IntroductionThe aim of this study was to evaluate, for the first time, the differences in gene expression profiles of normal and osteoarthritic (OA) subchondral bone in human subjects.MethodsFollowing histological assessment of the integrity of overlying cartilage and the severity of bone abnormality by micro-computed tomography, we isolated total RNA from regions of interest from human OA (n = 20) and non-OA (n = 5) knee lateral tibial (LT) and medial tibial (MT) plateaus. A whole-genome profiling study was performed on an Agilent microarray platform and analyzed using Agilent GeneSpring GX11.5. Confirmatory quantitative reverse-transcription polymerase chain reaction (qRT-PCR) analysis was performed on samples from 9 OA individuals to confirm differential expression of 85 genes identified by microarray. Ingenuity Pathway Analysis (IPA) was used to investigate canonical pathways and immunohistochemical staining was performed to validate protein expression levels in samples.ResultsA total of 972 differentially expressed genes were identified (fold change ≥ ± 2, P ≤0.05) between LT (minimal degeneration) and MT (significant degeneration) regions from OA samples; these data implicated 279 canonical pathways in IPA. The qRT-PCR data strongly confirmed the accuracy of microarray results (R2 = 0.58, P <0.0001). Novel pathways were identified in this study including Periostin (POSTN) and Leptin (LEP), which are implicated in bone remodeling by osteoblasts.ConclusionsTo the best of our knowledge, this study represents the most comprehensive direct assessment to date of gene expression profiling in OA subchondral bone. This study provides insights that could contribute to the development of new biomarkers and therapeutic strategies for OA.

Objective To evaluate the interaction of articular cartilage (AC) and subchondral bone (SB) through analysis of osteoarthritis (OA)-related genes of site-matched tissue. Design We developed a novel method for isolating site-matched overlying AC and underlying SB from three and four regions of interest respectively from the human knee tibial plateau (n=50). For each site, the severity of cartilage changes of OA were assessed histologically, and the severity of bone abnormalities were assessed by microcomputed tomography. An RNA isolation procedure was optimized that yielded high quality RNA from site-matched AC and SB tibial regions. Q-PCR analysis was performed to evaluate gene expression of 61 OA-associated genes for correlation with cartilage integrity and bone structure parameters. Results A total of 27 (44%) genes were coordinately up or down regulated in both tissues. The expression levels of 19 genes were statistically significantly correlated with the severity of AC degeneration and changes of SB structure; these included: ADAMTS1, ASPN, BMP6, BMPER, CCL2, CCL8, COL5A1, COL6A3, COL7A1, COL16A1, FRZB, GDF10, MMP3, OGN, OMD, POSTN, PTGES, TNFSF11 and WNT1. Conclusions These results provide a strategy for identifying targets whose modification may have the potential to ameliorate pathological alterations and progression of disease in both AC and SB simultaneously. In addition, this is the first study, to our knowledge, to overcome the major difficulties related to isolation of high quality RNA from site-matched joint tissues. We expect this method to facilitate advances in our understanding of the coordinated molecular responses of the whole joint organ.

Research has found that many people view climate change as a psychologically distant, future threat, which leads them to be less motivated to engage in pro-environmental behavior. Engaging in episodic future thinking (EFT; projecting the self into the future to pre-experience future events) may facilitate the perception of future events as psychologically close, thereby increasing the perceived risk associated with those events. Therefore, engagement in EFT regarding climate change–related risks should induce higher risk perceptions and lead to acting pro-environmentally. In two experiments, we demonstrated that engaging in EFT to pre-experience climate change–related risk events was associated with a higher level of risk perception and a greater tendency toward pro-environmental behavior, including energy-saving use of air-conditioning (Experiment 1), willingness to participate in beach cleaning (Experiment 2), and choice of a meal with lower environmental impact (Experiment 2). The current research provides experimental evidence for an innovative approach to improving public engagement with climate change.

Objective To identify disease relevant genes and pathways associated with knee Osteoarthritis (OA) progression in human subjects using medial and lateral compartment dominant OA knee tissue. Design Gene expression of knee cartilage was comprehensively assessed for three regions of interest from human medial dominant OA (n=10) and non-OA (n=6) specimens. Histology and gene expression were compared for the regions with minimal degeneration, moderate degeneration and significant degeneration. Agilent whole-genome microarray was performed and data were analyzed using Agilent GeneSpring GX11.5. Significant differentially regulated genes were further investigated by Ingenuity Pathway Analysis (IPA) to identify functional categories. To confirm their association with disease severity as opposed to site within the knee, 30 differentially expressed genes, identified by microarray, were analyzed by quantitative reverse-transcription polymerase chain reaction on additional medial (n=16) and lateral (n=10) compartment dominant knee OA samples. Results A total of 767 genes were differentially expressed ≥two-fold (P ≤0.05) in lesion compared to relatively intact regions. Analysis of these data by IPA predicted biological functions related to an imbalance of anabolism and catabolism of cartilage matrix components. Up-regulated expression of IL11, POSTN, TNFAIP6, and down-regulated expression of CHRDL2, MATN4, SPOCK3, VIT, PDE3B were significantly associated with OA progression and validated in both medial and lateral compartment dominant OA samples. Conclusions Our study provides a strategy for identifying targets whose modification may have the potential to ameliorate pathological alternations and progression of disease in cartilage and to serve as biomarkers for identifying individuals susceptible to progression.

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In recent years, L-ascorbic acid (L-AA), or vitamin C, has been attracting attention as a potential anticancer drug that mediates hydrogen peroxide-induced oxidation and ten-eleven translocation 2-catalyzed DNA demethylation. However, the precise mechanism by which L-AA acts remains unclear. We examined the cytotoxic effects of L-AA or sodium ascorbate in human cervical carcinoma cells by assessing cell viability, expression of cell cycle-related mRNAs and proteins, and mitochondrial functions, and by performing flow cytometric analyses of cell cycle profiles, apoptosis, cell proliferation, and production of reactive oxygen species (ROS). We later tested the effects of ascorbates in combination with two first-line chemotherapeutic drugs, cisplatin, and doxorubicin. At pharmacological concentrations (1-10 mM), L-AA increased ROS levels; decreased levels of several cell cycle-related proteins, including p53, p21, cyclin D1, and phosphorylated histone 3 at serine residue 10; induced DNA damage, as indicated by changes in γH2A.x; decreased levels of the anti-oxidative transcription factor Nrf2; and increased levels of catalase, superoxide dismutase 1, and endoplasmic reticulum stress-related indicators, such as the p-eIF2α/eIF2α ratio and CHOP levels. L-AA also promoted cell proliferation and induced apoptosis and mitochondrial dysfunction. Finally, L-AA increased the susceptibility of HeLa cells to cisplatin and doxorubicin. These findings provide insight into how the adjustment of the cellular ROS status through L-ascorbate (L-AA or sodium ascorbate) administration could potentially synergistically enhance the efficacy of cancer therapies.

Knee osteoarthritis (OA) is a common degenerative articular disorder and considered one of the primary causes of pain and functional disability. Knee OA is prevalent in 10% of men and 13% of women aged 60 years above. The study aims to use cartilage tissue engineering that combines the triads of decellularized porcine cartilage graft as “scaffold,” plasma rich platelet (PRP) as “signal” and chondrocytes from rat as “cell” to attenuate ACLT‐induced OA progression and regenerate the knee cartilage in rats. Decellularization of the porcine cartilage was characterized by hematoxylin and eosin, 4,6‐Diamidino‐2‐phenylindole staining, scanning electron microscopy and residual DNA quantification. The protective effect of decellularized porcine cartilage graft (dPCG) was evaluated by intra‐articular administration in surgically induced anterior cruciate ligament transection (ACLT) rat osteoarthritis (OA) model. Supercritical carbon dioxide technology completely decellularized the porcine cartilage. Intra‐articular administration of dPCG with or without PRP significantly reduced the ACLT‐induced OA symptoms and attenuated the OA progression. Pain‐relief by dPCG with or without PRP was assessed by capacitance meter and improved articular cartilage damage in the rat knee was characterized by X‐ray and micro‐CT. Besides, the histological analysis depicted cartilage protection by dPCG with or without PRP. The repairation and attenuation effect by dPCG with or without PRP in the articular knee cartilage damage were also explored by safranin‐O, type II collagen, aggrecan and SOX‐9 immuno‐staining. To conclude, intra‐articular administration of dPCG with or without PRP is efficient in repairing the damaged cartilage in the experimental OA model.

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