Neuroprotection of benzoinum in cerebral ischemia model rats via the ACE-AngI-VEGF pathway

The potential role of brain renin-angiotensin system in the neuropathology of Parkinson disease: Friend, foe or turncoat?

Parkinson disease (PD) is one of the most common neurodegenerative diseases of the brain. Of note, brain renin-angiotensin system (RAS) is intricate in the PD neuropathology through modulation of oxidative stress, mitochondrial dysfunction and neuroinflammation. Therefore, modulation of brain RAS by angiotensin receptor blockers (ARBs) and angiotensin-converting enzyme inhibitors (ACEIs) may be effective in reducing the risk and PD neuropathology. It has been shown that all components including the peptides and enzymes of the RAS are present in the different brain areas. Brain RAS plays a critical role in the regulation of memory and cognitive function, and in the controlling of central blood pressure. However, exaggerated brain RAS is implicated in the pathogenesis of different neurodegenerative diseases including PD. Two well-known pathways of brain RAS are recognized including; the classical pathway which is mainly mediated by AngII/AT1R has detrimental effects. Conversely, the non-classical pathway which is mostly mediated by ACE2/Ang1-7/MASR and AngII/AT2R has beneficial effects against PD neuropathology. Exaggerated brain RAS affects the viability of dopaminergic neurons. However, the fundamental mechanism of brain RAS in PD neuropathology was not fully elucidated. Consequently, the purpose of this review is to disclose the mechanistic role of RAS in in the pathogenesis of PD. In addition, we try to revise how the ACEIs and ARBs can be developed for therapeutics in PD.

Role of brain renin-angiotensin system in depression: A new perspective

Depression is a mood disorder characterized by abnormal thoughts. The pathophysiology of depression is related to the deficiency of serotonin (5HT), which is derived from tryptophan (Trp). Mitochondrial dysfunction, oxidative stress, and neuroinflammation are involved in the pathogenesis of depression. Notably, the renin-angiotensin system (RAS) is involved in the pathogenesis of depression, and different findings revealed that angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) may be effective in depression. However, the underlying mechanism for the role of dysregulated brain RAS-induced depression remains speculative. Therefore, this review aimed to revise the conceivable role of ACEIs and ARBs and how these agents ameliorate the pathophysiology of depression. Dysregulation of brain RAS triggers the development and progression of depression through the reduction of brain 5HT and expression of brain-derived neurotrophic factor (BDNF) and the induction of mitochondrial dysfunction, oxidative stress, and neuroinflammation. Therefore, inhibition of central classical RAS by ARBS and ACEIs and activation of non-classical RAS prevent the development of depression by regulating 5HT, BDNF, mitochondrial dysfunction, oxidative stress, and neuroinflammation.

A Novel Hybrid of Telmisartan and Borneol Ameliorates Neuroinflammation and White Matter Injury in Ischemic Stroke Through ATF3/CH25H Axis

Cerebral ischemic stroke causes substantial white matter injury, which is further aggravated by neuroinflammation mediated by microglia/astrocytes. Given the anti-neuroinflammatory action of telmisartan and the enhancing blood-brain barrier (BBB) permeability potential of resuscitation-inducing aromatic herbs, 13 hybrids (3a-m) of telmisartan (or its simplified analogues) with resuscitation-inducing aromatic agents were designed, synthesized, and biologically evaluated. Among them, the optimal compound 3a (the ester hybrid of telmisartan and (+)-borneol) potently inhibited neuroinflammation mediated by microglia/astrocytes and ameliorated ischemic stroke. Particularly, 3a significantly conferred protection for white matter integrity after cerebral ischemic stroke via decreasing abnormally dephosphorylated neurofilament protein, upregulating myelin basic protein, and attenuating oligodendrocyte damage. Further RNA-sequencing data revealed that 3a upregulated expression of transcriptional regulator ATF3 to reduce the expression of CH25H, prevented proinflammatory state of lipid-droplet-accumulating microglia/astrocytes to limit excessive inflammation, and eventually protected neighboring oligodendrocytes to prevent white matter injury. Taken with the desirable pharmacokinetics behavior and improved brain distribution, 3a may be a feasible therapeutic agent for ischemic stroke and other neurological disorders with white matter injury.

Catalpol Alleviates Ischemic Stroke Through Promoting Angiogenesis and Facilitating Proliferation and Differentiation of Neural Stem Cells via the VEGF-A/KDR Pathway

Stroke is one of the leading causes of disability and death globally with a lack of effective therapeutic strategies. Catalpol is a bioactive compound derived from the traditional Chinese medicine Rehmannia glutinosa and it has been shown to be protective against various neurological diseases. The potential roles of catalpol against ischemic stroke are still not completely clear. In this study, we examined the effect and mechanism of catalpol against ischemic stroke using in vivo rat distal middle cerebral artery occlusion (dMCAO) and in vitro oxygen-glucose deprivation (OGD) models. We demonstrated that catalpol indeed attenuated the neurological deficits caused by dMCAO and improved neurological function. Catalpol remarkably promoted angiogenesis, promoted proliferation and differentiation of neural stem cells (NSCs) in the subventricular zone (SVZ), and prevented neuronal loss and astrocyte activation in the ischemic cortex or hippocampal dentate gyrus (DG) in vivo. The vascular endothelial growth factor receptor 2 (KDR, VEGFR-2) inhibitor SU5416 and VEGF-A shRNA were used to investigate the underlying mechanisms. The results showed that SU5416 administration or VEGF-A-shRNA transfection both attenuated the effects of catalpol. We also found that catalpol promoted the proliferation of cultured brain microvascular endothelial cells (BMECs) and the proliferation and differentiation of NSCs subjected to OGD insult in vitro. Interestingly, the impact of catalpol on cultured cells was also inhibited by SU5416. Moreover, catalpol was shown to protect NSCs against OGD indirectly by promoting BMEC proliferation in the co-cultured system. Taken together, catalpol showed therapeutic potential in cerebral ischemia by promoting angiogenesis and NSC proliferation and differentiation. The protective effects of catalpol were mediated through VEGF-A/KDR pathway activation.

Phenformin suppresses angiogenesis through the regulation of exosomal microRNA-1246 and microRNA-205 levels derived from oral squamous cell carcinoma cells

Exosomes secreted by cancer cells are important components in the tumor microenvironment, enabling cancer cells to communicate with each other and with noncancerous cells to play important roles in tumor progression and metastasis. Phenformin, a biguanide antidiabetic drug, has been reported to have a strong antitumor function in multiple types of cancer cells, however little research has been reported about whether phenformin can regulate the secretion of exosomes by cancer cells to regulate the tumor microenvironment and contribute to its antitumor function. Here we found that exosomes (Phen-Exo) derived from phenformin-treated oral squamous cell carcinoma (OSCC) cells significantly suppress the proliferation, migration and tube formation of human umbilical vein endothelial cells (HUVECs) in vitro. The inhibition of angiogenesis by Phen-Exo was verified in vivo by matrigel plug angiogenesis assays and by chick chorioallantoic membrane assays. Mechanistically, we discovered that the expression of microRNA-1246 (miR-1246) and microRNA-205 (miR-205) was significantly increased in exosomes secreted by OSCC cells treated with phenformin, while high expression levels of miR-1246 or miR-205 in vascular endothelial cells inhibited their angiogenic effects and decreased expression of the angiogenic factor VEGFA. In conclusion, these results reveal that phenformin can inhibit angiogenesis by regulating the levels of miR-1246 and miR-205 in exosomes secreted by OSCC cells, suggesting that phenformin has the potential to alter the tumor microenvironment to antagonize the growth of OSCCs, which provides a theoretical basis for developing new strategies to treat OSCCs in the future.

Exosomes derived from stem cells of human deciduous exfoliated teeth inhibit angiogenesis in vivo and in vitro via the transfer of miR-100-5p and miR-1246

Background

Anti-angiogenic therapy has been shown to be a promising strategy for anti-tumor treatment. Increasing evidence indicates that tumor angiogenesis is affected by exosomes that are secreted by mesenchymal stem cells (MSCs), but whether exosomes derived from MSCs suppress or promote angiogenesis remain paradoxical. The purpose of this study focused on understanding the potential role of exosomes derived from stem cells of human deciduous exfoliated teeth (SHED-Exos) in regulating angiogenesis and the underlying molecular mechanism.

Methods

Exosomes were isolated from supernatants of SHED cells using an exosome purification kit and were characterized by transmission electron microscopy, nanoparticle tracking analysis and western blot analysis. Cell Counting Kit-8, flow cytometric assays, western blots, wound healing and transwell migration assays were performed to characterize the roles of SHED-Exos on cell proliferation, apoptosis and migration of human umbilical vein endothelial cells (HUVECs). The anti-angiogenic activity of SHED-Exos was assessed via a tube formation assay of endothelial cells and angiogenesis-related factors were analyzed by western blotting. In vivo, we used the chick chorioallantoic membrane (CAM) assay and an oral squamous cell carcinoma (OSCC) xenograft transplantation model with nude mice that received multi-point injections at three-day intervals to evaluate the effects on angiogenesis. Furthermore, the sequencing of microRNAs (miRNAs) in SHED-Exos was performed to investigate the underlying anti-angiogenic mechanism.

Results

The results showed that SHED-Exos inhibit cell proliferation and migration and induce apoptosis in HUVECs. SHED-Exos suppress the tube-like structure formation of HUVECs in vitro. SHED-Exos downregulate several angiogenesis-related factors, including VEGFA, MMP-9 and ANGPT1. In vivo, the chick CAM assay verified that treatment with SHED-Exos inhibits micro-vascular formation, and importantly, significantly reduces the micro-vascular formation of tumors generated from xenografted OSCC cells, which was associated with the inhibition of tumor growth in vivo. Mechanistically, our data suggested that SHED-Exos are enriched with miR-100-5p and miR-1246 and are transferred to endothelial cells, which results in decreased tube formation via the down-regulation of VEGFA expression.

Conclusions

These results demonstrate that SHED-Exos inhibit angiogenesis in vitro and in vivo, which suggests that SHED-Exos could potentially serve as a novel and effective therapeutic approach for anti-angiogenic treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02764-9.

Recent Advances in Chinese Herbal Medicine for Cerebral Ischemic Reperfusion Injury

Cerebral ischemic reperfusion injury (CI/RI) is a critical factor that leads to a poor prognosis in patients with ischemic stroke. It is an extremely complicated pathological process that is clinically characterized by high rates of disability and mortality. Current available treatments for CI/RI, including mechanical and drug therapies, are often accompanied by significant side effects. Therefore, it is necessary to discovery new strategies for treating CI/RI. Many studies confirm that Chinese herbal medicine (CHM) was used as a potential drug for treatment of CI/RI with the advantages of abundant resources, good efficacy, and few side effects. In this paper, we investigate the latest drug discoveries and advancements on CI/RI, make an overview of relevant CHM, and systematically summarize the pathophysiology of CI/RI. In addition, the protective effect and mechanism of related CHM, which includes extraction of single CHM and CHM formulation and preparation, are discussed. Moreover, an outline of the limitations of CHM and the challenges we faced are also presented. This review will be helpful for researchers further propelling the advancement of drugs and supplying more knowledge to support the application of previous discoveries in clinical drug applications against CI/RI.

Application of Reverse Docking in the Research of Small Molecule Drugs and Traditional Chinese Medicine

With the development of structural biology and data mining, computer-aided drug design (CADD) has been playing an important role in all aspects of new drug development. Reverse docking, a method of virtual screening based on molecular docking in CADD, is widely used in drug repositioning, drug rescue, and traditional Chinese medicine (TCM) research, for it can search for macromolecular targets that can bind to a given ligand molecule. This review revealed the principle of reverse docking, summarized common target protein databases and docking procedures, and enumerated the applications of reverse docking in drug repositioning, adverse drug reactions, traditional Chinese medicine, and COVID-19 treatment. Hope our work can give some inspiration to researchers engaged in drug development.

Multiple regulation and targeting effects of borneol in the neurovascular unit in neurodegenerative diseases

Efficient delivery of brain-targeted drugs is highly important for the success of therapies in neurodegenerative diseases. Borneol has several biological activities, such as anti-inflammatory and cell penetration enhancing effect, and can regulate processes in the neurovascular unit (NVU), such as protein toxic stress, autophagosome/lysosomal system, oxidative stress, programmed cell death and neuroinflammation. However, the influence of borneol on NVU in neurodegenerative diseases has not been fully explained. This study searched the keywords 'borneol', 'neurovascular unit', 'endothelial cell', 'astrocyte', 'neuron', 'blood-brain barrier', 'neurodegenerative diseases' and 'brain disease', in PubMed, BioMed Central, China National Knowledge Infrastructure (CNKI), and Bing search engines to explore the influence of borneol on NVU. In addition to the principle and mechanism of penetration of borneol in the brain, this study also showed its multiple regulation effects on NVU. Borneol was able to penetrate the blood-brain barrier (BBB), affecting the signal transmission between BBB and the microenvironment of the brain, down-regulating the expression of inflammatory and oxidative stress proteins in NVU, especially in microglia and astrocytes. In summary, borneol is a potential drug delivery agent for drugs against neurodegenerative diseases.