Beta Amyloid 25-35 : Abeta 25-35 :Amyloid Beta Peptide:25-35 : Beta Amyloid Peptides 25-35 : Research Paper of Abeta Peptide 25-35

Beta Amyloid 25-35 : Abeta 25-35 :Amyloid Beta Peptide:25-35 : Beta Amyloid Peptides 25-35 : Research Paper of Abeta Peptide 25-35



Beta amyloid 25-35 peptide Sequence:

One Letter Code:

G S N K G A I I G L M

Three Letter Code:

Gly-Ser-Asn-Lys-Gly-Ala-Ile-Ile-Gly-Leu-Met

Molecular Mass: 1060.3

Research Papers on Beta amyloid 25-35


Title:
Proinflammatory profile of cytokine production by human monocytes and murine microglia stimulated with beta-amyloid[25-35].

Authors:
Meda L, Baron P, Prat E, Scarpini E, Scarlato G, Cassatella MA, Rossi F.


Abstract:
Growing evidence indicates that amyloid (A beta) deposition and phagocyte activation participate in inflammatory reactions in the brain during the course of Alzheimer's disease. To further investigate the effects of A beta-phagocyte interaction, we examined the production of proinflammatory (IL-1beta, IL-6), chemotactic (MIP-1alpha, IP-10) and inhibitory (IL-1Ra, IL-10 and TGFbeta1) cytokines by cultured human monocytes and mouse microglial cells upon stimulation with A beta[25-35]. Northern blot analysis and specific immunoassays demonstrated that A beta[25-35] triggers mRNA expression and release of IL-1beta, IL-1Ra and MIP-1alpha but not of IL-6, IL-10, TGFbeta1 and IP-10 from human monocytes. Similar results were obtained by examining the production of IL-1beta, IL-6 and IL-10 from mouse microglial cells in the same experimental conditions. Taken together, these data indicate that A beta-phagocyte interaction can drive a different response towards cytokine production by monocytes and microglia, with a particular proinflammatory trend, and further support a role for A beta deposition as a triggering factor of inflammatory events in Alzheimer's disease.


Title:
Apoptosis mediated neurotoxicity induced by chronic application of [beta] amyloid fragment 25-35.

Authors:
Forloni, Gianluigi 1; Chiesa, Roberto 1; Smiroldo, Simona 1; Verga, Laura 3; Salmona, Mario 2; Tagliavini, Fabrizio 3; Angeretti, Nadia 1

Abstract:
To investigate whether and how amyloid-[beta] protein (A[beta]) is involved in the neurodegenerative changes characteristic of Alzheimer's disease (AD), primary hippocampal neurones from foetal rat brain were exposed acutely and chronically to micromolar concentrations of a synthetic peptide homologous to residues 25-35 of A[beta] ([beta] 25-35). A single application of this peptide (25-100 [mu]M) was ineffective but when the neuronal culture were exposed to [beta] 25-35 (25-100 [mu]M) repeatedly every two days for ten days, cell survival was dramatically reduced. The structural changes and the DNA fragmentation of cells chronically exposed to the peptide suggested that neuronal death occurred by apoptosis. Furthermore, [beta] 25-35 showed the intrinsic ability to polymerize into amyloid-like fibrils in vitro. These results confirm the potential pathogenic role of A[beta] in AD, and indicate that amyloid fibrils may induce neuronal death through a specific programmed process.

Title:
Estradiol protects against β-amyloid (25–35)-induced toxicity in SK-N-SH human neuroblastoma cells

Authors:
Pattie S. Green, Kelly E. Gridley and James W. Simpkins Corresponding Author Contact Information

Abstract:
Estrogen-replacement therapy has been associated with a reduced incidence of Alzheimer's disease (AD) and improved cognition in several small open clinical trials. We assessed the possibility that estrogens may reduce toxicity of β-amyloid (Aβ) by testing the effects of β-estradiol on the toxicity of the neurotoxic fragment of β-amyloid (Aβ 25–35) in SK-N-SH neuroblastoma cells. Aβ 25–35 caused a dose-dependent death in SK-N-SH cells with a LD50 of 28.9 μM. In cultures simultaneously exposed to 20 μM Aβ and 17 β-estradiol (2 nM), Aβ-induced toxicity was reduced by 83 and 51% in two separate studies. Further studies show that 0.2 nM 17 β-estradiol was as effective as the 2 nM concentration. 17 a-Estradiol (2 nM) conferred neuroprotection equivalent to that of 17 β-estradiol. These data support the hypothesis that estrogens reduce β-amyloid toxicity and this may help explain the beneficial effects of estrogens in AD.


Title:
Beta-amyloid (25-35) peptide and IFN-gamma synergistically induce the production of the chemotactic cytokine MCP-1/JE in monocytes and microglial cells

Authors:
L Meda, S Bernasconi, C Bonaiuto, S Sozzani, D Zhou, L Otvos Jr, A Mantovani, F Rossi and MA Cassatella

Abstract:
The molecular mechanisms involved in the development of senile plaques characteristic of aging and Alzheimer's disease are poorly understood. In this study, we examined whether human monocytes and murine microglial cells stimulated with the active fragment of amyloid beta- protein (Abeta(25-35)) express the monocyte chemotactic protein-1 (MCP- 1)/JE. We show that upon incubation with Abeta(25-35), human monocytes accumulate MCP-1 mRNA and produce significant amounts of MCP-1. The effect of Abeta(25-35) on MCP-1 secretion was neither mimicked by a scrambled analogue nor affected by polymyxin B sulfate, even though the latter almost completely abolished the effect of LPS on MCP-1 expression. Murine microglial cells stimulated with Abeta(25-35) also expressed high levels of JE mRNA (the murine counterpart of MCP-1) and released bioactive chemotactic factors. In addition, we report that IFN- gamma significantly synergizes with Abeta(25-35) either in human monocytes or in murine microglial cells, and that Abeta(25-35) plus/minus IFN-gamma-mediated early induction of MCP-1 mRNA does not require new protein synthesis. Finally, we provide evidence that the Abeta(25-35)- and Abeta plus IFN-gamma-induced production of MCP-1 is, in large part, mediated in an autocrine fashion by endogenous TNF- alpha. Taken together, our findings uncover another novel biologic action of Abeta(25-35) and might help in better understanding the mechanisms underlying mononuclear phagocyte recruitment and activation into amyloid deposits.



Title:
In vivo neurotoxicity of beta-amyloid [β(1–40)] and the β(25–35) fragment

Authors:

N.W. Kowall, A.C. McKee, B.A. Yankner and M.F. Beal

Abstract:
We examined the histological changes produced by injections of beta-amyloid [β(1–40)], and control peptides in rat and monkey cerebral cortex. β(25–35) injections were also studied in rat cortex. Standard immunoperoxidase procedures were used to detect the distribution of tau, MAP2, β(1–40) and ALZ 50 immunoreactivity. All injections produced localized necrosis at the injection site surrounded by a zone of neuronal loss and gliosis. In rat cortex, lesions produced by solubilized β(1–40) and β(25–35) in water were generally larger than those produced by control peptides. Tau and ALZ 50 antibodies labeled neurites and diffusely positive perikarya around β(1–40) injections, whereas MAP2 staining wasreduced, paralleling the distribution of neuronal loss and gliosis. In aged primate cortex, β(1–40) lesion size was dose dependent. Hyalinized, ALZ 50 positive neurons, and abnormal neurites were prominent around the injection site. Although β-amyloid is acutely neurotoxic in both rat and monkey cerebral cortex, neuronal degeneration in the primate more closely resembles that found in AD.


Source: Pub Med