Excess intracellular ATP causes neuropathic pain following spinal cord injury.

Intractable neuropathic pain following spinal cord injury (NP-SCI) reduces a patient's quality of life. Excessive release of ATP into the extracellular space evokes neuroinflammation via purinergic receptor. Neuroinflammation plays an important role in the initiation and maintenance of NP. However, little is known about whether or not extracellular ATP cause NP-SCI. We found in the present study that excess of intracellular ATP at the lesion site evokes at-level NP-SCI. No significant differences in the body weight, locomotor function, or motor behaviors were found in groups that were negative and positive for at-level allodynia. The intracellular ATP level at the lesion site was significantly higher in the allodynia-positive mice than in the allodynia-negative mice. A metabolome analysis revealed that there were no significant differences in the ATP production or degradation between allodynia-negative and allodynia-positive mice. Dorsal horn neurons in allodynia mice were found to be inactivated in the resting state, suggesting that decreased ATP consumption due to neural inactivity leads to a build-up of intracellular ATP. In contrast to the findings in the resting state, mechanical stimulation increased the neural activity of dorsal horn and extracellular ATP release at lesion site. The forced production of intracellular ATP at the lesion site in non-allodynia mice induced allodynia. The inhibition of P2X4 receptors in allodynia mice reduced allodynia. These results suggest that an excess buildup of intracellular ATP in the resting state causes at-level NP-SCI as a result of the extracellular release of ATP with mechanical stimulation.

Relationship Between Infarct Volume and Prothrombin Time-International Normalized Ratio in Ischemic Stroke Patients With Nonvalvular Atrial Fibrillation.

BACKGROUND: In Japan, warfarin treatment at prothrombin time-international normalized ratio (PT-INR) of 1.60-2.60 is recommended for elderly patients with nonvalvular atrial fibrillation (NVAF). But it remains unknown whether PT-INR 1.60-1.99 has a similar effect on stroke severity as a value >2.0. The purpose of this study was to clarify the association between infarct volume and PT-INR levels.Methods and Results:The 180 patients (mean age, 76 years [SD, 10 years], 53% male) selected from 429 consecutive ischemic stroke patients admitted within 48 h of onset between 2004 and 2014 with NVAF were included. We classified them into 4 groups according to their PT-INR values on admission: no warfarin (NW), 129 patients; PT-INR <1.60 (poor control: PC), 29 patients; PT-INR 1.60-1.99 (low-intensity control: LC), 14 patients; and PT-INR ≥2.00 (high-intensity control: HC), 8 patients. Median (interquartile range: IQR) of infarct volume was 55 mL (IQR 14-175) in the NW, 42 mL (IQR 27-170) in the PC, 36 mL (IQR 6-130) in the LC, and 11 mL (IQR 0-39) in the HC groups. The infarct volume of the HC group was significantly smaller than in the other 3 groups, but no difference existed between the LC and PC groups or the LC and NW groups. CONCLUSIONS: Warfarin control at PT-INR of 1.60-1.99 is not effective for reducing the severity of ischemic stroke in NVAF patients.

Hemodynamic response during standing test after blood donation can predict the late phase vasovagal reaction.

A major complication of blood donation is vasovagal reaction (VVR) with or without syncope. VVR occurs not only in the early phase, but also in the late phase after blood donation. We previously reported the hemodynamic characteristics of blood donors susceptible to early phase VVR. In the present study, we investigated the hemodynamic characteristics of those who developed late VVR. Ninety-six healthy volunteers donating 400 ml of whole blood were studied. After asking about their physical condition or routine questions for blood donation, blood pressure (BP) and heart rate (HR) were recorded while the donors were kept standing up for 3 min before and after blood collection. Questionnaires were distributed to all donors for reporting late VVR symptoms within 24 h. Those with younger age and lower diastolic blood pressure were more susceptible to late VVR (both p < 0.05). Furthermore, we identified the increase in HR during the standing test after blood collection as a good predictor of late VVR (odds ratio 1.063, 95 % CI 1.005-1.124; p = 0.031). Also, analysis of questions asked before donation revealed that significantly more donors considered themselves as sensitive to pain in the late VVR group (Odds ratio 0.070, 95 % CI 0.008-0.586; p = 0.014). Excessive HR response to standing after blood collection and subjective sensitivity to pain as well as younger age and lower diastolic BP may be useful to detect donors at high risk for late VVR.

Echogenicity of medium-to-large carotid plaques predicts future vascular events.

BACKGROUND: Although the echolucent plaque in carotid stenosis is associated with future ischemic stroke, the predictive value of echogenicity in small and medium size carotid plaques on vascular events has not been thoroughly examined. Thus, we prospectively tested the hypothesis that plaque echogenicity of carotid atheroma can predict the future total cardiovascular events in patients with vascular risk factors. METHODS: Ultrasound assessment of carotid intima-media complex thickness (IMT) and plaque echogenicity using integrated backscatter (IBS) analysis was performed in 596 patients aged 40 or more, with any history of vascular events or with at least 1 risk factor, who were enrolled between 2001 and 2006 in the Osaka Follow-up Study for Carotid Atherosclerosis, part 2 (OSACA2). We followed the incidence of total cardiovascular events including cerebrovascular events, coronary heart disease (CHD), and peripheral artery disease (PAD) for 6.4 years. We divided the patients into two groups according to the IBS index above (echorich plaques) and under (echolucent plaque) the median value, and calculated the hazard ratios (HR) of the echolucent group compared with the echogenic group in the risk of cardiovascular events. RESULTS: Among 596 patients, carotid stenosis was found only in 87 patients. During the follow-up period, we observed 121 cardiovascular events including 63 cerebrovascular events, 45 CHD cases, and 13 PAD cases. The patients with incident cardiovascular events had larger plaque thickness and lower IBS index than those without incident vascular events. The relative risk of vascular events for echolucent versus echorich plaques was 1.45 (95% confidence interval [CI] 0.99-2.13, p = 0.058) after adjustment for risk factors and plaque thickness. In patients with plaque size above the median value (>2.1 mm), the relative risk of vascular events for echolucent plaques was 1.72 (95% CI 1.06-2.85, p = 0.029), but this association was not observed in patients with plaque size <2.0 mm. CONCLUSIONS: The association between echogenicity of carotid plaque and incident vascular events is dependent on the plaque size. Echolucent medium-to-large plaques, but not small plaques, are associated with the risk of future total cardiovascular events. This finding suggests that measurement of echolucency in medium-to-large carotid plaques may improve selection of patients at high risk for total vascular events.

Campylobacter jejuni infection suppressed Cl⁻ secretion induced by CFTR activation in T-84 cells.

Campylobacter jejuni causes foodborne disease associated with abdominal pain, gastroenteritis, and diarrhea. These symptoms are induced by bacterial adherence and invasion of host epithelial cells. C. jejuni infection can occur with a low infective dose, suggesting that C. jejuni may have evolved strategies to cope with the bacterial clearance system in the gastrointestinal tract. The mucosa layer is the first line of defense against bacteria. Mucus conditions are maintained by water and anion (especially Cl(-)) movement. Cystic fibrosis transmembrane conductance regulator (CFTR) is the main Cl(-) channel transporting Cl(-) to the lumen. Mutations in CFTR result in dehydrated secreted mucus and bacterial accumulation in the lungs, and recent studies suggest that closely related pathogenic bacteria also may survive in the intestine. However, the relationship between C. jejuni infection and CFTR has been little studied. Here, we used an (125)I(-) efflux assay and measurement of short-circuit current to measure Cl(-) secretion in C. jejuni-infected T-84 human intestinal epithelial cells. The basic state of Cl(-) secretion was unchanged by C. jejuni infection, but CFTR activator was observed to induce Cl(-) secretion suppressed in C. jejuni-infected T-84 cells. The suppression of activated Cl(-) secretion was bacterial dose-dependent and duration-dependent. A similar result was observed during infection with other C. jejuni strains. The mechanism of suppression may occur by affecting water movement or mucus condition in the intestinal tract. A failure of mucus barrier function may promote bacterial adhesion or invasion of host intestinal epithelial cells, thereby causing bacterial preservation in the host intestinal tract.

Relationship between plasma (D)-dimer level and cerebral infarction volume in patients with nonvalvular atrial fibrillation.

BACKGROUND: Plasma D-dimer level may reflect the activity of thrombus formation in the left atrium of patients with nonvalvular atrial fibrillation (NVAF). Proper anticoagulation with warfarin dramatically decreases the rate of cerebral embolism, reduces stroke severity and subsequent risk of death, as well as the level of D-dimer in NVAF patients. However, the predictive value of D-dimer level on cerebral embolism severity has not been examined. Thus, the purpose of this study was to investigate the association between plasma D-dimer level at admission and infarct size in NVAF patients. METHODS: We identified 124 patients with consecutive ischemic stroke and NVAF who were admitted within 48 h of symptom onset. We measured infarction volume from CT taken after 3 ± 1 days from the onset. Plasma D-dimer levels were measured at the time of admission. Relationships were analyzed between infarction volume and plasma D-dimer levels, cardiovascular risk factors, preadmission medications and admission conditions. We also assessed the influence of D-dimer level on functional outcome in patients with preadmission modified Rankin Scale (mRS) score of 0-1 and patients by tertile of D-dimer level (≤0.83, 0.83-2.16 and ≥2.16 µg/ml). RESULTS: Infarction volume significantly correlated with D-dimer level (r = 0.309, p < 0.001), systolic blood pressure (r = 0.201, p = 0.026), diastolic blood pressure (r = 0.283, p = 0.002), National Institutes of Health Stroke Scale (NIHSS) score on admission (r = 0.546, p < 0.001) and mRS score at discharge (r = 0.557, p < 0.001). Multivariate regression analyses showed that the D-dimer level was significantly associated with infarction volume after adjusting for age, sex, current smoker or not, prothrombin time-international normalized ratio ≥1.6, diastolic blood pressure, CHADS(2) score and NIHSS score on admission. In patients with a preadmission mRS score of 0-1 (n = 108), D-dimer level was significantly associated with NIHSS score at admission (r = 0.318, p < 0.001) and mRS score at discharge (r = 0.310, p = 0.001). Patients in the highest D-dimer tertile group showed worse outcome than those in the middle (p = 0.041) and lowest (p < 0.001) tertiles. CONCLUSIONS: Plasma D-dimer level on admission is significantly related to infarction volume and functional outcome, following cardioembolic stroke in NVAF patients.

Ethanol production from wood hydrolysate using genetically engineered Zymomonas mobilis.

An ethanologenic microorganism capable of fermenting all of the sugars released from lignocellulosic biomass through a saccharification process is essential for secondary bioethanol production. We therefore genetically engineered the ethanologenic bacterium Zymomonas mobilis such that it efficiently produced bioethanol from the hydrolysate of wood biomass containing glucose, mannose, and xylose as major sugar components. This was accomplished by introducing genes encoding mannose and xylose catabolic enzymes from Escherichia coli. Integration of E. coli manA into Z. mobilis chromosomal DNA conferred the ability to co-ferment mannose and glucose, producing 91 % of the theoretical yield of ethanol within 36 h. Then, by introducing a recombinant plasmid harboring the genes encoding E. coli xylA, xylB, tal, and tktA, we broadened the range of fermentable sugar substrates for Z. mobilis to include mannose and xylose as well as glucose. The resultant strain was able to ferment a mixture of 20 g/l glucose, 20 g/l mannose, and 20 g/l xylose as major sugar components of wood hydrolysate within 72 h, producing 89.8 % of the theoretical yield. The recombinant Z. mobilis also efficiently fermented actual acid hydrolysate prepared from cellulosic feedstock containing glucose, mannose, and xylose. Moreover, a reactor packed with the strain continuously produced ethanol from acid hydrolysate of wood biomass from coniferous trees for 10 days without accumulation of residual sugars. Ethanol productivity was at 10.27 g/l h at a dilution rate of 0.25 h(-1).

HDL promotes adiponectin gene expression via the CAMKK/CAMKIV pathway.

Adiponectin (APN) is an adipokine that protects against diabetes and atherosclerosis. High-density lipoprotein (HDL) mediates reverse cholesterol transport, which also protects against atherosclerosis. In this process, the human homolog of the B class type I scavenger receptor (SR-BI/CLA-1) facilitates the cellular uptake of cholesterol from HDL. The level of circulating APN is positively correlated with the serum level of HDL-cholesterol. In this study, we investigated whether HDL stimulates the gene expression of APN through the Ca2+/calmodulin (CaM)-dependent protein kinase IV (CaMKIV) cascade. APN expression was examined using real-time PCR and western blot analysis in 3T3-L1 cells incubated with HDL. CaMKIV activity was assessed by the detection of activation loop phosphorylation (at Thr196 residue), and the effect of the constitutively active form, CaMKIVc, on APN promoter activity was investigated. Our results showed that HDL stimulated APN gene expression via hSR-BI/CLA-1. Furthermore, we explored the signaling pathways by which HDL stimulated APN expression in 3T3-L1 cells. The stimulation of APN gene expression by HDL appears to be mediated by CaMKK, as STO-609, a specific inhibitor of CaMKK2, prevents this effect. We revealed that CaMKIVc increased APN gene transcriptional activity, and the CaMKIV-dominant negative mutant blocked the effect of HDL on APN promoter activity. Finally, knockdown of hSR-BI/CLA-1 also canceled the effect of HDL on APN gene expression. These results suggest that HDL has an important role to improve the function of adipocytes by activating hSR-BI/CLA-1, and CaMKK/CaMKIV pathway is conceivable as one of the signaling pathways of this activation mechanism.

Preadmission therapeutic anticoagulation reduces cerebral infarct volume in patients with nonvalvular atrial fibrillation.

AIM: We investigated the influence of preadmission anticoagulation on infarct volume in patients with nonvalvular atrial fibrillation (NVAF). METHODS: Data were collected on consecutive ischemic stroke patients with NVAF admitted to Osaka University Hospital between 2004 and 2011. Patients were divided into 3 groups: the no-anticoagulation group, the subtherapeutic anticoagulation group [admission prothrombin time international normalized ratio (PT-INR) <1.6], and the therapeutic anticoagulation group (PT-INR ≥1.6). In analyses of neurological outcome, we excluded patients with a modified Rankin Scale (mRS) score of >1 before onset. RESULTS: Of the 68 patients, 45 were classified into the no-anticoagulation group, 9 into the subtherapeutic group, and 14 into the therapeutic group. The median value of infarct volume was 60 (interquartile range 9-176), 142 (64-184), and 8 (3-46) ml in each group, respectively. Infarct volume in the therapeutic group was significantly smaller than in the subtherapeutic group (p = 0.010), and tended to be smaller than in the no-anticoagulation group (p = 0.086). National Institute of Health Stroke Scale score at admission, and mRS score at discharge were significantly reduced in the therapeutic group compared with those in the other groups (p = 0.028 and p = 0.017, respectively). CONCLUSION: Therapeutic anticoagulation reduces infarct volume and improves neurological outcome after ischemic stroke in patients with NVAF.

Identification of Novel GCK and HNF4α Gene Variants in Japanese Pediatric Patients with Onset of Diabetes before 17 Years of Age.

BACKGROUND: Maturity-onset diabetes of the young (MODY) is commonly misdiagnosed as type 1 or type 2 diabetes. Common reasons for misdiagnosis are related to limitations in genetic testing. A precise molecular diagnosis is essential for the optimal treatment of patients and allows for early diagnosis of their asymptomatic family members. OBJECTIVE: The aim of this study was to identify rare monogenic variants of common MODY genes in Japanese pediatric patients. METHODS: We investigated 45 Japanese pediatric patients based on the following clinical criteria: development of diabetes before 17 years of age, a family history of diabetes, testing negative for glutamate decarboxylase-65 (GAD 65) antibodies and insulinoma-2-associated autoantibodies (IA-2A), no significant obesity, and evidence of endogenous insulin production. Genetic screening for MODY1 (HNF4α), MODY2 (GCK), MODY3 (HNF1α), and MODY5 (HNF1ß) was performed by direct sequencing followed by multiplex ligation amplification assays. RESULTS: We identified 22 missense variants (3 novel variants) in 27 patients (60.0%) in the GCK, HNF4α, and HNF1α genes. We also detected a whole exon deletion in the HNF1ß gene and an exon 5-6 aberration in the GCK gene, each in one proband (4.4%). There were a total of 29 variations (64.4%), giving a relative frequency of 53.3% (24/45) for GCK, 2.2% (1/45) for HNF4α, 6.7% (3/45) for HNF1α, and 2.2% (1/45) for HNF1ß genes. CONCLUSIONS: Clinicians should consider collecting and assessing detailed clinical information, especially regarding GCK gene variants, in young antibody-negative patients with diabetes. Correct molecular diagnosis of MODY better predicts the clinical course of diabetes and facilitates individualized management.

Role of ATP-binding cassette transporter A1 in suppressing lipid accumulation by glucagon-like peptide-1 agonist in hepatocytes.

OBJECTIVE: Adenosine triphosphate (ATP)-binding cassette transporter A1 (ABCA1) influences hepatic cholesterol transportation. Accumulation of hepatic cholesterol leads to fatty liver disease, which is improved by glucagon-like peptide 1 (GLP-1) in diabetes. Therefore, we analyzed the molecular mechanism in the regulation of hepatic ABCA1 by GLP-1 analogue exendin-4. METHODS: Hepatic ABCA1 expression and transcription were checked by western blotting, real-time polymerase chain reaction (PCR), and luciferase assay in HepG2 cells. Chromatin immunoprecipitation (ChIP) and site-directed mutagenesis were employed to determine transcriptional regulation of the ABCA1 gene. Prolactin regulatory element-binding (PREB)-transgenic mice were generated to access the effect of exendin-4 on improving lipid accumulation caused by a high-fat diet (HFD). RESULTS: Exendin-4 stimulated hepatic ABCA1 expression and transcription via the Ca2+/calmodulin (CaM)-dependent protein kinase kinase/CaM-dependent protein kinase IV (CaMKK/CaMKIV) pathway, whereas GLP-1 receptor antagonist exendin9-39 cancelled this effect. Therefore, exendin-4 decreased hepatic lipid content. ChIP showed that PREB could directly bind to the ABCA1 promoter, which was enhanced by exendin-4. Moreover, PREB stimulated ABCA1 promoter activity, and mutation of PREB-binding site in ABCA1 promoter cancelled exendin-4-enhanced ABCA1 promoter activity. Silencing of PREB attenuated the effect of exendin-4 and induced hepatic cholesterol accumulation. Blockade of CaMKK by STO-609 or siRNA cancelled the upregulation of ABCA1 and PREB induced by exendin-4. In vivo, exendin-4 or overexpression of PREB increased hepatic ABCA1 expression and decreased hepatic lipid accumulation and high plasma cholesterol caused by a HFD. CONCLUSIONS: Our data shows that exendin-4 stimulates hepatic ABCA1 expression and decreases lipid accumulation by the CaMKK/CaMKIV/PREB pathway, suggesting that ABCA1 and PREB might be the therapeutic targets in fatty liver disease.

Simple standing test predicts and water ingestion prevents vasovagal reaction in the high-risk blood donors.

BACKGROUND: One of the serious complications of blood donation is vasovagal reaction (VVR) with syncope. This study was performed to determine if the measurement of hemodynamic responses to standing before blood collection (BC) was useful to identify the high-risk donors for VVR and also examined the effect of 300 mL of water ingestion in the prevention of VVR. STUDY DESIGN AND METHODS: Blood pressure and heart rate (HR) during 5 minutes of standing were examined before and after BC in 93 donors. Because HR increase of 6 of 7 donors who developed syncopal VVR during standing after BC was 15 beats per minute (bpm) or greater, those with HR increase of 15 bpm or greater were determined as high-risk donors (n = 31). In another group (n = 117), 45 donors were identified as high risk based on the HR response before BC (15 bpm). The effect of 300 mL of water ingestion 15 minutes before BC on hemodynamic responses to standing and the rate of VVR after BC were analyzed. RESULTS: Water ingestion given to the high-risk donors of the second group reduced HR increase with standing before BC (-6.6 ± 13.6 bpm, p < 0.02 vs. HR increase before water ingestion) and significantly suppressed VVR rate (2 of 45 donors with high risk, 4.4%,p < 0.04 vs. the first group; 6 of 31 high-risk donors, 19.4%). CONCLUSION: HR response to standing before BC may detect the high-risk donors for VVR. For the high-risk donors, 300 mL of water ingestion may be a simple and effective way of prevention against syncopal VVR.

Association between cerebral small vessel diseases and mild parkinsonian signs in the elderly with vascular risk factors.

INTRODUCTION: The aim of this study was to examine the association between mild parkinsonian signs (MPS), cerebral small-vessel disease (SVD), and total SVD burden in patients with vascular risk factors. METHODS: We performed a cross-sectional study among 268 patients with vascular risk factors but without parkinsonism or dementia (71.0 ± 7.8 years, 63% male). MPS was evaluated via Unified Parkinson's Disease Rating Scale Part III. Brain MRI was used to determine SVD (cerebral microbleeds [CMBs], lacunar infarctions [LIs], and white matter hyperintensities [WMH]). The presence of each SVD feature was indicated by the total SVD score. Logistic regression analyses were performed adjusting for age, sex, history of stroke, hypertension, diabetes mellitus, and dyslipidemia. RESULTS: In a multivariate analysis, we found that the presence of CMBs, deep CMBs, mixed (in the basal ganglia and thalamus) LIs, periventricular hyperintensities (PVH), and deep WMH (DWMH), and total SVD score were significantly associated with MPS, whereas strictly lobar CMBs and other LIs (in strictly basal ganglia or strictly thalamus) were not. We also found a significant association between mixed LIs, PVH, DWMH and total SVD score and gait/balance function, between PVH and rigidity, and between mixed LIs and bradykinesia. Among elderly participants (≥73years), the association of total SVD score, deep CMBs, mixed LIs, and PVH, with MPS remained significant. CONCLUSION: Our results provide additional evidence that SVD including CMBs, and especially total SVD burden, might be a surrogate marker for MPS and support the contribution of hypertensive microangiopathy as the underlying etiology.

Interaction between methyl CpG-binding protein and ran GTPase during cell division in tobacco cultured cells.

BACKGROUND AND AIMS: Methyl CpG-binding proteins are considered to play critical roles in epigenetic control of gene expression by recognizing and interacting with 5-methylcytosine (m(5)C) in eukaryotes. However, among 13 corresponding genes in Arabidopsis thaliana, designated as featuring a methyl-binding domain (MBD), only four have so far been shown actually to bind to m(5)C. One example, AtMBD5, was selected here to screen for interacting proteins. METHODS: Yeast two-hybrid assays were used for screening, and physical interaction was confirmed by pull-down and bimolecular fluorescence complementation (BiFC) assays. Cellular localization was analysed by fluorescence-tagged fusion proteins using tobacco (Nicotiana tabacum) cultured bright yellow 2 cells. KEY RESULTS: A gene finally identified was found to encode AtRAN3, a protein that belongs to the Ran GTPase family, which plays a critical role in nucleocytoplasmic transport and spindle bipolarization during cell division. AtMBD5 and AtRAN3 were clearly shown to interact in the nucleus by BiFC. On co-expression of AtMBD5-cyan fluorescence protein and yellow fluorescence protein-AtRAN3 in tobacco cells, both localized to the nucleus in the resting stage, migrating to the cytoplasm, primarily around chromatin, during mitosis, particularly at metaphase. CONCLUSIONS: These results suggest that AtMBD5 becomes localized to the vicinity of chromosomes with the aid of AtRAN3 during cell division, and may play an important role not only in maintenance of chromatin structures by binding to m(5)C, but also in progress through mitosis by detaching from m(5)C. The present findings also shed light on the physiological function of Ran GTPases, direct target proteins of which have not thus far been well defined, suggesting their key role in chromatin movements in plant cells.