ApoE deficiency leads to a progressive age-dependent blood-brain barrier leakage

2007 ◽  
Vol 292 (4) ◽  
pp. C1256-C1262 ◽  
Author(s):  
Ali Hafezi-Moghadam ◽  
Kennard L. Thomas ◽  
Denisa D. Wagner

Previously, we reported a defect in the blood-brain barrier (BBB) of apolipoprotein E-deficient (apoE−/−) mice ( 24 ). Here, we investigate BBB permeability in wild-type (WT) and apoE−/− mice as a function of age. Both WT and apoE−/− mice showed significantly increased cortical BBB leakage with age. However, in apoE−/− mice, the leakage increased at a 3.7× higher rate compared with WT mice. Surprisingly, the cerebellum showed significantly more leakage than other brain regions across age, while there was no difference between the two hemispheres. To determine the contribution of tissue- vs. blood-borne apoE to vascular permeability, we generated chimeric mice by bone marrow transplantation and measured their BBB leakage. These experiments suggest that both blood- and tissue-derived apoE are equally important for BBB function. In sum, we find an age-dependent defect in the BBB that is exacerbated in apoE−/− mice. Since vascular defects are found in patients with age-related neurodegenerative diseases, such as Alzheimer's, age-related BBB leakage could underlie these defects and may thus be an important contributor to the cumulative neuronal damage of these diseases.

1996 ◽  
Vol 15 (3) ◽  
pp. 231-236 ◽  
Author(s):  
PS Widdowson ◽  
MJ Farnworth ◽  
MG Simpson ◽  
EA Lock

Experiments were performed to determine the extent of paraquat entry into the brain of neonatal and elderly rats, as compared with adult rats, which may be dependent on the efficacy of the blood-brain barrier. A single, median lethal dose (20 mg/kg s.c.) of paraquat containing [14C]paraquat was administered to neonatal (10 day old), adult (3 month old) and elderly (18 month old) rats. In contrast to the adult and elderly rats where paraquat levels fell over the 24 h post-dosing period to negligible levels, paraquat concentrations in neonatal brains did not decrease with time between 0.5 and 24 h following dosing. The distribution of [14C]paraquat was measured in selective brain regions using quantitative autoradiogra phy in all three age groups of rats, 30 min and 24 h following dosing. Autoradiography demonstrated that brain paraquat distributions were similar in the rat age groups. Most of the paraquat was confined to regions outside the blood-brain barrier and to brain regions that lack a complete blood-brain barrier e.g. dorsal hypotha lamus, area postrema and the anterior olfactory bulb. Between 0.5 h and 24 h following dosing, paraquat concentrations in deeper brain structures, some distance away from the sites of entry, began to slowly increase in all the rat age groups. By 24 h following dosing, a majority of brain regions examined using quantitative autoradiogra phy revealed significantly higher paraquat concentrations in neonatal brains as compared to brain regions of adult and elderly rats. Despite increased paraquat entry into neonatal brain, we could find no evidence for paraquat- induced neuronal cell damage following a detailed histopathological examination of perfused-fixed brains. In conclusion, impaired blood-brain barrier integrity in neonatal brain thus permitting more paraquat to enter than in adult brain, did not result in neuronal damage.


2010 ◽  
Vol 30 (8) ◽  
pp. 1477-1486 ◽  
Author(s):  
Furat Raslan ◽  
Tobias Schwarz ◽  
Sven G Meuth ◽  
Madeleine Austinat ◽  
Michael Bader ◽  
...  

Kinins are proinflammatory and vasoactive peptides that are released during tissue damage and may contribute to neuronal degeneration, inflammation, and edema formation after brain injury by acting on discrete bradykinin receptors, B1R and B2R. We studied the expression of B1R and B2R and the effect of their inhibition on lesion size, blood–brain barrier (BBB) disruption, and inflammatory processes after a focal cryolesion of the right parietal cortex in mice. B1R and B2R gene transcripts were significantly induced in the lesioned hemispheres of wild-type mice ( P<0.05). The volume of the cortical lesions and neuronal damage at 24 h after injury in B1R −/− mice were significantly smaller than in wild-type controls (2.5±2.6 versus 11.5±3.9 mm3, P<0.001). Treatment with the B1R antagonist R-715 1 h after lesion induction likewise reduced lesion volume in wild-type mice (2.6±1.4 versus 12.2±6.1 mm3, P<0.001). This was accompanied by a remarkable reduction of BBB disruption and tissue inflammation. In contrast, genetic deletion or pharmacological inhibition of B2R had no significant impact on lesion formation or the development of brain edema. We conclude that B1R inhibition may offer a novel therapeutic strategy after acute brain injuries.


Sci ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 16
Author(s):  
James David Adams

A three-part mechanism is proposed for the induction of Alzheimer’s disease: (1) decreased blood lactic acid; (2) increased blood ceramide and adipokines; (3) decreased blood folic acid. The age-related nature of these mechanisms comes from age-associated decreased muscle mass, increased visceral fat and changes in diet. This mechanism also explains why many people do not develop Alzheimer’s disease. Simple changes in lifestyle and diet can prevent Alzheimer’s disease. Alzheimer’s disease is caused by a cascade of events that culminates in damage to the blood–brain barrier and damage to neurons. The blood–brain barrier keeps toxic molecules out of the brain and retains essential molecules in the brain. Lactic acid is a nutrient to the brain and is produced by exercise. Damage to endothelial cells and pericytes by inadequate lactic acid leads to blood–brain barrier damage and brain damage. Inadequate folate intake and oxidative stress induced by activation of transient receptor potential cation channels and endothelial nitric oxide synthase damage the blood–brain barrier. NAD depletion due to inadequate intake of nicotinamide and alterations in the kynurenine pathway damages neurons. Changes in microRNA levels may be the terminal events that cause neuronal death leading to Alzheimer’s disease. A new mechanism of Alzheimer’s disease induction is presented involving lactic acid, ceramide, IL-1β, tumor necrosis factor α, folate, nicotinamide, kynurenine metabolites and microRNA.


Author(s):  
Federica Sommonte ◽  
Ilaria Arduino ◽  
Giuseppe Francesco Racaniello ◽  
Antonio Lopalco ◽  
Angela Assunta Lopedota ◽  
...  

1953 ◽  
Vol 98 (5) ◽  
pp. 509-520 ◽  
Author(s):  
F. Stephen Vogel

Kernicteric pigment was extracted by means of chloroform from the brains of 3 infants. Solutions of it gave a positive diazo reaction, and, as determined electrophotometrically, gave maximum absorption of light having a wavelength of 425 mµ, being identical in these properties with chloroform solutions of crystalline mesobilirubin. Experimental kernicterus was regularly induced by injecting crystalline mesobilirubin intracerebrally in newborn kittens, the pigment staining the cerebral tissues a bright canary-yellow and being deposited abundantly in the nerve cells, as microscopic examinations showed, although these latter were otherwise intact. Bilirubin, likewise injected intracerebrally in newborn kittens, had no such effects. The possibility is discussed that the blood-brain barrier is altered in some infants with hyperbilirubinemia in such a way that bilirubin crosses it and is then reduced within the brain to mesobilirubin thus giving rise to the cerebral pigmentation of kernicterus. The fact that the pigment itself does not seem to damage the neurons, as the present studies show, makes it necessary to seek some other cause for the neuronal damage that is sometimes seen, in association with the pigmentation, in the naturally occurring disease.


Author(s):  
Masaki Ueno ◽  
Hironobu Naiki ◽  
Ichiro Akiguchi ◽  
Toshio Kawamata ◽  
Yasuhisa Fujibayashi ◽  
...  

Neurosurgery ◽  
1984 ◽  
Vol 15 (3) ◽  
pp. 362-366 ◽  
Author(s):  
Edward A. Neuwelt ◽  
Suellen A. Hill ◽  
Eugene P. Frenkel

Abstract Chemotherapeutic drug delivery can be enhanced by administering drugs into the internal carotid or vertebral artery circulation after osmotic opening of the blood-brain barrier (BBB). As evidence of the clinical implications of this technique, radiographic documentation of central nervous system (CNS) tumor regression was observed in three patients concurrent with the development of new tumor nodule(s) in portions of the brain distant from the region of osmotic blood-brain barrier opening. These three patients, one with metastatic carcinoma of the breast, one with glioblastoma, and one with primary CNS lymphoma, highlight the importance of drug delivery to CNS malignancies.


2021 ◽  
Vol 22 (18) ◽  
pp. 10045
Author(s):  
Phuong Thao Do ◽  
Chung-Che Wu ◽  
Yung-Hsiao Chiang ◽  
Chaur-Jong Hu ◽  
Kai-Yun Chen

Ischemic stroke is the leading cause of mortality and long-term disability worldwide. Disruption of the blood–brain barrier (BBB) is a prominent pathophysiological mechanism, responsible for a series of subsequent inflammatory cascades that exacerbate the damage to brain tissue. However, the benefit of recanalization is limited in most patients because of the narrow therapeutic time window. Recently, mesenchymal stem cells (MSCs) have been assessed as excellent candidates for cell-based therapy in cerebral ischemia, including neuroinflammatory alleviation, angiogenesis and neurogenesis promotion through their paracrine actions. In addition, accumulating evidence on how MSC therapy preserves BBB integrity after stroke may open up novel therapeutic targets for treating cerebrovascular diseases. In this review, we focus on the molecular mechanisms of MSC-based therapy in the ischemia-induced prevention of BBB compromise. Currently, therapeutic effects of MSCs for stroke are primarily based on the fundamental pathogenesis of BBB breakdown, such as attenuating leukocyte infiltration, matrix metalloproteinase (MMP) regulation, antioxidant, anti-inflammation, stabilizing morphology and crosstalk between cellular components of the BBB. We also discuss prospective studies to improve the effectiveness of MSC therapy through enhanced migration into defined brain regions of stem cells. Targeted therapy is a promising new direction and is being prioritized for extensive research.


2021 ◽  
Vol 16 (1) ◽  
pp. 845-855
Author(s):  
Huaxu Yu ◽  
Bin He ◽  
Xu Han ◽  
Ting Yan

Abstract Rufinamide (RUF) is a structurally unique anti-epileptic drug, but its protective mechanism against brain injury remains unclear. In the present study, we validated how the RUF protected mice with kainic acid (KA)-induced neuronal damage. To achieve that, a mouse epilepsy model was established by KA intraperitoneal injection. After Nissl staining, although there was a significant reduction in Nissl bodies in mice treated with KA, 40, 80, and 120 mg/kg, RUF significantly reduced KA-induced neuronal damage, in a dose-dependent manner. Among them, 120 mg/kg RUF was most pronounced. Immunohistochemistry (IHC) and western blot analysis showed that RUF inhibited the IBA-1 overexpression caused by KA to block microglia cell overactivation. Further, RUF treatment partially reversed neuroinflammatory cytokine (IL-1β, TNFα, HMGB1, and NLRP3) overexpression in mRNA and protein levels in KA mice. Moreover, although KA stimulation inhibited the expression of tight junctions, RUF treatment significantly upregulated expression of tight junction proteins (occludin and claudin 5) in both mRNA and protein levels in the brain tissues of KA mice. RUF inhibited the overactivation of microglia, suppressed the neuroinflammatory response, and reduced the destruction of blood–brain barrier, thereby alleviating the excitatory nerve damage of the KA-mice.


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