OBJECTIVE: To investigate the effects and mechanisms of hydroxysafflor yellow A (HSYA) on replicative senescence in human umbilical cord mesenchymal stem cells (hUC-MSCs). METHODS: hUC-MSCs were cultured to construct a replicative senescence model through continuous amplification in vitro. Cells at passage 2 served as the control group, while cells at passage 10 were designated as the senescence group. The senescent cells were cultured in a culture medium containing HSYA. Cell viability was detected by the CCK-8 assay, and cell confluence was analyzed using the Incucyte S3 live-cell analysis system. The optimal concentration and time point were determined and utilized for subsequent experiments. Senescent cells were pretreated with 0.01 mg/ml HSYA, and the proportion of senescence-associated β-galactosidase (SA-β-gal) positive cells was detected to assess the senescence state. The relative telomere length was detected by qPCR. Reactive oxygen species (ROS) levels were measured using the fluorescent probe DCFH-DA. Mitochondrial membrane potential was assessed by JC-1 staining. The expression of p53, p16, p21, OCT4, and SOX2 genes was detected by qPCR. The expression of p16, p53, OCT4, and SOX2 proteins was analyzed by Western blot. RESULTS: HSYA significantly decreased the SA-β-gal positive staining rate, inhibited telomere attrition, reduced the ROS accumulation, increased mitochondrial membrane potential in senescent cells. Additionally, HSYA downregulated the expression of p53 and p16, and upregulated the expression of OCT4. HSYA decreased p16 protein level and increased OCT4 and SOX2 protein levels. CONCLUSION HSYA may ameliorate replicative senescence in hUC-MSCs by modulating the p53 and p16 signaling pathways and suppressing oxidative stress.
Humans ; Mesenchymal Stem Cells/drug effects* ; Cellular Senescence/drug effects* ; Chalcone/pharmacology* ; Oxidative Stress/drug effects* ; Quinones/pharmacology* ; Umbilical Cord/cytology* ; Reactive Oxygen Species/metabolism* ; Cells, Cultured ; Cyclin-Dependent Kinase Inhibitor p16/metabolism* ; Tumor Suppressor Protein p53/metabolism* ; Membrane Potential, Mitochondrial ; Cell Proliferation

OBJECTIVE: To investigate the Wnt signaling pathway and miRNAs mechanism of extracts of Plastrum Testudinis (PT) in the treatment of osteoporosis (OP). METHODS: Thirty female Sprague Dawley rats were randomly divided into 5 groups by random number table method, including sham group, ovariectomized group (OVX), ovariectomized groups treated with high-, medium-, and low-dose PT (160, 80, 40 mg/kg per day, respectively), with 6 rats in each group. Except for the sham group, the other rats underwent bilateral ovariectomy to simulate OP and received PT by oral gavage for 10 consecutive weeks. After treatment, bone mineral density was measured by dual-energy X-ray absorptiometry; bone microstructure was analyzed by micro-computed tomography and hematoxylin and eosin staining; and the expressions of osteogenic differentiation-related factors were detected by immunochemistry, Western blot, and quantitative polymerase chain reaction. In addition, Dickkopf-1 (Dkk-1) was used to inhibit the Wnt signaling pathway in bone marrow mesenchymal stem cells (BMSCs) and miRNA overexpression was used to evaluate the effect of miR-214 on the osteogenic differentiation of BMSCs. Subsequently, PT extract was used to rescue the effects of Dkk-1 and miR-214, and its impacts on the osteogenic differentiation-related factors of BMSCs were evaluated. RESULTS: PT-M and PT-L significantly reduced the weight gain in OVX rats (P<0.05). PT also regulated the bone mass and bone microarchitecture of the femur in OVX rats, and increased the expressions of bone formation-related factors including alkaline phosphatase, bone morphogenetic protein type 2, collagen type I alpha 1, and runt-related transcription factor 2 when compared with the OVX group (P<0.05 or P<0.01). Meanwhile, different doses of PT significantly rescued the inhibition of Wnt signaling pathway-related factors in OVX rats, and increased the mRNA or protein expressions of Wnt3a, β-catenin, glycogen synthase kinase-3β, and low-density lipoprotein receptor-related protein 5 (P<0.05 or P<0.01). PT stimulated the osteogenic differentiation of BMSCs inhibited by Dkk-1 and activated the Wnt signaling pathway. In addition, the expression of miR-214 was decreased in OVX rats (P<0.01), and it was negatively correlated with the osteogenic differentiation of BMSCs (P<0.01). MiR-214 mimic inhibited Wnt signaling pathway in BMSCs (P<0.05 or P<0.01). Conversely, PT effectively counteracted the effect of miR-214 mimic, thereby activating the Wnt signaling pathway and stimulating osteogenic differentiation in BMSCs (P<0.05 or P<0.01). CONCLUSION PT stimulates bone formation in OVX rats through β-catenin-mediated Wnt signaling pathway, which may be related to inhibiting miR-214 in BMSCs.
Animals ; MicroRNAs/genetics* ; Female ; Rats, Sprague-Dawley ; Wnt Signaling Pathway/genetics* ; Osteogenesis/genetics* ; Mesenchymal Stem Cells/cytology* ; Cell Differentiation/drug effects* ; Bone Density/drug effects* ; Ovariectomy ; Osteoporosis/drug therapy* ; beta Catenin/metabolism* ; Rats ; Intercellular Signaling Peptides and Proteins/metabolism* ; Drugs, Chinese Herbal/pharmacology*

OBJECTIVES: To explore the mechanism by which Tougu Xiaotong Capsule (TXC) promotes chondrogenic differentiation and cartilage repair in mice with osteoarthritis (OA). METHODS: Fifty 8-week-old male C57BL mice were randomly divided into normal control group, cartilage damage (induced by subchondral ring-shaped drilling) model group and TXC treatment groups at low, moderate and high doses (184, 368 and 736 mg/kg, respectively). Saline (in normal control and model groups) and TXC were administered after modeling by daily gavage for 6 consecutive weeks. The changes of cartilage damage in the mice were assessed by measuring thermal withdrawal latency (TWL) and mechanical withdrawal threshold (MWT) and using micro-CT, modified safranine O and fast green staining, HE staining, and qPCR. Primary cultures of mouse synovial mesenchymal stem cells (SMSCs) with lentivirus vector transfection for interfering CXCL12, TXC treatment, or both for 24 h were examined for chondrogenic differentiation using immunofluorescence staining, scratch assay, immunocytochemistry, and Western blotting. RESULTS: In mouse models with cartilage damage, TXC treatment at the moderate dose significantly alleviated joint pain, promoted cartilage repair, and upregulated the mRNA expression levels of CXCL12, GDF5, collagen II, aggrecan, Comp and Sox9 in the cartilage tissue. In primary mouse SMSCs, CXCL12 knockdown resulted in significant reduction of GDF5 protein expression, migration ability and Sox9 protein expression, and these changes were obviously reversed by TXC treatment. CONCLUSIONS TXC promotes chondrogenic differentiation of mouse SMSCs to promote repair of cartilage damage in mice by activating the CXCL12/GDF5 pathway.
Animals ; Drugs, Chinese Herbal/therapeutic use* ; Osteoarthritis/metabolism* ; Male ; Growth Differentiation Factor 5/metabolism* ; Mice, Inbred C57BL ; Mice ; Chemokine CXCL12/metabolism* ; Signal Transduction/drug effects* ; Cell Differentiation/drug effects* ; Cartilage, Articular/drug effects* ; Mesenchymal Stem Cells/cytology*

Regenerating periodontal bone defect surrounding periodontal tissue is crucial for orthodontic or dental implant treatment. The declined osteogenic ability of periodontal ligament stem cells (PDLSCs) induced by inflammation stimulus contributes to reduced capacity to regenerate periodontal bone, which brings about a huge challenge for treating periodontitis. Here, inspired by the adhesive property of mussels, we have created adhesive and mineralized hydrogel microspheres loaded with traditional compound cordycepin (MMS-CY). MMS-CY could adhere to the surface of alveolar bone, then promote the migration capacity of PDLSCs and thus recruit them to inflammatory periodontal tissues. Furthermore, MMS-CY rescued the impaired osteogenesis and ligament-forming capacity of PDLSCs, which were suppressed by the inflammation stimulus. Moreover, MMS-CY also displayed the excellent inhibitory effect on the osteoclastic activity. Mechanistically, MMS-CY inhibited the premature senescence induced by the inflammation stimulus through the nuclear factor erythroid 2-related factor (NRF2) pathway and reducing the DNA injury. Utilizing in vivo rat periodontitis model, MMS-CY was demonstrated to enhance the periodontal bone regeneration by improving osteogenesis and inhibiting the osteoclastic activity. Altogether, our study indicated that the multi-pronged approach is promising to promote the periodontal bone regeneration in periodontitis condition by reducing the inflammation-induced stem cell senescence and maintaining bone homeostasis.
Animals ; Bone Regeneration/drug effects* ; Rats ; Periodontal Ligament/cytology* ; Microspheres ; NF-E2-Related Factor 2 ; Hydrogels ; Periodontitis/therapy* ; Osteogenesis/drug effects* ; Disease Models, Animal ; Stem Cells ; Male ; Rats, Sprague-Dawley ; Humans

The ambiguity of etiology makes temporomandibular joint osteoarthritis (TMJOA) "difficult-to-treat". Emerging evidence underscores the therapeutic promise of exosomes in osteoarthritis management. Nonetheless, challenges such as low yields and insignificant efficacy of current exosome therapies necessitate significant advances. Addressing lower strontium (Sr) levels in arthritic synovial microenvironment, we studied the effect of Sr element on exosomes and miRNA selectively loading in synovial mesenchymal stem cells (SMSCs). Here, we developed an optimized system that boosts the yield of SMSC-derived exosomes (SMSC-EXOs) and improves their miRNA profiles with an elevated proportion of beneficial miRNAs, while reducing harmful ones by pretreating SMSCs with Sr. Compared to untreated SMSC-EXOs, Sr-pretreated SMSC-derived exosomes (Sr-SMSC-EXOs) demonstrated superior therapeutic efficacy by mitigating chondrocyte ferroptosis and reducing osteoclast-mediated joint pain in TMJOA. Our results illustrate Alix's crucial role in Sr-triggered miRNA loading, identifying miR-143-3p as a key anti-TMJOA exosomal component. Interestingly, this system is specifically oriented towards synovium-derived stem cells. The insight into trace element-driven, site-specific miRNA selectively loading in SMSC-EXOs proposes a promising therapeutic enhancement strategy for TMJOA.
MicroRNAs/metabolism* ; Mesenchymal Stem Cells/drug effects* ; Osteoarthritis/drug therapy* ; Exosomes/drug effects* ; Strontium/pharmacology* ; Synovial Membrane/cytology* ; Humans ; Animals ; Temporomandibular Joint Disorders/therapy* ; Temporomandibular Joint

OBJECTIVES: To explore the promoting effect of ginsenoside Rb3 (Rb3) on osteogenesis in periodontitis environment, and to explain its mechanism. METHODS: Human periodontal ligament stem cells (hPDLSCs) were cultured by tissue block method and identified by flow cytometry. Cell counting kit-8 (CCK8) method and calcein acetoxymethyl ester/propidium iodide staining were used to detect the effect of Rb3 on the viability of hPDLSCs cells. In vitro cell experiments were divided into control group, 10 μg/mL lipopolysaccharides (LPS) group, 10 μg/mL LPS+100 μmol/L Rb3 group and 10 μg/mL LPS+200 μmol/L Rb3 group. Alkaline phosphatase (ALP) staining was used to detect the ALP activity of hPDLSCs in each group after osteogenesis induction. The expression of hPDLSCs interleukin-6 (IL-6), interleukin-8 (IL-8), runt-related transcription factor 2 (RUNX2) and transforming growth factor-β (TGF-β)genes in each group after osteogenesis was detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR) method. Western blot was used to detect the protein expression of hPDLSCs phosphorrylated extracellular signal-regulated kinase (p-ERK) in each group. Sprague-Dawley rats were randomly divided into the control group, ligation group and ligation+Rb3 group. The left molar-maxillary tissue was subjected to micro-computed tomography (micro-CT) scanning. After the scanning, the left molar-maxilla was made into periodontal tissue sections. Hematoxylin-eosin (HE) staining was used to detect the infiltration and loss of adhesion of inflammatory cells. Masson staining was used to detect the destruction of gingival collagen fibers. Immunofluorescence staining was used to detect the protein expression of RUNX2 and p-ERK. The expression of TGF-β in rat gingival tissue was detected by qRT-PCR. The protein expression of IL-6 in peripheral serum of rats was detected by enzyme-linked immunosorbent assay (ELISA). Flow cytometry was used to detect the proportion of Treg cells in rat heart blood. The experimental data were statistically analyzed by Graph Pad Prism10.1.2 software. RESULTS: Rb3 had no effect on the cell activity of hPDLSCs. The results of qRT-PCR and ALP staining showed that Rb3 could inhibit the gene expression of IL-6 and IL-8 in inflammatory hPDLSCs, promote TGF-β gene and promote the osteogenic differentiation of inflammatory hPDLSCs. Western blot showed that Rb3 inhibited the protein expression of inflammatory hPDLSCs p-ERK. The results from micro-CT, Masson staining, and HE staining demonstrated that Rb3 promotes alveolar bone formation in rats with periodontitis, while simultaneously inhibiting the destruction of periodontal fibrous tissue, reducing attachment loss, and suppressing inflammatory cell infiltration. The results of flow cytometry showed that Rb3 could promote the differentiation of Treg cells in peripheral blood of periodontitis rats. The results of ELISA and qRT-PCR showed that Rb3 could inhibit the protein expression of IL-6 and promote the gene expression of TGF-β in periodontitis rats. Immunofluorescence results showed that Rb3 could promote the protein expression of RUNX2 and inhibit the protein expression of p-ERK in periodontitis rats. CONCLUSIONS Rb3 can reduce the inflammatory reaction of periodontal tissues in periodontitis rats, and promote the osteogenic differentiation of hPDLSCs by regulating p-ERK pathways.
Animals ; Ginsenosides/pharmacology* ; Osteogenesis/drug effects* ; Periodontitis/metabolism* ; Rats ; Periodontal Ligament/cytology* ; Humans ; Core Binding Factor Alpha 1 Subunit/metabolism* ; Stem Cells/drug effects* ; Interleukin-6/metabolism* ; Rats, Sprague-Dawley ; Interleukin-8/metabolism* ; Cells, Cultured ; MAP Kinase Signaling System/drug effects* ; Transforming Growth Factor beta/metabolism* ; Signal Transduction ; Male ; Phosphorylation ; Lipopolysaccharides ; Extracellular Signal-Regulated MAP Kinases/metabolism* ; Alkaline Phosphatase/metabolism*

OBJECTIVES: Investigating the protective effect of naringenin (NAR) on the osteogenic potential of human periodontal ligament stem cells (hPDLSCs) under oxidative stress and its related mechanisms. METHODS: The oxidative damage model of hPDLSCs was established using hydrogen peroxide (H₂O₂) andthe hPDLSCs were treated with different concentrations of NAR and 0.5 μmol/L forkhead box protein O-1 (FOXO1) inhibitor AS1842856. After that, the cell counting kit-8 (CCK8) was used to determine the optimal concentrations of H₂O₂ and NAR. The alkaline phosphatase (ALP) staining and real time fluorescent quantitative reverse transcription polymerase chain reaction (qRT-PCR) were employed to assess the expression of ALP, runt-related transcription factor 2 (RUNX2) and osteocalcin (OCN) in hPDLSCs of each group. The enzyme-linked immunosorbent assay (ELISA) and 2',7'-dichlorofluorescin diacetate (DCFH-DA) staining were utilized to evaluate the expression of reactive oxygen species (ROS), malondialdehyde (MDA) and lactate dehydrogenase (LDH) in hPDLSCs. Meanwhile, qRT-PCR and western blot were used to detect the expression levels of FOXO1 and β-catenin, both are pathway related genes and proteins. RESULTS: H₂O₂ exposure led to an increase in oxidative damage in hPDLSCs, characterized by a rise in intracellular ROS levels and increased expression of MDA and LDH (P<0.05). At the same time, the osteogenic differentiation ability of hPDLSCs decreased, as evidenced by lighter ALP staining and reduced expression levels of osteogenic differentiation-related genes ALP, RUNX2 and OCN (P<0.05). Co-treatment with NAR alleviated the oxidative damage in hPDLSCs, enhanced their antioxidant capacity, and restored their osteogenic ability. The FOXO1 inhibitor AS1842856 downregulated the expression of β-catenin (P<0.05) and significantly diminished both the antioxidant effect of NAR and its ability to restore osteogenesis (P<0.05). CONCLUSIONS NAR can enhance the antioxidant capacity of hPDLSCs by activating the FOXO1/β-catenin signaling pathway within hPDLSCs, thereby mitigating oxidative stress damage and alleviating the loss of osteogenic capacity.
Humans ; Oxidative Stress/drug effects* ; Periodontal Ligament/cytology* ; Hydrogen Peroxide ; Forkhead Box Protein O1/metabolism* ; Stem Cells/cytology* ; Flavanones/pharmacology* ; beta Catenin/metabolism* ; Osteogenesis/drug effects* ; Signal Transduction ; Core Binding Factor Alpha 1 Subunit/metabolism* ; Alkaline Phosphatase/metabolism* ; Osteocalcin/metabolism* ; Cells, Cultured ; Cell Differentiation/drug effects*

To investigate the mechanism of Qitu Erzhi Decoction(QTEZ) in ameliorating chemotherapy-induced myelosuppression and the focus of its decomposed formulae on the effects of hematopoietic cells of the three lineages, respectively. Ultra performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry(UPLC-Q-TOF-MS) was used to identify the components of QTEZ intestinal absorption liquid and obtain the target sites, which were intersected with chemotherapy-induced myelosuppression targets collected from several databases, including OMIM, and an interaction network was established based on network pharmacology for Gene Ontology(GO) functional analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway analysis. Hematopoietic stem cells of mice were taken after intraperitoneal injection of 5-fluorouracil for myelosuppression modeling and randomly divided into the model group, Qitu Erzhi group, Astragali Radix-Angelicae Sinensis Radix group, Ligustri Lucidi Fructus-Ecliptae Herba group, Psoraleae Fructus-Cuscutae Semen group, and positive drug group, which were given the corresponding traditional Chinese medicine intestinal absorption liquid and the positive drug granulocyte colony-stimulating factor, respectively. The normal hematopoietic stem cells were taken as the control group and were given the intervention of normal saline. The proliferation of hematopoietic progenitor cells of three lineages was observed by flow cytometry, and the cell cycle and colony formation assay were observed. Western blot was used to verify the effect of QTEZ on the pathway proteins including phosphoinositide 3-kinase(PI3K), phosphorylated PI3K(p-PI3K), protein kinase B(AKT), and phosphorylated AKT(p-AKT). RT-qPCR and Western blot were used to detect the effects of QTEZ on cell cycle-related targets such as CDK inhibitor 1(P21), cyclin D1(CCND1), and cyclin-dependent kinase 4(CDK4). The results showed that a total of 158 components were identified by QTEZ, and 375 component and disease intersecting targets were obtained, 21 core components and 40 core targets were obtained after constructing the network, and GO and KEGG enrichment showed signaling pathways such as PI3K/AKT. QTEZ and its decomposed formulae could promote the 5-fluorouracil-blocked cell cycle to resume operation, and all of them had different degrees of restoration effects on the set of colonies, among which QTEZ had the best restoration effect, and the Astragali Radix-Angelicae Sinensis Radix group had a focused effect on colony forming unit-erythrocyte. Western blot results indicated that there was no significant difference in the expression levels of pathway proteins among the groups. RT-qPCR and Western blot results showed that QTEZ could down-regulate P21 and up-regulate the protein and mRNA expression of CDK4 and CCND1. In conclusion, QTEZ and its decomposed formulas can exert a protective effect on hematopoietic stem cells with 5-fluorouracil-induced myelosuppression by promoting the normal operation of the cell cycle and colony formation, and the mechanism may be related to the down-regulation of the cell cycle-related targets of P21 and the up-regulation of CDK4 and CCND1. In addition, Astragali Radix-Angelicae Sinensis Radix can have a targeted protective effect on erythrocytes.
Animals ; Drugs, Chinese Herbal/chemistry* ; Network Pharmacology ; Mice ; Fluorouracil/adverse effects* ; Male ; Antineoplastic Agents/adverse effects* ; Hematopoietic Stem Cells/cytology* ; Humans ; Signal Transduction/drug effects*

OBJECTIVE: To investigate the effects of sodium valproate (VPA) in inhibiting Erastin-induced ferroptosis in bone marrow mesenchymal stem cells (BMSCs) and its underlying mechanisms. METHODS: BMSCs were isolated from bone marrow of 8-week-old Spragur Dawley rats and identified [cell surface antigens CD90, CD44, and CD45 were analyzed by flow cytometry, and osteogenic and adipogenic differentiation abilities were assessed by alizarin red S (ARS) and oil red O staining, respectively]. Cells of passage 3 were used for the Erastin-induced ferroptosis model, with different concentrations of VPA for intervention. The optimal drug concentration was determined using the cell counting kit 8 assay. The experiment was divided into 4 groups: group A, cells were cultured in osteogenic induction medium for 24 hours; group B, cells were cultured in osteogenic induction medium containing optimal concentration Erastin for 24 hours; group C, cells were cultured in osteogenic induction medium containing optimal concentration Erastin and VPA for 24 hours; group D, cells were cultured in osteogenic induction medium containing optimal concentration Erastin and VPA, and 8 μmol/L EX527 for 24 hours. The mitochondrial state of the cells was evaluated, including the levels of malondialdehyde (MDA), glutathione (GSH), and reactive oxygen species (ROS). Osteogenic capacity was assessed by alkaline phosphatase (ALP) activity and ARS staining. Western blot analysis was performed to detect the expressions of osteogenic-related proteins [Runt-related transcription factor 2 (RUNX2) and osteopontin (OPN)], ferroptosis-related proteins [glutathione peroxidase 4 (GPX4), ferritin heavy chain 1 (FTH1), and solute carrier family 7 member 11 (SLC7A11)], and pathway-related proteins [adenosine monophosphate-activated protein kinase (AMPK) and Sirtuin 1 (SIRT1)]. RESULTS: The cultured cells were identified as BMSCs. VPA inhibited Erastin-induced ferroptosis and the decline of osteogenic ability in BMSCs, acting through the activation of the AMPK/SIRT1 pathway. VPA significantly reduced the levels of ROS and MDA in Erastin-treated BMSCs and significantly increased GSH levels. Additionally, the expression levels of ferroptosis-related proteins (GPX4, FTH1, and SLC7A11) significantly decreased. VPA also upregulated the expressions of osteogenic-related proteins (RUNX2 and OPN), enhanced mineralization and osteogenic differentiation, and increased the expressions of pathway-related proteins (AMPK and SIRT1). These effects could be reversed by the SIRT1 inhibitor EX527. CONCLUSION VPA inhibits ferroptosis in BMSCs through the AMPK/SIRT1 axis and promotes osteogenesis.
Mesenchymal Stem Cells/metabolism* ; Ferroptosis/drug effects* ; Animals ; Valproic Acid/pharmacology* ; Rats ; Rats, Sprague-Dawley ; Sirtuin 1/metabolism* ; Cell Differentiation/drug effects* ; Cells, Cultured ; AMP-Activated Protein Kinases/metabolism* ; Osteogenesis/drug effects* ; Piperazines/pharmacology* ; Bone Marrow Cells/cytology* ; Reactive Oxygen Species/metabolism* ; Signal Transduction/drug effects*

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