Role of non-macrophage cell-derived HMGB1 in oxaliplatin-induced peripheral neuropathy and its prevention by the thrombin/thrombomodulin system in rodents: negative impact of anticoagulants.

BACKGROUND: Macrophage-derived high mobility group box 1 (HMGB1), a damage-associated molecular pattern (DAMP) protein, plays a key role in the development of chemotherapy-induced peripheral neuropathy (CIPN) caused by paclitaxel in rodents. Endothelial thrombomodulin (TM) promotes thrombin-induced degradation of HMGB1, and TMα, a recombinant human soluble TM, abolishes peripheral HMGB1-induced allodynia in mice. We thus examined whether HMGB1, particularly derived from macrophages, contributes to oxaliplatin-induced neuropathy in mice and analyzed the anti-neuropathic activity of the TM/thrombin system. METHODS: CIPN models were created by the administration of oxaliplatin in mice and rats, and the nociceptive threshold was assessed by von Frey test or paw pressure test. Macrophage-like RAW264.7 cells were stimulated with oxaliplatin in vitro. Proteins were detected and/or quantified by Western blotting, immunostaining, or enzyme-linked immunosorbent assay. RESULTS: Intraperitoneal administration of an anti-HMGB1-neutralizing antibody (AB) at 1 mg/kg prevented the oxaliplatin-induced allodynia in mice and rats. Antagonists of Toll-like receptor (TLR) 4, receptor for advanced glycation end products (RAGE) and CXCR4 among the HMGB1-targeted pro-nociceptive receptors, also mimicked the anti-neuropathic activity of AB in mice. Macrophage accumulation in the sciatic nerve was observed in mice treated with paclitaxel, but not oxaliplatin, and neither macrophage depletion nor inhibitors of macrophage activation affected oxaliplatin-induced allodynia. Oxaliplatin was 10- to 100-fold less potent than paclitaxel in releasing HMGB1 from macrophage-like RAW264.7 cells. Like AB, TMα at 10 mg/kg prevented the oxaliplatin-induced allodynia in mice as well as rats, an effect abolished by argatroban at 10 mg/kg, a thrombin inhibitor. The anti-neuropathic activity of TMα in oxaliplatin-treated mice was suppressed by oral anticoagulants such as warfarin at 1 mg/kg, dabigatran at 75 mg/kg, and rivaroxaban at 10 mg/kg, but not antiplatelet agents such as aspirin at 50 mg/kg and clopidogrel at 10 mg/kg. Repeated administration of the anticoagulants gradually developed neuropathic allodynia and elevated plasma HMGB1 levels in mice treated with a subeffective dose of oxaliplatin. CONCLUSIONS: Our data thus suggests a causative role of HMGB1 derived from non-macrophage cells in oxaliplatin-induced peripheral neuropathy and a thrombin-dependent anti-neuropathic activity of exogenous TMα and, most probably, endogenous TM.

Electroacupuncture most effectively elicits depressor and bradycardic responses at 1 Hz in humans.

PURPOSE: Acupuncture stimulation is known to act on the autonomic nervous system and elicits depressor and bradycardic effects. However, previous studies on humans did not conduct quantitative analyses on optimal acupuncture conditions such as the stimulation frequency and duration to achieve maximum depressor and bradycardic effects. The aim of the present study was to investigate the effects of varying stimulation frequencies of electroacupuncture on time-dependent changes in blood pressure and heart rate in humans. METHODS: Twelve healthy volunteers participated in the study. An acupuncture needle was inserted at the Ximen acupoint (PC4 according to WHO nomenclature), located at the anterior aspect of the forearm. An electrical stimulation was delivered through the acupuncture needle at an intensity of 1 V, pulse width of 5 ms, and stimulation frequencies of 0.5, 1, 5, and 10 Hz in a random order. The duration of electroacupuncture was 6 min, during which blood pressure and heart rate responses were monitored. RESULTS: Group-averaged data indicated that 1-Hz electroacupuncture decreased blood pressure and heart rate. Blood pressure was significantly decreased from the prestimulation baseline value of 86.6 ± 2.9 to 81.4 ± 2.3 mmHg during 4-6 min of 1-Hz electroacupuncture (mean ± SE, P < 0.01). Heart rate was also significantly decreased (from 66.2 ± 2.0 to 62.7 ± 1.7 beats/min, P < 0.01). CONCLUSIONS: These results provide fundamental evidence that bradycardiac and depressor responses are effectively produced by electrical acupuncture in humans.

Effects of Standing after a Meal on Glucose Metabolism and Energy Expenditure.

In the past decade, university students have become more sedentary. A sedentary lifestyle is associated with an increased risk of obesity and cardiovascular disease. Methods that decrease sedentary lifestyles, such as the use of standing desks to increase physical activity, have been extensively examined. However, the effects of postprandial standing and sitting on energy metabolism have not yet been compared. Therefore, the present study investigated the effects of standing after a meal on energy expenditure and glucose metabolism. Ten males participated in the present study. The experiment was initiated with 300 g of rice ingested as a carbohydrate load. The subjects maintained a standing or sitting position for 120 min after the meal. Energy expenditure was calculated from VO2 and VCO2 using the indirect calorimetry method. Glucose metabolism was assessed by measuring blood glucose levels and the exogenous glucose metabolic rate. Energy expenditure through standing after eating was approximately 0.16 ± 0.08 kcal/min higher than that through sitting. Blood glucose dynamics did not significantly differ between the standing and sitting positions. Furthermore, no significant differences were observed in the dynamics of the exogenous glucose metabolic rate between the standing and sitting positions. Standing for 2 h after a meal increased energy expenditure by 10.7 ± 4.6% without affecting glucose metabolism.

Administration of pigment epithelium-derived factor inhibits left ventricular remodeling and improves cardiac function in rats with acute myocardial infarction.

Oxidative stress and inflammation are involved in cardiac remodeling after acute myocardial infarction (AMI). We have found that pigment epithelium-derived factor (PEDF) inhibits vascular inflammation through its anti-oxidative properties. However, effects of PEDF on cardiac remodeling after AMI remain unknown. We investigated whether PEDF could inhibit left ventricular remodeling and improve cardiac function in rats with AMI. AMI was induced in 8-week-old Sprague-Dawley rats by ligation of the left ascending coronary artery. Rats were treated intravenously with vehicle or 10 µg PEDF/100 g b.wt. every day for up to 2 weeks after AMI. Each rat was followed until 16 weeks of age. PEDF levels in infarcted areas and serum were significantly decreased at 1 week after AMI and remained low during the observational periods. PEDF administration inhibited apoptotic cell death and oxidative stress generation around the infarcted areas at 2 and 8 weeks after AMI. Further, PEDF injection suppressed cardiac fibrosis by reducing transforming growth factor-ß and type III collagen expression, improved left ventricular ejection fraction, ameliorated diastolic dysfunction, and inhibited the increase in left ventricular mass index at 8 weeks after AMI. The present study demonstrated that PEDF could inhibit tissue remodeling and improve cardiac function in AMI rats. Substitution of PEDF may be a novel therapeutic strategy for cardiac remodeling after AMI.

Changes in salivary antimicrobial peptides, immunoglobulin A and cortisol after prolonged strenuous exercise.

The aim of the present study was to examine whether amount of oral antimicrobial components, human ß-defensin-2 (HBD-2), cathelicidin (LL-37), and immunoglobulin A (IgA), might be affected by prolonged strenuous exercise. Ten young male volunteers either exercised on recumbent ergometer at 75% [Formula: see text] for 60 min (exercise session) or sat quietly (resting session). Saliva samples were obtained at 60-min intervals during sessions for measurements of saliva antimicrobial components (HBD-2, LL-37, and IgA), saliva cortisol and osmolality. Saliva flow rate was decreased and saliva osmolality was increased during the 60-min exercise. Saliva HBD-2 and LL-37 concentrations and secretion rates were increased during and after the exercise, whereas saliva IgA concentration and secretion rates were decreased after the exercise. Saliva cortisol was increased during and after the exercise. The areas under the curve of the time courses of saliva levels of HBD-2 and LL-37 were negatively correlated with those of cortisol levels in saliva. The present findings suggested that a single bout of prolonged strenuous exercise caused a transient increase in the oral HBD-2 and LL-37 levels.

Effects of pre-exercise acupuncture stimulation on heart rate response during short-duration exercise.

BACKGROUND: The purpose of the present study was to investigate the effects of bradycardia induced by pre-exercise acupuncture on heart rate responses during short-duration exercise. METHODS: A total of 29 healthy subjects underwent two protocols: protocol 1 assessed the effects of manual acupuncture on heart rate response during rest, and protocol 2 tested the hypothesis that the bradycardic effects induced by pre-exercise acupuncture continue during low- and high-intensity exercise. Their average age, height, weight, and body mass index were 21.2 ± 2.0 years, 167.2 ± 8.8 cm, 63.8 ± 12.8 kg, and 22.7 ± 3.5 kg/m2, respectively. In acupuncture stimulations for protocols 1 and 2, an acupuncture needle was inserted into the lower leg and manual acupuncture stimulation was performed at 1 Hz. RESULTS: In protocol 1 (resting condition), acupuncture stimulation induced a bradycardic response, which continued for 4 min after the cessation of acupuncture stimulation (p < 0.05). In protocol 2, the bradycardic response induced by pre-exercise acupuncture stimulation remained during low-intensity exercise and in the beginning of high-intensity exercise performed immediately after the cessation of acupuncture stimulation (p < 0.05). However, the effects disappeared when post-acupuncture exercise was performed when the heart rate was approximately 140 beats/min during high-intensity exercise. The rating of perceived exertion after exercise differed significantly between the acupuncture stimulation task (7.9 ± 1.6) and no-stimulation task (8.5 ± 2.0) (p = 0.03) only in the low intensity group. CONCLUSION: This study may provide new insights into the effect of acupuncture stimulation on psycho-physiological conditions during exercise.

Isolation and characterization of a virus (CvV-BW1) that infects symbiotic algae of Paramecium bursaria in Lake Biwa, Japan.

BACKGROUND: We performed an environmental study of viruses infecting the symbiotic single-celled algae of Paramecium bursaria (Paramecium bursaria Chlorella virus, PBCV) in Lake Biwa, the largest lake in Japan. The viruses detected were all Chlorella variabilis virus (CvV = NC64A virus). One of them, designated CvV-BW1, was subjected to further characterization. RESULTS: CvV-BW1 formed small plaques and had a linear DNA genome of 370 kb, as judged by pulsed-field gel electrophoresis. Restriction analysis indicated that CvV-BW1 DNA belongs to group H, one of the most resistant groups among CvV DNAs. Based on a phylogenetic tree constructed using the dnapol gene, CvV was classified into two clades, A and B. CvV-BW1 belonged to clade B, in contrast to all previously identified virus strains of group H that belonged to clade A. CONCLUSIONS: We conclude that CvV-BW1 composes a distinct species within C. variabilis virus.

Effects of aquatic exercise training using water-resistance equipment in elderly.

To prevent falls in Japan, both gait and resistance training of the lower extremities are recommended. However, resistance training for the elderly induces muscle damage. Recently, aquatic exercise using water buoyancy and resistance have commonly been performed by the elderly. We have now produced new water-resistance equipment. The purpose of the present study was to evaluate the efficacy of aquatic exercise training using the new equipment for the elderly. Subjects were divided into two groups: a resistance group of 12 subjects (using water-resistance equipment) and a non-resistance group of eight subjects (without the equipment). The aquatic exercise training was 90 min, three times per week for 8 weeks, and mostly consisted of walking. All subjects underwent anthropometric measurements, physical performance testing, and profile of mood states (POMS). Significant improvements were observed in muscle strength in plantar flexion, and the timed up and go test (TUG) in both groups. Additionally, 10-m obstacle walking and 5-m maximum walking speed and length with eye-open were significantly improved in the resistance group. Also, a low negative correlation was found between the degree of change in TUG and POMS (tension and anxiety) scores in the resistance group. As it became easier to maintain posture, stand, and move, tension and anxiety in everyday life were alleviated with improvement of strength of the lower extremities and balance function. The present aquatic exercise training using water-resistance equipment may be used by the elderly to improve balance and walking ability, which are associated with the prevention of falls.

Low Frequency Severe-Intensity Interval Training Markedly Alters Respiratory Compensation Point During Incremental Exercise in Untrained Male.

This study investigated the effect of low-frequency severe-intensity interval training on the respiratory compensation point (RCP) during incremental exercise test. Eighteen healthy males (age; 20.7 ± 2.2 years, range 18 to 29 years, height; 174.0 ± 5.6 cm, weight; 68.8 ± 13.5 kg) were randomly assigned to an interval training group or a control group. Interval training was conducted once weekly for 3 months. Each session consisted of three bouts of bicycle ergometer exercise at 80% maximum work rate until volitional fatigue. Before (baseline) and after the 3-month intervention, incremental exercise test was performed on a bicycle ergometer for determination of ventilatory threshold (VT), RCP, and peak oxygen consumption (V̇O 2 peak). The training program resulted in significant increases of V̇O 2 peak (+ 14%, p < 0.001, η p 2 = 0.437), oxygen consumption (V̇O 2) at VT (+ 18%, p < 0.001, η p 2 = 0.749) and RCP (+ 15%, p = 0.03, η p 2 = 0.239) during incremental exercise test in the training group. Furthermore, a significant positive correlation was observed between the increase in V̇O 2 peak and increase in V̇O 2 at RCP after intervention (r = 0.87, p = 0.002) in the training group. Tidal volumes at VT (p = 0.04, η p 2 = 0.270) and RCP (p = 0.01, η p 2 = 0.370) also increased significantly after intervention compared to baseline. Low-frequency severe-intensity interval training induced a shift in RCP toward higher work rate accompanied by higher tidal volume during incremental exercise test.

A case of prostate stromal sarcoma involving the rectum.

Sarcomas and related proliferative lesions of the specialized stroma of the prostate are very rare and have been classified into prostate stromal sarcoma (PSS) and prostatic stromal tumor of uncertain malignant potential based on histology. We herein describe a case of PSS. A 40-year-old male presented at a hospital with urinary distention. Magnetic resonance imaging revealed a large prostate mass, and the diagnosis was prostate sarcoma of uncertain differentiation by ultrasound-guided needle biopsy. Total pelvic exenteration was performed and a pathological diagnosis of PSS was ultimately reached. Ten months later, there have been no signs of metastasis or recurrence.

HbA1c levels measured by enzymatic assay during off-site health checkups are lower than those measured by on-site HPLC assay.

HbA1c is widely used as a therapeutic target marker and as a diagnostic marker for diabetes mellitus. This has led to an increasing frequency of HbA1c measurements in current health checkups throughout Japan. In the present study, we compared the HbA1c levels measured by an enzymatic assay (EA-HbA1c) off-site during health checkups with the HbA1c levels measured by on-site ion-exchange high-performance liquid chromatography (HPLC; HPLC-HbA1c) in a hospital. A total of 96 individuals (53 males and 43 females; age, 68.9 ± 8.4 years old; 70 diabetic and 26 non-diabetic individuals) whose HbA1c levels were measured by both the methods listed above were included in the study. Since no HPLC-HbA1c levels were measured on the day of the health checkup, HPLC-HbA1c levels were estimated using HPLC-HbA1c levels measured before and after the health checkup. A significant correlation of HbA1c levels was observed between the two groups (R = 0.973; p < 0.001). However, EA-HbA1c levels measured off-site during health checkups are lower than estimated HPLC-HbA1c levels measured on-site (6.37 ± 0.75% vs. 6.69 ± 0.75%; p < 0.001). Since lower EA-HbA1c levels measured during health checkups, which diverged from on-site measurements, may lead to underestimating diabetes mellitus, accurate measurement of HbA1c is required irrespective of the measuring method. Further investigation of the cause of falsely low EA-HbA1c levels and the strategy for reconciling HbA1c to reflect plasma glucose accurately are warranted.

Increase in diastolic blood pressure induced by fragrance inhalation of grapefruit essential oil is positively correlated with muscle sympathetic nerve activity.

Fragrance inhalation of essential oils is widely used in aromatherapy, and it is known to affect blood pressure (BP) and heart rate (HR) via autonomic control of circulation. In this study, we aimed to test the hypothesis that the changes in hemodynamics with fragrance inhalation were observed along with changes in muscle sympathetic nerve activity (MSNA). In study 1, thirteen healthy men were exposed to fragrance stimulation of grapefruit essential oil for 10 min, and BP, HR, and MSNA were continuously measured. In study 2, another nine healthy men were exposed to the same fragrance stimulation; responses in BP and HR were continuously measured, and plasma noradrenaline and cortisol concentrations were determined. We found that diastolic BP increased significantly during fragrance inhalation, while the other variables remained unchanged in both studies. Although MSNA burst frequency, burst incidence, and total activity remained unchanged during fragrance inhalation, we found a significant linear correlation between changes in diastolic BP in the last 5 min of fragrance inhalation and changes in MSNA burst frequency. The plasma cortisol concentration decreased significantly at 10 min of fragrance inhalation, though the noradrenaline concentration remained unchanged. These results suggest, for the first time, that changes in BP with fragrance inhalation of essential oil are associated with changes in MSNA even with decreased stress hormone.

Usefulness of the SAGE score to predict elevated values of brachial-ankle pulse wave velocity in Japanese subjects with hypertension.

The score based on the office systolic blood pressure, age, fasting blood glucose level, and estimated glomerular filtration rate (SAGE score) has been proposed as a useful marker to identify elevated values of carotid-femoral pulse wave velocity (PWV). The present cross-sectional study was conducted to examine whether the SAGE score is also a useful marker to identify subjects with elevated brachial-ankle PWV values in Japanese subjects with hypertension. We measured the brachial-ankle PWV and calculated the SAGE score in a total of 1019 employees of a Japanese company with hypertension and 817 subjects with hypertension derived from a multicenter study cohort. The analyses in this study were based on data from these two study groups as well as on a composite population of the two (n = 1836). The receiver operating characteristic curve analysis showed that the area under the curve to identify subjects with brachial-ankle PWV values of ≥1800 cm/s was over 0.70 in each of the three study groups. Even after adjustments, a SAGE score ≥7 had a significant odds ratio for identifying subjects with brachial-ankle PWV values ≥1800 cm/s in the 1836 study subjects from the composite occupational and multicenter study cohort (odds ratio = 2.1, 95% confidence interval = 1.4-3.0, P < 0.01). Thus, in Japanese subjects with hypertension, the SAGE score may be a useful marker for identifying subjects with elevated brachial-ankle PWV values.

Acupoint dependence of depressor and bradycardic responses elicited by manual acupuncture stimulation in humans.

The cardiovascular effects of the autonomic nervous system (ANS) are modulated by inputs from peripheral sensors and other brain regions. However, it currently remains unknown whether the manual acupuncture (MA) stimulation of different acupuncture points evokes different responses by the heart and vasculature, a phenomenon known as "site specificity". Sixty healthy subjects were randomly divided into a control group and MA stimulation groups at the lower leg, ear, abdomen, and forearm. MA was performed at 1 Hz for 2 min. A depressor response was observed only in the lower leg stimulation group, in which mean blood pressure significantly decreased from 83.4 ± 10.1 to 80.9 ± 11.7 mmHg (p < 0.003). A bradycardic response was elicited in all MA stimulation groups. There was no significant differences in the magnitude of the bradycardic response between groups. MA-induced cardiovascular responses, which may be mediated by the modulation of ANS, differ depending on acupuncture points.

Effects of Lactotripeptide Supplementation on Tele-Monitored Home Blood Pressure and on Vascular and Renal Function in Prehypertension　- Randomized, Double-Blind, Placebo-Controlled, Cross-Over Study.

Background: This randomized, double-blind, placebo-controlled, cross-over study was conducted to examine the effects of lactotripeptide supplementation on 7-day mean tele-monitored home blood pressure (BP), and also on the markers of vascular function and renal damage in Japanese subjects with prehypertension. Methods and Results: A total of 26 subjects with prehypertension were randomly allocated to receive the active product (lactotripeptide tablet) or a placebo tablet for 8 weeks each in a cross-over manner. Urinary liver-type fatty acid-binding protein-to-creatine ratio (UFABPCR) and vascular function were measured at the end of each intervention. Home systolic and diastolic BP at the end of the lactotripeptide supplementation period was significantly lower than that at the end of the placebo period (P<0.05). On mixed linear model analysis there was a significant difference in the change in home diastolic BP after intervention between the 2 interventions (P=0.04). UFABPCR was significantly lower at the end of the lactotripeptide intervention period than at the end of the placebo period (P<0.05). Conclusions: The beneficial effect of lactotripeptide supplementation on 7-day mean tele-monitored home BP was confirmed in Japanese subjects with prehypertension. In addition, this intervention also seemed to have a protective effect against the progression of renal function decline.

Effect of short-term colchicine treatment on endothelial function in patients with coronary artery disease.

BACKGROUND: Inflammation is associated with endothelial dysfunction and plays an important role in the pathogenesis and development of cardiovascular diseases. It has been shown that colchicine, an anti-inflammatory drug, improves the cardiovascular outcome in patients with cardiovascular disease. The purpose of this study was to evaluate the short-term effect of low-dose colchicine on endothelial function in patients with coronary artery disease (CAD). METHODS: This was a double-blind, randomized, placebo-controlled, crossover-within-subject clinical trial. A total of 28 patients with CAD received low-dose colchicine (0.5 mg/day) or a placebo for 7 days with a washout period of at least 14 days. Flow-mediated vasodilation (FMD) and serum concentrations of high-sensitivity C-reactive protein (hs-CRP) were measured after the 7-day treatment with colchicine or the placebo. RESULTS: The serum concentration of hs-CRP was significantly decreased after administration of colchicine compared with that after administration of the placebo [median (interquartile range): 0.04 (0.02-0.08) mg/dL vs. 0.07 (0.04-0.11) mg/dL, P = 0.003], while there was no significant difference in FMD between the treatments [median (interquartile range): 3.1% (1.5-5.3%) vs. 3.3% (1.9-5.2%), P = 0.384]. Colchicine, however, significantly improved FMD in coronary artery disease patients with white blood cell (WBC) counts of ≥7500 WBC/mm3 [median (interquartile range): 3.3% (2.1-6.6%) vs. 2.0% (1.4-3.8%), P = 0.043]. CONCLUSIONS: Administration of low-dose colchicine did not improve endothelial function in patients with CAD, but exploratory analysis suggested that endothelial function is significantly improved in patients with leukocyte activation.

Flow-mediated vasodilation as a diagnostic modality for vascular failure.

Vascular endothelial dysfunction represents an initial step of "vascular failure," which we have recently proposed as a comprehensive syndrome of failed vascular functions that extends from risk factors to established atherosclerotic disease. The early detection of vascular failure is essential in order to appropriately intervene and prevent its progression. Many efforts have been made to assess vascular endothelial function, and one of the most promising methods is the measurement of endothelium-dependent flow-mediated vasodilation (FMD) using high-frequency ultrasonographic imaging and transient occlusion of the brachial artery. The reactive hyperemia caused by the transient brachial arterial occlusion induces the release of local nitric oxide, resulting in vasodilation that can be quantified as an index of vasomotor function. The noninvasive nature of this technique allows repeated measurements over time to study the effectiveness of various interventions that may affect vascular health. Although there are technical and interpretive limitations of this technique, FMD-guided therapeutic approaches for vascular failure should contribute to the improvement of cardiovascular mortality and morbidity.

Effects of walking in water on gut hormone concentrations and appetite: comparison with walking on land.

The effects of water exercise on gut hormone concentrations and appetite currently remain unclear. The aim of the present study was to investigate the effects of treadmill walking in water on gut hormone concentrations and appetite. Thirteen men (mean ± s.d. age: 21.6 ± 2.2 years, body mass index: 22.7 ± 2.8 kg/m2, peak oxygen uptake (VO2peak): 49.8 ± 7.8 mL/kg per min) participated in the walking in water and on land challenge. During the study period, ratings of subjective feelings of hunger, fullness, satiety and motivation to eat were reported on a 100-mm visual analog scale. A test meal was presented after walking, and energy intake (EI) was calculated. Blood samples were obtained during both trials to measure glucagon-like peptide-1 (GLP-1), peptide YY (PYY) and acylated ghrelin (AG) concentrations. Hunger scores (How hungry do you feel?) were significantly lower during the water trial than during the land trial (P < 0.05). No significant differences were observed in EI between water and land trials. GLP-1 concentrations were significantly higher in the water trial than in the land trial (P < 0.05). No significant differences were observed in PYY concentrations between water and land trials. AG concentrations were significantly lower in the water trial than in the land trial (P < 0.01). In conclusion, changes in gut hormone concentrations during walking in water contribute to the exercise-induced suppression of appetite and provide novel information on the influence of walking in water on the acute regulation of appetite.

Administration of pigment epithelium-derived factor (PEDF) inhibits cold injury-induced brain edema in mice.

Brain edema is the most life-threatening complication that occurs as a result of a number of insults to the brain. However, its therapeutic options are insufficiently effective. We have recently found that administration of pigment epithelium-derived factor (PEDF) inhibits retinal hyperpermeability in rats by counteracting biological effects of vascular endothelial growth factor (VEGF). In this study, we investigated whether PEDF could inhibit cold injury-induced brain edema in mice. Cold injury was induced by applying a pre-cooled metal probe on the parietal skull. VEGF and its receptor Flk-1 gene and/or protein expressions were up-regulated in the cold-injured brain. Cold injury induced brain edema, which was reduced by intraperitoneal injection of VEGF antibodies (Abs) or apocynin, an inhibitor of NADPH oxidase. PEDF mRNA and protein levels were up-regulated in response to cold injury. PEDF dose-dependently inhibited the brain edema, whose effect was neutralized by simultaneous treatments with anti-PEDF Abs. Although VEGF and Flk-1 gene and/or protein expressions were not suppressed by PEDF, PEDF or anti-VEGF Abs inhibited the cold injury-induced NADPH oxidase activity in the brain. Further, PEDF treatment inhibited activation of Rac-1, an essential component of NADPH oxidase in the cold-injured brain, while it did not affect mRNA levels of gp91phox, p22phox, or Rac-1. These results demonstrate that PEDF could inhibit the cold injury-induced brain edema by blocking the VEGF signaling to hyperpermeability through the suppression of NADPH oxidase via inhibition of Rac-1 activation. Our present study suggests that PEDF may be a novel therapeutic agent for the treatment of brain edema.