Beta-amyloid peptides induces neuronal apoptosis via a mechanism independent of unfolded protein responses

Yu, Man-Shan; Suen, Ka-Chun; Kwok, Nga-Sze; So, Kwok-Fai; Hugon, Jacques; Chang, Raymond Chuen‐Chung

doi:10.1007/s10495-006-5540-1

Cited by 51 publications

(37 citation statements)

References 73 publications

(162 reference statements)

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“…Preliminary studies suggested that cultured neurons pre-treated with Fructus lycii extract could attenuate Aß-induced apoptosis via the [25][26][27][28][29][30][31][32][33][34][35] peptide. Neurons were pretreated with LBP-III (10, 100 and 500 μg/ml) for 1 h, followed by a 4-h exposure to 25 μM of Aß [25][26][27][28][29][30][31][32][33][34][35] . Immunoblotting was performed to determine the level of phosphorylated PKR (Thr446/451), total PKR and ß-actin (used as the internal control).…”

Section: Discussionmentioning

confidence: 99%

“…Primary neuronal cultures were prepared from day 17 embryonic Sprague-Drawley rats (Laboratory Animal Unit, The University of Hong Kong) according to our methods (6,19,20,(23)(24)(25)(26)(27)(28). Briefly, after removal of the meninges the cortices were minced and plated onto poly-L-lysine-(25 μg/ml) coated 6-well plates at 2x10 6 cells/well.…”

Section: Preparation Of Lbp and Separation Of Lbp-iiimentioning

confidence: 99%

“…Neurons were maintained in a 5% CO 2 incubator at 37˚C prior to treatments. Cultured neurons at day 7 in vitro were pre-treated with LBP at various concentrations for 1 h and followed by incubation with Aß [25][26][27][28][29][30][31][32][33][34][35] (25 μM, Sigma) for 24 h.…”

Section: Preparation Of Lbp and Separation Of Lbp-iiimentioning

confidence: 99%

“…After treatments, cellular proteins were extracted in ice-cold lysis buffer as described previously (6,19,20,(23)(24)(25)(26)(27)(28). Seventy micrograms of protein per lane were applied to SDS-PAGE (10%) and then were transferred onto a PVDF membrane (Bio-Rad).…”

Section: Preparation Of Lbp and Separation Of Lbp-iiimentioning

confidence: 99%

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Characterization of the effects of anti-aging medicine Fructus lycii on β-amyloid peptide neurotoxicity

Lai²,

Ho³

et al. 2007

Int J Mol Med

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Abstract. Alzheimer's disease (AD) is an age-related neurodegenerative disease. There are increasing lines of evidence showing that the molecular signaling pathways in aged cells are altered so that cells are susceptible to injury. We and other laboratories have demonstrated the significant involvement of double-stranded RNA-dependent protein kinase (PKR) in ß-amyloid (Aß) peptide neurotoxicity and in AD. Fructus lycii (the fruit of Lycium barbarum) has long been used in oriental medicine as an anti-aging agent. Our previous studies demonstrated that the aqueous extract isolated from L. barbarum exhibited significant protection on cultured neurons against harmful chemical toxins such as Aß and dithiothreitol. We also showed that the polysaccharidecontaining extract (LBP) from L. barbarum exhibited neuroprotective effects in the retina against ocular hypertension in a laser-induced glaucoma animal model. In this study, we aimed to investigate whether LBP can elicit neuroprotection to neurons stressed by Aß peptides. Furthermore, we planned to isolate and identify the neuroprotective agent from LBP using chromatographic methods. Our results showed that pretreatment of LBP effectively protected neurons against Aß-induced apoptosis by reducing the activity of both caspase-3 and -2, but not caspase-8 and -9. A new arabinogalactan-protein (LBP-III) was isolated from LBP and attenuated Aß peptide-activated caspase-3-like activity.LBP-III markedly reduced the phosphorylation of PKR triggered by Aß peptide. Since the phosphorylation state of PKR increased with age, reduction of its phosphorylation triggered by Aß peptide may implicate that LBP-III from Fructus lycii is a potential neuroprotective agent in AD. As herbal medicine has received increasing attention for the treatment of AD, our study will open a window for the development of a neuroprotective agent for anti-aging from Chinese medicine.

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Section: Discussionmentioning

confidence: 99%

Section: Preparation Of Lbp and Separation Of Lbp-iiimentioning

confidence: 99%

Section: Preparation Of Lbp and Separation Of Lbp-iiimentioning

confidence: 99%

Section: Preparation Of Lbp and Separation Of Lbp-iiimentioning

confidence: 99%

See 2 more Smart Citations

Characterization of the effects of anti-aging medicine Fructus lycii on β-amyloid peptide neurotoxicity

Lai²,

Ho³

et al. 2007

Int J Mol Med

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“…Amyloid precursor peptides including the toxic Aß 1-42 fragment have previously been shown to induce apoptosis in a variety of cells such as neurons [1][2][3][4][5][6], pancreatic islet cells [7,8], endothelial cells [9] and neutrophils [10]. Mechanisms implicated in amyloid 176 induced apoptosis include Ca 2+ entry [10], calpain activation [5], oxidative stress [1,2,4] and ceramide formation [3].…”

Section: Introductionmentioning

confidence: 99%

Amyloid Induced Suicidal Erythrocyte Death

Nicolay

Gatz

Liebig

et al. 2007

Cell Physiol Biochem

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Amyloid peptides are known to induce apoptosis in a wide variety of cells. Erythrocytes may similarly undergo suicidal death or eryptosis, which is characterized by scrambling of the cell membrane with subsequent exposure of phosphatidylserine (PS) at the cell surface. Eryptosis is triggered by increase of cytosolic Ca²⁺ activity and by activation of acid sphingomyelinase with subsequent formation of ceramide. Triggers of eryptosis include energy depletion and isosmotic cell shrinkage (replacement of extracellular Cl^- by impermeable gluconate for 24 h). The present study explored whether amyloid peptide Aβ _1-42 could trigger eryptosis and to possibly identify underlying mechanisms. Erythrocytes from healthy volunteers were exposed to amyloid and PS-exposure (annexin V binding), cell volume (forward scatter), cytosolic Ca²⁺ activity (Fluo3 fluorescence) and ceramide formation (anti-ceramide antibody) were determined by FACS analysis. Exposure of erythrocytes to the amyloid peptide Aβ _1-42 (? 0.5 µM) for 24 h significantly triggered annexin V binding, an effect mimicked to a lesser extent by the amyloid peptide Aβ _1-40 (1 µM). Aβ _1-42 (? 1.0 µM) further significantly decreased forward scatter of erythrocytes. The effect of Aβ _1-42 (? 0.5 µM) on erythrocyte annexin V binding was paralleled by formation of ceramide but not by significant increase of cytosolic Ca²⁺ activity. The presence of Aβ _1-42 further significantly enhanced the eryptosis following Cl^- depletion but not of glucose depletion for 24 hours. The present observations disclose a novel action of Aβ _1-42, which may well contribute to the pathophysiological effects of amyloid peptides, such as vascular complications in Alzheimer''s disease.

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Up‐regulation of crystallins is involved in the neuroprotective effect of wolfberry on survival of retinal ganglion cells in rat ocular hypertension model

Chiu

Zhou

Yeung

et al. 2010

J of Cellular Biochemistry

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Wolfberry (fruit of Lycium barbarum Linn) has been known for balancing 'Yin' and 'Yang' in the body, nourishing the liver and kidney, improving visual acuity for more than 2,500 years in oriental countries. The active components in wolfberry include L. barbarum polysaccharide (LBP), zeaxanthine, betaine, cerebroside and trace amounts of zinc, iron, and copper. Each of them confers distinct beneficial effects and together they help to explain widespread use of wolfberry in the eastern world. Earlier study reported the neuroprotective effects of LBP on retinal ganglion cell (RGC) in an experimental model of glaucoma and the underlying in vivo cellular mechanisms of LBP neuroprotection deserve further exploration. In this study, we adopted proteomics, functional genomics, to evaluate pharmacological effects of LBP on the neuronal survival pathways. Among the significantly changed proteins induced by LBP feeding on ocular hypertension (OH) retinas, only proteins in crystallin family were focused in this study. The proteomic results were further confirmed using the Western blotting of the retinas and immunohistochemical staining of the retinal sections. We demonstrated that neuroprotective effect of-wolfberry extract-LBP on the survival of RGCs may be mediated via direct up-regulation of neuronal survival signal betaB2-crystallin.

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Beta-amyloid peptides induces neuronal apoptosis via a mechanism independent of unfolded protein responses

Cited by 51 publications

References 73 publications

Characterization of the effects of anti-aging medicine Fructus lycii on β-amyloid peptide neurotoxicity

Characterization of the effects of anti-aging medicine Fructus lycii on β-amyloid peptide neurotoxicity

Amyloid Induced Suicidal Erythrocyte Death

Up‐regulation of crystallins is involved in the neuroprotective effect of wolfberry on survival of retinal ganglion cells in rat ocular hypertension model

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