Ku is a heterodimeric protein which is composed of Ku70 and Ku80.DNA dependent protein kinase is composed of Ku and DNA dependent protein kinase catalytic subunit (DNA-PKcs).DNA double strands break is the main method that radiation kill tumor cell,which will restraint DNA repair,and induce cell apoptosis.Ku protein is the key point in the repair of DNA.Blocking Ku protein will increase the radiosensitivity of tumor cell.

OBJECTIVE： To establish the quality standard of Tricyrtis maculata. METHODS： The character and microstructure of T. maculata were identified according to the method stated in 2015 edition of Chinese Pharmacopoeia. The contents of moisture， ash and extract were determined. TLC was used for qualitative identification of quercetin and nicotifiorin in samples. The contents of puerarin， p-hydroxybenzoic acid， nicotiflorin， ferulic acid， quercetin and kaempferol were determined by HPLC. RESULTS： The characters and microscopic identification had specificity. TLC spots of quercetin and nicotifiorin were clear and well-separated without interference from negative control. The water content， total ash content， acid insoluble ash content， alcohol soluble extract and water soluble extract for 10 batches of samples were 0.61％-1.89％，6.28％-8.88％，0.76％-1.79％，1.31％-2.00％ and 9.39％-14.27％， respectively. The linear range of puerarin， p-hydroxybenzoic acid， nicotiflorin， ferulic acid， quercetin and kaeniphenol were 0.031 92-0.111 7 μg （r＝0.999 6）， 0.085 3-0.298 5 μg （r＝0.999 5）， 0.010 76-0.037 66 μg （r＝0.999 8）， 0.070 08- 0.245 3 μg （r＝0.999 8），0.058 56-0.205 0 μg （r＝0.999 4），0.009 860-0.033 88 μg （r＝0.999 4）， respectively. The quantitation limits were 1.06， 0.47， 0.75， 1.40， 1.20， 0.74 ng， and the detection limits were 0.36， 0.12， 0.30， 0.53， 0.60， 0.31 ng， respectively. RSDs of precision， stability and repeatability tests were all less than 2％. The average recoveries were 101.54％， 102.10％， 101.46％， 103.35％， 99.36％ and 96.85％， respectively； RSDs were 1.76％， 1.68％， 1.56％， 1.26％， 0.91％ and 1.96％， respectively （n＝6）； the results of the content were 0.017-0.047， 0.042-0.140， 0.003 8-0.015 0， 0.049-0.180， 0.024- 0.091， 0.003 9-0.011 0 mg/g. CONCLUSIONS： The established quality standard can be used for the quality control of T. maculata.

β-Catenin plays a critical role in cartilage formation and development. To further understand the role of β-catenin in osteoarthritis (OA) development in temporomandibular joint (TMJ), we have generated β-catenin conditional activation mice (β-cat(ex3) ) by breeding Agc1-CreER mice with β-catenin mice. Results of histologic analysis showed the progressive TMJ defects in 3- and 6-month-old β-cat(ex3) mice (tamoxifen induction was performed at 2 weeks of age), including decreased chondrocyte numbers in the superficial layer associated with less Alcian blue staining, increased numbers of hypertrophic chondrocytes in deep layers, and rough articular surface. Compared to the TMJ phenotype of β-cat(ex3) mice, β-cat(ex3) mice showed much severe morphological defects in the superficial layer of TMJ. This may reflect that Agc1-CreER mice could efficiently target cells in the superficial layer of TMJ. Results of immunostaining showed significantly increased expression of MMP13, Col-X, Adamts4, and Adamts5 in TMJ of β-cat(ex3) mice. Results of proliferating cell nuclear antigen (PCNA), Ki67, and terminal deoxinucleotidyl transferase-mediated dUTP-fluorescein nick end labeling (TUNEL) staining further demonstrated that cell proliferation was decreased and cell apoptosis was increased in condylar cartilage of β-cat(ex3) mice. Our findings indicate that abnormal upregulation of β-catenin in TMJ leads to defects assembling to OA-like phenotype, further demonstrating that β-catenin plays a critical role in TMJ pathogenesis.
Aggrecans ; metabolism ; Animals ; Apoptosis ; Cartilage, Articular ; metabolism ; Cell Differentiation ; Cell Proliferation ; Cells, Cultured ; Disease Models, Animal ; In Situ Nick-End Labeling ; Mice ; Osteoarthritis ; metabolism ; Phenotype ; Signal Transduction ; Surface Properties ; Temporomandibular Joint ; metabolism ; beta Catenin ; metabolism