Dataset Information

Exploring the role of MKK7 in excitotoxicity and cerebral ischemia: a novel pharmacological strategy against brain injury.

ABSTRACT: Excitotoxicity following cerebral ischemia elicits a molecular cascade, which leads to neuronal death. c-Jun-N-terminal kinase (JNK) has a key role in excitotoxic cell death. We have previously shown that JNK inhibition by a specific cell-permeable peptide significantly reduces infarct size and neuronal death in an in vivo model of cerebral ischemia. However, systemic inhibition of JNK may have detrimental side effects, owing to blockade of its physiological function. Here we designed a new inhibitor peptide (growth arrest and DNA damage-inducible 45? (GADD45?-I)) targeting mitogen-activated protein kinase kinase 7 (MKK7), an upstream activator of JNK, which exclusively mediates JNK's pathological activation. GADD45?-I was engineered by optimizing the domain of the GADD45?, able to bind to MKK7, and by linking it to the TAT peptide sequence, to allow penetration of biological membranes. Our data clearly indicate that GADD45?-I significantly reduces neuronal death in excitotoxicity induced by either N-methyl-D-aspartate exposure or by oxygen-glucose deprivation in vitro. Moreover, GADD45?-I exerted neuroprotection in vivo in two models of ischemia, obtained by electrocoagulation and by thromboembolic occlusion of the middle cerebral artery (MCAo). Indeed, GADD45?-I reduced the infarct size when injected 30?min before the lesion in both models. The peptide was also effective when administrated 6?h after lesion, as demonstrated in the electrocoagulation model. The neuroprotective effect of GADD45?-I is long lasting; in fact, 1 week after MCAo the infarct volume was still reduced by 49%. Targeting MKK7 could represent a new therapeutic strategy for the treatment of ischemia and other pathologies involving MKK7/JNK activation. Moreover, this new inhibitor can be useful to further dissect the physiological and pathological role of the JNK pathway in the brain.

SUBMITTER: Vercelli A

PROVIDER: S-EPMC4558515 | biostudies-literature | 2015 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Exploring the role of MKK7 in excitotoxicity and cerebral ischemia: a novel pharmacological strategy against brain injury.

Vercelli A A Biggi S S Sclip A A Repetto I E IE Cimini S S Falleroni F F Tomasi S S Monti R R Tonna N N Morelli F F Grande V V Stravalaci M M Biasini E E Marin O O Bianco F F di Marino D D Borsello T T

Cell death & disease 20150813

Excitotoxicity following cerebral ischemia elicits a molecular cascade, which leads to neuronal death. c-Jun-N-terminal kinase (JNK) has a key role in excitotoxic cell death. We have previously shown that JNK inhibition by a specific cell-permeable peptide significantly reduces infarct size and neuronal death in an in vivo model of cerebral ischemia. However, systemic inhibition of JNK may have detrimental side effects, owing to blockade of its physiological function. Here we designed a new inhi ...[more]

PMID: 26270349

Similar Datasets

Project description:Selective brain hypothermia is considered an effective treatment for neuronal injury after stroke, and avoids the complications of general hypothermia. However, the mechanisms by which selective brain hypothermia affects mitochondrial fission remain unknown. In this study, we investigated the effect of selective brain hypothermia on the expression of fission 1 (Fis1) protein, a key factor in the mitochondrial fission system, during focal cerebral ischemia/reperfusion injury. Sprague-Dawley rats were divided into four groups. In the sham group, the carotid arteries were exposed only. In the other three groups, middle cerebral artery occlusion was performed using the intraluminal filament technique. After 2 hours of occlusion, the filament was slowly removed to allow blood reperfusion in the ischemia/reperfusion group. Saline, at 4°C and 37°C, were perfused through the carotid artery in the hypothermia and normothermia groups, respectively, followed by restoration of blood flow. Neurological function was assessed with the Zea Longa 5-point scoring method. Cerebral infarct volume was assessed by 2,3,5-triphenyltetrazolium chloride staining, and apoptosis was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining. Fis1 and cytosolic cytochrome c levels were assessed by western blot assay. Fis1 mRNA expression was assessed by quantitative reverse transcription-polymerase chain reaction. Mitochondrial ultrastructure was evaluated by transmission electron microscopy. Compared with the sham group, apoptosis, Fis1 protein and mRNA expression and cytosolic cytochrome c levels in the cortical ischemic penumbra and cerebral infarct volume were increased after reperfusion in the other three groups. These changes caused by cerebral ischemia/reperfusion were inhibited in the hypothermia group compared with the normothermia group. These findings show that selective brain hypothermia inhibits Fis1 expression and reduces apoptosis, thereby ameliorating focal cerebral ischemia/reperfusion injury in rats. Experiments were authorized by the Ethics Committee of Qingdao Municipal Hospital of China (approval No. 2019008).

Project description:Ischemic stroke is one of the most common causes of mortality worldwide and is a primary cause of disability and mortality in adults. There is an unmet need for drugs that can effectively treat ischemic stroke. Hence, the present study explored the neuroprotective effects of andrographolide (Andro) in a mouse model of bilateral common carotid artery occlusion, and systematically evaluated the potential mechanisms underlying its effects. The effects of Andro on mouse brain tissue following cerebral ischemia‑reperfusion injury (CIRI) were evaluated by histopathological (H&E and Nissl) and immunofluorescence [glial fibrillary acidic protein (GFAP) and neuronal nuclei (NeuN)] staining. A traditional Chinese medicine‑based network pharmacology method was performed to establish and analyze compound‑target‑disease and function‑pathway networks in order to elucidate the possible mechanisms responsible for the protective role of Andrographis paniculata in CIRI. In addition, western blot analysis and RT‑qPCR was performed to evaluate the expression and activation of signaling proteins predicted to be involved in this mechanism. The amelioration of histopathological alterations was observed in mice pre‑treated with Andro. Immunofluorescence staining revealed that Andro decreased the expression of GFAP and increased the expression of NeuN, and significantly decreased the levels of pro‑inflammatory cytokines (IL‑1β, IL‑6 and TNF‑α). Network pharmacology analysis revealed that neuroinflammatory response and apoptosis were associated with the effects of Andrographis paniculata on CIRI. Western blot analysis revealed that the mice pre‑treated with Andro exhibited an upregulated protein expression of tropomyosin receptor kinase B (TrkB), p‑PI3K and p‑Akt, as well as a decrease in the expression of GFAP and an increase in the expression of NeuN. In addition, the data of RT‑qPCR indicated that the mice pre‑treated with Andro exhibited a significantly decreased expression of encoding IL‑1β mRNA, IL‑6 mRNA and TNF‑α mRNA in the brain compared to the untreated mice following CIRI. On the whole, the findings of the present study suggest that pre‑treatment with Andro exerts a protective effect against CIRI, which may be partly related to its potential to reduce neuroinflammatory response and apoptosis in patients with stroke.

Dataset Information

Exploring the role of MKK7 in excitotoxicity and cerebral ischemia: a novel pharmacological strategy against brain injury.

Publications

Exploring the role of MKK7 in excitotoxicity and cerebral ischemia: a novel pharmacological strategy against brain injury.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets