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1.
Int J Rheum Dis ; 27(1): e15034, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38287545

ABSTRACT

OBJECTIVE: This study aimed to determine whether there are associations between laughter, disease activity, frailty, and depression in rheumatoid arthritis (RA) patients. METHODS: A total of 240 patients were included in this prospective cohort study on frailty in RA patients between March 2021 and June 2022. Patients were divided into the following four groups according to the frequency of laughter: "almost every day," "1-5 days per week," "1-3 days per month," and "never or almost never." Patient characteristics were compared among the four groups by analysis of variance. Factors associated with laughter were identified by multivariable logistic analysis. RESULTS: The mean 28-joint Disease Activity Score using CRP was 1.91, with 70.7% of patients in remission and 12.6% in low disease activity. For the "almost every day" (42.5% of patients), "1-5 days per week" (40.0%), "1-3 days per month" (11.3%), and "never or almost never" (6.3%) groups, scores of the Kihon Checklist (KCL) for assessing frailty status were 3.5, 4.6, 7.3, and 8.1 (p < .001), respectively, and scores of the Beck Depression Inventory (BDI-II) were 8.4, 10.7, 15.1, and 16.5 (p < .001), respectively. Multivariable analysis revealed that KCL (OR: 0.81, 95% CI: 0.73-0.90) and BDI-II (OR: 0.91, 95% CI: 0.86-0.95) scores were independently associated with the frequency of laughter. CONCLUSION: Frailty and depression were associated with laughter in RA patients with controlled disease activity. Interventions aimed at not only disease activity control but also frailty prevention may lead to a life filled with laughter.


Subject(s)
Arthritis, Rheumatoid , Frailty , Laughter , Humans , Depression/diagnosis , Depression/epidemiology , Depression/etiology , Frailty/diagnosis , Frailty/epidemiology , Prospective Studies , Arthritis, Rheumatoid/diagnosis , Arthritis, Rheumatoid/epidemiology
2.
J Hazard Mater ; 465: 133469, 2024 Mar 05.
Article in English | MEDLINE | ID: mdl-38219585

ABSTRACT

The bulky phenolic compound tetrabromobisphenol A (TBBPA) is a brominated flame retardant used in a wide range of products; however, it diffuses into the environment, and has been reported to have toxic effects. Although it is well-known that white-rot fungi degrade TBBPA through ligninolytic enzymes, no other metabolic enzymes have yet been identified, and the toxicity of the reaction products and their risks have not yet been examined. We found that the white-rot fungus Phanerochaete sordida YK-624 converted TBBPA to TBBPA-O-ß-D-glucopyranoside when grown under non-ligninolytic-enzyme-producing conditions. The metabolite showed less cytotoxicity and mitochondrial toxicity than TBBPA in neuroblastoma cells. From molecular biological and genetic engineering experiments, two P. sordida glycosyltransferases (PsGT1c and PsGT1e) that catalyze the glycosylation of TBBPA were newly identified; these enzymes showed dramatically different glycosylation activities for TBBPA and bisphenol A. The results of computational analyses indicated that the difference in substrate specificity is likely due to differences in the structure of the substrate-binding pocket. It appears that P. sordida YK-624 takes up TBBPA, and reduces its cytotoxicity via these glycosyltransferases.


Subject(s)
Phanerochaete , Polybrominated Biphenyls , Biotransformation , Phanerochaete/metabolism , Polybrominated Biphenyls/metabolism , Glycosyltransferases/metabolism
3.
J Org Chem ; 86(3): 2602-2620, 2021 02 05.
Article in English | MEDLINE | ID: mdl-33492133

ABSTRACT

The first total syntheses of hericenones C-H and "putative 3-hydroxyhericenone F" were achieved. Highlights of the synthesis include the straightforward construction of the resorcinol core and geranyl side chain, assembly of the natural product skeleton by sequential O-geranylation and a clay/zeolite-mediated O → C rearrangement reaction, and a biomimetic cyclization to form a variety of bicyclic natural hericenones and their congeners. The structure of the "putative 3-hydroxyhericenone F" was revised as the 5-exo cyclization product (named: hericenone Z) of epoxyhericenone C through in-depth analyses of the cyclization modes in addition to NMR spectroscopic studies. To gain insights into the biological functions of geranyl-resorcinols in Hericium erinaceus, potential neuroprotective effects against endoplasmic reticulum (ER) stress-dependent cell death were evaluated systematically to clarify a fundamental structure-activity relationship. Among the compounds assayed, the linoleate-containing hericenone analogue, i.e., the regioisomer of hericene D, was found to possess the most potent neuroprotective effect against tunicamycin and thapsigargin-induced ER stress-dependent cell death.


Subject(s)
Biological Products , Neuroprotective Agents , Biological Products/pharmacology , Hericium , Neuroprotective Agents/pharmacology
4.
Int J Rheum Dis ; 22(2): 207-213, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30168274

ABSTRACT

AIM: This study aimed to determine the influence of methotrexate (MTX) on gastrointestinal (GI) symptoms in patients with rheumatoid arthritis (RA). METHODS: This cross-sectional study examined 529 consecutive patients with RA receiving oral MTX in our department between April 1 and September 30, 2017. GI symptoms were evaluated by the Gastrointestinal Symptom Rating Scale (GSRS); a score of ≥2 was considered "symptomatic." Prevalence of GI symptoms was compared between patients receiving ≤8 mg/wk (low-dose) vs >8 mg/wk (high-dose) of MTX. RESULTS: Of our study population, 313 (59%) received low-dose MTX at a median (interquartile range) dose of 6 (6-8) mg/wk, whereas 216 (41%) received high-dose MTX at a median dose of 12 (10-12) mg/wk. Relative to the low-dose MTX group, the high-dose MTX group exhibited a higher prevalence of reflux (32% vs 24%, P = 0.043) and abdominal pain (28% vs 18%, P = 0.007). There was no significant group-dependent difference in the prevalence of indigestion, diarrhea or constipation. Multivariate logistic regression analysis revealed that high-dose MTX (>8 mg/wk) was independently associated with reflux (odds ratio [OR]: 1.62, 95% confidence interval [CI]: 1.07-2.43) and abdominal pain (OR: 1.60, 95% CI: 1.04-2.43), and that the ORs for reflux and abdominal pain among those receiving high-dose MTX (>8 mg/wk) were similar to those using nonsteroidal anti-inflammatory drugs. CONCLUSION: High-dose MTX is independently associated with the prevalence of upper GI symptoms in Japanese patients with RA.


Subject(s)
Antirheumatic Agents/administration & dosage , Antirheumatic Agents/adverse effects , Arthritis, Rheumatoid/drug therapy , Gastrointestinal Diseases/chemically induced , Methotrexate/administration & dosage , Methotrexate/adverse effects , Administration, Oral , Aged , Arthritis, Rheumatoid/diagnosis , Arthritis, Rheumatoid/epidemiology , Cross-Sectional Studies , Female , Gastrointestinal Diseases/diagnosis , Gastrointestinal Diseases/epidemiology , Humans , Japan/epidemiology , Male , Middle Aged , Prevalence , Quality of Life , Risk Factors , Time Factors , Treatment Outcome
5.
Heliyon ; 3(11): e00462, 2017 Nov.
Article in English | MEDLINE | ID: mdl-29264419

ABSTRACT

The genus Cordyceps and its specific ingredient, cordycepin, have attracted much attention for multiple health benefits and expectations for lifespan extension. We analyzed whether Cordyceps militaris (CM), which contains large amounts of cordycepin, can extend the survival of Dahl salt-sensitive rats, whose survival was reduced to ∼3 months via a high-salt diet. The survival of these life-shortened rats was extended significantly when supplemented with CM, possibly due to a minimization of the effects of stroke. Next, we analyzed the effect of CM on hypertension-sensitive organs, the central nervous systems (CNS), heart, kidney and liver of these rats. We attempted to ascertain how the organs were improved by CM, and we paid particular attention to mitochondria and autophagy functions. The following results were from CM-treated rats in comparison with control rats. Microscopically, CNS neurons, cardiomyocytes, glomerular podocytes, renal epithelial cells, and hepatocytes all were improved. However, immunoblot and immunohistochemical analysis showed that the expressions of mitochondria-related proteins, ATP synthase ß subunit, SIRT3 and SOD2, and autophagy-related proteins, LC3-II/LC3-I ratio and cathepsin D all were reduced significantly in the CNS neurons, but increased significantly in the cells of the other three organs, although p62 was decreased in its expression in all the organs tested. Activity of Akt and mTOR was enhanced but that of AMPK was reduced in the CNS, while such kinase activity was completely the opposite in the other organs. Together, the influence of CM may differ between mitochondria and autophagy functioned between the two organ groups, as mitochondria and autophagy seemed to be repressed and promoted, respectively, in the CNS, while both mitochondria and autophagy were activated in the others. This could possibly be related to the steady or improved cellular activity in both the organs, which might result in the life extension of these rats.

6.
J Hazard Mater ; 321: 586-590, 2017 Jan 05.
Article in English | MEDLINE | ID: mdl-27694022

ABSTRACT

Clothianidin (CLO) is a member of the neonicotinoid pesticides, which have been widely used worldwide over the last two decades. However, its toxicity for bees and neurological toxicity for humans are urgent problems. Here, the degradation of CLO by the white-rot fungus Phanerochaete sordida was examined in nitrogen-limited liquid medium. After incubation for 20days at 30°C, 37% of CLO was degraded in the cultures. High-resolution ESI-MS and NMR analyses of the culture supernatant identified N-(2-chlorothiazol-5-yl-methyl)-N'-methylurea (TZMU) as a metabolite of CLO degradation. The addition of cytochrome P450 inhibitors to the culture medium markedly reduced the degradation of CLO by P. sordida. And manganese peroxidase, a major ligninolytic enzyme secreted by this fungus, were not carried out CLO degradation. The effects of CLO and TZMU on the viability of the neuronal cell line Neuro2a demonstrated that P. sordida effectively degrades CLO into a metabolite that lacks neurotoxicity.


Subject(s)
Biodegradation, Environmental , Guanidines/chemistry , Insecticides/chemistry , Neonicotinoids/chemistry , Phanerochaete/metabolism , Thiazoles/chemistry , Cell Line , Culture Media , Cytochrome P-450 Enzyme Inhibitors/pharmacology , Guanidines/toxicity , Humans , Insecticides/toxicity , Magnetic Resonance Spectroscopy , Neonicotinoids/toxicity , Neurotoxicity Syndromes/pathology , Phanerochaete/drug effects , Spectrometry, Mass, Electrospray Ionization , Thiazoles/toxicity
7.
Neurotoxicol Teratol ; 48: 33-9, 2015.
Article in English | MEDLINE | ID: mdl-25619426

ABSTRACT

Phytanic acid is a branched fatty acid that is a metabolic intermediate of chlorophyll. In this study, the effects of phytanic acid on Histone deacetylase (Hdac) activity were examined in an in vitro enzyme assay and in neuronal Neuro2a cells. Several fatty acids have been shown to be Hdac inhibitors, but phytanic acid enhanced the enzyme activity in vitro. In Neuro2a cells, phytanic acid significantly reduced histone acetylation and induced cell death, which was inhibited by an Hdac inhibitor, sodium butyrate. Theophylline, a common Hdac activator, had a similar effect on Neuro2a cell viability, and this effect was also inhibited by sodium butyrate. Phytanic acid decreased the level of intracellular active mitochondria, while butyrate increased this level. The cytotoxic effect of phytanic acid was also abolished by a caspase-9 inhibitor. Apicidin, a Hdac2- and 3-specific inhibitor, reduced the cellular toxicity, which suggests that the toxicity of phytanic acid depends on activation of the Hdac2 and 3 subtypes. Overall, these results show that phytanic acid induces mitochondrial abnormality and cell death via activation of Hdac2, 3 in Neuro2a cells. This effect of Hdac activation by phytanic acid may produce neuronal damage in Refsum disease and other peroxisomal disorders, which is caused by accumulation of phytanic acid.


Subject(s)
Apoptosis/drug effects , Histone Deacetylases/metabolism , Mitochondria/drug effects , Neurons/drug effects , Phytanic Acid/toxicity , Animals , Cell Line , Cell Line, Tumor , Mice , Mitochondria/enzymology , Neurons/enzymology
8.
Food Sci Nutr ; 2(5): 565-70, 2014 Sep.
Article in English | MEDLINE | ID: mdl-25473514

ABSTRACT

Propolis is a resinous product produced by honey bees and is known to have antitumor functions. On the other hand, histone deacetylase (Hdac) inhibitors have recently attracted attention for their antitumor effects. In this study, we examined whether Brazilian green propolis has an Hdac inhibitory activity and its contribution on antitumor effects. By in vitro Hdac activity assay, Brazilian propolis extract (BPE) significantly inhibited the enzyme activity. Actually, BPE treatment increased the intracellular histone acetylation in Neuro2a cells. Regarding antitumor effect in Neuro2a cells, BPE treatment significantly decreased cell viability. An Hdac activator theophylline significantly attenuated the effect. Then, we analyzed whether the decreasing effect on cell number was caused by cell death or growth retardation. By live/dead cell staining, BPE treatment significantly increased the dead cell number. By cell cycle analysis, BPE treatment retarded cell cycle at the M-phase. Both of these cellular effects were suppressed by addition of theophylline. These data indicate that BPE induced both cell death and growth retardation via Hdac inhibitory activity. We demonstrated that Brazilian propolis bears regulatory functions on histone acetylation via Hdac inhibition, and the effect contributes antitumor functions. Our data suggest that intake of Brazilian propolis shows preventing effects against cancer.

9.
J Nat Prod ; 77(7): 1729-33, 2014 Jul 25.
Article in English | MEDLINE | ID: mdl-24988471

ABSTRACT

Two novel compounds, 1 and 7, along with six known compounds (2-6 and 8), were isolated from the edible mushroom Mycoleptodonoides aitchisonii (bunaharitake in Japanese). The structures of the new compounds were determined by the interpretation of spectroscopic data. Compounds 1-4 and 6-8 showed protective activity against endoplasmic reticulum stress-dependent cell death.


Subject(s)
Agaricales/chemistry , Endoplasmic Reticulum Stress , Furans/isolation & purification , Furans/pharmacology , Pentanes/isolation & purification , Pentanes/pharmacology , Animals , Cell Death/drug effects , Crystallography, X-Ray , Fruiting Bodies, Fungal/chemistry , Furans/chemistry , Japan , Molecular Conformation , Molecular Structure , Pentanes/chemistry
10.
Br J Pharmacol ; 170(4): 822-34, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23869584

ABSTRACT

BACKGROUND AND PURPOSE: 4-Phenylbutyric acid (4-PBA) is a chemical chaperone that eliminates the accumulation of unfolded proteins in the endoplasmic reticulum (ER). However, its chaperoning ability is often weak and unable to attenuate the unfolded protein response (UPR) in vitro or in vivo. To develop more potent chemical chaperones, we synthesized six analogues of 4-PBA and evaluated their pharmacological actions on the UPR. EXPERIMENTAL APPROACH: NRK-52E cells were treated with ER stress inducers (tunicamycin or thapsigargin) in the presence of each of the 4-PBA analogues; the suppressive effects of these analogues on the UPR were assessed using selective indicators for individual UPR pathways. KEY RESULTS: 2-POAA-OMe, 2-POAA-NO2 and 2-NOAA, but not others, suppressed the induction of ER stress markers GRP78 and CHOP. This suppressive effect was more potent than that of 4-PBA. Of the three major UPR branches, the IRE1 and ATF6 pathways were markedly blocked by these compounds, as indicated by suppression of XBP1 splicing, inhibition of UPRE and ERSE activation, and inhibition of JNK phosphorylation. Unexpectedly, however, these agents did not inhibit phosphorylation of PERK and eIF2α triggered by ER stress. These compounds dose-dependently inhibited the early activation of NF-κB in ER stress-exposed cells. 2-POAA-OMe and 2-POAA-NO2 also inhibited ER stress-induced phosphorylation of Akt. CONCLUSION AND IMPLICATIONS: The 4-PBA analogues 2-POAA-OMe, 2-POAA-NO2 and 2-NOAA strongly inhibited activation of the IRE1 and ATF6 pathways and downstream pathogenic targets, including NF-κB and Akt, in ER stress-exposed cells. These compounds may be useful for therapeutic intervention in ER stress-related pathological conditions.


Subject(s)
Endoplasmic Reticulum Stress/drug effects , LIM Domain Proteins/antagonists & inhibitors , Membrane Proteins/antagonists & inhibitors , Microfilament Proteins/antagonists & inhibitors , Phenylbutyrates/pharmacology , Protein Kinase Inhibitors/pharmacology , Protein Serine-Threonine Kinases/antagonists & inhibitors , Signal Transduction/drug effects , Unfolded Protein Response/drug effects , Animals , Cell Line , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Dose-Response Relationship, Drug , Eukaryotic Initiation Factor-2/metabolism , Heat-Shock Proteins/metabolism , JNK Mitogen-Activated Protein Kinases/metabolism , LIM Domain Proteins/metabolism , Membrane Proteins/metabolism , Microfilament Proteins/metabolism , NF-kappa B/genetics , NF-kappa B/metabolism , Phosphorylation , Protein Serine-Threonine Kinases/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Rats , Regulatory Factor X Transcription Factors , Transcription Factor CHOP/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism , Transfection , X-Box Binding Protein 1 , eIF-2 Kinase/metabolism
12.
Bioorg Med Chem Lett ; 22(13): 4246-8, 2012 Jul 01.
Article in English | MEDLINE | ID: mdl-22672800

ABSTRACT

Makomotindoline (1) was isolated from Makomotake, Zizania latifolia infected with Ustilago esculenta. The structure was determined by the interpretation of spectroscopic data and synthesis. Makomotindoline (1), its l-Glc isomer (2) and its aglycon (3) were synthesized and their effects on rat glioma cells showed adverse effects on the cell growth.


Subject(s)
Glycosides/chemistry , Indoles/chemistry , Poaceae/chemistry , Ustilago/physiology , Animals , Cell Proliferation/drug effects , Glycosides/isolation & purification , Glycosides/pharmacology , Indoles/isolation & purification , Indoles/pharmacology , Magnetic Resonance Spectroscopy , Molecular Conformation , Poaceae/microbiology , Rats , Stereoisomerism
13.
J Biosci Bioeng ; 114(4): 466-71, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22664345

ABSTRACT

Endoplasmic reticulum stress commonly causes neuronal damage in a lot of neurodegenerative diseases. In this study, we examined neuroprotective effect of bovine milk phospholipid fraction (mPL) on mouse neuroblastoma Neuro2a cells from endoplasmic reticulum (ER) stress induced cell death. Neuro2a cells were induced cell death by ER stressor tunicamycin (TM) or thapsigargin (TG), and studied whether mPL could attenuate the toxicity. By preincubation with mPL, the cell viabilities were significantly increased in TM or TG treated cells, and caspase-12 activated cells induced by TM or TG treatment were significantly decreased. Protein kinase C inhibitor GF109203x significantly reduced the protective effect on TM induced cell death, and autophagy inhibitor 3-methyladenine reduced the protective effect on TM or TG induced cell death. Moreover, preincubation with mPL significantly stimulated autophagosomes formation observed by dansylcadaverine staining. Our data suggest that mPL will be applicable to prevent neurodegenerative diseases caused by ER stress.


Subject(s)
Autophagy , Endoplasmic Reticulum Stress , Milk/chemistry , Neurons/cytology , Neuroprotective Agents/pharmacology , Phospholipids/pharmacology , Protein Kinase C/metabolism , Animals , Caspase 12/metabolism , Cell Death/drug effects , Cell Line, Tumor , Mice , Milk/metabolism , Neurodegenerative Diseases/chemically induced , Neurodegenerative Diseases/drug therapy , Neurons/drug effects , Neurons/metabolism , Signal Transduction/drug effects , Thapsigargin , Tunicamycin
16.
Org Lett ; 12(21): 5012-5, 2010 Nov 05.
Article in English | MEDLINE | ID: mdl-20936815

ABSTRACT

Five fatty acid amides, termitomycamides A to E (1 to 5), were isolated from the giant edible mushroom Termitomyces titanicus. The structures of 1-5 were determined by the interpretation of spectral data and/or synthesis. Compounds 2 and 5 showed protective activity against endoplasmic reticulum stress-dependent cell death.


Subject(s)
Endoplasmic Reticulum/drug effects , Fatty Acids, Unsaturated/chemistry , Stress, Physiological/drug effects , Termitomyces/chemistry , Animals , Cell Death/drug effects , Cell Line, Tumor , Fatty Acids, Unsaturated/isolation & purification , Fatty Acids, Unsaturated/pharmacology , Mice , Molecular Structure
17.
J Pharmacol Sci ; 113(1): 3-8, 2010.
Article in English | MEDLINE | ID: mdl-20424390

ABSTRACT

Epigenetics is a mechanism that regulates gene expression not depending on the underlying DNA sequence, but on the chemical modifications of DNA and histone proteins. Defects in the factors involved in epigenetic regulation cause congenital neurodevelopmental diseases, and thus, epigenetic regulation is essential for normal brain development. Besides these intrinsic defects, it is becoming increasingly apparent that extrinsic factors, such as insufficient nutrition, psychiatric drugs, and mental stress, also alter epigenetic regulation. Therefore, environmental factors may lead to "acquired" neurodevelopmental disorders through the failure of epigenetic regulation. Epigenetics is a biological key to understand the gene-environment interactions in neurodevelopmental disorders. As the mechanism is reversible, its comprehensive understanding will result in the development of new therapies for these disorders.


Subject(s)
Brain/growth & development , Drug Delivery Systems/methods , Environment , Genes , Nervous System Diseases/genetics , Animals , Brain/metabolism , DNA Methylation/drug effects , Epigenesis, Genetic , Genetic Predisposition to Disease , Humans , Models, Genetic , Nervous System Diseases/drug therapy , Nervous System Diseases/metabolism
18.
J Biosci Bioeng ; 108(3): 248-51, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19664561

ABSTRACT

When central nervous system is injured, reactive astrocytes form glial scar which prevents neuronal regeneration. We examined the effects of concanavalin A (ConA) in primary astrocytes, and found preferential apoptotic effect of ConA in migrating reactive astrocytes. Thus, ConA may be applicable for enhancing neuronal regeneration by preventing glial scar.


Subject(s)
Apoptosis/drug effects , Astrocytes/cytology , Concanavalin A/chemistry , Animals , Animals, Newborn , Cell Survival , Cells, Cultured , Concanavalin A/pharmacology , Glycoproteins/chemistry , Mannose/chemistry , Neuroglia/pathology , Neurons/cytology , Neurons/metabolism , Rats , Rats, Wistar , Regeneration , Tetrazolium Salts/pharmacology , Thiazoles/pharmacology
19.
Biosci Biotechnol Biochem ; 73(8): 1908-10, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19661683

ABSTRACT

Four compounds were isolated from scrap cultivation beds of the mushroom, Hericium erinaceum. Compounds 1-4 were identified as methyl 4-hydroxy-3-(3-methylbutanoyl) benzoate, 2-chloro-1,3-dimethoxy-5-methylbenzene, methyl 4-chloro-3,5-dimethoxybenzoate, and 4-chloro-3,5-dimethoxybenzaldehyde by an interpretation of the NMR and MS data, respectively. This is the first reported isolation of 1 from a natural source. All the compounds showed protective activity against endoplasmic reticulum stress-dependent cell death.


Subject(s)
Basidiomycota/chemistry , Basidiomycota/growth & development , Endoplasmic Reticulum/drug effects , Stress, Physiological/drug effects , Benzaldehydes/chemistry , Benzaldehydes/isolation & purification , Benzaldehydes/pharmacology , Benzene/chemistry , Benzene/isolation & purification , Benzene/pharmacology , Benzoates/chemistry , Benzoates/isolation & purification , Benzoates/pharmacology , Cell Death/drug effects , Cell Line, Tumor , Endoplasmic Reticulum/pathology , Humans , Magnetic Resonance Spectroscopy , Mass Spectrometry
20.
Neurotoxicology ; 30(1): 144-50, 2009 Jan.
Article in English | MEDLINE | ID: mdl-19028522

ABSTRACT

N-glycosylation is crucial for proper folding of most of the proteins in the endoplasmic reticulum (ER). The N-glycans in the ER are mainly constructed of mannose. In this study, we examined whether inhibition of mannose trimming in the ER affects the susceptibility of PC-12 cells to ER stress. Pretreatment with 100 microM alpha-mannosidase inhibitor 1-deoxymannojirimycin (DMJ) in PC-12 cells significantly attenuated the cytotoxicity by ER stressors tunicamycin (TM), thapsigargin (TG), and amyloid beta1-42 (Abeta1-42), and reduced caspase-3 activation by TM and TG. Pretreatment with DMJ also protected primary cultured mouse cortical neurons from Abeta1-42 toxicity. With regard to the effect of DMJ pretreatment on ER stress signaling in PC-12 cells, DMJ attenuated TM- and TG-induced CHOP expression and TG stimulated JNK phosphorylation, which is associated with ER stress dependent cell death. Next, we examined the effect of mannose oligosaccharides, which have similar structures to N-glycans in the ER, on amyloidogenesis of Abeta1-42 that causes ER stress dependent neuronal cell death. Mannopentaose (M5) and Man9GlcNAc2 (M9) oligosaccharides significantly inhibited the amyloidogenesis of Abeta1-42. Our data suggests that inhibition of N-glycan processing in the ER attenuates ER stress-induced cell death by increasing high-mannose type oligosaccharides that reduce protein aggregation, such as amyloidogenesis.


Subject(s)
Endoplasmic Reticulum/metabolism , Neurons/metabolism , Stress, Physiological/drug effects , alpha-Mannosidase/antagonists & inhibitors , 1-Deoxynojirimycin/pharmacology , Amyloid/antagonists & inhibitors , Amyloid/biosynthesis , Animals , Cell Death/drug effects , Cell Line, Transformed , Cells, Cultured , Cricetinae , Enzyme Inhibitors/pharmacology , Mannose/analogs & derivatives , Mice , Rats
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