Transient expression is the major method to express foot-and-mouth disease virus (FMDV) capsid proteins in mammalian cells. To achieve stable expression of FMDV capsid proteins and efficient assembly of virus like particles (VLPs) in cells, the plasmids of piggyBac (PB) transposon-constitutive expression and PB transposon-tetracycline (Tet) inducible expression vectors were constructed. The function of the plasmids was tested by fluorescent proteins. By adding antibiotics, the constitutive cell pools (C-WT, C-L127P) expressing P12A3C (WT/L127P) genes and the inducible cell pools (I-WT, I-L127P) expressing P12A3C (WT/L127P) genes were generated. The genes of green fluorescent protein, 3C protease and reverse tetracycline transactivator (rtTA) were integrated into chromosome, which was confirmed by fluorescence observation and PCR testing. The cell pool I-L127P has a stronger production capacity of capsid proteins and VLPs, which was confirmed by Western blotting and enzyme linked immunosorbent assay (ELISA), respectively. In conclusion, inducing the chromosomal expression of FMDV capsid proteins was firstly reported, which may facilitate the technical process of mammalian production of FMDV VLPs vaccine and the construction of mammalian inducible expression systems for other proteins.
Animals ; Foot-and-Mouth Disease Virus/genetics* ; Capsid Proteins ; Viral Proteins/metabolism* ; Foot-and-Mouth Disease/prevention & control* ; Tetracyclines/metabolism* ; Viral Vaccines ; Antibodies, Viral ; Mammals/metabolism*

We adopted firstly the dextran-coated charcoal(DCC) and SP methods to detect estrogen receptor (ER) expression of bone tissue in ovariectomized(OVX) rats. The results demonstrate that in OVX rats, XW630 can significantly promote ER expression in bone tissue and increase the ER content. XW630 is superior to estrone in effectiveness. The results also reveal that the ER expression in OVX rat bone tissue decreases with the lapse of time, indicating that the expression of ER depends on the existence of estrogen.
Animals ; Bone and Bones ; metabolism ; Estrogens, Conjugated (USP) ; pharmacology ; Female ; Ovariectomy ; Piperazines ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Receptors, Estrogen ; biosynthesis ; Tetracycline ; pharmacology ; Tetracyclines

This study was performed to investigate the mechanism of an anti-osteoporosis new drug XW630 for promoting the osteogenic action. Osteoblast clone was cultivated from SD adult rat calvaria in vitro, the estrogen receptor messenger RNA(ERmRNA) expression in the osteoblasts of rats was detected directly with high-sensitive RT-PCR firstly. The results indicated that XW630 can significantly promote ERmRNA expression in osteoblasts in the time-dependent manner. Being superior to other two kinds of estrogen in the same concentration (10(-6) mol/L), XW630 probably plays an important role in the bone pathogenesis by means of ER gene regulatory functions.
Animals ; Cells, Cultured ; Female ; Gene Expression ; Osteoblasts ; drug effects ; metabolism ; Piperazines ; pharmacology ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, Estrogen ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Tetracycline ; pharmacology ; Tetracyclines

AIMTo study the effect of XW630 on expression of pro-oncogene c-myc in the long bones of fetal mice in vitro for postulating the mechanism by which XW630 exerts its effect on bone.

METHODSThe fetuses of pregnant mice were removed on day 16 of gestation, the long bones of the forelimbs of female fetal mice were freed of muscle and soft tissue and cultured in a specific device for 48 h in BGJb medium treated with 1 x 10(-7), 1 x 10(-8) and 1 x 10(-9) mol.L-1 XW630 in the final medium. After cultured for 48 h, the long bones were harvested and immunohistochemical analysis was performed for determination of c-Myc protein expression in epiphyseal plates. The areas of positive cells in the resting zone, proliferative zone and hypertrophic zone in epiphyseal plate were determined under image analytic system.

RESULTSWhen the concentration of XW630 in the medium was 1 x 10(-9) mol.L-1, the area of c-Myc positive cells increased in the proliferative zone compared with 1 x 10(-9) mol.L-1 in the estrone group, significant increase was also observed in the resting zone compared with the control group. When the concentration of XW630 in medium was 1 x 10(-8) or 1 x 10(-7) mol.L-1, stronger expression than that in the control group and the estrone group at the same concentration was observed in each of the three zones.

CONCLUSIONThe estrogenic effect of XW630 on bone was stronger than that of estrone. XW630 may promote proliferation and differentiation of chondroncytes by promoting c-Myc protein expression in chondroncytes. Thus, endochondral bone formation was enhanced.

Animals ; Chondrocytes ; metabolism ; Culture Techniques ; Estrone ; pharmacology ; Female ; Fetus ; Mice ; Piperazines ; pharmacology ; Pregnancy ; Proto-Oncogene Proteins c-myc ; metabolism ; Tetracyclines ; pharmacology ; Ulna ; drug effects ; metabolism ; Up-Regulation ; drug effects

BACKGROUNDTetracycline (TET) has been found to have both antibiotic and anti-inflammatory properties. The anti-inflammatory effect of topical TET on atopic dermatitis (AD) has not been reported. The purpose of this study was to explore the potential role of topical TET and its anti-inflammatory effects in a mouse model of AD.

METHODSThe 2% TET was applied topically to ears of MC903-induced AD-like BALB/c mice once a day. AD-like symptoms and severity were evaluated by assessing skin scoring of dermatitis, ear thickness, and frequency of scratching. Serum IgE and thymic stromal lymphopoietin (TSLP) levels were measured by enzyme-linked immunosorbent assay. Western blot was used for analyzing the expressions of TSLP, protease-activated receptor 2 (PAR2), and nuclear factor-kappa B (NF-κB) in skin lesions. Real-time polymerase chain reaction was performed to assess the mRNA levels of TSLP and inflammatory cytokines including interleukin (IL)-4, IL-13, tumor necrosis factor (TNF)-α, and IL-1β in skin lesions.

RESULTSScoring of dermatitis (9.00 ± 0.63 vs. 6.67 ± 1.03, P = 0.001), ear thickness (0.44 ± 0.02 mm vs. 0.40 ± 0.03 mm, P = 0.018), and serum IgE level (421.06 ± 212.13 pg/ml vs. 244.15 ± 121.39 pg/ml, P = 0.047) were all improved in the 2% TET treatment group compared with AD group. Topical TET significantly reduced the serum level of TSLP (119.04 ± 38.92 pg/ml vs. 65.95 ± 54.61 pg/ml, P = 0.011) and both mRNA and protein expressions of TSLP in skin lesions compared with AD group (P = 0.003 and 0.011, respectively), and NF-κB and PAR2 expression in skin lesions were also suppressed (P = 0.016 and 0.040, respectively). Furthermore, expressions of inflammatory cytokines IL-4, IL-13, and TNF-α in skin lesions were down-regulated in 2% TET group compared with AD group (P = 0.035, 0.008, and 0.044, respectively).

CONCLUSIONSTopical TET exerted anti-inflammatory effects through suppression of TSLP and inflammatory cytokines in AD mouse model, suggesting TET as a potential agent for the topical treatment of AD in the future.

Administration, Topical ; Animals ; Calcitriol ; analogs & derivatives ; toxicity ; Cytokines ; Dermatitis, Atopic ; chemically induced ; drug therapy ; Disease Models, Animal ; Enzyme-Linked Immunosorbent Assay ; Female ; Interleukin-13 ; metabolism ; Interleukin-4 ; metabolism ; Mice ; Mice, Inbred BALB C ; Tetracyclines ; administration & dosage ; therapeutic use ; Tumor Necrosis Factor-alpha ; metabolism