1.P4HA1 mediates YAP hydroxylation and accelerates collagen synthesis in temozolomide-resistant glioblastoma.
Xueru LI ; Gangfeng YU ; Xiao ZHONG ; Jiacheng ZHONG ; Xiangyu CHEN ; Qinglong CHEN ; Jinjiang XUE ; Xi YANG ; Xinchun ZHANG ; Yao LING ; Yun XIU ; Yaqi DENG ; Hongda LI ; Wei MO ; Yong ZHU ; Ting ZHANG ; Liangjun QIAO ; Song CHEN ; Fanghui LU
Chinese Medical Journal 2025;138(16):1991-2005
BACKGROUND:
Temozolomide (TMZ) resistance is a significant challenge in treating glioblastoma (GBM). Collagen remodeling has been shown to be a critical factor for therapy resistance in other cancers. This study aimed to investigate the mechanism of TMZ chemoresistance by GBM cells reprogramming collagens.
METHODS:
Key extracellular matrix components, including collagens, were examined in paired primary and recurrent GBM samples as well as in TMZ-treated spontaneous and grafted GBM murine models. Human GBM cell lines (U251, TS667) and mouse primary GBM cells were used for in vitro studies. RNA-sequencing analysis, chromatin immunoprecipitation, immunoprecipitation-mass spectrometry, and co-immunoprecipitation assays were conducted to explore the mechanisms involved in collagen accumulation. A series of in vitro and in vivo experiments were designed to assess the role of the collagen regulators prolyl 4-hydroxylase subunit alpha 1 (P4HA1) and yes-associated protein (YAP) in sensitizing GBM cells to TMZ.
RESULTS:
This study revealed that TMZ exposure significantly elevated collagen type I (COL I) expression in both GBM patients and murine models. Collagen accumulation sustained GBM cell survival under TMZ-induced stress, contributing to enhanced TMZ resistance. Mechanistically, P4HA1 directly binded to and hydroxylated YAP, preventing ubiquitination-mediated YAP degradation. Stabilized YAP robustly drove collagen type I alpha 1 ( COL1A1) transcription, leading to increased collagen deposition. Disruption of the P4HA1-YAP axis effectively reduced COL I deposition, sensitized GBM cells to TMZ, and significantly improved mouse survival.
CONCLUSION
P4HA1 maintained YAP-mediated COL1A1 transcription, leading to collagen accumulation and promoting chemoresistance in GBM.
Temozolomide
;
Humans
;
Glioblastoma/drug therapy*
;
Animals
;
Mice
;
Cell Line, Tumor
;
Drug Resistance, Neoplasm/genetics*
;
YAP-Signaling Proteins
;
Hydroxylation
;
Dacarbazine/pharmacology*
;
Adaptor Proteins, Signal Transducing/metabolism*
;
Transcription Factors/metabolism*
;
Collagen/biosynthesis*
;
Collagen Type I/metabolism*
;
Prolyl Hydroxylases/metabolism*
;
Antineoplastic Agents, Alkylating/therapeutic use*
2.Research progress on pathological changes of glenohumeral capsule in patients with recurrent shoulder anterior dislocation.
Pai CHEN ; Daqiang LIANG ; Bing WU ; Hao LI ; Haifeng LIU ; Zeling LONG ; Yuwei LIU ; Wei LU
Chinese Journal of Reparative and Reconstructive Surgery 2025;39(2):243-249
OBJECTIVE:
To review the research progress of pathological changes of glenohumeral capsule in patients with recurrent shoulder anterior dislocation (RSAD).
METHODS:
The literature on shoulder capsules, both domestic and international, was reviewed. The anatomy, histology, and molecular biology characteristics of the glenohumeral capsule in RSAD patients were summarized.
RESULTS:
Anatomically, the glenohumeral capsule is composed of four distinct parts: the upper, lower, anterior, and posterior sections. The thickness of these sections is uneven, and the stability of the capsule is further enhanced by the presence of the glenohumeral and coracohumeral ligaments. Histologically, the capsule tissue undergoes adaptive changes following RSAD, which improve its ability to withstand stretching and deformation. In the realm of molecular biology, genes associated with the regulation of structure formation, function, and extracellular matrix homeostasis of the shoulder capsule's collagen fibers exhibit varying degrees of expression changes. Specifically, the up-regulation of transforming growth factor β 1 (TGF-β 1), TGF-β receptor 1, lysyl oxidase, and procollagen-lysine, 2-oxoglutarate 5-dioxygenase 1 facilitates the repair of the joint capsule, thereby contributing to the maintenance of shoulder joint stability. Conversely, the up-regulation of collagen type Ⅰ alpha 1 (COL1A1), COL3A1, and COL5A1 is linked to the recurrence of shoulder anterior dislocation, as these changes reflect the joint capsule's response to dislocation. Additionally, the expressions of tenascin C and fibronectin 1 may play a role in the pathological processes occurring during the early stages of RSAD.
CONCLUSION
Glenohumeral capsular laxity is both a consequence of RSAD and a significant factor contributing to its recurrence. While numerous studies have documented alterations in the shoulder capsule following RSAD, further research is necessary to confirm the specific pathological anatomy, histological, and molecular biological changes involved.
Humans
;
Joint Capsule/metabolism*
;
Shoulder Dislocation/metabolism*
;
Recurrence
;
Shoulder Joint/metabolism*
;
Tenascin/metabolism*
;
Transforming Growth Factor beta1/genetics*
;
Collagen Type I/genetics*
;
Extracellular Matrix/metabolism*
3.Research on the mechanism of gentiopicroside preventing macrophage-mediated liver fibrosis by regulating the MIF-SPP1 signaling pathway in hepatic stellate cells.
Jixu WANG ; Yingbin ZHU ; Maoli CHEN ; Yongfeng HAN
Chinese Journal of Cellular and Molecular Immunology 2025;41(7):593-602
Objective To explore the mechanism by which gentiopicroside (GPS) prevents macrophage-mediated hepatic fibrosis by regulating the macrophage migration inhibitory factor (MIF)-secreted phosphoprotein 1 (SPP1) signaling pathway in hepatic stellate cells. Methods LX-2 cells were divided into control group, transforming growth factor β(TGF-β) group, and TGF-β combined with GPS (25, 50, 100, 150 μmol/mL) groups. Cell proliferation was detected by EDU assay, cell invasion was assessed by TranswellTM assay, and the protein expressions of α-smooth muscle actin (α-SMA) and type I collagen (COL1A1) were measured by Western blot. M1-type macrophage-conditioned medium (M1-CM) was used to treat LX-2 cells in the TGF-β group and TGF-β combined with GPS group. The concentrations of inducible nitric oxide synthase (iNOS) and arginase 1 (Arg1) in the cell supernatant, as well as cell proliferation, invasion ability, and the expressions of α-SMA and COL1A1 were detected. Bioinformatics analysis was performed to identify the target intersections of GPS, hepatic fibrosis, and macrophage-related genes. Drug affinity responsive target stability (DARTS) experiments and Western blot were used to verify the regulatory effect of GPS on MIF. Furthermore, LX-2 cells were divided into control group, TGF-β group, TGF-β combined with M2-CM group, TGF-β and oe-NC combined with M2-CM group, and TGF-β and oe-MIF combined with M2-CM group to analyze the concentrations of iNOS and Arg1 in the cell supernatant, as well as changes in cell proliferation, invasion, and the expressions of α-SMA and COL1A1. LX-2 cells were also divided into control group, TGF-β group, TGF-β combined with oe-NC group, TGF-β combined with oe-MIF group, and TGF-β and oe-MIF combined with GPS group to determine the protein expressions of MIF and SPP1 by Western blot. A rat model of hepatic fibrosis was constructed to explore the potential therapeutic effects of GPS on hepatic fibrosis in vivo. Results Compared with the control group, the proliferation and invasion abilities of LX-2 cells in the TGF-β group were increased, and the protein expressions of α-SMA and COL1A1 were enhanced. GPS intervention inhibited the proliferation and invasion of LX-2 cells under TGF-β conditions and reduced the expressions of α-SMA and COL1A1. Compared with the control group, the concentration of iNOS in the cell supernatant of the TGF-β group was upregulated, while the concentration of Arg1 was decreased. M1-CM treatment further increased the concentration of iNOS, decreased the concentration of Arg1, and promoted cell proliferation and invasion, as well as upregulated the expressions of α-SMA and COL1A1 on the basis of TGF-β intervention. However, GPS could reverse the effects of M1-CM intervention. Bioinformatics analysis revealed that MIF was one of the target intersections of GPS, hepatic fibrosis, and macrophage-related genes, and GPS could target and inhibit its expression. Compared with the TGF-β group, after M2-CM intervention, the concentration of iNOS in the cell supernatant decreased, the concentration of Arg1 increased, the proliferation and invasion abilities of LX-2 cells were reduced, and the expressions of α-SMA and COL1A1 were weakened. However, overexpression of MIF reversed the effects of M2-CM intervention. Western blot results showed that compared with the control group, the protein expressions of MIF and SPP1 were enhanced in the TGF-β group. Overexpression of MIF further enhanced the expressions of MIF and SPP1, while GPS intervention inhibited the expressions of MIF and SPP1. In the animal experiment, GPS intervention treatment alleviated liver injury in rats with hepatic fibrosis and inhibited the expressions of MIF and SPP1, as well as α-SMA and COL1A1 in liver tissue. Conclusion GPS may prevent macrophage-mediated hepatic fibrosis by inhibiting the MIF-SPP1 signaling pathway in hepatic stellate cells.
Hepatic Stellate Cells/metabolism*
;
Signal Transduction/drug effects*
;
Macrophage Migration-Inhibitory Factors/genetics*
;
Liver Cirrhosis/prevention & control*
;
Macrophages/drug effects*
;
Iridoid Glucosides/pharmacology*
;
Humans
;
Cell Proliferation/drug effects*
;
Animals
;
Cell Line
;
Collagen Type I/metabolism*
;
Collagen Type I, alpha 1 Chain
;
Intramolecular Oxidoreductases/genetics*
;
Rats
;
Transforming Growth Factor beta/pharmacology*
;
Actins/metabolism*
4.Abnormal collagen deposition mediated by cartilage oligomeric matrix protein in the pathogenesis of oral submucous fibrosis.
Yafei XIONG ; Xuechun LI ; Bincan SUN ; Jie ZHANG ; Xiaoshan WU ; Feng GUO
International Journal of Oral Science 2025;17(1):25-25
Abnormal accumulation of collagen fibrils is a hallmark feature of oral submucous fibrosis (OSF). However, the precise characteristics and underlying mechanisms remain unclear, impeding the advancement of potential therapeutic approaches. Here, we observed that collagen I, the main component of the extracellular matrix, first accumulated in the lamina propria and subsequently in the submucosa of OSF specimens as the disease progressed. Using RNA-seq and Immunofluorescence in OSF specimens, we screened the cartilage oligomeric matrix protein (COMP) responsible for the abnormal collagen accumulation. Genetic COMP deficiency reduced arecoline-stimulated collagen I deposition significantly in vivo. In comparison, both COMP and collagen I were upregulated under arecoline stimulation in wild-type mice. Human oral buccal mucosal fibroblasts (hBMFs) also exhibited increased secretion of COMP and collagen I after stimulation in vitro. COMP knockdown in hBMFs downregulates arecoline-stimulated collagen I secretion. We further demonstrated that hBMFs present heterogeneous responses to arecoline stimulation, of which COMP-positive fibroblasts secrete more collagen I. Since COMP is a molecular bridge with Fibril-associated collagens with Interrupted Triple helices (FACIT) in the collagen network, we further screened and identified collagen XIV, a FACIT member, co-localizing with both COMP and collagen I. Collagen XIV expression increased under arecoline stimulation in wild-type mice, whereas it was hardly expressed in the Comp-/- mice, even with under stimulation. In summary, we found that COMP may mediates abnormal collagen I deposition by functions with collagen XIV during the progression of OSF, suggesting its potential to be targeted in treating OSF.
Oral Submucous Fibrosis/pathology*
;
Cartilage Oligomeric Matrix Protein/genetics*
;
Animals
;
Mice
;
Humans
;
Fibroblasts/metabolism*
;
Collagen Type I/metabolism*
;
Arecoline/pharmacology*
;
Mouth Mucosa/metabolism*
;
Cells, Cultured
;
Fluorescent Antibody Technique
5.Diterpenoids and lignans from fossil Chinese medicinal succinum and their activity against renal fibrosis.
Yefei CHEN ; Yunfei WANG ; Yunyun LIU ; Yongming YAN ; Yongxian CHENG
Chinese Journal of Natural Medicines (English Ed.) 2025;23(7):888-896
Five previously undescribed diterpenoids, named succipenoids D‒H (1‒5), along with four undescribed lignans, named succignans A‒D (6‒9), were isolated from the dichloromethane extract of Chinese medicinal succinum. Compounds 1‒5 were characterized as nor-abietane diterpenoids, while compounds 6‒9 were identified as lignans polymerized from two groups of phenylpropanoid units. The structures of these novel compounds, including their absolute configurations, were determined through spectroscopic and computational methods. Biological assessments of renal fibrosis demonstrated that compounds 6 and 7 effectively reduce the expression of proteins associated with renal fibrosis, including α-smooth muscle actin (α-SMA), collagen I, and fibronectin in transforming growth factor-β1 (TGF-β1) induced normal rat kidney proximal tubular epithelial cells (NRK-52e).
Animals
;
Rats
;
Lignans/isolation & purification*
;
Diterpenes/isolation & purification*
;
Fibrosis/drug therapy*
;
Drugs, Chinese Herbal/pharmacology*
;
Molecular Structure
;
Cell Line
;
Kidney Diseases/pathology*
;
Transforming Growth Factor beta1/genetics*
;
Kidney/metabolism*
;
Actins/genetics*
;
Fibronectins/genetics*
;
Collagen Type I/genetics*
;
Epithelial Cells/metabolism*
6.Effects of Gly mutations N-terminal to the integrin-binding sequence on the structure and function of recombinant collagen.
Fei LI ; Yuxi HOU ; Ben RAO ; Xiaoyan LIU ; Yaping WANG ; Yimin QIU
Chinese Journal of Biotechnology 2025;41(4):1573-1587
Collagen, a vital matrix protein for various tissue and functions in animals, is widely applied in biomaterials. In type Ⅰ collagen, missense mutations of glycine (Gly) in the Gly-Xaa-Yaa triplet of the triple helix are a major cause of osteogenesis imperfecta (OI). Clinical manifestations exhibit marked heterogeneity, spanning a broad disease spectrum from mild skeletal fragility (Type Ⅰ) to severe limb deformities (Type Ⅲ) and perinatal lethal forms (Type Ⅱ). This study utilized recombinant collagen as a model to further elucidate whether Gly→Ala/Val mutations at the N-terminus of the integrin-binding sequence GFPGER affect collagen structure and function, and to explore the underlying mechanisms by which missense mutations impact the biological function of collagen. By introducing Ala and Val substitutions at seven Gly positions N-terminal to the GFPGER sequence, we systematically assessed the effects of these amino acid replacements on the triple-helical structure, thermal stability, integrin-binding ability, and cell adhesion of recombinant collagen. All constructs formed a stable triple-helix structure, with slightly compromised thermal stability. Gly→Val substitutions increased the susceptibility of recombinant collagen to trypsin, which suggested local conformational perturbations in the triple helix. In addition, Gly→Val substitutions significantly reduced the integrin-binding affinity and decreased HT1080 cell adhesion, with the effects stronger than Gly→Ala substitutions. Compared with Gly→Ala substitutions, substitution of Gly with the larger residue Val had enhanced negative effects on the structure and function of recombinant collagen. These findings provide new insights into the molecular mechanisms of osteogenesis imperfecta and offer theoretical references and experimental foundations for the design of collagen sequences and the development of collagen-based biomaterials.
Recombinant Proteins/biosynthesis*
;
Glycine/genetics*
;
Humans
;
Osteogenesis Imperfecta/genetics*
;
Integrins/metabolism*
;
Collagen/metabolism*
;
Collagen Type I/metabolism*
;
Amino Acid Substitution
;
Mutation
;
Mutation, Missense
7.Study on anti-adhesion effect and mechanism of dynamic and static stress stimulation during early healing process of rat Achilles tendon injury.
Jiani WU ; Yingzi JIANG ; Guanyu WANG ; Liliao WANG ; Jie BAO ; Jun WANG
Chinese Journal of Reparative and Reconstructive Surgery 2024;38(11):1391-1398
OBJECTIVE:
To investigate the anti-adhesive effect and underlying mechanism of dynamic and static stress stimulation on the early healing process of rat Achilles tendon injury.
METHODS:
Achilles tendon tissues of 15 male Sprague Dawley (SD) rats aged 4-6 weeks were isolated and cultured by enzyme digestion method. Rat Achilles tendon cells were treated with tumor necrosis factor α to construct the Achilles tendon injury cell model, and dynamic stress stimulation (dynamic group) and static stress stimulation (static group) were applied respectively, while the control group was not treated. Live/dead cell double staining was used to detect cell activity, ELISA assay was used to detect the expression of α smooth muscle actin (α-SMA), and real-time fluorescence quantitative PCR was used to detect the mRNA expression of collagen type Ⅰ (COL1A1), collagen type Ⅲ (COL3A1), and Scleraxis (SCX). Thirty male SD rats aged 4-6 weeks underwent Achilles tendon suture and were randomly divided into dynamic group (treated by dynamic stress stimulation), static group (treated by static stress stimulation), and control group (untreated), with 10 rats in each group. HE staining and scoring were performed to evaluate the healing of Achilles tendon at 8 days after operation. COL1A1 and COL3A1 protein expressions were detected by immunohistochemical staining, α-SMA and SCX protein expressions were detected by Western blot, and maximum tendon breaking force and tendon stiffness were detected by biomechanical stretching test.
RESULTS:
<i>In vitroi> cell experiment, when compared to the static group, the number of living cells in the dynamic group was higher, the expression of α-SMA protein was decreased, the relative expression of COL3A1 mRNA was decreased, and the relative expression of SCX mRNA was increased, and the differences were all significant ( <i>Pi><0.05). In the <i>in vivoi> animal experiment, when compared to the static group, the tendon healing in the dynamic group was better, the HE staining score was lower, the expression of COL1A1 protein was increased, the expression of COL3A1 protein was decreased, the relative expression of SCX protein was increased, the relative expression of α-SMA protein was decreased, and the tendon stiffness was increased, the differences were all significant ( <i>Pi><0.05).
CONCLUSION
Compared with static stress stimulation, the dynamic stress stimulation improves the fibrosis of the scar tissue of the rat Achilles tendon, promote the recovery of the biomechanical property of the Achilles tendon, and has obvious anti-adhesion effect.
Animals
;
Achilles Tendon/injuries*
;
Male
;
Rats
;
Rats, Sprague-Dawley
;
Collagen Type I/metabolism*
;
Collagen Type III/metabolism*
;
Tendon Injuries/therapy*
;
Wound Healing
;
Stress, Mechanical
;
Actins/metabolism*
;
Cells, Cultured
;
Tissue Adhesions/prevention & control*
;
Tumor Necrosis Factor-alpha/metabolism*
;
RNA, Messenger/genetics*
;
Disease Models, Animal
;
Collagen Type I, alpha 1 Chain/metabolism*
;
Biomechanical Phenomena
;
Basic Helix-Loop-Helix Transcription Factors
8.MiR-340 mediates the involvement of high mobility group box 1 in the pathogenesis of liver fibrosis.
Sha Ling LI ; Pan Pan YI ; Ruo Chan CHEN ; Ze Bing HUANG ; Xing Wang HU ; Xue Gong FAN
Chinese Journal of Hepatology 2023;31(1):77-83
Objective: To explore the pathogenic mechanism of the miR-340/high mobility group box 1 (HMGB1) axis in the formation of liver fibrosis. Methods: A rat liver fibrosis model was established by injecting CCl(4) intraperitoneally. miRNAs targeting and validating HMGB1 were selected with gene microarrays after screening the differentially expressed miRNAs in rats with normal and hepatic fibrosis. The effect of miRNA expressional changes on HMGB1 levels was detected by qPCR. Dual luciferase gene reporter assays (LUC) was used to verify the targeting relationship between miR-340 and HMGB1. The proliferative activity of the hepatic stellate cell line HSC-T6 was detected by thiazolyl blue tetrazolium bromide (MTT) assay after co-transfection of miRNA mimics and HMGB1 overexpression vector, and the expression of extracellular matrix (ECM) proteins type I collagen and α-smooth muscle actin (SMA) was detected by western blot. Statistical analysis was performed by analysis of variance and the LSD-t test. Results: Hematoxylin-eosin and Masson staining results showed that the rat model of liver fibrosis was successfully established. Gene microarray analysis and bioinformatics prediction had detected eight miRNAs possibly targeting HMGB1, and animal model validation had detected miR-340. qPCR detection results showed that miR-340 had inhibited the expression of HMGB1, and a luciferase complementation assay suggested that miR-340 had targeted HMGB1. Functional experiments results showed that HMGB1 overexpression had enhanced cell proliferation activity and the expression of type I collagen and α-SMA, while miR-340 mimics had not only inhibited cell proliferation activity and the expression of HMGB1, type I collagen, and α-SMA, but also partially reversed the promoting effect of HMGB1 on cell proliferation and ECM synthesis. Conclusion: miR-340 targets HMGB1 to inhibit the proliferation and ECM deposition in hepatic stellate cells and plays a protective role during the process of liver fibrosis.
Animals
;
Rats
;
Cell Proliferation
;
Collagen Type I/metabolism*
;
Fibrosis
;
Hepatic Stellate Cells
;
HMGB1 Protein/genetics*
;
Liver Cirrhosis/pathology*
;
MicroRNAs/metabolism*
9.Cryptic COL1A1-PDGFB fusion in dermatofibrosarcoma protuberans: a clinicopathological and genetic analysis.
Min CHEN ; Yu Mei CHEN ; Yang LU ; Xin HE ; Heng PENG ; Hong Ying ZHANG
Chinese Journal of Pathology 2023;52(1):13-18
Objective: To investigate the clinicopathological and cytogenetic features of cryptic COL1A1-PDGFB fusion dermatofibrosarcoma protuberans (CC-DFSP). Methods: Three cases of CC-DFSP diagnosed in West China Hospital, Sichuan University, Chengdu, China from January 2021 to September 2021 were studied. Immunohistochemistry for CD34 and other markers, fluorescence in situ hybridization (FISH) for PDGFB, COL1A1-PDGFB and COL1A1, next-generation sequencing (NGS), reverse-transcriptase polymerase chain reaction (RT-PCR) and Sanger sequencing were performed. Results: There were three cases of CC-DFSP, including two females and one male. The patients were 29, 44 and 32 years old, respectively. The sites were abdominal wall, caruncle and scapula. Microscopically, they were poorly circumscribed. The spindle cells of the tumors infiltrated into the whole dermis or subcutaneous tissues, typically arranging in a storiform pattern. Immunohistochemically, the neoplastic cells exhibited diffuse CD34 expression, but were negative for S-100, SMA, and Myogenin. Loss of H3K27me3 was not observed in the tumor cells. The Ki-67 index was 10%-15%. The 3 cases were all negative for PDGFB rearrangement and COL1A1-PDGFB fusion, whereas showing unbalanced rearrangement for COL1A1. Case 1 showed a COL1A1 (exon 31)-PDGFB (exon 2) fusion using NGS, which was further validated through RT-PCR and Sanger sequencing. All patients underwent extended surgical resection. Except for case 3 with recurrence 2 years after surgical resection, the other 2 cases showed no recurrence or metastasis during the follow-up. Conclusions: FISH has shown its validity for detecting PDGFB rearrangement and COL1A1-PDGFB fusion and widely applied in clinical detection. However, for cases with negative routine FISH screening that were highly suspicious for DFSPs, supplementary NGS or at least COL1A1 break-apart FISH screening could be helpful to identify cryptic COL1A1-PDGFB fusions or other variant fusions.
Female
;
Humans
;
Male
;
Collagen Type I, alpha 1 Chain
;
Dermatofibrosarcoma/pathology*
;
In Situ Hybridization, Fluorescence
;
Oncogene Proteins, Fusion/genetics*
;
Proto-Oncogene Proteins c-sis/genetics*
;
Skin Neoplasms/pathology*
;
Adult
10.Research on Runx2 gene induced differentiation of human amniotic mesenchymal stem cells into ligament fibroblasts <i>in vitroi> and promotion of tendon-bone healing in rabbits.
Tao XIE ; Hehe ZHONG ; Ying JIN ; Xiuqi LIU ; Fang CHEN ; Kuan XIANG ; Shuhong WU
Chinese Journal of Reparative and Reconstructive Surgery 2023;37(12):1523-1532
OBJECTIVE:
To investigate whether the Runx2 gene can induce the differentiation of human amniotic mesenchymal stem cells (hAMSCs) to ligament fibroblasts <i>in vitroi> and promote the tendon-bone healing in rabbits.
METHODS:
hAMSCs were isolated from the placentas voluntarily donated from healthy parturients and passaged, and then identified by flow cytometric identification. Adenoviral vectors carrying Runx2 gene (Ad-Runx2) and empty vector adenovirus (Ad-NC) were constructed and viral titer assay; then, the 3rd generation hAMSCs were transfected with Ad-Runx2 (Ad-Runx2 group) or Ad-NC (Ad-NC group). The real-time fluorescence quantitative PCR and Western blot were used to detect Runx2 gene and protein expression to verify the effectiveness of Ad-Runx2 transfection of hAMSCs; and at 3 and 7 days after transfection, real-time fluorescence quantitative PCR was further used to detect the expressions of ligament fibroblast-related genes [vascular endothelial growth factor (VEGF), collagen type Ⅰ, Fibronectin, and Tenascin-C]. The hAMSCs were used as a blank control group. The hAMSCs, hAMSCs transfected with Ad-NC, and hAMSCs were mixed with Matrigel according to the ratio of 1 : 1 and 1 : 2 to construct the cell-scaffold compound. Cell proliferation was detected by cell counting kit 8 (CCK-8) assay, and the corresponding cell-scaffold compound with better proliferation were taken for subsequent animal experiments. Twelve New Zealand white rabbits were randomly divided into 4 groups of sham operation group (Sham group), anterior cruciate ligament reconstruction group (ACLR group), anterior cruciate ligament reconstruction+hAMSCs transfected with Ad-NC-scaffold compound group (Ad-NC group), and anterior cruciate ligament reconstruction+hAMSCs transfected with Ad-Runx2-scaffold compound group (Ad-Runx2 group), with 3 rabbits in each group. After preparing the ACL reconstruction model, the Ad-NC group and the Ad-Runx2 group injected the optimal hAMSCs-Matrigel compunds into the bone channel correspondingly. The samples were taken for gross, histological (HE staining and sirius red staining), and immunofluorescence staining observation at 1 month after operation to evaluate the inflammatory cell infiltration as well as collagen and Tenascin-C content in the ligament tissues.
RESULTS:
Flow cytometric identification of the isolated cells conformed to the phenotypic characteristics of MSCs. The Runx2 gene was successfully transfected into hAMSCs. Compared with the Ad-NC group, the relative expressions of VEGF and collagen type Ⅰ genes in the Ad-Runx2 group significantly increased at 3 and 7 days after transfection ( <i>Pi><0.05), Fibronectin significantly increased at 3 days ( <i>Pi><0.05), and Tenascin-C significantly increased at 3 days and decreased at 7 days ( <i>Pi><0.05). CCK-8 detection showed that there was no significant difference ( <i>Pi>>0.05) in the cell proliferation between groups and between different time points after mixed culture of two ratios. So the cell-scaffold compound constructed in the ratio of 1∶1 was selected for subsequent experiments. Animal experiments showed that at 1 month after operation, the continuity of the grafted tendon was complete in all groups; HE staining showed that the tissue repair in the Ad-Runx2 group was better and there were fewer inflammatory cells when compared with the ACLR group and the Ad-NC group; sirius red staining and immunofluorescence staining showed that the Ad-Runx2 group had more collagen typeⅠ and Ⅲ fibers, tending to form a normal ACL structure. However, the fluorescence intensity of Tenascin-C protein was weakening when compared to the ACLR and Ad-NC groups.
CONCLUSION
Runx2 gene transfection of hAMSCs induces directed differentiation to ligament fibroblasts and promotes tendon-bone healing in reconstructed anterior cruciate ligament in rabbits.
Pregnancy
;
Female
;
Humans
;
Rabbits
;
Animals
;
Vascular Endothelial Growth Factor A/metabolism*
;
Fibronectins/metabolism*
;
Collagen Type I/genetics*
;
Tenascin/metabolism*
;
Collagen/metabolism*
;
Anterior Cruciate Ligament/surgery*
;
Mesenchymal Stem Cells
;
Tendons/metabolism*
;
Fibroblasts/metabolism*

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