall antigen, a mixture of tetanus toxoid, purified protein derivative (PPD) from Mycobacterium tuberculosis, and Candida albicans. The results of this study indicate that anti-citrulline immunity in RA patients may be mediated by fibrinogen because there is no evidence of CD4 T cell-mediated immune responses to citrullinated fibrinogen peptides.
Rheumatoid arthritis (RA); Citrullinated fibrinogen (cFBG); CD4 T cell; HLA-DR4; Interferon-γ(IFN-γ); Interleukin-17A (IL-17A)
Fibroblast-like synoviocytes (FLSs) are a major cell population of the pannus that invades adjacent cartilage and bone in rheumatoid arthritis (RA). The study was undertaken to determine the effect of interleukin-17 (IL-17) on the survival and/or proliferation of FLSs from RA patients and to investigate whether signal tranducer and activator of transcription 3 (STAT3) is implicated in this process.
Bcl-2 and Bax expression in FLSs was determined using the real-time PCR and western blot analysis. The expression of Bcl-2 and phosphoSTAT3 in synovial tissues was investigated by confocal microscope. Apoptosis of FLSs was detected by Annexin V/propidium iodide staining and/or phase contrast microscopy. The proliferation of FLSs was determined by CCK-8 ELISA assay.
The pro-apoptotic Bax is decreased and anti-apoptotic Bcl-2 is increased in FLSs from RA patients compared with those from patients with osteoarthritis (OA). IL-17 upregulated the expression of Bcl-2 in FLSs from RA patients, but not in FLSs from OA patients. STAT3 was found to mediate IL-17-induced Bcl-2 upregulation in FLSs from RA patients. Additionally, IL-17 promoted the survival and proliferation of FLSs from RA patients. Most importantly, treatment with STAT3 inhibitor reversed the protective effect of IL-17 on FLSs apoptosis induced by sodium nitroprusside (SNP).
Our data demonstrate that STAT3 is critical in IL-17-induced survival of FLS from RA patients. Therefore, therapeutic strategies that target the IL-17/STAT3 pathway might be strong candidates for RA treatment modalities.