Disruption of the Blood-Brain Barrier by Extracellular Vesicles From Preeclampsia Plasma and Hypoxic Placentae: Attenuation by Magnesium Sulfate

Author(s):  
José León ◽  
Jesenia Acurio ◽  
Lina Bergman ◽  
Juán López ◽  
Anna Karin Wikström ◽  
...  

Preeclampsia, a pregnancy-related endothelial disorder, is associated with both cardiovascular and cerebrovascular complications. Preeclampsia requires the presence of a placenta as part of its pathophysiology, yet the role of this organ in the cerebrovascular complications remains unclear. Research has shown that circulating small extracellular vesicles (also known as exosomes) present in preeclampsia plasma can generate endothelial dysfunction, but it is unclear whether the impairment of function of brain endothelial cells at the blood-brain barrier is secondary to plasma-derived or placental-derived exosomes. In this study, we evaluated the effect of small extracellular vesicles isolated from plasma samples of women with preeclampsia (n=12) and women with normal pregnancy (n=11) as well as from human placental explants from normotensive pregnancies (n=6) subjected to hypoxia (1% oxygen) on the integrity of the blood-brain barrier, using both in vitro and animal models. Exposure of human-derived brain endothelial cell monolayers to plasma and plasma-derived small extracellular vesicles from preeclamptic pregnancies increased the permeability and reduced the transendothelial electrical resistance. A similar outcome was observed with hypoxic placental-derived small extracellular vesicles, which also increased the permeability to Evan’s blue in the brain of C57BL6 nonpregnant mice. Cotreatment with magnesium sulfate reversed the effects elicited by plasma, plasma-derived, and hypoxic placental-derived small extracellular vesicles in the employed models. Thus, circulating small extracellular vesicles in plasma from women with preeclampsia or from hypoxic placentae disrupt the blood-brain barrier, which can be prevented using magnesium sulfate. These findings provide new insights into the pathophysiology of cerebral complications associated with preeclampsia.

Neuroscience ◽  
2017 ◽  
Vol 350 ◽  
pp. 146-157 ◽  
Author(s):  
Takashi Machida ◽  
Shinya Dohgu ◽  
Fuyuko Takata ◽  
Junichi Matsumoto ◽  
Ikuya Kimura ◽  
...  

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.


2013 ◽  
Vol 33 (4) ◽  
pp. 575-582 ◽  
Author(s):  
Quoc Bao Dang ◽  
Bertrand Lapergue ◽  
Alexy Tran-Dinh ◽  
Devy Diallo ◽  
Juan-Antonio Moreno ◽  
...  

Breakdown of the blood–brain barrier (BBB) is a key step associated with ischemic stroke and its increased permeability causes extravasation of plasma proteins and circulating leukocytes. Polymorphonuclear neutrophil (PMN) proteases may participate in BBB breakdown. We investigated the role of PMNs in ischemic conditions by testing their effects on a model of BBB in vitro, under oxygen-glucose deprivation (OGD) to mimic ischemia, supplemented or not with high-density lipoproteins (HDLs) to assess their potential protective effects. Human cerebral endothelial cells cultured on transwells were incubated for 4 hours under OGD conditions with or without PMNs and supplemented or not with HDLs or alpha-1 antitrypsin (AAT, an elastase inhibitor). The integrity of the BBB was then assessed and the effect of HDLs on PMN-induced proteolysis of extracellular matrix proteins was evaluated. The release of myeloperoxidase and matrix metalloproteinase 9 (MMP-9) by PMNs was quantified. Polymorphonuclear neutrophils significantly increased BBB permeability under OGD conditions via proteolysis of extracellular matrix proteins. This was associated with PMN degranulation. Addition of HDLs or AAT limited the proteolysis and associated increased permeability by inhibiting PMN activation. Our results suggest a deleterious, elastase-mediated role of activated PMNs under OGD conditions leading to BBB disruption that could be inhibited by HDLs.


Author(s):  
Fang Niu ◽  
Ke Liao ◽  
Guoku Hu ◽  
Shamsudheen Moidunny ◽  
Sabita Roy ◽  
...  

HIV trans-activator of transcription (Tat), one of the cytotoxic proteins secreted from HIV-infected cells, is also known to facilitate chemokine-mediated transmigration of monocytes into the brain leading, in turn, to neuroinflammation and thereby contributing to the development of HIV-associated neurocognitive disorders (HAND). The mechanism(s) underlying HIV Tat-mediated enhancement of monocyte transmigration, however, remain largely unknown. CXC chemokine receptor 3 (CXCR3) that is expressed by the peripheral monocytes is known to play a role in the monocyte influx and accumulation. In the present study, we demonstrate for the first time that exposure of human monocytes to HIV Tat protein resulted in upregulated expression of CXCR3 leading, in turn, to increased monocyte transmigration across the blood–brain barrier (BBB) both in the in vitro and in vivo model systems. This process involved activation of toll-like receptor 4 (TLR4), with downstream phosphorylation and activation of TANK-binding kinase 1 (TBK1), and subsequent phosphorylation and nuclear translocation of interferon regulatory factor 3 (IRF3), ultimately leading to enhanced expression of CXCR3 in human monocytes. These findings imply a novel molecular mechanism underlying HIV Tat-mediated increase of monocyte transmigration across the BBB, while also implicating a novel role of CXCR3-dependent monocyte transmigration in HIV Tat-mediated neuroinflammation.


2012 ◽  
Vol 32 (4) ◽  
pp. 628-632 ◽  
Author(s):  
Thorsten Pflanzner ◽  
Benjamin Petsch ◽  
Bettina André-Dohmen ◽  
Andreas Müller-Schiffmann ◽  
Sabrina Tschickardt ◽  
...  

The blood—brain barrier (BBB) facilitates amyloid-β (Aβ) exchange between the blood and the brain. Here, we found that the cellular prion protein (PrPc), a putative receptor implicated in mediating Aβ neurotoxicity in Alzheimer's disease (AD), participates in Aβ transcytosis across the BBB. Using an in vitro BBB model, [125I]-Aβ1–40 transcytosis was reduced by genetic knockout of PrPc or after addition of a competing PrPc-specific antibody. Furthermore, we provide evidence that PrPc is expressed in endothelial cells and, that monomeric Aβ1–40 binds to PrPc. These observations provide new mechanistic insights into the role of PrPc in AD.


2017 ◽  
Vol 55 (6) ◽  
pp. 5321-5336 ◽  
Author(s):  
N. Caporarello ◽  
M. Olivieri ◽  
M. Cristaldi ◽  
M. Scalia ◽  
M. A. Toscano ◽  
...  

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