Plexin D1 negatively regulates macrophage-derived foam cell migration via the focal adhesion kinase/Paxillin pathway.

BACKGROUND: Macrophage-derived foam cell formation is a hallmark of atherosclerosis and is retained during plaque formation. Strategies to inhibit the accumulation of these cells hold promise as viable options for treating atherosclerosis. Plexin D1 (PLXND1), a member of the Plexin family, has elevated expression in atherosclerotic plaques and correlates with cell migration; however, its role in macrophages remains unclear. We hypothesize that the guidance receptor PLXND1 negatively regulating macrophage mobility to promote the progression of atherosclerosis. METHODS: We utilized a mouse model of atherosclerosis based on a high-fat diet and an ox-LDL- induced foam cell model to assess PLXND1 levels and their impact on cell migration. Through western blotting, Transwell assays, and immunofluorescence staining, we explored the potential mechanism by which PLXND1 mediates foam cell motility in atherosclerosis. RESULTS: Our study identifies a critical role for PLXND1 in atherosclerosis plaques and in a low-migration capacity foam cell model induced by ox-LDL. In the aortic sinus plaques of ApoE-/- mice, immunofluorescence staining revealed significant upregulation of PLXND1 and Sema3E, with colocalization in macrophages. In macrophages treated with ox-LDL, increased expression of PLXND1 led to reduced pseudopodia formation and decreased migratory capacity. PLXND1 is involved in regulating macrophage migration by modulating the phosphorylation levels of FAK/Paxillin and downstream CDC42/PAK. Additionally, FAK inhibitors counteract the ox-LDL-induced migration suppression by modulating the phosphorylation states of FAK, Paxillin and their downstream effectors CDC42 and PAK. CONCLUSION: Our findings indicate that PLXND1 plays a role in regulating macrophage migration by modulating the phosphorylation levels of FAK/Paxillin and downstream CDC42/PAK to promoting atherosclerosis.

Anti-hepatocellular carcinoma activity of Sorbaria sorbifolia by regulating VEGFR and c-Met/apoptotic pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Sorbaria sorbifolia (SS) is a traditional Chinese medicine (TCM) that has been employed anti-hepatocellular carcinoma (HCC) for over 2000 years; yet, its underlying mechanism is still not fully understood. AIM OF THE STUDY: In this study, we evaluated the anti-HCC effect on the freeze-dried powder of the water extract of SS (FDSS) by inhibiting tumor-induced neovascularization, and promoting apoptosis, and elucidated the underlying mechanisms. MATERIALS AND METHODS: HCC cell lines (HepG2 and Huh7 cells) and HepG2 xenograft tumors in zebrafish were employed as in vivo and in vitro models, respectively, to evaluate the anti- HCC-indued neovascularization and apoptosis. In HCC cell lines, CCK-8 assay, wound-healing assay, transwell assay, cell circle assay, apoptosis assay, transmission electron microscopy, and co-culture assay were performed in vitro; in HepG2 xenograft tumor-zebrafish, tumor growth inhibition assay, hematoxylin and eosin (HE) staining, xenograft tumor-zebrafish apoptosis assay, and HCC-indued neovascularization assay were performed to evaluate the effect of FDSS on biological behavior of tumor, HCC-indued neovascularization, and apoptosis. The expression of VEGFR and c-Met/apoptotic pathway-related proteins was detected by western blotting analysis. Assays for c-Met and VEGFR activation were conducted to assess the impact of FDSS in either agonistic or inhibitory roles on these receptor proteins. RESULTS: The findings from our study revealed that FDSS effectively suppresses the proliferation, migration, and invasion of HepG2 and Huh7 cells, as well as inhibiting tumor growth in the HepG2 xenograft zebrafish model by downregulating the expression of p-Met and p-AKT proteins. FDSS decreased the tumor growth associated with promoting apoptosis, including arresting HepG2 and Huh7 cells cycle at G0/G1phase, increasing apoptotic cell numbers and apoptotic bodies in cancer cells, and increasing the apoptotic fluorescence of xenograft tumor zebrafish by downregulating Bcl-2 proteins and upregulating Bax, caspase-9, and caspase-3 levels. We also found that FDSS can inhibit HCC-induced neovascularization and regulate VEGFR. Using an agonist or inhibitor of c-Met and VEGFR in HepG2 cells, we discovered that FDSS can downregulate c-Met and VEGFR protein expression. CONCLUSION: FDSS exerts an anti-HCC effect by inhibiting HCC-indued neovascularization and pro-apoptosis through the inhibition of the action of VEGFR and c-Met/apoptotic pathway.

Phosphorylation of USP27X by GSK3ß maintains the stability and oncogenic functions of CBX2.

Chromobox protein homolog 2 (CBX2) exerts a multifaceted impact on the progression of aggressive cancers. The proteasome-dependent pathway is crucial for modulating CBX2 regulation, while the specific regulatory roles and mechanisms of deubiquitinating enzymes targeting CBX2 remain poorly understood. Mass spectrometry analysis identified ubiquitin-specific peptidase 27X (USP27X) as a deubiquitinating enzyme that targets CBX2. Overexpression of USP27X significantly enhances CBX2 levels by promoting deubiquitination, while deficiency of USP27X leads to CBX2 degradation, thereby inhibiting tumorigenesis. Furthermore, it has been revealed that glycogen synthase kinase 3 beta (GSK3ß) can directly bind to and phosphorylate USP27X, thereby enhancing the interaction between USP27X and CBX2 and leading to further stabilization of the CBX2 protein. Clinically, the co-expression of high levels of USP27X and CBX2 in breast cancer tissues is indicative of a poor prognosis for patients with this disease. These findings collectively underscore the critical regulatory role played by USP27X in modulating CBX2, thereby establishing the GSK3ß-USP27X-CBX2 axis as a pivotal driver of malignant progression in breast cancer.

Mongolian Medicine echinops prevented postmenopausal osteoporosis and induced ER/AKT/ERK pathway in BMSCs.

Hormone replacement medicine such as traditional Chinese medicine has proven to be effective in decreasing the risk of osteoporosis. Mongolian medicine echinops prevents osteoporosis, but its mechanism remains unclear. In this study, we explored the mechanism underlying echinops prevents and treats postmenopausal osteoporosis. Osteoporosis model was established by ovariectomy in rats. Rats were treated to Echinops (16.26, 32.5, or 65 mg/kg/day) by oral gavage for 3 months. Bone mineral density (BMD) was detected by micro-CT detection of left proximal medial metaphyseal tibia. Hematoxylin and eosin (H&E) and toluidine blue O staining were also performed. Serum levels of E2, ALP and testosterone were examined. Bone marrow-derived bone marrow stem cells (BMSCs) were isolated and treated with echinops-containing serum. Estrogen receptors (ER) including ERα and ERß in bone specimens and BMSCs were detected by qRT-PCR. Cell viability and colon formation of BMSCs were detected. Expressions of ERα, ERß, AKT, p-AKT, ERK, and p-ERK in BMSCs were detected by western blot. Results showed that echinops significantly increased trabecular interconnectivity, thickness of trabeculae, and connection of trabecula. Echinops significantly increased BMD and E2, but significantly reduced ALP and testosterone in dose-dependent manners. Echinops induced ERα and ERß in both bone specimens and BMSCs. Echinops enhanced cell viability and ability of colony formation of BMSCs, and increased ERα, ERß, p-AKT, and p-ERK. Thus, Mongolian echinops reduced bone loss and delayed the occurrence and development of osteoporosis, and increased ERα, ERß, p-AKT, and P-ERK in BMSCs. These results provide experimental basis for clinical prevention and treatment of postmenopausal osteoporosis by echniops.