RESUMEN
Intervertebral disc (IVD) herniation is a leading cause of disability and lower back pain, causing enormous socioeconomic burdens. The standard of care for disc herniation is nucleotomy, which alleviates pain but does not repair the annulus fibrosus (AF) defect nor recover the biomechanical function of the disc. Existing bioadhesives for AF repair are limited by insufficient adhesion and significant mechanical and geometrical mismatch with the AF tissue, resulting in the recurrence of protrusion or detachment of bioadhesives. Here, we report a composite hydrogel sealant constructed from a composite of a three-dimensional (3D)-printed thermoplastic polyurethane (TPU) mesh and tough hydrogel. We tailored the fiber angle and volume fraction of the TPU mesh design to match the angle-ply structure and mechanical properties of native AF. Also, we proposed and tested three types of geometrical design of the composite hydrogel sealant to match the defect shape and size. Our results show that the sealant could mimic native AF in terms of the elastic modulus, flexural modulus, and fracture toughness and form strong adhesion with the human AF tissue. The bovine IVD tests show the effectiveness of the composite hydrogel sealant for AF repair and biomechanics recovery and for preventing herniation with its heightened stiffness and superior adhesion. By harnessing the combined capabilities of 3D printing and bioadhesives, these composite hydrogel sealants demonstrate promising potential for diverse applications in tissue repair and regeneration.
Asunto(s)
Anillo Fibroso , Hidrogeles , Animales , Anillo Fibroso/efectos de los fármacos , Hidrogeles/química , Hidrogeles/farmacología , Bovinos , Humanos , Impresión Tridimensional , Poliuretanos/química , Poliuretanos/farmacología , Adhesivos Tisulares/farmacología , Adhesivos Tisulares/químicaRESUMEN
Avascular dense connective tissues (e.g., the annulus fibrosus (AF) rupture, the meniscus tear, and tendons and ligaments injury) repair remains a challenge due to the "biological barrier" that hinders traditional drug permeation and limits self-healing of the injured tissue. Here, accurate delivery of nitric oxide (NO) to penetrate the "AF biological barrier" is achieved thereby enabling programmable AF repair. NO-loaded BioMOFs are synthesized and mixed in a modified polyvinyl alcohol and PCL-composited electrospun fiber membrane with excellent reactive oxygen species-responsive capability (LN@PM). The results show that LN@PM could respond to the high oxidative stress environment at the injured tissue and realize continuous and substantial NO release. Based on low molecular weight and lipophilicity, NO could penetrate through the "biological barrier" for accurate AF drug delivery. Moreover, the dynamic characteristics of the LN@PM reaction can be matched with the pathological microenvironment to initiate programmable tissue repair including sequential remodeling microenvironment, reprogramming the immune environment, and finally promoting tissue regeneration. This tailored programmable treatment strategy that matches the pathological repair process significantly repairs AF, ultimately alleviating intervertebral disc degeneration. This study highlights a promising approach for avascular dense connective tissue treatment through intelligent NO release, effectively overcoming "AF biological barriers" and programmable treatment.
Asunto(s)
Óxido Nítrico , Óxido Nítrico/metabolismo , Animales , Anillo Fibroso/efectos de los fármacos , Sistemas de Liberación de Medicamentos/métodos , Tejido Conectivo , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno/metabolismo , Alcohol Polivinílico/química , Degeneración del Disco Intervertebral/metabolismo , Masculino , Ratas , Ratones , ConejosRESUMEN
Oxidative stress and apoptosis play important roles in the pathogenesis of various degenerative diseases. Previous studies have shown that naringin can exert therapeutic effects in multiple degenerative diseases by resisting oxidative stress and inhibiting apoptosis. Although naringin is effective in treating degenerative disc disease, the underlying mechanism remains unclear. This study is aimed at investigating the effects of naringin on oxidative stress, apoptosis, and intervertebral disc degeneration (IVDD) induced by cyclic stretch and the underlying mechanisms in vitro and in vivo. Abnormal cyclic stretch was applied to rat annulus fibrosus cells, which were then treated with naringin, to observe the effects of naringin on apoptosis, oxidative stress, mitochondrial function, and the nuclear factor- (NF-) κB signaling pathway. Subsequently, a rat model of IVDD induced by dynamic and static imbalance was established to evaluate the effects of naringin on the degree of degeneration (using imaging and histology), apoptosis, and oxidative stress in the serum and the intervertebral disc. Naringin inhibited the cyclic stretch-induced apoptosis of annulus fibrosus cells, reduced oxidative stress, improved mitochondrial function, enhanced the antioxidant capacity, and suppressed the activation of the NF-κB signaling pathway. Additionally, it reduced the degree of IVDD (evaluated using magnetic resonance imaging) and the level of oxidative stress and inhibited apoptosis and p-P65 expression in the intervertebral discs of rats. Thus, naringin can inhibit cyclic stretch-induced apoptosis and delay IVDD, and the underlying mechanism may be related to the inhibition of oxidative stress and activation of the NF-κB signaling pathway. Naringin may be an effective drug for treating degenerative disc disease.
Asunto(s)
Anillo Fibroso/citología , Anillo Fibroso/metabolismo , Antioxidantes/administración & dosificación , Apoptosis/efectos de los fármacos , Flavanonas/administración & dosificación , Degeneración del Disco Intervertebral/tratamiento farmacológico , Degeneración del Disco Intervertebral/metabolismo , FN-kappa B/metabolismo , Núcleo Pulposo/citología , Núcleo Pulposo/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal/efectos de los fármacos , Animales , Anillo Fibroso/efectos de los fármacos , Modelos Animales de Enfermedad , Masculino , Mitocondrias/metabolismo , Núcleo Pulposo/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Resultado del TratamientoRESUMEN
BACKGROUND: Intervertebral disc is responsible for absorbing and transmitting mechanical compression. Under physiological conditions, the peripheral annulus fibrosus (AF) cells are subjected to different magnitudes of transverse mechanical stretch depending on the swelling of the central nucleus pulposus tissue. However, the biological behavior of AF cells under mechanical stretch is not well studied. OBJECTIVE: This study was performed to study the effects of mechanical tension on AF cell senescence and the potential signaling transduction pathway. METHODS: Rat AF cells were made to experience different magnitudes of mechanical stretch (2% elongation and 20% elongation for 4 hours every day at 1 Hz) in a 10-day experiment period. The inhibitor RKI-1447 of the Rho-associated coiled-coil-containing protein kinases (ROCK) was added along with culture medium to investigate its role. Cell proliferation, cell cycle, telomerase activity, and expression of senescence markers (p16 and p53) were analyzed. RESULTS: We found that 20% elongation significantly decreased cell proliferation, promoted G0/G1 cell cycle arrest, decreased telomerase activity, and upregulated mRNA/protein expression of p16 and p53. Moreover, the inhibitor RKI-1447 partly resisted effects of 20% elongation on these parameters of cell senescence. CONCLUSION: High mechanical stretch obviously induces AF cell senescence through the RhoA/ROCK pathway. This study provides us a deeper understanding on the AF cell's behavior under mechanical stretch.
Asunto(s)
Anillo Fibroso/citología , Anillo Fibroso/fisiología , Proteínas de Unión al GTP rho/metabolismo , Quinasas Asociadas a rho/metabolismo , Animales , Anillo Fibroso/efectos de los fármacos , Proliferación Celular , Células Cultivadas , Senescencia Celular/fisiología , Puntos de Control de la Fase G1 del Ciclo Celular , Degeneración del Disco Intervertebral/etiología , Degeneración del Disco Intervertebral/patología , Degeneración del Disco Intervertebral/fisiopatología , Inhibidores de Proteínas Quinasas/farmacología , Ratas , Ratas Sprague-Dawley , Transducción de Señal/efectos de los fármacos , Estrés Mecánico , Telomerasa/metabolismo , Tiazoles/farmacología , Urea/análogos & derivados , Urea/farmacología , Quinasas Asociadas a rho/antagonistas & inhibidoresRESUMEN
During disc degeneration, the increase of inflammatory cytokines and decrease of disc cell density are two prominent features. Enhanced inflammatory reaction contributes to disc annulus fibrosus (AF) cell apoptosis. In this study, we investigated whether resveratrol can suppress AF cell apoptosis in an inflammatory environment. Rat disc AF cells were cultured in medium with or without tumor necrosis factor-α (TNF-α). Resveratrol was added along with the culture medium supplemented with TNF-α. Caspase-3 activity, cell apoptosis ratio, expression of apoptosis-associated molecules (Bcl-2, Bax, caspase-3, cleaved PARP, and cleaved caspase-3), reactive oxygen species (ROS) content, and the total superoxide dismutase (SOD) activity were measured. Our results showed that TNF-α significantly increased caspase-3 activity and AF cell apoptosis ratio and upregulated gene/protein expression of Bax, caspase-3, cleaved caspase-3, and cleaved PARP, whereas it downregulated the expression of Bcl-2. Moreover, TNF-α significantly increased ROS content but decreased the total SOD activity. Further analysis demonstrated that resveratrol partly attenuated the effects of TNF-α on AF cell apoptosis-associated parameters, decreased ROS content, and increased the total SOD activity in the AF cells treated with TNF-α. In conclusion, resveratrol attenuates inflammatory cytokine TNF-α-induced AF cell apoptosis through regulating oxidative stress reaction in vitro. This study sheds a new light on the protective role of resveratrol in alleviating disc degeneration.
Asunto(s)
Anillo Fibroso/patología , Apoptosis , Inflamación/patología , Estrés Oxidativo , Resveratrol/farmacología , Animales , Anillo Fibroso/efectos de los fármacos , Apoptosis/efectos de los fármacos , Apoptosis/genética , Biomarcadores/metabolismo , Caspasa 3/metabolismo , Caspasa 9/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Estrés Oxidativo/genética , Poli(ADP-Ribosa) Polimerasas/metabolismo , Ratas , Especies Reactivas de Oxígeno/metabolismo , Superóxido Dismutasa/metabolismoRESUMEN
Intervertebral disc degeneration is highly prevalent within the elderly population and is a leading cause of chronic back pain and disability. Due to the link between disc degeneration and senescence, we explored the ability of the Dasatinib and Quercetin drug combination (D + Q) to prevent an age-dependent progression of disc degeneration in mice. We treated C57BL/6 mice beginning at 6, 14, and 18 months of age, and analyzed them at 23 months of age. Interestingly, 6- and 14-month D + Q cohorts show lower incidences of degeneration, and the treatment results in a significant decrease in senescence markers p16INK4a, p19ARF, and SASP molecules IL-6 and MMP13. Treatment also preserves cell viability, phenotype, and matrix content. Although transcriptomic analysis shows disc compartment-specific effects of the treatment, cell death and cytokine response pathways are commonly modulated across tissue types. Results suggest that senolytics may provide an attractive strategy to mitigating age-dependent disc degeneration.
Asunto(s)
Envejecimiento/efectos de los fármacos , Dasatinib/uso terapéutico , Degeneración del Disco Intervertebral/tratamiento farmacológico , Quercetina/uso terapéutico , Agrecanos/metabolismo , Envejecimiento/metabolismo , Animales , Anillo Fibroso/efectos de los fármacos , Anillo Fibroso/metabolismo , Anillo Fibroso/patología , Supervivencia Celular/efectos de los fármacos , Senescencia Celular/efectos de los fármacos , Matriz Extracelular/efectos de los fármacos , Matriz Extracelular/metabolismo , Fibrosis , Inflamación , Degeneración del Disco Intervertebral/metabolismo , Degeneración del Disco Intervertebral/patología , Ratones , Ratones Endogámicos C57BL , Núcleo Pulposo/efectos de los fármacos , Núcleo Pulposo/metabolismo , Núcleo Pulposo/patología , Fenotipo , Transcriptoma/efectos de los fármacosRESUMEN
Inflammation response is an important reason for disc cell senescence during disc degeneration. Recently, melatonin is suggested to protect against disc degeneration. However, the effects of melatonin on annulus fibrosus (AF) cell senescence are not fully studied. The main purpose of this study was to investigate the effects of melatonin on AF cell senescence in an inflammatory environment and the underlying mechanism. Rat disc AF cells were cultured in a medium with tumor necrosis factor-α (TNF-α). Melatonin was added along with the medium to observe its protective effects. Compared with the control AF cells, TNF-α significantly declined cell proliferation potency and telomerase activity, elevated senescence-associated ß-galactosidase (SA-ß-Gal) activity, upregulated protein expression of senescence markers (p16 and p53), and increased reactive oxygen species (ROS) content and activity of the NF-κB pathway. However, when the TNF-α-treated AF cells were incubated with melatonin, ROS content and activity of the NF-κB pathway were decreased, and those parameters reflecting cell senescence indicated that AF cell senescence was also partly alleviated. Together, melatonin suppresses AF cell senescence through regulating the ROS/NF-κB pathway in an inflammatory environment. This study sheds a new light that melatonin may be promising to retard inflammation-caused disc degeneration.
Asunto(s)
Anillo Fibroso/efectos de los fármacos , Inflamación/tratamiento farmacológico , Degeneración del Disco Intervertebral/tratamiento farmacológico , Melatonina/farmacología , FN-kappa B/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Animales , Anillo Fibroso/metabolismo , Anillo Fibroso/patología , Antioxidantes/farmacología , Células Cultivadas , Senescencia Celular/efectos de los fármacos , Inflamación/metabolismo , Inflamación/patología , Degeneración del Disco Intervertebral/metabolismo , Degeneración del Disco Intervertebral/patología , Masculino , Modelos Animales , FN-kappa B/genética , Ratas , Ratas Sprague-Dawley , Telomerasa/metabolismo , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
BACKGROUND: Collagen cross-links contribute to the mechanical resilience of the intervertebral disc (IVD). UVA-light-activated riboflavin-induced collagen crosslinking (UVA-CXL) is a well-established and effective ophthalmological intervention that increases the mechanical rigidity of the collagen-rich corneal matrix in Keratoconus. This study explores the feasibility, safety and efficacy of translating this intervention in reinforcing the IVD. METHODS: Annulus fibrosus (AF) cells were isolated from bovine IVDs and treated with different combinations of riboflavin (RF) concentrations (0.05-8 mM) and UVA light intensities (0.3-4 mW/cm2). Metabolic activity (resazurin assay), cell viability (TUNEL assay), and gene expression of apoptosis regulators C-FOS and PT5 were assessed immediately and 24 hours after treatment. Biomechanical effects of UVA-CXL on IVDs were measured by indentation analysis of changes in the instantaneous modulus and by peel-force delamination strength analysis of the AF prior and after treatment. RESULTS: Different intensities of UVA did not impair the metabolic activity of AF cells. However, RF affected metabolic activity (p < 0.001). PT53 expression was similar in all RF conditions tested while C-FOS expression decreased 24 hours after treatment. Twenty-four hours after treatment, no apoptotic cells were observed in any condition tested. Biomechanical characterizations showed a significant increase in the annular peel strength of the UVA-CXL group, when compared to controls of UVA and RF alone (p < 0.05). UVA-CXL treated IVDs showed up to 152% higher (p < 0.001) instantaneous modulus values compared to the untreated control. CONCLUSION: This is the first study on UVA-CXL treatment of IVD. It induced significantly increased delamination strength and instantaneous modulus indentation values in intact IVD samples in a structure-function relationship. RF concentrations and UVA intensities utilized in ophthalmological clinical protocols were well tolerated by the AF cells. Our findings suggest that UVA-CXL may be a promising tool to reinforce the IVD matrix.
Asunto(s)
Colágeno/metabolismo , Riboflavina/química , Rayos Ultravioleta , Animales , Anillo Fibroso/citología , Anillo Fibroso/efectos de los fármacos , Anillo Fibroso/metabolismo , Anillo Fibroso/efectos de la radiación , Bovinos , Supervivencia Celular/efectos de la radiación , Colágeno/química , Estudios de Factibilidad , Expresión Génica/efectos de la radiación , Disco Intervertebral/citología , Mitocondrias/metabolismo , Mitocondrias/efectos de la radiación , Proteínas Proto-Oncogénicas c-fos/genética , Proteínas Proto-Oncogénicas c-fos/metabolismo , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
Deformity or fissure within the annulus fibrosus (AF) lamellar structure often results in disc herniation leading to the extrusion of nucleus pulposus (NP), which pushes the adjacent nerve, causing low back pain. Low back pain, frequently associated with the degeneration of the intervertebral disc (IVD), affects around 80% of the population worldwide. The difficulty in mimicking the unique structural characteristics of the native AF tissue presents several challenges to the tissue engineering field for the development of the long-term effective therapeutic strategy for AF tissue regeneration. The AF cell niche possesses less reparative capacity for regeneration and thus compels to develop a strategy to recapitulate damaged AF tissues. We have fabricated a polycaprolactone-supported electrocompacted type-I collagen patch (A-PCL-NH2+Col-I) using surface-modified electrospun-aligned polycaprolactone (A-PCL) nanofibers cross-linked with an electro-compacted type-I collagen patch (Col-I) using EDAC-NHS (1-ethyl-3-[3-(dimethylamino)propyl] carbodiimide hydrochloride and N-hydroxy succinimide). This subtle approach offered a 3D biodegradable scaffold with dense aggregates of anisotropic collagen-I nanofibrils coupled with electrospun-aligned PCL nanofibers, which provide high tensile strength (4.21 ± 1.07 MPa), moduli (24.496 ± 4.85 MPa), low subsidence to failure, and high-water absorption ability. The systemic organization of both the polymers within the scaffold, evident from attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, revealed a uniform degree of fiber alignment assessed by differential interference contrast (DIC) microscopy, field-emission scanning electron microscopy (FE-SEM), and cryo-SEM. The aminolysis of A-PCL nanofibers was established by energy-dispersive X-ray analysis (EDX), while circular dichroic spectra showed that the electro-compacted Col-I patch displayed a triple helical structure, characteristic of collagens. Moreover, the scaffold revealed more hydrophilic, rough nano-features, which provided ample ligands for cell attachment supporting adequate proliferation of primary goat annulus fibrosus (AF) cells, oriented along the fiber direction, and also favored sufficient production of collagen type-I (+32-fold change) and a glycosaminoglycan extracellular matrix (+2.3-fold change) as compared to cell control, respectively. This study thus demonstrates for the first time the practicability of creating an aligned polycaprolactone-supported electrocompacted type-I collagen hydrogel (A-PCL-NH2+Col-I) with significant biomechanical properties, which can be used as an alternative to repair and regenerate AF fissures in degenerated IVD.
Asunto(s)
Anillo Fibroso/efectos de los fármacos , Colágeno Tipo I/farmacología , Poliésteres/farmacología , Regeneración/efectos de los fármacos , Andamios del Tejido/química , Animales , Adhesión Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Colágeno Tipo I/química , Cabras , Nanofibras/química , Poliésteres/química , Ingeniería de Tejidos/métodosRESUMEN
Ferroptosis is a necrotic form of regulated cell death that was associated with lipid peroxidation and free iron-mediated Fenton reactions. It has been reported that iron deficiency had been implicated in the pathogenesis of intervertebral disc degeneration (IVDD) by activating apoptosis. However, the role of ferroptosis in the process of IVDD has not been illuminated. Here, we demonstrate the involvement of ferroptosis in IVDD pathogenesis. Our in vitro models show the changes in protein levels of ferroptosis marker and enhanced lipid peroxidation level during oxidative stress. Safranin O staining, hematoxylin-eosin staining, and immunohistochemical were used to assess the IVDD after 8 weeks of surgical procedure in vivo. Treatment with ferrostatin-1, deferoxamine, and RSL3 demonstrate the role of ferroptosis in tert-butyl hydroperoxide (TBHP)-treated annulus fibrosus cells (AFCs) and nucleus pulposus cells (NPCs). Ferritinophagy, nuclear receptor coactivator 4 (NCOA4)-mediated ferritin selective autophagy, is originated during the process of ferroptosis in response to TBHP treatment. Knockdown and overexpression NCOA4 further prove TBHP may induce ferroptosis of AFCs and NPCs in an autophagy-dependent way. These findings support a role for oxidative stress-induced ferroptosis in the pathogenesis of IVDD.
Asunto(s)
Anillo Fibroso/metabolismo , Ferroptosis , Degeneración del Disco Intervertebral/metabolismo , Núcleo Pulposo/metabolismo , Estrés Oxidativo , Animales , Anillo Fibroso/efectos de los fármacos , Anillo Fibroso/ultraestructura , Autofagia , Carbolinas/toxicidad , Estudios de Casos y Controles , Células Cultivadas , Deferoxamina/farmacología , Modelos Animales de Enfermedad , Ferroptosis/efectos de los fármacos , Humanos , Degeneración del Disco Intervertebral/genética , Degeneración del Disco Intervertebral/patología , Degeneración del Disco Intervertebral/prevención & control , Peroxidación de Lípido , Masculino , Coactivadores de Receptor Nuclear/genética , Coactivadores de Receptor Nuclear/metabolismo , Núcleo Pulposo/efectos de los fármacos , Núcleo Pulposo/ultraestructura , Estrés Oxidativo/efectos de los fármacos , Ratas Sprague-Dawley , Sideróforos/farmacología , Transducción de Señal , terc-Butilhidroperóxido/toxicidadRESUMEN
Constructing a biomimetic scaffold that replicates the complex architecture of intervertebral disc annulus fibrosus (AF) remains a major goal in AF tissue engineering. In this study, a biomimetic angle-ply multi-lamellar polycaprolactone/silk fibroin (PCL/SF) AF scaffold was fabricated. Wet-spinning was used to obtain aligned PCL/SF microfiber sheets, and these were excised into strips with microfibers aligned at +30° or -30° relative to the strip long axis. This was followed by stacking two strips with opposing fiber alignment and wrapping them concentrically around a mandrel. Our results demonstrated that the scaffold possessed spatial structure and mechanical properties comparable to natural AF. The scaffold supported rabbit AF cells adhesion, proliferation, infiltration and guided oriented growth and extracellular matrix deposition. In conclusion, our angle-ply multi-lamellar scaffold offers a potential solution for AF replacement therapy and warrants further attention in future investigations.
Asunto(s)
Anillo Fibroso/citología , Materiales Biomiméticos , Ingeniería de Tejidos/instrumentación , Andamios del Tejido/química , Animales , Anillo Fibroso/efectos de los fármacos , Anillo Fibroso/fisiología , Materiales Biomiméticos/síntesis química , Materiales Biomiméticos/química , Materiales Biomiméticos/farmacología , Biomimética/instrumentación , Biomimética/métodos , Células Cultivadas , Matriz Extracelular/metabolismo , Disco Intervertebral/citología , Disco Intervertebral/fisiología , Ensayo de Materiales , Poliésteres/síntesis química , Poliésteres/química , Conejos , Espectroscopía Infrarroja por Transformada de Fourier , Propiedades de Superficie , Ingeniería de Tejidos/métodosRESUMEN
Back pain is a leading cause of global disability associated with intervertebral disc (IVD) pathologies. Discectomy alleviates disabling pain caused by IVD herniation without repairing annulus fibrosus (AF) defects, which can cause accelerated degeneration and recurrent pain. Biological therapies show promise for IVD repair but developing high-modulus biomaterials capable of providing biomechanical stabilisation and delivering biologics remains an unmet challenge. The present study identified critical factors and developed an optimal formulation to enhance the delivery of AF cells and transforming growth beta-3 (TGFß-3) in genipin-crosslinked fibrin (FibGen) hydrogels. Part 1 showed that AF cells encapsulated in TGFß-3-supplemented high-modulus FibGen synthesised little extracellular matrix (ECM) but could release TGFß-3 at physiologically relevant levels. Part 2 showed that AF cells underwent apoptosis when encapsulated in FibGen, even after reducing fibrin concentration from 70 to 5 mg/mL. Mechanistic experiments, modifying genipin concentration and integrin binding site presence demonstrated that genipin crosslinking caused AF cell apoptosis by inhibiting cell-biomaterial binding. Adding integrin binding sites with fibronectin partially rescued apoptosis, indicating genipin also caused acute cytotoxicity. Part 3 showed that FibGen formulations with 1 mg/mL genipin had enhanced ECM synthesis when supplemented with fibronectin and TGFß-3. In conclusion, FibGen could be used for delivering biologically active compounds and AF cells, provided that formulations supplied additional sites for cell-biomaterial binding and genipin concentrations were low. Results also highlighted a need for developing strategies that protect cells against acute crosslinker cytotoxicity to overcome challenges of engineering high-modulus cell carriers for musculoskeletal tissues that experience high mechanical demands.
Asunto(s)
Anillo Fibroso/patología , Apoptosis , Reactivos de Enlaces Cruzados/química , Fibrina/química , Hidrogeles/química , Iridoides/química , Factor de Crecimiento Transformador beta3/farmacología , Animales , Anillo Fibroso/efectos de los fármacos , Apoptosis/efectos de los fármacos , Bovinos , Uniones Célula-Matriz/efectos de los fármacos , Uniones Célula-Matriz/metabolismo , Matriz Extracelular/efectos de los fármacos , Matriz Extracelular/metabolismo , Fibronectinas/farmacología , Humanos , CinéticaRESUMEN
AIM: To investigate the effects of metformin, a drug used widely for the treatment of type 2 diabetes mellitus, on human primary cell cultures prepared from uninjured segment of disc material intervertebral disk tissues. MATERIAL AND METHODS: Primary cell cultures were prepared using the tissues of six patients (three males and three females) who had undergone lumbar microdiscectomy and sequestrectomy. Untreated samples served as the control group, and metformintreated samples served as the experimental group. All the samples were evaluated using an inverted light microscope, acridine orange/propidium iodide staining (AO/PI), and a fluorescence microscope. The cytostatic and cytotoxic effects of metformin, which was administered to the samples using a commercial MTT assay kit, were also evaluated. The data obtained were statistically assessed, and the alpha significance value was accepted as less than 0.05. In addition, for the groupsâ™ changes in the expressions of chondroadherin (CHAD), cartilage oligomeric matrix protein (COMP), interleukin-1β (IL-1β) matrix metalloproteinase 7 (MMP-7), and matrix metalloproteinase 19 (MMP-19), genes related to the extracellular matrix synthesis and degradation were determined using gene-specific TaqMan Gene Expression Assays. RESULTS: The administration of the drug adversely affected nucleus pulposus (NP)/annulus fibrosus (AF) cells and extracellular matrixâ"like structures. This was statistically significant (p < 0.05). CONCLUSION: Clinicians should not disregard the adverse effects of metformin, which is used widely in clinical practice, on the components of intervertebral disk tissues.
Asunto(s)
Anillo Fibroso/efectos de los fármacos , Hipoglucemiantes/toxicidad , Metformina/toxicidad , Núcleo Pulposo/efectos de los fármacos , Anillo Fibroso/metabolismo , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Femenino , Expresión Génica/efectos de los fármacos , Humanos , Masculino , Núcleo Pulposo/metabolismoRESUMEN
Appropriate cell sources, bioactive factors and biomaterials for generation of functional and integrated annulus fibrosus (AF) tissue analogues are still an unmet need. In the present study, the AF cell markers, collagen type I, cluster of differentiation 146 (CD146), mohawk (MKX) and smooth muscle protein 22α (SM22α) were found to be suitable indicators of functional AF cell induction. In vitro 2D culture of human AF cells showed that transforming growth factor ß1 (TGF-ß1) upregulated the expression of the functional AF markers and increased cell contractility, indicating that TGF-ß1-pre-treated AF cells were an appropriate cell source for AF tissue regeneration. Furthermore, a tissue engineered construct, composed of polyurethane (PU) scaffold with a TGF-ß1-supplemented collagen type I hydrogel and human AF cells, was evaluated with in vitro 3D culture and ex vivo preclinical bioreactor-loaded organ culture models. The collagen type I hydrogel helped maintaining the AF functional phenotype. TGF-ß1 supplement within the collagen I hydrogel further promoted cell proliferation and matrix production of AF cells within in vitro 3D culture. In the ex vivo IVD organ culture model with physiologically relevant mechanical loading, TGF-ß1 supplement in the transplanted constructs induced the functional AF cell phenotype and enhanced collagen matrix synthesis. In conclusion, TGF-ß1-containing collagen-PU constructs can induce the functional cell phenotype of human AF cells in vitro and in situ. This combined cellular, biomaterial and bioactive agent therapy has a great potential for AF tissue regeneration and rupture repair.
Asunto(s)
Anillo Fibroso/patología , Colágeno/farmacología , Poliuretanos/farmacología , Andamios del Tejido/química , Factor de Crecimiento Transformador beta1/farmacología , Cicatrización de Heridas/efectos de los fármacos , Adulto , Animales , Anillo Fibroso/efectos de los fármacos , Biomarcadores/metabolismo , Bovinos , Células Cultivadas , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Técnicas de Cultivo de Órganos , Fenotipo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Rotura , Cicatrización de Heridas/genéticaRESUMEN
OBJECTIVE: To explore if chemokine (C-C motif) ligand 5 (CCL5) delivery could recruit annulus fibrosus (AF) cells to the injury sites and facilitate the repair of ruptured AF. DESIGN: The effects of CCL5 on bovine AF cells in vitro were tested by transwell assay and quantitative real-time polymerase chain reaction. Fibrin gel containing CCL5 was used to treat annulotomized bovine caudal discs cultured under dynamic loading conditions. After 14 days of loading, the samples were collected for histological examination. A pilot animal study was performed using sheep cervical discs to investigate the effect of fibrin gel encapsulated with CCL5 for the treatment of ruptured AF. After 14 weeks, the animals were sacrificed, and the discs were scanned with magnetic resonance imaging before histopathological examination. RESULTS: CCL5 showed a chemotactic effect on AF cells in a dose-dependent manner. AF cells cultured with CCL5 in vitro did not show any change of the gene expression of CCL5 receptors, catabolic and proinflammatory markers. In vitro release study showed that CCL5 exhibited sustained release from the fibrin gel into the culture media; however, in the organ culture study CCL5 did not stimulate homing of AF cells toward the defect sites. The pilot animal study did not show any repair effect of CCL5. CONCLUSIONS: CCL5 has a chemotactic effect on AF cells in vitro, but no ex vivo or in vivo regenerative effect when delivered within fibrin gel. Further study with a stronger chemotactic agent and/or an alternate biomaterial that is more conductive of cell migration is warranted.
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Materiales Biocompatibles/farmacología , Quimiocina CCL5/farmacología , Fibrina/administración & dosificación , Disco Intervertebral/efectos de los fármacos , Regeneración/efectos de los fármacos , Animales , Anillo Fibroso/efectos de los fármacos , Bovinos , Movimiento Celular/efectos de los fármacos , Células Cultivadas , Modelos Animales de Enfermedad , Sistemas de Liberación de Medicamentos/métodos , Geles , Técnicas de Cultivo de Órganos , Proyectos Piloto , Receptores CCR5/efectos de los fármacos , OvinosRESUMEN
The present study aimed to investigate the mechanism of intervertebral disc degeneration (IVDD) and identify an efficient treatment for low back pain. Rabbit annulus fibrosus stem cells (AFSCs) were treated with metformin and lipopolysaccharide (LPS). The results indicated that LPS induced HMGB1 release from the nuclei of AFSCs and caused cell senescence in a concentration-dependent manner. The production of PGE2 and HMGB1 was increased in the medium of the LPS-treated AFSCs. Certain inflammation-associated genes (IL-ß1, IL-6, COX-2 and TNF-α) and proteins (IL-ß1, COX-2 and TNF-α) and specific catabolic genes (MMP-3 and MMP-13) exhibited increased expression in LPS-treated AFSCs. However, the expression levels of other anabolic genes, such as collagen I and collagen II were decreased in LPS-treated AFSCs. Following addition of metformin to LPS-containing medium, HMGB1 was retained in the nuclei of AFSCs and the production of PGE2 and HMGB1 was reduced. The expression levels of the catabolic genes and proteins were decreased and those of the anabolic genes were increased. The findings indicated that metformin exerted an anti-inflammatory effect by blocking the HMGB1 translocation and by inhibiting catabolic production and cell senescence in AFSCs. Therefore, metformin may be used as an efficient treatment for the disc degenerative disease.
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Anillo Fibroso/efectos de los fármacos , Antiinflamatorios/farmacología , Proteína HMGB1/metabolismo , Degeneración del Disco Intervertebral/metabolismo , Metformina/farmacología , Animales , Anillo Fibroso/metabolismo , Senescencia Celular/efectos de los fármacos , Proteína HMGB1/efectos de los fármacos , Inflamación/inducido químicamente , Inflamación/metabolismo , Lipopolisacáridos/toxicidad , Conejos , Células Madre/efectos de los fármacos , Células Madre/metabolismoRESUMEN
BACKGROUND: The aim of this study is to explore the effects of TGF-ß1 on autophagy and apoptosis induced by exogenous hydrogen peroxide (H2O2) in annulus fibrosus (AF) cells and possible signal pathways involved in this process. METHODS: AF cells were isolated from rat lumbar discs and subjected to different concentrations of exogenous H2O2 (50, 100, 200 µmol/L) for different time periods (0.5, 1, 2, and 4 h). Cell viability was determined by CCK-8 assay, and the levels of autophagy and apoptosis were evaluated by Western blotting and caspase 3, 8, 9 activity assay. By administration with different concentrations of TGF-ß1 (5, 10, 20 ng/mL), the effects of TGF-ß1 on autophagy and apoptosis induced by H2O2 were observed, and the possible signaling pathways were also investigated by using various apoptosis inhibitors or an autophagy inhibitor Bafilomycin A (Baf A) in AF cells. RESULTS: H2O2 significantly impaired cell viability in a dose- and time-dependent manner. H2O2 also induced a sudden and the highest level of autophagy at 1 h, and gradually increased apoptosis through ERK pathway. The mitochondrial pathway was involved in H2O2-induced apoptosis in AF cells. TGF-ß1 reduced the expression of p-ERK and downregulated the expressions of Beclin-1, LC3 II/I, and mitochondrial-related apoptotic proteins (Bax/Bcl-2, caspase-9). Meanwhile, TGF-ß1 downregulated the level of intracellular H2O2 through upregulating the expression level of glutathione peroxidase-1 (GPx-1). CONCLUSIONS: TGF-ß1 reduced autophagy and apoptosis induced by exogenous H2O2 through downregulating the expression of ERK in AF cells. TGF-ß1 could downregulate the level of ERK and intracellular H2O2 by upregulating GPx-1.
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Anillo Fibroso/metabolismo , Autofagia/fisiología , Sistema de Señalización de MAP Quinasas/fisiología , Estrés Oxidativo/fisiología , Factor de Crecimiento Transformador beta1/farmacología , Animales , Anillo Fibroso/efectos de los fármacos , Anillo Fibroso/patología , Autofagia/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/fisiología , Relación Dosis-Respuesta a Droga , Peróxido de Hidrógeno/toxicidad , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Masculino , Estrés Oxidativo/efectos de los fármacos , Ratas , Ratas Sprague-DawleyRESUMEN
BACKGROUND: Disc degeneration (DD) is one of the common diseases worldwide, which deeply influences normal life and leads to excruciating pain. However, an effective treatment for DD is still not identified. METHOD: The present study systemically examined the effect of melatonin on annulus fibrosus (AF) cells of patients with DD. RESULTS: Melatonin had the effect of promoting proliferation, inducing autophagy, and suppressing apoptosis on AF cells of patients with DD. Moreover, melatonin contributed to the translation and transcription of autophagy-related protein ATG7 and inhibited the function of miR-106a-5p in AF cells. In addition, the results suggested that miR-106a-5p mediated the expression of ATG7 by directly binding to its 3'UTR in AF cells. CONCLUSION: This research not only gained a deep insight of melatonin mode of action, but also indicated its potential target signaling pathway in AF cells.
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Anillo Fibroso , Proteína 7 Relacionada con la Autofagia/metabolismo , Proliferación Celular , Degeneración del Disco Intervertebral , Melatonina , MicroARNs/metabolismo , Anillo Fibroso/efectos de los fármacos , Anillo Fibroso/metabolismo , Anillo Fibroso/patología , Antioxidantes/metabolismo , Antioxidantes/farmacología , Apoptosis/efectos de los fármacos , Apoptosis/fisiología , Proliferación Celular/efectos de los fármacos , Proliferación Celular/fisiología , Células Cultivadas , Humanos , Degeneración del Disco Intervertebral/metabolismo , Degeneración del Disco Intervertebral/patología , Melatonina/metabolismo , Melatonina/farmacología , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiología , Resultado del TratamientoRESUMEN
The aim of this study was to ascertain whether, like many cell types in cartilaginous tissues if type XI collagen was a pericellular component of annulus fibrosus (AF) cells and chondrocytes. Fine fibrillar networks were visualised which were perlecan, HS (MAb 10E4) and type XI collagen positive. Heparitinase-III pre-digestion abolished the type XI collagen and 10E4 localisation in these fibrillar assemblies demonstrating a putative HS mediated interaction which localised the type XI collagen. Type XI collagen was confirmed to be present in the Heparitinase III treated AF monolayer media samples by immunoblotting. Heparitinase-III generated ΔHS stub epitopes throughout these fibrillar networks strongly visualised by MAb 3-G-10. Monolayers of murine hip articular chondrocytes from C57BL/6 and Hspg2 exon 3 null mice also displayed pericellular perlecan localisations, however type XI collagen was only evident in the Wild type mice. Perlecan was also immunolocalised in control and murine knee articular cartilage from the two mouse genotypes subjected to a medial meniscal destabilisation procedure which induces OA. This resulted in a severe depletion of perlecan levels particularly in the perlecan exon 3 null mice and was consistent with OA representing a disease of the pericellular matrix. A model was prepared to explain these observations between the NPP type XI collagen domain and HS chains of perlecan domain-I in the pericellular matrix of AF cells which likely contributed to cellular communication, tissue stabilization and the regulation of extracellular matrix homeostasis.
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Anillo Fibroso/efectos de los fármacos , Colágeno Tipo XI/genética , Proteoglicanos de Heparán Sulfato/genética , Animales , Anillo Fibroso/metabolismo , Anillo Fibroso/patología , Cartílago Articular/crecimiento & desarrollo , Cartílago Articular/metabolismo , Condrocitos/efectos de los fármacos , Condrocitos/metabolismo , Exones/genética , Matriz Extracelular/genética , Proteínas de la Matriz Extracelular/genética , Homeostasis/genética , Disco Intervertebral/crecimiento & desarrollo , Disco Intervertebral/metabolismo , Ratones , Polisacárido Liasas/farmacologíaRESUMEN
Focal defects in the annulus fibrosus (AF) of the intervertebral disc (IVD) arising from herniation have detrimental impacts on the IVD's mechanical function. Thus, biomimetic-based repair strategies must restore the mechanical integrity of the AF to help support and restore native spinal loading and motion. Accordingly, an annulus fibrosus repair patch (AFRP); a collagen-based multi-laminate scaffold with an angle-ply architecture has been previously developed, which demonstrates similar mechanical properties to native outer AF (oAF). To further enhance the mimetic nature of the AFRP, interlamellar (ILM) glycosaminoglycan (GAG) was incorporated into the scaffolds. The ability of the scaffolds to withstand simulated impact loading and resist herniation of native IVD tissue while contributing to the restoration of spinal kinematics were assessed separately. The results demonstrate that incorporation of a GAG-based ILM significantly increased (pâ¯<â¯0.001) the impact strength of the AFRP (2.57⯱â¯0.04â¯MPa) compared to scaffolds without (1.51⯱â¯0.13â¯MPa). Additionally, repair of injured functional spinal units (FSUs) with an AFRP in combination with sequestering native NP tissue and a full-thickness AF tissue plug enabled the restoration of creep displacement (pâ¯=â¯0.134), short-term viscous damping coefficient (pâ¯=â¯0.538), the long-term viscous (pâ¯=â¯0.058) and elastic (pâ¯=â¯0.751) damping coefficients, axial neutral zone (pâ¯=â¯0.908), and axial range of motion (pâ¯=â¯0.476) to an intact state. Lastly, the AFRP scaffolds were able to prevent native IVD tissue herniation upon application of supraphysiologic loads (5.28⯱â¯1.24â¯MPa). Together, these results suggest that the AFRP has the strength to sequester native NP and AF tissue and/or implants, and thus, can be used in a composite repair strategy for IVDs with focal annular defects thereby assisting in the restoration of spinal kinematics.