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 evaluate the effect of eye acupuncture on neural function and angiogenesis of ischemic cerebral tissue in rats, and explore the roles of METTL3-mediated m⁶A methylation and the HIF-1α/VEGF-A signal axis in mediating this effect. METHODS: Fifty SD rats were randomized into normal control group, sham-operated group, model group, eye acupuncture group and DMOG (a HIF-1α agonist) group. Rat models of cerebral ischemia/reperfusion injury (CIRI) were established using a modified thread thrombus method, and the changes in neurological deficits of the rats after interventions were evaluated. TTC and Nissl staining were used to examine the changes in infarction size and neuronal injury, and cerebral angiogenesis was detected by double-immunofluorescence staining. m⁶A methylation modification level in the brain tissue was detected by ELISA, and RT-qPCR and Western blotting were used to detect the mRNA and protein expressions of METTL3 and HIF-1α/VEGF-A. RESULTS: Compared with the control and sham-operated rats, the CIRI rats had significantly higher neurological deficit scores with larger cerebral infarction area, a greater number of CD31- and EDU-positive new vessels, higher expression levels of HIF-1α and VEGF-A, reduced number of Nissl bodies and m6A methylation level, and lowered METTL3 protein and mRNA expressions. All these changes were significantly improved by interventions with eye acupuncture after modeling or intraperitoneal injections of DMOG for 7 consecutive days prior to modeling, and the effects of the two interventions were similar. CONCLUSIONS Eye acupuncture can improve neurological deficits in CIRI rat models possibly by promoting cortical angiogenesis via upregulating METTL3-mediated m⁶A methylation and regulating the HIF-1α/VEGF-A signal axis.
Animals ; Rats, Sprague-Dawley ; Methyltransferases/metabolism* ; Reperfusion Injury/physiopathology* ; Methylation ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism* ; Rats ; Vascular Endothelial Growth Factor A/metabolism* ; Brain Ischemia/metabolism* ; Acupuncture Therapy ; Male ; Up-Regulation ; Neovascularization, Physiologic ; Angiogenesis ; Adenosine/analogs & derivatives*

OBJECTIVES: To investigate the mechanism by which Guijianyu ameliorates podocyte injury in a mouse model of diabetic kidney disease (DKD) induced by advanced glycation endproducts (AGEs). METHODS: Sixty db/db mouse models of DKD were randomized equally into 5 groups for treatment with saline, Guijianyu extract at 3 doses or irbesartan for 12 weeks, and the changes in renal pathology and structure were observed using transmission electron microscopy, and the expressions of related genes and key proteins were detected using RT-qPCR and immunohistochemistry. In cultured MPC-5 cells incubated with 50 mg/L AGEs-BSA for 24 h, the effect of different concentrations of Guijianyu extract on cell viability was examined with CCK-8 assay; Western blotting was performed to detect the protein expressions of RAGE, VEGFA, TNF-α, NF-κB(p65), IL-6 and caspase-3, and the mRNA expressions of RAGE, NF-κB (p65), VEGFA and IL-6 were detected with RT-qPCR. RESULTS: In mouse models of DKD, treatment with high-dose Guijianyu extract significantly reduced renal expressions of RAGE, VEGFA, NF-κB(p65), and IL-6 proteins and the mRNA expressions of RAGE, NF-κB, and IL-6. In MPC-5 cells, exposure to AGEs significantly reduced cell viability and increased the protein expressions of RAGE, NF‑κB (p65), VEGFA, TNF-α, IL-6 and caspase-3 (P<0.05) and mRNA expressions of RAGE, NF-κB (p65), VEGFA, and IL-6. Treatment with Guijianyu extract obviously improved cell viability and reduced the expressions of RAGE, NF-κB(p65), VEGFA, TNF-α, IL-6, and caspase-3. Furthermore, Guijianyu extract effectively reversed RAGE agonist-induced elevation of protein expressions of RAGE, VEGFA, TNF-α, IL-6, and caspase-3 and mRNA expressions of RAGE, NF-κB (p65), IL-6, and VEGFA in MPC-5 cells. CONCLUSIONS Guijianyu extract ameliorates AGEs-induced mouse renal podocyte injury in DKD by inhibiting the activation of AGEs-RAGE signaling pathway and reducing the expressions of pro-inflammatory cytokines and vascular endothelial growth factors.
Animals ; Glycation End Products, Advanced ; Drugs, Chinese Herbal/pharmacology* ; Mice ; Signal Transduction/drug effects* ; Podocytes/pathology* ; Diabetic Nephropathies/drug therapy* ; Receptor for Advanced Glycation End Products ; Vascular Endothelial Growth Factor A/metabolism* ; Interleukin-6/metabolism* ; Male

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

The angiogenic response is essential for the repair of ischemic brain tissue. Integrin α6 (Itga6) expression has been shown to increase under hypoxic conditions and is expressed exclusively in vascular structures; however, its role in post-ischemic angiogenesis remains poorly understood. In this study, we demonstrate that mice with endothelial cell-specific knockout of Itga6 exhibit reduced neovascularization, reduced pericyte coverage on microvessels, and accelerated breakdown of microvascular integrity in the peri-infarct area. In vitro, endothelial cells with ITGA6 knockdown display reduced proliferation, migration, and tube-formation. Mechanistically, we demonstrated that ITGA6 regulates post-stroke angiogenesis through the PI3K/Akt-eNOS-VEGFA axis. Importantly, the specific overexpression of Itga6 in endothelial cells significantly enhanced neovascularization and enhanced the integrity of microvessels, leading to improved functional recovery. Our results suggest that endothelial cell Itga6 plays a crucial role in key steps of post-stroke angiogenesis, and may represent a promising therapeutic target for promoting recovery after stroke.
Animals ; Nitric Oxide Synthase Type III/metabolism* ; Mice ; Proto-Oncogene Proteins c-akt/metabolism* ; Integrin alpha6/genetics* ; Endothelial Cells/metabolism* ; Phosphatidylinositol 3-Kinases/metabolism* ; Stroke/pathology* ; Vascular Remodeling/physiology* ; Vascular Endothelial Growth Factor A/metabolism* ; Mice, Knockout ; Signal Transduction/physiology* ; Mice, Inbred C57BL ; Male ; Neovascularization, Physiologic/physiology*

Intrauterine adhesion(IUA) is a common gynecological disease that is difficult to treat, and there is a lack of specific effective drugs and measures to prevent endometrial fibrosis. In this study, the mechanism of endometrial oxidative stress and fibrosis regulation was studied in an IUA rat model constructed by Bushen Huoxue Formula intervention of mechanical injury combined with infection. A total of 72 SPF SD female rats aged 8-10 weeks were randomly divided into blank control group, model control group, low-dose, medium-dose, and high-dose groups of Bushen Huoxue Formula, and estrogen groups. The rats in the estrous cycle of the model control group and the positive control group were simulated with surgical injury and infection, and the sham operation group was treated with on-off abdominal treatment. After successful modeling, the model control group was administered intragastrically with purified water of 15 μL·g~(-1) every day. The low-dose group was administered intragastrically with Bushen Huoxue Formula of 7.8 g·kg~(-1); the medium-dose group was administered intragastrically with Bushen Huoxue Formula of 15.6 g·kg~(-1), and the high-dose group was administered intragastrically with Bushen Huoxue Formula of 31.2 g·kg~(-1). The estrogen group was administered intragastrically with estradiol valerate of 4.2 mg·kg~(-1). After continuous intervention for 28 days, all rats were deprived of water and killed to collect blood and tissue. Hematoxylin-eosin(HE) staining calculated the number of uterine glands; Masson staining calculated the area of uterine collagen fibers. Combined with HE and Masson staining, semi-quantitative scores were performed on the degree of endometrial fibrosis. Immunohistochemistry was performed to detect the vascular endothelial growth factor(VEGF), stromal cell-derived factor-1(SDF-1), and transforming growth factor-β1(TGF-β1) expression in rats' uterine tissue. Enzyme-linked immunosorbent assay(ELISA) dected angiopoietin 1(IFN-γ), interleukin-1α(IL-1α), TGF-β1, tumor necrosis factor-α(TNF-α), collagen type Ⅳ(Ⅳ-Col), leukemia inhibitory factor(LIF), superoxide dismutase(SOD)、glutathione peroxidase(GSH-Px);The mRNA expressions of Smad2, Smad3, adisintegrin and metalloproteinase(ADAM17) and TGF-β1 were determined by qPCR. Notch and ADAM17 protein expression in rat uterus were determined by Western blot. The results showed that the area of uterine fibrosis was significantly reduced and the conditions of edema and adhesion were effectively alleviated after high-dose intervention of Bushen Huoxue Formula. The levels of inflammatory factors and Ⅳ-Col were significantly decreased, and the levels of LIF and antioxidant enzymes were significantly increased. The mRNA expressions of Smad2, Smad3, ADAM17 and TGF-β1 were significantly down-regulated. Immunohistochemical results showed that Bushen Huoxu Formula could effectively increase the positive expression of SDF-1 and reduce the positive expression of VEGF and TGF-β1. Western blot results showed that the protein expressions of Notch and ADAM17 in high-dose, medium-dose and low-dose of Bushen Huoxu Formula groups were significantly down-regulated in a dose-dependent manner. These results suggest that Bushen Huoxue Formula may inhibit fibrosis process through ADAM17/Notch signaling pathway, suggesting that Bushen Huoxuet Formula is one of the potential therapeutic methods for IUA.
Animals ; Female ; Drugs, Chinese Herbal/administration & dosage* ; Rats, Sprague-Dawley ; Endometrium/pathology* ; Rats ; Fibrosis/metabolism* ; Oxidative Stress/drug effects* ; Humans ; Uterine Diseases/genetics* ; Vascular Endothelial Growth Factor A/genetics*

This study aims to explore whether Naoxintong Capsules improve multiple cerebral infarctions and myocardial injury via promoting angiogenesis, thereby exerting a simultaneous treatment effect on both the brain and heart. Male SD rats were randomly divided into six groups: sham-operated group, model group, high-dose, medium-dose, and low-dose groups of Naoxintong Capsules(440, 220, and 110 mg·kg~(-1)), and nimodipine group(10.8 mg·kg~(-1)). Rat models of multiple cerebral infarctions were established by injecting autologous thrombus, and samples were collected and tested seven days after modeling. Evaluations included multiple cerebral infarction model assessments, neurological function scores, grip strength tests, and rotarod tests, so as to evaluate neuromotor functions. Morphological structures of brain and heart tissue were observed using hematoxylin-eosin(HE) staining, Nissl staining, and Masson staining. Network pharmacology was employed to screen the mechanisms of Naoxintong Capsules in improving multiple cerebral infarctions and myocardial injury. Neuronal and myocardial cell ultrastructures were observed using transmission electron microscopy. Apoptosis rate in brain neuronal cells was detected by TdT-mediated dUTP nick end labeling(TUNEL) staining, and reactive oxygen species(ROS) levels in myocardial cells were measured. Immunofluorescence was used to detect the expression of platelet endothelial cell adhesion molecule-1(CD31), antigen identified by monoclonal antibody Ki67(Ki67), hematopoietic progenitor cell antigen CD34(CD34), and hypoxia inducible factor-1α(HIF-1α) in brain and myocardial tissue. Western blot, and real-time quantitative polymerase chain reaction(RT-qPCR) were used to detect the expression of HIF-1α, vascular endothelial growth factor(VEGF), vascular endothelial growth factor receptor 2(VEGFR2), sarcoma(Src), basic fibroblast growth factor(bFGF), angiopoietin-1(Ang-1), and TEK receptor tyrosine kinase(Tie-2). Compared with the model group, the medium-dose group of Naoxintong Capsules showed significantly lower neurological function scores, increased grip strength, and prolonged time on the rotarod. Pathological damage in brain and heart tissue was reduced, with increased and more orderly arranged mitochondria in neurons and cardiomyocytes. Apoptosis in brain neuronal cells was decreased, and ROS levels in cardiomyocytes were reduced. The microvascular density and endothelial cells of new blood vessels in brain and heart tissue increased, with increased overlapping regions of CD31 and Ki67 expression. The relative protein and mRNA expression levels of HIF-1α, VEGF, VEGFR2, Src, Ang-1, Tie-2, and bFGF were elevated in brain tissue and myocardial tissue. Naoxintong Capsules may improve multiple cerebral infarctions and myocardial injury by mediating HIF-1α/VEGF expression to promote angiogenesis.
Animals ; Male ; Drugs, Chinese Herbal/administration & dosage* ; Rats, Sprague-Dawley ; Rats ; Cerebral Infarction/genetics* ; Hypoxia-Inducible Factor 1, alpha Subunit/genetics* ; Vascular Endothelial Growth Factor A/genetics* ; Capsules ; Signal Transduction/drug effects* ; Humans ; Brain/metabolism* ; Myocardium/metabolism* ; Apoptosis/drug effects*

OBJECTIVE: To evaluate the effect of biodegradable magnesium alloy materials in promoting tendon-bone healing during rotator cuff tear repair and to investigate their potential underlying biological mechanisms. METHODS: Forty-eight 8-week-old Sprague Dawley rats were taken and randomly divided into groups A, B, and C. Rotator cuff tear models were created and repaired using magnesium alloy sutures in group A and Vicryl Plus 4-0 absorbable sutures in group B, while only subcutaneous incisions and sutures were performed in group C. Organ samples of groups A and B were taken for HE staining at 1 and 2 weeks after operation to evaluate the safety of magnesium alloy, and specimens from the supraspinatus tendon and proximal humerus were harvested at 2, 4, 8, and 12 weeks after operation. The specimens were observed macroscopically at 4 and 12 weeks after operation. Biomechanical tests were performed at 4, 8, and 12 weeks to test the ultimate load and stiffness of the healing sites in groups A and B. At 2, 4, and 12 weeks, the specimens were subjected to the following tests: Micro-CT to evaluate the formation of bone tunnels in groups A and B, HE staining and Masson staining to observe the regeneration of fibrocartilage at the tendon-bone interface after decalcification and sectioning, and Goldner trichrome staining to evaluate the calcification. Immunohistochemical staining was performed to detect the expressions of angiogenic factors, including vascular endothelial growth factor (VEGF) and bone morphogenetic protein 2 (BMP-2), as well as osteogenic factors at the tendon-bone interface. Additionally, immunofluorescence staining was used to examine the expressions of Arginase 1 and Integrin beta-2 to assess M1 and M2 macrophage polarization at the tendon-bone interface. The role of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway in tendon-bone healing was further analyzed using real-time fluorescence quantitative PCR. RESULTS: Analysis of visceral sections revealed that magnesium ions released during the degradation of magnesium alloys did not cause significant toxic effects on organs such as the heart, liver, spleen, lungs, and kidneys, indicating good biosafety. Histological analysis further demonstrated that fibrocartilage regeneration at the tendon-bone interface in group A occurred earlier, and the amount of fibrocartilage was significantly greater compared to group B, suggesting a positive effect of magnesium alloy material on tendon-bone interface repair. Additionally, Micro-CT analysis results revealed that bone tunnel formation occurred more rapidly in group A compared to group B, further supporting the beneficial effect of magnesium alloy on bone healing. Biomechanical testing showed that the ultimate load in group A was consistently higher than in group B, and the stiffness of group A was also greater than that of group B at 4 weeks, indicating stronger tissue-carrying capacity following tendon-bone interface repair and highlighting the potential of magnesium alloy in enhancing tendon-bone healing. Immunohistochemical staining results indicated that the expressions of VEGF and BMP-2 were significantly upregulated during the early stages of healing, suggesting that magnesium alloy effectively promoted angiogenesis and bone formation, thereby accelerating the tendon-bone healing process. Immunofluorescence staining further revealed that magnesium ions exerted significant anti-inflammatory effects by regulating macrophage polarization, promoting their shift toward the M2 phenotype. Real-time fluorescence quantitative PCR results demonstrated that magnesium ions could facilitate tendon-bone healing by modulating the PI3K/AKT signaling pathway. CONCLUSION Biodegradable magnesium alloy material accelerated fibrocartilage regeneration and calcification at the tendon-bone interface in rat rotator cuff tear repair by regulating the PI3K/AKT signaling pathway, thereby significantly enhancing tendon-bone healing.
Animals ; Rotator Cuff Injuries/metabolism* ; Rats, Sprague-Dawley ; Signal Transduction ; Wound Healing/drug effects* ; Alloys/pharmacology* ; Rats ; Proto-Oncogene Proteins c-akt/metabolism* ; Rotator Cuff/metabolism* ; Macrophages/metabolism* ; Magnesium/pharmacology* ; Phosphatidylinositol 3-Kinases/metabolism* ; Vascular Endothelial Growth Factor A/metabolism* ; Male ; Biocompatible Materials ; Bone Morphogenetic Protein 2/metabolism*

OBJECTIVE: To investigate the effects of combined platelet-rich plasma (PRP) and arterial supercharging technique on the survival rate and functional restoration of cross-body region skin flaps in rabbits. METHODS: Twelve healthy 6-month-old New Zealand White rabbits were randomly assigned to 4 groups ( n=3): sham group, PRP group, anastomosis group, and combined treatment group. An axial skin flap with an area of 12 cm×6 cm on the inner side of the hind limbs of all animals were prepared, with the saphenous artery as the main blood supply. Following the ligation of both the proximal and distal ends of the saphenous artery across all groups, the sham group received no further intervention, the PRP group was subjected to PRP injection, the anastomosis group underwent in situ end-to-end anastomosis of the distal saphenous artery, and the combined treatment group received both in situ distal saphenous artery anastomosis and PRP administration. Flap survival was evaluated and recorded on postoperative days 1, 3, and 7, with survival rates calculated accordingly. On day 7, flap tissue samples were harvested for HE staining to assess basal tissue morphology. Additionally, immunohistochemical staining was conducted to detect the expression of α-smooth muscle actin (α-SMA), vascular endothelial growth factor (VEGF), and CD31 in the flap tissues. RESULTS: At postoperative day 1, no significant difference in flap survival rates were observed among the 4 groups ( P>0.05). At day 3, the PRP group showed no significant difference compared to the sham group ( P>0.05); however, both the anastomosis and combined treatment groups exhibited significantly higher survival rates than the sham group ( P<0.05), the combined treatment group further demonstrated superior survival rates compared to both the PRP and anastomosis groups ( P<0.05). At day 7, the combined treatment group maintained significantly higher survival rates than all other groups ( P<0.05), while both the PRP and anastomosis groups exceeded the sham group ( P<0.05). HE staining at day 7 revealed persistent inflammatory cell infiltration, sheet-like erythrocyte deposition, and disordered collagen fibers in the sham group. The PRP group showed nascent microvessel formation and early collagen reorganization, whereas the anastomosis group displayed mature microvasculature with resolved interstitial edema. The combined treatment group exhibited differentiated microvessels with densely packed collagen bundles. Immunohistochemical analysis at day 7 demonstrated significantly larger relative area percentages of α-SMA, VEGF, and CD31 positive cells in the combined treatment group compared to all other groups ( P<0.05). Both the PRP and anastomosis groups also showed significantly higher values than the sham group ( P<0.05). CONCLUSION The combination of PRP and arterial supercharging techniques significantly enhances flap healing, potentially through mechanisms involving augmented angiogenesis and improved blood supply.
Animals ; Rabbits ; Platelet-Rich Plasma ; Surgical Flaps/blood supply* ; Graft Survival ; Anastomosis, Surgical/methods* ; Ischemia/surgery* ; Arteries/surgery* ; Skin/blood supply* ; Vascular Endothelial Growth Factor A/metabolism* ; Male ; Skin Transplantation/methods*

OBJECTIVE: To investigate the effectiveness and preliminary mechanisms of icariin (ICA) in enhancing the reparative effects of adipose-derived stem cells (ADSCs) on skin radiation damagies in rats. METHODS: Twelve SPF-grade Sprague Dawley rats [body weight (220±10) g] were subjected to a single dose of 10 Gy X-ray irradiation on a 1.5 cm×1.5 cm area of their dorsal skin, with a dose rate of 200 cGy/min to make skin radiation damage model. After successful modelling, the rats were randomly divided into 4 groups ( n=3), and on day 2, the corresponding cells were injected subcutaneously into the irradiated wounds: group A received 0.1 mL of rat ADSCs (1×10 ⁷cells/mL), group B received 0.1 mL of rat ADSCs (1×10 ⁷cells/mL)+1 μmol/L ICA (0.1 mL), group C received 0.1 mL of rat ADSCs (1×10 ⁷cells/mL) pretreated with a hypoxia-inducible factor 2α (HIF-2α) inhibitor+1 μmol/L ICA (0.1 mL), and group D received 0.1 mL of rat ADSCs (1×10 ⁷cells/mL) pretreated with a Notch1 inhibitor+1 μmol/L ICA (0.1 mL). All treatments were administered as single doses. The skin injury in the irradiated areas of the rats was observed continuously from day 1 to day 7 after modelling. On day 28, the rats were sacrificed, and skin tissues from the irradiated areas were harvested for histological examination (HE staining and Masson staining) to assess the repair status and for quantitative collagen content detection. Immunohistochemical staining was performed to detect CD31 expression, while Western blot and real-time fluorescence quantitative PCR (qRT-PCR) were used to measure the protein and mRNA relative expression levels of vascular endothelial growth factor (VEGF), platelet-derived growth factor BB (PDGF-BB), fibroblast growth factor 2 (FGF-2), interleukin 10 (IL-10), transforming growth factor β (TGF-β), HIF-2α, and Notch1, 2, and 3. RESULTS: All groups exhibited skin ulcers and redness after irradiation. On day 3, exudation of tissue fluid was observed in all groups. On day 7, group B showed significantly smaller skin injury areas compared to the other 3 groups. On day 28, histological examination revealed that the epidermis was thickened and the dermal fibers were slightly disordered with occasional inflammatory cell aggregation in group A. In group B, the epidermis appeared more normal, the dermal fibers were more orderly, and there was an increase in new blood vessels without significant inflammatory cell aggregation. In contrast, groups C and D showed significantly increased epidermal thickness, disordered and disrupted dermal fibers. Group B had higher collagen fiber content than the other 3 groups, and group D had lower content than group A, with significant differences ( P<0.05). Immunohistochemical staining showed that group B had significantly higher CD31 expression than the other 3 groups, while groups C and D had lower expression than group A, with significant differences ( P<0.05). Western blot and qRT-PCR results indicated that group B had significantly higher relative expression levels of VEGF, PDGF-BB, FGF-2, IL-10, TGF-β, HIF-2α, and Notch1, 2, and 3 proteins and mRNAs compared to the other 3 groups ( P<0.05). CONCLUSION ICA may enhance the reparative effects of ADSCs on rat skin radiation damage by promoting angiogenesis and reducing inflammatory responses through the HIF-2α-VEGF-Notch signaling pathway.
Animals ; Rats, Sprague-Dawley ; Skin/pathology* ; Rats ; Vascular Endothelial Growth Factor A/genetics* ; Basic Helix-Loop-Helix Transcription Factors/genetics* ; Signal Transduction ; Flavonoids/pharmacology* ; Adipose Tissue/cytology* ; Stem Cells/cytology* ; Receptors, Notch/metabolism* ; Radiation Injuries, Experimental/metabolism* ; Wound Healing/drug effects* ; Male