Protective Effects of UCF-101 on Cerebral Ischemia-Reperfusion (CIR) is Depended on the MAPK/p38/ERK Signaling Pathway

Ucf-101 alleviates Ischaemia/Reperfusion induced retinal inflammation and injury via suppressing oxidative damage

The Omi/HtrA2 inhibitor 5-[5-(2-nitrophenyl) furfuryliodine]-1,3-diphenyl-2-thiobarbituric acid (Ucf-101) has shown neuroprotective effects in the central nervous system. However, whether Ucf-101 can protect retinal ganglion cells (RGCs) after retinal ischemia/reperfusion (IR) has not been investigated. We aimed to investigate the effects of Ucf-101 on RGCs apoptosis and inflammation after IR-induced retinal injury in mice. We injected Ucf-101 into the mouse vitreous body immediately after IR injury. After 7 days, hematoxylin and eosin staining was conducted to assess retinal tissue damage. Next, retrograde labeling with FluoroGold, counting of RGCs and TUNEL staining were conducted to evaluate apoptosis. Immunohistochemistry, immunofluorescence staining, and western blotting were conducted to analyze protein levels. IR injury-induced retinal tissue damage could be prevented by Ucf-101 treatment. The number of TUNEL-positive RGCs was reduced by Ucf-101 treatment in mice with IR injury. Ucf-101 treatment inhibited the upregulation of Bax, cleaved caspase-3 and cleaved caspase-9 and activated the JNK/ERK/P38 signaling pathway. Furthermore, Ucf-101 treatment inhibited the upregulation of glial fibrillary acidic protein (GFAP), vimentin, Iba1 and CD68 in mice with IR injury. Ucf-101 prevents retinal tissue damage, improves the survival of RGCs, and suppresses microglial overactivation after IR injury. Ucf-101 might be a potential target to prevent RGCs apoptosis and inflammation in neurodegenerative eye diseases.

Mitochondrial quality control proteases and their modulation for cancer therapy

Mitochondria, the main provider of energy in eukaryotic cells, contains more than 1000 different proteins and is closely related to the development of cells. However, damaged proteins impair mitochondrial function, further contributing to several human diseases. Evidence shows mitochondrial proteases are critically important for protein maintenance. Most importantly, quality control enzymes exert a crucial role in the modulation of mitochondrial functions by degrading misfolded, aged, or superfluous proteins. Interestingly, cancer cells thrive under stress conditions that damage proteins, so targeting mitochondrial quality control proteases serves as a novel regulator for cancer cells. Not only that, mitochondrial quality control proteases have been shown to affect mitochondrial dynamics by regulating the morphology of optic atrophy 1 (OPA1), which is closely related to the occurrence and progression of cancer. In this review, we introduce mitochondrial quality control proteases as promising targets and related modulators in cancer therapy with a focus on caseinolytic protease P (ClpP), Lon protease (LonP1), high-temperature requirement protein A2 (HrtA2), and OMA-1. Further, we summarize our current knowledge of the advances in clinical trials for modulators of mitochondrial quality control proteases. Overall, the content proposed above serves to suggest directions for the development of novel antitumor drugs.

PD98059 protects SH-SY5Y cells against oxidative stress in oxygen-glucose deprivation/reperfusion

Mitochondria play a key role in the cerebral ischemia-reperfusion injury. Although the extracellular signal-regulated kinase 1/2 inhibitor PD98059 (PD) is a selective and reversible flavonoid that can protect the mitochondria in a rat model of cardiac arrest/cardiopulmonary resuscitation, its role requires further confirmation. In this study, we investigated whether PD could maintain mitochondrial homeostasis and decrease reactive oxygen species (ROS) production in neuroblastoma (SH-SY5Y) cells exposed to oxygen-glucose deprivation/reperfusion (OGD/R). PD improved the mitochondrial morphology and function, reversed the increase in ROS production and cell apoptosis, and reduced total-superoxide dismutase and Mn-superoxide dismutase activities induced by OGD/R. PD decreases ROS production and improves mitochondrial morphology and function, protecting SH-SY5Y cells against OGD/R-induced injury.

Coriolus versicolor polysaccharides (CVP) regulates neuronal apoptosis in cerebral ischemia-reperfusion injury via the p38MAPK signaling pathway

Background

This study aims to investigate the regulation of herbal polysaccharide, Coriolus versicolor polysaccharides (CVP), on neuronal apoptosis in a rat cerebral ischemia-reperfusion injury (CIRI) model. We also intend to explore the mechanisms and effectiveness of CVP in the treatment of neuronal apoptosis in CIRI rats, including neurological function, cerebral infarction volume, inflammatory factors, and the p38 mitogen-activated protein kinase (p38MAPK) signaling pathway as well as its downstream protein cleaved-Caspase-3.

Methods

A CIRI model was established in rats using the Longa method of middle cerebral artery occlusion. Neurological function scores and cerebral infarction volumes were measured in CIRI rats. Annexin V-fluorescein isothiocyanate (FITC) were used to measure neuronal apoptosis in CIRI rats. The levels of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in CIRI rats were determined using enzyme-linked immunosorbent assay (ELISA). A western blot assay was used to measure the protein expression levels of p38MAPK, phospho-p38MAPK (p-p38MAPK), Bcl-2, Bax and cleaved-Caspase-3 in brain tissue of CIRI rats.

Results

CVP can effectively improve the neurological function of rats after 6, 12, 24, and 48 h of CIRI. It can also improve the behavioral test, reduce the cerebral infarction volume and inhibit the apoptosis of nerve cells in CIRI rats. The protein expression levels of p-p38MAPK and cleaved-Caspase-3 exhibited a decreasing trend following CVP administration.

Conclusions

CVP can significantly reduce the pathological characteristics of CIRI in rats and inhibit the apoptosis of nerve cells around the lesions. The mechanism of its effectiveness is related to inhibiting the activation of the p38MAPK signaling pathway.

MiR-17-5p inhibits cerebral hypoxia/reoxygenationinjury by targeting PTEN through regulation of PI3K/AKT/mTOR signaling pathway

OBJECTIVE

To investigate the role and mechanism of miR-17-5p in cerebral hypoxia/reoxygenation (H/R)-induced apoptosis.

METHODS

The present study used human brain microvascular endothelial cells (HBMVECs) to establish cerebral H/R model. MTT was used to measure the cell viability. Flow cytometry was used to detect the cell apoptosis. The interaction between miR-17-5p and PTEN was determined using dual luciferase reporter assay. RT-qPCR and Western blotting were used for determination of the expression of miR-17-5p, PTEN, apoptosis- and PI3K/AKT/mTOR signalling-related proteins.

RESULTS

The cell viability and the expression of miR-17-5p were obviously down-regulated while the expression of PTEN was obviously up-regulated in H/R cells. The cell viability was remarkably enhanced, and the cell apoptosis induced by H/R injury was dramatically reduced when miR-17-5p was overexpressed in HBMVECs under H/R condition, which was reversed by overexpression of PTEN. Dual luciferase reporter assay showed PTEN was a direct target of miR-17-5p. Treatment of PI3K inhibitor LY294002 significantly increased the apoptosis rate of HBMVECs, and this effect was significantly reversed by transfection of miR-17-5p mimics, while further dramatically enhanced by overexpression of PTEN.

CONCLUSION

MiR-17-5p could ameliorate cerebral I/R injury-induced cell apoptosis by directly targeting PTEN and regulation of PI3K/AKT/mTOR signalling.

Iridoid glycosides from Radix Scrophulariae attenuates focal cerebral ischemia‑reperfusion injury via inhibiting endoplasmic reticulum stress‑mediated neuronal apoptosis in rats

Iridoid glycosides of Radix Scrophulariae (IGRS) are a group of the major bioactive components from Radix Scrophulariae with extensive pharmacological activities. The present study investigated the effects of IGRS on cerebral ischemia‑reperfusion injury (CIRI) and explored its potential mechanisms of action. A CIRI model in rats was established by occlusion of the right middle cerebral artery for 90 min, followed by 24 h of reperfusion. Prior to surgery, 30, 60 or 120 mg/kg IGRS was administered to the rats once a day for 7 days. Then, the neurological scores, brain edema and volume of the cerebral infarction were measured. The apoptosis index was determined by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling. The effects of IGRS on the histopathology of the cortex in brain tissues and the endoplasmic reticulum ultrastructure in the hippocampus were analyzed. Finally, the expression of endoplasmic reticulum stress (ERS)‑regulating mediators, endoplasmic reticulum chaperone BiP (GRP78), DNA damage‑inducible transcript 3 protein (CHOP) and caspase‑12, were detected by reverse transcription quantitative polymerase chain reaction (RT‑qPCR) and western blot analysis. The volume of cerebral infarction and brain water content in the IGRS‑treated groups treated at doses of 60 and 120 mg/kg were decreased significantly compared with the Model group. The neurological scores were also significantly decreased in the IGRS‑treated groups. IGRS treatment effectively decreased neuronal apoptosis resulting from CIRI‑induced neuron injury. In addition, the histopathological damage and the endoplasmic reticulum ultrastructure injury were partially improved in CIRI rats following IGRS treatment. RT‑qPCR and western blot analysis data indicated that IGRS significantly decreased the expression levels of GRP78, CHOP and caspase‑12 at both mRNA and protein levels. The results of the present study demonstrated that IGRS exerted a protective effect against CIRI in brain tissue via the inhibition of apoptosis and ERS.

Sulbactam Protects Hippocampal Neurons Against Oxygen-Glucose Deprivation by Up-Regulating Astrocytic GLT-1 via p38 MAPK Signal Pathway

Sulbactam is an atypical β-lactam medication and reported to be neuroprotective by up-regulating glial glutamate transporter-1 (GLT-1) in rats. The present study was undertaken to study the role of p38 MAPK signal pathway in sulbactam induced up-regulation of GLT-1 expression in astrocytes and anti-ischemic effect. Neuron-astrocyte co-cultures and astrocyte cultures from neonatal Wistar rats were used. Cerebral ischemia was mimicked by oxygen-glucose deprivation (OGD). Hoechst (HO)/propidium iodide (PI) double fluorescence staining and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay were used to evaluate neuronal death and cell viability, respectively. Immunocytochemistry and Western blot were used to detect protein expressions. Sulbactam pre-incubation significantly and dose-dependently prevented neuronal death and decline in cell viability induced by OGD in neuron-astrocyte co-cultures, and upregulated GLT-1 expression in astrocyte cultures endured OGD, which suggested that sulbactam might protect neurons against OGD by up-regulating astrocytic GLT-1 expression. It was further shown that the phosphorylated-p38 MAPK expression in astrocytes was up-regulated after the sulbactam pre-incubation and this up-regulation was moderate in amplitude. Especially, the time course of the up-regulation of phosphorylated-p38 MAPK was obviously earlier than that of GLT-1, which suggested possibility that p38 MAPK might be an upstream signal for GLT-1 up-regulation induced by sulbactam. We further found that SB203580, the specific inhibitor of p38 MAPK, dose-dependently inhibited the GLT-1 up-regulation induced by sulbactam either in non- or OGD-treated astrocytes and the protective effect of sulbactam on co-cultured neurons against OGD. Taken together, it might be concluded that sulbactam protects cerebral neurons against OGD by up-regulating astrocytic GLT-1 expression via p38 MAPK signal pathway.

Hydrogen saline suppresses neuronal cell apoptosis and inhibits the p38 mitogen‑activated protein kinase‑caspase‑3 signaling pathway following cerebral ischemia‑reperfusion injury

Cerebral ischemia-reperfusion injury (CIRI) is a serious pathological disease that is associated with a high rate death and disability. Saturated hydrogen (H₂) saline exhibits brain protective functions through anti-inflammatory, antioxidant and antiapoptotic effects. The present study investigated the potential treatment effects of H₂ on CIRI. In addition, the potential protective mechanisms of H₂ in the prevention of CIRI were investigated. Adult, male Sprague-Dawley rats (n=60) were randomly divided into the following three groups: Sham-operated group; IR group; and IR + H₂ group (0.6 mmol/l, 0.5 ml/kg/day). Hematoxylin and eosin, and TUNEL staining were performed for histopathological analysis and investigation of apoptosis, respectively. In addition, the protein expression of caspase-3, p38 mitogen-activated protein kinase (MAPK) and phosphorylated-p38 MAPK in the cortex were measured by western blotting analysis. These results demonstrated that H₂ significantly reduced the number of apoptotic cells, and the protein expression of p38 MAPK and caspase-3, compared with the IR group. These effects may be associated with the p38MAPK signaling pathway.