Seeking Treatment Profile of Male Shift Workers With Hypertension and Diabetes.

OBJECTIVE: This study was identified seeking treatment for hypertension and diabetes among male shift workers. METHOD: This retrospective cohort study included nine large companies in Japan. Data were collected from health checkup, health insurance records, and self-administered questionnaires in 2017 and 2020. Data were analyzed using Kaplan-Meier curves and Cox regression. RESULT: Person-days shift workers and day workers seeking treatment for hypertension were 41,604 and 327,301, respectively and, for diabetes, were 7326 and 60,735, respectively. The log ranks were statistically significant. Shift workers were 46% and 56% less likely to seek treatment for hypertension and diabetes, respectively, than day workers were after adjustment for age, marital status, education level, and intention to modify lifestyle (model 2) ( P < 0.01). CONCLUSIONS: Male shift workers are less likely to seek treatment for hypertension and diabetes compared with day workers.

High-frequency HbA1c testing among older patients with diabetes in Japan: a longitudinal analysis using medical claims data.

Aims: We aimed to determine the rate of high-frequency HbA1c testing among older Japanese patients (≥ 75 years) with type 2 diabetes who did not have diabetic complications and were not using insulin, and to explore its influencing factors and association with the number of hospital admissions. Methods: A retrospective, longitudinal observation study design based on medical claims data between 2015 and 2020 was adopted. We tracked patients for 3 years to describe the annual rate and determine factors associated with high-frequency HbA1c testing using a hierarchical logistical model. We employed a zero-inflated Poisson model to examine the association between frequency of HbA1c testing and the number of hospitalizations. Results: Among 6594 patients included (mean age 80.4 years), the rates of high-frequency HbA1c testing in the first, second, and third year were 10.2%, 4.8%, and 4.7%, respectively. Follow-up year [odds ratio (OR) = 0.54, 95% confidence interval (CI) = 0.49-0.59];insulin use (OR = 1.63, 95% CI = 1.26-2.11); multi facility for HbA1c testing (OR = 5.51, 95% CI = 4.66-6.51); more than 48 outpatient days per year (OR = 2.13, 95% CI = 1.81-2.51); hospitalizations (OR = 0.66, 95% CI = 0.55-0.79); two or more classes of antidiabetic agents at baseline (OR = 1.32, 95% CI = 1.11-1.56); and dementia at baseline (OR = 0.70, 95% CI = 0.51-0.97) were significantly associated with high-frequency HbA1c testing. No significant association between frequent HbA1c testing and the number of all-cause hospitalizations was found. Conclusions: We revealed a high rate of HbA1c testing among older Japanese patients with type 2 diabetes in ambulatory care and indicated that high-frequency HbA1c testing was more likely to result from the decentralized healthcare system and its structure.

Risk factors for in-hospital mortality in patients with advanced lung cancer with interstitial pneumonia undergoing systemic chemotherapy: A retrospective and observational study using a nationwide administrative database in Japan.

BACKGROUND: The safety profile of systemic chemotherapy for lung cancer patients with interstitial pneumonia (IP) in clinical practice remains unclear. Using Diagnostic Procedure Combination (DPC) data from the Japanese administrative database, we investigated the mortality of hospitalized lung cancer patients with IP as they underwent a course of systemic chemotherapy nationwide. METHODS: The DPC data of patients with stage IIIB or IV lung cancer as defined by the Union for International Cancer Control Tumor-Nodes-Metastases 6th and 7th editions from April 2014 to March 2016 were obtained. Among those patients, only patients with concomitant IP and receiving systemic chemotherapy without radiotherapy were included. RESULTS: Among 1524 included patients, 70 (4.6%) died in the hospital. Multivariate analysis revealed that low activities of daily living (ADL) scores on admission (hazard ratio [HR] 2.26, 95% confidence interval [CI] 1.24-4.12, p = 0.008) and high-dose corticosteroid therapy following chemotherapy (HR 2.62, 95% CI 1.44-4.77, p = 0.002) were strongly associated with in-hospital mortality. It was determined that patients possibly received high-dose corticosteroids for IP exacerbations; these patients had a higher in-hospital mortality rate of 67.7% (21/31 patients) and a significantly shorter median survival time of 55 days (95% CI 31-69 days, p < 0.001) than those who did not receive high-dose corticosteroids. CONCLUSION: Acute exacerbation of IP treated with systemic high-dose corticosteroids is significantly associated with in-hospital mortality, and a low ADL score on admission is a risk factor for in-hospital mortality in lung cancer patients with IP who undergo systemic chemotherapy.

Pre-transplant Rehabilitation to Decrease the Post-transplant Length of Stay for Hematological Malignancy Patients Undergoing Allo-HSCT.

OBJECTIVES: Pre-transplant rehabilitation for hematological malignancy patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) helps improve physical capacity. However, its benefit with respect to post-transplant hospital length of stay (LOS) is unclear. Consequently, the aim of this study was to investigate the effect of pre-transplant rehabilitation on post-transplant LOS for hematological malignancy patients undergoing allo-HSCT. METHODS: Data on patients diagnosed between April 2014 and March 2017 were collected from the Japanese Diagnosis Procedure Combination database. The patients were identified using the ICD-10 codes C81-85, C90-94, C96, and D46. Multilevel linear regression analyses were conducted to identify the effects of pre-transplant rehabilitation on post-transplant LOS (log transformed). RESULTS: In total, 3614 patients were included in the study. Pre-transplant rehabilitation was associated with a significant reduction in post-transplant hospital LOS (ß=-0.134, P<0.001). CONCLUSIONS: Pre-transplant rehabilitation may be an effective strategy for shortening the post-transplant hospital LOS in hematological malignancy patients undergoing allo-HSCT. Consequently, it may be necessary to consider starting rehabilitation before transplantation.

Work functioning impairment in the course of pharmacotherapy treatment for depression.

This study investigated the association between the duration of pharmacotherapy treatment for depression, or discontinuation from treatment, and work functioning impairment. This was a retrospective cohort study examining 30,409 workers. Work functioning impairment was assessed using a questionnaire, and treatment status was assessed using medical claims data. Odds ratios (ORs) of workers with severe work functioning impairment compared with healthy workers (control group) were calculated using logistic regression analysis. Continuous medical treatment was associated with severely impaired work functioning regardless of treatment period [continuous medical treatment; 4 months <: OR = 3.2, 4 months ≥, 10 months <: OR = 2.6, 10 months ≥, 14 months <: OR = 2.3, 14 months ≥, 16 months <: OR = 2.3, which are all statistically significant (p < 0.05)]. Workers who initially received pharmacotherapy treatment but discontinued in < 11 months had a significantly higher OR (treatment discontinuation period; 3 months <: OR = 2.3, 3 months ≥, 8 months <; OR = 2.0, 8 months ≥, 11 months <; OR = 3.0), while those who discontinued at ≥ 11 months did not (OR = 1.4, 95% CI 0.6-3.5). The sensitivity analysis excluding participants with at least one psychiatric comorbidity other than depression did not change the final result. It is important for the occupational health practitioners and attending psychiatrists to follow up in cooperation with each other, paying attention to the decrease in work functioning in addition to the symptoms.

Cardiovascular and cerebrovascular diseases risk associated with the incidence of presenteeism and the costs of presenteeism.

OBJECTIVES: The objective of this study was to estimate a risk of cardiovascular and cerebrovascular diseases for each worker and to determine whether this risk is associated with the incidence and costs of presenteeism, absenteeism, and medical/drug treatments. METHODS: Established risk equations were used to estimate the 10-year probability of developing coronary artery disease and ischemic stroke in male workers aged 40-65 years who were recruited from four pharmaceutical companies in Japan. The incidence of presenteeism was defined as existence of presenteeism for the past a month, and the incidence of absenteeism was defined as existence of sick-leave for the past three months by a self-administered questionnaire. Each cost was calculated based on the human capital method. Data on medical/drug treatments were collected from health insurance claims. RESULTS: The risks were calculated for 6047 workers. Individuals at moderate and high risk of coronary artery disease had a significantly higher rate of presenteeism and absenteeism than workers at low risk. Workers at moderate and high risk of ischemic stroke also had a significantly higher rate of presenteeism and absenteeism than workers at low risk. Mean costs for absenteeism and medical/drug treatments increased with the risk of developing coronary artery disease or ischemic stroke, while costs for presenteeism did not. CONCLUSIONS: To prevent the costs of presenteeism, workers not only at high risk but also at low and moderate risk of developing cardiovascular and cerebrovascular diseases should receive health care services.

Validation of self-reported medication use for hypertension, diabetes, and dyslipidemia among employees of large-sized companies in Japan.

OBJECTIVE: The aim of this study was to evaluate the validity of self-reported medication use for hypertension, diabetes, and dyslipidemia by comparison with health insurance claims among employees of large-sized companies in Japan. METHODS: Participants were 61 676 participants of 13 large-sized companies in Japan. Self-reports on medication use were obtained through web- or paper-based questionnaires conducted at the annual health checkup in fiscal year 2016. Health insurance claims for medication were obtained from corporate health insurance associations from April 1, 2016, to March 31, 2017. Agreement rate, sensitivity, specificity, positive and negative predictive values (PPV and NPV), and kappa statistics of self-reporting were examined for different reference periods (1-, 2-, and 3- months, and 1-year). Subgroup analysis was conducted stratified by sex, age, body mass index, smoking, alcohol drinking, blood pressure, hemoglobin A1c, and low-density lipoprotein cholesterol. RESULTS: Agreement, sensitivity, specificity, PPV, and NPV were 0.98, 0.90, 0.98, 0.87, and 0.99 for hypertension, 0.99, 0.89, 1.00, 0.89, and 1.00 for diabetes, and 0.98, 0.86, 0.99, 0.83, and 0.99 for dyslipidemia, respectively, between self-reports and claims data for 3 months. Kappa statistics were highest with the 3-month reference period of claims data for hypertension, diabetes, and dyslipidemia. No major concordance was observed between the subgroups. CONCLUSION: This validation of self-reported medication use for hypertension, diabetes, and dyslipidemia showed almost perfect reliability among employees of large-sized companies in Japan.

Equality of Treatment for Hip Fracture Irrespective of Regional Differences in Socioeconomic Status: Analysis of Nationwide Hospital Claims Data in Japan.

Despite the wide variety of international evidence on the relationship between the socioeconomic status (SES) and health outcomes, less is known about the association between SES and healthcare provider practices. We assessed whether patients with a closed hip fracture were treated differently by hospital physicians according to the SES of their residential areas in Japan. Hip fracture is a common cause of hospitalization among the elderly, but the relationship between SES and hip fracture treatment remains unknown in Japan. We employed the Diagnosis Procedure Combination (DPC) database from April 2011 to March 2014. SES of the patient's residential area was estimated using Census-derived areal deprivation index (ADI). We performed a cross-sectional study of national claims data and analyzed it using cross-classified multilevel models. We used two outcome measures: (i) whether the patient received an operation or was treated by watchful waiting; and (ii) number of waiting days until operation following admission. We identified 95,011 patients admitted to 1,050 hospitals. Of these, 85,480 patients underwent surgery. Low SES of residential areas was not correlated with the chance of undergoing surgery (P = 0.15) but was weakly correlated with longer waiting days (coefficient, 0.03; 95% confidence interval, -0.01 to 0.06; P = 0.08). The difference of waiting days between maximum (10.4) and minimum ADI (-4.0) was marginal (0.39 days). The results indicate the SES of patient's residential area does not affect the decision of surgical treatment for hip fracture and has ignorable impact on waiting days from hospital admission to surgery.

Total Health-Related Costs Due to Absenteeism, Presenteeism, and Medical and Pharmaceutical Expenses in Japanese Employers.

OBJECTIVE: This study aimed to examine a detailed breakdown of costs (absenteeism, presenteeism, and medical/pharmaceutical expenses), of the employees in four pharmaceutical companies in Japan. METHODS: This is a cross-sectional study. Absenteeism and presenteeism were measured by a self-administered questionnaire for workers, and their costs were estimated using the human capital approach. Presenteeism was evaluated by the degree affected quality and quantity of work. Medical and pharmaceutical expenses were obtained by insurance claims. RESULTS: The monetary value due to absenteeism was $520 per person per year (11%), that of presenteeism was $3055 (64%), and medical/pharmaceutical expenses were $1165 (25%). Two of the highest total cost burdens from chronic illness were related to mental (behavioral) health conditions and musculoskeletal disorders. CONCLUSION: A total cost approach can help employers set priorities for occupational health, safety, and population health management initiatives.

The Current Status of Microvascular Decompression for the Treatment of Trigeminal Neuralgia in Japan: An Analysis of 1619 Patients Using the Japanese Diagnosis Procedure Combination Database.

Microvascular decompression (MVD) is a widely used, safe, and effective treatment for trigeminal neuralgia (TGN). However, the extent of application of this therapeutic method and its outcomes in Japan are currently unclear. To address these questions, the authors analyzed the use of MVD for the treatment of TGN during the 33-month period from July 2010 to March 2013, using data contained in the Diagnosis Procedure Combination database. The analysis revealed that MVD was used for the treatment of TGN in 1619 cases (608 men, 1011 women), with approximately 1.66 times more women treated than men. MVD for TGN was most frequently performed in individuals 60 to 79 years of age; of particular note was the remarkable increase in the number of women in this particular category. The overall number of procedures performed per 100,000 population/year in Japan was 0.46. The number of procedures was larger in prefectures with higher populations, with a tendency toward a higher number of MVD procedures performed in the area designated West than in the East. Discharge outcomes indicated that cure and improvement were achieved in 97.6% of cases, with a mortality rate of 0.2%, and no differences in discharge outcomes between men and women. The mean length of hospital stay in patients undergoing MVD for TGN was 14.8 days. This analysis revealed discernable trends in the use of MVD for the treatment of TGN in Japan.

The Current Status of Microvascular Decompression for the Treatment of Hemifacial Spasm in Japan: An Analysis of 2907 Patients Using the Japanese Diagnosis Procedure Combination Database.

Microvascular decompression (MVD) is widely used as a safe and effective treatment for hemifacial spasm (HFS). However, the extent of application of this therapeutic method and its outcomes in Japan are currently unclear. To address these questions, we analyzed the utilization of MVD for the treatment of HFS during the 33- month period from July 2010 to March 2013. We conducted an analysis on data contained in the Diagnosis Procedure Combination database in Japan. This analysis showed that MVD was used for the treatment of HFS in 2907 cases (men, 916; women, 1991) with 2.2 times more women treated than men. MVD for HFS was most frequently performed in women aged 50 to 69 years; however, most men were aged between 40 and 59 years at the time of the procedure. The numbers of procedures performed per 100,000 population/year were 0.83 overall in Japan, with the numbers larger in prefectures with larger populations. Regarding discharge outcomes, the mortality rate was 0.1%. The mean length of hospital stay in patients undergoing MVD for HFS was 14.7 days. This analysis provides preliminary information regarding the trends in the performance of MVD for the treatment of HFS in Japan. Further studies on other registries that contain data obtained by standardized assessment methods and that include long-term outcomes and postoperative complications are required.

Time Trend of Outcomes for Severe Acute Pancreatitis After Publication of Japanese Guidelines Based on a National Administrative Database.

OBJECTIVES: This study aimed to investigate the recent time trend of outcomes for severe acute pancreatitis after publication of Japanese guidelines based on a national administrative database. METHODS: A total of 10,400 patients with severe acute pancreatitis were referred to 1021 hospitals between 2010 and 2012 in Japan. We collected patients' data from the administrative database to compare in-hospital mortality (within 28 days and overall), length of stay (LOS), and medical costs during hospitalization. The study periods were categorized into 3 groups according to fiscal year: 2010 (n = 2698), 2011 (n = 3842), and 2012 (n = 3860). RESULTS: In-hospital mortality within 28 days and overall in-hospital mortality were significantly decreased according to fiscal year (6.3% [2010] vs 5.7% [2011] vs 4.5% [2012], P = 0.005; 7.6% vs 7.1% vs 5.6%, P = 0.002, respectively). However, mean LOS and medical costs were not different between fiscal years (27.0 vs 27.1 vs 26.9 days, P = 0.218; 13,998.0 vs 14,156.4 vs 14,319.2 USD, P = 0.232, respectively). CONCLUSIONS: This study shows that mortality of severe acute pancreatitis was reduced according to the time course, whereas LOS or medical costs were stable after publication of the Japanese guidelines.

Influence of comorbidity on outcomes of older patients with acute pancreatitis based on a national administrative database.

BACKGROUND: Little information is available on the influence of comorbidities on outcomes of older patients with acute pancreatitis. This study aimed to investigate the influence of comorbidities on outcomes of older patients with acute pancreatitis using data from a national Japanese administrative database. METHODS: A total of 14 322 older patients (≥70 years) with acute pancreatitis were referred to 1090 hospitals between 2010 and 2012 in Japan. We collected patients' data from the administrative database to compare the in-hospital mortality and length of stay of older patients with acute pancreatitis. The patients were categorized into four groups according to comorbidity level using the Charlson Comorbidity Index (CCI): none (CCI score=0; n=6890); mild (1; n=3874); moderate (2; n=2192) and severe (≥3; n=1366). RESULTS: Multiple logistic and linear regression analyses revealed that severe comorbidity was significantly associated with higher in-hospital mortality and longer length of stay [odds ratio (OR)=2.26; 95% confidence interval (CI): 1.75-2.92, P<0.001 and coefficient 4.37 days; 95% CI: 2.89-5.85, P<0.001, respectively]. In addition, cardiovascular and renal diseases were the most significant comorbidities affecting outcomes of the older patients. ORs of cardiovascular and renal diseases for mortality were 1.44 (95% CI: 1.13-1.85, P=0.003) and 2.69 (95% CI: 1.88-3.85, P<0.001), respectively, and coefficients for length of stay were 3.01 days (95% CI: 1.34-4.67, P<0.001) and 3.72 days (95% CI: 1.01-6.42, P=0.007), respectively. CONCLUSION: This study demonstrated that comorbidities significantly influenced outcomes of older patients with acute pancreatitis and cardiovascular and renal comorbidities were significant factors affecting outcomes.

Effects of proton pump inhibitor on outcomes of patients with severe acute pancreatitis based on a national administrative database.

OBJECTIVE: This study aimed to investigate whether proton pump inhibitors (PPIs) affect the outcomes of patients with severe acute pancreatitis based on a national administrative database. METHODS: A total of 10,400 patients with severe acute pancreatitis were referred to 1021 hospitals between 2010 and 2012 in Japan. Patients were divided into two groups: patients who used PPIs (n = 3879) and those without PPIs (n = 6521). We collected patients' data from the administrative database to compare in-hospital mortality within 7, 14, and 28 days, and overall in-hospital mortality between groups, using propensity score analysis to adjust for treatment selection bias. RESULTS: Multiple logistic regression showed that use of PPIs did not affect in-hospital mortality within 7 and 14 days. The odds ratio (OR) for mortality within 7 days was 1.14 (95% confidence interval [CI]: 0.91-1.42, p = 0.236) while that within 14 days was 1.10 (95% CI: 0.89-1.35, p = 0.349). No significant association was observed for in-hospital mortality within 28 days and overall in-hospital mortality (OR for within 28 days: 1.12, 95% CI: 0.92-1.37, p = 0.224; OR for overall in-hospital mortality: 1.42, 95% CI: 0.97-1.87, p = 0.065). CONCLUSIONS: This study shows that use of PPIs does not affect clinical outcomes of patients with severe acute pancreatitis. Prospective or randomized studies are needed to confirm the efficacy of PPIs on outcomes of patients with severe acute pancreatitis in the future.

Effect of dementia on outcomes of elderly patients with hemorrhagic peptic ulcer disease based on a national administrative database.

BACKGROUND: Little information is available on the effect of dementia on outcomes of elderly patients with hemorrhagic peptic ulcer disease at the population level. AIMS: This study aimed to investigate the effect of dementia on outcomes of elderly patients with hemorrhagic peptic ulcer based on a national administrative database. METHODS: A total of 14,569 elderly patients (≥80 years) who were treated by endoscopic hemostasis for hemorrhagic peptic ulcer were referred to 1073 hospitals between 2010 and 2012 in Japan. We collected patients' data from the administrative database to compare clinical and medical economic outcomes of elderly patients with hemorrhagic peptic ulcers. Patients were divided into two groups according to the presence of dementia: patients with dementia (n = 695) and those without dementia (n = 13,874). RESULTS: There were no significant differences in in-hospital mortality within 30 days and overall mortality between the groups (odds ratio; OR 1.00, 95 % confidence interval; CI 0.68-1.46, p = 0.986 and OR 1.02, 95 % CI 0.74-1.41, p = 0.877). However, the length of stay (LOS) and medical costs during hospitalization were significantly higher in patients with dementia compared with those without dementia. The unstandardized coefficient for LOS was 3.12 days (95 % CI 1.58-4.67 days, p < 0.001), whereas that for medical costs was 1171.7 US dollars (95 % CI 533.8-1809.5 US dollars, p < 0.001). CONCLUSIONS: Length of stay and medical costs during hospitalization are significantly increased in elderly patients with dementia undergoing endoscopic hemostasis for hemorrhagic peptic ulcer disease.

Effect of hospital volume on outcomes of laparoscopic appendectomy for acute appendicitis: an observational study.

BACKGROUND: This study investigated the effect of hospital volume on outcomes of laparoscopic appendectomy for acute appendicitis. METHODS: In total, 30,525 patients who underwent laparoscopic appendectomy for acute appendicitis were referred to 825 hospitals in Japan from 2010 to 2012. We compared appendectomy-related complications, length of stay (LOS), and medical costs in relation to hospital volume. For this study period, hospitals were categorized as low-volume hospitals (LVHs, <50 cases), medium-volume hospitals (MVHs, 50-100 cases), or high-volume hospitals (HVHs, >100 cases). RESULTS: Significant differences in appendectomy-related complications were observed among the LVHs, MVHs, and HVHs (6.9, 7.2, and 6.0 %, respectively; p = 0.001). Multiple logistic regression revealed that HVHs were associated with a lower relative risk of appendectomy-related complications than were LVHs and MVHs (odds ratio [OR], 0.84; 95 % confidence interval [CI], 0.74-0.95; p = 0.006). Multiple linear regression showed that HVHs were associated with shorter LOS and lower medical costs than were LVHs and MVHs. The unstandardized coefficient for LOS was -0.92 days (95 % CI, -1.07 to -0.78; p < 0.001), whereas that for medical costs was - $167.4 (95 % CI, -256.2 to -78.6; p < 0.001). CONCLUSIONS: Hospital volume was significantly associated with laparoscopic appendectomy outcomes.

Mycoplasma removal from cell culture using antimicrobial photodynamic therapy.

OBJECTIVE: The objective of this research was to determine the effectiveness of antimicrobial photodynamic therapy (aPDT) in the removal of mycoplasmas from contaminated cells. BACKGROUND DATA: Mycoplasmas often contaminate cell cultures. The cell-contaminating mycoplasmas are removed by antibiotics, but the use of antibiotics usually induces antibiotic-resistant bacteria. aPDT is expected to be a possible alternative to antibiotic treatments for suppressing infections. MATERIALS AND METHODS: Mycoplasma salivarium (Ms)-infected human embryonic kidney (HEK) 293 cells were irradiated using a red light-emitting diode (LED) in the presence of methylene blue (MB) as a photosensitizer. The Ms viable count was determined using culture on agar plates or using a mycoplasma detection kit. RESULTS: aPDT performed using red LED irradiation was effective in decreasing live Ms in the presence of MB without damaging the HEK293 cells. aPDT removed live Ms from the infected cells after washing the cells with sterilized phosphate-buffered saline (PBS) to decrease the initial number of live Ms before aPDT. CONCLUSIONS: This study suggests that aPDT could remove mycoplasmas from contaminated cells.

Involvement of suppressor of cytokine signalling-1-mediated degradation of MyD88-adaptor-like protein in the suppression of Toll-like receptor 2-mediated signalling by the murine C-type lectin SIGNR1-mediated signalling.

Dendritic cells recognize pathogens through pattern recognition receptors such as Toll-like receptors and phagocytose and digest them by phagocytic receptors for antigen presentation. This study was designed to clarify the cross-talk between recognition and phagocytosis of microbes in dendritic cells. The murine dendritic cell line XS106 cells were stimulated with the murine C-type lectin SIGNR1 ligand lipoarabinomannan and the Toll-like receptor 2 ligand FSL-1. The co-stimulation significantly suppressed FSL-1-mediated activation of NF-κB as well as production of TNF-α, IL-6 and IL-12p40 in a dose-dependent manner. The suppression was significantly but not completely recovered by knock-down of SIGNR1. SIGNR1 was associated with Toll-like receptor 2 in XS106 cells. The co-stimulation upregulated the expression of suppressor of cytokine signalling-1 in XS106 cells, the knock-down of which almost completely recovered the suppression of the FSL-1-mediated cytokine production by lipoarabinomannan. In addition, it was found that the MyD88-adaptor-like protein in XS106 cells was degraded by co-stimulation with FSL-1 and lipoarabinomannan in the absence, but not the presence, of the proteasome inhibitor MG132 and the degradation was inhibited by knock-down of suppressor of cytokine signalling-1. This study suggests that Toll-like receptor 2-mediated signalling is negatively regulated by SIGNR1-mediated signalling in dendritic cells, possibly through suppressor of cytokine signalling-1-mediated degradation of the MyD88-adaptor-like protein.

In vivo anti- and pro-tumour activities of the TLR2 ligand FSL-1.

TLR ligands as Th1 inducers have been investigated as potential anti-tumour agents. However, few attempts have been made to investigate the anti-tumour activity of TLR ligands as Th2 inducers. This study, therefore, was carried out to determine whether the TLR2 ligand FSL-1 as a Th2 inducers affects the growth of a QRsP tumour, a fibrosarcoma derived from the C57BL/6 (TLR2(+/+)) mouse in vivo. Tumour volumes in TLR2(+/+) mice immunized with both FSL-1 and tumour-associated antigens were significantly smaller than those in control mice. Immunization with both FSL-1 and tumour-associated antigens increased the survival rate of TLR2(+/+) mice. However, surprisingly, immunization with FSL-1 alone significantly enhanced the growth of tumour. Both anti- and pro-tumour activities of FSL-1 were not observed in TLR2(-/-) mice. Immunization of both FSL-1 and tumour-associated antigens induced tumour-associated antigen-specific cytolytic T cells, antibody-dependent cell-mediated cytotoxicity of natural killer cells by production of the tumour-specific antibodies, tumour lysis by complement activation and reduction of the number of regulatory T cells in the draining lymph node. Immunization with FSL-1 alone increased the number of regulatory T cells in the draining lymph node, and in vivo administration of anti-CD25 antibody into mice abrogated the pro-tumour activity of FSL-1, suggesting that regulatory T cells are involved in the pro-tumour activity. This study demonstrated that FSL-1 exhibited TLR2-mediated anti- and pro-tumour activities when immunized with and without tumour-associated antigens, respectively.

The Toll-like receptor 2 (TLR2) ligand FSL-1 is internalized via the clathrin-dependent endocytic pathway triggered by CD14 and CD36 but not by TLR2.

Little is known of how Toll-like receptor (TLR) ligands are processed after recognition by TLRs. This study was therefore designed to investigate how the TLR2 ligand FSL-1 is processed in macrophages after recognition by TLR2. FSL-1 was internalized into the murine macrophage cell line, RAW264.7. Both chlorpromazine and methyl-beta-cyclodextrin, which inhibit clathrin-dependent endocytosis, reduced FSL-1 uptake by RAW264.7 cells in a dose-dependent manner but nystatin, which inhibits caveolae- and lipid raft-dependent endocytosis, did not. FSL-1 was co-localized with clathrin but not with TLR2 in the cytosol of RAW264.7 cells. These results suggest that internalization of FSL-1 is clathrin dependent. In addition, FSL-1 was internalized by peritoneal macrophages from TLR2-deficient mice. FSL-1 was internalized by human embryonic kidney 293 cells transfected with CD14 or CD36 but not by the non-transfected cells. Also, knockdown of CD14 or CD36 in the transfectants reduced FSL-1 uptake. In this study, we suggest that (i) FSL-1 is internalized into macrophages via a clathrin-dependent endocytic pathway, (ii) the FSL-1 uptake by macrophages occurs irrespective of the presence of TLR2, and (iii) CD14 and CD36 are responsible for the internalization of FSL-1.