Overexpression of P-glycoprotein on fibroblast-like synoviocytes in refractory rheumatoid arthritis patients: a potential mechanism for multidrug resistance in rheumatoid arthritis treatment.

This study aims to investigate the role of P-glycoprotein (P-gp) expression level in drug resistance to disease-modifying anti-rheumatic drugs in refractory rheumatoid arthritis (RRA). We evaluated and compared the expression levels of P-gp in fibroblast-like synoviocyte (FLS) cells in patients with rheumatoid arthritis (RA) and osteoarthritis (OA), and investigated the potential mechanism of P-gp-induced multidrug resistance in RRA. Ten patients were enrolled and divided into two groups: six in the RA group and four in the OA group. The expression level of P-gp in FLS cells was detected by western blotting following cell culture. A linear correlation algorithm was used to assess the association between the level of P-gp and disease activity  (using DAS28 scoring), as well as the duration of methotrexate (MTX) treatment in the RRA patients. The level of P-gp in the RRA patients was markedly higher than that in the OA patients (P < 0.05, t = -4.179). There was a positive linear correlation between the P-gp level in FLS cells and the duration of MTX treatment in the RRA group (Г = 0.733, P < 0.05), whereas there was no significant correlation between the P-gp level and DAS28 scoring (Г = 0.206, P > 0.05). P-gp might be upregulated during the progression of RRA, which possibly correlates with the development of resistance to MTX.

Genetic analysis of floral organ size in broccoli × cabbage via a mixed inheritance model of a major gene plus polygene.

Broccoli and cabbage are important vegetable crops that produce hybrid seeds after insect pollination; the size of floral organs is crucial for this process. To investigate the genetic characteristics of floral organ sizes (corolla width, petal length and width, and lengths of stamen, anther, style, and stigma) and to improve the flower size and breeding efficiency of broccoli, we used multi-generation analysis of a major gene plus polygene model. Six populations obtained from a broccoli inbred line 93219 (small floral organs) and cabbage inbred line 195 (large floral organs) were used for the analysis. Corolla and petal width and stamen and anther length were controlled by the additive-dominance-epistasis polygene model. The heritability of these traits in BC1, BC2, and F2 generations was high (72.80-93.76%). Petal and stigma length were governed by the two major genes of additive-dominance-epistasis effects plus additive-dominance polygene model; the major gene heritability in the F2 generation were 79.17 and 65.77%, respectively. Style length was controlled by one major gene of additive-dominance effects plus additive-dominance-epistasis polygene model; the major gene heritability in BC1, BC2, and F2 were 40.60, 10.35, and 38.44%, respectively; the polygene heritability varied from 41.85 to 68.44%. Our results provide important genetic information for breeding, which could guide improvement of flower-related traits and lay the foundation for quantitative trait loci mapping of the flower-size traits in Brassica.

Biological correlation between glucose transporters, Ki-67 and 2-deoxy-2-[18F]-fluoro-D-glucose uptake in diffuse large B-cell lymphoma and natural killer/T-cell lymphoma.

The purpose of this study was to investigate the association between cellular 2-deoxy-2-[18F]-fluoro-D-glucose ((18)F-FDG) uptake and the expression of several subtypes of glucose transporters (GLUT) and Ki-67 in diffuse large B-cell lymphoma (DLBCL) and natural killer (NK)/T-cell lymphoma (NKTCL). Cell lines were histologically determined to be DLBCL (Raji cells) and NKTCL (Daudi cells), and uptake after pretreatment with (18)F-FDG was determined. Real-time polymerase chain reaction was performed to detect the expression levels of GLUTs 1, 2, 3, 4, and 7 and Ki-67, and to evaluate their association with (18)F-FDG uptake in DLBCL and NKTCL cells. The uptake rates of (18)F-FDG ranged from 18 to 46% (average 30 ± 10.20%) in Raji cells and 25 to 48% (average 35.6 ± 7.57%) in Daudi cells. In DLBCL cells, the expression levels of GLUTs 1, 3, and 7 were significantly correlated with cellular (18)F-FDG uptake rates (Spearman's rank correlation coefficient of 0.667, 0.516, and 0.468, respectively; P < 0.05). In NKTCL cells, the expression levels of GLUTs 1 and 3 were observed to be significantly correlated with cellular (18)F-FDG uptake rates (Spearman's rho of 0.756 and 0.498, respectively; P < 0.05). Ki-67 played no role in (18)F-FDG uptake in Raji or Daudi cells. In conclusion, the data acquired through this preliminary study indicate that GLUT 1 and GLUT 3 contribute to 18F-FDG uptake in DLBCL and NKTCL.

Molecular characterization and phylogenetic analysis of porcine epidemic diarrhea virus samples obtained from farms in Gansu, China.

Porcine epidemic diarrhea poses significant sanitation problems in the porcine industry, and has negatively affected the economy in recent years. In this study, 48 fecal specimens were collected from piglets from four intensive swine farms located in the Gansu Province of China. The molecular diversity and phylogenetic relationships between porcine epidemic diarrhea viruses (PEDV) prevalent in Gansu were probed, and the resultant proteins were characterized. Sequence analysis of the spike protein (S) genes showed that each specimen had unique characteristics, and that the PEDV1/S/4 strain could be differentiated from the others via a unique mutation of the S gene. The phylogeny of S glycoprotein showed that all strains were clustered into two major groups. The four Gansu PEDV field strains were characterized into different groups; this finding was consistent with the results of the protein characterization prediction. This analysis additionally revealed the unique characteristics of each specimen. The results of this study could be used to elucidate the prevalence of PEDV and contribute to the prevention of PEDV in Gansu.

Comparative proteomic changes of differentially expressed whey proteins in clinical mastitis and healthy yak cows.

Under the traditional grazing system on the Qinghai-Tibetan Plateau, the amount of milk in domesticated yak (Bos grunniens) with clinical mastitis decreases and the milk composition is altered. To understand the mechanisms of mammary gland secreted milk and disease infection, changes in the protein composition of milk during clinical mastitis were investigated using a proteomic approach. Milk whey from yak with clinical mastitis was compared to whey from healthy animals with two-dimensional gel electrophoresis using a mass spectrometer. Thirteen protein spots were identified to be four differentially expressed proteins. Increases in the concentrations of proteins of blood serum origin, including lactoferrin, were identified in mastitic whey compared to normal whey, while concentrations of the major whey proteins, casocidin-I, a-lactalbumin, and b-lactoglobulin, were downregulated in mastitic whey. These results indicated significant differences in protein expression between healthy yaks and those with clinical mastitis, and they may provide valuable information for finding new regulation markers and potential protein targets for the treatment of mastitis.

Single-nucleotide polymorphism of the pri-miR-34b/c gene is not associated with susceptibility to congenital heart disease in the Han Chinese population.

Recent evidence has shown that the microRNA polymorphism may play an important role in the susceptibility to congenital heart disease (CHD). A potentially functional SNP rs4938723 (T>C) in the promoter region of pri-miR-34b/c might affect transcription factor GATA binding and therefore pri-miR-34b/c expression. We genotyped the pri-miR-34b/c polymorphism in a case-control study of 590 patients and 672 controls in a Han Chinese population and assessed the effects of the pri-miR-34b/c polymorphism on CHD susceptibility by TaqMan SNP genotyping assay. There was no association between the pri-miR-34b/c polymorphism and the risk of CHD in both genotype and allelic frequency. In a subsequent analysis of the association between this polymorphism and CHD classification, there was still no significant difference in both genotype and allelic frequency. Our results suggest that the pri-miR-34b/c polymorphism rs4938723 is not associated with susceptibility to sporadic CHD in the Han Chinese population.

Involvement of ERK1/2 signaling in proliferation of eight liver cell types during hepatic regeneration in rats.

It has been well established that ERK1/2 signaling, often subdivided into nine types of pathways, can regulate the hepatocyte proliferative response during liver regeneration. However, the effect of ERK1/2 signaling on the proliferation of other hepatic cell types remains unclear. We isolated and purified 8 liver cell types at 10 time points after 2/3 hepatectomy in adult rats. For each cell type, mRNA expression changes for ERK1/2 signaling-involved genes were monitored up to 168 h, using microarrays. Real-time PCR assays were performed for array data verification. The expression levels of these genes varied considerably between different cell types. Integrating microarray results with gene synergical analysis, at the priming phase, activation of integrin/Grb2/Ras pathway in hepatocytes apparently contributed to G0/G1 transition. Two other pathways, G-protein/EPAC/Rap1 and G-protein/PKA/Rap1, were stimulated in hepatic stellate cells, while RTK/PKC/Ras and RTK/Grb2/Ras were stimulated in Kupffer cells. At the progressive phase, the ERK1/2 pathway is involved in hepatocyte replication; three pathways, namely Ca(2+)/PKC/Ras, RTK/Grb2/Ras and G-protein/EPAC/Rap1, were found to play roles in biliary epithelial cell proliferation, while RTK/PKC/Ras and RTK/Grb2/Ras were involved in Kupffer cell proliferation, and G-protein/PKC/Ras in pit cell proliferation. At the terminal phase, the promotive effect of the ERK1/2 pathway on replication of hepatocytes, biliary epithelial cells, oval cells, hepatic stellate cells, Kupffer cells, and dendritic cells was considerably reduced, possibly due to their differentiation at the end of regeneration. G-protein/PKC/Ras, integrin/Grb2/Ras and G-protein/ PKA/Rap1 pathways were active in sinusoidal endothelial cells, perhaps to aid in their proliferation. We conclude that ERK1/2 has a signaling role in the regulation of proliferation of 8 cell types during liver regeneration process.