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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ydbio.2006.03.038 Byline: Chang-Hoon Choi, Beom-Jun Kim, Sun-Young Jeong, Chang-Hun Lee, Ji-Sun Kim, Seong-Jun Park, Hyung-Soon Yim, Sa-Ouk Kang Keywords: Glutaredoxin; Glutathione reductase; Glutathione; Culmination; Cell fate; Dictyostelium discoideum Abstract: Glutaredoxins have been known to be glutathione-dependent oxidoreductases that participate in the redox regulation of various cellular processes. To understand the role of glutaredoxins in the development, we examined glutaredoxin 1 (Grx1) of Dictyostelium discoideum. Its mRNA was highly accumulated at the mound and the culmination stages. When Grx1-overexpressing cells were developed, their culmination was delayed, and the expression of marker genes for prespore and spore decreased. Interestingly, they had about 1.5-fold higher amount of reduced glutathione (GSH) compared with parental cells and their prolonged migration was repressed by the oxidant such as hydrogen peroxide. To confirm the effect of GSH on the culmination, glutathione reductase (Gsr) was overexpressed or underexpressed. Similar to Grx1-overexpressing cells, Gsr-overexpressing cells contained about 1.5-fold higher amount of GSH and exhibited the delayed culmination. In contrast, the knockdown mutant of Gsr had nearly 50% lower amount of GSH and showed accelerated culmination. Taken together, these data suggest that the culmination of Dictyostelium is controlled by GSH. In addition, the cells having higher GSH levels showed a prestalk tendency in the chimeric slugs with parental cells, indicating that the difference in the amount of GSH may affect the determination of cell fate. Author Affiliation: Laboratory of Biophysics, School of Biological Sciences, and Institute of Microbiology, Seoul National University, Seoul 151-742, Republic of Korea Article History: Received 19 November 2005; Revised 4 March 2006; Accepted 28 March 2006

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ydbio.2005.05.034 Byline: Beom-Jun Kim, Chang-Hoon Choi, Chang-Hun Lee, Sun-Young Jeong, Ji-Sun Kim, Bo-Yeon Kim, Hyung-Soon Yim, Sa-Ouk Kang Keywords: Glutathione; [gamma]-Glutamylcysteine synthetase; Cell fate; Dictyostelium discoideum Abstract: Glutathione (GSH) is the most abundant non-protein thiol in eukaryotic cells and acts as reducing equivalent in many cellular processes. We investigated the role of glutathione in Dictyostelium development by disruption of [gamma]-glutamylcysteine synthetase (GCS), an essential enzyme in glutathione biosynthesis. GCS-null strain showed glutathione auxotrophy and could not grow in medium containing other thiol compounds. The developmental progress of GCS-null strain was determined by GSH concentration contained in preincubated media before development. GCS-null strain preincubated with 0.2 mM GSH was arrested at mound stage or formed bent stalk-like structure during development. GCS-null strain preincubated with more than 0.5 mM GSH formed fruiting body with spores, but spore viability was significantly reduced. In GCS-null strain precultured with 0.2 mM GSH, prestalk-specific gene expression was delayed, while prespore-specific gene and spore-specific gene expressions were not detected. In addition, GCS-null strain precultured with 0.2 mM GSH showed prestalk tendency and extended G1 phase of cell cycle. Since G1 phase cells at starvation differentiate into prestalk cells, developmental defect of GCS-null strain precultured with 0.2 mM GSH may result from altered cell cycle. These results suggest that glutathione itself is essential for growth and differentiation to prespore in Dictyostelium. Author Affiliation: Laboratory of Biophysics, School of Biological Sciences, and Institute of Microbiology, Seoul National University, Seoul 151-742, Republic of Korea Article History: Received 30 November 2004; Revised 30 March 2005; Accepted 25 May 2005

Myasthenia gravis (MG) is a chronic autoimmune neuromuscular disease. Vitamin D has important roles both in the autoimmune response and in skeletal muscles. We investigated the levels of 1,25-dihydroxy vitamin D [1,25(OH) 2 D] and 25-hydroxy vitamin D [25(OH)D] in patients with MG and healthy subjects. MG patients were classified by disease stage, age of onset and treatment status whether or not to taking immunosuppressive agents. MG patients had lower plasma 25(OH)D levels (mean, 18.8 ± 8.4 ng/mL) than healthy controls (26.3 ± 6.1 ng/mL) (p < .05). 1,25(OH) 2 D levels showed slightly high in MG patients than healthy controls, but had no significant difference between two groups. In addition, no significant differences were observed between two groups divided by clinical characteristics. Serum 25(OH)D levels significantly lower in patients with MG compared with healthy controls. We recommend monitoring of vitamin D status in patients with MG to avoid direct negative effects on the muscles or autoimmune response. [ABSTRACT FROM AUTHOR]

Background: To examine changing patterns in arterial stiffness and functional outcome in patients with subacute stroke, and to determine which parameter shows a strong correlation with the reversal of arterial stiffness, during a 3-month period of comprehensive rehabilitation therapy.Methods: This descriptive, observational cohort study enrolled 60 patients (43 male and 17 female; average age, 62.7 years), and all received conventional rehabilitation therapy, during a 3-month period. Brachial-ankle pulse wave velocity (baPWV) was measured as an index of arterial stiffness. Functional assessments included the 6-minute walk test (6MWT), Fugl-Meyer Assessment of hemiparetic upper and lower limbs, the functional ambulatory category, the Berg balance scale, the Korean Mini-Mental Status Examination, and the Korean-Modified Barthel Index. All measurements were conducted at baseline and 1 and 3 months after stroke onset.Results: Rehabilitation therapy resulted in a statistically significant improvement in baPWV since 3 months post stroke. Another functional outcome measure showed statistically significant improvements since 1 month after rehabilitation. Multivariable linear regression analysis revealed that a change in baPWV was significantly correlated with changes in the 6MWT.Conclusions: Three months of comprehensive rehabilitation therapy led to statistically significant improvements in arterial stiffness and functional outcomes during the subacute phase of stroke. Thus, the comprehensive rehabilitation focused on improving gait endurance would be warranted in subacute stroke patients. [ABSTRACT FROM AUTHOR]

Background: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a single-gene disorder of cerebral small blood vessels caused by mutations in the NOTCH3 gene. The initial detection of CADASIL may be more difficult among Asian populations because common clinical phenotypes and neuroimaging findings are not frequently found in these populations. The purpose of this study was to screen the NOTCH3 gene for mutations among consecutive patients with acute ischemic stroke from our region in Korea. Methods: Between April 2008 and March 2009, 151 consecutive patients with acute ischemic stroke were screened for NOTCH3 mutations. All patients underwent a detailed clinical examination and structured interview for clinical symptoms and family history. We reviewed brain magnetic resonance imaging data from stroke patients to assess the severity of white-matter hyperintensity lesions, the number of cerebral microbleeds, and the number of lacunar infarctions. Polymerase chain reaction was used to screen exons 3, 4, 6, 11, and 18 of the NOTCH3 gene. Results: Among 151 consecutive patients with acute ischemic stroke, 6 patients (4.0%; 95% confidence interval [CI] 0.9-7.1) possessed a NOTCH3 gene mutation. All patients exhibited the same R544C mutation in exon 11. Four of these 6 patients presented with large artery atherosclerosis. The prevalence of CADASIL in patients with neuroimaging features consistent with advanced small-vessel disease was 36.0% (95% CI 8.0-64.8). Conclusions: In this region, NOTCH3 gene mutations are frequently found in acute stroke patients who present with neuroimaging features consistent with advanced small-vessel disease. [Copyright &y& Elsevier]

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a single-gene disorder of the cerebral small blood vessels caused by mutations in the NOTCH3 gene. Several characteristic population-specific clinical phenotypes and neuroimaging features have been reported in CADASIL. This study investigated the clinical stroke presentation and cranial magnetic resonance imaging (MRI) findings in a group of patients with CADASIL. We reviewed the clinical stroke presentation and brain MRI findings in 73 consecutive Korean patients aged >18 years diagnosed with CADASIL between May 2004 and April 2009. Brain MRI images were also scored for lacunar infarction and cerebral microbleeds. Intracranial atherosclerosis (ICAS) was assessed by magnetic resonance angiography. Disability was measured with the modified Rankin scale (mRS) and classified as good (mRS score 0-2) or poor (mRS score 3-5). In this study, 65 of the 73 patients (90.3%) had the same R544C genotype. A total of 40 episodes of cerebral infarction were confirmed in 31 patients, with a mean age at onset of 58.8 ± 11.4 years (range, 38-76 years). Twelve patients (16.9%) had ICAS, and 5 of these patients had symptomatic stenoses. Intracerebral hemorrhage occurred in 9 patients (12.3%). Both intracerebral hemorrhage and ICAS were associated with poor clinical outcome. Our data demonstrate the diversity of clinical stroke presentation according to ethnicity and vascular risk factors. [ABSTRACT FROM AUTHOR]

Hereditary progressive dystonia with marked diurnal fluctuation/dopa-responsive dystonia (HPD/DRD) shows the considerable heterogeneity of clinical phenotypic expression and a dramatic sustained response to levodopa. The autosomal dominant HPD/DRD is caused by mutations in the gene coding GTP cyclohydrolase I (GCH I), the enzyme that catalyzes the first step in the biosynthesis of tetrahydrobiopterin. Previous studies suggested that normal [18F]Dopa positron emission tomography or [123I]β-CIT single-photon emission computed tomography (SPECT) imaging, indicating intact structural integrity of nigrostriatal neurons, may be useful for differentiating HPD/DRD from clinically similar conditions such as juvenile Parkinson''s disease with dystonia that have a considerably poorer prognosis. We here report a Korean family affected with HPD/DRD due to a novel missense mutation of the GCH I gene (T→G mutation in exon 2), Met 137 Arg, which may change the conformation of the binding site of GCH I. The clinical features are considerably variable within the family. We documented normal striatal uptake of [123I]IPT, a dopamine transporter ligand with fast washout kinetics, in our patients by using SPECT. This method can be helpful in diagnosing HPD/DRD in uncertain cases. [Copyright &y& Elsevier]

The antimicrobial activity of lactic acid bacteria (LAB) is well recognized, particularly because they can produce antimicrobial cyclic dipeptides (CDPs). CDPs serve as attractive scaffolds for drug design owing to the structural variety of their chiral side chains. Using filtrates from fermented kimchi produced using Leuconostoc mesenteroides LBP-K06 starter cultures, we previously demonstrated a combined chromatographic fractionation and gas chromatography-mass spectroscopy method for screening bioactive CDPs. However, the entire pool of CDPs from a given lactic acid bacterial culture is not fully understood. The present study identified the CDP produced by Lactobacillus plantarum LBP-K10, which was the most potent antimicrobial isolated from Korean kimchi. In total, 15 CDPs containing proline and a single CDP without proline were identified in the culture filtrates (CFs) using gas chromatography-mass spectroscopy (GC-MS). These CDPs were also commonly found in the CFs from other isolated LAB. We developed a new method for purifying a massive amount of complete sets of CDPs from CFs using the anion exchange resins Amberlite IRA-67, Purolite A420S, or both. Compared with the activities of the individual CDPs, the entire set showed remarkable potency including bioactivities against multidrug-resistant Gram-positive and Gram-negative bacteria, human and plant pathogenic fungi, and the influenza A virus (H3N2). We demonstrated that the combination of 16 CDPs naturally produced by one organism exhibited strong antimicrobial activity. This novel strategy for profiling metabolites would enable more effective assessments of fermented foods and LAB. [ABSTRACT FROM AUTHOR]

Background High methylglyoxal content disrupts cell physiology, but mammals have scavengers to prevent glycolytic and mitochondrial dysfunctions. In yeast, methylglyoxal accumulation triggers methylglyoxal-oxidizing alcohol dehydrogenase (Adh1) activity. While methylglyoxal reductases and glyoxalases have been well studied in prokaryotes and eukaryotes, experimental evidence for methylglyoxal dehydrogenase (Mgd) and other catalytic activities of this enzyme affecting glycolysis and the tricarboxylic acid cycle is lacking. Methods A glycine-rich cytoplasmic Mgd protein, designated as Mgd1/Grp2, was isolated from glutathione-depleted Candida albicans . The effects of Mgd1/Grp2 activities on metabolic pathophysiology were investigated using knockout and overexpression mutants. We measured glutathione-(in)dependent metabolite contents and metabolic effects, including viability, oxygen consumption, ADH1 transcripts, and glutathione reductase and α-ketoglutarate dehydrogenase activities in the mutants. Based on the findings, methylglyoxal-oxidizing proteins were monitored to determine effects of MGD1 / GRP2 disruption on methylglyoxal-scavenging traits during glutathione deprivation. Results Methylglyoxal-oxidizing NAD(H)-linked Mgd1/Grp2 was found solely in glutathione auxotrophs, and it catalyzed the reduction of both methylglyoxal and pyruvate. MGD1 / GRP2 disruptants showed growth defects, cell-cycle arrest, and methylglyoxal and pyruvate accumulation with mitochondrial impairment, regardless of ADH1 compensation. Other methylglyoxal-oxidizing enzymes were identified as key glycolytic enzymes with enhanced activity and transcription in MGD1 / GRP2 disruptants, irrespective of glutathione content. Conclusions Failure of methylglyoxal and pyruvate dissimilation by Mgd1/Grp2 deficiency leads to poor glutathione-dependent redox regulation despite compensation by Adh1. General significance This is the first report that multifunctional Mgd activities contribute to scavenging methylglyoxal and pyruvate to maintain metabolic homeostasis and the redox pool via glycolytic enzymes and Adh1 expression. [ABSTRACT FROM AUTHOR]

Polyamines protect protein glycation in cells against the advanced glycation end product precursor methylglyoxal, which is inevitably produced during glycolysis, and the enzymes that detoxify this α-ketoaldehyde have been widely studied. Nonetheless, nonenzymatic methylglyoxal-scavenging molecules have not been sufficiently studied either in vitro or in vivo . Here, we hypothesized reciprocal regulation between polyamines and methylglyoxal modeled in Dictyostelium grown in a high-glucose medium. We based our hypothesis on the reaction between putrescine and methylglyoxal in putrescine-deficient ( odc − ) or putrescine-overexpressing ( odc oe ) cells. In these strains, growth and cell cycle were found to be dependent on cellular methylglyoxal and putrescine contents. The odc − cells showed growth defects and underwent G1 phase cell cycle arrest, which was efficiently reversed by exogenous putrescine. Cellular methylglyoxal, reactive oxygen species (ROS), and glutathione levels were remarkably changed in odc oe cells and odc ̄ cells. These results revealed that putrescine may act as an intracellular scavenger of methylglyoxal and ROS. Herein, we observed interactions of putrescine and methylglyoxal via formation of a Schiff base complex, by UV–vis spectroscopy, and confirmed this adduct by liquid chromatography with mass spectrometry via electrospray ionization. Schiff bases were isolated, analyzed, and predicted to have molecular masses ranging from 124 to 130. We showed that cellular putrescine–methylglyoxal Schiff bases were downregulated in proportion to the levels of endogenous or exogenous putrescine and glutathione in the odc mutants. The putrescine–methylglyoxal Schiff base affected endogenous metabolite levels. This is the first report showing that cellular methylglyoxal functions as a signaling molecule through reciprocal interactions with polyamines by forming Schiff bases. [ABSTRACT FROM AUTHOR]

Reduced glutathione (GSH) is an essential metabolite that performs multiple indispensable roles during the development of Dictyostelium. We show here that disruption of the gene (gcsAŵ) encoding γ-glutamylcysteine synthetase, an essential enzyme in GSH biosynthesis, inhibited aggregation, and that this developmental defect was rescued by exogenous GSH, but not by other thiols or antioxidants. In GSH-depleted gcsAŵ cells, the expression of a growth-stage-specific gene (cprD) was not inhibited, and we did not detect the expression of genes that encode proteins required for early development (cAMP receptor, carA/cAR1; adenylyl cyclase, acaA/ACA; and the catalytic subunit of protein kinase A, pkaC/PKA-C). The defects in gcsAŵ cells were not restored by cAMP stimulation or by cAR1 expression. Further, the expression of yakA, which initiates development and induces the expression of PKA-C, ACA, and cAR1, was regulated by the intracellular concentration of GSH. Constitutive expression of YakA in gcsAŵcells (YakAOE/gcsAŵ) rescued the defects in developmental initiation and the expression of early developmental genes in the absence of GSH. Taken together, these findings suggest that GSH plays an essential role in the transition from growth to development by modulating the expression of the genes encoding YakA as well as components that act downstream in the YakA signaling pathway. [ABSTRACT FROM AUTHOR]

Abstract: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary disease characterized by ischemic stroke, cognitive impairment, migraine and neuropsychological deficit. Although intracerebral hemorrhage (ICH) has been described in patients with CADASIL, the cause of such ICH is still unknown. We present a 39-year-old man with CADASIL who had two years history of untreated hypertension. In this patient, acute ICH developed only two weeks after the initiation of aspirin. Brain images demonstrated a 3cm×3cm hyperacute ICH in the left temporal lobe at the site of previous old hemorrhage. The presence of cerebral microbleed and use of antithrombotics may be associated with development of ICH in patients with CADASIL. [Copyright &y& Elsevier]

D-erythroascorbate peroxidase ( EAPX1 ) deficiency causes glutathione deprivation, leading to the accumulation of methylglyoxal and reactive oxygen species (ROS), and especially, induction of cytochrome c peroxidase (Ccp1) in Candida albicans . Nevertheless, reciprocal effects between changes in Ccp1 activity and the antioxidative D-erythroascorbic acid- and glutathione-dependent redox status, which reflects methylglyoxal biosynthesis altering pathophysiology are unclear in eukaryotes. To elucidate the effect of CCP1 expression on EAPX1 and glutathione reductase (Glr1) activity-mediated D-erythroascorbic acid biosynthesis and redox homeostasis, the CCP1 gene was disrupted and overexpressed. First, we demonstrated both glutathione-independent and-dependent metabolite contents and their corresponding gene transcripts and enzyme activities (i.e., Ccp1, catalase-peroxidase [KatG], superoxide dismutase [Sod], Eapx1, and Glr1) in CCP1 mutants. Second, methylglyoxal-oxidizing alcohol dehydrogenase (Adh1) and methylglyoxal-reducing oxidoreductase activity on glycolytic methylglyoxal and pyruvate production and NAD(P)H content were determined in these mutants. Contrary to our expectation, CCP1 disruption (42.19 ± 3.22 nmol O 2 h −1 mg wet cell −1 ) failed to affect cell respiration compared to the wild-type strain (41.62 ± 7.11 nmol O 2 h −1 mg wet cell −1 ) under cyanide treatment, and in contrast to hydrogen peroxide (H 2 O 2 ) treatment (21.74 ± 1.03 nmol O 2 h −1 mg wet cell −1 ). Additionally, Ccp1 predominantly detoxified H 2 O 2 rather than negligible scavenging activities towards methylglyoxal and other oxidants. CCP1 deficiency stimulated Sod and Adh1 activity but downregulated Glr1, Eapx1, catalase, and peroxidase activity while enhancing KatG , EAPX1 , and GLR1 transcription by decreasing glutathione and D-erythroascorbic acid and increasing pyruvate. Noticeably, the ROS-accumulating CCP1- deficient mutant maintained steady-state levels of methylglyoxal, which was revealed to be regulated by methylglyoxal-oxidizing and −reducing activity with drastic changes in NAD(P)H. We confirmed and clarified our results by showing that CCP1/EAPX1 double disruptants underwent severe growth defects due to the D-erythroascorbic acid and glutathione depletion because of pyruvate overaccumulation. These observations were made in both budding and hyphal-growing CCP1 mutants. The revealed metabolic network involving Ccp1 and other redox regulators affected ROS and methylglyoxal through D-erythroascorbic acid and glutathione-dependent metabolites, thereby influencing dimorphism. This is the first report of the Ccp1-mediated D-erythroascorbic acid and glutathione biosynthesis accompanying methylglyoxal scavengers for full fungal virulence. [ABSTRACT FROM AUTHOR]

Methylglyoxal regulates cell division and differentiation through its interaction with polyamines. Loss of their biosynthesizing enzyme causes physiological impairment and cell elongation in eukaryotes. However, the reciprocal effects of methylglyoxal and polyamine production and its regulatory metabolic switches on morphological changes in prokaryotes have not been addressed. Here, Bacillus subtilis methylglyoxal synthase ( mgsA ) and polyamine biosynthesizing genes encoding arginine decarboxylase (SpeA), agmatinase (SpeB), and spermidine synthase (SpeE), were disrupted or overexpressed. Treatment of 0.2 mM methylglyoxal and 1 mM spermidine led to the elongation and shortening of B. subtilis wild-type cells to 12.38 ± 3.21 μm ( P < 0.05) and 3.24 ± 0.73 μm ( P < 0.01), respectively, compared to untreated cells (5.72 ± 0.68 μm). mgsA -deficient ( mgsA − ) and -overexpressing ( mgsA OE ) mutants also demonstrated cell shortening and elongation, similar to speB - and speE -deficient ( speB − and speE − ) and -overexpressing ( speB OE and speE OE ) mutants. Importantly, both mgsA -depleted speB OE and speE OE mutants ( speB OE / mgsA − and speE OE / mgsA − ) were drastically shortened to 24.5% and 23.8% of parental speB OE and speE OE mutants, respectively. These phenotypes were associated with reciprocal alterations of mgsA and polyamine transcripts governed by the contents of methylglyoxal and spermidine, which are involved in enzymatic or genetic metabolite-control mechanisms. Additionally, biophysically detected methylglyoxal-spermidine Schiff bases did not affect morphogenesis. Taken together, the findings indicate that methylglyoxal triggers cell elongation. Furthermore, cells with methylglyoxal accumulation commonly exhibit an elongated rod-shaped morphology through upregulation of mgsA , polyamine genes, and the global regulator spx , as well as repression of the cell division and shape regulator, FtsZ. [ABSTRACT FROM AUTHOR]

Glutathione (GSH)-deprived Dictyostelium discoideum accumulates methylglyoxal (MG) and reactive oxygen species (ROS) during vegetative growth. However, the reciprocal effects of the production and regulation of these metabolites on differentiation and cell motility are unclear. Based on the inhibitory effects of γ-glutamylcysteine synthetase ( gcsA ) disruption and GSH reductase ( gsr ) overexpression on aggregation and culmination, respectively, we overexpressed GSH-related genes encoding superoxide dismutase (Sod2), catalase (CatA), and Gcs, in D. discoideum . Wild-type KAx3 and gcsA -overexpressing ( gcsA OE ) slugs maintained GSH levels at levels of approximately 2.1-fold less than the reference GSH synthetase-overexpressing mutant; their GSH levels did not correlate with slug migration ability. Through prolonged KAx3 migration by treatment with MG and H 2 O 2 , we found that MG increased after the mound stage in this strain, with a 2.6-fold increase compared to early developmental stages; in contrast, ROS were maintained at high levels throughout development. While the migration-defective sod2 - and catA -overexpressing mutant slugs ( sod2 OE and catA OE ) decreased ROS levels by 50% and 53%, respectively, these slugs showed moderately decreased MG levels (36.2 ± 5.8 and 40.7 ± 1.6 nmol g −1 cells wet weight, P < 0.05) compared to the parental strain (54.2 ± 3.5 nmol g −1 ). Importantly, defects in the migration of gcsA OE slugs decreased MG considerably (13.8 ± 4.2 nmol g −1 , P < 0.01) along with a slight decrease in ROS. In contrast to the increase observed in migrating sod2 OE and catA OE slugs by treatment with MG and H 2 O 2 , the migration of gcsA OE slugs appeared unaffected. This behavior was caused by MG-triggered Gsr and NADPH-linked aldolase reductase activity, suggesting that GSH biosynthesis in gcsA OE slugs is specifically used for MG-scavenging activity. This is the first report showing that MG upregulates slug migration via MG-scavenging-mediated differentiation. [ABSTRACT FROM AUTHOR]

Introduction Several clinical studies using tacrolimus revealed reasonable therapeutic mechanisms and efficacy in patients with myasthenia gravis (MG). However, long-period studies in a large number of patients with MG are limited; therefore, the aim of this study was to investigate the therapeutic efficacies and safety of tacrolimus in patients with MG during a 12-month follow-up period. Methods Tacrolimus was administered to 150 patients with MG who were recruited based on the inclusion criteria. Fifteen medical centers in Korea participated in this study. The efficacy of tacrolimus was assessed using MG composite scales (MGCS) and the prednisolone-sparing effect. And the adverse drug reactions (ADRs) of tacrolimus were monitored in each patient from the beginning of tacrolimus treatment to the end of the follow-up period. Results After starting tacrolimus, the 32 patients were affected by ADRs, and consequentially 134 patients of the enrolled patients were followed up for 12 months. They showed that the mean prednisolone dosage significantly decreased (6.1 ± 7.6 mg/day), compared to that in the baseline (11.3 ± 9.5 mg/day), and MGCS significantly improved after 12 months of tacrolimus treatment, compared to that at the baseline. Conclusions Our study showed that tacrolimus would be an effective immunosuppressant as an initial therapeutic agent in patients with MG; in addition, it showed tolerable safety profiles during the 12-month follow-up evaluation. [ABSTRACT FROM AUTHOR]

Azathioprine (AZA)-induced leukopenia is a relatively common complication in Korean patients. In addition to variation in TPMT (thiopurine S -methyltransferase), the NUDT15 p.R139C variant was recently identified to have a strong association with AZA-induced leukopenia. We investigated these associations in Korean patients undergoing AZA treatment with various neurological diseases. Among 84 enrolled patients, 20 (23.8%; 7 early, 13 late) exhibited leukopenia. The NUDT15 p.R139C variant was associated with leukopenia (OR: 11.844, 95% CI 3.984–36.024, p = 1.327 × 10 −5 ). The allelic frequency of NUDT15 p.R139C was as high as 10.7% and the frequency of the C/C, C/T, and T/T genotypes was 84.5, 10.7, and 5.9%, respectively. All T/T homozygous patients (5/5) developed early severe-grade leukopenia (white blood cells < 1000 mm −3 ) and severe alopecia. NUDT15 p.R139C was strongly associated with early leukopenia and severe alopecia (OR for early leukopenia: 107.624, 95% CI 18.857–614.250, p = 1.403 × 10 −7 , OR for severe alopecia: 77.152, 95% CI 17.378–342.526, p = 1.101 × 10 −8 ). The sensitivity and specificity for predicting AZA-induced early leukopenia were 85.7% and 92.2%, respectively. Therefore, the NUDT15 p.R139C variant is common and strongly associated with AZA-induced early leukopenia and severe alopecia in Korean patients with various neurological diseases. [ABSTRACT FROM AUTHOR]

Background Glutathione reductase maintains the glutathione level in a reduced state. As previously demonstrated, glutathione is required for cell growth/division and its biosynthesizing-enzyme deficiency causes methylglyoxal accumulation. However, experimental evidences for reciprocal relationships between Cph1-/Efg1-mediated signaling pathway regulation and methylglyoxal production exerted by glutathione reductase on yeast morphology remain unclear. Methods Glutathione reductase ( GLR1 ) disruption/overexpression were performed to investigate aspects of pathological/morphological alterations in Candida albicans . These assumptions were proved by observations of cellular susceptibility to oxidants and thiols, and measurements of methylglyoxal and glutathione content in hyphal-inducing conditions mainly through the activity of GLR1 -overexpressing cells. Additionally, the transcriptional/translational levels of bioenergetic enzymes and dimorphism-regulating protein kinases were examined in the strain. Results The GLR1 -deficient strain was non-viable when GLR1 expression under the control of a CaMAL2 promoter was conditionally repressed, despite partial rescue of growth by exogenous thiols. During filamentation, non-growing hyphal GLR1 -overexpressing cells exhibited resistance against oxidants and cellular methylglyoxal was significantly decreased, which concomitantly increased expressions of genes encoding energy-generating enzymes, including fructose-1,6-bisphosphate aldolase, glyceraldehyde-3-phosphate dehydrogenase, and alcohol dehydrogenase (ADH1), with remarkable repression of Efg1-signaling cascades. Conclusions This is the first report that GLR1 -triggered Efg1-mediated signal transduction repression strictly reduces dimorphic switching and virulence by maintaining the basal level of methylglyoxal following the enhanced gene expressions of glycolytic enzymes and ADH1 . General significance The Efg1 downregulatory mechanism by GLR1 expression has possibilities to involve in other complex network of signal pathways. Understanding how GLR1 overexpression affects multiple signaling pathways can help identify attractive targets for antifungal drugs. [ABSTRACT FROM AUTHOR]

Abstract: Calcium-binding protein 3 (CBP3) expression was up-regulated under the control of the actin 15 promoter and down-regulated by RNA interference in Dictyostelium discoideum. The overexpression of CBP3 accelerated cell aggregation and formed small aggregates and fruiting body. CBP3-inhibited cells showed uneven aggregation and increased slug trail lengths toward the directed light, whereas CBP3-overexpressing cells showed the opposite phenomena. Under dark condition, the enhanced slug trail length was also observed in the CBP3-inhibited cells. Yeast two-hybrid screening identified actin 8 as interacting protein with CBP3. The interaction between CBP3 and actin was confirmed by β-galactosidase assay and surface plasmon resonance. CBP3 was associated with Triton X-100-insoluble cytoskeleton in the presence of Ca2+ and the interaction of CBP3 with cytoskeleton was increased by the addition of Ca2+. Using fluorescence microscopy, CBP3 was also shown to associate with the actin cytoskeleton during development. Subcellular fractionation indicated that CBP3 was enriched in cytosolic fraction. Taken together, these results suggest that CBP3 interacts with actin cytoskeleton and has a role during cell aggregation and slug migration of Dictyostelium. [Copyright &y& Elsevier]