scholarly journals Matrix Metalloproteinase-9 Mediates Hypoxia-Induced Vascular Leakage in the Brain via Tight Junction Rearrangement

2009 ◽  
Vol 30 (4) ◽  
pp. 837-848 ◽  
Author(s):  
Alexander T Bauer ◽  
Heinrich F Bürgers ◽  
Tamer Rabie ◽  
Hugo H Marti
Keyword(s):  
Inflammatory Responses ◽  
Vascular Leakage ◽  
Vascular Endothelial ◽  
Gap Formation ◽  
Edema Formation ◽  
Mmp Inhibitor ◽  
Vascular Structures ◽  
Endothelial Growth Factor ◽  
Metalloproteinase 9

Blood–brain barrier (BBB) disruption, resulting from loss of tight junctions (TJ) and activation of matrix metalloproteinases (MMPs), is associated with edema formation in ischemic stroke. Cerebral edema develops in a phasic manner and consists of both vasogenic and cytotoxic components. Although it is contingent on several independent mechanisms, involving hypoxic and inflammatory responses, the single effect of prolonged hypoxia on BBB integrity in vivo was not addressed so far. Exposing mice to normobaric hypoxia (8% oxygen for 48 h) led to a significant increase in vascular permeability associated with diminished expression of the TJ protein occludin. Immunofluorescence studies revealed that hypoxia resulted in disrupted continuity of occludin and zonula occludens-1 (Zo-1) staining with significant gap formation. Hypoxia increased gelatinolytic activity specifically in vascular structures and gel zymography identified MMP-9 as enzymatic source. Treatment with an MMP inhibitor reduced vascular leakage and attenuated disorganization of TJ. Inhibition of vascular endothelial growth factor (VEGF) attenuated vascular leakage and MMP-9 activation induced by hypoxia. In conclusion, our data suggest that hypoxia-induced edema formation is mediated by MMP-9-dependent TJ rearrangement by a mechanism involving VEGF. Therefore, inhibition of MMP-9 might provide the basis for therapeutic strategies to treat brain edema.

scholarly journals Effects of a synthetic PEG-ylated Tie-2 agonist peptide on endotoxemic lung injury and mortality

2011 ◽  
Vol 300 (6) ◽  
pp. L851-L862 ◽  
Author(s):  
Sascha David ◽  
Chandra C. Ghosh ◽  
Philipp Kümpers ◽  
Nelli Shushakova ◽  
Paul Van Slyke ◽  
...  
Keyword(s):  
Mouse Model ◽  
Lethal Dose ◽  
Phage Display Library ◽  
Vascular Leakage ◽  
Vascular Endothelial ◽  
Protective Effects ◽  
Gap Formation ◽  
Diabetic Ulcer ◽  
Vascular Endothelial Cadherin

A synthetic 7-mer, HHHRHSF, was recently identified by screening a phage display library for binding to the Tie-2 receptor. A polyethylene-oxide clustered version of this peptide, termed vasculotide (VT), was reported to activate Tie-2 and promote angiogenesis in a mouse model of diabetic ulcer. We hypothesized that VT administration would defend endothelial barrier function against sepsis-associated mediators of permeability, prevent lung vascular leakage arising in endotoxemia, and improve mortality in endotoxemic mice. In confluent human microvascular endothelial cells, VT prevented endotoxin-induced (lipopolysaccharides, LPS O111:B4) gap formation, loss of monolayer resistance, and translocation of labeled albumin. In 8-wk-old male C57Bl6/J mice given a ∼70% lethal dose of endotoxin (15 mg/kg ip), VT prevented lung vascular leakage and reversed the attenuation of lung vascular endothelial cadherin induced by endotoxemia. These protective effects of VT were associated with activation of Tie-2 and its downstream mediator, Akt. Echocardiographic studies showed only a nonsignificant trend toward improved myocardial performance associated with VT. Finally, we evaluated survival in this mouse model. Pretreatment with VT improved survival by 41.4% ( n = 15/group, P = 0.02) and post-LPS administration of VT improved survival by 33.3% ( n = 15/group, P = 0.051). VT-mediated protection from LPS lethality was lost in Tie-2 heterozygous mice, in agreement with VT's proposed receptor specificity. We conclude that this synthetic Tie-2 agonist, completely unrelated to endogenous Tie-2 ligands, is sufficient to activate the receptor and its downstream pathways in vivo and that the Tie-2 receptor may be an important target for therapeutic evaluation in conditions of pathological vascular leakage.

scholarly journals Manipulation of Quercetin and Melatonin in the Down-Regulation of HIF-1α, HSP-70 and VEGF Pathways in Rat’s Kidneys Induced by Hypoxic Stress

Dose-Response ◽  
2020 ◽  
Vol 18 (3) ◽  
pp. 155932582094979
Author(s):  
Aliah R. Alshanwani ◽  
Sameerah Shaheen ◽  
Laila M. Faddah ◽  
Ahlam M. Alhusaini ◽  
Hanaa M. Ali ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Histopathological Examination ◽  
Hemoglobin Concentration ◽  
Vascular Endothelial ◽  
Hsp 70 ◽  
Reactive Protein ◽  
Defensive Role ◽  
Factor Α ◽  
Endothelial Growth Factor

Hypoxia may lead to inflammatory responses by numerous signaling pathways. This investigation intended to inspect the defensive role of Quercetin (Quer) and/ or Melatonin (Mel) against reno toxicity induced by Sodium nitrite (Sod ntr). Sod ntr injection significantly decreased blood hemoglobin concentration (Hb) with a concurrent increase in serum tumor necrosis factor- α, interleukin-6, C-reactive protein, creatinine, and urea levels. Over protein-expression of vascular endothelial growth factor and heat shock, protein-70 and mRNA of HIF-1α were also observed. Pretreatment of the Sod ntr- injected rats with the aforementioned antioxidants; either alone or together significantly improved such parameters. Histopathological examination reinforced the previous results. It was concluded that the combined administration of Quer and Mel may be useful as a potential therapy against renal injury induced by Sod ntr. HIF-1α and HSP-70 are implicated in the induction of hypoxia and its treatment.

scholarly journals Inhibition of Hippo Signaling Improves Skin Lesions in a Rosacea-Like Mouse Model

2021 ◽  
Vol 22 (2) ◽  
pp. 931
Author(s):  
Jihyun Lee ◽  
Yujin Jung ◽  
Seo won Jeong ◽  
Ga Hee Jeong ◽  
Gue Tae Moon ◽  
...  
Keyword(s):  
Mouse Model ◽  
Signaling Pathway ◽  
Normal Skin ◽  
Skin Lesions ◽  
Hippo Signaling ◽  
Vascular Endothelial ◽  
Expression Levels ◽  
Hippo Signaling Pathway ◽  
Endothelial Growth Factor

The Hippo signaling pathway plays a key role in regulating organ size and tissue homeostasis. Hippo and two of its main effectors, yes-associated protein (YAP) and WWTR1 (WW domain-containing transcription regulator 1, commonly listed as TAZ), play critical roles in angiogenesis. This study investigated the role of the Hippo signaling pathway in the pathogenesis of rosacea. We performed immunohistochemical analyses to compare the expression levels of YAP and TAZ between rosacea skin and normal skin in humans. Furthermore, we used a rosacea-like BALB/c mouse model induced by LL-37 injections to determine the roles of YAP and TAZ in rosacea in vivo. We found that the expression levels of YAP and TAZ were upregulated in patients with rosacea. In the rosacea-like mouse model, we observed that the clinical features of rosacea, including telangiectasia and erythema, improved after the injection of a YAP/TAZ inhibitor. Additionally, treatment with a YAP/TAZ inhibitor reduced the expression levels of YAP and TAZ and diminished vascular endothelial growth factor (VEGF) immunoreactivity in the rosacea-like mouse model. Our findings suggest that YAP/TAZ inhibitors can attenuate angiogenesis associated with the pathogenesis of rosacea and that both YAP and TAZ are potential therapeutic targets for patients with rosacea.

scholarly journals Organic Nanocarriers for Bevacizumab Delivery: An Overview of Development, Characterization and Applications

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4127
Author(s):  
Aline de Cristo Soares Alves ◽  
Franciele Aline Bruinsmann ◽  
Silvia Stanisçuaski Guterres ◽  
Adriana Raffin Pohlmann
Keyword(s):  
Monoclonal Antibody ◽  
Physicochemical Characterization ◽  
Vascular Endothelial ◽  
Organic Nanoparticles ◽  
Humanized Monoclonal Antibody ◽  
Angiogenesis Process ◽  
Endothelial Growth Factor ◽  
Drug Pharmacokinetics

Bevacizumab (BCZ) is a recombinant humanized monoclonal antibody against the vascular endothelial growth factor, which is involved in the angiogenesis process. Pathologic angiogenesis is observed in several diseases including ophthalmic disorders and cancer. The multiple administrations of BCZ can cause adverse effects. In this way, the development of controlled release systems for BCZ delivery can promote the modification of drug pharmacokinetics and, consequently, decrease the dose, toxicity, and cost due to improved efficacy. This review highlights BCZ formulated in organic nanoparticles providing an overview of the physicochemical characterization and in vitro and in vivo biological evaluations. Moreover, the main advantages and limitations of the different approaches are discussed. Despite difficulties in working with antibodies, those nanocarriers provided advantages in BCZ protection against degradation guaranteeing bioactivity maintenance.

Effect of co-treatment with doxorubicin and verapamil loaded into chitosan nanoparticles on diethylnitrosamine-induced hepatocellular carcinoma in mice

2020 ◽  
Vol 39 (11) ◽  
pp. 1528-1544 ◽  
Author(s):  
HE Abo Mansour ◽  
MM El-Batsh ◽  
NS Badawy ◽  
ET Mehanna ◽  
NM Mesbah ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Anticancer Activity ◽  
Hepg2 Cells ◽  
Chitosan Nanoparticles ◽  
B Cell Lymphoma ◽  
Favorable Effect ◽  
Vascular Endothelial ◽  
Factor Α ◽  
Endothelial Growth Factor

This study aimed to investigate the potential role of co-treatment with doxorubicin (DOX) and verapamil (VRP) nanoparticles in experimentally induced hepatocellular carcinoma in mice and to investigate the possible mechanisms behind the potential favorable effect of the co-treatment. DOX and VRP were loaded into chitosan nanoparticles (CHNPs), and cytotoxicity of loaded and unloaded drugs against HepG2 cells was evaluated. Male albino mice were divided into eight groups ( n = 15): (1) normal control, (2) diethylnitrosamine, (3) CHNPs, (4) free DOX, (5) CHNPs DOX, (6) free VRP, (7) CHNPs VRP, and (8) CHNPs DOX + CHNPs VRP. Either VRP or DOX loaded into CHNPs showed stronger growth inhibition of HepG2 cells than their free forms. DOX or VRP nanoparticles displayed pronounced anticancer activity in vivo through the decline of vascular endothelial growth factor and B cell lymphoma-2 contents in liver tissues, upregulation of antioxidant enzymes, and downregulation of multidrug resistance 1. Moreover, reduced cardiotoxicity was evident from decreased level of tumor necrosis factor-α and malondialdehyde in heart tissues coupled with decreased serum activity of creatine kinase-myocardial band and lactate dehydrogenase. Co-treatment with CHNPs DOX and CHNPs VRP showed superior results versus other treatments. Liver sections from the co-treatment group revealed the absence of necrosis, enhanced apoptosis, and nearly normal hepatic lobule architecture. Co-treatment with CHNPs DOX and CHNPs VRP revealed enhanced anticancer activity and decreased cardiotoxicity versus the corresponding free forms.

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