Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder involving an extensive loss of motoneurons. Aberrant excitability of motoneurons has been implicated in the pathogenesis of selective motoneuronal death in ALS. D-Serine, an endogenous coagonist of N-methyl-D-aspartate receptors, exacerbates motoneuronal death and is increased both in patients with sporadic/ familial ALS and in a G93A-SOD1 mouse model of ALS (mSOD1 mouse). More recently, a unique mutation in the D-amino acid oxidase (DAO) gene, encoding a D-serine degrading enzyme, was reported to be associated with classical familial ALS. However, whether DAO affects the motoneuronal phenotype and D-serine increase in ALS remains uncertain. Here, we show that genetic inactivation of DAO in mice reduces the number and size of lower motoneurons with axonal degeneration, and that suppressed DAO activity in reactive astrocytes in the reticulospinal tract, one of the major inputs to the lower motoneurons, predominantly contributes to the D-serine increase in the mSOD1 mouse. The DAO inactivity resulted from expressional down-regulation, which was reversed by inhibitors of a glutamate receptor and MEK, but not by those of inflammatory stimuli. Our findings provide evidence that DAO has a pivotal role in motoneuron degeneration through D-serine regulation and that inactivity of DAO is a common feature between the mSOD1 ALS mouse model and the mutant DAO-associated familial ALS. The therapeutic benefit of reducing D-serine or controlling DAO activity in ALS should be tested in future studies.excitotoxicity | motor neuron disease | neurodegeneration | enzyme histochemistry | 2D-HPLC A myotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder characterized by selective loss of motoneurons in the spinal cord and brain leading to fatal paralysis. Approximately 90% of all cases are sporadic, and the remaining cases are inherited. Of inherited cases, 20% are associated with mutations in superoxide dismutase 1 (SOD1), and 10% involves 43-kDa transactivation response DNA-binding protein (TDP-43) and fused in sarcoma/translocated in liposarcoma (FUS/TLS). Despite extensive studies of previously identified ALS-causing genes, the mechanism underlying the selective motoneuronal loss in ALS remains uncertain. Given that the mechanism is at least, in part, common between sporadic and familial ALS, identification of the common pathology is a clue to conquering ALS. Among numerous etiological hypotheses, motoneuronal vulnerability to excitotoxicity is one of the most intensely investigated targets for the treatment of ALS because it is observed in both sporadic and familial ALS with SOD1 mutations (1, 2). For motoneurons, glutamate is the main excitatory transmitter, and excessive motoneuron excitability by glutamate through ionotropic glutamate receptors has been demonstrated.The N-methyl-D-aspartate (NMDA) receptor (NMDAR) is a subtype of the ionotropic glutamate receptors and exhibits relatively higher permeability to the calcium ion (Ca ...
The demographic features of 415 patients seeking cosmetic surgery were investigated from a psychiatric point of view. Of the 415 patients, 198 (47.7%) were found to have mental disorders according to ICD-10 including: 17 with schizophrenia, 20 with other persistent delusional disorders, 33 with depressive episode, 47 with neurotic disorders, 42 with hypochondriacal disorder, ®ve with paranoid personality disorder and 14 with histrionic personality disorder. The rate of subjects with poor social adjustment was 56.0%. It was noteworthy that such a considerable number of patients with mental disorders or with poor social adjustment had sought cosmetic surgery. Distinct gender differences were found: male subjects were characterized to have a greater number of mental disorders, especially dysmorphophobia (other persistent delusional disorders plus hypochondriacal disorder) and showed the narrow age range between teenage and young adult age when they were preoccupied with their`deformity', and poor social function. A history of frequent operations was not considered to be an indicator for mental abnormality. The diagnostic issue in dysmorphophobia is brie¯y described.
Genetic variability in the renin-angiotensin system may modify renal responses to injury and disease progression. We examined whether the M235T polymorphism of the angiotensinogen (AGT) gene, the insertion/deletion polymorphism of the angiotensin-converting enzyme (ACE) gene, and the A 1166 → C polymorphism of the angiotensin II type 1 receptor gene may be associated with disease progression in 168 Caucasian patients with IgA nephropathy. All patients had serial measurements of their creatinine clearance, proteinuria, and blood pressure (mean Ϯ SD) with a follow-up of 6.1 Ϯ 4.7 yr. The genotype frequencies for each gene were consistent with Hardy-Weinberg equilibrium, and were similar to those of 100 Caucasian control subjects. We examined two primary outcomes: ( a ) the rate of deterioration of Ccr, and ( b ) the maximal level of proteinuria. We found that patients with the AGT MT ( n ϭ 79) and TT ( n ϭ 29) genotypes had a faster rate of deterioration of Ccr than those with the MM ( n ϭ 60) genotype (i.e., median values, Ϫ 6.6 and Ϫ 6.2 vs.
~bstract 13H]Thymidine (TdR) incorporation by human osteo~arcoma cell line MG-63 was significantly stimulated at as early as 3 h after the addition of either TIMP-1 or TIMP-2 alone. Maximum stimulation was attained at a concentration of either 20 nglml (0.71 nM) TIMP-I or 1.0 ng/ml (46 pM) TIMP-2. ryrosine kinase inhibitors such as genistein, erbstatin, and herbimycin A almost completely inhibited the [3HITdR incorporation stimulated by either of the TIMPs. However, essentially no effect was observed with H-89, H-7, bisindolylmaleimide and K-252a. These inhibition studies suggest a crucial role for t yrosine kinase in the signal transduction of TIMPs. Phospholyrosine-containing proteins were significantly elevated by the treatment with both TIMPs. We also found that either TIMP ~timulated an increase in mitogen-activated protein (MAP) kinase activity, suggesting that MAP kinase plays a role in rlMP-dependent growth signaling.~ey words: Tissue inhibitor of metalloproteinase; Cell ;rowth factor; Tyrosine kinase; Mitogen-activated protein MAP) kinase; MG-63 cell
The imbalance of blood and urine amino acids in renal failure has been studied mostly without chiral separation. Although a few reports have shown the presence of D-serine, an enantiomer of L-serine, in the serum of patients with severe renal failure, it has remained uncertain how serine enantiomers are deranged in the development of renal failure. In the present study, we have monitored serine enantiomers using a two-dimensional HPLC system in the serum and urine of mice after renal ischemia-reperfusion injury (IRI), known as a mouse model of acute kidney injury. In the serum, the level of D-serine gradually increased after renal IRI in parallel with that of creatinine, whereas the L-serine level decreased sharply in the early phase after IRI. The increase of D-serine was suppressed in part by genetic inactivation of a D-serine-degrading enzyme, D-amino acid oxidase (DAO), but not by disruption of its synthetic enzyme, serine racemase, in mice. Renal DAO activity was detected exclusively in proximal tubules, and IRI reduced the number of DAO-positive tubules. On the other hand, in the urine, D-serine was excreted at a rate nearly triple that of L-serine in mice with sham operations, indicating that little D-serine was reabsorbed while most L-serine was reabsorbed in physiological conditions. IRI significantly reduced the ratio of urinary D−/L-serine from 2.82±0.18 to 1.10±0.26 in the early phase and kept the ratio lower than 0.5 thereafter. The urinary D−/L-serine ratio can detect renal ischemia earlier than kidney injury molecule-1 (KIM-1) or neutrophil gelatinase-associated lipocalin (NGAL) in the urine, and more sensitively than creatinine, cystatin C, or the ratio of D−/L-serine in the serum. Our findings provide a novel understanding of the imbalance of amino acids in renal failure and offer a potential new biomarker for an early detection of acute kidney injury.
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