Avenanthramide C Prevents Neuronal Apoptosis via PI3K/Akt/GSK3β Signaling Pathway Following Middle Cerebral Artery Occlusion

PI3K/AKT pathway: A potential therapeutic target in cerebral ischemia-reperfusion injury

Cerebral ischemia is a prevalent cerebrovascular disorder, with the restoration of blocked blood vessels serving as the current standard clinical treatment. However, reperfusion can exacerbate neuronal damage and neurological dysfunction, resulting in cerebral ischemia-reperfusion (I/R) injury. Presently, clinical treatment strategies for cerebral I/R injury are limited, creating an urgent need to identify new effective therapeutic targets. The PI3K/AKT signaling pathway, a pro-survival pathway associated with cerebral I/R injury, has garnered significant attention. We conducted a comprehensive review of the literature on the PI3K/AKT pathway in the context of cerebral I/R. Our findings indicate that activation of the PI3K/AKT signaling pathway following cerebral I/R can alleviate oxidative stress, reduce endoplasmic reticulum stress (ERS), inhibit inflammatory responses, decrease neuronal apoptosis, autophagy, and pyroptosis, mitigate blood-brain barrier (BBB) damage, and promote neurological function recovery. Consequently, this pathway ultimately reduces neuronal death, alleviates brain tissue damage, decreases the volume of cerebral infarction, and improves behavioral impairments. These results suggest that the PI3K/AKT signaling pathway is a promising therapeutic target for further research and drug development, holding significant potential for the treatment of cerebral I/R injury.

YTHDF2-regulated matrilin-3 mitigates post-reperfusion hemorrhagic transformation in ischemic stroke via the PI3K/AKT pathway

Hemorrhagic transformation can complicate ischemic strokes after recanalization treatment within a time window that requires early intervention. To determine potential therapeutic effects of matrilin-3, rat cerebral ischemia-reperfusion was produced using transient middle cerebral artery occlusion (tMCAO); intracranial hemorrhage and infarct volumes were assayed through hemoglobin determination and 2,3,5-triphenyltetrazoliumchloride (TTC) staining, respectively. Oxygen-glucose deprivation (OGD) modeling of ischemia was performed on C8-D1A cells. Interactions between matrilin-3 and YTH N6-methyladenosine RNA binding protein F2 (YTHDF2) were determined using RNA immunoprecipitation assay and actinomycin D treatment. Reperfusion after tMCAO modeling increased hemorrhage, hemoglobin content, and infarct volumes; these were alleviated by matrilin treatment. Matrilin-3 was expressed at low levels and YTHDF2 was expressed at high levels in ischemic brains. In OGD-induced cells, matrilin-3 was negatively regulated by YTHDF2. Matrilin-3 overexpression downregulated p-PI3K/PI3K, p-AKT/AKT, ZO-1, VE-cadherin and occludin, and upregulated p-JNK/JNK in ischemic rat brains; these effects were reversed by LY294002 (a PI3K inhibitor). YTHDF2 knockdown inactivated the PI3K/AKT pathway, inhibited inflammation and decreased blood-brain barrier-related protein levels in cells; these effects were reversed by matrilin-3 deficiency. These results indicate that YTHDF2-regulated matrilin-3 protected ischemic rats against post-reperfusion hemorrhagic transformation via the PI3K/AKT pathway and that matrilin may have therapeutic potential in ischemic stroke.

Neurovascular protection of alisol A on cerebral ischemia mice through activating the AKT/GSK3β pathway

Alisol A, a triterpene isolated from Alisma Orientale, has been shown to exhibit anti-inflammatory effects and vascular protection. This study was designed to observe the effect of alisol A on cerebral ischemia (CI)-induced neurovascular dysfunction in the hippocampus and to further explore the potential mechanisms. The results showed that alisol A treatment improved the neurological deficits and cognitive impairment of CI mice. Alisol A reduced gliosis and improved neuronal/glial metabolism. Accordingly, alisol A inhibited inflammatory factors IL-6 and IL-1β induced by overactivation of astrocytes and microglia, thus protecting the neurovasculature. Furthermore, alisol A promoted the survival of neurons by decreasing the ratio of Bax/Bcl-2, and protected brain microvascular endothelial cells (BMECs) by upregulating the expression of ZO-1, Occludin and CD31. The phosphorylation of protein kinase B (AKT) and glycogen synthase kinase 3β (GSK3β) increased after treatment with alisol A. To explore the underlying mechanism, AKT was inhibited. As expected, the neurovascular protection of alisol A above was eliminated by AKT inhibition. The present study primarily suggested that alisol A could exert neurovascular protection in the hippocampus of CI mice by activating the AKT/GSK3β pathway and may potentially be used for the treatment of CI.

Overview on the Polyphenol Avenanthramide in Oats (Avena sativa Linn.) as Regulators of PI3K Signaling in the Management of Neurodegenerative Diseases

Avenanthramides (Avns) and their derivatives, a group of polyphenolic compounds found abundantly in oats (Avena sativa Linn.), have emerged as promising candidates for neuroprotection due to their immense antioxidant, anti-inflammatory, and anti-apoptotic properties. Neurodegenerative diseases (NDDs), characterized by the progressive degeneration of neurons, present a significant global health burden with limited therapeutic options. The phosphoinositide 3-kinase (PI3K) signaling pathway plays a crucial role in cell survival, growth, and metabolism, making it an attractive target for therapeutic intervention. The dysregulation of PI3K signaling has been implicated in the pathogenesis of various NDDs including Alzheimer's and Parkinson's disease. Avns have been shown to modulate PI3K/AKT signaling, leading to increased neuronal survival, reduced oxidative stress, and improved cognitive function. This review explores the potential of Avn polyphenols as modulators of the PI3K signaling pathway, focusing on their beneficial effects against NDDs. Further, we outline the need for clinical exploration to elucidate the specific mechanisms of Avn action on the PI3K/AKT pathway and its potential interactions with other signaling cascades involved in neurodegeneration. Based on the available literature, using relevant keywords from Google Scholar, PubMed, Scopus, Science Direct, and Web of Science, our review emphasizes the potential of using Avns as a therapeutic strategy for NDDs and warrants further investigation and clinical exploration.

Anti-apoptosis effect of traditional Chinese medicine in the treatment of cerebral ischemia-reperfusion injury

Cerebral ischemia, one of the leading causes of neurological dysfunction of brain cells, muscle dysfunction, and death, brings great harm and challenges to individual health, families, and society. Blood flow disruption causes decreased glucose and oxygen, insufficient to maintain normal brain tissue metabolism, resulting in intracellular calcium overload, oxidative stress, neurotoxicity of excitatory amino acids, and inflammation, ultimately leading to neuronal cell necrosis, apoptosis, or neurological abnormalities. This paper summarizes the specific mechanism of cell injury that apoptosis triggered by reperfusion after cerebral ischemia, the related proteins involved in apoptosis, and the experimental progress of herbal medicine treatment through searching, analyzing, and summarizing the PubMed and Web Of Science databases, which includes active ingredients of herbal medicine, prescriptions, Chinese patent medicines, and herbal extracts, providing a new target or new strategy for drug treatment, and providing a reference for future experimental directions and using them to develop suitable small molecule drugs for clinical application. With the research of anti-apoptosis as the core, it is important to find highly effective, low toxicity, safe and cheap compounds from natural plants and animals with abundant resources to prevent and treat Cerebral ischemia/reperfusion (I/R) injury (CIR) and solve human suffering. In addition, understanding and summarizing the apoptotic mechanism of cerebral ischemia-reperfusion injury, the microscopic mechanism of CIR treatment, and the cellular pathways involved will help to develop new drugs.

Therapeutic targets by traditional Chinese medicine for ischemia-reperfusion injury induced apoptosis on cardiovascular and cerebrovascular diseases

Traditional Chinese medicine (TCM) has a significant role in treating and preventing human diseases. Ischemic heart and cerebrovascular injuries are two types of diseases with different clinical manifestations with high prevalence and incidence. In recent years, it has been reported that many TCM has beneficial effects on ischemic diseases through the inhibition of apoptosis, which is the key target to treat myocardial and cerebral ischemia. This review provides a comprehensive summary of the mechanisms of various TCMs in treating ischemic cardiovascular and cerebrovascular diseases through anti-apoptotic targets and pathways. However, clinical investigations into elucidating the pharmacodynamic ingredients of TCM are still lacking, which should be further demystified in the future. Overall, the inhibition of apoptosis by TCM may be an effective strategy for treating ischemic cardio-cerebrovascular diseases.

Extracts of Ginkgo flavonoids and ginkgolides improve cerebral ischaemia-reperfusion injury through the PI3K/Akt/Nrf2 signalling pathway and multicomponent in vivo processes

BACKGROUND

Cerebral ischaemia-reperfusion injury (CIRI) is a common disease characterized by severe attacks and a high disabling rate worldwide. Oxidative stress injury has been proposed as a major risk factor for CIRI. Ginkgo biloba extract (GBE) has been shown to elicit vascular protective effects, the main components of which are Ginkgo flavonoids (GF) and ginkgolides (GL). Our previous study showed that GF and GL played a central role in protecting CIRI, but the mechanism remains unclear. This study aimed to further reveal the protective effect mechanism of GF and GL in rats with CIRI.

METHODS

The antioxidant activity in vitro was assessed by the DPPH method. The model used in this study was established by middle cerebral artery occlusion (MCAO) and reperfusion; the level of CIRI was assessed by nerve function score and TTC staining; we measured the oxidative stress indices in the brain cortex, including LDH, GSH-Px, and the protein contents of Akt, p-Akt, Nrf2, and HO-1; HPLC-MS was used to detect drug concentrations in rat plasma at different times after administration of GF and GL; and the pharmacokinetic parameters of each component were calculated by Drug and Statistic Version 3.2.6 (DAS 3.2.6) software and SPSS 17.0.

RESULTS

Regarding the DPPH free radical scavenging ability, GF performed better free radical scavenging ability than GL. In terms of the nerve function score and TTC staining, there were no statistically significant differences among the GF, GL and combined groups; however, there were significant differences in reducing the activity of LDH and increasing the activity of GSH-Px in the three administration groups. For the expression of Akt, p-Akt, Nrf2, and HO-1, the combined group had a significant effect compared with that in the GF or GL group. In addition, there was a significant multicomponent interaction in vivo in the combined group compared with the GF or GL group.

CONCLUSION

After GF and GL were used in combination, the effect of anti-CIRI was more pronounced. This result indicated that GF and GL might improve CIRI by activating the PI3K/Akt/Nrf2 signalling pathway and promoting multicomponent interactions in vivo.

AKT/GSK-3β signaling is altered through downregulation of mTOR during cerebral Ischemia/Reperfusion injury

PURPOSE

Cellular responses following cerebral ischemia/reperfusion injury are critical to recovery and survival after ischemic stroke. Understanding of these cellular responses can help the design of therapies to protect brain tissue and promote recovery after stroke. One of these cellular responses may be mediated by the AKT (protein kinase B) signal transduction pathway. This study was aimed to investigate the cerebral ischemia-induced alterations of AKT signaling and the upstream molecular pathways.

METHODS

We modeled cerebral ischemia by middle cerebral artery occlusion in 2-3-month-old male C57BL/6J mice and then analyze the brain samples by using quantitative Western blots and phosphorylation/activation-dependent kinase antibodies. Cerebral ischemia was confirmed by staining of brain slices with 1% 2,3,5-triphenyltetrazolium chloride (TTC) and Nissl, as well as neurological assessments of the mice 24 h after ischemia-reperfusion surgery.

RESULTS

We found marked downregulation of AKT within 12 h of cerebral ischemia/reperfusion, which leads to overactivation of glycogen synthase kinase-3β (GSK-3β). Furthermore, we found that the downregulation of AKT was mediated by downregulation of mTORC2 (the complex 2 of the mechanistic target of rapamycin) instead of its common upstream kinases, phosphatidylinositol 3-kinase and phosphoinositide-dependent kinase-1.

CONCLUSION

Our findings provide new insight into the cellular responses to ischemia/reperfusion brain injury and will help develop new treatments targeting the AKT signaling pathway for the treatment of ischemic stroke.

Avenanthramide C from Oats Protects Pyroptosis through Dependent ROS-Induced Mitochondrial Damage by PI3K Ubiquitination and Phosphorylation in Pediatric Pneumonia

Oat containing rich β-glucan, polyphenols, flavonoids, saponins, alkaloids, and other substances shows good biological activities. Therefore, the present study aimed to uncover the possible mechanism and therapeutic effect of Avenanthramide C in lessening inflammatory responses in pediatric pneumonia. Pediatric pneumonia was induced by liposaccharide (LPS) for vivo model and vitro model. Macrophage was performed to determine the mechanism and effects of Avenanthramide C in pediatric pneumonia. NLRP3 activity participated in the effects of Avenanthramide C in pediatric pneumonia. Avenanthramide C induced p-PI3K and p-Akt expressions and reduced ubiquitination of PI3K expression in pediatric pneumonia. On the other hand, Avenanthramide C integrated serine at 821 sites of the PI3K protein function. Avenanthramide C reduced ROS (reactive oxygen species)-induced mitochondrial damage by PI3K/AKT function in a model of pediatric pneumonia. Avenanthramide C protects pyroptosis in a model of pediatric pneumonia by PI3K/AKT/Nrf2/ROS signaling. Taken together, our results demonstrated that Avenanthramide C protects pyroptosis through dependent ROS-induced mitochondrial damage by PI3K ubiquitination and phosphorylation in a model of pediatric pneumonia, suggesting its potential use for the treatment of pediatric pneumonia and other inflammatory diseases.

Tideglusib Ameliorates Ischemia/Reperfusion Damage by Inhibiting GSK-3β and Apoptosis in Rat Model of Ischemic Stroke

OBJECTIVES

Glycogen synthase kinase-3β (GSK-3β), a serine/threonine protein kinase, gets activated and worsen stroke outcome after ischemia/reperfusion (I/R) injury by inducing inflammation and apoptosis. In this study, tideglusib, a selective irreversible and non-ATP competitive inhibitor of GSK-3β, was explored in cerebral I/R damage using middle cerebral artery occlusion (MCAo) model in rats.

MATERIALS AND METHODS

MCAo was done for 90 min in male Wistar rats (250-280 g) using doccol suture. In pre-treatment group, tideglusib (50 mg/kg) was administered once daily for 2 days and on the day of surgery, 30 min before MCAo. Next day, rats were examined for neurobehavioral parameters and MRI was performed to assess brain damage. In post-treatment group, tideglusib was started at 30 min after MCAo and continued for the next 2 days. After 72 h of MCAo, behavioral parameters and brain damage by MRI were assessed. Further, oxidative stress markers (MDA and GSH), inflammatory cytokines (TNF-α, IL-1β and IL-10) and expression levels of pGSK-3β S9, Bcl-2 and Bax were estimated in pre-treatment group.

RESULTS

Tideglusib pre-treatment but not post-treatment significantly improved neurobehavioral parameters (p < 0.05) and reduced brain damage (p < 0.01) when compared with MCAo group. I/R induced changes in MDA (p < 0.01), TNF-α and IL-1β (p < 0.05) were significantly attenuated by pre-treatment. Further, tideglusib pre-treatment ameliorated MCAo induced altered expressions of pGSK-3β S9, Bcl-2 and Bax.

CONCLUSION

The results of our exploratory study indicated prophylactic potential of tideglusib in I/R injury by modulating pGSK-3β S9, apoptosis and neuro-inflammation.

The Progress of Nomenclature, Structure, Metabolism, and Bioactivities of Oat Novel Phytochemical: Avenanthramides

Oats are among the most commonly consumed whole grains and are widely grown worldwide, and they contain numerous nutrients, including proteins, lipids, vitamins, minerals, β-glucan, and unique phytochemical polyphenol avenanthramides (Avns). Recent studies have indicated that Avns play essential roles in mediating the health benefits of oats. This review systemically summarized the nomenclature and structures of Avns, effect of germination on promoting Avns production, and in vivo metabolites produced after Avns consumption. The classical functions and novel potential bioactivities of Avns were further elucidated. The classical functions of Avns in cancer prevention, antioxidative response, anti-inflammatory reaction, and maintaining muscle health were expounded, and the internal mechanisms of these functions were analyzed. The potential novel bioactivities of Avns in modulating gut microbiota, alleviating obesity, and preventing chronic diseases, such as atherosclerosis and osteoporosis, were further revealed. This review may provide new prospects and directions for the development and utilization of oat Avns.

Natural products attenuate PI3K/Akt/mTOR signaling pathway: A promising strategy in regulating neurodegeneration

BACKGROUND

As common, progressive, and chronic causes of disability and death, neurodegenerative diseases (NDDs) significantly threaten human health, while no effective treatment is available. Given the engagement of multiple dysregulated pathways in neurodegeneration, there is an imperative need to target the axis and provide effective/multi-target agents to tackle neurodegeneration. Recent studies have revealed the role of phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) in some diseases and natural products with therapeutic potentials.

PURPOSE

This is the first systematic and comprehensive review on the role of plant-derived secondary metabolites in managing and/or treating various neuronal disorders via the PI3K/Akt/mTOR signaling pathway.

STUDY DESIGN AND METHODS

A systematic and comprehensive review was done based on the PubMed, Scopus, Web of Science, and Cochrane electronic databases. Two independent investigators followed the PRISMA guidelines and included papers on PI3K/Akt/mTOR and interconnected pathways/mediators targeted by phytochemicals in NDDs.

RESULTS

Natural products are multi-target agents with diverse pharmacological and biological activities and rich sources for discovering and developing novel therapeutic agents. Accordingly, recent studies have shown increasing phytochemicals in combating Alzheimer's disease, aging, Parkinson's disease, brain/spinal cord damages, depression, and other neuronal-associated dysfunctions. Amongst the emerging targets in neurodegeneration, PI3K/Akt/mTOR is of great importance. Therefore, attenuation of these mediators would be a great step towards neuroprotection in such NDDs.

CONCLUSION

The application of plant-derived secondary metabolites in managing and/or treating various neuronal disorders through the PI3K/Akt/mTOR signaling pathway is a promising strategy towards neuroprotection.

Trelagliptin Mitigates Macrophage Infiltration by Preventing the Breakdown of the Blood-Brain Barrier in the Brain of Middle Cerebral Artery Occlusion Mice

Stroke is a significant cardiovascular disease that influences the health of human beings all over the world, especially the elderly population. It is reported that the blood-brain barrier (BBB) can be easily destroyed by stroke, which is one of the main factors responsible for macrophage infiltration and central nervous inflammation. Here, we report the protective effects of Trelagliptin against BBB injury and macrophage infiltration. Our results indicate that the infraction volume, the neurological score, and macrophage infiltration staining with CD68 were increased in middle cerebral artery occlusion (MCAO) mice but significantly reversed by treatment with Trelagliptin. Additionally, Trelagliptin reduced the permeability of the BBB by increasing the expression of the tight junction zonula occludens protein-1 (ZO-1) in the cerebral cortex. In an in vitro hypoxia model of endothelial cells, the increased migration of macrophages, enlarged permeability of endothelial monolayer, downregulation of ZO-1, and elevated expression level of CXCL1 by hypoxic conditions were all reversed by treatment with Trelagliptin in a dose-dependent manner. Our results demonstrate that Trelagliptin might mitigate macrophage infiltration by preventing the breakdown of the blood-brain barrier in the brains of MCAO mice.

Neuroprotective Effect of Kinase Inhibition in Ischemic Factor Modeling In Vitro

The contribution of many neuronal kinases to the adaptation of nerve cells to ischemic damage and their effect on functional neural network activity has not yet been studied. The aim of this work is to study the role of the four kinases belonging to different metabolic cascades (SRC, Ikkb, eEF2K, and FLT4) in the adaptive potential of the neuron-glial network for modeling the key factors of ischemic damage. We carried out a comprehensive study on the effects of kinases blockade on the viability and network functional calcium activity of nerve cells under ischemic factor modeling in vitro. Ischemic factor modelling was performed on day 14 of culturing primary hippocampal cells obtained from mouse embryos (E18). The most significant neuroprotective effect was shown in the blockade of FLT4 kinase in the simulation of hypoxia. The studies performed revealed the role of FLT4 in the development of functional dysfunction in cerebrovascular accidents and created new opportunities for the study of this enzyme and its blockers in the formation of new therapeutic strategies.