Differential Effects of Olanzapine and Haloperidol on MK-801-induced Memory Impairment in Mice.

OBJECTIVE: We investigated the differential effects of the antipsychotic drugs olanzapine and haloperidol on MK-801-induced memory impairment and neurogenesis in mice. METHODS: MK-801 (0.1 mg/kg) was administered 20 minutes prior to behavioral testing over 9 days. Beginning on the sixth day of MK-801 treatment, either olanzapine (0.05 mg/kg) or haloperidol (0.05 mg/kg) was administered 40 minutes prior to MK-801 for the final 4 days. Spatial memory performance was measured using a Morris water maze (MWM) test for 9 days (four trials/day). Immunohistochemistry with bromodeoxyuridine (BrdU) was used to identify newborn cells labeled in tissue sections from the dentate gyrus of the hippocampus. RESULTS: MK-801 administration over 9 days significantly impaired memory performance in the MWM test compared to untreated controls (p＜0.05) and these deficits were blocked by treatment with olanzapine (p＜0.05) but not haloperidol. The administration of MK-801 also resulted in a decrease in the number of BrdU-labeled cells in the dentate gyrus (28.6%; p＜0.01), which was prevented by treatment with olanzapine (p＜0.05) but not haloperidol. CONCLUSION: These results suggest that olanzapine has a protective effect against cognitive impairments induced by MK-801 in mice via the stimulating effects of neurogenesis.

SUMO1 promotes Aß production via the modulation of autophagy.

Autophagy is one of the main mechanisms in the pathophysiology of neurodegenerative disease. The accumulation of autophagic vacuoles (AVs) in affected neurons is responsible for amyloid-ß (Aß) production. Previously, we reported that SUMO1 (small ubiquitin-like modifier 1) increases Aß levels. In this study, we explored the mechanisms underlying this. We investigated whether AV formation is necessary for Aß production by SUMO1. Overexpression of SUMO1 increased autophagic activation, inducing the formation of LC3-II-positive AVs in neuroglioma H4 cells. Consistently, autophagic activation was decreased by the depletion of SUMO1 with small hairpin RNA (shRNA) in H4 cells. The SUMO1-mediated increase in Aß was reduced by the autophagy inhibitors (3-methyladenine or wortmannin) or genetic inhibitors (siRNA targeting ATG5, ATG7, ATG12, or HIF1A), respectively. Accumulation of SUMO1, ATG12, and LC3 was seen in amyloid precursor protein transgenic mice. Our results suggest that SUMO1 accelerates the accumulation of AVs and promotes Aß production, which is a key mechanism for understanding the AV-mediated pathophysiology of Alzheimer disease.

NDP52 associates with phosphorylated tau in brains of an Alzheimer disease mouse model.

We previously showed that NDP52 (also known as calcoco2) plays a role as an autophagic receptor for phosphorylated tau facilitating its clearance via autophagy. Here, we examined the expression and association of NDP52 with autophagy-regulated gene (ATG) proteins including LC3, as well as phosphorylated tau and amyloid-beta (Aß) in brains of an AD mouse model. NDP52 was expressed not only in neurons, but also in microglia and astrocytes. NDP52 co-localized with ATGs and phosphorylated tau as expected since it functions as an autophagy receptor for phosphorylated tau in brain. Compared to wild-type mice, the number of autophagic vesicles (AVs) containing NDP52 in both cortex and hippocampal regions was significantly greater in AD model mice. Moreover, the protein levels of NDP52 and phosphorylated tau together with LC3-II were also significantly increased in AD model mice, reflecting autophagy impairment in the AD mouse model. By contrast, a significant change in p62/SQSTM1 level was not observed in this AD mouse model. NDP52 was also associated with intracellular Aß, but not with the extracellular Aß of amyloid plaques. We conclude that NDP52 is a key autophagy receptor for phosphorylated tau in brain. Further our data provide clear evidence for autophagy impairment in brains of AD mouse model, and thus strategies that result in enhancement of autophagic flux in AD are likely to be beneficial.

Aging-related Changes in Mouse Serum Glycerophospholipid Profiles.

OBJECTIVES: Metabolic dysfunction is a common hallmark of the aging process and aging-related pathogenesis. Blood metabolites have been used as biomarkers for many diseases, including cancers, complex chronic diseases, and neurodegenerative diseases. METHODS: In order to identify aging-related biomarkers from blood metabolites, we investigated the specific metabolite profiles of mouse sera from 4-month-old and 21-month-old mice by using a combined flow injection analysis-tandem mass spectrometry and liquid chromatography-tandem mass spectrometry. RESULTS: Among the 156 metabolites detected, serum levels of nine individual metabolites were found to vary with aging. Specifically, lysophosphatidylcholine (LPC) acyl (a) C24:0 levels in aged mice were decreased compared to that in young mice, whereas phosphatidylcholine (PC) acyl-alkyl (ae) C38:4, PC ae C40:4, and PC ae C42:1 levels were increased. Three classes of metabolites (amino acids, LPCs, and PCs) differed in intraclass correlation patterns of the individual metabolites between sera from young and aged mice. Additionally, the ratio of LPC a C24:0 to PC ae C38:4 was decreased in the aged mice, whereas the ratio of PC ae C40:4 to LPC a C24:0 was increased, supporting the aging-related metabolic changes of glycerophospholipids. CONCLUSION: The ratios of the individual metabolites PC and LPC could serve as potential biomarkers for aging and aging-related diseases.

SUMO1 modulates Aß generation via BACE1 accumulation.

Accumulation of disease-related proteins is a characteristic event observed in the pathogenesis of neurodegenerative diseases. ß-secretase (BACE)-1, which initiates generation of ß-amyloid (Aß), is increased in the Alzheimer's diseased brain. However, the mechanisms of BACE1 accumulation in Alzheimer's disease are largely unknown. In this report, we found that small ubiquitin-like modifier (SUMO)-1 interacts with the dileucine motif of BACE1 and regulates the level of BACE1 protein. This was proved by the coimmunoprecipitation, and gain or loss of function experiments. Altering 3 SUMO isoforms affects BACE1 protein levels, and consequently results in altered amyloid precursor protein processing and Aß generation. BACE1 levels were increased in response to Aß or apoptosis, but not in cells lacking SUMO1. Aß increased SUMO1 protein levels in rat cortical neurons. Moreover, SUMO1 immunoreactivity was increased in the amyloid precursor protein transgenic mice. Furthermore, the C-terminus fragments of BACE1 containing dileucine motif reduced Aß generation by SUMO1 overexpression. Our study indicates SUMO1 is not only a novel and potent regulator of BACE1 accumulation and Aß generation but also a potential therapeutic target for Alzheimer's disease.

Supine position endoscopic retrograde cholangiopancreatography in a patient with situs ambiguous with polysplenia.

A 58-year-old woman complained of painless jaundice. The serology showed total bilirubin 10.6 mg/dL with direct bilirubin of 7.0 mg/dL. Abdominal computed tomography (CT) scan disclosed an abnormal arrangement of the abdominal viscera and dilation of the biliary tree. A nearly 1.4 cm-sized periampullary mass was seen. These findings are compatible with situs ambiguous with polysplenia and were suggestive of a periampullary tumor. Due to her unusual anatomical features, the patient underwent an endoscopic retrograde cholangiopancreatography (ERCP) in the supine position instead of in the conventional prone position. ERCP showed that the common bile duct (CBD) diameter was increased to 20 mm. Microscopic findings of the biopsy specimen of papillary mass were compatible with an adenocarcinoma of the ampulla of Vater. The clinical stage was stage IA (T1N0M0). Eight days later, a papillectomy was carried out by endoscopic snare resection. Six months later, follow-up studies, including ERCP, abdominal CT and 18-fluorodeoxyglucose positron emission tomography ((18) -FDG PET)-CT scan, showed no evidence of recurrence. Although the success rate of supine position ERCP may be influenced by the extent of the intestinal malrotation and the position of the duodenum, we conclude that supine position ERCP can be carried out effectively in a patient with situs anomaly.

Differences in hippocampal CREB phosphorylation in trace fear conditioning of two inbred mouse strains.

The effects of genetic background on fear trace conditioning were evaluated in relation to phosphorylated levels of cAMP response element-binding protein (CREB) in the hippocampus using two different inbred strains of mice, C57BL/6 and DBA/2. The male mice received a trace fear conditioning protocol and unpaired control groups were included to assess nonassociative effects on test performance. Both C57BL/6 and DBA/2 mice with paired training displayed higher freezing responses during testing than those with unpaired training, respectively. The C57BL/6 mice with paired training also displayed higher freezing responses to the tone-CS during testing than the DBA/2 mice with paired training. Because much evidence implicates the hippocampus as an important neural substrate for trace fear conditioning, the engagement of the hippocampus was examined after testing by measuring levels of CREB and phosphorylated CREB (pCREB). The results revealed that hippocampal CREB levels in both strains of mice were not significantly altered according to the type of training (unpaired vs. paired). However, the hippocampal pCREB levels were significantly higher in the paired training group than the unpaired control group in C57BL/6 mice, but not in DBA/2 mice. These findings indicate that hippocampal pCREB is closely tied to this form of associative conditioning only in C57BL/6 mice and that different neural substrates may support trace conditioning in C57BL/6 and DBA/2 strains.

[A case of colonic cryptococcosis].

We experienced a rare case of colonic cryptococcosis in an apparently immunocompetent individual. A 27-year- old woman admitted our hospital for intermittent melena. Initial abdominal CT scan revealed a mass lesion obstructing most of the lumen in ascending colon. Colonoscopy showed huge ulcerofungating mass in proximal ascending colon. Colonoscopic biopsy was performed and pathologic diagnosis was made as colonic cryptococcosis with positive PAS stain. Laboratory test evaluating immune status and bone marrow examination was normal. The patient was treated with intravenous amphotericin B for four weeks and six months of oral fluconazole afterwards. Follow-up abdominal CT scan and colonoscopy were taken at four weeks and seven months after the beginning of treatment. On completion of intravenous amphotericin B treatment, the mass lesion was decreased in abdominal CT and colonoscopy. After seven months, abdominal CT and colonoscopy showed near-complete resolution of the colonic lesion so the treatment ended. Cryptococcosis in a healthy individual is a rare disease and there have been only several sporadic case reports on pulmonary or central nervous system involvement. Hence, we report a case of colonic cryptococcosis in an apparently immunocompetent individual.