Inhibitory Effects of Polymyxin B and Human LL-37 on the Flagellin Expression in Vibrio vulnificus.

Vibrio vulnificus, an opportunistic human pathogen responsible for primary septicemia, initiates pathogenesis by attachment to the intestinal epithelial cells for which the motility by the polar flagellum plays an essential role. The proteomic analysis of outer membrane proteins showed that the treatment with the 1/2 minimum inhibitory concentration (MIC) of polymyxin B (a bacterial antimicrobial peptide) led to the reduced production of flagellin (a major component of the polar flagellum). Furthermore, the bacterial motility was inhibited in the presence of 1/2 MIC of polymyxin B. V. vulnificus has six flagellin genes organized into the flaFBA and flaCDE loci. The flaA was found to be expressed higher than flaC, and its expression was significantly decreased by polymyxin B. As well as polymyxin B, the 1/2 MIC of LL-37 (a human intestinal antimicrobial peptide) reduced the expression of flaA. In addition, among four fragments of LL-37, KI-18 and FK-13 containing F17KRIVQRIKDELR29 could lead to the decreased expression of flaA. Because the motility closely relates to virulence of V. vulnificus, the findings obtained herein indicate that LL-37 may reduce the bacterial virulence through inhibition of the motility via the polar flagellum.

Two Blautia Species Associated with Visceral Fat Accumulation: A One-Year Longitudinal Study.

Intestinal microflora has been associated with obesity. While visceral fat is more strongly associated with cardiovascular disorder, a complication linked to obesity, than the body mass index (BMI), the association between intestinal microflora and obesity (as defined in terms of BMI) has been studied widely. However, the link between visceral fat area (VFA) and intestinal microflora has been little studied. In this study, we investigate the association between intestinal microflora and VFA and BMI using a longitudinal study on Japanese subjects with different VFA statuses (N = 767). Principal component analysis of the changes in intestinal microflora composition over the one-year study period revealed the different associations between intestinal microflora and VFA and BMI. As determined by 16S rRNA amplicon sequencing, changes in the abundance ratio of two microbial genera-Blautia and Flavonifractor-were significantly associated with VFA changes and changes in the abundance ratio of four different microbial genera were significantly associated with BMI changes, suggesting that the associated intestinal microbes are different. Furthermore, as determined by metagenomic shotgun sequences, changes in the abundance ratios of two Blautia species-Blautia hansenii and Blautia producta-were significantly and negatively associated with VFA changes. Our findings might be used to develop a new treatment for visceral fat.

The effect of age on the association between daily gait speed and abdominal obesity in Japanese adults.

The aim of this work was to investigate the effect of age on the association between daily gait speed (DGS) and abdominal obesity defined by visceral fat area (VFA). A cross-sectional study was performed using data from an annual community-based health check-up. A total of 699 participants aged 20-88 years were enrolled in this analysis. DGS was assessed using tri-axial accelerometers worn for ≥ 7 days with at least 10 measuring hours each day. VFA was measured using a visceral fat meter. Since DGS differed significantly with age, the participants were divided into two groups: younger adults (YA), aged 20-49 years, and older adults (OA), aged 50-88 years. The association between DGS and VFA differed significantly with age (r = 0.099 for YA and r = - 0.080 for OA; test for difference between correlation coefficients, P = 0.023). In OA, the adjusted odds ratio of abdominal obesity (VFA ≥ 100 cm2) was 0.40 (95% confidence interval 0.18, 0.88, P = 0.022) for the highest DGS quartile (DGS ≥ 1.37 m/s) compared to that for the lowest quartile (DGS < 1.11 m/s), whereas no significant association was found in YA. These data could aid in raising awareness of the self-management of obesity via DGS monitoring, especially in OA.

Relationship between abnormalities detected by magnetic resonance imaging and knee symptoms in early knee osteoarthritis.

We investigated the prevalence of magnetic resonance imaging (MRI) findings and their relationship with knee symptoms in women without radiographic evidence of knee osteoarthritis (KOA). This cross-sectional cohort study included 359 Japanese women without radiographic evidence of KOA (Kellgren‒Lawrence grade < 2). All participants underwent T2-weighted fat-suppressed MRI of their knees. Structural abnormalities (cartilage damage, bone marrow lesions [BMLs], subchondral cysts, bone attrition, osteophytes, meniscal lesions, and synovitis) were scored according to the whole-organ MRI score method. Knee symptoms were evaluated using the Knee Injury and Osteoarthritis Outcome Score. Participants were divided into early and non-KOA groups based on early KOA classification criteria. Logistic regression analysis was performed to evaluate the relationship between MRI abnormalities and knee symptoms. Cartilage damage was the most common abnormality (43.5%). The prevalences of cartilage damage, BMLs, subchondral cysts, bone attrition, meniscal lesions, and synovitis were higher in patients with early KOA than in those without. Synovitis (odds ratio [OR] 2.254, P = 0.002) and meniscal lesions (OR 1.479, P = 0.031) were positively associated with the presence of early KOA. Synovitis was most strongly associated with knee pain and might be a therapeutic target in patients with early KOA.

Overactive bladder and sleep disturbance have a significant effect on indoor falls: Results from the community health survey in Japan.

OBJECTIVES: To evaluate the effect of overactive bladder (OAB) and frailty on indoor fall events in community-dwelling adults aged 50 or older. METHODS: We conducted a cross-sectional study involving 723 adults between 2016 and 2017 in Hirosaki, Japan. OAB symptoms and sleep disturbance were assessed using the Overactive Bladder Symptom Score (OABSS) and the Pittsburgh Sleep Quality Index (PSQI). Indoor fall events (falls or near-falls) within 1 year were evaluated. Frailty was evaluated by the frailty discriminant score. We investigated the association of OAB symptoms with sleep disturbance, frailty, and indoor fall events. Multivariate logistic regression analysis was performed to investigate the effect of OAB symptoms on fall events controlling for confounding factors such as age, gender, comorbidity, frailty, and sleep disturbance. RESULTS: The median age was 64. We observed OABSS ≥6 in 98 participants (14%), nocturia ≥2 in 445 (62%), urgency score ≥3 in 80 (11%), urge incontinence score ≥3 in 36 (5.0%), PSQI ≥6 in 153 (21%), frailty in 169 (23%), and indoor fall events in 251 (35%). Older age, diabetes, OABSS, nocturia, urgency, urge incontinence, and the PSQI were significantly associated with indoor fall events. Multivariate logistic regression analyses showed that OAB symptoms and sleep disturbance were significantly associated with fall events. CONCLUSIONS: The effect of OAB symptoms and sleep disturbance on indoor fall events was significant. The causal relationship between OAB and falls needs further study.

A Longitudinal Study of Bidirectional Relationships between Sleep Disorder and Frequency of Nocturia: Results from the Iwaki Health Promotion Project.

INTRODUCTION: The causal relationship between sleep disorder and frequency of nocturia remains unclear. METHODS: We longitudinally evaluated sleep disorder and frequency of nocturia in 547 community-dwelling adults between baseline and 5-year follow-up. We included participants ≥50 years old who have no sleep disorder (the Pittsburgh Sleep Quality Index [PSQI] ≥ 5) nor nocturia (≥1). For 5 years, we evaluated the temporal changes in sleep disorder and nocturia and the bidirectional relationships between sleep disorder and nocturia. RESULTS: Of the 547 participants, we included 268 adults with a median age of 61 years in this study. Median PSQI and nocturia were significantly increased for 5 years from 2 to 3 and from 1 to 2, respectively. New onset of sleep disorder (PSQI > 5) and nocturia >1 was observed in 42 (16%) and 137 (51%) participants, respectively. The cross-lagged panel analysis showed that the path coefficient from PSQI to nocturia (ß = 0.22, p = 0.031) was significantly higher than that from nocturia to PSQI (ß = 0.02, p = 0.941). CONCLUSIONS: Our longitudinal study showed the effect of sleep disorder on nocturia was significant, although nocturia may not significantly worsen sleep disorder in community-dwelling adults.

Relationship between Selected Trace Elements and Hematological Parameters among Japanese Community Dwellers.

This study aimed (1) to assess serum trace elements concentrations and hematological parameters, (2) to evaluate the sex differences in the associations between serum trace elements levels and hematological parameters, and (3) to identify the associations between serum trace elements concentrations and risk of anemia among Japanese community dwellers. This is a community-based cross-sectional study that utilized the data of the 2014 Iwaki Health Promotion Project. Participants were 1176 community dwellers (>18 years) residing in the Iwaki District, Aomori Prefecture, Japan. We assessed the data of serum trace elements concentrations of cadmium (Cd), cobalt (Co), copper (Cu), selenium (Se), zinc (Zn), and iron (Fe) as well as the hematological parameters of red blood cells (RBC) counts, hemoglobin, packed cells volume (PCV), mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH). Serum concentrations of Zn (871.5 µg/L vs. 900.1 µg/L) and Fe (946.8 µg/L vs. 1096.1 µg/L) were significantly lower in females than in males, while serum concentrations of Co (0.4 µg/L vs. 0.3 µg/L) and Cu (1062.4 µg/L vs. 965.3 µg/L) were significantly higher in females. By multivariate linear regression, serum Se concentration was significantly, positively associated with PCV (ß = 1.04; 95% confidence interval (CI): 0.17, 1.92; p = 0.016) among the study participants. Serum Zn also had positive associations with hemoglobin (ß = 0.42; 95% CI: 0.07, 0.77; p = 0.020), PCV (ß = 1.79; 95% CI: 0.78, 2.81; p < 0.001), and RBCs count (ß = 15.56; 95% CI: 7.31, 31.69; p = 0.002). On the other hand, serum Co concentration was negatively associated with the hematological parameters, particularly in females. Moreover, serum Zn concentration had a decreased risk of anemia (lowest vs. highest quartiles: odds ratio (OR) = 0.42; 95% CI: 0.23, 0.76; p = 0.005) while higher Co concentrations had an increased risk of anemia (lowest vs. highest quartiles: OR = 1.95; 95% CI: 1.04, 3.67; p = 0.037). However, no significant association was found between serum Cu level and hematological parameters. There were substantial sex differences in serum trace elements, implying that trace elements metabolism differed between males and females. Zn can play a protective role in the development of anemia. Surprisingly, increased Co concentration increased the risk of anemia among our study population, which called for further studies to confirm and to consider for speciation analysis.

[Factors related to frequent emergency hospital refusal of ambulance transport calls].

Purpose　Among the factors that adversely affect the time needed for ambulance transport, one factor for which intervention is possible is the time it takes to choose a medical receiving facility. This research clarified the characteristics of the time, location, and severity of medical emergencies in which the choice of hospital was difficult.Methods　The research covered a 1-year period from January 1 through December 31, 2014, investigating all incidents of ambulance transport for patients in Wakayama Prefecture, except for those involving pediatric patients, amounting to a total of 41,574 incidents. Of those, the number of referrals was missing in 129 cases and the remaining 41,445 incidents were analyzed. Cases with 4 or more referrals were adopted as an indicator of difficulty in choosing a hospital. Using binary logistic regression analysis, odds ratios (ORs) with 95% confidence intervals (CIs) were computed for the times and locations of emergency calls, and the degree of injury or illness. A comprehensive analysis was performed, and stratified analysis by Major Diagnostic Category (MDC) was performed, examining external injuries, burns, and poisoning; nervous system disorders; digestive system, liver, biliary tract, and pancreatic disorders; respiratory disorders; and circulatory system disorders.Results　The distribution of numbers of referrals ranged from 1 to 12, and 79.6% of cases involved 1 referral, while cases with 4 or more referrals made up 3.5% of the total. In the overall analysis, for cases with 4 or more referrals, call times were examined using weekday working hours as a reference; all other times had high ORs (at 95%CI). The highest OR (95%CI) of 4.0 (3.2-5.0) was for late nights during weekends and holidays. Regarding the degree of injury or illness, using moderate and mild injuries as a reference, the number of referrals (3 times or fewer) was significantly lower for severe injuries and incidents of death (0.8;0.7-0.9). However, in the results of the stratified analysis by MDC, external injuries, burns, and poisoning; severe injury; and death each had an OR (95%CI) of 1.4 (1.0-1.8).Conclusion　The relationship between the time, location, and severity of medical emergencies was examined using the number of referrals as an indicator of difficulty with hospital choice in ambulance transport. This research clarified that cases late at night during weekends and holidays, and moderate and mild injuries caused the most difficulty, and that the problems depended on the secondary medical district.

A single-arm phase II study of nab-paclitaxel for patients with chemorefractory non-small cell lung cancer.

BACKGROUND: We aimed to evaluate the efficacy and safety of nab-paclitaxel in patients with refractory advanced non-small cell lung cancer who failed previous chemotherapy. METHODS: Patients were required to have an Eastern Cooperative Oncology Group performance status of 0-2 and adequate organ function. Patients received nab-paclitaxel, 100 mg/m2 i.v. on days 1, 8, and 15 every 4 weeks. The primary endpoint was the overall response rate. Secondary endpoints were the progression-free survival time, overall survival, and the toxicity profile. RESULTS: From July 2013 to July 2015, a total of 31 patients were enrolled. Fourteen patients received nab-paclitaxel as a second-line and 17 received it as an over third-line therapy. Each patient received a median of 5 treatment cycles (range, 1-11). The overall response rate was 19.3% (95% confidence interval, 9.1-36.2%) (complete response (n = 0), partial response (n = 6), stable disease (n = 17), and progressive disease (n = 8)). The median progression-free survival time was 4.5 months (95% confidence interval 3.5-6.3 months), median overall survival time was 15.7 months, and 1-year survival rate was 54.8%. Most common grade 3 or 4 non-hematological toxicities were elevated aspartate transaminase level (3.2%) and sensory neuropathy (9.6%). Neutropenia was the most common grade 3 or 4 adverse events (38.6%), and febrile neutropenia developed in 12.9% patients. No treatment-related deaths were observed in this study. CONCLUSION: Primary endpoint was met. Single agent nab-paclitaxel showed significant clinical efficacy and manageable toxicities for patients with chemorefractory advanced non-small cell lung cancer even if late line setting. TRIAL REGISTRATION: UMIN000011696 . The date of registration was July 11th, 2013.

Defensive effects of human intestinal antimicrobial peptides against infectious diseases caused by Vibrio mimicus and V. vulnificus.

Of human pathogenic Vibrio species, V. mimicus causes gastroenteritis whereas V. vulnificus causes fatal septicemia after consumption of contaminated seafood. These two pathogens produce hemolytic toxins termed V. mimicus hemolysin (VMH) and V. vulnificus hemolysin (VVH), respectively. These toxins elicit the cytolysis of various eukaryotic cells, as well as erythrocytes. The human intestine secretes cationic antimicrobial peptides (AMPs) to prevent infectious diseases. Paneth cells in the small intestine secrete α-defensin 5 (HD-5) and epithelial cells in the large intestine produce LL-37. In the present study, we examined the bactericidal activities of AMPs against V. mimicus and V. vulnificus. Although HD-5 showed no bactericidal activity, LL-37 revealed significant activity against both Vibrio species, suggesting that neither V. mimicus nor V. vulnificus can multiply in the large intestine. We also tested whether AMPs had the ability to inactivate the hemolytic toxins. Only HD-5 was found to inactivate VMH, but not VVH, in a dose-dependent manner through the direct binding to VMH. Therefore, it is considered that V. mimicus cannot penetrate the small intestinal epithelium because the cytolytic action of VMH is inactivated by HD-5.

Double-stranded RNA stimulates the expression of monocyte chemoattractant protein-1 in BEAS-2B bronchial epithelial cells.

BEAS-2B bronchial epithelial cells were treated with polyinosinic-polycytidylic acid (poly IC), a synthetic double-stranded RNA (dsRNA) analog, and the expressions of monocyte chemoattractant protein-1 (MCP-1) mRNA and protein were analyzed by reverse transcriptase-polymerase chain reaction and enzyme-linked immunosorbent assay. Poly IC enhanced the expression of MCP-1 and release of mononuclear cell chemotactic activity, which were inhibited by dexamethasone pre-treatment. The poly IC-induced up-regulation of MCP-1 was blocked by 2-aminopurine, a specific inhibitor of dsRNA-dependent protein kinase, but not by nuclear factor (NF)-kappaB inhibitor SN50.

Vascular endothelial growth factor level as a prognostic determinant of small cell lung cancer in Japanese patients.

OBJECTIVE: To clarify the clinical significance of vascular endothelial growth factor (VEGF) in Japanese patients with small cell lung cancer (SCLC). MATERIALS AND METHODS: We measured serum VEGF levels using an enzyme-linked immunosorbent assay in 45 patients with SCLC before treatment and in 38 patients with benign pulmonary disease and in 32 healthy subjects (71 non-malignant subjects). VEGF immunostaining was performed in tissue biopsies obtained from 23 SCLC patients during bronchoscopic examination. RESULTS: Median serum VEGF level was 332 pg/ml in patients with SCLC and 160 pg/ml in non-malignant subjects, respectively. The 95% cut-off level to exclude non-malignant subjects was 500 pg/ml. An elevated VEGF level (>500 pg/ml) was found more frequently in patients with extensive disease of SCLC than in those with the limited disease (p<0.01). A significant positive correlation was found between the serum VEGF level and platelet count in SCLC patients (r=0.389; p=0.0083). Serum VEGF level also correlated with serum lactate dehydrogenase in SCLC patients (r=0.381; p=0.0098). However, it did not correlate with serum neuron-specific enolase and pro-gastrin-releasing peptide level. Patients with the elevated VEGF levels had significantly shorter progression-free time than those with the normal VEGF levels (p<0.05). Patients with the elevated VEGF levels had a significantly shorter overall survival time than those with the normal VEGF levels in univariate survival analysis (p<0.05). Further, the elevated VEGF level remained as a significant determinant of poor survival in multivariate analysis (p<0.01). Serum VEGF level was significantly higher in patients with positive VEGF protein immunoreactivity in tumor tissue in SCLC. CONCLUSION: Elevated serum VEGF levels were associated with poor outcome in SCLC.

15-Deoxy-delta(12,14)-prostaglandin J2 inhibits the IL-1beta-induced expression of granulocyte-macrophage colony-stimulating factor in BEAS-2B bronchial epithelial cells.

15-Deoxy-delta(12,14)-prostaglandin J2 (15d-PGJ2) is an agonist for peroxisome proliferator-activated receptor-gamma (PPAR-gamma), which plays an important role in various biological processes including inflammatory responses. We have addressed the effect of 15d-PGJ2 on the expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) in a cell line derived from human bronchial epithelial cells (BEAS-2B). Besides being a hematopoietic growth factor, GM-CSF activates mature leukocytes and is involved in regulation of inflammatory responses. Cultures of BEAS-2B were stimulated with interleukin-1beta (IL-1beta), and the expressions of GM-CSF mRNA and protein were analyzed by reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. IL-1beta stimulated the expression of GM-CSF in BEAS-2B cells in concentration- and time-dependent manners. When the cells were pretreated with 15d-PGJ2 for 1 hour, the IL-1beta-induced GM-CSF expression was inhibited in a concentration-dependent manner (2-50 microM). Ciglitazone, another agonist of PPAR-gamma, did not affect the IL-1beta-induced GM-CSF expression in BEAS-2B cells. A PPAR-gamma antagonist, bisphenol A diglycide ether (BADGE), did not reverse the inhibitory effects of 15d-PGJ2 on GM-CSF expression. 15d-PGJ2 regulates GM-CSF expression in the bronchial epithelium, which may be mediated through a mechanism unrelated to PPAR-gamma.

Effect of 15-deoxy-delta12,14-prostaglandin J2 on IL-1beta-induced expression of epithelial neutrophil-activating protein-78 in human endothelial cells.

Epithelial neutrophil-activating peptide-78 (ENA-78) is a member of CXC chemokines. It is produced by endothelial cells stimulated with interleukin-1 (IL-1), along with other CXC chemokines such as IL-8 and growth-related oncogene protein-alpha (GRO-alpha). IL-1-induced ENA-78 production by endothelial cells may be important for the regulation of neutrophil activation. 15-Deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)) is a natural ligand for peroxisome proliferator-activated receptor-gamma (PPAR-gamma) and affects the expression of various genes. We examined the effect of 15d-PGJ(2) on the expression of ENA-78 in cultured endothelial cells stimulated with IL-1beta. 15d-PGJ(2) inhibited the IL-1beta-induced expression of ENA-78, but not the expression of IL-8 or GRO-alpha in response to IL-1. Ciglitazone, another agonist for PPAR-gamma, had no effect on the expression of ENA-78, suggesting that 15d-PGJ(2) may inhibit the expression of ENA-78 in a PPAR-gamma-independent manner. 15d-PGJ(2) may modulate inflammatory reactions by regulating the balance of CXC chemokines in endothelial cells.

Effect of hypoxia on the expression of fractalkine in human endothelial cells.

CX3CL1/fractalkine is a chemokine with a unique CX3C motif. Hypoxia mediates the expression of various genes, such as vascular endothelial growth factor (VEGF), cyclooxygenase-2, and plasminogen-activator inhibitor-1, in vascular endothelial cells. We studied the effect of hypoxia on the expression of fractalkine induced by interferon-gamma (IFN-gamma) in endothelial cells. Human umbilical vein endothelial cells were cultured, and the stimulation of the cells with IFN-gamma was found to induce the expression of fractalkine. Hypoxia inhibited the expression of fractalkine mRNA and protein by IFN-gamma, and this effect was observed with concomitant increase in VEGF expression. Desferrioxamine, an iron chelator that mimics hypoxia in vitro, also inhibited the fractalkine production induced by IFN-gamma. Hypoxia did not affect the degradation of fractalkine mRNA. The inhibition of fractalkine expression by hypoxia was reversed on returning the cultures to reoxygenation condition. Inhibition of IFN-induced fractalkine expression by hypoxia was not affected by the presence of a radical scavenger, N-acetyl-L-cysteine, and the involvement of reactive oxygen species may be excluded. Inhibition of fractalkine expression by hypoxia may be involved in the pathophysiology of ischemic diseases.

15-Deoxy-delta 12,14-prostaglandin J2 inhibits the expression of granulocyte-macrophage colony-stimulating factor in endothelial cells stimulated with lipopolysaccharide.

Granulocyte-macrophage colony-stimulating factor (GM-CSF), one of major hematopoietic growth factors, activates mature leukocytes. GM-CSF is produced by endothelial cells stimulated with lipopolysaccharide (LPS), and the LPS-induced GM-CSF production may play an important role in the activation of neutrophils on the endothelial surface. 15-Deoxy-delta 12,14-prostaglandin J2 (15d-PGJ2) is a ligand for peroxisome proliferator-activated receptor-gamma (PPAR-gamma) and modulates inflammatory reactions by regulating the expression of various genes. We studied the effect of 15d-PGJ2 on the LPS-induced GM-CSF expression in endothelial cells. Human umbilical vein endothelial cells (HUVEC) were cultured and the expressions of GM-CSF mRNA and protein were analyzed by reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. 15d-PGJ2 inhibited the LPS-induced GM-CSF expression in a concentration-dependent manner; but ciglitazone, another agonist for PPAR-gamma, had no effect. This suggests that 15d-PGJ2 inhibits GM-CSF expression through a mechanism unrelated to PPAR-gamma. 15d-PGJ2 induced, by itself, the expression of interleukin-8, a potent proinflammatory chemokine, in HUVEC. 15d-PGJ2 may regulate inflammatory reactions by controlling the balance of various cytokines.

15-deoxy-delta(12,14)-prostaglandin J2 inhibits IFN-gamma-induced galectin-9 expression in cultured human umbilical vein endothelial cells.

BACKGROUND: Galectin-9 is involved in chemotaxis and adhesion of eosinophils, and is induced in vascular endothelial cells by interferon-gamma (IFN-gamma). 15-deoxy-delta(12,14)-prostaglandin J(2) (15d-PGJ(2)) is a ligand for peroxisome proliferator-activated receptor-gamma (PPAR-gamma), and known to modulate the expression of various genes. METHODS: We have studied the effect of 15d-PGJ(2) on the IFN-gamma-induced galectin-9 expression in human umbilical vein endothelial cells (HUVEC) in culture. RESULTS: 15d-PGJ(2) inhibited the IFN-gamma-induced galectin-9 expression in a PPAR-gamma-independent manner, and also inhibited the adhesion of EoL-1 cells to an HUVEC monolayer treated with IFN-gamma. 15d-PGJ(2) partially inhibited IFN-gamma-induced phosphorylation of STAT-1 in HUVEC. CONCLUSIONS: 15d-PGJ(2) may regulate inflammatory reactions through the inhibition of galectin-9 expression.

15-Deoxy-D12,14-prostaglandin J2 inhibits CX3CL1/fractalkine expression in human endothelial cells.

Peroxisome proliferator-activated receptor-gamma (PPAR-gamma)is a member of nuclear hormone receptor superfamily, and is knownto play a role in various biological processes including inflammatoryresponses and adipocyte differentiation. CX3CL1/fractalkineis a potent agonist for chemotaxis and adhesion of monocytes and lymphocytes. Endothelial cells produce fractalkine when stimulated with cytokinessuch as interleukin-1 (IL-1), tumour necrosis factor-alpha andinterferon-gamma (IFN-gamma). We herein report that 15-deoxy-n12,14 -prostaglandinJ2 (15d-PGJ2), a PPAR-gamma agonist,inhibits the expression of fractalkine induced by IFN-gamma orIL-1beta in human endothelial cells. Agonist for PPAR-alpha (WY14643)or PPAR-gamma (ciglitazone) did not inhibit the cytokine-inducedfractalkine expression, and the effect of 15d-PGJ2 maybe independent of PPAR. 15-Deoxy-D12,14 prostaglandinJ2 also inhibited the adhesion of blood mononuclear cellsto endothelial monolayers treated with IFN-gamma or IL-1beta. The data suggest that 15d-PGJ2 regulates inflammatoryreactions, at least in part, through the inhibition of fractalkineexpression and leucocyte traffic through the endothelium.

Interferon-gamma stimulates the expression of galectin-9 in cultured human endothelial cells.

Galectin-9 is a member of the galectin family and has been identified as an eosinophil chemoattractant produced by activated T lymphocytes. Vascular endothelial cells play an important role in the initial step of eosinophil recruitment and activation in immune and inflammatory responses. We have addressed the stimulation of galectin-9 expression in endothelial cells. Galectin-9 was detected in membrane and cytosolic fractions of human umbilical vein endothelial cells stimulated with interferon-gamma (IFN-gamma). IFN-gamma also enhanced the adhesion of human eosinophilic leukemia-1 cells to endothelial monolayers, and it was inhibited by the presence of lactose. Interleukin-4, which induces eotaxin expression, did not affect the expression of galectin-9. The in situ endothelium from patients with inflammatory diseases was found to express galectin-9. IFN-gamma-induced production of galectin-9 by endothelial cells may play an important role in immune responses by regulating interactions between the vascular wall and eosinophils.

Platelet-activating factor enhances the expression of vascular endothelial growth factor in normal human astrocytes.

Vascular endothelial growth factor (VEGF) is a potent and specific mitogen for vascular endothelial cells. To examine whether platelet-activating factor (PAF) induces the expression of VEGF in human astrocytes, we stimulated cultured normal astrocytes with PAF and performed semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) or real-time quantitative PCR for VEGF mRNA and enzyme-linked immunosorbent assay for VEGF protein. PAF increased the expression of VEGF in astrocytes in time- and dose-dependent manners. After 24-h stimulation, 10 nM PAF increased the levels of VEGF protein in astrocyte-conditioned medium by 1.3-fold. When the cells were subjected to hypoxia, the PAF-induced production of VEGF was enhanced by 6.7-fold as compared to the unstimulated cells incubated under normoxia. Dexamethasone was found to inhibit the enhanced VEGF production in response to the stimulation with PAF under hypoxia. We conclude that PAF induces VEGF gene expression in human astrocytes, and the PAF-induced increase in the expression of VEGF may modulate nervous tissue injury due to hypoxia.