Meniscus injuries are widespread and the available treatments do not offer enough healing potential. Here, we provide critical support for using pigs as a biological model for meniscal degeneration and the development of cutting-edge therapies in orthopedics. We present a single-cell transcriptome atlas of the meniscus, consisting of cell clusters corresponding to four major cell types: chondrocytes, endothelial cells, smooth muscle cells, and immune cells. Five distinct chondrocyte subclusters (CH0‒CH4) were annotated, of which only one was widespread in both the red and white zones, indicating a major difference in the cellular makeup of the zones. Subclusters distinct to the white zone appear responsible for cartilage-specific matrix deposition and protection against adverse microenvironmental factors, while those in the red zone exhibit characteristics of mesenchymal stem cells and are more likely to proliferate and migrate. Additionally, they induce remodeling actions in other chondrocyte subclusters and promote the proliferation and maturation of endothelial cells, inducing healing and vascularization processes. Considering that they have substantial remodeling capabilities, these subclusters should be of great interest for tissue engineering studies. We also show that the cellular makeup of the pig meniscus is comparable to that of humans, which supports the use of pigs as a model in orthopedic therapy development.
Animals ; Swine ; Chondrocytes/physiology* ; Single-Cell Analysis ; Meniscus/blood supply* ; Endothelial Cells/cytology* ; Transcriptome ; Mesenchymal Stem Cells/cytology* ; Neovascularization, Physiologic ; Cell Proliferation

OBJECTIVES: The use of stem cells is a promising strategy for seizure treatment owing to their unique characteristics. We investigated the role of endothelial progenitor cells (EPCs) in a pentylenetetrazole (PTZ)‍-induced rat seizure model. A selected panel of long noncoding RNAs (lncRNAs), which maintain an elaborate balance in brain neural regulatory networks as well as the autophagy pathway, was also targeted. METHODS: The impact of intravenously administered EPCs on PTZ-induced kindling in rats was evaluated by measuring the expression of neuronal damage markers, neurotrophic factors, and relevant lncRNA genes. Rat behavior was assessed using Y-maze test and open field test (OFT). RESULTS: EPCs mitigated seizure-associated neurological damage and reversed PTZ-induced working memory and locomotor activity deficits, as evidenced by improved performance in the Y-maze test and OFT. EPC treatment reversed the downregulation of the expression of the lncRNAs Evf2, Pnky, Dlx1, APF, HOTAIR, and FLJ11812. EPCs also boosted vascular endothelial growth factor (VEGF) expression. The ameliorative effect achieved by EPCs was comparable to that produced by valproate. CONCLUSIONS These findings indicate that EPCs ameliorate kindling epileptic seizures and their associated abnormalities and that the effect of EPCs may be mediated via the upregulation of certain regulatory lncRNAs.
Animals ; Pentylenetetrazole ; RNA, Long Noncoding ; Seizures/therapy* ; Rats ; Male ; Endothelial Progenitor Cells/transplantation* ; Rats, Sprague-Dawley ; Kindling, Neurologic ; Vascular Endothelial Growth Factor A/metabolism* ; Disease Models, Animal

Bone repair remains an important target in tissue engineering, making the development of bioactive scaffolds for effective bone defect repair a critical objective. In this study, β-tricalcium phosphate (β-TCP) scaffolds incorporated with processed pyritum decoction (PPD) were fabricated using three-dimensional (3D) printing-assisted freeze-casting. The produced composite scaffolds were evaluated for their mechanical strength, physicochemical properties, biocompatibility, in vitro pro-angiogenic activity, and in vivo efficacy in repairing rabbit femoral defects. They not only demonstrated excellent physicochemical properties, enhanced mechanical strength, and good biosafety but also significantly promoted the proliferation, migration, and aggregation of pro-angiogenic human umbilical vein endothelial cells (HUVECs). In vivo studies revealed that all scaffold groups facilitated osteogenesis at the bone defect site, with the β-TCP scaffolds loaded with PPD markedly enhancing the expression of neurogenic locus Notch homolog protein 1 (Notch1), vascular endothelial growth factor (VEGF), bone morphogenetic protein-2 (BMP-2), and osteopontin (OPN). Overall, the scaffolds developed in this study exhibited strong angiogenic and osteogenic capabilities both in vitro and in vivo. The incorporation of PPD notably promoted the angiogenic-osteogenic coupling, thereby accelerating bone repair, which suggests that PPD is a promising material for bone repair and that the PPD/β-TCP scaffolds hold great potential as a bone graft alternative.
Calcium Phosphates/chemistry* ; Animals ; Bone Regeneration ; Rabbits ; Tissue Scaffolds ; Printing, Three-Dimensional ; Humans ; Human Umbilical Vein Endothelial Cells ; Neovascularization, Physiologic ; Osteogenesis ; Tissue Engineering/methods* ; Biomimetic Materials ; Cell Proliferation ; Angiogenesis

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 role of apelin in regulating proliferation, migration and angiogenesis of bladder cancer cells and the possible regulatory mechanism. METHODS: GEO database was used to screen the differentially expressed genes in bladder cancer tissues and cells. Bladder cancer and paired adjacent tissues were collected from 60 patients for analysis of apelin expressions in relation to clinicopathological parameters. In cultured bladder cancer J82 cells and human umbilical vein endothelial cells (HUVECs), the effects of transfection with an apelin-overexpressing plasmid or specific siRNAs targeting apelin, fibroblast growth factor 2 (FGF2) and fibroblast growth factor receptor 1 (FGFR1) on proliferation and migration of J82 cells and tube formation in HUVECs were examined using plate cloning assay, Transwell assay, and angiogenesis assay; the changes in FGF2 expression and FGFR1 phosphorylation were detected using Western blotting. RESULTS: The expression level of apelin was significantly higher in bladder cancer tissues than adjacent tissues, and bladder cancer cell lines (T24 and J82) also expressed higher mRNA and protein levels of apelin than SV-HUC-1 cells. Apelin expression level in bladder cancer tissues was correlated with tumor invasion, distant metastasis and advanced TNM stages. Apelin knockdown significantly suppressed proliferation and migration of J82 cells and decreased the total angiogenic length of HUVECs. In contrast, apelin overexpression significantly promoted proliferation and migration and enhanced FGFR1 phosphorylation in J82 cells, and increased the total angiogenesis length in HUVECs, but this effects were effectively mitigated by transfection of the cells with FGF2 siRNA or FGFR1 siRNA. CONCLUSIONS High expression of apelin promotes J82 cell proliferation and migration and HUVEC angiogenesis by promoting activation of the FGF2/FGFR1 pathway.
Humans ; Urinary Bladder Neoplasms/blood supply* ; Receptor, Fibroblast Growth Factor, Type 1/metabolism* ; Cell Proliferation ; Cell Movement ; Fibroblast Growth Factor 2/metabolism* ; Neovascularization, Pathologic ; Human Umbilical Vein Endothelial Cells ; Cell Line, Tumor ; Signal Transduction ; Apelin ; Intercellular Signaling Peptides and Proteins/genetics* ; Female ; Male ; Angiogenesis

OBJECTIVES: To investigate the structural changes of rat thoracic aorta and changes in expression levels of Bmal1 and cyclins in thoracic aorta endothelial cells following heat stress. METHODS: Twenty male SD rats were randomized equally into control group and heat stress group. After exposure to 32 ℃ for 2 weeks in the latter group, the rats were examined for histopathological changes and Bmal1 expression in the thoracic aorta using HE staining and immunohistochemistry. In the cell experiments, cultured rat thoracic aortic endothelial cells (RTAECs) were incubated at 40 ℃ for 12 h with or without prior transfection with a Bmal1-specific small interfering RNA (si-Bmal1) or a negative sequence. In both rat thoracic aorta and RTAECs, the expressions of Bmal1, the cell cycle proteins CDK1, CDK4, CDK6, and cyclin B1, and apoptosis-related proteins Bax and Bcl-2 were detected using Western blotting. TUNEL staining was used to detect cell apoptosis in rat thoracic aorta, and the changes in cell cycle distribution and apoptosis in RTAECs were analyzed with flow cytometry. RESULTS: Compared with the control rats, the rats exposed to heat stress showed significantly increased blood pressures and lowered heart rate with elastic fiber disruption and increased expressions of Bmal1, cyclin B1 and CDK1 in the thoracic aorta (P<0.05). In cultured RTAECs, heat stress caused significant increase of Bmal1, cyclin B1 and CDK1 protein expression levels, which were obviously lowered in cells with prior si-Bmal1 transfection. Bmal1 knockdown also inhibited heat stress-induced increase of apoptosis in RTAECs as evidenced by decreased expression of Bax and increased expression of Bcl-2. CONCLUSIONS Heat stress upregulates Bmal1 expression and causes alterations in expressions of cyclins to trigger apoptosis of rat thoracic aorta endothelial cells, which can be partly alleviated by suppressing Bmal1 expression.
Animals ; ARNTL Transcription Factors/genetics* ; Male ; Aorta, Thoracic/metabolism* ; Rats ; Rats, Sprague-Dawley ; Endothelial Cells/metabolism* ; Apoptosis ; Cells, Cultured ; Heat-Shock Response ; Cyclin B1/metabolism* ; CDC2 Protein Kinase/metabolism* ; Cyclins/metabolism* ; RNA, Small Interfering ; bcl-2-Associated X Protein/metabolism*

OBJECTIVES: To investigate the role of sphingosine-1-phosphate receptor 5 (S1PR5) in modulating barrier function of mouse brain microvascular endothelial cells with oxygen-glucose deprivation and reoxygenation (OGD/R). METHODS: Mouse brain microvascular endothelial cells (bEnd.3) were exposed to OGD/R to induce barrier dysfunction following treatment with S1PR5-specific agonist A971432 or lentivirus-mediated transfection with a S1PR5-specific siRNA, a S1PR5-overexpressing plasmid, or their respective negative control sequences. The changes in viability and endothelial barrier permeability of the treated cells were evaluated with CCK-8 assay and FITC-dextran permeability assay; the levels of intracellular reactive oxygen species (ROS) and localization and expression levels of the proteins related with barrier function and oxidative stress were detected using immunofluorescence staining, DCFH-DA probe and Western blotting. RESULTS: S1PR5 activation obviously enhanced viability of bEnd.3 cells exposed to OGD/R (P<0.0001). Both activation and overexpression of S1PR5 reduced FITC-dextran leakage, while S1PR5 knockdown significantly increased FITC-dextran leakage in the exposed bEnd.3 cells. Activation and overexpression of S1PR5 both increased the cellular expressions of the barrier proteins ZO-1 and occludin, while S1PR5 knockdown produced the opposite effect. In cells exposed to OGD/R, ROS production was significantly reduced by S1PR5 activation and overexpression but increased following S1PR5 knockdown. Overexpression of S1PR5 obviously increased the expressions of the antioxidant proteins Nrf2, HO-1 and SOD2 in the exposed cells. CONCLUSIONS S1PR5 activation and overexpression significantly improve cell viability and reduce permeability of a mouse brain microvascular endothelial cell model of OGD/R, the mechanism of which may involve the reduction in ROS production and upregulation of the antioxidant proteins.
Animals ; Mice ; Oxidative Stress ; Endothelial Cells/cytology* ; Brain/blood supply* ; Reactive Oxygen Species/metabolism* ; Receptors, Lysosphingolipid/metabolism* ; Sphingosine-1-Phosphate Receptors ; Blood-Brain Barrier/metabolism* ; Glucose ; Cell Line ; Oxygen/metabolism* ; NF-E2-Related Factor 2/metabolism*

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