XQ-1H promotes cerebral angiogenesis via activating PI3K/Akt/GSK3β/β-catenin/VEGF signal in mice exposed to cerebral ischemic injury

Endothelial β-catenin upregulation and Y142 phosphorylation drive diabetic angiogenesis via upregulating KDR/HDAC9

BACKGROUND

Diabetic angiogenesis is closely associated with disabilities and death caused by diabetic microvascular complications. Advanced glycation end products (AGEs) are abnormally accumulated in diabetic patients and are a key pathogenic factor for diabetic angiogenesis. The present study focuses on understanding the mechanisms underlying diabetic angiogenesis and identifying therapeutic targets based on these mechanisms.

METHODS

In this study, AGE-induced angiogenesis serves as a model to investigate the mechanisms underlying diabetic angiogensis. Mouse aortic rings, matrigel plugs, and HUVECs or 293T cells were employed as research objects to explore this pathological process by using transcriptomics, gene promoter reporter assays, virtual screening and so on.

RESULTS

Here, we found that AGEs activated Wnt/β-catenin signaling pathway and enhanced the β-catenin protein level by affecting the expression of β-catenin degradation-related genes, such as FZDs (Frizzled receptors), LRPs (LDL Receptor Related Proteins), and AXIN1. AGEs could also mediate β-catenin Y142 phosphorylation through VEGFR1 isoform5. These dual effects of AGEs elevated the nuclear translocation of β-catenin and sequentially induced the expression of KDR (Kinase Insert Domain Receptor) and HDAC9 (Histone Deacetylase 9) by POU5F1 and NANOG, respectively, thus mediating angiogenesis. Finally, through virtual screening, Bioymifi, an inhibitor that blocks VEGFR1 isoform5-β-catenin complex interaction and alleviates AGE-induced angiogenesis, was identified.

CONCLUSION

Collectively, this study offers insight into the pathophysiological functions of β-catenin in diabetic angiogenesis.

Wnt signalling pathways as mediators of neuroprotective mechanisms: therapeutic implications in stroke

A stroke is a complicated neurological illness that occurs when there is a disruption in the blood flow to the brain. This disruption results in the damage of neurons, which then leads to functional abnormalities. The Wnt signalling pathway, which is already well-known for its important function in development and tissue homeostasis, has recently been recognised as a critical factor in the pathophysiology of stroke. Recent studies have shown the Wnt pathway's roles in stroke-related events. The complex-interactions between the Wnt pathway and stroke emphasising the pathway's contributions to neuro-protection and synaptic plasticity. The Wnt pathway's influence on neuro-genesis and synaptic plasticity underscores its potential for driving stroke recovery and rehabilitation strategies. The current review discusses about the Wnt signalling pathway in brain pathophysiology and stroke with special emphasis on the various pathways involved in the positive and negative modulation of Wnt pathway namely Phosphoinositide 3-kinase (PI3-K), Glycogen synthase kinase-3β (GSK-3β), Mitogen-activated protein kinase (MAPK) and nuclear factor erythroid 2-related factor 2 (Nrf2) pathway.

Role of ATG7-dependent non-autophagic pathway in angiogenesis

ATG7, one of the core proteins of autophagy, plays an important role in various biological processes, including the regulation of autophagy. While clear that autophagy drives angiogenesis, the role of ATG7 in angiogenesis remains less defined. Several studies have linked ATG7 with angiogenesis, which has long been underappreciated. The knockdown of ATG7 gene in cerebrovascular development leads to angiogenesis defects. In addition, specific knockout of ATG7 in endothelial cells results in abnormal development of neovascularization. Notably, the autophagy pathway is not necessary for ATG7 regulation of angiogenesis, while the ATG7-dependent non-autophagic pathway plays a critical role in the regulation of neovascularization. In order to gain a better understanding of the non-autophagic pathway-mediated biological functions of the autophagy-associated protein ATG7 and to bring attention to this expanding but understudied research area, this article reviews recent developments in the ATG7-dependent non-autophagic pathways regulating angiogenesis.

Ischemia-reperfusion injury: molecular mechanisms and therapeutic targets

Ischemia-reperfusion (I/R) injury paradoxically occurs during reperfusion following ischemia, exacerbating the initial tissue damage. The limited understanding of the intricate mechanisms underlying I/R injury hinders the development of effective therapeutic interventions. The Wnt signaling pathway exhibits extensive crosstalk with various other pathways, forming a network system of signaling pathways involved in I/R injury. This review article elucidates the underlying mechanisms involved in Wnt signaling, as well as the complex interplay between Wnt and other pathways, including Notch, phosphatidylinositol 3-kinase/protein kinase B, transforming growth factor-β, nuclear factor kappa, bone morphogenetic protein, N-methyl-D-aspartic acid receptor-Ca2+-Activin A, Hippo-Yes-associated protein, toll-like receptor 4/toll-interleukine-1 receptor domain-containing adapter-inducing interferon-β, and hepatocyte growth factor/mesenchymal-epithelial transition factor. In particular, we delve into their respective contributions to key pathological processes, including apoptosis, the inflammatory response, oxidative stress, extracellular matrix remodeling, angiogenesis, cell hypertrophy, fibrosis, ferroptosis, neurogenesis, and blood-brain barrier damage during I/R injury. Our comprehensive analysis of the mechanisms involved in Wnt signaling during I/R reveals that activation of the canonical Wnt pathway promotes organ recovery, while activation of the non-canonical Wnt pathways exacerbates injury. Moreover, we explore novel therapeutic approaches based on these mechanistic findings, incorporating evidence from animal experiments, current standards, and clinical trials. The objective of this review is to provide deeper insights into the roles of Wnt and its crosstalk signaling pathways in I/R-mediated processes and organ dysfunction, to facilitate the development of innovative therapeutic agents for I/R injury.

Impaired cerebral microvascular endothelial cells integrity due to elevated dopamine in myasthenic model

Myasthenia gravis is an autoimmune disease characterized by pathogenic antibodies that target structures of the neuromuscular junction. However, some patients also experience autonomic dysfunction, anxiety, depression, and other neurological symptoms, suggesting the complex nature of the neurological manifestations. With the aim of explaining the symptoms related to the central nervous system, we utilized a rat model to investigate the impact of dopamine signaling in the central nervous and peripheral circulation. We adopted several screening methods, including western blot, quantitative PCR, mass spectrum technique, immunohistochemistry, immunofluorescence staining, and flow cytometry. In this study, we observed increased and activated dopamine signaling in both the central nervous system and peripheral circulation of myasthenia gravis rats. Furthermore, changes in the expression of two key molecules, Claudin5 and CD31, in endothelial cells of the blood-brain barrier were also examined in these rats. We also confirmed that dopamine incubation reduced the expression of ZO1, Claudin5, and CD31 in endothelial cells by inhibiting the Wnt/β-catenin signaling pathway. Overall, this study provides novel evidence suggesting that pathologically elevated dopamine in both the central nervous and peripheral circulation of myasthenia gravis rats impair brain-blood barrier integrity by inhibiting junction protein expression in brain microvascular endothelial cells through the Wnt/β-catenin pathway.

Anti-atherosclerotic effects and molecular targets of ginkgolide B from Ginkgo biloba

Bioactive compounds derived from herbal medicinal plants modulate various therapeutic targets and signaling pathways associated with cardiovascular diseases (CVDs), the world's primary cause of death. Ginkgo biloba , a well-known traditional Chinese medicine with notable cardiovascular actions, has been used as a cardio- and cerebrovascular therapeutic drug and nutraceutical in Asian countries for centuries. Preclinical studies have shown that ginkgolide B, a bioactive component in Ginkgo biloba , can ameliorate atherosclerosis in cultured vascular cells and disease models. Of clinical relevance, several clinical trials are ongoing or being completed to examine the efficacy and safety of ginkgolide B-related drug preparations in the prevention of cerebrovascular diseases, such as ischemia stroke. Here, we present a comprehensive review of the pharmacological activities, pharmacokinetic characteristics, and mechanisms of action of ginkgolide B in atherosclerosis prevention and therapy. We highlight new molecular targets of ginkgolide B, including nicotinamide adenine dinucleotide phosphate oxidases (NADPH oxidase), lectin-like oxidized LDL receptor-1 (LOX-1), sirtuin 1 (SIRT1), platelet-activating factor (PAF), proprotein convertase subtilisin/kexin type 9 (PCSK9) and others. Finally, we provide an overview and discussion of the therapeutic potential of ginkgolide B and highlight the future perspective of developing ginkgolide B as an effective therapeutic agent for treating atherosclerosis.

Ginkgo biloba Extract Drives Gut Flora and Microbial Metabolism Variation in a Mouse Model of Alzheimer's Disease

Alzheimer's disease (AD) is a complex neurodegenerative disease. Numerous investigations have demonstrated that medications that regulate the "brain-gut" axis can ameliorate disease symptoms of AD. Studies have shown that Ginkgo biloba extract (EGb) is involved in intestinal metabolism to meet the goal of illness treatment. EGb is currently utilized extensively in the clinical prevention and treatment of cardiovascular and cerebrovascular diseases. However, the regulatory effect of EGb on intestinal flora and its metabolites in AD pathology remains largely speculative. In this study, the Morris water maze test showed a significant improvement of spatial memory in the AD mouse model (APP/PS1 mice) after EGb treatment. We next confirmed the positive effects of EGb on the gut flora and metabolites of APP/PS1 mice and further showed that EGb treatment reshaped the disturbed gut microbiome, in particular by reducing the Firmicutes/Bacteroides ratio and increasing the abundance of Bacteroidetes, Uroviricota, Streptophyta, and Spirochaetes. Meanwhile, a non-targeted metabolomics analysis showed that EGb treatment significantly reversed the dysfunction of the microbial metabolic phenotype by altering Limosilactobacillus and Parvibacte, with 300 differential metabolites modulated (131 up-regulated, 169 down-regulated). Our findings highlight the significant regulatory impact of EGb on intestinal microflora and microbial metabolism in AD mice models and provide a potential therapeutic strategy for AD.

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.

Overexpression of FSP1 Ameliorates ferroptosis via PI3K/ AKT /GSK3β pathway in PC12 cells with Oxygen-Glucose Deprivation/Reoxygenation

After ischemia and reperfusion (I/R), nerve cell damage is a pathogenic process that involves numerous molecular processes. In the last ten years, one new classification of programmed cell death is ferroptosis. More recent research has demonstrated that ferroptosis has a role in a variety of neurological disorders, including stroke, cancer, and neurodegenerative illnesses. Ferroptosis suppressor protein 1 (FSP1) plays a significant role in inhibiting ferroptosis. The purpose of this work is to determine how overexpression of FSP1 affects the ferroptosis of PC12 cells under the condition of oxygen-glucose deprivation/reoxygenation (OGD/R). The expression of FSP1 was regulated by lentivirus transfection technology. Western blot and immunofluorescence were used to measure protein levels related to ferroptosis and the PI3K/AKT/GSK3β signal pathway. Determine cell viability using the appropriate kit. Mitochondrial structural morphology was checked by transmission electron microscopy in PC12 cells. Reactive oxygen species (ROS) and Malondialdehyde (MDA) were quantified using the relevant kits. OGD/R induced ferroptosis in PC12 cells, however, FSP1 overexpression reverses ferroptosis and promotes cell viability, lowering ROS and MDA content. The expression of FSP1 decreased in OGD/R0h and OGD/R6h and rebounded in OGD/R24h and OGD/R48h. During the processes of OGD/R-induced ferroptosis, FSP1 overexpression significantly stimulated PI3K/AKT/GSK3β pathway, but LY294002 weakens the protective effect of FSP1 overexpression. Our outcomes demonstrate that overexpression of FSP1 markedly enhances the ability to resist ferroptosis via the PI3K/AKT/GSK3β pathway. The above results may provide a new preliminary lead for the treatment of the cerebral ischemia-reperfusion injury.

Cerebrospinal fluid-derived extracellular vesicles after spinal cord injury promote vascular regeneration via PI3K/AKT signaling pathway

Background

The cerebrospinal fluid (CSF), which surrounds the brain and spinal cord, is predominantly produced by the choroid plexus of the ventricle. Although CSF-derived extracellular vesicles (CSF-EVs) may be utilized as diagnostic and prognostic indicators for illnesses of the central nervous system (CNS), it is uncertain if CSF-EVs may have an impact on neurological function after spinal cord injury (SCI).

Methods

Here, we isolated EVs using ultracentrifugation after extracting CSF from Bama miniature pigs. We then combined CSF-EVs with hydrogel and put it on the spinal cord's surface. To determine if CSF-EVs had an impact on mice's neurofunctional recovery, behavioral evaluations were employed. Both in vitro and in vivo, the effect of CSF-EVs on angiogenesis was assessed. We investigated whether CSF-EVs stimulated the PI3K/AKT pathway to alter angiogenesis using the PI3K inhibitor LY294002.

Results

CSF-EVs were successfully isolated and identified by transmission electron microscope (TEM), nano-tracking analysis (NTA), and western blot. CSF-EVs could be ingested by vascular endothelial cells as proved by in vivo imaging and immunofluorescence. We demonstrated that CSF-EVs derived from pigs with SCI (SCI-EVs) showed a better effect on promoting vascular regeneration as compared to CSF-EVs isolated from pigs receiving laminectomy (Sham-EVs). Behavioral assessments demonstrated that SCI-EVs could dramatically enhance motor and sensory function in mice with SCI. Western blot analysis suggested that SCI-EVs promote angiogenesis by activating PI3K/AKT signaling pathway, and the pro-angiogenetic effect of SCI-EVs was attenuated by the application of the LY294002 (PI3K inhibitor).

Conclusion

Our study revealed that CSF-EVs could enhance vascular regeneration by activating the PI3K/AKT pathway, hence improving motor function recovery after SCI, which may offer potential novel therapeutic options for acute SCI.

The translational potential of this article

This study demonstrated the promotion of vascular regeneration and neurological function of CSF-derived exosomes, which may provide a potential therapeutic approach for the treatment of spinal cord injury.

Ferrostatin-1 alleviates cerebral ischemia/reperfusion injury through activation of the AKT/GSK3β signaling pathway

Ischemic stroke is the major cause of disability and death worldwide, but post-stroke neuronal death and related mechanisms remain unclear. Ferroptosis, a newly identified type of regulated cell death, has been shown to be associated with neurological disorders, yet the exact relationship between ferroptosis and ischemic stroke has not been elucidated. The purpose of this study is to investigate the effects of ferroptosis-specific inhibitor ferrostatin-1 (Fer-1) on neuronal injury after cerebral ischemia/reperfusion (I/R) and the underlying mechanism. In this study, we demonstrated that ferroptosis does occur in the stroke model. We found that Fer-1 reduced the levels of iron and malondialdehyde, and increased the content of glutathione and the expression of solute carrier family 7 member 11 and glutathione peroxidase 4 in cerebral I/R models. Additionally, Fer-1 significantly reduced the infarct volume and improved neurobehavioral outcomes. Moreover, we found that Fer-1 increased the levels of phosphorylated AKT and GSK3β following cerebral I/R. To further investigate the functional role of the AKT in the neuroprotective effects of Fer-1, MCAO models and oxygen-glucose deprivation-induced HT22 cells were pretreated with the AKT inhibitor MK-2206 before treatment with Fer-1 and the protective effects of Fer-1 were reversed. In conclusion, Fer-1 has protective effects on cerebral I/R injury by activating the AKT/GSK3β pathway, indicating that ferroptosis may become a novel target in the treatment of ischemic stroke.

Exosomes in pathogenesis, diagnosis, and therapy of ischemic stroke

Ischemic stroke is one of the major contributors to death and disability worldwide. Thus, there is an urgent need to develop early brain tissue perfusion therapies following acute stroke and to enhance functional recovery in stroke survivors. The morbidity, therapy, and recovery processes are highly orchestrated interactions involving the brain with other tissues. Exosomes are natural and ideal mediators of intercellular information transfer and recognized as biomarkers for disease diagnosis and prognosis. Changes in exosome contents express throughout the physiological process. Accumulating evidence demonstrates the use of exosomes in exploring unknown cellular and molecular mechanisms of intercellular communication and organ homeostasis and indicates their potential role in ischemic stroke. Inspired by the unique properties of exosomes, this review focuses on the communication, diagnosis, and therapeutic role of various derived exosomes, and their development and challenges for the treatment of cerebral ischemic stroke.

A New Therapeutic Trend: Natural Medicine for Ameliorating Ischemic Stroke via PI3K/Akt Signaling Pathway

Ischemic stroke (IS) is an acute cerebrovascular disease caused by sudden arterial occlusion, which is characterized by a high morbidity, mortality, and disability rate. It is one of the most important causes of nervous system morbidity and mortality in the world. In recent years, the search for new medicine for the treatment of IS has become an attractive research focus. Due to the extremely limited time window of traditional medicine treatment, some side effects may occur, and accompanied by the occurrence of adverse reactions, the frequency of exploration with natural medicine is significantly increased. Phosphatidylinositol-3-kinase/Protein kinase B (PI3K/Akt) signaling pathway is a classical pathway for cell metabolism, growth, apoptosis, and other physiological activities. There is considerable research on medicine that treats various diseases through this pathway. This review focuses on how natural medicines (including herbs and insects) regulate important pathophysiological processes such as inflammation, oxidative stress, apoptosis, and autophagy through the PI3K/Akt signaling pathway, and the role it plays in improving IS. We found that many kinds of herbal medicine and insect medicine can alleviate the damage caused by IS through the PI3K/Akt signaling pathway. Moreover, the prescription after their combination can also achieve certain results. Therefore, this review provides a new candidate category for medicine development in the treatment of IS.

Terpenoid natural products exert neuroprotection via the PI3K/Akt pathway

PI3K/Akt, an essential signaling pathway widely present in cells, has been shown to be relevant to neurological disorders. As an important class of natural products, terpenoids exist in large numbers and have diverse backbones, so they have a great chance to be identified as neuroprotective agents. In this review, we described and summarized recent research for a range of terpenoid natural products associated with the PI3K/Akt pathway by classifying their basic chemical structures of the terpenes, identified by electronic searches on PubMed, Web of Science for research, and Google Scholar websites. Only articles published in English were included. Our discussion here concerned 16 natural terpenoids and their mechanisms of action, the associated diseases, and the methods of experimentation used. We also reviewed the discovery of their chemical structures and their derivatives, and some compounds have been concluded for their structure–activity relationships (SAR). As a result, terpenoids are excellent candidates for research as natural neuroprotective agents, and our content will provide a stepping stone for further research into these natural products. It may be possible for more terpenoids to serve as neuroprotective agents in the future.

Exosomes Derived From Mesenchymal Stem Cells Pretreated With Ischemic Rat Heart Extracts Promote Angiogenesis via the Delivery of DMBT1

Mesenchymal stem cell-derived exosomes (MSC-Exos) have been shown to promote angiogenesis. Treating MSCs with ischemic rat brain extracts was sufficient to augment their benefits in stroke. However, no similar analyses of ischemic heart extracts have been performed to date. We aim to determine whether MSC-Exos derived from MSCs pretreated with ischemic rat heart extract were able to promote angiogenesis and to clarify underlying mechanisms. ELISA (enzyme-linked immunosorbent assay) of heart extracts revealed a significant increase of vascular endothelial growth factor (VEGF) at 24 h post-MI (myocardial infarction) modeling, and time-dependent decreases in hypoxia inducible factor-1α (HIF-1α). MTT and wound healing assays revealed human umbilical vein endothelial cells (HUVECs) migration and proliferation increased following MSCE-Exo treatment (exosomes derived from MSC pretreated with ischemic heart extracts of 24 h post-MI) relative to MSCN-Exo treatment (exosomes derived from MSC pretreated with normal heart extracts). Proteomic analyses of MSCE-Exo and MSCN-Exo were conducted to screen for cargo proteins promoting angiogenesis. Result revealed several angiogenesis-related proteins were upregulated in MSCE-Exo, including DMBT1 (deleted in malignant brain tumors 1). When DMBT1 was silenced in MSCs, HUVECs with MSCDMBT1 RNAi-Exo treatment exhibited impaired proliferative and migratory activity and reductions of DMBT1, p-Akt, β-catenin, and VEGF. To explore how ischemic heart extracts took effects, ELISA was conducted showing a significant increase of IL-22 at 24 h post-MI modeling. P-STAT3, IL22RA1, DMBT1, and VEGF proteins were increased in MSCE relative to MSCN, and VEGF and DMBT1 were increased in MSCE-Exos. Together, these suggest that IL-22 upregulation in ischemic heart extracts can increase DMBT1 in MSCs. Exosomes derived from those MSCs deliver DMBT1 to HUVECs, thereby enhancing their migratory and proliferative activity.