-
[show abstract]
[hide abstract]
ABSTRACT: Macrophage recruitment to sites of inflammation is an essential step in host defense. However, the signals regulating the mobilization of these cells are still not fully understood. Sphingosine-1-phosphate (S1P), a pleiotropic bioactive lipid mediator, is known to regulate an array of biological activities in various cell types. Here, we investigated the roles of S1P and S1P receptors (S1PRs) in macrophage migration in vitro. Furthermore, we explored the cross-talk between transforming growth factor-β1 (TGF-β1) and S1P signalling pathways in this process. We found that S1P exerted a powerful migratory action on RAW264.7 macrophages, as determined in Boyden chambers. Moreover, by employing RNA interference technology and pharmacological tools, we have demonstrated that S1PR1, but not S1PR2 and S1PR3, is required for S1P-induced macrophage migration. Importantly, we observed a pronounced increase in sphingosine kinase-1 (SphK1) mRNA expression and subsequently increase in S1P production, following transforming growth factor-β1 (TGF-β1) stimulation in RAW264.7 macrophages. The expression of S1PR1, but not S1PR2 and S1PR3, was also significantly up-regulated after TGF-β1 stimulation. Interestingly, exogenously added S1P-induced up-regulation of SphK1 and the synthesis of additional S1P, suggesting a self-amplifying loop of S1P to enhance macrophage migration. In conclusion, our results reveal that SphK1/S1PR1 signalling axis is induced by TGF-β1 and stimulates cell migration in RAW 264.7 macrophages. This study provides new clues for the molecular mechanisms of macrophage recruitment during inflammation.
Biochemical and Biophysical Research Communications 08/2012; 426(3):415-20. · 2.48 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A population of 117 doubled haploid (DH) lines derived from the cross of Zhaiyeqing 8 (indica)× Jingxi 17 (japonica) was employed to map quantitative trait loci (QTL) underlying four physiological traits related to chlorophyll contents of
the flag leaf. There were significantly positive correlations among chlorophyll a, chlorophyll b and chlorophyll a + b content.
Chlorophyll a/b ratio was significantly negatively correlated with chlorophyll b content. These four traits were normally
distributed with transgressive segregation, suggesting that they were controlled by multiple minor genes. A total of 11 QTLs
were detected for the four traits and they lay on six chromosomes. Each of them explained 9.2%–19.6% of the phenotypic variations,
respectively. Of these, two QTLs controlling chlorophyll a content were mapped on chromosomes 2 and 5; four QTLs underlying
chlorophyll b content were mapped on chromosomes 2, 3, 5 and 9; three QTLs underlying chlorophyll a + b amount were mapped
on chromosomes 3, 5 and 9; two QTLs underlying chlorophyll a/b ratio were mapped on chromosomes 6 and 11. The intrinsic relationship
among the four traits and the practical implication in rice breeding are discussed.
Frontiers of Biology in China 04/2012; 3(4):443-448.
-
[show abstract]
[hide abstract]
ABSTRACT: Previous researches showed that the expression level of E-Cad in most infiltrating cancer cells was reduced or negative. This study explored whether 4HPR restrained the infiltration of bladder cancer cells through regulating the expression of E-Cad. The infiltrating bladder cancer cells T24 were cultured, and then treated by a proper dosage of drug. Their viability was a determined by MTT method. Western blotting and RT-PCR were adopted to detect the changes of E-Cad gene expression at both protein and mRNA levels. Moreover, immunofluorescent staining and confocal fluorescence microscopy were employed for the observation of the expression of E-Cad. The result showed that, at both mRNA and protein levels, the expression level of E-Cad in T24 cells treated by 4HPR was significantly higher than that of control group, while the β-Cat expression was also relocated from the cell nucleus to cytoplasm. Our findings suggested that the regulatory function of 4HPR on infiltration of bladder cancer cells T24 is at least partly achieved by regulating the expression of E-Cad.
Journal of Huazhong University of Science and Technology 04/2012; 32(2):237-41. · 0.38 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Congenital cataract is a highly heterogeneous disorder at both the genetic and the clinical-phenotypic levels. A unique cataract was observed in a 4-generation Chinese family, which was characterized by autosomal dominant inheritance and late-onset. Mutations in the 13 known genes (CRYAA, CRYAB, CRYBB1, CRYBB2, CRYGC, CRYBA1/A3, CRYGD, Connexin50, Connexin46, intrinsic membrane protein LIM2, cytoskeletal protein BFSP2, the major intrinsic protein-MIP and the heat shock factor HSF4) have previously been demonstrated to be the frequent reason for isolated congenital cataracts, but the exact molecular basis and underlying mechanisms of congenital cataract still remain unclear. This study was designed to find whether these 13 genes developed any mutation in the family members and to identify the disease-causing gene. Polymerase chain reaction (PCR) and direct DNA sequence analysis were carried out to detect the 13 genes. The results showed that no mutation causing amino acid alternations was found in these potential candidate genes among all patients in the family, and only several single-nucleotide polymorphisms (SNPs) were identified. A transitional mutation in the fourth intron of CRYBB2 and some silent mutations in the first exon of BFSP2 and CRYGD were found in the cataract family, but further study showed that these mutations could also be found in normal controls. It was concluded that some unidentified genes may underlie the occurrence of late-onset cataract in this family. A genome-wide screening will be carried out in the next study.
Journal of Huazhong University of Science and Technology 12/2010; 30(6):792-7. · 0.38 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The action mechanism of matrix metalloproteinases-2 (MMP-2) and tissue inhibitor of metalloproteinases-2 (TIMP-2) in the genesis, development and degeneration of haemangioma was investigated by detecting their expression in the tissue of haemangioma in different phases by using the immunohistochemistry. Fifty paraffin-embedded specimens of skin capillary haemangioma were collected, which were documented in the Department of Pathology, Renmin Hospital of Wuhan University from 2000 to 2006. All samples were stained by regular HE method, and proliferative cell nuclear antigen (PCNA) was tested by immunohistochemical S-P method. The samples were classified according to the Mulliken criteria and the expression pattern of PCNA. Immunohistochemical S-P method was applied to detect the expression of MMP-2 and TIMP-2 in proliferative and degenerative phases of cutaneous capillary haemangioma, and in normal skin tissues. In combination with the detection of the expression of factor VIII-related antigen, it was verified that in haemangioma tissues, the cells expressing MMP-2 and TIMP-2 were vascular endothelial cells. The MMP-2 and TIMP-2 expression was quantitatively analyzed by image analysis system (HPIAS-1000), and one-way ANOVA(107) and SNK(q) test were done to analyze average absorbance (A) and positive area rate of immunohistochemically positive particles by using SPSS11.5. The results showed: (1) Among 50 samples of haemangioma, there were 26 proliferative haemangiomas, and 24 degenerative haemangiomas, respectively; (2) The expression of MMP-2 was weak in normal vascular endothelial cells, cytoplasm of connective tissues and extracellular matrix around blood vessels. The expression of MMP-2 in proliferative group was significantly higher than in degenerative group and control group (normal skin) (P<0.05), but there was no statistically significant difference between the latter two groups; (3) TIMP-2 was highly expressed in normal tissues, degenerative vascular endothelial cells, cytoplasm of connective tissues and extracellular matrix around blood vessels. The expression level of TIMP-2 in proliferative phase was significantly lower than in degenerative phase (P<0.05), and the expression of TIMP-2 in proliferative phase was significantly different from that in degenerative phase and normal tissues (P<0.05). It was concluded that in proliferative phase of haemangioma, MMP-2 may promote over-proliferation of endothelial cells of haemangioma, and in degenerative phase, TIMP-2 can inhibit the proliferation of endothelial cells of haemangioma. The two substances play important roles in the genesis, development and degeneration of haemangiomas.
Journal of Huazhong University of Science and Technology 10/2009; 29(5):614-9. · 0.38 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The electrophoretic mobility shift assay is a useful tool to identify proteins and nucleic acids interactions. Traditionally, the nucleic acids fragments are end-labeled with (32)P. We present here the use of fluorescent methodologies for studies of RNA in place of radioactivity. The method is highly sensitive and quantitative with the use of an infrared fluorescence imaging system. Fluorescently labeled primers can be used to monitor protein-RNA interactions by fluorescent mobility shift assays. The simplicity and validity of this approach may have more advantages than that of previous methods that traditionally used hazardous radioisotopes. This method was successfully tested in the study of the interactions between MS2 Coat Protein and its RNA target.
Molecular Biology Reports 09/2009; 37(6):2871-5. · 2.93 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Plant height and tiller number are two important characters related to yield in rice (Oriza sativa L.). Zhenshan97 x Minghui63 recombinant inbred lines were employed to dissect the genetic basis of development of plant height and tiller number using conditional and unconditional composite interval mapping approaches. The traits were normally distributed with transgressive segregation in both directions. Increasingly negative correlations were observed between tiller number and plant height at five consecutive growth stages. A total of 23 and 24 QTL were identified for tiller number and plant height, respectively. More QTL were detected by conditional mapping than by conventional mapping. Different QTL/genes apparently controlled the traits at different developmental stages. Three genomic regions were identified as putative co-located QTL, which showed opposite additive effects on tiller number and plant height. Furthermore, in the period reaching maximum tiller number, the expression of QTL for tiller number was active, whereas that of QTL for plant height was inactive. These facts provided a possible genetic explanation for the negative correlations between the traits. The research demonstrates conditional mapping to be superior to conventional mapping for this type of research. Implications of the results for hybrid rice improvement are discussed.
Hereditas 01/2007; 143(2006):236-45. · 0.79 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Rice (Oryza sativa) is one of the most important cereal plants in the world. Wild-abortive (WA) and Honglian (HL) cytoplasmic male sterility (CMS) have been used extensively in the production of hybrid seeds. Although a variable number of fertility-restorer genes (Rf) for WA and HL-CMS have been identified in various cultivars, information on Rf in Oryza species with the AA-genome is sparse. Therefore the distribution and heredity of Rf for WA and HL-CMS in wild rice species of Oryza with the AA-genome were investigated.
Fertility-restorer genes for WA and HL-CMS in wild rice species with the AA-genome were investigated by following the fertility of microspores identified by I2-KI staining and by following the seed-setting rate of spikelets. A genetic model of Rf in some selected restorer accessions was analysed based on the fertility segregation of BC1F1 populations.
Fertility analysis showed that 21 out of 35 HL-type F1s, and 13 out of 31 WA-type F1s were scored as fertile. The frequency of Rf in wild rice was 60% for HL-CMS and 41.9% for WA-CMS, respectively. The fertility-restorer accessions, especially those with complete restoring ability, aggregated mainly in two species of O. rufipogon and O. nivara. The wild rice accessions with Rf for HL-CMS were distributed in Asia, Oceania, Latin American and Africa, but were centered mainly in Asia, whilst the wild restorer accessions for WA-CMS were limited only to Asia and Africa. Apart from one restorer accession that possessed two pairs of Rf for WA-CMS, all of the other nine tested wild restorer accessions each contained only a single Rf for WA-CMS or HL-CMS. Allele analysis indicated that there existed at least three Rf loci for the WA and HL-CMS systems.
These data support the hypothesis that fertility-restorer genes exist widely in Oryza species with the AA-genome, and that Rf in Oryza sativa originated from the Oryza rufipogon/Oryza nivara complex, the ancestor of cultivated rice in Asia. The origin and evolution of Rf is tightly linked to that of CMS in wild rice, and fertility of a given CMS type is controlled by several Rf alleles in various wild restorer accessions.
Annals of Botany 10/2005; 96(3):461-6. · 4.03 Impact Factor
