Polyethylenimine Triggers Dll4 Degradation to Regulate Angiogenesis In Vitro.

The Dll4-Notch signaling pathway plays a crucial role in the regulation of angiogenesis and is a promising therapeutic target for diseases associated with abnormal angiogenesis, such as cancer and ophthalmic diseases. Here, we find that polyethylenimine (PEI), a cationic polymer widely used as nucleic acid transfection reagents, can target the Notch ligand Dll4. By immunostaining and immunoblotting, we demonstrate that PEI significantly induces the clearance of cell-surface Dll4 and facilitates its degradation through the lysosomal pathway.

An MMP-9 exclusive neutralizing antibody attenuates blood-brain barrier breakdown in mice with stroke and reduces stroke patient-derived MMP-9 activity.

Rapid upregulation of matrix metalloproteinase 9 (MMP-9) leads to blood-brain barrier (BBB) breakdown following stroke, but no MMP-9 inhibitors have been approved in clinic largely due to their low specificities and side effects. Here, we explored the therapeutic potential of a human IgG monoclonal antibody (mAb), L13, which was recently developed with exclusive neutralizing specificity to MMP-9, nanomolar potency, and biological function, using mouse stroke models and stroke patient samples. We found that L13 treatment at the onset of reperfusion following cerebral ischemia or after intracranial hemorrhage (ICH) significantly reduced brain tissue injury and improved the neurological outcomes of mice.

Lithium attenuates blood-brain barrier damage and brain edema following intracerebral hemorrhage via an endothelial Wnt/β-catenin signaling-dependent mechanism in mice.

Background: Vasogenic cerebral edema resulting from blood-brain barrier (BBB) damage aggravates the devastating consequences of intracerebral hemorrhage (ICH). Although augmentation of endothelial Wnt/β-catenin signaling substantially alleviates BBB breakdown in animals, no agents based on this mechanism are clinically available. Lithium is a medication used to treat bipolar mood disorders and can upregulate Wnt/β-catenin signaling.

Normalization of non-canonical Wnt signalings does not compromise blood-brain barrier protection conferred by upregulating endothelial Wnt/β-catenin signaling following ischemic stroke.

Background: Endothelial canonical (Wnt/β-catenin) and non-canonical Wnt signalings (Wnt/PCP and Wnt/Ca ) promote blood-brain barrier (BBB) development and antagonize each other. However, the effects of ischemic stroke on endothelial canonical and non-canonical Wnt signalings are unclear. Further, how non-canonical Wnt signalings are influenced by upregulation of endothelial Wnt/β-catenin signaling and subsequently affect BBB function following ischemic stroke have not been studied.

Lithium alleviates blood-brain barrier breakdown after cerebral ischemia and reperfusion by upregulating endothelial Wnt/β-catenin signaling in mice.

Although upregulation of endothelial Wnt/β-catenin signaling may be used to treat blood-brain barrier (BBB) breakdown caused by cerebral ischemia/reperfusion injury, no agents based on this mechanism are available clinically. Lithium, a medication used for treating bipolar mood disorders, upregulates Wnt/β-catenin signaling, but whether lithium alleviates BBB breakdown after ischemic stroke by upregulating endothelial Wnt/β-catenin signaling is unclear. Here, we evaluated the BBB-protective effect of lithium in adult mice with 1-h middle cerebral artery occlusion and 48-h reperfusion (MCAO/R) by determining neurological outcomes, BBB function and related molecular components.

The Combination of Human Urinary Kallidinogenase and Mild Hypothermia Protects Adult Rats Against Hypoxic-Ischemic Encephalopathy-Induced Injury by Promoting Angiogenesis and Regeneration.

: Human Urinary Kallidinogenase (HUK) is a tissue kallikrein that plays neuroprotective role in ischemic conditions via different mechanisms. Mild hypothermia (MH) is another robust neuroprotectant that reduces mortality but does not profoundly ameliorate the neurological outcome in hypoxic-ischemic encephalopathy (HIE) patients. However, whether the combination of HUK and MH can be used as a promising neuroprotective treatment in HIE is unknown.

TFP5 peptide, derived from CDK5-activating cofactor p35, provides neuroprotection in early-stage of adult ischemic stroke.

Cyclin-dependent kinase 5 (CDK5) is a multifaceted protein shown to play important roles in the central nervous system. Abundant evidence indicates that CDK5 hyperactivities associated with neuronal apoptosis and death following ischemic stroke. CDK5 activity increases when its cofactor p35 cleaves into p25 during ischemia.

TFP5 is comparable to mild hypothermia in improving neurological outcomes in early-stage ischemic stroke of adult rats.

Aim: We compared the efficacy of a modified truncated 24-aa peptide (TFP5), derived from the cyclin-dependent kinase 5 (CDK5)-activating cofactor p35, with mild hypothermia (MH), and determined whether the efficacy of TFP5 is affected by MH.

Methods: Ischemic stroke was induced in adult male Sprague-Dawley rats for 2h. Immediately after initiating reperfusion, TFP5, MH, or the combination of the two were administrated.

Interrupted intracarotid artery cold saline infusion as an alternative method for neuroprotection after ischemic stroke.

Object: Intracarotid artery cold saline infusion (ICSI) is an effective method for protecting brain tissue, but its use is limited because of undesirable secondary effects, such as severe decreases in hematocrit levels, as well as its relatively brief duration. In this study, the authors describe and investigate the effects of a novel ICSI pattern (interrupted ICSI) relative to the traditional method (uninterrupted ICSI).

Methods: Ischemic strokes were induced in 85 male Sprague-Dawley rats by occluding the middle cerebral artery for 3 hours using an intraluminal filament.

Therapeutic time window of hypothermia is broader than cerebral artery flushing in carotid saline infusion after transient focal ischemic stroke in rats.

Object: Intracarotid cold saline infusion (ICSI) protects against ischemic stroke not only due to the resulting hypothermia, but also as a result of the cerebral artery flushing. To assess the relative benefit of hypothermia and cerebral artery flushing in neuroprotection, hypothermic and normothermic saline infusions were administrated over a serial time points after the initiation of reperfusion in a rat ischemia model.

Methods: Ischemic strokes were induced in Sprague-Dawley rats (n = 115) by occluding the middle cerebral artery for 2 hours using an intraluminal filament.

Intra-carotid cold magnesium sulfate infusion induces selective cerebral hypothermia and neuroprotection in rats with transient middle cerebral artery occlusion.

Local hypothermia induced by intra-arterial infusion of cold saline reduces brain injury in ischemic stroke. Administration of magnesium sulfate through the internal carotid artery is also known to reduce ischemic brain damage. The neuroprotective effects of combination therapy with local endovascular hypothermia and intra-carotid magnesium sulfate infusion has not been evaluated.

[Comparison of neuroprotective effects of hypothermia induced by different methods in rats with early cerebral ischemia].

Objective: To compare the neuroprotective effects of intracarotid cold saline infusion (ICSI), ice cap and systemic cooling in rats with early cerebral ischemia.

Methods: SD rats were randomly divided into model group, ice cap group, systemic cooling group and ICSI group (n=13). Cerebral ischemia was induced by middle cerebral artery occlusion (MCAO) for 2 h.