3,3',4,5'-Tetramethoxy-trans-stilbene and 3,4',5-trimethoxy-trans-stilbene prevent oxygen-glucose deprivation-induced injury in brain endothelial cell.

Blood-brain barrier (BBB) disruption is a major pathophysiological event of ischemic stroke. Brain microvascular endothelial cells are critical to maintain homeostasis between central nervous system and periphery. Resveratrol protects against ischemic stroke. 3,3',4,5'-tetramethoxy-trans-stilbene (3,3',4,5'-TMS) and 3,4',5-trimethoxy-trans-stilbene (3,4',5-TMS) are resveratrol derivatives with addition of methoxy groups, showing better pharmacokinetic performance. We aimed to explore their protective effects and underlying mechanisms. Oxygen-glucose deprivation (OGD) model was applied in bEnd.3 cell line, mouse brain microvascular endothelium to mimic ischemia. The cells were pre-treated with 3,3',4,5'-TMS or 3,4',5-TMS (1 and 5 µM, 24 h) and then subjected to 2-h OGD injury. Cell viability, levels of proinflammatory cytokines and reactive oxygen species (ROS), and protein expressions were measured by molecular assays and fluorescence staining. OGD injury triggered cell death, inflammatory responses, ROS production and nuclear factor-kappa B (NF-κB) signalling pathway. These impairments were remarkably attenuated by the two stilbenes, 3,3',4,5'-TMS and 3,4',5-TMS. They also alleviated endothelial barrier injuries through upregulating the expression of tight junction proteins. Moreover, 3,3',4,5'-TMS and 3,4',5-TMS activated 5' adenosine monophosphate-activated protein kinase (AMPK) and endothelial nitric oxide synthase (eNOS). Overall, 3,3',4,5'-TMS and 3,4',5-TMS exert protective effects against OGD damage through suppressing cell death, inflammatory responses, oxidative stress, as well as BBB disruption on bEnd.3 cells.

Roles and Mechanisms of Dopamine Receptor Signaling in Catecholamine Excess Induced Endothelial Dysfunctions.

Endothelial dysfunction may contribute to pathogenesis of Takotsubo cardiomyopathy, but mechanism underlying endothelial dysfunction in the setting of catecholamine excess has not been clarified. The study reports that D1/D5 dopamine receptor signaling and small conductance calcium-activated potassium channels contribute to high concentration catecholamine induced endothelial cell dysfunction. For mimicking catecholamine excess, 100 µM epinephrine (Epi) was used to treat human cardiac microvascular endothelial cells. Patch clamp, FACS, ELISA, PCR, western blot and immunostaining analyses were performed in the study. Epi enhanced small conductance calcium-activated potassium channel current (ISK1-3) without influencing the channel expression and the effect was attenuated by D1/D5 receptor blocker. D1/D5 agonists mimicked the Epi effect, suggesting involvement of D1/D5 receptors in Epi effects. The enhancement of ISK1-3 caused by D1/D5 activation involved roles of PKA, ROS and NADPH oxidases. Activation of D1/D5 and SK1-3 channels caused a hyperpolarization, reduced NO production and increased ROS production. The NO reduction was membrane potential independent, while ROS production was increased by the hyperpolarization. ROS (H2O2) suppressed NO production. The study demonstrates that high concentration catecholamine can activate D1/D5 and SK1-3 channels through NADPH-ROS and PKA signaling and reduce NO production, which may facilitate vasoconstriction in the setting of catecholamine excess.

Protection of cultured vascular endothelial cells against cadmium cytotoxicity by simultaneous treatment or pretreatment with manganese.

Cadmium is a heavy metal that pollutes the environment and foods and is a risk factor for vascular disorders. We have previously demonstrated that pretreatment of vascular endothelial cells with zinc and copper protects the cells against cadmium cytotoxicity. In contrast, cadmium cytotoxicity was potentiated in cells following exposure to lead, thereby indicating that in vascular endothelial cells, cadmium cytotoxicity can be differentially modified by the co-occurrence of other heavy metals. In this study, we revealed that simultaneous treatment or pretreatment with manganese protects vascular endothelial cells against cadmium cytotoxicity. Intracellular accumulation of cadmium was observed to be reduced by simultaneous treatment with manganese, although not by pretreatment. The mRNA expression of metal transporters that regulate the uptake of both cadmium and manganese (ZIP8, ZIP14, and DMT1) remained unaffected by either simultaneous treatment or pretreatment with manganese, and simultaneous treatment with manganese suppressed the cadmium-induced expression of metallothionein but pretreatment with manganese did not exhibit such suppressive effect. Thus, the protection of vascular endothelial cells against cadmium cytotoxicity conferred by simultaneous treatment with manganese is assumed to be partially attributed to a reduction in the intracellular accumulation of cadmium, whereas the effects of pretreatment with manganese are independent of both the reduced intracellular accumulation of cadmium and the induction of metallothionein. These observations accordingly indicate that the protective effects of manganese are mediated via alternative (as yet unidentified) mechanisms.

Targeting endothelial glycolytic reprogramming by tsRNA-1599 for ocular anti-angiogenesis therapy.

Rationale: Current treatments for ocular angiogenesis primarily focus on blocking the activity of vascular endothelial growth factor (VEGF), but unfavorable side effects and unsatisfactory efficacy remain issues. The identification of novel targets for anti-angiogenic treatment is still needed. Methods: We investigated the role of tsRNA-1599 in ocular angiogenesis using endothelial cells, a streptozotocin (STZ)-induced diabetic model, a laser-induced choroidal neovascularization model, and an oxygen-induced retinopathy model. CCK-8 assays, EdU assays, transwell assays, and matrigel assays were performed to assess the role of tsRNA-1599 in endothelial cells. Retinal digestion assays, Isolectin B4 (IB4) staining, and choroidal sprouting assays were conducted to evaluate the role of tsRNA-1599 in ocular angiogenesis. Transcriptomic analysis, metabolic analysis, RNA pull-down assays, and mass spectrometry were utilized to elucidate the mechanism underlying angiogenic effects mediated by tsRNA-1599. Results: tsRNA-1599 expression was up-regulated in experimental ocular angiogenesis models and endothelial cells in response to angiogenic stress. Silencing of tsRNA-1599 suppressed angiogenic effects in endothelial cells in vitro and inhibited pathological ocular angiogenesis in vivo. Mechanistically, tsRNA-1599 exhibited little effect on VEGF signaling but could cause reduced glycolysis and NAD+/NADH production in endothelial cells by regulating the expression of HK2 gene through interacting with YBX1, thus affecting endothelial effects. Conclusions: Targeting glycolytic reprogramming of endothelial cells by a tRNA-derived small RNA represents an exploitable therapeutic approach for ocular neovascular diseases.

ß-asarone induces viability and angiogenesis and suppresses apoptosis of human vascular endothelial cells after ischemic stroke by upregulating vascular endothelial growth factor A.

Ischemic stroke (IS) is a disease with a high mortality and disability rate worldwide, and its incidence is increasing per year. Angiogenesis after IS improves blood supply to ischemic areas, accelerating neurological recovery. ß-asarone has been reported to exhibit a significant protective effect against hypoxia injury. The ability of ß-asarone to improve IS injury by inducing angiogenesis has not been distinctly clarified. The experimental rats were induced with middle cerebral artery occlusion (MCAO), and oxygen-glucose deprivation (OGD) model cells were constructed using human microvascular endothelial cell line (HMEC-1) cells. Cerebral infarction and pathological damage were first determined via triphenyl tetrazolium chloride (TTC) and hematoxylin and eosin (H&E) staining. Then, cell viability, apoptosis, and angiogenesis were assessed by utilizing cell counting kit-8 (CCK-8), flow cytometry, spheroid-based angiogenesis, and tube formation assays in OGD HMEC-1 cells. Besides, angiogenesis and other related proteins were identified with western blot. The study confirms that ß-asarone, like nimodipine, can ameliorate cerebral infarction and pathological damage. ß-asarone can also upregulate vascular endothelial growth factor A (VEGFA) and endothelial nitric oxide synthase (eNOS) and induce phosphorylation of p38. Besides, the study proves that ß-asarone can protect against IS injury by increasing the expression of VEGFA. In vitro experiments affirmed that ß-asarone can induce viability and suppress apoptosis in OGD-mediated HMEC-1 cells and promote angiogenesis of OGD HMEC-1 cells by upregulating VEGFA. This establishes the potential for ß-asarone to be a latent drug for IS therapy.

[Protective effect and mechanism of resveratrol on vascular endothelial cells].

Resveratrol is a polyphenolic plant extract with many biological activities such as anti-inflammation and anti-oxidative stress. Vascular endothelial cell (VEC) is the main sites for maintaining normal vascular permeability and participating in vasomotor regulation and substance exchange. VEC injury plays a key role in various diseases or pathological processes such as cardiovascular disease, chronic inflammation and sepsis. Studies have shown that resveratrol protects VEC and reduces endothelial damage by regulating nitric oxide (NO) and its related enzymes, reducing oxidative stress and inhibiting apoptosis, thereby exerting beneficial effects.

Gut-derived wild blueberry phenolic acid metabolites modulate extrinsic cutaneous damage.

As the first line of defense, the skin is equipped with various physiological mechanisms positioned to prevent incoming oxidative damage from numerous environmental insults. With persistent exposure to the environment, understanding ways to augment the skin defenses is paramount in protecting from premature aging. In this study, we investigated the ability of five dietary phenolic metabolites, typically found in the bloodstream after wild blueberry consumption, to successfully defend the skin from UV light exposure in a novel ex vivo co-culture model of human skin explants and primary endothelial cells. Skin explants, placed in transwell inserts, were exposed to UV, and subsequently co-cultured with endothelial cells. When the endothelial cells had been pretreated with the bioactive metabolites at physiological concentrations (hippuric acid 3000 nM, isoferulic acid 1000 nM, salicylic acid 130 nM, benzoic acid 900 nM, α-hydroxyhippuric acid 400 nM) cutaneous damage was prevented on the co-cultured with UV-challenged skin explants. Co-culture with non-pretreated endothelial cells did not protect skin explants. Specifically, the pretreatment was able to reduce skin lipid peroxidation (measured as 4-hydroxynonenal protein adducts), and pro-inflammatory enzymes such as cyclooxygenase 2 (COX-2) and NADPH oxidase 4 (NOX-4). Furthermore, pretreatment with the metabolites prevented UV-induced release of inflammatory cytokines such as IL-1ß and IL-8 as well as nitric oxides (NO) levels. In addition, the metabolites showed an impressive ability to prevent the loss of cutaneous structural proteins including involucrin and collagen type 1. Of note, endothelial cells cultured with UV exposed skin explants exhibited increased oxidative stress demonstrated by heme oxygenase-1 (HO-1) up-regulation which was significantly prevented in the metabolite treated models. These findings highlight the ability of dietary polyphenolic metabolites to improve cutaneous defenses against extrinsic stressors.

IGF-1 inhibits inflammation and accelerates angiogenesis via Ras/PI3K/IKK/NF-κB signaling pathways to promote wound healing.

Exogenous insulin-like growth factor-1 (IGF-1) has been reported to promote wound healing through regulation of vascular endothelial cells (VECs). Despite the existing studies of IGF-1 on VEC and its role in angiogenesis, the mechanisms regarding anti-inflammatory and angiogenetic effects of IGF-1 remain unclear. In this study, we investigated the wound-healing process and the related signaling pathway of IGF-1 using an inflammation model induced by IFN-γ. The results demonstrated that IGF-1 can increase cell proliferation, suppress inflammation in VECs, and promote angiogenesis. In vivo studies further confirmed that IGF-1 can reduce inflammation, enhance vascular regeneration, and improve re-epithelialization and collagen deposition in acute wounds. Importantly, the Ras/PI3K/IKK/NF-κB signaling pathways was identified as the mechanisms through which IGF-1 exerts its anti-inflammatory and pro-angiogenic effects. These findings contribute to the understanding of IGF-1's role in wound healing and may have implications for the development of new wound treatment approaches.

Eucalyptol Ameliorates Retinal Microvascular Defects through Modulating ER Stress and Angiopoietin-Tie Signaling in Diabetic Eyes.

Loss of the inner blood-retinal barrier (BRB) integrity is a main feature of ocular diseases such as diabetic macular edema. However, there is a lack of clarity on how inner BRB function is modulated within the diabetic retina. The current study examined whether eucalyptol inhibited inner BRB destruction and aberrant retinal angiogenesis in 33 mM glucose-exposed human retinal microvascular endothelial (RVE) cells and db/db mice. This study further examined the molecular mechanisms underlying endothelial dysfunction including retinal endoplasmic reticulum (ER) stress and angiopoietin (Ang)/Tie axis in conjunction with vascular endothelial growth factor (VEGF). Eucalyptol is a naturally occurring monoterpenoid and an achiral aromatic component of many plants including eucalyptus leaves. Nontoxic eucalyptol reduced the production of amyloid-ß (Aß) protein in glucose-loaded RVE cells and in diabetic mice. This natural compound blocked apoptosis of Aß-exposed RVE cells in diabetic mouse eyes by targeting ER stress via the inhibition of PERK-eIF2α-ATF4-CHOP signaling. Eucalyptol promoted activation of the Ang-1/Tie-2 pathway and dual inhibition of Ang-2/VEGF in Aß-exposed RVE cells and in diabetic eyes. Supply of eucalyptol reversed the induction of junction proteins in glucose/Aß-exposed RVE cells within the retina and reduced permeability. In addition, oral administration of eucalyptol reduced vascular leaks in diabetic retinal vessels. Taken together, these findings clearly show that eucalyptol inhibits glucose-induced Aß-mediated ER stress and manipulates Ang signaling in diabetic retinal vessels, which ultimately blocks abnormal angiogenesis and loss of inner BRB integrity. Therefore, eucalyptol provides new treatment strategies for diabetes-associated RVE defects through modulating diverse therapeutic targets including ER stress, Ang-1/Tie-2 signaling, and Ang-2/VEGF.

Buyang Huanwu Decoction suppresses ischemic stroke by suppressing glycolysis and cell apoptosis in rat brain microvascular endothelial cells.

BACKGROUND: Buyang Huanwu Decoction (BHD) is widely used in Chinese clinical practice for the treatment and prevention of ischemic cerebral vascular diseases. This study was designed to investigate the effects of BHD on ischemic stroke (IS) and its underlying mechanism. METHODS: The middle cerebral artery occlusion (MCAO) rat model and oxygen-glucose deprivation and reoxygenation (OGD/R) rat brain microvascular endothelial cell (RBMVEC) models were established. Brain infarction size and neurological score were calculated following MCAO surgery. Evans blue was used to measure blood brain barrier (BBB) permeability. Cell counting kit-8 (CCK-8) and TUNEL assays were performed to evaluate the cell viability and apoptosis of RBMVECs. Dual-luciferase reporter assay was used to analyze the transcriptional activities of apoptosis-related genes. RESULTS: Results showed that higher infarction volume, neurological scores, and BBB permeability in the MCAO group rats were reduced after BHD treatment. Drug serum (DS) treatment had no impact on the normal RBMVECs' cell viability and cell apoptosis. Besides, DS treatment decreased the lactate production, glucose uptake, and extracellular acidification rate in normal and OGD/R-induced RBMVECs. DS treatment downregulated the protein levels of pan-lysine lactylation (kla), histone H3 lysine 18 lactylation (H3K18la), and the transcriptional of apoptotic protease activating factor-1 (Apaf-1) in OGD/R-treated RBMVECs. In addition, Apaf-1 overexpression decreased cell viability and increased apoptosis and glycolysis activity of OGD/R-treated RBMVECs. CONCLUSION: In summary, BHD inhibited glycolysis and apoptosis via suppressing the pan-kla and H3K18la protein levels and the Apaf-1 transcriptional activity, thus restraining the progression of IS.

Sodium Tanshinone IIA Sulfonate alleviates vascular senescence in diabetic mice by modulating the A20-NFκB-NLRP3 inflammasome-catalase pathway.

Diabetes accelerates vascular senescence, which is the basis for atherosclerosis and stiffness. The activation of NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome and oxidative stress are closely associated with the deteriorative senescence in endothelial cells (ECs) and vascular smooth muscle cells (VSMCs). For decades, Sodium Tanshinone IIA Sulfonate (STS) has been utilized as a cardiovascular medicine with acknowledged anti-inflammatory and anti-oxidative properties. Nevertheless, the impact of STS on vascular senescence remains unexplored in diabetes. Diabetic mice, primary ECs and VSMCs were transfected with the NLRP3 overexpression/knockout plasmid, the tumor necrosis factor alpha-induced protein 3 (TNFAIP3/A20) overexpression/knockout plasmid, and treated with STS to detect senescence-associated markers. In diabetic mice, STS treatment maintained catalase (CAT) level and vascular relaxation, reduced hydrogen peroxide probe (ROSgreen) fluorescence, p21 immunofluorescence, Senescence ß-Galactosidase Staining (SA-ß-gal) staining area, and collagen deposition in aortas. Mechanistically, STS inhibited NLRP3 phosphorylation (serine 194), NLRP3 dimer formation, NLRP3 expression, and NLRP3-PYCARD (ASC) colocalization. It also suppressed the phosphorylation of IkappaB alpha (IκBα) and NFκB, preserved A20 and CAT levels, reduced ROSgreen density, and decreased the expression of p21 and SA-ß-gal staining in ECs and VSMCs under HG culture. Our findings indicate that STS mitigates vascular senescence by modulating the A20-NFκB-NLRP3 inflammasome-CAT pathway in hyperglycemia conditions, offering novel insights into NLRP3 inflammasome activation and ECs and VSMCs senescence under HG culture. This study highlights the potential mechanism of STS in alleviating senescence in diabetic blood vessels, and provides essential evidence for its future clinical application.

Pterostilbene Reverses Epigenetic Silencing of Nrf2 and Enhances Antioxidant Response in Endothelial Cells in Hyperglycemic Microenvironment.

The epigenetic regulation of nuclear factor erythroid 2-related factor 2 (Nrf2), a pivotal redox transcription factor, plays a crucial role in maintaining cellular homeostasis. Recent research has underscored the significance of epigenetic modifications of Nrf2 in the pathogenesis of diabetic foot ulcers (DFUs). This study investigates the epigenetic reversal of Nrf2 by pterostilbene (PTS) in human endothelial cells in a hyperglycemic microenvironment (HGM). The activation potential of PTS on Nrf2 was evaluated through ARE-Luciferase reporter assays and nuclear translocation studies. Following 72 h of exposure to an HGM, mRNA expression and protein levels of Nrf2 and its downstream targets NAD(P)H quinone oxidoreductase 1 (NQO1), heme-oxygenase 1(HO-1), superoxide dismutase (SOD), and catalase (CAT) exhibited a decrease, which was mitigated in PTS-pretreated endothelial cells. Epigenetic markers, including histone deacetylases (HDACs class I-IV) and DNA methyltransferases (DNMTs 1/3A and 3B), were found to be downregulated under diabetic conditions. Specifically, Nrf2-associated HDACs, including HDAC1, HDAC2, HDAC3, and HDAC4, were upregulated in HGM-induced endothelial cells. This upregulation was reversed in PTS-pretreated cells, except for HDAC2, which exhibited elevated expression in endothelial cells treated with PTS in a hyperglycemic microenvironment. Additionally, PTS was observed to reverse the activity of the methyltransferase enzyme DNMT. Furthermore, CpG islands in the Nrf2 promoter were hypermethylated in cells exposed to an HGM, a phenomenon potentially counteracted by PTS pretreatment, as shown by methyl-sensitive restriction enzyme PCR (MSRE-qPCR) analysis. Collectively, our findings highlight the ability of PTS to epigenetically regulate Nrf2 expression under hyperglycemic conditions, suggesting its therapeutic potential in managing diabetic complications.

Diosgenin alleviates arsenic trioxide induced cardiac fibrosis by inhibiting endothelial mesenchymal transition.

BACKGROUD: Arsenic trioxide (ATO), the first-line drug in treating acute premyelogenous leukemia, has the profound side effect of inducing endothelial mesenchymal transition (EndMT) and causing cardiac fibrosis. Diosgenin (DIO), a pharmaceutical compound found in Paris polyphylla, exhibits promising potential in safeguarding cardiovascular health by mitigating EndMT. PURPOSE: This study aims to explore the role and mechanism of DIO in ATO-induced myocardial fibrosis to provide a novel therapeutic agent for ATO-induced cardiac fibrosis. METHODS: Wistar rats were given DIO by gavage and ATO by tail vein. Cardiac function and fibrosis were evaluated by echocardiography and Masson's trichrome staining in rats. Human aortic endothelial cells (HAECs) were utilized to analyze ATO-induced EndMT in vitro. The cytoskeleton of HAECs was visualized using F-actin staining to observe cell morphology, while Dil-Ac-LDL staining was employed to assess cell functionality. EndMT-related factors (CD31 and α-SMA), glucocorticoid receptor (GR) and interleukin-6 (IL-6) were detected by immunofluorescence and Western blot in vivo and in vitro. Furthermore, GR was knocked down by si-GR, and IL-6 was blocked by IL-6 neutralizing antibody to verify their role in the effect of DIO on ATO-induced EndMT in HAECs. RESULTS: DIO exhibited significant efficacy in ATO-induced damage to both cardiac diastolic and systolic function, along with mitigating cardiac fibrosis. Additionally, DIO alleviated the loss of cytoskeletal anisotropy and enhanced the uptake of Dil-Ac-LDL in HAECs. Furthermore, it reversed the ATO-induced downregulation of endothelial-specific markers CD31 and GR, while suppressing the upregulation of mesenchymal markers α-SMA and IL-6, both in vivo and in vitro. Notably, the protective effect of DIO was compromised upon knockdown of GR, which also led to a reversal of DIO-induced IL-6 downregulation. Furthermore, the neutralization of IL-6 with specific antibodies abolished the ATO-induced changes related to EndMT. CONCLUSION: In this study, we clarified the protective effect of DIO on ATO-induced myocardial fibrosis against EndMT via the GR/IL-6 axis for the first time and provided a potential therapeutic agent for preventing heart damage caused by ATO.

Phloridzin Docosahexaenoate, an Omega-3 Fatty Acid Ester of a Flavonoid Precursor, Inhibits Angiogenesis by Suppressing Endothelial Cell Proliferation, Migration, and Differentiation.

Angiogenesis is a normal physiological process that also contributes to diabetic retinopathy-related complications and facilitates tumor metastasis by promoting the hematogenic dissemination of malignant cells from solid tumors. Here, we investigated the in vitro, ex vivo, and in vivo anti-angiogenic activity of phloridzin docosahexaenoate (PZ-DHA), a novel ω-3 fatty acid ester of a flavonoid precursor. Human umbilical vein endothelial cells (HUVEC) and human dermal microvascular endothelial cells (HMVEC) treated with a sub-cytotoxic concentration of PZ-DHA to assess in vitro anti-angiogenic activity showed impaired tubule formation on a Matrigel matrix. Ex vivo angiogenesis was measured using rat thoracic aortas, which exhibited reduced vessel sprouting and tubule formation in the presence of PZ-DHA. Female BALB/c mice bearing VEGF165- and basic fibroblast growth factor-containing Matrigel plugs showed a significant reduction in blood vessel development following PZ-DHA treatment. PZ-DHA inhibited HUVEC and HMVEC proliferation, as well as the migration of HUVECs in gap closure and trans-well cell migration assays. PZ-DHA inhibited upstream and downstream components of the Akt pathway and vascular endothelial growth factor (VEGF165)-induced overexpression of small molecular Rho GTPases in HUVECs, suggesting a decrease in actin cytoskeletal-mediated stress fiber formation and migration. Taken together, these findings reveal the potential of combined food biomolecules in PZ-DHA to inhibit angiogenesis.

Effects of tanshinone IIA on endothelial cell dysfunction in uremic condition.

An arteriovenous fistula (AVF) is the preferred vascular access for hemodialysis in uremic patients, yet its dysfunction poses a significant clinical challenge. Venous stenosis, primarily caused by venous neointimal hyperplasia, is a key factor in the failure of vascular access. During vascular access dysfunction, endothelial cells (ECs) transform mechanical stimuli into intracellular signals and interact with vascular smooth muscle cells. Tanshinone IIA, an important compound derived from Salvia miltiorrhiza, has been widely used to treat cardiovascular diseases. However, its role in modulating ECs under uremic conditions remains incompletely understood. In this research, ECs were exposed to sodium tanshinone IIA sulfonate (STS) and subjected to shear stress and uremic conditions. The results indicate that STS can reduce the suppressive effects on the expression of NF-κB p65, JNK and Collagen I in uremia-induced ECs. Moreover, the downregulation of NF-κB p65, JNK and Collagen I can be enhanced through the inhibition of ERK1/2 and the upregulation of Caveolin-1. These findings suggest that tanshinone IIA may improve EC function under uremic conditions by targeting the Caveolin-1/ERK1/2 pathway, presenting tanshinone IIA as a potential therapeutic agent against AVF immaturity caused by EC dysfunction.

Vascular Endothelial Growth Factor C (VEGF-C) Sensitizes Lymphatic Endothelial Cells to Oxidative-Stress-Induced Apoptosis through DNA Damage and Mitochondrial Dysfunction: Implications for Lymphedema.

Secondary lymphedema is caused by damage to the lymphatic system from surgery, cancer treatment, infection, trauma, or obesity. This damage induces stresses such as oxidative stress and hypoxia in lymphatic tissue, impairing the lymphatic system. In response to damage, vascular endothelial growth factor C (VEGF-C) levels increase to induce lymphangiogenesis. Unfortunately, VEGF-C often fails to repair the lymphatic damage in lymphedema. The underlying mechanism contributing to lymphedema is not well understood. In this study, we found that surgery-induced tail lymphedema in a mouse model increased oxidative damage and cell death over 16 days. This corresponded with increased VEGF-C levels in mouse tail lymphedema tissue associated with macrophage infiltration. Similarly, in the plasma of patients with secondary lymphedema, we found a positive correlation between VEGF-C levels and redox imbalance. To determine the effect of oxidative stress in the presence or absence of VEGF-C, we found that hydrogen peroxide (H2O2) induced cell death in human dermal lymphatic endothelial cells (HDLECs), which was potentiated by VEGF-C. The cell death induced by VEGF-C and H2O2 in HDLECs was accompanied by increased reactive oxygen species (ROS) levels and a loss of mitochondrial membrane potential. Antioxidant pre-treatment rescued HDLECs from VEGF-C-induced cell death and decreased ROS under oxidative stress. As expected, VEGF-C increased the number of viable and proliferating HDLECs. However, upon H2O2 treatment, VEGF-C failed to increase either viable or proliferating cells. Since oxidative stress leads to DNA damage, we also determined whether VEGF-C treatment induces DNA damage in HDLECs undergoing oxidative stress. Indeed, DNA damage, detected in the form of gamma H2AX (γH2AX), was increased by VEGF-C under oxidative stress. The potentiation of oxidative stress damage induced by VEFG-C in HDLECs was associated with p53 activation. Finally, the inhibition of vascular endothelial growth factor receptor-3 (VEGFR-3) activation blocked VEGF-C-induced cell death following H2O2 treatment. These results indicate that VEGF-C further sensitizes lymphatic endothelial cells to oxidative stress by increasing ROS and DNA damage, potentially compromising lymphangiogenesis.

Solid Lipid Nanoparticles Encapsulating a Benzoxanthene Derivative in a Model of the Human Blood-Brain Barrier: Modulation of Angiogenic Parameters and Inflammation in Vascular Endothelial Growth Factor-Stimulated Angiogenesis.

Lignans, a class of secondary metabolites found in plants, along with their derivatives, exhibit diverse pharmacological activities, including antioxidant, antimicrobial, anti-inflammatory, and antiangiogenic ones. Angiogenesis, the formation of new blood vessels from pre-existing ones, is a crucial process for cancer growth and development. Several studies have elucidated the synergistic relationship between angiogenesis and inflammation in various inflammatory diseases, highlighting a correlation between inflammation and vascular endothelial growth factor (VEGF)-induced angiogenesis. Thus, the identification of novel molecules capable of modulating VEGF effects presents promising prospects for developing therapies aimed at stabilizing, reversing, or even arresting disease progression. Lignans often suffer from low aqueous solubility and, for their use, encapsulation in a delivery system is needed. In this research, a bioinspired benzoxantene has been encapsulated in solid lipid nanoparticles that have been characterized for their pharmacotechnical properties and their thermotropic behavior. The effects of these encapsulated nanoparticles on angiogenic parameters and inflammation in VEGF-induced angiogenesis were evaluated using human brain microvascular endothelial cells (HBMECs) as a human blood-brain barrier model.

Ginsenoside Rg1 regulates astrocytes to promote angiogenesis in spinal cord injury via the JAK2/STAT3 signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Ginseng (Panax ginseng C. A. Mey) is a common traditional Chinese medicine used for anti-inflammation, anti-apoptosis, anti-oxidative stress, and neuroprotection. Ginsenosides Rg1, the main active components isolated from ginseng, may be a feasible therapy for spinal cord injury (SCI). AIMS OF THE STUDY: SCI causes endothelial cell death and blood vessel rupture, ultimately resulting in long-term neurological impairment. As a result, encouraging spinal angiogenesis may be a feasible therapy for SCI. This investigation aimed to validate the capacity of ginsenoside Rg1 in stimulating angiogenesis within the spinal cord. MATERIALS AND METHODS: Rats with SCI were injected intraperitoneally with ginsenoside Rg1. The effectiveness of ginsenoside Rg1 was assessed using the motor function score and the motor-evoked potential (MEP). Immunofluorescence techniques were applied to identify the spinal cord's angiogenesis. Angiogenic factors were examined through Western Blot (WB) and Immunohistochemistry. Oxygen-glucose deprivation (OGD) was employed to establish the hypoxia-ischemia model in vitro, and astrocytes (As) were given ginsenoside Rg1 and co-cultured with spinal cord microvascular endothelial cells (SCMECs). Immunofluorescence, wound healing test, and tube formation assay were used to identify the co-cultured SCMECs' activity. Finally, network pharmacology analysis and siRNA transfection were applied to verify the mechanism of ginsenoside Rg1 promoting angiogenesis. RESULTS: The rats with SCI treated with ginsenoside Rg1 indicated more significant functional recovery, more pronounced angiogenesis, and higher levels of angiogenic factor expression. In vitro, the co-culture system with ginsenoside Rg1 intervention improved SCMECs' capacity for proliferating, migrating, and forming tubes, possibly by promoting the expression of vascular endothelial growth factor (VEGF) in As via the janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway. CONCLUSION: Ginsenoside Rg1 can regulate As to promote angiogenesis, which may help to understand the mechanism of promoting SCI recovery.

Stigmast-4-en-3-one from Euonymus alatus (Thunb.) Siebold. improves diabetic retinopathy and angiogenesis mediated by glucocorticoids receptor.

ETHNOPHARMACOLOGICAL RELEVANCE: Euonymus alatus (Thunb.) Siebold. (EA), a traditional Chinese medicine, is widely used in the treatment of diabetes. Our group has previously found that EA could treat diabetic retinopathy (DR) and stigmast-4-en-3-one (Numbered E6) is the active substance responsible for inhibiting angiogenesis in vitro by EA. However, the effects and mechanisms of E6 in the treatment of DR is still unknown. AIM OF THE STUDY: The aim of this study was to investigate the effects and mechanisms of E6 in EA on DR. Additionally, a comparison was made between the effects of E6 and triamcinolone acetonide (TA), as well as the side effects of E6 and dexamethasone. MATERIALS AND METHODS: Ocular affinity assessment and pharmacokinetic parameter prediction were conducted to evaluate the potential of E6 to treat DR. Retinal endothelial cells were used to investigate the in vitro inhibitory effect of E6 on vascular proliferation. Additionally, chicken embryos, zebrafish, and mice were used to investigate the in vivo anti-vascular proliferation effect of E6. Finally, diabetic mice were used to investigate whether E6 improves diabetic retinopathy and to compare its efficacy with that of TA. We then used network pharmacology to study the targets of E6 and performed molecular docking; followed by immunofluorescence experiments, ELISA, Western blot, and tube formation experiments to further investigate its mechanism. Finally, we compared the side effects of E6 with those of dexamethasone. RESULTS: E6 was found to have an affinity for the eye and to inhibit vascular proliferation both in vivo and in vitro. Moreover, E6 was found to be more efficacious than TA in the treatment of DR. Molecular docking experiments predicted that the glucocorticoid receptor (GR) is a potential target of E6, and immunofluorescence analyses confirmed that E6 upregulated the expression of the GR in the retina of hyperglycemic mice. In addition, western blotting results and tube formation experiments showed that E6 also attenuated angiogenesis by inhibiting the Hippo and VEGF pathways. Finally, by comparing the effects of E6 and dexamethasone on glucose regulation and osteoporosis, E6 was found to have fewer side effects. CONCLUSIONS: E6 is a highly effective drug for the treatment of DR, superior to TA and with fewer side effects than dexamethasone. Its mechanism involves the activation of glucocorticoid receptor and inhibition of Hippo and VEGF pathways to alleviate angiogenesis and inflammation. This study is the first to investigate the role and mechanism of E6 in improving DR. The findings suggest that E6 has unique advantages in the treatment of DR.

Targeting monocytic Occludin impairs transendothelial migration and HIV neuroinvasion.

Transmigration of circulating monocytes from the bloodstream to tissues represents an early hallmark of inflammation. This process plays a pivotal role during viral neuroinvasion, encephalitis, and HIV-associated neurocognitive disorders. How monocytes locally unzip endothelial tight junction-associated proteins (TJAPs), without perturbing impermeability, to reach the central nervous system remains poorly understood. Here, we show that human circulating monocytes express the TJAP Occludin (OCLN) to promote transmigration through endothelial cells. We found that human monocytic OCLN (hmOCLN) clusters at monocyte-endothelium interface, while modulation of hmOCLN expression significantly impacts monocyte transmigration. Furthermore, we designed OCLN-derived peptides targeting its extracellular loops (EL) and show that transmigration of treated monocytes is inhibited in vitro and in zebrafish embryos, while preserving vascular integrity. Monocyte transmigration toward the brain is an important process for HIV neuroinvasion and we found that the OCLN-derived peptides significantly inhibit HIV dissemination to cerebral organoids. In conclusion, our study identifies an important role for monocytic OCLN during transmigration and provides a proof-of-concept for the development of mitigation strategies to prevent monocyte infiltration and viral neuroinvasion.