scholarly journals MicroRNAs in the Blood-Brain Barrier in Hypoxic-Ischemic Brain Injury

2020 ◽  
Vol 18 (12) ◽  
pp. 1180-1186
Author(s):  
Guofang Shen ◽  
Qingyi Ma

Hypoxic-ischemic (HI) brain injury is a leading cause of acute mortality and chronic disability in newborns. Current evidence shows that cerebral microvascular response and compromised blood-brain barrier (BBB) integrity occur rapidly and could primarily be responsible for the brain injury observed in many infants with HI brain injury. MicroRNAs (miRNAs) are a type of highly conserved non-coding RNAs (ncRNAs), which consist of 21-25 nucleotides in length and usually lead to suppression of target gene expression. Growing evidence has revealed that brainenriched miRNAs act as versatile regulators of BBB dysfunctions in various neurological disorders including neonatal HI brain injury. In the present review, we summarize the current findings regarding the role of miRNAs in BBB impairment after hypoxia/ischemia brain injury. Specifically, we focus on the recent progress of miRNAs in the pathologies of neonatal HI brain injury. These findings can not only deepen our understanding of the role of miRNAs in BBB impairment in HI brain injury, but also provide insight into the development of new therapeutic strategies for preservation of BBB integrity under pathological conditions.

2020 ◽  
Author(s):  
Axel Erik Andersson ◽  
Carina Mallard ◽  
Carl Joakim Ek

Abstract BackgroundNeonatal hypoxia-ischemia often leads to lifelong disabilities with limited treatments currently available. The brain vasculature is an important factor in many neonatal brain pathologies but there is a lack of diagnostic tools to evaluate the brain vascular health of neonates in a clinical setting. Measurement of blood-brain barrier tight-junction proteins have shown promise as biomarkers for brain injury in the adult. Here we tested the biomarker potential of tight-junctions in the context of neonatal brain injury.MethodsThe levels of TJ-proteins (occluding, claudin-5, and zonula occludens-1) in both blood plasma and cerebrospinal fluid (CSF) as well as blood-brain barrier function were measured in a clinically relevant hypoxia/ischemia model in neonatal rats.ResultsTemporally acute elevated levels of occludin and claudin-5 could be measured in blood and CSF after hypoxia/ischemia with males generally having higher levels than females. The levels of claudin-5 in CSF correlated with the severity of the brain injury at 24h post- hypoxia/ischemia. Simultaneously, we detected early increase in blood-brain barrier-permeability at 6 and 24h after hypoxia/ischemia.ConclusionsLevels of circulating claudin-5 and occludin are increased after hypoxic/ischemic brain injuries and blood-brain barrier-impairment and have promise as early biomarkers for cerebral vascular health and as a tool for risk assessment of neonatal brain injuries.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
E. Axel Andersson ◽  
Carina Mallard ◽  
C. Joakim Ek

Abstract Background Neonatal encephalopathy often leads to lifelong disabilities with limited treatments currently available. The brain vasculature is an important factor in many neonatal neurological disorders but there is a lack of diagnostic tools to evaluate the brain vascular dysfunction of neonates in the clinical setting. Measurement of blood–brain barrier tight-junction (TJ) proteins have shown promise as biomarkers for brain injury in the adult. Here we tested the biomarker potential of tight-junctions in the context of neonatal brain injury. Methods The levels of TJ-proteins (occluding, claudin-5, and zonula occludens protein 1) in both blood plasma and cerebrospinal fluid (CSF) as well as blood–brain barrier function via 14C-sucrose (342 Da) and Evans blue extravasation were measured in a hypoxia/ischemia brain-injury model in neonatal rats. Results Time-dependent changes of occludin and claudin-5 levels could be measured in blood and CSF after hypoxia/ischemia with males generally having higher levels than females. The levels of claudin-5 in CSF correlated with the severity of the brain injury at 24 h post- hypoxia/ischemia. Simultaneously, we detected early increase in blood–brain barrier-permeability at 6 and 24 h after hypoxia/ischemia. Conclusions Levels of circulating claudin-5 and occludin are increased after hypoxic/ischemic brain injuries and blood–brain barrier-impairment and have promise as early biomarkers for cerebral vascular dysfunction and as a tool for risk assessment of neonatal brain injuries.


2021 ◽  
Author(s):  
Axel Erik Andersson ◽  
Carina Mallard ◽  
Carl Joakim Ek

Abstract Background Neonatal encephalopathy often leads to lifelong disabilities with limited treatments currently available. The brain vasculature is an important factor in many neonatal neurological disorders but there is a lack of diagnostic tools to evaluate the brain vascular dysfunction of neonates in the clinical setting. Measurement of blood-brain barrier tight-junction proteins have shown promise as biomarkers for brain injury in the adult. Here we tested the biomarker potential of tight-junctions in the context of neonatal brain injury.Methods The levels of TJ-proteins (occluding, claudin-5, and zonula occludens protein 1) in both blood plasma and cerebrospinal fluid (CSF) as well as blood-brain barrier function via 14C-sucrose (342 Da) and Evans blue extravasation were measured in a hypoxia/ischemia brain-injury model in neonatal rats.Results Time-dependent changes of occludin and claudin-5 levels could be measured in blood and CSF after hypoxia/ischemia with males generally having higher levels than females. The levels of claudin-5 in CSF correlated with the severity of the brain injury at 24h post- hypoxia/ischemia. Simultaneously, we detected early increase in blood-brain barrier-permeability at 6 and 24h after hypoxia/ischemia.Conclusions Levels of circulating claudin-5 and occludin are increased after hypoxic/ischemic brain injuries and blood-brain barrier-impairment and have promise as early biomarkers for cerebral vascular dysfunction and as a tool for risk assessment of neonatal brain injuries.


2019 ◽  
Vol 153 (3) ◽  
pp. 413-425 ◽  
Author(s):  
Bo Yang ◽  
Junjie Xu ◽  
Liuhui Chang ◽  
Zhigang Miao ◽  
Dara Heang ◽  
...  

Pharmaceutics ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 399 ◽  
Author(s):  
Catarina Chaves ◽  
Xavier Declèves ◽  
Meryam Taghi ◽  
Marie-Claude Menet ◽  
Joelle Lacombe ◽  
...  

The blood–brain barrier (BBB) hinders the brain delivery of many anticancer drugs. In pediatric patients, diffuse intrinsic pontine glioma (DIPG) represents the main cause of brain cancer mortality lacking effective drug therapy. Using sham and DIPG-bearing rats, we analyzed (1) the brain distribution of 3-kDa-Texas red-dextran (TRD) or [14C]-sucrose as measures of BBB integrity, and (2) the role of major ATP-binding cassette (ABC) transporters at the BBB on the efflux of the irinotecan metabolite [3H]-SN-38. The unaffected [14C]-sucrose or TRD distribution in the cerebrum, cerebellum, and brainstem regions in DIPG-bearing animals suggests an intact BBB. Targeted proteomics retrieved no change in P-glycoprotein (P-gp), BCRP, MRP1, and MRP4 levels in the analyzed regions of DIPG rats. In vitro, DIPG cells express BCRP but not P-gp, MRP1, or MRP4. Dual inhibition of P-gp/Bcrp, or Mrp showed a significant increase on SN-38 BBB transport: Cerebrum (8.3-fold and 3-fold, respectively), cerebellum (4.2-fold and 2.8-fold), and brainstem (2.6-fold and 2.2-fold). Elacridar increased [3H]-SN-38 brain delivery beyond a P-gp/Bcrp inhibitor effect alone, emphasizing the role of another unidentified transporter in BBB efflux of SN-38. These results confirm a well-preserved BBB in DIPG-bearing rats, along with functional ABC-transporter expression. The development of chemotherapeutic strategies to circumvent ABC-mediated BBB efflux are needed to improve anticancer drug delivery against DIPG.


2019 ◽  
Vol 20 (7) ◽  
pp. 1632 ◽  
Author(s):  
Michelle Erickson ◽  
William Banks

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.


2020 ◽  
Vol 18 (12) ◽  
pp. 1237-1249 ◽  
Author(s):  
Ruiqing Kang ◽  
Marcin Gamdzyk ◽  
Cameron Lenahan ◽  
Jiping Tang ◽  
Sheng Tan ◽  
...  

It is well-known that stroke is one of the leading causes of death and disability all over the world. After a stroke, the blood-brain barrier subsequently breaks down. The BBB consists of endothelial cells surrounded by astrocytes. Microglia, considered the long-living resident immune cells of the brain, play a vital role in BBB function. M1 microglia worsen BBB disruption, while M2 microglia assist in repairing BBB damage. Microglia can also directly interact with endothelial cells and affect BBB permeability. In this review, we are going to discuss the mechanisms responsible for the dual role of microglia in BBB dysfunction after stroke.


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