Retinopathy of prematurity (ROP) is a vision-threatening disorder that leads to pathological growth of the retinal vasculature due to hypoxia. Here, we investigated the potential effects of alamandine, a novel heptapeptide in the renin-angiotensin system (RAS), on hypoxia-induced retinal neovascularization and its underlying mechanisms. In vivo, the C57BL/6J mice with oxygen-induced retinopathy (OIR) were injected intravitreally with alamandine (1.0 μmol/kg per eye). In vitro, human retinal microvascular endothelial cells (HRMECs) were utilized to investigate the effects of alamandine (10 μg/mL) on proliferation, apoptosis, migration, and tubular formation under vascular endothelial growth factor (VEGF) stimulation. Single-cell RNA sequencing (scRNA-seq) matrix data from the Gene Expression Omnibus (GEO) database and RAS-related genes from the Molecular Signatures Database (MSigDB) were sourced for subsequent analyses. By integrating scRNA-seq data across multiple species, we identified that RAS-associated endothelial cell populations were highly related to retinal neovascularization. The liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis revealed a significant decrease in alamandine levels in both the serum and retina of OIR mice compared to those in the control group. Next, alamandine ameliorated hypoxia-induced retinal pathological neovascularization and physiologic revascularization in OIR mice. In vitro, alamandine effectively mitigated VEGF-induced proliferation, scratch wound healing, and tube formation of HRMECs primarily by inhibiting the hypoxia-inducible factor-1α (HIF-1α)/VEGF pathway. Further, coincubation with D-Pro⁷ (Mas-related G protein-coupled receptor D (MrgD) antagonist) hindered the beneficial impacts of alamandine on hypoxia-induced pathological angiogenesis both in vivo and in vitro. Our findings suggested that alamandine could mitigate retinal neovascularization by targeting the MrgD-mediated HIF-1α/VEGF pathway, providing a potential therapeutic agent for OIR prevention and treatment.
Animals ; Retinal Neovascularization/prevention & control* ; Mice, Inbred C57BL ; Vascular Endothelial Growth Factor A/metabolism* ; Humans ; Mice ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism* ; Oligopeptides/therapeutic use* ; Signal Transduction/drug effects* ; Cell Proliferation/drug effects* ; Endothelial Cells/drug effects* ; Retinopathy of Prematurity/drug therapy* ; Apoptosis/drug effects* ; Cell Movement/drug effects* ; Renin-Angiotensin System/drug effects* ; Cells, Cultured

OBJECTIVES: To investigate the effect of Didang Decoction-medicated serum on autophagy in high glucose (HG)-induced rat glomerular endothelial cells (RGECs) and explore the pathway that mediates its effect. METHODS: Primary RGECs were isolated and cultured using sequential sieving combined with collagenase digestion, followed by identification using immunofluorescence assay for factor VIII. High glucose medium was used to induce RGECs to simulate a diabetic environment, and the effects of Didang Decoction-medicated serum and 3-MA (an autophagy inhibitor), either alone or in combination, on autophagy of HG-exposed cells were evaluated by observing autophagic vacuoles using monodansylcadaverine (MDC) staining. RT-qPCR and Western blotting were employed to measure mRNA and protein expression levels of Beclin-1, p62, LC3B, p-PI3K, p-Akt, and p-mTOR. RESULTS: Compared with the control cells, the HG-exposed RGECs showed significantly reduced autophagic fluorescence intensity, decreased Beclin-1 mRNA expression, increased p62 mRNA expression, downregulated Beclin-1 protein and LC3-II/I ratio, and upregulated p62, p-PI3K, p-Akt, and p-mTOR protein levels. Didang Decoction-medicated serum significantly enhanced autophagic fluorescence intensity in HG-exposed cells, increased Beclin-1 mRNA expression, decreased p62 mRNA expression, upregulated Beclin-1 protein, and downregulated p62, p-PI3K, p-Akt, and p-mTOR protein levels. CONCLUSIONS Didang Decoction-medicated serum enhances autophagy in HG-exposed RGECs by regulating the PI3K/Akt/mTOR signaling pathway, which sheds light on a new therapeutic strategy for diabetic nephropathy.
Animals ; Autophagy/drug effects* ; Signal Transduction/drug effects* ; Rats ; TOR Serine-Threonine Kinases/metabolism* ; Drugs, Chinese Herbal/pharmacology* ; Proto-Oncogene Proteins c-akt/metabolism* ; Endothelial Cells/metabolism* ; Phosphatidylinositol 3-Kinases/metabolism* ; Glucose ; Cells, Cultured ; Kidney Glomerulus/cytology* ; Rats, Sprague-Dawley

OBJECTIVES: To investigate the antioxidative mechanism of snake venom-derived protein C activator (PCA) in mitigating vascular endothelial cell injury. METHODS: Human umbilical vein endothelial cells (HUVECs) were cultured in DMEM containing 1.0 g/L D-glucose and exposed to hypoxia (1% O₂) for 6 h followed by reoxygenation for 2 h to establish a cell model of oxygen-glucose deprivation/reoxygenation (OGD/R). The cell model was treated with 2 μg/mL PCA alone or in combination with 2-ME2 (a HIF-1α inhibitor) or DMOG (a HIF-1α stabilizer), and intracellular production of reactive oxygen species (ROS) and protein expression levels of HIF-1α, BNIP3, and Beclin-1 were detected using DCFH-DA fluorescence probe, flow cytometry, and Western blotting. The OGD/R cell model was transfected with a BNIP3-specific siRNA or a scrambled control sequence prior to PCA treatment, and the changes in protein expressions of HIF-1α, BNIP3 and Beclin-1 and intracellular ROS production were examined. RESULTS: In the OGD/R cell model, PCA treatment significantly upregulated HIF-1α, BNIP3 and Beclin-1 expressions and reduced ROS production. The effects of PCA were obviously attenuated by co-treatment with 2-ME2 but augmented by treatment with DMOG (a HIF-1α stabilizer). In the cell model with BNIP3 knockdown, PCA treatment increased BNIP3 expression and decreased ROS production without causing significant changes in HIF-1α expression. Compared with HUVECs with PCA treatment only, the cells with BNIP3 knockdown prior to PCA treatment showed significantly lower Beclin-1 expression and higher ROS levels. CONCLUSIONS Snake venom PCA alleviates OGD/R-induced endothelial cell injury by upregulating HIF-1α/BNIP3 signaling to suppress ROS generation, suggesting its potential as a therapeutic agent against oxidative stress in vascular pathologies.
Humans ; Reactive Oxygen Species/metabolism* ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism* ; Human Umbilical Vein Endothelial Cells/drug effects* ; Membrane Proteins/metabolism* ; Proto-Oncogene Proteins/metabolism* ; Up-Regulation ; Cell Hypoxia ; Cells, Cultured ; Snake Venoms/chemistry* ; Beclin-1

OBJECTIVES: To investigate the effects of Naoluo Xintong Decoction (NLXTD) on proliferation of rat brain microvascular endothelial cells (BMECs) after oxygen-glucose deprivation/reoxygenation (OGD/R) injury and role of the HIF-1α/VEGF pathway in mediating its effect. METHODS: Using a BMEC model of OGD/R, we tested the effects of 10% NLXTD-medicated rat serum, alone or in combination with 2ME2 or 10% NAKL, on cell proliferation, migration, tube-forming ability and permeability using CCK-8 assay, Transwell chamber assay, tube formation assay and permeability assay. Cellular expressions of VEGF and Notch were detected using ELISA and laser confocal immunofluorescence analysis, and the expressions of HIF-1α, VEGFR2, Notch1, ERK and P-ERK1/2 proteins were detected with Western blotting. RESULTS: OGD/R injury significantly decreased viability of BMECs. NLXTD treatment of the cells with OGD/R could significantly promoted cell proliferation, migration and tube formation ability, but these effects were strongly attenuated by application of 2ME2. NLXTD treatment also significantly increased the percentages of VEGF- and Notch-positive cells in the cell models and obviously enhanced the expression levels of HIF-1α, VEGFR2, Notch1 and P-ERK1/2. CONCLUSIONS NLXTD promotes proliferation, migration, and tube formation of rat BMECs after OGD/R injury possibly by activating the HIF-1α/VEGF signaling pathway.
Animals ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism* ; Drugs, Chinese Herbal/pharmacology* ; Vascular Endothelial Growth Factor A/metabolism* ; Endothelial Cells/metabolism* ; Rats ; Cell Proliferation/drug effects* ; Signal Transduction/drug effects* ; Glucose ; Brain/blood supply* ; Cells, Cultured ; Rats, Sprague-Dawley ; Vascular Endothelial Growth Factor Receptor-2/metabolism* ; Oxygen/metabolism* ; Cell Hypoxia

OBJECTIVES: To explore the mechanism by which astragaloside IV (AS-IV) alleviates D-galactose (D-GAL)-induced senescence in human umbilical vein endothelial cells (HUVECs). METHODS: Cultured HUVECs were treated with D-GAL (40 g/L), AS-IV (200 μmol/L), D-GAL+AS-IV, or D-GAL+AS-IV+MTK458 (a mitochondrial autophagy agonist, 25 μmol/L) for 48 h, and the changes in cell proliferation, migration, and angiogenesis capacity were evaluated. Cell apoptosis, reactive oxygen species (ROS) levels, mitochondrial membrane potential, and expressions of autophagy-related proteins (LC3-II/LC3-I) and PINK1/Parkin pathway proteins in the treated cells were detected. RESULTS: AS-IV treatment significantly reduced the inhibitory effect of D-GAL on HUVEC viability, effectively alleviated D-GAL-induced impairment of tube-forming ability, and promoted angiogenesis and migration ability of the cells. AS-IV also significantly reduced the rate of D-GAL-induced HUVECs positive for senescence-associated β-galactosidase (SA-β-Gal) staining and inhibited the expression of senescence-related genes P21 and P53. AS-IV restored mitochondrial membrane potential and reduced intracellular ROS levels in D-GAL-induced HUVECs, and inhibited the fusion of autophagosomes and lysosomes to prevent the completion of autophagic flux. In HUVECs treated with both D-GAL and AS-IV, the application MTK458 significantly increased the number of yellow spots and enhanced the expressions of P21, P53, PINK1, Parkin, LC3, and Beclin proteins. CONCLUSIONS AS-IV alleviates D-GAL-induced endothelial cell senescence by inhibiting the PINK1/Parkin pathway to regulate mitochondrial autophagy.
Humans ; Human Umbilical Vein Endothelial Cells/drug effects* ; Cellular Senescence/drug effects* ; Autophagy/drug effects* ; Saponins/pharmacology* ; Ubiquitin-Protein Ligases/metabolism* ; Mitochondria/drug effects* ; Triterpenes/pharmacology* ; Protein Kinases/metabolism* ; Galactose/pharmacology* ; Reactive Oxygen Species/metabolism* ; Signal Transduction/drug effects* ; Cells, Cultured ; Apoptosis/drug effects* ; Membrane Potential, Mitochondrial ; Cell Proliferation/drug effects*

Diabetic retinopathy, a prevalent and vision-threatening microvascular complication of diabetes mellitus, is the leading cause of blindness among middle-aged and elderly individuals. Natural diterpenoids isolated from Siegesbeckia pubescens demonstrate potent anti-inflammatory properties. This study aimed to identify novel bioactive diterpenoids from S. pubescens and investigate their effects on oxidative stress and inflammatory responses in diabetic retinopathy, both in vitro and in vivo. Three new ent-pimarane-type diterpenoids (1-3) and six known compounds (4-9) were isolated from the aerial parts of S. pubescens. Their structures were elucidated through spectroscopic data interpretation, and absolute configurations were determined by comparing calculated and experimental electronic circular dichroism (ECD) spectra. Among these compounds, 14β,16-epoxy-ent-3β,15α,19-trihydroxypimar-7-ene (5) exhibited the most potent protective effect against high glucose and interleukin-1β (IL-1β)-stimulated human retinal endothelial cells. Mechanistically, compound 5 promoted endothelial cell survival while ameliorating oxidative stress and inflammatory response in diabetic retinopathy, both in vivo and in vitro. These findings not only suggest that diterpenoids such as compound 5 are important anti-inflammatory constituents in S. pubescens, but also indicate that compound 5 may serve as a lead compound for preventing or treating vascular complications associated with diabetic retinopathy.
Diabetic Retinopathy/metabolism* ; Humans ; Oxidative Stress/drug effects* ; Animals ; Diterpenes, Kaurane/administration & dosage* ; Asteraceae/chemistry* ; Male ; Endothelial Cells/drug effects* ; Abietanes/administration & dosage* ; Molecular Structure ; Mice ; Anti-Inflammatory Agents/chemistry* ; Plant Extracts/chemistry* ; Mice, Inbred C57BL

This study aims to explore the synergistic effects of the main components in salvianolic acids for Injection(SAFI) on key pathological events in cerebral ischemia, elucidating the pharmacological characteristics of SAFI in neuroprotection. Two major pathological gene modules related to endothelial injury and neuroinflammation in cerebral ischemia were mined from single-cell data. According to the topological distance calculated in network medicine, potential synergistic component combinations of SAFI were screened out. The results showed that the combination of caffeic acid and salvianolic acid B scored the highest in addressing both endothelial injury and neuroinflammation, demonstrating potential synergistic effects. The cell experiments confirmed that the combination of these two components at a ratio of 1∶1 significantly protected brain microvascular endothelial cells(bEnd.3) from oxygen-glucose deprivation/reoxygenation(OGD/R)-induced reperfusion injury and effectively suppressed lipopolysaccharide(LPS)-induced neuroinflammatory responses in microglial cells(BV-2). This study provides a new method for uncovering synergistic effects among active components in traditional Chinese medicine(TCM) and offers novel insights into the multi-component, multi-target acting mechanisms of TCM.
Brain Ischemia/metabolism* ; Neuroprotective Agents/pharmacology* ; Animals ; Drugs, Chinese Herbal/administration & dosage* ; Benzofurans/pharmacology* ; Mice ; Drug Synergism ; Caffeic Acids/pharmacology* ; Polyphenols/pharmacology* ; Humans ; Alkenes/pharmacology* ; Endothelial Cells/drug effects* ; Depsides

Ginsenoside Rg_2(GRg2) is a triterpenoid compound found in Panax notoginseng. This study explored its effects and mechanisms on diabetic retinopathy and angiogenesis. The study employed endothelial cell models induced by glucose or vascular endothelial growth factor(VEGF), the chorioallantoic membrane(CAM) model, the oxygen-induced retinopathy(OIR) mouse model, and the db/db mouse model to evaluate the therapeutic effects of GRg2 on diabetic retinopathy and angiogenesis. Transwell assays and endothelial tube formation experiments were conducted to assess cell migration and tube formation, while vascular area measurements were applied to detect angiogenesis. The impact of GRg2 on the retinal structure and function of db/db mice was evaluated through retinal thickness and electroretinogram(ERG) analyses. The study investigated the mechanisms of GRg2 by analyzing the activation of Yes-associated protein(YAP) and Toll-like receptors(TLRs) pathways. The results indicated that GRg2 significantly reduced cell migration numbers and tube formation lengths in vitro. In the CAM model, GRg2 exhibited a dose-dependent decrease in the vascular area ratio. In the OIR model, GRg2 notably decreased the avascular and neovascular areas, ameliorating retinal structural disarray. In the db/db mouse model, GRg2 increased the total retinal thickness and enhanced the amplitudes of the a-wave, b-wave, and oscillatory potentials(OPs) in the ERG, improving retinal structural disarray. Transcriptomic analysis revealed that the TLR signaling pathway was significantly down-regulated following YAP knockdown, with PCR results consistent with the transcriptome sequencing findings. Concurrently, GRg2 downregulated the expression of Toll-like receptor 4(TLR4), TNF receptor-associated factor 6(TRAF6), and nuclear factor-kappaB(NF-κB) proteins in high-glucose-induced endothelial cells. Collectively, GRg2 inhibits cell migration and tube formation and significantly reduces angiogenesis in CAM and OIR models, improving retinal structure and function in db/db mice, with its pharmacological mechanism likely involving the down-regulation of YAP expression.
Animals ; Ginsenosides/pharmacology* ; Diabetic Retinopathy/physiopathology* ; Mice ; YAP-Signaling Proteins ; Humans ; Male ; Signal Transduction/drug effects* ; Cell Movement/drug effects* ; Adaptor Proteins, Signal Transducing/genetics* ; Mice, Inbred C57BL ; Neovascularization, Pathologic/metabolism* ; Drugs, Chinese Herbal/administration & dosage* ; Panax notoginseng/chemistry* ; Endothelial Cells/metabolism* ; Transcription Factors/genetics* ; Angiogenesis

This article investigated the effect and mechanism of salidroside(SAL) on the expression of adhesion molecules in oxidized low-density lipoprotein(oxLDL)-induced mouse aortic endothelial cell(MAEC). The oxLDL-induced endothelial cell injury model was constructed, and the safe concentration and action time of SAL were screened. The cells were divided into control group, oxLDL group, low and high concentration groups of SAL, and ferrostatin-1(Fer-1) group. The cell viability was detected by CCK-8 assay; lactate dehydrogenase(LDH) leakage was measured by colorimetry; the expression of intercellular adhesion molecule 1(ICAM-1) and recombinant vascular cell adhesion molecule 1(VCAM-1) were detected by immunofluorescence; Fe~(2+),glutathione(GSH),malondialdehyde(MDA),and 4-hydroxynonenal(4-HNE) levels were detected by kit method; reactive oxygen species(ROS) was detected by DCFH-DA probe; the levels of glutathione peroxidase 4(GPX4),silent mating type information regulation 2 homolog 1(SIRT1), and nuclear factor erythroid 2-related factor 2(Nrf2) were determined by using Western blot. The inhibitors of Nrf2 and SIRT1 were used, and endothelial cell were divided into control group, oxLDL group, SAL group, ML385 group(Nrf2 inhibitor), and EX527 group(SIRT1 inhibitor). The ultrastructure of mitochondria was observed by electron microscope; mitochondrial membrane potential(MMP) was detected by flowcytometry; the expressions of SIRT1,Nrf2,solute carrier family 7 member 11(SLC7A11),GPX4,ferroportin 1(FPN1),ferritin heavy chain 1(FTH1),ICAM-1, and VCAM-1 were detected by Western blot. The results showed that similar to Fer-1,low and high concentrations of SAL could improve cell viability, inhibit LDH release and the expression of ICAM-1 and VCAM-1 in oxLDL-induced endothelial cells(P<0.05 or P<0.01). It was related to increase in GSH level, decrease in Fe~(2+),ROS,MDA, and 4-HNE level, and up-regulation of SIRT1,Nrf2, and GPX4 expression to inhibit ferroptosis(P<0.05 or P<0.01). The intervention effect of high concentration SAL was the most significant. ML385 and EX527 could partially offset the protection of SAL on mitochondrial structure and MMP and reverse the ability of SAL to up-regulate the expression of SIRT1,Nrf2,SLC7A11,GPX4,FPN1, and FTH1 and down-regulate the expression of ICAM-1 and VCAM-1(P<0.05 or P<0.01).To sum up, SAL could reduce the expression of ICAM-1 and VCAM-1 in oxLDL-induced endothelial cell, which may relate to activation of SLC7A11/GPX4 antioxidant signaling pathway mediated by SITR1/Nrf2, up-regulation of FPN1 and FTH1 expression, and inhibition of ferroptosis.
Sirtuin 1/genetics* ; Animals ; Ferroptosis/drug effects* ; Lipoproteins, LDL/metabolism* ; NF-E2-Related Factor 2/genetics* ; Mice ; Endothelial Cells/cytology* ; Glucosides/pharmacology* ; Phenols/pharmacology* ; Cell Adhesion Molecules/genetics* ; Reactive Oxygen Species/metabolism* ; Intercellular Adhesion Molecule-1/genetics* ; Vascular Cell Adhesion Molecule-1/genetics* ; Cell Survival/drug effects*

This study elucidates the mechanism of Rhodiolae Crenulatae Radix et Rhizoma(RCRR) in protecting brain microvascular endothelial cells from oxygen-glucose deprivation(OGD) injury and reveals the modern pharmacological mechanism of RCRR's traditional use in nourishing Qi and promoting blood circulation to protect endothelial cells. The scratch assay was employed to assess the migratory capacity of endothelial cells. Immunofluorescence and Western blot techniques were employed to assess the protein expression of tight junction proteins zonula occludens-1(ZO-1), occludin, claudin-5, and proteins of the phosphoinositide 3-kinase(PI3K)/protein kinase B(AKT)/glycogen synthase kinase-3beta(GSK3β) pathway. The results demonstrated that 63 bioactive components and 125 potential core targets of RCRR were identified from the ETCM, TCMBank, and SwissTargetPrediction databases, as well as from the literature. A total of 1 708 brain microvascular endothelial cell-related targets were identified from the GeneCards and OMIM databases, and 52 targets were obtained by intersecting drug components with cell targets. The protein-protein interaction(PPI) network analysis revealed that AKT1, epidermal growth factor receptor(EGFR), matrix metalloproteinase 9(MMP9), estrogen receptor 1(ESR1), proto-oncogene tyrosine-protein kinase(SRC), peroxisome proliferator-activated receptor gamma(PPARG), GSK3β, and matrix metalloproteinase 2(MMP2) were considered hub genes. The KEGG enrichment analysis identified the PI3K/AKT pathway as the primary signaling pathway. Cell experiments demonstrated that RCRR-containing serum could enhance the migratory capacity of brain microvascular endothelial cells and the expression of tight junction proteins following OGD injury, which may be associated with the downregulation of the PI3K/AKT/GSK3β pathway. This study elucidates the pharmacological mechanism of RCRR in protecting brain microvascular endothelial cells through network pharmacology, characterized by multiple components and targets. These findings were validated through in vitro experiments and provide important ideas and references for further research into the molecular mechanisms of RCRR in protecting brain microvascular endothelial cells.
Endothelial Cells/cytology* ; Glycogen Synthase Kinase 3 beta/genetics* ; Proto-Oncogene Proteins c-akt/genetics* ; Drugs, Chinese Herbal/pharmacology* ; Phosphatidylinositol 3-Kinases/genetics* ; Signal Transduction/drug effects* ; Brain/metabolism* ; Humans ; Animals ; Rhizome/chemistry* ; Microvessels/metabolism* ; Brain Ischemia/drug therapy*