Review Article
Year: 2017 | Month: Aug | Volume: 7 | Issue: 8 | Pages: 386-395
Neuroprotective Effects of High Density Lipoproteins (APOE) and Neurodegenerative Disorders Related to Apoe-Hdl
Demeke Ashencho1, Yekoye Abebe2, Daniel Seifu3
1MR, St. Paul Hospital Millennium Medical College, Department of Physiology, Addis Ababa, Ethiopia
2Professor, 3Doctor,
Department of Medical Physiology, College of Health Sciences, University of Addis Ababa, Addis Ababa, Ethiopia
Corresponding Author: Demeke Ashencho
ABSTRACT
There are a number of potential mechanisms through which HDL could act to protect neural function. Apolipoproteins E is the most abundant apolipoproteins in the brain. ApoE-HDL and cholesterol are synthesized mainly by de novo synthesis in astrocytes. Three major functions of astrocyte-derived ApoE-containing lipoproteins includes transfer of phospholipids and cholesterol via ATP-binding cassette (ABC) transporters such as ABCA1 and ABCG1,interaction with the LDLR super family of proteins located on the surface of neurons to facilitate axonal growth and neuronal survival and interaction with the LRP1-dependent cellular uptake pathway in the deposition of amyloid plaques. Cholesterol is a very important membrane lipid to keep function and survival of neurons in the brain. The brain contains about 20% of whole body cholesterol. Brain cholesterol is involved in axonal elongation, dendrite differentiation, synapse development and synapse formation, long-term potentiation, Learning and memory Neuroprotective effects of ApoE-HDL in the brain includes suppression of Aβ production by decreasing cellular cholesterol, can directly bind excess Aβ and thereby inhibit cholesterol oligomerisation, remove Aβ that accumulates in the vessel wall during the course of VD, decrease oxidative stress and thereby indirectly decrease Aβ production, can act on astrocytes to attenuate a local inflammatory reaction, accelerates maturation of synapses and maintain of synaptic plasticity. Disturbances in cholesterol homeostasis have been associated to the onset and the development of several neurological disorders such as AD, NPC and HD disease.
Key words: ApoE-HDL, Neuroprotection, Brain cholesterol, synapse development, synaptic plasticity, Neurodegenerative disorders