Primary cilia support cartilage regeneration after injury / 国际口腔科学杂志·英文版

In growing children, growth plate cartilage has limited self-repair ability upon fracture injury always leading to limb growth arrest. Interestingly, one type of fracture injuries within the growth plate achieve amazing self-healing, however, the mechanism is unclear. Using this type of fracture mouse model, we discovered the activation of Hedgehog (Hh) signaling in the injured growth plate, which could activate chondrocytes in growth plate and promote cartilage repair. Primary cilia are the central transduction mediator of Hh signaling. Notably, ciliary Hh-Smo-Gli signaling pathways were enriched in the growth plate during development. Moreover, chondrocytes in resting and proliferating zone were dynamically ciliated during growth plate repair. Furthermore, conditional deletion of the ciliary core gene Ift140 in cartilage disrupted cilia-mediated Hh signaling in growth plate. More importantly, activating ciliary Hh signaling by Smoothened agonist (SAG) significantly accelerated growth plate repair after injury. In sum, primary cilia mediate Hh signaling induced the activation of stem/progenitor chondrocytes and growth plate repair after fracture injury.

The role of under-investigated connexins in musculoskeletal tissue: a brief review with emphasis on bone tissue / El papel de las escasamente investigadas conexinas en el tejido músculo-esquelético: una breve revisión con énfasis en el tejido óseo

Connexins (Cxs) are a family of transmembrane proteins that form gap junctions and hemi-channels, which mediate cell-cell communication between neighboring cells and the respective extracellular milieu in different tissues. Most tissues and cell types throughout the body express one or more Cx proteins, highlighting its importance in regulating cell growth, differentiation, adhesion, migration, cell death and others. Moreover, Cx can propagate intracellular signals through its C-terminus domain, and thus function beyond a mere channel. Cx43 is the most highly expressed and most well studied Cx in bone and musculoskeletal tissues, although Cx40, Cx45, Cx46 and more recently, the Cx37 have been described in bone tissue, along with Cx26, Cx32 and Cx39 in other musculoskeletal tissues. Here, we discuss the basic structure of gap junctions and the role of the Cxs in musculoskeletal tissue, with special focus on Cx37. (AU)

Las conexinas (Cxs) son una familia de proteínas transmembrana que forman uniones en hendidura y hemicanales encargados de mediar la comunicación entre células vecinas y el respectivo medio extracelular en diferentes tejidos. La mayoría de los tejidos y células expresan una o más proteínas conexina, jugando un papel importante en la regulación de la proliferación celular, diferenciación, adhesión, migración y muerte celular, entre otras funciones. Además de actuar como un canal, las conexinas pueden propagar señales intracelulares a través del dominio C-terminal. La Cx43 es la conexina mas expresada y mejor estudiada en el tejido óseo y el músculo, aunque las Cx40, Cx45, Cx46, y mas recientemente Cx37, son también detectadas en el hueso. A su vez la expresión de la Cx26, Cx32 y Cx39 ha sido observada en otros tejidos músculoesqueléticos. En este manuscrito describimos la estructura básica de las uniones tipo gap y el papel que las Cxs, y en especial la Cx37, tienen en tejidos músculo-esqueléticos. (AU)

The Relationship between HIF-2α and VEGF with Radiographic Severity in the Primary Osteoarthritic Knee

PURPOSE: The aim of this study was to determine the relationship of hypoxia-inducible factor-2 (HIF-2α) and vascular endothelial growth factor (VEGF) with radiographic severity in primary osteoarthritis (OA) of the knee. Expression of these two factors in cartilage samples from OA knee joints was examined at mRNA and protein levels. MATERIALS AND METHODS: Knee joints were examined using plain radiographs, and OA severity was assessed using the Kellgren and Lawrence (KL) grading system. Specimens were collected from 29 patients (31 knees) who underwent total knee replacement because of severe medial OA of the knee (KL grades 3 and 4), 16 patients who underwent knee arthroscopy (KL grade 2), and 5 patients with traumatic knees (KL grade 0). HIF-2α and VEGF expression was quantified by real-time polymerase chain reaction and western blotting. RESULTS: Cartilage degeneration correlated with the radiographic severity grade. OA severity, determined using the Mankin scale, correlated positively with the KL grade (r=0.8790, p<0.01), and HIF-2α and VEGF levels with the radiographic severity of knee OA (r=0.7001, p<0.05; r=0.6647, p<0.05). CONCLUSION: In OA cartilage, HIF-2α and VEGF mRNA and protein levels were significantly and positively correlated. The expression of both factors correlated positively with the KL grade. HIF-2α and VEGF, therefore, may serve as biochemical markers as well as potential therapeutic targets in knee OA.

Lentiviral-mediated RNAi targeting caspase-3 inhibits apoptosis induced by serum deprivation in rat endplate chondrocytes in vitro

Current studies find that degenerated cartilage endplates (CEP) of vertebrae, with fewer diffusion areas, decrease nutrient supply and accelerate intervertebral disc degeneration. Many more apoptotic cells have been identified in degenerated than in normal endplates, and may be responsible for the degenerated grade. Previous findings suggest that inhibition of apoptosis is one possible approach to improve disc regeneration. It is postulated that inhibition of CEP cell apoptosis may be responsible for the regeneration of endplates. Caspase-3, involved in the execution phase of apoptosis, is a candidate for regulating the apoptotic process. In the present study, CEP cells were incubated in 1% fetal bovine serum. Activated caspases were detected to identify the apoptotic pathway, and apoptosis was quantified by flow cytometry. Lentiviral caspase-3 short hairpin RNA (shRNA) was employed to study its protective effects against serum deprivation. Silencing of caspase-3 expression was quantified by reverse transcription-polymerase chain reaction and Western blots, and inhibition of apoptosis was quantified by flow cytometry. Serum deprivation increased apoptosis of rat CEP cells through activation of a caspase cascade. Lentiviral caspase-3 shRNA was successfully transduced into CEP cells, and specifically silenced endogenous caspase-3 expression. Surviving cells were protected by the downregulation of caspase-3 expression and activation. Thus, lentiviral caspase-3 shRNA-mediated RNAi successfully silenced endogenous caspase-3 expression, preventing inappropriate or premature apoptosis.

Delivery of the Sox9 gene promotes chondrogenic differentiation of human umbilical cord blood-derived mesenchymal stem cells in an in vitro model

SRY-related high-mobility-group box 9 (Sox9) gene is a cartilage-specific transcription factor that plays essential roles in chondrocyte differentiation and cartilage formation. The aim of this study was to investigate the feasibility of genetic delivery of Sox9 to enhance chondrogenic differentiation of human umbilical cord blood-derived mesenchymal stem cells (hUC-MSCs). After they were isolated from human umbilical cord blood within 24 h after delivery of neonates, hUC-MSCs were untreated or transfected with a human Sox9-expressing plasmid or an empty vector. The cells were assessed for morphology and chondrogenic differentiation. The isolated cells with a fibroblast-like morphology in monolayer culture were positive for the MSC markers CD44, CD105, CD73, and CD90, but negative for the differentiation markers CD34, CD45, CD19, CD14, or major histocompatibility complex class II. Sox9 overexpression induced accumulation of sulfated proteoglycans, without altering the cellular morphology. Immunocytochemistry demonstrated that genetic delivery of Sox9 markedly enhanced the expression of aggrecan and type II collagen in hUC-MSCs compared with empty vector-transfected counterparts. Reverse transcription-polymerase chain reaction analysis further confirmed the elevation of aggrecan and type II collagen at the mRNA level in Sox9-transfected cells. Taken together, short-term Sox9 overexpression facilitates chondrogenesis of hUC-MSCs and may thus have potential implications in cartilage tissue engineering.

MicroRNA-21 controls the development of osteoarthritis by targeting GDF-5 in chondrocytes

Osteoarthritis is a common cause of functional deterioration in older adults and is an immense burden on the aging population. Altered chondrogenesis is the most important pathophysiological process involved in the development of osteoarthritis. However, the molecular mechanism underlying the regulation of chondrogenesis in patients with osteoarthritis requires further elucidation, particularly with respect to the role of microRNAs. MiR-21 expression in cartilage specimens was examined in 10 patients with knee osteoarthritis and 10 traumatic amputees. The effect of miR-21 on chondrogenesis was also investigated in a chondrocyte cell line. The effect of miR-21 on the expression of growth differentiation factor 5 (GDF-5) was further assessed by luciferase reporter assay and western blot. We found that endogenous miR-21 is upregulated in osteoarthritis patients, and overexpression of miR-21 could attenuate the process of chondrogenesis. Furthermore, we identified GDF-5 as the direct target of miR-21 during the regulation of chondrogenesis. Our data suggest that miR-21 has an important role in the pathogenesis of osteoarthritis and is a potential therapeutic target.

Effect of chinese traditional herb Epimedium grandiflorum C.Morren and its extract Icariin on osteoarthritis via suppressing NF-kB pathway.

Osteoarthritis (OA), which is also called degenerative arthritis, is the leading cause of disabilities in the old people. The Chinese traditional herb Epimedium grandiflorum had long been found to attenuate osteoarthritis process, but the detailed mechanism was not clear. To study the mechanisms of E. grandiflorum in the treatment of osteoarthritis, rabbit osteoarthritis model combined with D-galactose was used. After different treatments for 10 weeks, cartilage sections were analyzed by immunohistochemistry for uPA, uPAR and PAI expression level. E. grandiflorum could significantly attenuate OA condition and decrease uPA, uPAR and PAI expression. The extract of E. grandiflorum, icariin also had a similar effect when compared with E. grandiflorum treatment alone. Rabbit chondrocytes were further isolated to be stimulated by TNFα combined with different reagents treatment. Here, icariin treatment significantly reduced nuclear factor kappa B NF-B (P65) activity, decreased uPA expression level and increased IBα protein level. The results indicated that E. grandiflorum and its extract icariin could attenuate OA condition, reduce the expression of uPA and uPAR and increase PAI in experimental rabbit model and this effect may be conducted by suppressing NF-kB activity by increasing IkBα level.

Bone and Cartilage Turnover Markers, Bone Mineral Density, and Radiographic Damage in Men with Ankylosing Spondylitis

PURPOSE: To determine the levels of bone and cartilage turnover markers in men with ankylosing spondylitis (AS) and to investigate their associations with disease activity, bone mineral density, and radiographic damage of the spine. PATIENTS AND METHODS: This cross-sectional study enrolled 35 men with newly diagnosed AS. The bone mineral densities (BMD) of their lumbar spines and proximal femurs, Bath AS Disease Activity Index (BASDAI), and Bath AS Radiographic Index (BASRI) were evaluated. Urinary C-terminal telopeptide fragments of type I collagen (CTX-I) and type II collagen (CTX-II) levels were determined by enzyme-linked immunosorbent assay, and serum levels of bone-specific alkaline phosphatase (BALP) and osteocalcin were determined by an enzyme immunoassay. Levels of biochemical markers were compared with those of 70 age-matched healthy men. RESULTS: Patients with AS had significantly higher mean urinary CTX-I and CTX-II levels than control subjects (p < 0.05). Elevated urinary CTX-I levels correlated well with BASDAI, femoral BMD, and femoral T score (p < 0.05), and elevated urinary CTX-II levels correlated well with spinal BASRI (p < 0.05) in patients with AS. Mean serum BALP and osteocalcin levels did not differ between patients and controls and did not show any significant correlations with BMD, BASDAI, or BASRI in men with AS. Conclusions: Elevated CTX-I reflects disease activity and loss of femoral BMD while elevated CTX-II levels correlate well with radiographic damage of the spine, suggesting the usefulness of these markers for monitoring disease activity, loss of BMD, and radiographic damage in men with AS.

Tissue engineering of cartilage with porous polycarprolactone--alginate scaffold: the first report of tissue engineering in Thailand.

OBJECTIVE: To engineer human cartilage with porous polycaprolactone (PCL)-Alginate Scaffold. BACKGROUND: Polycaprolactone (PCL) is a prolonged degradable polymer that has good mechanical strength. The authors fabricated PCL as an ear shaped scaffold. Alginate hydrogel was used to seed chondrocyte into the PCL porous scaffold by a gel-cell seeding technique. MATERIAL AND METHOD: PCL Scaffolds were fabricated like human pinna by particle leaching technique. Chondrocyte was isolated from human rib cartilage and then cultured. The cultured chondrocyte were mixed with 1.2% alginate and b-FGF (basic-fibroblast growth factor) 5 ng/ml at a concentration of 25 x 10(6) cell/ml, then were seeded in porous PCL scaffold to make the constructs. The constructs were cultured in vitro for 1 week. Then they were implanted in subcutaneous plane of the back of six-female nude mice (5 weeks old). Two nude mice were sacrificed at 2, 3, and 6 months. Histological study was done (H&E, Alcian blue, collagen type II). RESULT: Neocartilage was formed in the porous cavity of PCL scaffold. At 2 and 3 months, neocartilage were similar to very young cartilage. At 6 months, they were mature. The delayed maturation until 6 months and the highly vascularization of neocartilage in the early phase was the effect of human b-FGF The growths of neocartilage islands in porous cavity were also observed along with degradation ofPCL inter-porous septum. CONCLUSION: This paper reports the first success of cartilage tissue engineering in Thailand.

Marcadores séricos de cartilagem na artrite reumatóide avançada / Serum cartilage biomarkers in late rheumatoid arthritis

O objetivo deste trabalho foi avaliar o valor clínico de dois novos marcadores séricos de cartilagem em pacientes com artrite reumatóide crônica. Cento e quarenta pacientes foram seguidos por um período médio de 12 anos e avaliados para a presença de glicoproteína-39 de cartilagem humana e para matrix de proteína oligomérica sérica e seu respectivo coeficiente de correlação entre os marcadores e um escore de atividade da doença. Os valores médios da matrix de proteína oligomérica sérica e glicoproteína-39 de cartilagem humana foram, respectivamente, 9 ± 6 ug/ml e 36 ± 16 ug/ml (p > 0,001) quando comparados aos controles. Uma correlação positiva foi observada entre os escores de atividade da doença e os biomarcadores (r = 0,67 para a glicoproteína-39 de cartilagem humana e r = 0,83 para a matrix de proteína oligomérica sérica). Conclusão: O presente estudo mostrade maneira inequívoca que pacientes com artrite reumatóide de longa duração mostram valores séricos mais elevados de marcadores bioquímicos do metabolismo da cartilagem e umacorrelação positiva com o escore de atividade da doença.

Correlation between PMI and DNA degradation of costicartilage and dental pulp cells in human being / 法医学杂志

OBJECTIVE@#To probe the correlation between the postmortem interval (PMI) and the DNA degradation of costicartilage and dental pulp cells in human being after death, and to seek a new method for estimating PMI.@*METHODS@#The image cytometry was used to measure the DNA degradation under different ambient temperatures (30-35 degrees C, 15-20 degrees C) in 0-15 days after death.@*RESULTS@#The average DNA content of two kinds of tissue was degradated with the prolongation of PMI. But there was a plateau period of 0-4 days for dental pulp cells of human being in 15-20 degrees C. There was a high negative correlativity P<0.01 between the average DNA content and PMI.@*CONCLUSION@#PMI could be estimated accurately according to the DNA degradation of costicartilage and dental pulp cells in human being after death.

Serum and synovial fluid chondroitin sulfate and keratan sulfate in osteoarthritis and rheumatoid arthritis

This study was performed to quantitate serum and synovial fluid chondroitin sulfate and keratan sulfate levels in patients with rheumatoid arthritis [RA] and osteoarthritis [OA] as well as levels in control sera and synovial fluid to evaluate their reflection of the disease process. This study was conducted on 22 RA patients, 22 OA patients and 10 control subjects. We measured serum and synovial level of chondroittn sulfate [CS] and Keratan sulfate [KS] and correlated their levels to the disease activity, our results slowed that serum KS levels were higher in patients with arthritic conditions than in controls [P < 0.05] No correlation was found between age, disease activity and CRP in RA and sera CS or KS. So measuring these markers may be valuable for evaluating the arthritic conditions

Insulin-like growth factor- 1 in the pathogenesis of ostesarthitis

The destructive process of the articular cartilage in osteoarthritis has a complex pathogenesis. Although the view was originally held that only cartilage loss occurs in osteoarthritis, it has been shown that cartilage metabolism is also increased, leading to increased synthesis of proteoglycans and collagen. This increased anabolic activity is seen as an attempt to repair the cartilage damage and might slow net cartilage loss. It is therefore of interest to study the factors that stimulate cartilage synthesis. One of these could be insulin-like growth factor-1. Recent experimental and clinical studies provide evidence for the pathogenic role of insulin-related growth factor-1

Interaction of concanavalin A with sugar residues of collagen from different tissues

Particularidades topoquímicas da reaçäo de diferentes tipos de estruturas contendo colágeno, com Cancanavalina A (Con A) näo tem sido considerados até agora. A presença de disponibilidade de resíduos de glicose em moléculas de colágeno de intestino, fígado, cartilagem e tendäo säo verificados usando Con A e peroxidase de rábano silvestre (HRP). Em cortes de intestino, cartilagem e tendäo, o método usando Con A-HRP só foi significativamente positivo quando os cortes eram submetidos a um tratamento prévio com papaína sugerindo a presença de glicoproteínas e proteoglicanas da matriz extracelular (ECM), interagindo com resíduos laterais de carboidratos das moléculas de colágeno ou causando algum bloqueio estérico como ocorre em regiöes com alto estado de compactaçäo

Effect of total food deprivation on the proteoglycans of rat hyaline cartilage and bone

Hay hipótesis que sugieren que el efecto de la privación total de alimentos sobre el hueso ocurre por alteraciones en la síntesis de la matriz orgánica. Este trabajo se llevó a cabo con el propósito de caracterizar las posibles alteraciones en las propiedades de los proteoglucanos de cartílago hialino y hueso de rata como resultado de un ayuno total. Ratas macho de la cepa Wistar fueron separadas aleatoriamente y asignadas a un grupo control que comió y bebió "ad libitum" o a un grupo experimental que únicamente bebió agua. Los animales fueron pesados y sacrificados a los 4 u 8 días de iniciada la experiencia después de administrarles una dosis de 35S(-SO4-). Se aislaron los PG de los fémures y cartílagos xifoides y se determinó la captación de 35S, el patrón de distribución de los GAG, el peso molecular y densidad de los PG y el largo de las cadenas laterales. Todos los parámetros analizados disminuyeron significativamente después de 4 y 8 días mostró una disminución de la fracción correspondiente al Congroitin-4-Sulfato. Estos resultados podrían indicar una alteración en el proceso de osificación como consecuencia de las modificaciones en las propiedades de los PG que alterarían su unión con el colágeno, molécula que desempeña un papel muy importante en el mencionado proceso