Exploration of urine metabolic biomarkers for new-onset, untreated pediatric epilepsy: A gas and liquid chromatography mass spectrometry-based metabolomics study

OBJECTIVE

The discovery of objective indicators for recent epileptic seizures will help confirm the diagnosis of epilepsy and evaluate therapeutic effects. Past studies had shortcomings such as the inclusion of patients under treatment and those with various etiologies that could confound the analysis results significantly. We aimed to minimize such confounding effects and to explore the small molecule biomarkers associated with the recent occurrence of epileptic seizures using urine metabolomics.

METHODS

This is a multicenter prospective study. Subjects included pediatric patients aged 2 to 12 years old with new-onset, untreated epilepsy, who had had the last seizure within 1 month before urine collection. Controls included healthy children aged 2 to 12 years old. Those with underlying or chronic diseases, acute illnesses, or recent administration of medications or supplements were excluded. Targeted metabolome analysis of spot urine samples was conducted using gas chromatography (GC)- and liquid chromatography (LC)-tandem mass spectrometry (MS/MS).

RESULTS

We enrolled 17 patients and 21 controls. Among 172 metabolites measured by GC/MS/MS and 41 metabolites measured by LC/MS/MS, only taurine was consistently reduced in the epilepsy group. This finding was subsequently confirmed by the absolute quantification of amino acids. No other metabolites were consistently altered between the two groups.

CONCLUSIONS

Urine metabolome analysis, which covers a larger number of metabolites than conventional biochemistry analyses, found no consistently altered small molecule metabolites except for reduced taurine in epilepsy patients compared to healthy controls. Further studies with larger samples, subjects with different ages, expanded target metabolites, and the investigation of plasma samples are required.

Dietary habits and plasma lipid concentrations in a general Japanese population

INTRODUCTION

Accumulating data on the associations between food consumption and lipid composition in the body is essential for understanding the effects of dietary habits on health.

OBJECTIVES

As part of omics research in the Tohoku Medical Megabank Community-Based Cohort Study, this study sought to reveal the dietary impact on plasma lipid concentration in a Japanese population.

METHODS

We conducted a correlation analysis of food consumption and plasma lipid concentrations measured using mass spectrometry, for 4032 participants in Miyagi Prefecture, Japan.

RESULTS

Our analysis revealed 83 marked correlations between six food categories and the concentrations of plasma lipids in nine subclasses. Previously reported associations, including those between seafood consumption and omega-3 fatty acids, were validated, while those between dairy product consumption and odd-carbon-number fatty acids (odd-FAs) were validated for the first time in an Asian population. Further analysis suggested that dairy product consumption is associated with odd-FAs via sphingomyelin (SM), which suggests that SM is a carrier of odd-FAs. These results are important for understanding odd-FA metabolism with regards to dairy product consumption.

CONCLUSION

This study provides insight into the dietary impact on plasma lipid concentration in a Japanese population.

Reduced glutathione level in the aqueous humor of patients with primary open-angle glaucoma and normal-tension glaucoma

Glaucoma is a leading cause of blindness worldwide in older people. Profiling the aqueous humor, including the metabolites it contains, is useful to understand physiological and pathological conditions in the eye. In the current study, we used mass spectrometry (MS) to characterize the aqueous humor metabolomic profile and biological features of patients with glaucoma. Aqueous humor samples were collected during trabeculectomy surgery or cataract surgery and analyzed with global metabolomics. We included 40 patients with glaucoma (32 with POAG, 8 with NTG) and 37 control subjects in a discovery study. VIP analysis revealed five metabolites that were elevated and three metabolites that were reduced in the glaucoma patients. The identified metabolomic profile had an area under the receiver operating characteristic curve of 0.953. Among eight selected metabolites, the glutathione level was significantly decreased in association with visual field defects. Moreover, in a validation study to confirm the reproducibility of our findings, the glutathione level was reduced in NTG and POAG patients compared with a cataract control group. Our findings demonstrate that aqueous humor profiling can help to diagnose glaucoma and that various aqueous humor metabolites are correlated with clinical parameters in glaucoma patients. In addition, glutathione is clearly reduced in the aqueous humor of glaucoma patients with both IOP-dependent and IOP-independent disease subtypes. These findings indicate that antioxidant agents in the aqueous humor reflect glaucomatous optic nerve damage and that excessive oxidative stress may be involved in the pathogenesis of glaucoma.

Global Proteomics for Identifying the Alteration Pathway of Niemann-Pick Disease Type C Using Hepatic Cell Models

Niemann-Pick disease type C (NPC) is an autosomal recessive disorder with progressive neurodegeneration. Although the causative genes were previously identified, NPC has unclear pathophysiological aspects, and patients with NPC present various symptoms and onset ages. However, various novel biomarkers and metabolic alterations have been investigated; at present, few comprehensive proteomic alterations have been reported in relation to NPC. In this study, we aimed to elucidate proteomic alterations in NPC and perform a global proteomics analysis for NPC model cells. First, we developed two NPC cell models by knocking out NPC1 using CRISPR/Cas9 (KO1 and KO2). Second, we performed a label-free (LF) global proteomics analysis. Using the LF approach, more than 300 proteins, defined as differentially expressed proteins (DEPs), changed in the KO1 and/or KO2 cells, while the two models shared 35 DEPs. As a bioinformatics analysis, the construction of a protein-protein interaction (PPI) network and an enrichment analysis showed that common characteristic pathways such as ferroptosis and mitophagy were identified in the two model cells. There are few reports of the involvement of NPC in ferroptosis, and this study presents ferroptosis as an altered pathway in NPC. On the other hand, many other pathways and DEPs were previously suggested to be associated with NPC, supporting the link between the proteome analyzed here and NPC. Therapeutic research based on these results is expected in the future.

Identification of predictive biomarkers for endometrial cancer diagnosis and treatment response monitoring using plasma metabolome profiling

BACKGROUND

Endometrial cancer (EMC) is the most common female genital tract malignancy with an increasing prevalence in many countries including Japan, a fact that renders early detection and treatment necessary to protect health and fertility. Although early detection and treatment are necessary to further improve the prognosis of women with endometrial cancer, biomarkers that accurately reflect the pathophysiology of EMC patients are still unclear. Therefore, it is clinically critical to identify biomarkers to assess diagnosis and treatment efficacy to facilitate appropriate treatment and development of new therapies for EMC.

METHODS

In this study, wide-targeted plasma metabolome analysis was performed to identify biomarkers for EMC diagnosis and the prediction of treatment responses. The absolute quantification of 628 metabolites in plasma samples from 142 patients with EMC was performed using ultra-high-performance liquid chromatography with tandem mass spectrometry.

RESULTS

The concentrations of 111 metabolites increased significantly, while the concentrations of 148 metabolites decreased significantly in patients with EMC compared to healthy controls. Specifically, LysoPC and TGs, including unsaturated fatty acids, were reduced in patients with stage IA EMC compared to healthy controls, indicating that these metabolic profiles could be used as early diagnostic markers of EMC. In contrast, blood levels of amino acids such as histidine and tryptophan decreased as the risk of recurrence increased and the stages of EMC advanced. Furthermore, a marked increase in total TG and a decrease in specific TGs and free fatty acids including polyunsaturated fatty acids levels were observed in patients with EMC. These results suggest that the polyunsaturated fatty acids in patients with EMC are crucial for disease progression.

CONCLUSIONS

Our data identified specific metabolite profiles that reflect the pathogenesis of EMC and showed that these metabolites correlate with the risk of recurrence and disease stage. Analysis of changes in plasma metabolite profiles could be applied for the early diagnosis and monitoring of the course of treatment of EMC patients.

Identification of predictive biomarkers for diagnosis and radiation sensitivity of uterine cervical cancer using wide-targeted metabolomics

AIM

Uterine cervical cancer (UCC) is the fourth most common cancer in women, responsible for more than 300 000 deaths worldwide. Its early detection, by cervical cytology, and prevention, by vaccinating against human papilloma virus, greatly contribute to reducing cervical cancer mortality in women. However, penetration of the effective prevention of UCC in Japan remains low. Plasma metabolome analysis is widely used for biomarker discovery and the identification of cancer-specific metabolic pathways. Here, we aimed to identify predictive biomarkers for the diagnosis and radiation sensitivity of UCC using wide-targeted plasma metabolomics.

METHODS

We analyzed 628 metabolites in plasma samples obtained from 45 patients with UCC using ultra-high-performance liquid chromatography with tandem mass spectrometry.

RESULTS

The levels of 47 metabolites were significantly increased and those of 75 metabolites were significantly decreased in patients with UCC relative to healthy controls. Increased levels of arginine and ceramides, and decreased levels of tryptophan, ornithine, glycosylceramides, lysophosphatidylcholine, and phosphatidylcholine were characteristic of patients with UCC. Comparison of metabolite profiles in groups susceptible and non-susceptible to radiation therapy, a treatment for UCC, revealed marked variations in polyunsaturated fatty acid, nucleic acid, and arginine metabolism in the group not susceptible to treatment.

CONCLUSIONS

Our findings suggest that the metabolite profile of patients with UCC may be an important indicator for distinguishing these patients from healthy cohorts, and may also be useful for predicting sensitivity to radiotherapy.

Comprehensive study of metabolic changes induced by a ketogenic diet therapy using GC/MS- and LC/MS-based metabolomics

OBJECTIVE

The ketogenic diet (KD), a high-fat and low-carbohydrate diet, is effective for a subset of patients with drug-resistant epilepsy, although the mechanisms of the KD have not been fully elucidated. The aims of this observational study were to investigate comprehensive short-term metabolic changes induced by the KD and to explore candidate metabolites or pathways for potential new therapeutic targets.

METHODS

Subjects included patients with intractable epilepsy who had undergone the KD therapy (the medium-chain triglyceride [MCT] KD or the modified Atkins diet using MCT oil). Plasma and urine samples were obtained before and at 2-4 weeks after initiation of the KD. Targeted metabolome analyses of these samples were performed using gas chromatography-tandem mass spectrometry (GC/MS/MS) and liquid chromatography-tandem mass spectrometry (LC/MS/MS).

RESULTS

Samples from 10 and 11 patients were analysed using GC/MS/MS and LC/MS/MS, respectively. The KD increased ketone bodies, various fatty acids, lipids, and their conjugates. In addition, levels of metabolites located upstream of acetyl-CoA and propionyl-CoA, including catabolites of branched-chain amino acids and structural analogues of γ-aminobutyric acid and lactic acid, were elevated.

CONCLUSIONS

The metabolites that were significantly changed after the initiation of the KD and related metabolites may be candidates for further studies for neuronal actions to develop new anti-seizure medications.

Plasma metabolic disturbances during pregnancy and postpartum in women with depression

Examining plasma metabolic profiling during pregnancy and postpartum could help clinicians understand the risk factors for postpartum depression (PPD) development. This analysis targeted paired plasma metabolites in mid-late gestational and 1 month postpartum periods in women with (n = 209) or without (n = 222) PPD. Gas chromatogram-mass spectrometry was used to analyze plasma metabolites at these two time points. Among the 170 objected plasma metabolites, principal component analysis distinguished pregnancy and postpartum metabolites but failed to discriminate women with and without PPD. Compared to women without PPD, those with PPD exhibited 37 metabolites with disparate changes during pregnancy and the 1-month postpartum period and an enriched citrate cycle. Machine learning and multivariate statistical analysis identified two or three compounds that could be potential biomarkers for PPD prediction during pregnancy. Our findings suggest metabolic disturbances in women with depression and may help to elucidate metabolic processes associated with PPD development.

Nrf2 deficiency deteriorates diabetic kidney disease in Akita model mice

Oxidative stress is an essential component in the progression of diabetic kidney disease (DKD), and the transcription factor NF-E2-related factor-2 (Nrf2) plays critical roles in protecting the body against oxidative stress. To clarify the roles of Nrf2 in protecting against DKD, in this study we prepared compound mutant mice with diabetes and loss of antioxidative defense. Specifically, we prepared compound Ins2^Akita/+ (Akita) and Nrf2 knockout (Akita::Nrf2^-/-) or Akita and Nrf2 induction (Akita::Keap1^FA/FA) mutant mice. Eighteen-week-old Akita::Nrf2^-/- mice showed more severe diabetic symptoms than Akita mice. In the Akita::Nrf2^-/- mouse kidneys, the glomeruli showed distended capillary loops, suggesting enhanced mesangiolysis. Distal tubules showed dilation and an increase in 8-hydroxydeoxyguanosine-positive staining. In the Akita::Nrf2^-/- mouse kidneys, the expression of glutathione (GSH) synthesis-related genes was decreased, and the actual GSH level was decreased in matrix-assisted laser desorption/ionization mass spectrometry imaging analysis. Akita::Nrf2^-/- mice exhibited severe inflammation and enhancement of infiltrated macrophages in the kidney. To further examine the progression of DKD, we compared forty-week-old Akita mouse kidney compounds with Nrf2-knockout or Nrf2 mildly induced (Akita::Keap1^FA/FA) mice. Nrf2-knockout Akita (Akita::Nrf2^-/-) mice displayed severe medullary cast formation, but the formation was ameliorated in Akita::Keap1^FA/FA mice. Moreover, in Akita::Keap1^FA/FA mice, tubule injury and inflammation-related gene expression were significantly suppressed, which was evident in Akita::Nrf2^-/- mouse kidneys. These results demonstrate that Nrf2 contributes to the protection of the kidneys against DKD by suppressing oxidative stress and inflammation.

Nrf2 plays a critical role in the metabolic response during and after spaceflight

Space travel induces stresses that contribute to health problems, as well as inducing the expression of Nrf2 (NF-E2-related factor-2) target genes that mediate adaptive responses to oxidative and other stress responses. The volume of epididymal white adipose tissue (eWAT) in mice increases during spaceflight, a change that is attenuated by Nrf2 knockout. We conducted metabolome analyses of plasma from wild-type and Nrf2 knockout mice collected at pre-flight, in-flight and post-flight time points, as well as tissues collected post-flight to clarify the metabolic responses during and after spaceflight and the contribution of Nrf2 to these responses. Plasma glycerophospholipid and sphingolipid levels were elevated during spaceflight, whereas triacylglycerol levels were lower after spaceflight. In wild-type mouse eWAT, triacylglycerol levels were increased, but phosphatidylcholine levels were decreased, and these changes were attenuated in Nrf2 knockout mice. Transcriptome analyses revealed marked changes in the expression of lipid-related genes in the liver and eWAT after spaceflight and the effects of Nrf2 knockout on these changes. Based on these results, we concluded that space stress provokes significant responses in lipid metabolism during and after spaceflight; Nrf2 plays critical roles in these responses.

Comparison of Kit-Based Metabolomics with Other Methodologies in a Large Cohort, towards Establishing Reference Values

Metabolic profiling is an omics approach that can be used to observe phenotypic changes, making it particularly attractive for biomarker discovery. Although several candidate metabolites biomarkers for disease expression have been identified in recent clinical studies, the reference values of healthy subjects have not been established. In particular, the accuracy of concentrations measured by mass spectrometry (MS) is unclear. Therefore, comprehensive metabolic profiling in large-scale cohorts by MS to create a database with reference ranges is essential for evaluating the quality of the discovered biomarkers. In this study, we tested 8700 plasma samples by commercial kit-based metabolomics and separated them into two groups of 6159 and 2541 analyses based on the different ultra-high-performance tandem mass spectrometry (UHPLC-MS/MS) systems. We evaluated the quality of the quantified values of the detected metabolites from the reference materials in the group of 2541 compared with the quantified values from other platforms, such as nuclear magnetic resonance (NMR), supercritical fluid chromatography tandem mass spectrometry (SFC-MS/MS) and UHPLC-Fourier transform mass spectrometry (FTMS). The values of the amino acids were highly correlated with the NMR results, and lipid species such as phosphatidylcholines and ceramides showed good correlation, while the values of triglycerides and cholesterol esters correlated less to the lipidomics analyses performed using SFC-MS/MS and UHPLC-FTMS. The evaluation of the quantified values by MS-based techniques is essential for metabolic profiling in a large-scale cohort.

Machine learning approaches to predict gestational age in normal and complicated pregnancies via urinary metabolomics analysis

The elucidation of dynamic metabolomic changes during gestation is particularly important for the development of methods to evaluate pregnancy status or achieve earlier detection of pregnancy-related complications. Some studies have constructed models to evaluate pregnancy status and predict gestational age using omics data from blood biospecimens; however, less invasive methods are desired. Here we propose a model to predict gestational age, using urinary metabolite information. In our prospective cohort study, we collected 2741 urine samples from 187 healthy pregnant women, 23 patients with hypertensive disorders of pregnancy, and 14 patients with spontaneous preterm birth. Using gas chromatography-tandem mass spectrometry, we identified 184 urinary metabolites that showed dynamic systematic changes in healthy pregnant women according to gestational age. A model to predict gestational age during normal pregnancy progression was constructed; the correlation coefficient between actual and predicted weeks of gestation was 0.86. The predicted gestational ages of cases with hypertensive disorders of pregnancy exhibited significant progression, compared with actual gestational ages. This is the first study to predict gestational age in normal and complicated pregnancies by using urinary metabolite information. Minimally invasive urinary metabolomics might facilitate changes in the prediction of gestational age in various clinical settings.

Identification of biomarkers to diagnose diseases and find adverse drug reactions by metabolomics

Metabolomics has been widely used for investigating the biological functions of disease expression and has the potential to discover biomarkers in circulating biofluids or tissue extracts that reflect in phenotypic changes. Metabolic profiling has advantages because of the use of unbiased techniques, including multivariate analysis, and has been applied in pharmacological studies to predict therapeutic and adverse reactions of drugs, which is called pharmacometabolomics (PMx). Nuclear magnetic resonance (NMR)- and mass spectrometry (MS)-based metabolomics has contributed to the discovery of recent disease biomarkers; however, the optimal strategy for the study purpose must be selected from many established protocols, methodologies and analytical platforms. Additionally, information on molecular localization in tissue is essential for further functional analyses related to therapeutic and adverse effects of drugs in the process of drug development. MS imaging (MSI) is a promising technology that can visualize molecules on tissue surfaces without labeling and thus provide localized information. This review summarizes recent uses of MS-based global and wide-targeted metabolomics technologies and the advantages of the MSI approach for PMx and highlights the PMx technique for the biomarker discovery of adverse drug effects.

Stiripentol for the treatment of super-refractory status epilepticus with cross-sensitivity

BACKGROUND

Cross-sensitivity of rash has been reported between various antiepileptic drugs (AEDs). However, few studies have determined the frequency and management of cross-sensitivity in patients with super-refractory status epilepticus (SRSE).

AIMS OF THE STUDY

To examine the optimal AED for treating SRSE with cross-sensitivity.

METHODS

We performed a retrospective review of adult patients with SRSE treated at Nagoya City University Hospital, in which we investigated the frequency of cross-sensitivity among patients with SRSE and their clinical and medical profiles.

RESULTS

We identified 10 adult patients with SRSE, 5 of whom had cross-sensitivity. Stiripentol (STP) was administered when previously used AEDs had demonstrated cross-sensitivity and failed to control seizures. After initiation of STP, the dose of general anaesthetics was reduced, and status epilepticus (SE) eventually ceased with co-administered AEDs without additional adverse effects. The mean time to SE cessation after initiation of STP was 30.8 days (range, 18-46 days), mean duration of general anaesthesia was 101.2 days (range, 74-128 days), and mean number of AEDs was 9.0 (range, 6-11).

CONCLUSIONS

This study suggests that cross-sensitivity between AEDs is common in adults with SRSE and that STP may be useful for treating SRSE with cross-sensitivity.

Polymyxins as novel and safe mucosal adjuvants to induce humoral immune responses in mice

There is currently an urgent need to develop safe and effective adjuvants for enhancing vaccine-induced antigen-specific immune responses. We demonstrate here that intranasal immunization with clinically used polypeptide antibiotics, polymyxin B (PMB) and colistin (CL), along with ovalbumin (OVA), increases OVA-specific humoral immune responses in a dose-dependently manner at both mucosal and systemic compartments. Enhanced immunity by boosting was found to persist during 8 months of observation. Moreover, mice intranasally immunized with OVA plus various doses of PMB or CL showed neither inflammatory responses in the nasal cavity and olfactory bulbs nor renal damages, compared to those given OVA alone. These data suggest that polymyxins may serve as novel and safe mucosal adjuvants to induce humoral immune responses. The polymyxin adjuvanticity was found to be independent of endotoxins liberated by its bactericidal activity, as indicated by similar enhancing effects of PMB in lipopolysaccharide (LPS)-hyporesponsive and LPS-susceptible mice. However, despite the presence of preexisting anti-PMB antibodies, we observed no reduction in the adjuvant function of polymyxins when they were given intranasally. Furthermore, the titers of OVA-specific Abs in mice intranasally immunized with OVA plus PMB or CL were significantly higher than those in mice administered with polymyxin analogues, such as polymyxin B nonapeptide and colistin methanesulfonate. The levels of released β-hexosaminidase and histamine in mast cell culture supernatants stimulated by PMB or CL were also significantly higher than those stimulated by their analogues. These results suggest that both the hydrophobic carbon chain and hydrophilic cationic cyclic peptide contribute to the mucosal adjuvanticity of PMB and CL.

Mannitol facilitates neurotrophic factor up-regulation and behavioural recovery in neonatal hypoxic-ischaemic rats with human umbilical cord blood grafts

We recently demonstrated that blood–brain barrier permeabilization using mannitol enhances the therapeutic efficacy of systemically administered human umbilical cord blood (HUCB) by facilitating the entry of neurotrophic factors from the periphery into the adult stroke brain. Here, we examined whether the same blood–brain barrier manipulation approach increases the therapeutic effects of intravenously delivered HUCB in a neonatal hypoxic-ischaemic (HI) injury model. Seven-day-old Sprague–Dawley rats were subjected to unilateral HI injury and then at day 7 after the insult, animals intravenously received vehicle alone, mannitol alone, HUCB cells (15k mononuclear fraction) alone or a combination of mannitol and HUCB cells. Behavioural tests at post-transplantation days 7 and 14 showed that HI animals that received HUCB cells alone or when combined with mannitol were significantly less impaired in motor asymmetry and motor coordination compared with those that received vehicle alone or mannitol alone. Brain tissues from a separate animal cohort from the four treatment conditions were processed for enzyme-linked immunosorbent assay at day 3 post-transplantation, and revealed elevated levels of GDNF, NGF and BDNF in those that received HUCB cells alone or when combined with mannitol compared with those that received vehicle or mannitol alone, with the combined HUCB cells and mannitol exhibiting the most robust neurotropic factor up-regulation. Histological assays revealed only sporadic detection of HUCB cells, suggesting that the trophic factor–mediated mechanism, rather than cell replacement per se, principally contributed to the behavioural improvement. These findings extend the utility of blood–brain barrier permeabilization in facilitating cell therapy for treating neonatal HI injury.

Hexagonal close-packed array formed by selective adsorption onto hexagonal patterns

A patterned two-dimensional hexagonally ordered array of ferritin molecules, the outer surfaces of which had been genetically modified by titanium (Ti) specific binding peptides (minT1-LF), was realized in a self-assembling manner on a hexagonal Ti thin film island made on a silicon substrate. The optimum degree of order was realized at the pH with the maximum selectivity of minT1-LF adsorption on the Ti surface with respect to the silicon dioxide (SiO2) surface. Quartz crystal microbalance (QCM) measurement revealed that minT1-LF adsorbed onto the Ti surface strongly and irreversibly, but adsorbed onto the silicon dioxide surface weakly and reversibly. It was suggested that the concentration of minT1-LF on the Ti pattern promotes hexagonal close-packed ordering and axis aligning.

Lack of exercise, via hindlimb suspension, impedes endogenous neurogenesis

Bedridden patients who receive good physical rehabilitation are able to exhibit clinical improvement. Accumulating evidence demonstrates that exercise increases endogenous neurogenesis and may even protect against central nervous system (CNS) disorders. Here, we explored the effects of lack of exercise on neurogenesis in rats by employing a routine hindlimb suspension (HS) model over a 2-week period, which consists of elevating their tails, thereby raising their hindlimbs above the ground and unloading the weights in these extremities. In addition, the effects of exercise and recovery time with normal caging after HS were also explored. BrdU (50 mg/kg, i.p.) was injected every 8 h over the last 4 days of each paradigm to label proliferative cells. Immunohistochemical results revealed that HS significantly reduced the number of BrdU/Doublecortin double-positive cells in the subventricular zone and dentate gyrus. Exercise and recovery time significantly improved atrophy of the soleus muscle, but did not attenuate the HS-induced decrement in BrdU/Dcx-positive cells. A separate cohort of animals was exposed to the same HS paradigm and enzyme-linked immunosorbent assay (ELISA) of neurotrophic factors was performed on brain tissue samples harvested at the end of the HS period, as well as plasma samples from all animals. ELISA results revealed that HS reduced the levels of brain-derived neurotrophic factor in the hippocampus and vascular endothelial growth factor plasma levels. This study revealed that lack of exercise reduced neurogenesis with downregulation of neurotrophic factors. The use of the HS model in conjunction with CNS disease models should further elucidate the role of exercise in neurogenesis and neurotrophic factors in neurologic disorders.

Overexpression of D2/D3 receptors increases efficacy of ropinirole in chronically 6-OHDA-lesioned Parkinsonian rats

Ropinirole, which is a non-ergot dopamine agonist derivative, exerts therapeutic benefits in Parkinson's disease (PD). Based on recent studies implicating dopamine receptors 2 and 3 (D2R and D3R) as possible targets of ropinirole, we over-expressed these dopamine receptor genes in the dopamine-denervated striatum of rodents to reveal whether their over-expression modulated ropinirole activity. Adult Sprague-Dawley rats initially received unilateral 6-hydroxydopamine lesion of the medial forebrain bundle. At 1 month after surgery, successfully lesioned animals (3 or less forelimb akinesia score, and 8 or more apomorphine-induced rotations/min over 1 h) were randomly assigned to intrastriatal injection (ipsilateral to the lesion) of blank lentiviral vector, D2R, D3R or both genes. At about 5 months post-lesion, ropinirole (0.2 mg/kg, i.p.) was administered daily for 9 consecutive days. The subtherapeutic dose of ropinirole improved the use of previously akinetic forelimb and produced robust circling behavior in lesioned animals with striatal over-expression of both D2R and D3R compared to lesioned animals that received blank vector. In contrast, the subtherapeutic dose of ropinirole generated only modest motor effects in lesioned animals with sole over-expression of D2R or D3R. Western immunoblot and autoradiographic assays showed enhanced D2R and D3R protein levels coupled with normalized D2R and D3R binding in the ventral striatum of lesioned animals with lentiviral over-expression of both D2R and D3R relative to vehicle-treated lesioned animals. Immunohistochemical analyses showed that D2R and D3R GFP fluorescent cells colocalized with enkephalin and substance P immunoreactive medium spiny neurons. These data support the use of the subtherapeutic dose of ropinirole in a chronic model of PD.

Brain Malformations Caused by Retroviral Vector-Mediated Gene Transfer of Hippocampal Cholinergic Neurostimulating Peptide Precursor Protein into the CNS via Embryonic Mice Ventricles

Hippocampal cholinergic neurostimulating peptide precursor protein (HCNP-pp) is a unique multifunctional protein, being not only the precursor of HCNP, which promotes the phenotype development of septo-hippocampal cholinergic neurons, but also the binding protein of phosphatidylethanolamine, ATP, Raf-1 kinase (known as "Raf-1 kinase inhibitory factor" in peripheral organs), and serine protease. We obtained a high-titer retroviral vector harboring HCNP-pp cDNA by the use of a modified packaging cell line and centrifugation, and by injecting it into embryonic mouse ventricles, we investigated the function of its gene product within the central nervous system (CNS). We found that efficient transduction into hippocampal pyramidal neurons can be achieved by injecting the vector into embryonic brain ventricles on embryonic day 14 (E14). Three days after receiving the intraventricular injection of the high-titer HCNP-pp retrovirus vector on E14, the tissues around the ventricles showed an overexpression of HCNP-pp. This was accompanied by a reduced amount of activated MEK and Erk (as analyzed by histochemical and Western blot methods), suggesting that HCNP-pp also regulates the MAP-kinase cascade within the CNS. Surprisingly, mouse brains that received the HCNP-pp retroviral vector showed massive malformation of the hippocampus and cerebellum when examined 30 days after birth. This shows that strictly regulated HCNP-pp gene expression is necessary for the normal development of the mouse brain, and that the moderate overexpression achieved by retroviral vector-mediated gene transfer is sufficient to cause severe abnormality of entire brain structures.

Anti-atherogenic antioxidants regulate the expression and function of proteasome alpha-type subunits in human endothelial cells

It has been proposed that phenolic antioxidants such as probucol exert their anti-atherogenic effects through scavenging lipid-derived radicals. In this study the potential for genomics to reveal unanticipated pharmacological properties of phenolic antioxidants is explored. It was found that two anti-atherogenic compounds, BO-653 and probucol, inhibited the expression of three alpha-type proteasome subunits, PMSA2, PMSA3, and PMSA4 in human umbilical vein endothelial cells. Here we report that both BO-653 and probucol caused not only inhibition of the mRNA levels of these three subunits but also inhibition of both the gene expression and protein synthesis of the alpha-type subunit, PMSA1. Other subunit components of the proteasome such as the beta-type subunits (PMSB1, PMSB7), the ATPase subunit of 19 S (PMSC6), the non-ATPase subunit of 19 S (PMSD1), and PA28 (PMSE2) were not significantly affected by treatment with these compounds. The specific inhibition of alpha-type subunit expression in response to these antioxidants resulted in functional alterations of the proteasome with suppression of degradation of multiubiquitinated proteins and IkappaBalpha. These results suggest that certain compounds previously classified solely as antioxidants are able to exert potentially important modulatory effects on proteasome function.

Muscarinic cholinergic and glutamatergic reciprocal regulation of expression of hippocampal cholinergic neurostimulating peptide precursor protein gene in rat hippocampus

Hippocampal cholinergic neurostimulating peptide, an undecapeptide originally isolated from the hippocampus of young rats, enhances acetylcholine synthesis in rat medial septal nucleus in vitro. Hippocampal cholinergic neurostimulating peptide is derived from the N-terminal region of its 21-kmol.wt precursor protein. The highest expression of the hippocampal cholinergic neurostimulating peptide precursor protein messenger RNA is in hippocampal pyramidal neurons. In an in vitro rat hippocampal slice, preparation in which electrical stimulation could be delivered to the Schaffer collateral-CA1 pyramidal cell synapse, semi-quantitative non-radioisotopic in situ hybridization, demonstrated that expression of the hippocampal cholinergic neurostimulating peptide precursor protein messenger RNA is regulated by neuronal activity. Selective inhibition with pharmacological agents revealed that the constitutive hippocampal cholinergic neurostimulating peptide precursor protein messenger RNA level can be up-regulated by D-(-)-2-amino-5-phosphono-valeric acid, and that activity-dependent transcription can be inhibited by tetrodotoxin, nifedipine, 6-cyano-7-nitroquinoxaline-2,3-dione, and scopolamine, but not by mecamylamine. These results indicate that septal cholinergic neurons and hippocampal glutamatergic neurons exert a reciprocal influence over the expression of hippocampal cholinergic neurostimulating peptide precursor protein messenger RNA in the hippocampus, and that the activity-dependent and constitutive expressions of hippocampal cholinergic neurostimulating peptide precursor protein messenger RNA may be regulated by different routes, involving calcium influx via L-type Ca(2+) channels and N-methyl-D-aspartate receptors.

Age-dependent changes in HCNP-related antigen expression in the human hippocampus

Hippocampal cholinergic neurostimulating peptide (HCNP), originally purified from the young rat hippocampus, enhances the cholinergic phenotype development of the medial septal nucleus in vitro. In this study, we examined the HCNP-antigen distribution and the age-related changes in the number of positive cells in the hippocampus (obtained at autopsy from 74 subjects with no known neurological disorders). Immunohistochemical assay revealed that the immunopositive cells were GABAergic neurons and oligodendrocytes. They were first identified in the fetus at around 25 to 30 weeks and their number increased rapidly with advancing postconceptional age to reach maximal at the perinatal stage and in early postnatal life; it then decreased to the adult level by 10 years old. These results suggest that HCNP-related antigen may play important roles in the development and/or differentiation of the human hippocampus.

[A case of sarcoid meningoencephalitis with an isolated supratentorial lesion]

A rare case of sarcoid meningoencephalitis with no systemic lesion is reported here. A 58-year old man was admitted experiencing dull headache and speech disturbance. He had never received a diagnosis of systemic sarcoidosis. On admission, neurological examination revealed dysarthria, a defect of the right-side visual field and accelerated right Achilles tendon reflex. A T2-weighted MRI showed a high-intensity signal in the white matter of the left parieto-occipital lobe surrounded by severe brain edema with a mass effect. The meninges around the lesion were enhanced by gadolinium, but no enhancement was observed in the basal portion. Angiotensin-converting enzyme (ACE) activities of cerebrospinal fluid (CSF) and serum were within normal range. The level of interleukin-6 in the CSF was slightly elevated. Chest X ray films and chest CT revealed no abnormal lesions. Whole body gallium scanning showed a hot region only in the intracranial lesion. A brain biopsy was performed. Histological examination revealed typical granuloma of sarcoidosis accompanied by microvasculitis and epithelioid cell granuloma without caseous necrosis. Oral administration of prednisolone improved all symptoms and MRI findings. These observations suggest that release of cytokines from macrophages and epithelioid cells, as well as disruption of the blood-brain barrier due to microvasculitis, are involved in the mechanism responsible for producing lesions of sarcoid meningoencephalitis.

Pro-carboxypeptidase R is an acute phase protein in the mouse, whereas carboxypeptidase N is not

Carboxypeptidase R (EC 3.4.17.20; CPR) and carboxypeptidase N (EC 3. 4.17.3; CPN) cleave carboxyl-terminal arginine and lysine residues from biologically active peptides such as kinins and anaphylatoxins, resulting in regulation of their biological activity. Human proCPR, also known as thrombin-activatable fibrinolysis inhibitor, plasma pro-carboxypeptidase B, and pro-carboxypeptidase U, is a plasma zymogen activated during coagulation. CPN, however, previously termed kininase I and anaphylatoxin inactivator, is present in a stable active form in plasma. We report here the isolation of mouse proCPR and CPN cDNA clones that can induce their respective enzymatic activities in culture supernatants of transiently transfected cells. Potato carboxypeptidase inhibitor can inhibit carboxypeptidase activity in culture medium of mouse proCPR-transfected cells. The expression of proCPR mRNA in murine liver is greatly enhanced following LPS injection, whereas CPN mRNA expression remains unaffected. Furthermore, the CPR activity in plasma increased 2-fold at 24 h after LPS treatment. Therefore, proCPR can be considered a type of acute phase protein, whereas CPN is not. An increase in CPR activity may facilitate rapid inactivation of inflammatory mediators generated at the site of Gram-negative bacterial infection and may consequently prevent septic shock. In view of the ability of proCPR to also inhibit fibrinolysis, an excess of proCPR induced by LPS may contribute to hypofibrinolysis in patients suffering from disseminated intravascular coagulation caused by sepsis.

Decay-accelerating factor in guinea pig stomachs following ischemia reperfusion stress

A complement regulatory protein, decay-accelerating factor (DAF, CD55), is known to protect host tissues from autologous complement activation. DAF is present on the apical side of human gastric epithelial cells, and its expression increases during gastritis. To develop an animal model for analysis of DAF expression on gastric cells, a mAb to guinea pig DAF was successfully used. Although DAF expression in the mucosal epithelium of the stomach is weak, as judged by immunohistochemical staining with the mAb, it was temporarily up-regulated at 12 and 24 h, and at 3 days after ischemia reperfusion (I/R) (p < 0.05). The DAF mRNA level in gastric tissues was determined by Northern blot analysis and found to be highest at 6 h after I/R, returning to the baseline at 24 h. Strong DAF mRNA expression was observed in the cytoplasm of cells beneath the eroded tissues 6 h after I/R. In guinea pigs, alternative splicing of DAF mRNA generates both GPI-anchored types and transmembrane types of DAF. RT-PCR analysis revealed that mRNAs of the transmembrane types had become significantly dominant by 6 h after I/R, whereas levels for the GPI-anchored types remained unchanged. In guinea pigs depleted of complement by cobra venom factor treatment, the area of erosion and the up-regulation of DAF expression in gastric epithelial cells after I/R were significantly limited compared with the normocomplementemic group, indicating that DAF may be up-regulated by an inflammatory stress.

Hippocampal cholinergic neurostimulating peptides (HCNP)

Neuronal development and differentiation require a variety of cell interactions. Diffusible molecules from target neurons play an important part in mediating such interactions. Our early studies used explant culture technique to examine the factors that enhance the differentiation of septo-hippocampal cholinergic neurons, and they revealed that several components resident in the hippocampus are involved in the differentiation of presynaptic cholinergic neurons in the medial septal nucleus. One of these components, originally purified from young rat hippocampus, is a novel undecapeptide (hippocampal cholinergic neurostimulating peptide; HCNP); this enhances the production of ChAT, but not of AchE. Later experiments revealed that: (1) a specific receptor appears to mediate this effect; (2) NGF and HCNP act cooperatively to regulate cholinergic phenotype development in the medial septal nucleus in culture; and (3) these two molecules differ both in their mechanism of release from the hippocampus and their mechanism of action on cholinergic neurons. The amino acid sequence deduced from base sequence analysis of cloned HCNP-precursor protein cDNA shows that HCNP is located at the N-terminal domain of its precursor protein. The 21 kDa HCNP precursor protein shows homology with other proteins, and it functions not only as an HCNP precursor, but also as a binding protein for ATP, opioids and phosphatidylethanolamine. The distribution and localization of HCNP-related components and the expression of their mRNAs support the notion that the precursor protein is multifunctional. In keeping with its multiple functions, the multiple enhancers and promoters found in the genomic DNA for HCNP precursor protein may be involved in the regulation of its gene in a variety of cells and at different stages of development. Furthermore, several lines of evidence obtained from studies of humans and animal models suggest that certain types of memory and learning disorders are associated with abnormal accumulation and expression of HCNP analogue peptide and/or its precursor protein mRNA in the hippocampus.

The natriuretic peptide clearance receptor locally modulates the physiological effects of the natriuretic peptide system

Natriuretic peptides (NPs), mainly produced in heart [atrial (ANP) and B-type (BNP)], brain (CNP), and kidney (urodilatin), decrease blood pressure and increase salt excretion. These functions are mediated by natriuretic peptide receptors A and B (NPRA and NPRB) having cytoplasmic guanylyl cyclase domains that are stimulated when the receptors bind ligand. A more abundantly expressed receptor (NPRC or C-type) has a short cytoplasmic domain without guanylyl cyclase activity. NPRC is thought to act as a clearance receptor, although it may have additional functions. To test how NPRC affects the cardiovascular and renal systems, we inactivated its gene (Npr3) in mice by homologous recombination. The half life of [125I]ANP in the circulation of homozygotes lacking NPRC is two-thirds longer than in the wild type, although plasma levels of ANP and BNP in heterozygotes and homozygotes are close to the wild type. Heterozygotes and homozygotes have a progressively reduced ability to concentrate urine, exhibit mild diuresis, and tend to be blood volume depleted. Blood pressure in the homozygotes is 8 mmHg (1 mmHg = 133 Pa) below normal. These results are consistent with the sole cardiovascular/renal function of NPRC being to clear natriuretic peptides, thereby modulating local effects of the natriuretic peptide system. Unexpectedly, Npr3 -/- homozygotes have skeletal deformities associated with a considerable increase in bone turnover. The phenotype is consistent with the bone function of NPRC being to clear locally synthesized CNP and modulate its effects. We conclude that NPRC modulates the availability of the natriuretic peptides at their target organs, thereby allowing the activity of the natriuretic peptide system to be tailored to specific local needs.

Increased expression of hippocampal cholinergic neurostimulating peptide-related components and their messenger RNAs in the hippocampus of aged senescence-accelerated mice

Hippocampal cholinergic neurostimulating peptide stimulates cholinergic phenotype development by inducing choline acetyltransferase in the rat medial septal nucleus in vitro. Adult senescence-accelerated-prone mice/8, a substrain of the senescence-accelerated-prone mouse, show a remarkable age-accelerated deterioration in learning and memory. We cloned mouse hippocampal cholinergic neurostimulating peptide precursor protein complementary DNA. The deduced amino acid sequence showed that the neurostimulating peptide itself is the same as that found in the rat. In situ hybridization revealed that the highest expression of the precursor protein messenger RNA was in hippocampal pyramidal neurons. Compared with a strain of senescence-accelerated-resistant mouse (control mouse), adult senescence-accelerated-prone mice/8 showed increased expression of both the precursor messenger RNA and the neurostimulating peptide-related immunodeposits in the hippocampal CA1 field. The deposits were intensely and diffusely precipitated in neuropils throughout the strata oriens and radiatum in senescence-accelerated-prone mice/8, but not in control mice. The neurostimulating peptide content in the hippocampus was higher in senescence-accelerated-prone mice/8 than in control mice, while its precursor protein itself was not different between the two strains. Furthermore, our previous and present data show that the medial septal and hippocampal choline acetyltransferase activity was significantly lower in senescence-accelerated-prone mice/8 than in control mice. The data suggest that, in hippocampal neurons in adult senescence-accelerated-prone mice/8, the production of hippocampal cholinergic neurostimulating peptide precursor protein in neuronal somata, which is associated with an increased expression of its messenger RNA in the CA1 field, occurs as a consequence of low activity in their presynaptic cholinergic neurons. This is followed by accelerated processing to generate bioactive peptide and transport to its functional fields. However, certain mechanisms reduce the release of the peptide and lead to its accumulation in the neuropil. These disturbances of the septohippocampal cholinergic system might be the biochemical mechanism underlying the characteristic deterioration of senescence-accelerated-prone mice/8.

High levels of hippocampal cholinergic neurostimulating peptide (HCNP) in the CSF of some patients with Alzheimer's disease

Hippocampal cholinergic neurostimulating peptide (HCNP), originally purified from the hippocampus of young rats, enhances the cholinergic development of rat medial septal nuclei in vitro. This report concerns the determination of the HCNP content of the cerebrospinal fluid (CSF) of 173 clinically, and of 22 clinico-pathologically defined patients. A radioimmunoassay was used throughout. The HCNP level was relatively uniform among the clinically defined patients; for almost all non-Alzheimer's patients, the level fell within the range delimited by +/- 2 SD of the mean for all patients taken together, and none of them had a level above this range. By contrast, the early-onset Alzheimer's disease patients could be divided on the basis of their HCNP level into two groups, one with high levels (markedly above the mean +/- 2SD range), and the other with levels similar to those of the other patients. The analysis of the CSF samples obtained postmortem revealed that Group I Alzheimer-type dementia (ATD) patients with clinico-pathologically established diagnoses had a strikingly higher level of HCNP than patients with either Group II ATD or cerebral vascular disease. These results suggest that HCNP is involved in certain pathophysiological alterations associated with dementia, and that its determination may be useful in patient evaluation. Copyright 1998 Lippincott Williams & Wilkins

[A case of clinically diagnosed Creutzfeldt-Jakob disease with serial MRI diffusion weighted images]

We reported MRI findings in a 49-year-old woman with clinically diagnosed Creutzfeldt-Jakob disease (CJD). She was admitted to our hospital because of confusion, which initially appeared 5 weeks prior and was rapidly worsened. Two weeks later, she developed myoclonic jerks in her extremities with periodic synchronous discharges on EEG. Six months later, she became mutic. Brain MRI at 3 weeks after the admission demonstrated high signal intensities in the bilateral caudate nuclei and putamina on T2 weighted images (T2WIs). Diffusion weighted images (DWIs) showed hyperintensities in the basal ganglia and in the parietal and occipital cortices. Five weeks later, the abnormal intensities in the basal ganglia were still observed on T2WIs but decreased on DWIs. Five months later, the increased signal intensities in the basal ganglia had disappeared both on T2WIs and DWIs, but new hyperintensities appeared in the insula and the temporal area on DWIs. We concluded that DWIs may be useful for the demonstrations of a lesion in the cerebral cortex and the spread of lesions.

An unusual course of progressive multifocal leukoencephalopathy in a patient with idiopathic CD4+ T lymphocytopenia

A case is reported of idiopathic CD4+T lymphocytopenia with progressive multifocal leukoencephalopathy and cervical lymph node tuberculosis. A 57 year old Japanese man presented with cervical lymphadenopathy and progressive neurological deficits, and six months later he developed akinetic mutism. He had a persistent severely depressed number of circulating CD4+T lymphocytes in the absence of human immunodeficiency virus infection. T1 weighted MRI showed a diffuse decreased signal intensity limited to the white matter without mass effect. A brain biopsy specimen had a morphology similar to that of progressive multifocal leukoencephalopathy. Polyomavirus antigen was detected in the brain lesion, and viral DNA was identified in nucleated blood cells and urine. Unusually this serious medical condition has lasted for more than three years without remission. To our knowledge this is the first patient with CD4+T lymphocytopenia with progressive multifocal leukoencephalopathy, suggesting that similar opportunistic infections should be considered even in previously normal people.

Possible implication of hippocampal cholinergic neurostimulating peptide (HCNP)-related components in Hirano body formation

We have previously demonstrated that hippocampal cholinergic neurostimulating peptide (HCNP)-related components accumulate in almost all Hirano bodies in Sommer's sector of the hippocampus of elderly individuals, and that the number of HCNP-positive Hirano bodies is greater in patients with Alzheimer's disease. Although Hirano bodies occur preferentially in the neuronal processes of the stratum pyramidale of the hippocampus, they can be seen occasionally as small inclusions, intermingled with neurofibrillary tangles and in association with senile plaques. Here we show that the small inclusions are also recognized by an anti-HCNP antibody, and by using immunoelectron microscopy demonstrate that these HCNP-positive inclusions, intermingled with tau protein-positive neurofibrillary tangles and beta-amyloid-positive senile plaques are indeed Hirano bodies. These findings strongly suggest that HCNP-related components may be involved in Hirano body formation.