Restraining the motion of a ligand for modulating the structural phase transition in two isomorphic polar coordination polymers

A structural phase transition induced by ligand motion was found and tuned in two new polar coordination polymers, providing a new clue for modulating phase transition behaviour in known materials.

Dectin-1 gene polymorphism is associated with susceptibility to nonspecific digestive disorders and cytokine expression in rabbits

Dectin-1 plays a critical role in the pathogenesis of intestinal inflammation by recognizing the pathogenic agents and mediating cytokine responses. The objective of this study was to establish the association between dectin-1 polymorphisms and susceptibility to nonspecific digestive disorders (NSDD) and cytokine expression in rabbits. A total of 7 coding SNP were detected in dectin-1 gene. The genetic association between SNP (ss707197675A > G) and susceptibility to NSDD was evaluated using a case-control study (178 cases and 174 controls). The results revealed that the A allele was associated with an increased risk of developing NSDD in rabbits. The AA genotype significantly increased the genetic susceptibility to NSDD with odds ratio of 4.76 (95% confidence interval, 1.92-12.50, P = 0.0002) compared with GG and GA genotypes. We also experimentally induced NSDD in another independent growing rabbit population by feeding a low-fiber diet and subsequently investigated the cytokine mRNA expression. Among the 4 studied cytokines, the expression of interferon-γ, IL-17F, and IL-22 were increased 2.8 to 6.0-fold in AA genotype compared with GG genotype (P < 0.01). The greater IL-17F and IL-22 mRNA expressions indicated a positive correlation with severe intestinal inflammation (P < 0.05). The decreased expression of IL-10 was associated with severe intestinal inflammation (P = 0.006), but IL-10 expression was not influenced by dectin-1 genotype. In conclusion, polymorphism ss707197675 of dectin-1 is related with susceptibility to NSDD and increased expression of proinflammatory cytokines, and dectin-1 could be an important candidate gene associated with NSDD in rabbits.

Study on characteristics of in vitro culture and intracellular transduction of exogenous proteins in fibroblast cell line of Liaoning cashmere goat

Establishment of fibroblast cell lines of endangered goat breeds and research on the gene or protein functions based on the cells made a significant contribution to the conservation and utilization of genetic resources. In this study, a fibroblast cell line of Liaoning cashmere goat, frozen in 174 cryovials with 5 × 10(6) cells each, was successfully established from 60 goats ear marginal tissues using explant culture and cryopreservation techniques. Biological analysis of in vitro cultured cell line showed that, the cells were morphologically consistent with fibroblasts; the average viability of the cells was 94.9 % before freezing and 90.1 % after thawing; the growth process of cells was consisted of a lag phase, a logarithmic phase and a plateau phase; cell population doubling time was 65.5 h; more than 90 % of cells were diploid prior to the 6th generation; Neither microbial contamination nor cross-contamination was detected. To determine cell permeability, intracellular path and stability of exogenous proteins during the transduction, a TAT protein transduction domain was fused to the C-terminus of enhanced green fluorescent protein, the established fibroblast cell line was treated with the purified exogenous proteins at various concentrations by adding them to the cell culture media for 1-24 h and assayed cell morphology and protein presence, it was found that the purified exogenous proteins readily entered cells at a concentration of 0.1 mg/ml within 1.5 h and some of them could translocate into nucleus, moreover, the exogenous proteins appeared to be stable inside cells for up to 24 h.

Cloning and prokaryotic expression of rat homolog of Serpina3n and its expression change during liver regeneration

A strikingly upregulated expressed sequence tag was screened from regenerating rat liver at 8 h in a 0-4-8-12 h short-interval successive partial hepatectomy model from a previous study. In the present study, a full-length open reading frame (ORF) corresponding to this expressed sequence tag was predicted through electronic cloning and was subsequently cloned from an 8-h rat regenerating liver and deposited in GenBank (accession No. HM448398). Sequence analysis of HM448398 and the predicted ORF revealed that the two ORFs may be different transcripts of a gene. The sequence of HM448398 was highly homologous to that of rat Serpina3n, suggesting that it may be a homolog of Serpina3n. The pGEX-2TK prokaryotic expression vector for this ORF was constructed, and the result of sodium dodecyl sulfate polyacrylamide gel electrophoresis manifested that the recombinant expression vector could express the glutathione-S-transferase-fused rat homolog of Serpina3n in an insoluble form in BL21. The target fusion protein was purified with affinity chromatography and was used as antigen to immunize rabbits for the production of polyclonal antibodies. Immunohistochemistry and real-time reverse transcription polymerase chain reaction analysis revealed that the gene was highly expressed in the priming and termination phases of liver regeneration. These findings lay a solid foundation for further study of roles of HM448398 using knock-in and RNA interference methods during liver regeneration.

Effects of Sophy β-glucan on growth performance, carcass traits, meat composition, and immunological responses of Peking ducks

The response of Peking ducks to supplements of Sophy β-glucan was studied. A total of 160 healthy 1-d-old mixed-sex ducklings were randomly allocated to 3 groups: Sophy β-glucan (n = 80), bacitracin zinc (n = 40), and control (n = 40), which received the same antibiotics-deficient diet supplemented with 1% β-glucan, 5% bacitracin zinc, or nothing, respectively. During 2 mo of the study, growth performance, carcass composition, and meat quality of Peking ducks were evaluated. Additionally, a separate immunological study was conducted with a total of 105 healthy male Peking ducks in 7 groups (n = 15) and immunized with different doses of β-glucan (0, 0.5, 2.5, 12.5, and 62.5 μg/duck) and BSA (200 μg/duck). Blood was taken for detection of anti-BSA-IgG antibody and peripheral blood mononuclear cells proliferation assays. Groups subjected to different dietary treatments showed almost no differences in growth performance and slaughter traits except breast muscle percentage and intestinal length. These 2 indicators were significantly higher in the bacitracin zinc group than in the control and β-glucan groups (P < 0.05). Similarly, chemical compositions, fatty acids, and amino acids of breast muscle were not significantly influenced by the diet. Ducks immunized with Sophy β-glucan did not have enhanced level of anti-BSA-IgG antibodies but had significant peripheral blood mononuclear cells proliferation compared with unchallenged ducks (P < 0.01). With an increase in the glucan concentration, the proliferative responses approximately linearly increased. These findings indicate that 1% Sophy glucan did not improve duck growth performance, carcass composition, and meat quality significantly under the conditions of the present experiment and mainly had regulatory or enhancing properties on poultry nonspecific cellular immunity.

Establishment and cryopreservation of a fibroblast cell line derived from Bengal tiger (Panthera tigris tigris)

The Bengal tiger ear marginal tissue fibroblasts cell line (BTF22), containing 157 tubes of frozen cells, was successfully established by using primary explants technique and cell cryoconservation technology. Biological analysis showed that the population doubling time (PDT) for revival cells was approximately 28 h. Measurement of LDH and MDH isoenzymes showed no cross-contamination among the cells. Karyotyping showed that the frequency of cells with chromosome number 2n = 38 was 90.6-92.2%. Tests for bacteria, fungi, viruses and mycoplasma were negative. Plasmids encoding the fluorescent proteins pEGFP-N3, pEGFP-C1, pECFP-N1, pECFP-mito, pDsRed1-N1, and pEYFP-N1 were transfected into cells to study exogenous gene expression in the cells. The plasmid transfection efficiency was between 4.4% and 31.9%. Every index of the BTF22 cell line meets all the standard quality controls of American type Culture Collection (ATCC). Not only has the germline of this important Bengal tiger species been preserved at the cell level, but also valuable material had been provided for genome, postgenome and somacloning research. Moreover, the establishment of this technical platform would provide both technical and theoretical support for storing the genetic resources of other animals and poultry at the cell level.

Early embryonic blood cells collect antigens and induce immunotolerance in the hatched chicken

Earlier experimental data in our laboratory showed that introduction of an exogenous protein into early chicken embryonic blood leads to immunotolerance of hatched chicken to that protein. However, the underlying mechanism is yet unknown. In the present study, we show that the blood cells collecting circulating antigen might contribute to the establishment of immunotolerance. In this experiment, most of the chicken embryo blood cells took up injected fluorescein isothiocyanate-BSA at approximately embryonic d 3. At the same stage, 1 microL of embryo blood was taken out and incubated with BSA. After being loaded with BSA in vitro and washed, these cells were injected back into the original embryo. The BSA-specific lymphocytes were depleted in chickens whose early embryo cells had been loaded with BSA, as evidenced by a significant decrease in anti-BSA antibody after challenge with BSA when the chickens were 3 wk old. In addition, by direct injection of BSA to embryonic d 3 embryo blood, the hatched chickens had decreased amounts of anti-trinitrophenol antibody after the chickens were challenged with trinitrophenol-BSA, indicating that the helper function of BSA-specific T cells was impaired. In conclusion, these observations suggest that some early embryo blood cells possibly collect and store antigen for the establishment of self-tolerance before the maturation of B and T cells.

Stepwise regression analysis of the determinants of blood tacrolimus concentrations in Chinese patients with liver transplant

Tacrolimus (FK506) is one of the immunosuppressive drugs used effectively to prevent allograft rejection after liver transplantation. Narrow therapeutic range and individual variance in pharmacokinetics make it difficult to establish a fixed dosage for all patients. Genetic polymorphism in drug metabolizing enzymes and in transporters may influence tacrolimus exposure. A stepwise regression analysis was used to analyze the relationship between blood concentrations of tacrolimus (54 blood samples at the day of 1 week, 2 week and one month after liver transplantation) and genetic & non-genetic factors in 18 Chinese liver transplant patients. The equation of multiple stepwise regression was: Y (tacrolimus' blood concentration) = 34.534 - 0.247 (age) - 0.510 (weight) + 1.688 (dose) + 6.876 (recipient's CYP3A5 genotype) - 3.097 (donor's CYP3A5 genotype), P < 0.01. The factors impacting patient's tacrolimus blood concentrations in a descending order are weight, recipient's CYP3A5 genotype, dose, age, donor's CYP3A5 genotype. Among those, patient's weight and recipient's CYP3A5 genotype could significantly impact the blood concentration of tacrolimus. The influence of recipient's CYP3A5 gene polymorphism is much more obvious than that of donor's. Neither donor's nor recipient's MDR1 genetic polymorphisms were correlated with the blood concentration of tacrolimus.