scholarly journals The Blood–Brain Barrier and Its Intercellular Junctions in Age-Related Brain Disorders

2019 ◽  
Vol 20 (21) ◽  
pp. 5472 ◽  
Author(s):  
Laura Costea ◽  
Ádám Mészáros ◽  
Hannelore Bauer ◽  
Hans-Christian Bauer ◽  
Andreas Traweger ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Neurodegenerative Disorders ◽  
Neurological Disorders ◽  
Barrier Function ◽  
Molecular Mechanisms ◽  
Brain Barrier ◽  
Common Denominator ◽  
Blood Brain ◽  
Age Related ◽  
The Brain

With age, our cognitive skills and abilities decline. Maybe starting as an annoyance, this decline can become a major impediment to normal daily life. Recent research shows that the neurodegenerative disorders responsible for age associated cognitive dysfunction are mechanistically linked to the state of the microvasculature in the brain. When the microvasculature does not function properly, ischemia, hypoxia, oxidative stress and related pathologic processes ensue, further damaging vascular and neural function. One of the most important and specialized functions of the brain microvasculature is the blood–brain barrier (BBB), which controls the movement of molecules between blood circulation and the brain parenchyma. In this review, we are focusing on tight junctions (TJs), the multiprotein complexes that play an important role in establishing and maintaining barrier function. After a short introduction of the cell types that modulate barrier function via intercellular communication, we examine how age, age related pathologies and the aging of the immune system affects TJs. Then, we review how the TJs are affected in age associated neurodegenerative disorders: Alzheimer’s disease and Parkinson’s disease. Lastly, we summarize the TJ aspects of Huntington’s disease and schizophrenia. Barrier dysfunction appears to be a common denominator in neurological disorders, warranting detailed research into the molecular mechanisms behind it. Learning the commonalities and differences in the pathomechanism of the BBB injury in different neurological disorders will predictably lead to development of new therapeutics that improve our life as we age.

Brain Drug Delivery: Overcoming the Blood-brain Barrier to Treat Tauopathies

2020 ◽  
Vol 26 (13) ◽  
pp. 1448-1465 ◽  
Author(s):  
Jozef Hanes ◽  
Eva Dobakova ◽  
Petra Majerova
Keyword(s):  
Drug Delivery ◽  
Blood Brain Barrier ◽  
Neurodegenerative Disorders ◽  
Brain Barrier ◽  
Neuronal Function ◽  
Brain Drug Delivery ◽  
Naturally Occurring ◽  
Blood Brain ◽  
Traditional Approaches ◽  
The Brain

Tauopathies are neurodegenerative disorders characterized by the deposition of abnormal tau protein in the brain. The application of potentially effective therapeutics for their successful treatment is hampered by the presence of a naturally occurring brain protection layer called the blood-brain barrier (BBB). BBB represents one of the biggest challenges in the development of therapeutics for central nervous system (CNS) disorders, where sufficient BBB penetration is inevitable. BBB is a heavily restricting barrier regulating the movement of molecules, ions, and cells between the blood and the CNS to secure proper neuronal function and protect the CNS from dangerous substances and processes. Yet, these natural functions possessed by BBB represent a great hurdle for brain drug delivery. This review is concentrated on summarizing the available methods and approaches for effective therapeutics’ delivery through the BBB to treat neurodegenerative disorders with a focus on tauopathies. It describes the traditional approaches but also new nanotechnology strategies emerging with advanced medical techniques. Their limitations and benefits are discussed.

scholarly journals Probable Causes of Alzheimer’s Disease

Sci ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 16
Author(s):  
James David Adams
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Lactic Acid ◽  
Blood Brain Barrier ◽  
Transient Receptor Potential ◽  
Brain Barrier ◽  
Folate Intake ◽  
Blood Brain ◽  
Age Related ◽  
The Brain

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.

Current Updates on the Regulation of Beta-Secretase Movement as a Potential Restorative Focus for Management of Alzheimer's Disease

2019 ◽  
Vol 26 (8) ◽  
pp. 579-587 ◽  
Author(s):  
Syed Sayeed Ahmad ◽  
Mohammad Amjad Kamal
Keyword(s):  
Blood Brain Barrier ◽  
Recent Decade ◽  
High Rate ◽  
Brain Barrier ◽  
Blood Brain ◽  
Age Related ◽  
Beta Secretase ◽  
Influx Transport ◽  
Clearance Receptor ◽  
The Brain

The most recent decade was described by a developing awareness about the seriousness of dementia in the field of age-related people. Among the dementias, Alzheimer's assumes a plentiful role as a result of its amazingly high rate and casualty. A few pharmacological procedures have been attempted yet at the same time now, Alzheimer continues being an untreatable malady. The collection of Aβ in the brain is an early poisonous occasion in the pathogenesis of Alzheimer's disease, which is the most widely recognized type of dementia correlated with plaques and tangles within the brain. However, the mechanism of the intraneuronal direction of BACE1 is poorly understood. AD is caused by mutations in one of the genes that encoding APP, presenilins 1 and 2. Most of the mutations in these genes increase Aβ42 production. Numerous receptors are associated with initiating Aβ transport and clearance. Among them, RAGE is an influx transport receptor that binds soluble Aβ and mediates pathophysiological cellular responses. RAGE additionally intervenes the vehicle of plasma Aβ over the blood-brain barrier. LRP-1 functions as a clearance receptor for Aβ at the blood-brain barrier. The regulation of beta-secretase movement is being explored as a potential restorative focus for treating AD.

scholarly journals Photodynamic Opening of the Blood–Brain Barrier Using Different Photosensitizers in Mice

2019 ◽  
Vol 10 (1) ◽  
pp. 33 ◽  
Author(s):  
Oxana Semyachkina-Glushkovskaya ◽  
Ekaterina Borisova ◽  
Vanya Mantareva ◽  
Ivan Angelov ◽  
Ivelina Eneva ◽  
...  
Keyword(s):  
Tight Junction ◽  
Blood Brain Barrier ◽  
Confocal Imaging ◽  
Brain Barrier ◽  
Zinc Phthalocyanine ◽  
Brain Diseases ◽  
Blood Brain ◽  
Age Related ◽  
Dextran 70 ◽  
The Brain

In a series of previous studies, we demonstrated that the photodynamic therapy (PDT), as a widely used tool for treatment of glioblastoma multiforme (GBM), also site-specifically opens the blood–brain barrier (BBB) in PDT-dose and age-related manner via reversible disorganization of the tight junction machinery. To develop the effective protocol of PDT-opening of the BBB, here we answer the question of what kind of photosensitizer (PS) is the most effective for the BBB opening. We studied the PDT-opening of the BBB in healthy mice using commercial photosensitizers (PSs) such as 5-aminolevulenic acid (5-ALA), aluminum phthalocyanine disulfonate (AlPcS), zinc phthalocyanine (ZnPc) and new synthetized PSs such as galactose functionalized ZnPc (GalZnPc). The spectrofluorimetric assay of Evans Blue albumin complex (EBAC) leakage and 3-D confocal imaging of FITC-dextran 70 kDa (FITCD) extravasation clearly shows a revisable and dose depended PDT-opening of the BBB to EBAC and FITCD associated with a decrease in presence of tight junction (TJ) in the vascular endothelium. The PDT effects on the BBB permeability, TJ expression and the fluorescent signal from the brain tissues are more pronounced in PDT-GalZnPc vs. PDT-5-ALA/AlPcS/ZnPc. These pre-clinical data are the first important informative platform for an optimization of the PDT protocol in the light of new knowledge about PDT-opening of the BBB for drug brain delivery and for the therapy of brain diseases.

scholarly journals Age-Associated Changes in the Immune System and Blood–Brain Barrier Functions

2019 ◽  
Vol 20 (7) ◽  
pp. 1632 ◽  
Author(s):  
Michelle Erickson ◽  
William Banks
Keyword(s):  
Central Nervous System ◽  
Immune System ◽  
Blood Brain Barrier ◽  
Neurological Disorders ◽  
Brain Barrier ◽  
Immune Functions ◽  
Blood Brain ◽  
The Brain ◽  
Brain Barriers

Age is associated with altered immune functions that may affect the brain. Brain barriers, including the blood–brain barrier (BBB) and blood–CSF barrier (BCSFB), are important interfaces for neuroimmune communication, and are affected by aging. In this review, we explore novel mechanisms by which the aging immune system alters central nervous system functions and neuroimmune responses, with a focus on brain barriers. Specific emphasis will be on recent works that have identified novel mechanisms by which BBB/BCSFB functions change with age, interactions of the BBB with age-associated immune factors, and contributions of the BBB to age-associated neurological disorders. Understanding how age alters BBB functions and responses to pathological insults could provide important insight on the role of the BBB in the progression of cognitive decline and neurodegenerative disease.

scholarly journals Blood-Brain Barrier Integrity and Breast Cancer Metastasis to the Brain

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Farheen Arshad ◽  
Lili Wang ◽  
Christopher Sy ◽  
Shalom Avraham ◽  
Hava Karsenty Avraham
Keyword(s):  
Breast Cancer ◽  
Brain Metastasis ◽  
Blood Brain Barrier ◽  
Molecular Mechanisms ◽  
Cancer Metastasis ◽  
Breast Cancer Metastasis ◽  
Brain Barrier ◽  
Treatment Modalities ◽  
Blood Brain ◽  
The Brain

Brain metastasis, an important cause of cancer morbidity and mortality, occurs in at least 30% of patients with breast cancer. A key event of brain metastasis is the migration of cancer cells through the blood-brain barrier (BBB). Although preventing brain metastasis is immensely important for survival, very little is known about the early stage of transmigration and the molecular mechanisms of breast tumor cells penetrating the BBB. The brain endothelium plays an important role in brain metastasis, although the mechanisms are not clear. Brain Microvascular Endothelial Cells (BMECs) are the major cellular constituent of the BBB. BMECs are joined together by intercellular tight junctions (TJs) that are responsible for acquisition of highly selective permeability. Failure of the BBB is a critical event in the development and progression of several diseases that affect the CNS, including brain tumor metastasis development. Here, we have delineated the mechanisms of BBB impairment and breast cancer metastasis to the brain. Understanding the molecular mediators that cause changes in the BBB should lead to better strategies for effective treatment modalities targeted to inhibition of brain tumors.

scholarly journals RADI-03. A strategy to personalize the use of radiation in patients with brain metastasis based on S100A9-mediated resistance

2021 ◽  
Vol 3 (Supplement_3) ◽  
pp. iii18-iii18
Author(s):  
Lauritz Miarka ◽  
Catia Moteiro ◽  
Celine Dalmasso ◽  
Coral Fustero-Torre ◽  
Natalia Yebra ◽  
...  
Keyword(s):  
Brain Metastasis ◽  
Blood Brain Barrier ◽  
Molecular Mechanisms ◽  
Unmet Need ◽  
Brain Barrier ◽  
Breast Adenocarcinoma ◽  
Therapeutic Benefits ◽  
Blood Brain ◽  
The Brain

Abstract Finding effective treatment options for patients with brain metastasis remains an unmet need. Given the limitations imposed by the blood-brain-barrier for systemic approaches, radiotherapy offers a superior ability to access the brain. While clinical practice recently adapted the use of stereotactic radiosurgery (SRS), Whole-Brain-Radiotherapy (WBRT) continuous to be an important treatment option, since many patients present with multifocal lesions or bad performance scores, rendering them ineligible for SRS. Unfortunately, overall survival of patients remains unaffected by radiotherapy. Despite this clinical data, the molecular mechanisms that allow metastatic cells to resist radiotherapy in the brain is unknown. We have applied WBRT to experimental brain metastasis from lung and breast adenocarcinoma and validated their resistance in vivo. An unbiased search to identify potential mediators of resistance identified the S100A9-RAGE-NFkB-JunB pathway. Targeting this pathway genetically reverts the resistance to radiotherapy and increases therapeutic benefits in vivo. In two independent cohorts of brain metastasis from lung and breast adenocarcinoma patients, levels of S100A9 correlate with the response to radiotherapy, offering a novel approach to stratify patients according to their expected benefit. In order to make this biomarker also available for brain metastasis patients receiving palliative WBRT without preceding surgery, we complemented our tumor-specimen based approach with the less invasive detection of S100A9 from liquid biopsies. Here, serum S100A9 also correlated with a worse response to WBRT in brain metastasis patients. Furthermore, we have validated the use of a blood-brain-barrier permeable RAGE inhibitor to restore radio-sensitivity in experimental brain metastasis models in vivo and in patient-derived organotypic cultures of radio-resistant brain metastasis ex vivo. In conclusion, we identified S100A9 as a major mediator of radio-resistance in brain metastasis and offer the molecular framework to personalize radiotherapy by exploiting it as a biomarker and as a therapeutic target, thus maximizing the benefits for the patient.

P02.01 A strategy to personalize the use of radiation in patients with brain metastasis based on S100A9-mediated resistance

2021 ◽  
Vol 23 (Supplement_2) ◽  
pp. ii17-ii17
Author(s):  
L Miarka ◽  
C Monteiro ◽  
C Dalmasso ◽  
N Yebra ◽  
C Fustero-Torre ◽  
...  
Keyword(s):  
Brain Metastasis ◽  
Blood Brain Barrier ◽  
Molecular Mechanisms ◽  
Unmet Need ◽  
Brain Barrier ◽  
Breast Adenocarcinoma ◽  
Therapeutic Benefits ◽  
Blood Brain ◽  
The Brain

Abstract BACKGROUND Finding effective treatment options for patients with brain metastasis remains an unmet need. Given the limitations imposed by the blood-brain-barrier for systemic approaches, radiotherapy offers a superior ability to access the brain. While clinical practice recently adapted the use of stereotactic radiosurgery (SRS), Whole-Brain-Radiotherapy (WBRT) continuous to be an important treatment option, since many patients present with multifocal lesions or bad performance scores, rendering them ineligible for SRS. Unfortunately, overall survival of patients remains unaffected by radiotherapy. Despite this clinical data, the molecular mechanisms that allow metastatic cells to resist radiotherapy in the brain is unknown. MATERIAL AND METHODS We have applied WBRT to experimental brain metastasis from lung and breast adenocarcinoma and validated their resistance in vivo. RESULTS An unbiased search to identify potential mediators of resistance identified the S100A9-RAGE-NFκB-JunB pathway. Targeting this pathway genetically reverts the resistance to radiotherapy and increases therapeutic benefits in vivo. In two independent cohorts of brain metastasis from lung and breast adenocarcinoma patients, levels of S100A9 correlate with the response to radiotherapy, offering a novel approach to stratify patients according to their expected benefit. In order to make this biomarker also available for brain metastasis patients receiving palliative WBRT without preceding surgery, we complemented our tumor-specimen based approach with the less invasive detection of S100A9 from liquid biopsies. Here, serum S100A9 also correlated with a worse response to WBRT in brain metastasis patients. Furthermore, we have validated the use of a blood-brain-barrier permeable RAGE inhibitor to restore radio-sensitivity in experimental brain metastasis models in vivo and in patient-derived organotypic cultures of radio-resistant brain metastasis ex vivo. CONCLUSION We identified S100A9 as a major mediator of radio-resistance in brain metastasis and offer the molecular framework to personalize radiotherapy by exploiting it as a biomarker and as a therapeutic target, thus maximizing the benefits for the patient.

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