RESUMEN
The existence and anatomy of the anterolateral ligament (ALL) of the knee are a somewhat controversial topic in orthopaedic surgery. The fixation of the avulsion fracture of the ALL (Segond fracture), associated with periarticular knee fractures, is rarely given much consideration while the major fracture fragments are reconstructed. This study aims to confirm the existence of ALL and evaluate the clinical outcomes of surgical management for avulsion fractures, involving its insertion, when associated with periarticular knee fractures. Twenty-three patients (16 males and 7 females) with avulsion fractures of the ALL associated with periarticular knee fractures were fixed with a spider plate, cannulated screw, or suture anchor. Eight patients were diagnosed with distal femoral fracture, 10 with tibial plateau fracture, and 5 with tibial eminence avulsion fracture. All patients underwent X-rays at follow-up. Clinical and functional outcomes were assessed with the pivot-shift test, objective and subjective International Knee Documentation Committee (IKDC) score, Lysholm score, and Tegner activity scale. The ALL was found and identified as a distinct ligamentous structure in all patients. Prior to Segond repair, patients had significantly more instability, as determined by pivot-shift test, than seen postoperatively (p < 0.0001). At final follow-up, the mean subjective IKDC score was 83.2 ± 10.3. Fourteen patients were graded A, 6 were graded B, and 3 was graded C on the IKDC objective score. The mean Lysholm score was 85.4 ± 12.2. The mean Tegner score was 7.5 ± 1.2. This study confirmed that the ALL is a distinct structure in the anterolateral portion of the knee. The fixation of the avulsion fracture of the ALL associated with periarticular knee fractures can be an effective procedure without specific complications. Long-term and comparative follow-up studies are necessary to confirm the effects.
Asunto(s)
Fracturas por Avulsión , Fracturas de Rodilla , Fracturas de la Tibia , Masculino , Femenino , Humanos , Resultado del Tratamiento , Artroscopía/métodos , Articulación de la Rodilla/cirugía , Ligamento Cruzado Anterior/cirugía , Fracturas de la Tibia/cirugía , Fijación Interna de Fracturas , Técnicas de Sutura , Estudios RetrospectivosRESUMEN
BACKGROUND: Aging-associated osteoporosis is frequently seen in the elderly in clinic, but efficient managements are limited because of unclear nosogenesis. The current study aims to investigate the role of melatonin on senescent bone marrow stromal cells (BMSCs) and the underlying regulating mechanism. METHODS: Melatonin levels were tested by ELISA. Gene expression profiles were performed by RNA-sequencing, enrichment of H3K36me2 on gene promoters was analyzed by Chromatin Immunoprecipitation Sequencing (ChIP-seq), and chromatin accessibility was determined by Assay for Transposase-Accessible Chromatin with high-throughput sequencing (ATAC-seq). Osteogenesis of BMSCs in vitro was measured by Alizarin Red and Alkaline Phosphatase staining, and in vivo effects of melatonin was assessed by histological staining and micro computed tomography (micro-CT) scan. Correlation of NSD2 expression and severity of senile osteoporosis patients were analyzed by Pearson correlation. RESULTS: Melatonin levels were decreased during aging in human bone marrow, accompanied by downregulation of the histone methyltransferase nuclear receptor binding SET domain protein 2 (NSD2) expression in the senescent BMSCs. Melatonin stimulated the expression of NSD2 through MT1/2-mediated signaling pathways, resulting in the rebalancing of H3K36me2 and H3K27me3 modifications to increase chromatin accessibility of the osteogenic genes, runt-related transcription factor 2 (RUNX2) and bone gamma-carboxyglutamate protein (BGLAP). Melatonin promoted osteogenesis of BMSCs in vitro, and alleviates osteoporosis progression in the aging mice. In clinic, severity of senile osteoporosis (SOP) was negatively correlated with melatonin level in bone marrow, as well as NSD2 expression in BMSCs. Similarly, melatonin remarkably enhanced osteogenic differentiation of BMSCs derived from SOP patients in vitro. CONCLUSIONS: Collectively, our study dissects previously unreported mechanistic insights into the epigenetic regulating machinery of melatonin in meliorating osteogenic differentiation of senescent BMSC, and provides evidence for application of melatonin in preventing aging-associated bone loss.
Asunto(s)
Ensamble y Desensamble de Cromatina/efectos de los fármacos , N-Metiltransferasa de Histona-Lisina/farmacología , Melatonina/metabolismo , Células Madre Mesenquimatosas/efectos de los fármacos , Osteoblastos/efectos de los fármacos , Proteínas Represoras/farmacología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Diferenciación Celular/efectos de los fármacos , Ensamble y Desensamble de Cromatina/genética , Ensamble y Desensamble de Cromatina/fisiología , Modelos Animales de Enfermedad , Femenino , N-Metiltransferasa de Histona-Lisina/metabolismo , Humanos , Masculino , Melatonina/uso terapéutico , Células Madre Mesenquimatosas/metabolismo , Ratones Endogámicos C57BL/metabolismo , Persona de Mediana Edad , Osteoblastos/fisiología , Proteínas Represoras/metabolismoRESUMEN
Platelet-rich plasma (PRP) and stem cell (SC) injections have become increasingly common in the treatment of knee arthritis. This systematic review was performed to answer the following questions: (1) What effects does intraarticular PRP injection have in the setting of knee arthritis? (2) What effects does intra-articular SC injection have in the setting of knee arthritis? (3) What adverse events have been reported in the literature from PRP injections for knee arthritis? (4) What adverse events have been reported in the literature from SC injections for knee arthritis? [Orthopedics. 2021;44(6):376-383.].
Asunto(s)
Osteoartritis de la Rodilla , Plasma Rico en Plaquetas , Humanos , Ácido Hialurónico/uso terapéutico , Inyecciones Intraarticulares , Osteoartritis de la Rodilla/tratamiento farmacológico , Células Madre , Resultado del TratamientoRESUMEN
Porcine deltacoronavirus (PDCoV) is a novel porcine enteric coronavirus that causes diarrhea, vomiting and dehydration in piglets. This newly virus has spread rapidly and has caused serious economic losses for pig industry since the outbreak in USA in 2014. In this study, 430 faecal and intestinal samples (143 faecal samples and 287 intestinal samples) were collected from individual pigs with diarrhea and 211 serum samples were also collected from the sows with mild diarrhea in 17 regions in Henan province, China from April 2015 to March 2018. The RT-PCR detection indicated that the infection of PDCoV was high up to 23.49% (101/430), and co-infection with PEDV were common (60.40%, 61/101) in Henan pigs. The prevalence of PDCoV in suckling piglets was the highest (36.43%, 94/258). We also found that PDCoV could be detected in sows faeces and sera while the sows showed mild, self-limited diarrhea in clinic. The complete genomes of 4 PDCoV Henan strains (CH-01, HNZK-02, HNZK-04, HNZK-06) were sequenced and analyzed. Phylogenetic analysis based on the complete genome, spike and nucleocapsid gene sequences revealed that the PDCoV Henan strains were closely related to other PDCoV reference strains that located in the Chinese clade. Furthermore, the phylogenetic analysis showed PDCoV CH-01 strain was closely related to CHN-HB-2014 strain and HKU15-44 strain, while the other PDCoV Henan strains were more related to PDCoV CHJXNI2 and CH-SXD1-2015 strains, indicating that the ancestor of these sequenced strains may different. These results would support the understanding of the prevalence and evolution characteristics of PDCoV in China.
Asunto(s)
Infecciones por Coronavirus/veterinaria , Coronavirus/fisiología , Diarrea/veterinaria , Genoma Viral , Enfermedades de los Porcinos/epidemiología , Animales , China , Coronavirus/clasificación , Coronavirus/genética , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/virología , Diarrea/epidemiología , Diarrea/virología , Heces/virología , Contenido Digestivo/virología , Filogenia , Prevalencia , Análisis de Secuencia de ARN/veterinaria , Sus scrofa , Porcinos , Enfermedades de los Porcinos/virologíaRESUMEN
OBJECTIVE: The aim of this meta-analysis of randomized controlled trials (RCT) and retrospective cohort studies (CS) regarding the use of volar locking plate (VLP) and external fixation (EF) in distal radius fractures was to determine whether there was any evidence that one treatment was superior to the other. METHODS: The meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Electrical databases (PubMed, EMBASE and the Cochrane library) were retrieved to find RCTs and CSs met the eligibility criteria. Two reviewers screened the studies, extracted the data and evaluated the methodological quality, and performed data analysis with RevMan 5.1. The publication bias was test by Stata 14.0. The Begg's and Egger's test were performed by Stata 14.0. The quality of evidence was graded according to the criteria of GRADE. We ultimately included ten RCTs and eleven CSs. RESULTS: A total of 1590 subjects were reported. Publication bias was detected by funnel plot in RCTs. VLP could provide better results such as DASH scores (RCT: MD = -6.12, 95%CI = -12.07-0.17; CS: MD = -6.43, 95%CI = -12.53-0.3), ulnar variance (RCT: MD = -0.81, 95%CI = -1.25-0.37) and infection rate (RCT: RR = 0.25, 95%CI = 0.10-0.65; CS: RR = 0.15, 95%CI = 0.06-0.40). There were no significant differences for G-W scores, VAS and grip strength between the VLP group and EF group. There was significantly greater loss of volar tilt (P = 0.01) and radial inclination (P = 0.02) in patients receiving EF, basing on the CSs. CONCLUSIONS: VLP could provide better results, such as DASH scores, ulnar variance, volar tilt, radial inclination and infection rate. The use of VLP appear to be associated with better results of ROM (flexion, pronation, supination and radial deviation), radiographic parameters (volar tilt and radial inclination) and lower total complication rate and CRPS rate in CSs. LEVEL OF EVIDENCE: Level 1, Therapeutic study.
Asunto(s)
Placas Óseas , Técnica de Ilizarov/instrumentación , Fracturas del Radio/cirugía , Fijadores Externos , Humanos , Resultado del TratamientoRESUMEN
Osteoarthritis (OA) is the leading degenerative joint disease and featured by articular cartilage destruction, where chondrocyte apoptosis plays a critical role. Semaphorin-3A (Sema3A) has been implicated in OA chondrocyte physiology. In this study we aimed to uncover how Sema3A signaling is regulated in chondrocytes and investigate its role in OA chondrocyte survival. Here, we report that Sema3A and its receptor neuropilin-1 (Nrp1) are synchronously upregulated in cartilage chondrocytes of knee OA patients. Their expressions in chondrocytes could be induced by the stimulation of proinflammatory cytokines IL-1ß and TNF-α and subsequent transcriptional activation orchestrated by C/EBPß. The resulting excessive Sema3A signaling promotes chondrocyte apoptosis through impairing PI3K/Akt prosurvival signaling. These findings indicate a regulatory mechanism and a proapoptotic function of aberrant Sema3A signaling in OA chondrocytes, and suggest that targeting Sema3A signaling might interfere OA pathogenesis.
Asunto(s)
Apoptosis , Condrocitos/metabolismo , Osteoartritis de la Rodilla/metabolismo , Semaforina-3A/metabolismo , Transducción de Señal , Anciano , Animales , Condrocitos/patología , Femenino , Humanos , Masculino , Ratones , Persona de Mediana Edad , Osteoartritis de la Rodilla/patologíaRESUMEN
GRX1 (glutaredoxin1), a sulfhydryl disulfide oxidoreductase, is involved in many cellular processes, including anti-oxidation, anti-apoptosis, and regulation of cell differentiation. However, the role of GRX1 in the oxidative stress and apoptosis of osteoarthritis chondrocytes remains unclear, prompting the current study. Protein and mRNA expressions were measured by Western blot and RT-qPCR. Oxidative stress was detected by the measurement of MDA and SOD contents. Cells apoptosis were detected by Annexin V-FITC/PI and caspase-3 activity assays. We found that the mRNA and protein expressions of GRX1 were significantly down-regulated in osteoarthritis tissues and cells. GRX1 overexpression increased the mRNA and protein expression of CREB and HO-1. Meanwhile, GRX1 overexpression inhibited oxidative stress and apoptosis in osteoarthritis chondrocytes. Furthermore, we found that GRX1 overexpression regulated HO-1 by increasing CREB, and that HO-1 regulated oxidative stress and apoptosis in osteoarthritis chondrocytes. Thus, GRX1 overexpression constrains oxidative stress and apoptosis in osteoarthritis chondrocytes by regulating CREB/HO-1, providing a novel insight into the molecular mechanism and potential treatment of osteoarthritis.
Asunto(s)
Apoptosis/fisiología , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Glutarredoxinas/metabolismo , Hemo-Oxigenasa 1/metabolismo , Osteoartritis/patología , Estrés Oxidativo/fisiología , Anciano , Células Cultivadas , Condrocitos/patología , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/genética , Femenino , Glutarredoxinas/genética , Hemo-Oxigenasa 1/genética , Humanos , Masculino , Malondialdehído/metabolismo , Persona de Mediana Edad , Oxidación-Reducción , ARN Mensajero/biosíntesis , Superóxido Dismutasa-1/metabolismoRESUMEN
Graft remodeling following anterior cruciate ligament (ACL) reconstruction requires a long period of recovery before it is capable of withstanding physiological loads. Graft revascularization is extremely important in the remodeling process. In ACL reconstruction, the local administration of vascular endothelial growth factor (VEGF) significantly increased revascularization of the graft, but did not significantly affect the mechanical properties of the graft after implantation (Ju et al., 2006; Yoshikawa, et al., 2006). Our previous studies showed that transforming growth factor-ß1 (TGFß1) could promote improvements in mechanical strength in Achilles tendon regeneration, by regulating collagen type I and type III synthesis, cross-link formation, and matrix-remodeling (Hou et al., 2009). The current study aims to investigate whether the co-expression of TGFß1/VEGF(165) could beneficially affect the remodeling of ACL grafts. Bone marrow-derived mesenchymal stem cells (BMSCs), transfected with an adenoviral vector encoding TGFß1, VEGF(165) or TGFß1/VEGF(165), were surgically implanted into experimental ACL grafts, with non-transfected cells as a control. HE and toluidine blue staining, vascular number, and biomechanical features were analyzed at 3, 6, 12, and 24 weeks after surgery. The results suggest that TGFß1 expression, in the TGFß1/VEGF(165)-transfected BMSCs, could accelerate the remodeling of the reconstructed ligament. The cross-talk between TGFß1 and VEGF(165) has positive consequences, as TGFß1/VEGF(165)-transfected BMSCs significantly promoted angiogenesis of the reconstructed ligament at 3, 6, 12 weeks, with the best mechanical properties being achieved at 24 weeks. Furthermore, co-expression of these genes is more powerful and efficient than single gene therapy.
Asunto(s)
Ligamento Cruzado Anterior/fisiología , Terapia Genética/métodos , Trasplante de Células Madre Mesenquimatosas/métodos , Células Madre Mesenquimatosas/metabolismo , Regeneración , Factor de Crecimiento Transformador beta/genética , Factor A de Crecimiento Endotelial Vascular/genética , Tendón Calcáneo/fisiología , Tendón Calcáneo/trasplante , Animales , Ligamento Cruzado Anterior/cirugía , Lesiones del Ligamento Cruzado Anterior , Expresión Génica , Fenómenos Mecánicos , Molécula-1 de Adhesión Celular Endotelial de Plaqueta/metabolismo , Conejos , Transducción GenéticaRESUMEN
OBJECTIVE: To review recent advance in the research and application of computer aided forming techniques for constructing bone tissue engineering scaffolds. METHODS: The literature concerning computer aided forming techniques for constructing bone tissue engineering scaffolds in recent years was reviewed extensively and summarized. RESULTS: Several studies over last decade have focused on computer aided forming techniques for bone scaffold construction using various scaffold materials, which is based on computer aided design (CAD) and bone scaffold rapid prototyping (RP). CAD include medical CAD, STL, and reverse design. Reverse design can fully simulate normal bone tissue and could be very useful for the CAD. RP techniques include fused deposition modeling, three dimensional printing, selected laser sintering, three dimensional bioplotting, and low-temperature deposition manufacturing. These techniques provide a new way to construct bone tissue engineering scaffolds with complex internal structures. CONCLUSION: With rapid development of molding and forming techniques, computer aided forming techniques are expected to provide ideal bone tissue engineering scaffolds.
Asunto(s)
Diseño Asistido por Computadora , Ingeniería de Tejidos/métodos , Materiales Manufacturados , Andamios del TejidoRESUMEN
We compared bone marrow stem cells (BMSCs) and adipose-derived stem cells (ADSCs) of adult rabbits under identical conditions in terms of their culture characteristics, proliferation capacity, osteogenic differentiation potentials induced by adenovirus-containing bone morphogenetic protein 4 (Ad-BMP4) in vitro, and capacity to repair calvarial defects in the rabbit model by autologous transplantation ex vivo. According to the results of growth curve, cell cycle, and telomerase activity analysis, ADSCs possess a higher proliferation potential. Both of the Ad-BMP4 transduced MSCs expressed BMP4 mRNA and protein and underwent osteogenic differentiation. Up-regulated mRNA expression of all osteogenic genes was observed in differentiated BMSCs and ADSCs, but with different patterns confirmed by real-time RT-PCR. Deposition of calcified extracellular matrix was significantly greater in differentiated ADSCs compared with differentiated BMSCs. X-ray and histological examination indicated significant bone regeneration in the calvarial defects transplanted with Ad-BMP4 transduced autologous MSCs compared to the control groups. There was no significant difference in new bone formation in Ad-BMP4 transduced MSCs based on quantitative digital analysis of histological sections. The use of ADSCs often resulted in the growth of fat tissue structures in the control groups, and the fat tissue structures were not seen with BMSC cells. Our data demonstrate that BMP4 can be potently osteoinductive in vivo, resulting in bone repair. ADSCs may be an attractive alternative to BMSCs for bone tissue engineering under appropriate stimuli. But the easy adipogenic differentiation needs to be considered when choosing adipose tissue for specific clinical application.
Asunto(s)
Tejido Adiposo/citología , Células de la Médula Ósea/citología , Proteína Morfogenética Ósea 4/genética , Osteogénesis/fisiología , Células Madre/citología , Tejido Adiposo/metabolismo , Animales , Células de la Médula Ósea/metabolismo , Proteína Morfogenética Ósea 4/metabolismo , Regeneración Ósea , Proliferación Celular , Células Cultivadas , Técnica del Anticuerpo Fluorescente , Masculino , ARN Mensajero/metabolismo , Conejos , Cráneo/anatomía & histología , Cráneo/fisiología , Cráneo/cirugía , Células Madre/metabolismo , Transducción Genética , Trasplante AutólogoRESUMEN
Collagen content and cross-linking are believed to be major determinants of tendon structural integrity and function. The current study aimed to investigate the effects of transforming growth factor (TGF)-beta1 on the collagen content and cross-linking of Achilles tendons, and on the histological and biomechanical changes occurring during Achilles tendon healing in rabbits. Bone marrow-derived mesenchymal stem cells (BMSCs) transfected with the TGF-beta1 gene were surgically implanted into experimentally injured Achilles tendons. Collagen proteins were identified by immunohistochemical staining and fiber bundle accumulation was revealed by Sirius red staining. Achilles tendons treated with TGF-beta1-transfected BMSCs showed higher concentrations of collagen I protein, more rapid matrix remodeling, and larger fiber bundles. Thus TGF-beta1 can promote mechanical strength in healing Achilles tendons by regulating collagen synthesis, cross-link formation, and matrix remodeling.
Asunto(s)
Tendón Calcáneo/lesiones , Colágeno/biosíntesis , Terapia Genética , Traumatismos de los Tendones/terapia , Factor de Crecimiento Transformador beta1/genética , Cicatrización de Heridas , Tendón Calcáneo/metabolismo , Tendón Calcáneo/fisiología , Animales , Humanos , Inmunohistoquímica , Masculino , Conejos , Estrés Mecánico , Traumatismos de los Tendones/metabolismoRESUMEN
Repaired Achilles tendons typically take weeks before they are strong enough to handle physiological loads. Gene therapy is a promising treatment for Achilles tendon defects. The aim of the present study was to evaluate the histological/biomechanical effects of Transforming growth factor-beta1 (TGF-beta1) and vascular endothelial growth factor 165 (VEGF(165)) gene transfer on Achilles tendon healing in rabbits. Bone Marrow-Derived Mesenchymal Stem Cells (BMSCs) were transduced with adenovirus carrying human TGF-beta1 cDNA (Ad-TGF-beta1), human VEGF(165) cDNA (Ad-VEGF(165)), or both (PIRES-TGF-beta1/VEGF(165)) Viruses, no cDNA (Ad-GFP), and the BMSCs without gene transfer and the intact tendon were used as control. BMSCs were surgically implanted into the experimentally injured Achilles tendons. TGF-beta1 distribution, cellularity, nuclear aspect ratio, nuclear orientation angle, vascular number, collagen synthesis, and biomechanical features were measured at 1, 2, 4, and 8 weeks after surgery. The TGF-beta1 and TGF beta 1/VEGF(165) co-expression groups exhibited improved parameters compared with other groups, while the VEGF(165) expression group had a negative impact. In the co-expression group, the angiogenesis effects of VEGF(165) were diminished by TGF-beta1, while the collagen synthesis effects of TGF-beta1 were unaltered by VEGF(165). Thus treatment with TGF-beta1 cDNA-transduced BMSCs grafts is a promising therapy for acceleration and improvement of tendon healing, leading to quicker recovery and improved biomechanical properties of Achilles tendons.
Asunto(s)
Tendón Calcáneo/fisiología , Técnicas de Transferencia de Gen , Regeneración/fisiología , Factor de Crecimiento Transformador beta1/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo , Tendón Calcáneo/anatomía & histología , Animales , Fenómenos Biomecánicos , Células de la Médula Ósea/citología , Células de la Médula Ósea/fisiología , Terapia Genética , Vectores Genéticos/genética , Vectores Genéticos/metabolismo , Humanos , Masculino , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/fisiología , Conejos , Factor de Crecimiento Transformador beta1/genética , Factor A de Crecimiento Endotelial Vascular/genéticaRESUMEN
BACKGROUND: Remodeling of the anterior cruciate ligament (ACL) graft usually takes longer than expected. Gene therapy offers a radical different approach to remodeling of the graft. In this study, the internal ribosome entry site (IRES) sequence was used to construct a new recombinant adenovirus which permits co-expression of transforming growth factor-beta1 (TGFbeta1) and vascular endothelial growth factor 165 (VEGF165) genes (named Ad-VEGF165-IRES-TGFbeta1). We investigated the effects of the new adenovirus on the migration of and matrix synthesis by ACL fibroblasts. METHODS: Adenoviral vector containing TGFbeta1 and VEGF165 genes was constructed. ACL fibroblasts were obtained from New Zealand white rabbits. After ACL fibroblasts were exposed to Ad-VEGF165-IRES-TGFbeta1, the expression of VEGF165 and TGFbeta1 proteins were assessed by enzyme-linked immunosorbent assay (ELISA) and Western blotting analysis. Bioassay of VEGF165 and TGFbeta1 proteins were assessed by Western blotting analysis. Proliferation and migration of ACL fibroblasts were assessed by in vitro wound closure assay. Gene expression of collagen type I, collagen type III, and fibronectin mRNA among matrix markers were assessed by real-time PCR. RESULTS: The results showed the successful construction of a recombinant co-expression adenovirus vector containing TGFbeta1 and VEGF165 genes. Co-expression of TGFbeta1 and VEGF165 can induce relatively rapid and continuous proliferation of ACL fibroblasts and high gene expression of collagen type I, collagen type III, and fibronectin mRNA among matrix markers. CONCLUSION: Co-expression of TGFbeta1 and VEGF165 genes has more powerful and efficient effects on the migration of and matrix synthesis by ACL fibroblasts.
Asunto(s)
Ligamento Cruzado Anterior/metabolismo , Terapia Genética , Factor de Crecimiento Transformador beta1/genética , Factor A de Crecimiento Endotelial Vascular/genética , Adenoviridae/genética , Animales , Ligamento Cruzado Anterior/citología , Movimiento Celular , Células Cultivadas , Colágeno/genética , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Fibroblastos/fisiología , Fibronectinas/genética , Vectores Genéticos , Humanos , Conejos , Cicatrización de HeridasRESUMEN
OBJECTIVE: To observe redifferentiation of dedifferentiated chondrocytes after transplantation into the joint, and to evaluate the ability of dedifferentiated chondrocytes transduced with adenovirus containing bone morphogenetic protein 4 (BMP-4) to redifferentiate in vitro and in vivo in a rabbit model of articular cartilage defects. METHODS: Monolayer and pellet culture systems were used to evaluate the redifferentiation of dedifferentiated chondrocytes transduced with BMP-4. A rabbit model of partial-thickness articular cartilage defects was used to evaluate cartilage repair macroscopically and histologically, 6 and 12 weeks after transplantation with first-passage, fifth-passage, or transduced fifth-passage chondrocytes. Histologic grading of the repaired tissue was performed. Expression of BMP-4 and the ability of transplanted cells to recover a chondrocytic phenotype were also assessed. RESULTS: BMP-4--expressing dedifferentiated chondrocytes recovered a chondrocytic phenotype in vitro. After transplantation into the joint, some of the dedifferentiated chondrocytes in the defect sites could undergo redifferentiation and formed matrix that displayed positive toluidine blue staining for glycosaminoglycans. Histologic scores of the regenerative tissue revealed significantly better cartilage repair in rabbits transplanted with BMP-4--expressing cells than in the other treatment groups. Staining with toluidine blue revealed expression of BMP-4 in the cells and in the matrix surrounding the cells. CONCLUSION: Some dedifferentiated chondrocytes can redifferentiate after transplantation into the load-bearing joint. BMP-4 can be used to induce redifferentiation of dedifferentiated chondrocytes in vitro and in vivo, which could help enhance articular cartilage repair.
Asunto(s)
Proteínas Morfogenéticas Óseas/metabolismo , Cartílago Articular , Diferenciación Celular/fisiología , Condrocitos/fisiología , Condrocitos/trasplante , Animales , Proteína Morfogenética Ósea 4 , Proteínas Morfogenéticas Óseas/genética , Cartílago Articular/fisiología , Cartílago Articular/trasplante , Células Cultivadas , Condrogénesis/fisiología , Modelos Animales de Enfermedad , Articulación de la Rodilla/fisiología , Masculino , Conejos , Transducción Genética , Soporte de Peso/fisiologíaRESUMEN
The heterotopic ossification of muscles, tendons, and ligaments is a common problem faced by orthopaedic surgeons. Runx2/Cbfa1 plays an essential role during the osteoblast differentiation and is considered as a molecular switch in osteoblast biology. RNA interference technology is a powerful tool for silencing endogenous or exogenous genes in mammalian cells. In this study, we investigated the effect of Runx2/Cbfa1-specific siRNA on osteoblast differentiation and mineralization in osteoblastic cells, and then constructed adenovirus containing siRNA against Runx2/Cbfa1 (Ad-Runx2-siRNA) to inhibit the formation of heterotopic ossification induced by BMP4, demineralized bone matrix, and trauma in animal model. Our results showed that the Runx2/Cbfa1-specific siRNA could inhibit the expression of Runx2/Cbfa1 at the level of mRNA and protein. Analysis of the expression of osteoblast maturation genes including type I collagen, osteopontin, bone sialoprotein, and osteocalcin, alkaline phosphatase activity, and matrix mineralization (von kossa) revealed that osteoblast differentiation was inhibited in cultured primary mouse osteoblasts transduced with Ad-Runx2-siRNA. Furthermore, adenovirus-mediated transfer of siRNA against Runx2/Cbfa1 could inhibit the formation of heterotopic ossification induced by BMP4, demineralized bone matrix, and trauma in animal model. It is likely that the inhibition of Runx2/Cbfa1 by RNAi could be developed as a powerful approach to prevent or treat heterotopic ossification.
Asunto(s)
Adenoviridae/metabolismo , Subunidad alfa 1 del Factor de Unión al Sitio Principal/genética , Regulación del Desarrollo de la Expresión Génica , Terapia Genética/métodos , ARN Interferente Pequeño/metabolismo , Animales , Cartilla de ADN/química , Modelos Animales de Enfermedad , Vectores Genéticos , Ratones , Osificación Heterotópica/prevención & control , Osteoblastos/metabolismo , Interferencia de ARNRESUMEN
OBJECTIVE: To explore the neuroprotective effect of FK506 on acute spinal cord injury in dogs. METHODS: Acute spinal cord injury model was made with the Allen technique. Animals were randomly divided into 3 groups. Group A (n = 8) was the control group and received operation but no therapy, while group B and C (n = 8) received a single dose of FK506 (0.18 mg/kg and 0.3 mg/kg, respectively) administered with an arterial duct 2 h after spinal cord injury (SCI). Spine MRI, neurological function, histopathological examination of injured spinal cord and immunohistochemical examination of expression of NF(200) in neurons and GFAP in astrocytes were assessed at certain time after injury. RESULTS: Neurological function score of group C and B was better than that of group A (P < 0.05), with significance between group C and A, while no significance between group B and A statistically. The signal scope of spinal cord injury on MRI in group C was the smallest among all the groups, and the signal scope in group B was smaller than that in group A, which was directively associated with the neurological outcome. The expression of NF and GFAP was significantly higher in group C than in group A (P < 0.05), but without statistical significance between group B and A. CONCLUSION: Local administration of FK506 (0.3 mg/kg) possesses neuroprotective effect on acute spinal cord injury, which can improve neurological function recovery and attenuate secondary spinal cord injury. Local administration of FK506 possesses a dosage-effect relation.