Pharmacological inhibition of epidermal growth factor receptor attenuates intracranial aneurysm formation by modulating the phenotype of vascular smooth muscle cells

Titanium surfaces loaded with puerarin and exosomes derived from adipose stem cells promote the proliferation and differentiation of pre-osteoblasts

The study is to evaluate the effects of collagen/hyaluronic acid coating with or without puerarin and exosomes (Exos) derived from adipose stem cells (ADSCs-Exos) on pre-osteoblast proliferation and differentiation on the surface of titanium materials. Titanium materials with different coatings were prepared by layer-by-layer technique, evaluating the surface characterization. Cell functions were assessed by cell biology experiments. Related genes and proteins were assessed by RT-qPCR and Western blot. Puerarin or ADSCs-Exos coating had better effects on promoting the adhesion, proliferation and differentiation of pre-osteoblasts, and the strongest effect was found after their co-coatings, manifesting as the up-regulations of alkaline phosphatase (ALP) activity, collagen type I alpha 1 (Col1a1), runt-related transcription factor 2 (Runx2), osterix and activating transcription factor-2 (ATF-2). Levels of phosphorylated-P38 (p-P38) and p-ATF-2 were up-regulated in pre-osteoblasts grown on puerarin and ADSCs-Exos-loaded titanium surfaces. Titanium surfaces loaded with puerarin and ADSCs-Exos promotes the proliferation and differentiation of pre-osteoblasts.

Effects of KLF11 on Vascular Smooth Muscle Cells and its Underlying Mechanisms in Intracranial Aneurysm

Vascular smooth muscle cells (VSMCs) affect the phenotypic changes in intracranial aneurysm (IA). They exhibit enhanced dissociation and migration and play a key role in IA pathogenesis. KLF transcription factor 11 (KLF11), a member of the KLF family, significantly affects the cancer cell proliferation, differentiation, and apoptosis. However, its expression, biological functions, and latent action mechanisms in IA remain unclear. This study aimed to analyze the effects of KLF11 on H2O2-induced human brain VSMCs (HBVSMCs) in IA. We determined the mRNA levels of KLF11 in 15 paired arterial wall tissues of patients with IA and healthy volunteers. HBVSMCs were stimulated with H2O2 for 6 h to establish an IA model in vitro. Cell viability, apoptosis, and inflammatory cytokine (interleukin [IL-1β, tumor necrosis factor-α, and IL-6) levels were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2-5-diphenyltetrazolium bromide, flow cytometry, and enzyme-linked immunosorbent assays, respectively. KLF11 expression was determined via quantitative reverse transcription-polymerase chain reaction, western blotting, and immunofluorescence analyses. Furthermore, p-p38, p38, cleaved-caspase 3, and caspase 3 levels were determined via western blotting. KLF11 levels were downregulated in the arterial wall tissues of patients with IA than in those of the control group. KLF11 upregulation by KLF11-plasmid promoted the cell viability, reduced apoptosis, decreased cleaved-caspase 3 expression, and inhibited the secretion of inflammatory factors in H2O2-induced HBVSMCs. KLF11-plasmid remarkably reduced p-p38 expression and p-p38/p-38 ratio; however, these effects were reversed by P79350 treatment. Overall, KLF11 upregulation improved the HBVSMC functions and exerted protective effects against IA, suggesting its potential for IA treatment.

Geniposide modulates GSK3β to inhibit Th17 differentiation and mitigate endothelial damage in intracranial aneurysm

Intracranial aneurysm (IA) is a common cerebrovascular disease. Immune system disorders and endothelial dysfunction are essential mechanisms of its pathogenesis. This study aims to explore the therapeutic effect and mechanism of Geniposide (Gen) on IA, which has a protective impact on endothelial cells and cardiovascular and cerebrovascular diseases. IA mouse models were administered intraperitoneal injections of geniposide for 2 weeks following elastase injection into the right basal ganglia of the brain for intervention. The efficacy of Gen in treating IA was evaluated through pathological testing and transcriptome sequencing analysis of Willis ring vascular tissue. The primary mechanism of action was linked to the expression of GSK3β in Th17 cells. The percentage of splenic Th17 cell differentiation in IA mice was significantly inhibited by Gen. GSK3β/STAT3, and other pathway protein expression levels were also significantly inhibited by Gen. Additionally, TNF-α and IL-23 cytokine contents were significantly downregulated after Gen treatment. These results indicated that Gen significantly inhibited the percentage of Th17 cell differentiation, an effect that was reversed upon overexpression of the GSK3B gene. Furthermore, Gen-treated, Th17 differentiation-inducing cell-conditioned medium significantly up-regulated the expression of tight junction proteins ZO-1, Occludin, and Claudin-5 in murine aortic endothelial cells. Administering the GSK3β inhibitor Tideglusib to IA mice alleviated the severity of IA disease pathology and up-regulated aortic tight junction protein expression. In conclusion, Gen inhibits Th17 cell differentiation through GSK3β, which reduces endothelial cell injury and up-regulates tight junction protein expression.

Phoenixin-14 maintains the contractile type of vascular smooth muscle cells in cerebral aneurysms rats

The rupture of intracranial aneurysm (IA) is the primary reason contributing to the occurrence of life-threatening subarachnoid hemorrhages. The oxidative stress-induced phenotypic transformation from the contractile phenotype to the synthetic phenotype of vascular smooth muscle cells (VSMCs) plays a pivotal role in IA formation and rupture. Our study aimed to figure out the role of phoenixin-14 in VSMC phenotypic switching during the pathogenesis of IA by using both cellular and animal models. Primary rat VSMCs were isolated from the Willis circle of male Sprague-Dawley rats. VSMCs were stimulated by hydrogen peroxide (H2O2) to establish a cell oxidative damage model. After pretreatment with phoenixin-14 and exposure to H2O2, VSMC viability, migration, and invasion were examined through cell counting kit-8 (CCK-8), wound healing, and Transwell assays. Intracellular reactive oxygen species (ROS) production in VSMCs was evaluated by using 2',7'-Dichlorofluorescin diacetate (DCFH-DA) fluorescence probes and flow cytometry. Rat IA models were established by ligation of the left common carotid arteries and posterior branches of both renal arteries. The histopathological changes of rat intracranial blood vessels were observed through hematoxylin and eosin staining. The levels of contractile phenotype markers (alpha-smooth muscle actin [α-SMA] and smooth muscle 22 alpha [SM22α]) in VSMCs and rat arterial rings were determined through real-time quantitative polymerase chain reaction (RT-qPCR) and western blot analysis. Our results showed that H2O2 stimulated the production of intracellular ROS and induced oxidative stress in VSMCs, while phoenixin-14 pretreatment attenuated intracellular ROS levels in H2O2-exposed VSMCs. H2O2 exposure promoted VSMC migration and invasion, which, however, was reversed by phoenixin-14 pretreatment. Besides, phoenixin-14 administration inhibited IA formation and rupture in rat models. The decrease in α-SMA and SM22α levels in H2O2-exposed VSMCs and IA rat models was antagonized by phoenixin-14. Collectively, phoenixin-14 ameliorates the progression of IA through preventing the loss of the contractile phenotype of VSMCs.

Pharmaceutical Modulation of Intracranial Aneurysm Development and Rupture

Management of intracranial aneurysms (IAs) is determined by patient age, risk of rupture, and comorbid conditions. While endovascular and microsurgical interventions offer solutions to mitigate the risk of rupture, pharmacological management strategies may complement these approaches or serve as alternatives in appropriate cases. The pathophysiology of IAs allows for the targeting of inflammation to prevent the development and rupture of IAs. The aim of this review is to provide an updated summary of different pharmaceutical management strategies for IAs. Acetylsalicylic acid and renin-angiotensin-aldosterone system (RAAS) inhibitor antihypertensives have some evidence supporting their protective effect. Studies of selective cyclooxygenase-2 (COX-2) inhibitors, statins, ADP inhibitors, and other metabolism-affecting drugs have demonstrated inconclusive findings regarding their association with aneurysm growth or rupture. In this manuscript, we highlight the evidence supporting each drug's effectiveness.

Interstitial Fluid Shear Stress Induces the Synthetic Phenotype Switching of VSMCs to Release Pro-calcified Extracellular Vesicles via EGFR-MAPK-KLF5 Pathway

Phenotypic switching (from contractile to synthetic) of vascular smooth muscle cells (VSMCs) is essential in the progression of atherosclerosis. The damaged endothelium in the atherosclerotic artery exposes VSMCs to increased interstitial fluid shear stress (IFSS). However, the precise mechanisms by which increased IFSS influences VSMCs phenotypic switching are unrevealed. Here, we employed advanced numerical simulations to calculate IFSS values accurately based on parameters acquired from patient samples. We then carefully investigated the phenotypic switching and extracellular vesicles (EVs) secretion of VSMCs under various IFSS conditions. By employing a comprehensive set of approaches, we found that VSMCs exhibited synthetic phenotype upon atherosclerotic IFSS. This synthetic phenotype is the upstream regulator for the enhanced secretion of pro-calcified EVs. Mechanistically, as a mechanotransducer, the epidermal growth factor receptor (EGFR) initiates the flow-based mechanical cues to MAPK signaling pathway, facilitating the nuclear accumulation of the transcription factor krüppel-like factor 5 (KLF5). Furthermore, pharmacological inhibiting either EGFR or MAPK signaling pathway blocks the nuclear accumulation of KLF5 and finally results in the maintenance of contractile VSMCs even under increased IFSS stimulation. Collectively, targeting this signaling pathway holds potential as a novel therapeutic strategy to inhibit VSMCs phenotypic switching and mitigate the progression of atherosclerosis.

Evaluation of the EMBOPIPE flow diverter device: in vivo and in vitro experiments

BACKGROUND

Although flow diverter device (FDD) has brought revolutionized advances in endovascular treatment of intracranial aneurysms, it also presents considerable drawbacks as well, as the innovation for novel device has never stopped. This preclinical research aims to evaluate the safety and efficacy of a newly developed FDD, the EMBOPIPE, through in vivo and in vitro experiments.

METHODS

Aneurysms were induced in 20 New Zealand white rabbits which were randomized to three follow-up groups according to the time elapsed after EMBOPIPE implantation (28, 90, and 180 days). Additional EMBOPIPEs were implanted in the abdominal aorta to cover the renal artery in nine rabbits. Angiography was performed immediately after device placement in all groups. Aneurysm occlusion, patency of renal arteries, and pathological outcomes were assessed. For the in vitro experiments, we measured the thrombogenic potential of EMBOPIPEs (n = 5) compared with bare stents (n = 5) using the Chandler loop model. Evaluation indicators were the platelet counts, macroscopic observations and scanning electron microscopy.

RESULTS

EMBOPIPEs were successfully deployed in 19 of 20 rabbit aneurysms (95.0%). The rates of complete or near-complete aneurysm occlusion were 73.3%, 83.3%, and 100% in the 28-, 90-, and 180-day groups, respectively. All renal arteries covered by EMBOPIPEs remained patent, and the mean difference in renal artery diameter before and after the device placement in the three groups was 0.07 mm, 0.10 mm, and 0.10 mm, respectively (p = 0.77). Renal pathology was normal in all cases. The pathological findings of the aneurysms were as follows: thickened and adequate neointimal coverage at the aneurysm neck, minimal inflammatory response, near-complete smooth muscle cell layer, and endothelialization along the device. In vitro experiments showed that the platelet counts were significantly higher in EMBOPIPE blood samples than in bare stent samples and that platelet adhesion to the device was lower in the EMBOPIPE stent struts compared with bare stent struts through macroscopic observations and scanning electron microscopy.

CONCLUSIONS

The EMBOPIPE can achieve high rates of aneurysm occlusion while maintaining excellent branch artery patency. It exhibited wonderful pathological results. This novel device with phosphorylcholine surface modification could reduce platelet thrombus attached to the stent struts.

WNTA5-mediated miR-374a-5p regulates vascular smooth muscle cell phenotype transformation and M1 macrophage polarization impacting intracranial aneurysm progression

miR-374a-5p expression and localization in intracranial aneurysm (IA) tissues were detected, and its correlation with vascular smooth muscle cells (VSMCs) and macrophage markers was analyzed. Using platelet-derived growth factor-BB (PDGF-BB) induced VSMC model, elastase-induced IA rat model. Subsequently, miR-374a-5p was knocked down or overexpressed. We investigated the effects of miR-374a-5p on phenotypic conversion, and in vivo experiments were also carried out to verify the findings. The targeted relationship between miR-374a-5p and WNTA5 was analyzed. The effect of WNT5A inhibition on VSMC phenotypic transformation and THP-1-derived macrophage polarization was explored. Clinical studies have shown that miR-374a-5p was upregulated in IA patients. miR-374a-5p was negatively correlated with SM22α, α-SMA, CD206, and positively correlated with CD86. In vitro experiments showed that knocking down miR-374a-5p reversed the promotion of SM22α and α-SMA expression by PDGF-BB, while overexpression of miR-374a-5p had the opposite effect. In addition, knocking down miR-374a-5p also reversed the decrease in Calponin, TIMP3, TIMP4, and IL-10 levels caused by PDGF-BB, and further reduced the levels of MMP1, MMP3, MMP9, IL-1β, IL-6, and TNF-α. These findings were further validated in vivo. In IA rats, there were notable increases in both systolic and diastolic blood pressure, along with an elevated M1/M2 ratio and the occurrence of vascular lesions. However, these symptoms were improved after knocking down miR-374a-5p. Furthermore, miR-374a-5p could target the WNT signals (WNT2B, WNT3, and WNT5A). miR-374a-5p regulated the VSMC phenotypic conversion and M1 macrophage polarization by targeting WNT5A, thereby impacting the progression of IA.

Receptor Tyrosine Kinase: Still an Interesting Target to Inhibit the Proliferation of Vascular Smooth Muscle Cells

Vascular smooth muscle cells (VSMCs) proliferation is a critical event that contributes to the pathogenesis of vascular remodeling such as hypertension, restenosis, and pulmonary hypertension. Increasing evidences have revealed that VSMCs proliferation is associated with the activation of receptor tyrosine kinases (RTKs) by their ligands, including the insulin-like growth factor receptor (IGFR), fibroblast growth factor receptor (FGFR), epidermal growth factor receptor (EGFR), vascular endothelial growth factor receptor (VEGFR), and platelet-derived growth factor receptor (PDGFR). Moreover, some receptor tyrosinase inhibitors (TKIs) have been found and can prevent VSMCs proliferation to attenuate vascular remodeling. Therefore, this review will describe recent research progress on the role of RTKs and their inhibitors in controlling VSMCs proliferation, which helps to better understand the function of VSMCs proliferation in cardiovascular events and is beneficial for the prevention and treatment of vascular disease.

Vascular smooth muscle cells in intracranial aneurysms

Intracranial aneurysm (IA) is a severe cerebrovascular disease characterized by abnormal bulging of cerebral vessels that may rupture and cause a stroke. The expansion of the aneurysm accompanies by the remodeling of vascular matrix. It is well-known that vascular remodeling is a process of synthesis and degradation of extracellular matrix (ECM), which is highly dependent on the phenotype of vascular smooth muscle cells (VSMCs). The phenotypic switching of VSMC is considered to be bidirectional, including the physiological contractile phenotype and alternative synthetic phenotype in response to injury. There is increasing evidence indicating that VSMCs have the ability to switch to various phenotypes, including pro-inflammatory, macrophagic, osteogenic, foamy and mesenchymal phenotypes. Although the mechanisms of VSMC phenotype switching are still being explored, it is becoming clear that phenotype switching of VSMCs plays an essential role in IA formation, progression, and rupture. This review summarized the various phenotypes and functions of VSMCs associated with IA pathology. The possible influencing factors and potential molecular mechanisms of the VSMC phenotype switching were further discussed. Understanding how phenotype switching of VSMC contributed to the pathogenesis of unruptured IAs can bring new preventative and therapeutic strategies for IA.

FDA-Approved Kinase Inhibitors in Preclinical and Clinical Trials for Neurological Disorders

Cancers and neurological disorders are two major types of diseases. We previously developed a new concept termed "Aberrant Cell Cycle Diseases" (ACCD), revealing that these two diseases share a common mechanism of aberrant cell cycle re-entry. The aberrant cell cycle re-entry is manifested as kinase/oncogene activation and tumor suppressor inactivation, which are hallmarks of both tumor growth in cancers and neuronal death in neurological disorders. Therefore, some cancer therapies (e.g., kinase inhibition, tumor suppressor elevation) can be leveraged for neurological treatments. The United States Food and Drug Administration (US FDA) has so far approved 74 kinase inhibitors, with numerous other kinase inhibitors in clinical trials, mostly for the treatment of cancers. In contrast, there are dire unmet needs of FDA-approved drugs for neurological treatments, such as Alzheimer's disease (AD), intracerebral hemorrhage (ICH), ischemic stroke (IS), traumatic brain injury (TBI), and others. In this review, we list these 74 FDA-approved kinase-targeted drugs and identify those that have been reported in preclinical and/or clinical trials for neurological disorders, with a purpose of discussing the feasibility and applicability of leveraging these cancer drugs (FDA-approved kinase inhibitors) for neurological treatments.

Phoenixin-14 alleviates inflammatory smooth muscle cell-induced endothelial cell dysfunction in vitro

BACKGROUND

Intracranial aneurysm (IA) is cerebrovascular disorder which refers to local vessel wall damage to intracranial arteries, forming abnormal bulge. Both endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) are closely associated with IA formation and rupture. Inflammatory SMCs (iSMCs) were reported to induce EC dysfunction and result in IA progression. Phoenixin-14 (PNX-14) is a recently discovered brain peptide with pleiotropic roles, which participates in reproduction, cardio protection, lipid deposition and blood glucose metabolism. PNX-14 was previously reported to protect brain endothelial cells against oxygen-glucose deprivation/reoxygenation (OGD/R)-induced cell injury. Therefore, our study was designed to investigate the influence of PNX-14 on iSMCs-induced endothelial dysfunction.

METHODS

Inflammation in SMCs was induced by cyclic mechanical stretch. Human umbilical vein endothelial cells (HUVECs) were exposed to SMC- or iSMC-conditioned medium and then treated with 100 nM PNX-14 for 24 h. The levels of proinflammatory cytokines (IL-1β, IL-6 and TNF-α) in cell supernatants were analyzed by ELISA. Cell viability, apoptosis, angiogenesis and migration were subjected to CCK-8 assay, flow cytometry analysis, tube formation assay and Transwell migration assay. The protein levels of proinflammatory cytokines and apoptosis markers (Bcl-2 and Bax) were evaluated by western blotting.

RESULTS

Cyclic mechanical stretch upregulated IL-1β, IL-6 and TNF-α levels in SMCs. Treatment with SMC- or iSMC-conditioned medium HUVECs inhibited cell viability, angiogenesis and migration and induced apoptosis in HUVECs. iSMC-conditioned medium has more significant effects on cell functions. However, the influence of SMC- or iSMC-conditioned medium treatment on HUVEC biological functions were reversed by PNX-14 treatment. PNX-14 exerts no significant influence on the biological functions of HUVECs treated with SMC medium.

CONCLUSION

PNX-14 alleviates iSMCs-induced endothelial cell dysfunction in vitro.

Hsa_circ_0031608: A Potential Modulator of VSMC Phenotype in the Rupture of Intracranial Aneurysms

Background and Purpose

Phenotypic modulation of vascular smooth muscle cells (VSMCs) plays an important role in the development of intracranial aneurysms (IAs). Growing evidence has demonstrated that circular RNAs (circRNAs) may serve as a potential modulator of VSMC phenotype in various vascular diseases. This study aimed to assess the potential function of circRNAs in the rupture of IAs and VSMC phenotypic modulation.

Methods

Using surgically dissected human ruptured (n = 8) and unruptured (n = 8) IA lesions, differentially expressed circRNAs were screened by transcriptomic sequencing and verified using qRT-PCR. Based on the screened circRNA, we predicted and screened the combined miRNA and downstream mRNAs to construct circRNA-miRNA-mRNA networks. Further in vitro experiments were performed to investigate the relationship between the validated circRNA and the phenotypic switching of VSMCs.

Results

We found 1,373 differentially expressed genes in ruptured versus unruptured aneurysms. The top five dysregulated circRNAs were selected for qRT-PCR validation. We found hsa_circ_0031608 was both highly expressed in ruptured IAs and pro-inflammatory transformation of VSMCs. Then, a regulatory circRNA-miRNA-mRNA with one circRNA node, six miRNA nodes, and 84 mRNA nodes was constructed. GO analysis and KEGG pathway enrichment analysis were performed on mRNAs in the network. Then, a PPI network was built based on these mRNAs and five hub genes were identified (FOXO3, DICER1, CCND2, IGF1R, and TNRC6B) by the cytoHubba plugin in Cytoscape software. In vitro, overexpression of hsa_circ_0031608 influenced the expression of VSMC phenotypic markers validated by qPCR and Western blotting. Furthermore, hsa_circ_0031608 promoted the migration and proliferation capacity of VSMCs.

Conclusion

hsa_circ_0031608 regulated the phenotypic modulation of VSMCs and played an important role in the rupture of IAs. The specific mechanism should be further studied and confirmed.