scholarly journals Alternative pathways for production of β-amyloid peptides of Alzheimer's disease

2008 ◽  
Vol 389 (8) ◽  
Author(s):  
Vivian Hook ◽  
Israel Schechter ◽  
Hans-Ulrich Demuth ◽  
Gregory Hook
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Posttranslational Modifications ◽  
Cathepsin B ◽  
Cathepsin D ◽  
General Meeting ◽  
Glutaminyl Cyclase ◽  
Alternative Pathways ◽  
Β Amyloid ◽  
Bace 1

Abstract This highlight article describes three Alzheimer's disease (AD) studies presented at the 5th General Meeting of the International Proteolysis Society that address enzymatic mechanisms for producing neurotoxic β-amyloid (Aβ) peptides. One group described the poor kinetics of BACE 1 for cleaving the wild-type (WT) β-secretase site of APP found in most AD patients. They showed that cathepsin D displays BACE 1-like specificity and cathepsin D is 280-fold more abundant in human brain than BACE 1. Nevertheless, as BACE 1 and cathepsin D show poor activity towards the WT β-secretase site, they suggested continuing the search for additional β-secretase(s). The second group reported cathepsin B as an alternative β-secretase possessing excellent kinetic efficiency and specificity for the WT β-secretase site. Significantly, inhibitors of cathepsin B improved memory, with reduced amyloid plaques and decreased Aβ(40/42) in brains of AD animal models expressing amyloid precursor protein containing the WT β-secretase site. The third group addressed isoaspartate and pyroglutamate (pGlu) posttranslational modifications of Aβ. Results showed that cathepsin B, but not BACE 1, efficiently cleaves the WT β-secretase isoaspartate site. Furthermore, cyclization of N-terminal Glu by glutaminyl cyclase generates highly amyloidogenic pGluAβ(3–40/42). These presentations suggest cathepsin B and glutaminyl cyclase as potential new AD therapeutic targets.

Alternative pathways for production of β-amyloid peptides of Alzheimer's disease

2008 ◽  
Vol 0 (ja) ◽  
pp. 080808070126964-37 ◽  
Author(s):  
Vivian Hook ◽  
Israel Schechter ◽  
Hans-Ulrich Demuth ◽  
Gregory Hook
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Peptides ◽  
Alternative Pathways ◽  
Β Amyloid

scholarly journals Pharmacogenetic features of cathepsin B inhibitors that improve memory deficit and reduce β-amyloid related to Alzheimer's disease

2010 ◽  
Vol 391 (8) ◽  
Author(s):  
Vivian Hook ◽  
Gregory Hook ◽  
Mark Kindy
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Mouse Models ◽  
Cathepsin B ◽  
Memory Deficit ◽  
Mutant Site ◽  
Amyloid Aβ ◽  
Β Amyloid ◽  
The Brain ◽  
Aβ Production

Abstract Beta-amyloid (Aβ) in the brain is a major factor involved in Alzheimer's disease (AD) that results in severe memory deficit. Our recent studies demonstrate pharmacogenetic differences in the effects of inhibitors of cathepsin B to improve memory and reduce Aβ in different mouse models of AD. The inhibitors improve memory and reduce brain Aβ in mice expressing the wild-type (WT) β-secretase site of human APP, expressed in most AD patients. However, these inhibitors have no effect in mice expressing the rare Swedish (Swe) mutant amyloid precursor protein (APP). Knockout of the cathepsin B decreased brain Aβ in mice expressing WT APP, validating cathepsin B as the target. The specificity of cathepsin B to cleave the WT β-secretase site, but not the Swe mutant site, of APP for Aβ production explains the distinct inhibitor responses in the different AD mouse models. In contrast to cathepsin B, the BACE1 β-secretase prefers to cleave the Swe mutant site. Discussion of BACE1 data in the field indicate that they do not preclude cathepsin B as also being a β-secretase. Cathepsin B and BACE1 could participate jointly as β-secretases. Significantly, the majority of AD patients express WT APP and, therefore, inhibitors of cathepsin B represent candidate drugs for AD.

scholarly journals BACE-1 is expressed in the blood–brain barrier endothelium and is upregulated in a murine model of Alzheimer’s disease

2015 ◽  
Vol 36 (7) ◽  
pp. 1281-1294 ◽  
Author(s):  
Kavi Devraj ◽  
Slobodan Poznanovic ◽  
Christoph Spahn ◽  
Gerhard Schwall ◽  
Patrick N Harter ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Endothelial Cells ◽  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Blood Brain ◽  
Mouse Brain Endothelial Cells ◽  
Primary Mouse ◽  
Β Amyloid ◽  
Bace 1

Endothelial cells of the blood–brain barrier form a structural and functional barrier maintaining brain homeostasis via paracellular tight junctions and specific transporters such as P-glycoprotein. The blood–brain barrier is responsible for negligible bioavailability of many neuroprotective drugs. In Alzheimer’s disease, current treatment approaches include inhibitors of BACE-1 (β-site of amyloid precursor protein cleaving enzyme), a proteinase generating neurotoxic β-amyloid. It is known that BACE-1 is highly expressed in endosomes and membranes of neurons and glia. We now provide evidence that BACE-1 is expressed in blood–brain barrier endothelial cells of human, mouse, and bovine origin. We further show its predominant membrane localization by 3D- dSTORM super-resolution microscopy, and by biochemical fractionation that further shows an abluminal distribution of BACE-1 in brain microvessels. We confirm its functionality in processing APP in primary mouse brain endothelial cells. In an Alzheimer’s disease mouse model we show that BACE-1 is upregulated at the blood–brain barrier compared to healthy controls. We therefore suggest a critical role for BACE-1 at the blood–brain barrier in β-amyloid generation and in vascular aspects of Alzheimer’s disease, particularly in the development of cerebral amyloid angiopathy.

scholarly journals BACE-1 and γ-Secretase as Therapeutic Targets for Alzheimer’s Disease

2019 ◽  
Vol 12 (1) ◽  
pp. 41 ◽  
Author(s):  
Miguel Maia ◽  
Emília Sousa
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Health Concern ◽  
Pharmacological Agents ◽  
Drug Candidates ◽  
Structure Activity ◽  
Β Amyloid ◽  
Cns Penetration ◽  
Disease Modifying Agents ◽  
Bace 1

Alzheimer’s disease (AD) is a growing global health concern with a massive impact on affected individuals and society. Despite the considerable advances achieved in the understanding of AD pathogenesis, researchers have not been successful in fully identifying the mechanisms involved in disease progression. The amyloid hypothesis, currently the prevalent theory for AD, defends the deposition of β-amyloid protein (Aβ) aggregates as the trigger of a series of events leading to neuronal dysfunction and dementia. Hence, several research and development (R&D) programs have been led by the pharmaceutical industry in an effort to discover effective and safety anti-amyloid agents as disease modifying agents for AD. Among 19 drug candidates identified in the AD pipeline, nine have their mechanism of action centered in the activity of β or γ-secretase proteases, covering almost 50% of the identified agents. These drug candidates must fulfill the general rigid prerequisites for a drug aimed for central nervous system (CNS) penetration and selectivity toward different aspartyl proteases. This review presents the classes of γ-secretase and beta-site APP cleaving enzyme 1 (BACE-1) inhibitors under development, highlighting their structure-activity relationship, among other physical-chemistry aspects important for the successful development of new anti-AD pharmacological agents.

Аnticholinesterase and antioxidant activity of new binary conjugates of (с)-carbolines

2019 ◽  
Vol 484 (1) ◽  
pp. 104-108
Author(s):  
G. F. Makhaeva ◽  
E. F. Shevtsova ◽  
N. P. Boltneva ◽  
N. V. Kovaleva ◽  
E. V. Rudakova ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Antioxidant Activity ◽  
Anticholinesterase Activity ◽  
Amyloid Aggregation ◽  
Varying Length ◽  
Β Amyloid ◽  
New Compounds

This study presents the synthesis of binary tetrohydro-γ-carbolines with ditriazol spacers of varying length, which exhibit anticholinesterase and antioxidant activity, as compared to the original Dimebon prototype. Anticholinesterase activity suggests the potential ability of the new compounds to block β-amyloid aggregation induced by anticholinesterase, making them promising candidates for further research preparations for the treatment of Alzheimer's disease. Particular attention should be paid to the conjugate with an intertriazol hexamethylene spacer, which can be regarded as the leading compound in this series.

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