The complete chloroplast genome of Polygala subopposita, an endemic milkwort in China.

Polygala subopposita is an endemic milkwort species in China. In this study, we present the assembly of its chloroplast genome (plastome) for the first time. The total plastome size is 164,784 bp in length, consisting of a large single-copy (LSC) region of 83,235 bp, a small single-copy (SSC) region of 8,037 bp, and two inverted repeat (IR) regions of 36,756 bp that have expanded approximately 10 kb into the SSC region. A total of 111 unique genes were identified in the plastome, including 77 protein-coding, 30 tRNA, and four rRNA genes. Interestingly, the trnQUUG gene was found to have two additional copies in the IRs, and the clpP gene lost its entire intron 2. Phylogenetic analysis suggests a close relationship between P. subopposita and P. crotalarioides. These findings provide valuable genomic resources for further research on the phylogenetic and evolutionary studies of Polygalaceae.

The complete chloroplast genome of Ormosia nuda (fabaceae), an endemic species in China.

Ormosia nuda is a legume species endemic to China. The chloroplast genome (plastome) of this species was assembled in this study. The total plastome size is 173,789 bp in length, containing a large single-copy (LSC) region of 73,847 bp, a small single-copy (SSC) region of 18,744 bp, and two inverted repeat (IR) regions of 40,599 bp which have expanded about 15 kb into LSC. The plastome encodes a total of 111 unique genes, including 77 protein-coding, 30 tRNA, and 4 rRNA genes. Phylogenetic analysis well resolved that O. nuda clustered with O. xylocarpa and O. emarginata. The plastome of O. nuda will provide informative genomic resources for further phylogenetic studies.

Exploration of Plastid Phylogenomic Conflict Yields New Insights into the Deep Relationships of Leguminosae.

Phylogenomic analyses have helped resolve many recalcitrant relationships in the angiosperm tree of life, yet phylogenetic resolution of the backbone of the Leguminosae, one of the largest and most economically and ecologically important families, remains poor due to generally limited molecular data and incomplete taxon sampling of previous studies. Here, we resolve many of the Leguminosae's thorniest nodes through comprehensive analysis of plastome-scale data using multiple modified coding and noncoding data sets of 187 species representing almost all major clades of the family. Additionally, we thoroughly characterize conflicting phylogenomic signal across the plastome in light of the family's complex history of plastome evolution. Most analyses produced largely congruent topologies with strong statistical support and provided strong support for resolution of some long-controversial deep relationships among the early diverging lineages of the subfamilies Caesalpinioideae and Papilionoideae. The robust phylogenetic backbone reconstructed in this study establishes a framework for future studies on legume classification, evolution, and diversification. However, conflicting phylogenetic signal was detected and quantified at several key nodes that prevent the confident resolution of these nodes using plastome data alone. [Leguminosae; maximum likelihood; phylogenetic conflict; plastome; recalcitrant relationships; stochasticity; systematic error.].

Plastid Genome Evolution in the Early-Diverging Legume Subfamily Cercidoideae (Fabaceae).

The subfamily Cercidoideae is an early-branching legume lineage, which consists of 13 genera distributed in the tropical and warm temperate Northern Hemisphere. A previous study detected two plastid genomic variations in this subfamily, but the limited taxon sampling left the overall plastid genome (plastome) diversification across the subfamily unaddressed, and phylogenetic relationships within this clade remained unresolved. Here, we assembled eight plastomes from seven Cercidoideae genera and conducted phylogenomic-comparative analyses in a broad evolutionary framework across legumes. The plastomes of Cercidoideae all exhibited a typical quadripartite structure with a conserved gene content typical of most angiosperm plastomes. Plastome size ranged from 151,705 to 165,416 bp, mainly due to the expansion and contraction of inverted repeat (IR) regions. The order of genes varied due to the occurrence of several inversions. In Tylosema species, a plastome with a 29-bp IR-mediated inversion was found to coexist with a canonical-type plastome, and the abundance of the two arrangements of isomeric molecules differed between individuals. Complete plastome data were much more efficient at resolving intergeneric relationships of Cercidoideae than the previously used selection of only a few plastid or nuclear loci. In sum, our study revealed novel insights into the structural diversification of plastomes in an early-branching legume lineage, and, thus, into the evolutionary trajectories of legume plastomes in general.

Interleukin-1ß induces the upregulation of caveolin-1 expression in a rat brain tumor model.

The aim of the present study was to investigate the expression of caveolin-1 in rat brain glioma tissue, and to determine whether interleukin-1ß (IL-1ß) has a role in this process. Using glioma cells, a tumor-burdened rat model was established, and the expression of caveolin-1 protein in the tumor sites was significantly increased following intracarotid infusion of IL-1ß (3.7 ng/kg/min), as indicated by western blot analysis. The maximum value of the caveolin-1 expression was observed in tumor-burdened rats after 60 min of IL-1ß perfusion, and which was significantly enhanced by vascular endothelial growth factor (VEGF). In addition, VEGF also significantly increased IL-1ß-induced blood tumor barrier (BTB) permeability. The results suggest that the IL-1ß-induced BTB permeability increase may be associated with the expression of caveolin-1 protein, and VEGF may be involved in this process.

Cyclooxygenase inhibitor induces the upregulation of connexin-43 expression in C6 glioma cells.

The present study was performed to determine whether aspirin, a cyclooxygenase (COX) inhibitor, has an effect on the expression of connexin 43 (Cx43) in C6 glioma cells. Using an in vitro glioma invasion model, the expression of Cx43 protein in C6 cells was significantly increased following aspirin treatment at a dose of 8 mmol/l for 30, 60 and 120 min via western blot analysis. The peak value of the Cx43 expression was observed in C6 cells after 120 min of aspirin treatment, which was significantly reduced by prostaglandin E2 (PGE2). In addition, aspirin also significantly increased the gap junction intercellular communication (GJIC) activity and reduced glioma invasion, which was induced by PGE2. This led to the conclusion that the aspirin-induced glioma invasion decrease may be associated with the increased expression of Cx43 protein and formation of GJIC.

[Morphological observation of human gastric cancer cell SGC-7901 clones and identification of gastric cancer stem cells].

OBJECTIVE: To dynamically investigate the morphology of human gastric cancer SGC-7901 cell clones, and then compare the tumorigenic ability of different clones in order to identify the tumor stem cell clones. METHODS: Clones derived from gastric cancer SGC-7901 cells were assessed by morphological observation, and the clone formation rate and proportion of each clone were calculated. The expression of CD44 and CDX2 in different clones was detected by immunofluorescence microscopy and Western blot. Furthermore, different clones were isolated and cultured, and their self-renewal property was assayed. Cells of different clones were subcutaneously inoculated into nude mice and the tumorigenic ability of each group was determined. RESULTS: Clones derived from gastric cancer SGC-7901 cells had three types, i.e. clones of tight, transitional and loose types. The total clone formation rate was (9.80 ± 1.07)%, and the proportion of tight, transitional and loose type clones was 10.2%, 56.0% and 33.8%, respectively. The results of immunofluorescence microscopic examination showed that the signal of CD44 was significantly stronger in the tight clones than in the transitional and loose clones, however, the signal of CDX2 was weakest in the tight colonies. The results of Western blot were consistent with that of immunofluorescence microscopic observation. SGC-7901 cells of tight clones possessed strong ability of self-renewal and in vivo tumorigenicity in the nude mice. CONCLUSION: SGC-7901 cell clones vary in morphology and differentiation, and the tight type clones may include rich gastric cancer stem cells.

Role of angiotensin-converting enzyme (ACE and ACE2) imbalance on tourniquet-induced remote kidney injury in a mouse hindlimb ischemia-reperfusion model.

In this study, the relationship between the local imbalance of angiotensin converting enzymes ACE and ACE2 as well as Ang II and Ang (1-7) and renal injury was observed in the different genotypes mice subjected to tourniquet-induced ischemia-reperfusion on hind limbs. In wild-type mice, renal ACE expression increased while renal ACE2 expression decreased significantly after reperfusion, accompanied by elevated serum angiotensin II (Ang II) level and lowered serum angiotensin (1-7) (Ang (1-7)) level. However, renal Ang (1-7) also increased markedly while renal Ang II was elevated. Renal injury became evident after limb reperfusion, with increased malondialdehyde (MDA), decreased super-oxide dismutase (SOD) activity and increased serum blood urea nitrogen (BUN) and creatinine (Cr), compared to control mice. These mice also developed severe renal pathology including infiltration of inflammatory cells in the renal interstitium and degeneration of tubule epithelial cells. In ACE2 knock-out mice with ACE up-regulation, tourniquet-induced renal injury was significantly aggravated as shown by increased levels of MDA, BUN and Cr, decreased SOD activity, more severe renal pathology, and decreased survival rate, compared with tourniquet-treated wild-type mice. Conversely, ACE2 transgenic mice with normal ACE expression were more resistant to tourniquet challenge as evidenced by decreased levels of MDA, BUN and Cr, increased SOD activity, attenuated renal pathological changes and increased survival rate. Our results suggest that the deregulation of ACE and ACE2 plays an important role in tourniquet-induced renal injury and that ACE2 up-regulation to restore the proper ACE/ACE2 balance is a potential therapeutic strategy for kidney injury.

[Effects of taurine on TNF-alpha and NF-kappaB expression of liver injury after limbs ischemia/reperfusion in rats].

AIM: To investigate the effect of pretreatment with taurine on liver injury changes and the change of tumor necrosis factor alpha and NFkappaB expression following rats limbs ischemia/reperfusion. METHODS: The model of limbs ischemia/reperfusion injury on rats was adopted in the experiment. Wistar rats were randomized into 4 groups (n = 10): Control group, T group, I/R group and TR group. Levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and MDA in the plasma, MDA, MPO, calcium in liver tissues were measured by colorimetric method. The content of TNF-alpha in plasma and liver tissues was determined by radioimmunoassay. The morphologic changes were observed with HE staining. The expressions of NF-kappaBp65 in liver tissues were tested by immuno-histochemistry method. RESULTS: It was found that against the control group, the test values of ALT, AST, et al. and expressions of TNF-alpha, NF-kappaB increased in I/R group and TR group, but values of those in TR group were lower than in I/R group. CONCLUSION: Taurine can decrease the levels of TNF-alpha and NF-kappaB. It can mitigate the liver injury after limb ischemia/reperfusion injury in rats.

Inhibition of signal transducer and activator of transcription 3 expression by RNA interference suppresses invasion through inducing anoikis in human colon cancer cells.

AIM: To investigate the roles and mechanism of signal transducer and activator of transcription 3 (STAT3) in invasion of human colon cancer cells by RNA interference. METHODS: Small interfering RNA (siRNA) targeting Signal transducer and activator of transcription 3 (STAT3) was transfected into HT29 colon cancer cells. STAT3 protein level and DNA-binding activity of STAT3 was evaluated by western blotting and electrophoretic mobility shift assay (EMSA), respectively. We studied the anchorage-independent growth using colony formation in soft agar, and invasion using the boyden chamber model, anoikis using DNA fragmentation assay and terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling (TUNEL), respectively. Western blot assay was used to observe the protein expression of Bcl-xL and survivin in colon cancer HT29 cells. RESULTS: RNA interference (RNAi) mediated by siRNA leads to suppression of STAT3 expression in colon cancer cell lines. Suppression of STAT3 expression by siRNA could inhibit anchorage-independent growth, and invasion ability, and induces anoikis in the colon cancer cell line HT29. It has been shown that knockdown of STAT3 expression by siRNA results in a reduction in expression of Bcl-xL and survivin in HT29 cells. CONCLUSION: These results suggest that STAT3 siRNA can inhibit the invasion ability of colon cancer cells through inducing anoikis, which antiapoptotic genes survivin and Bcl-xL contribute to regulation of anoikis. These studies indicate STAT3 siRNA could be a useful therapeutic tool for the treatment of colon cancer.

[Effect of ischemic preconditioning on lung injury induced by ischemia/reperfusion in the hind limbs of rats].

AIM: To study the effect of ischemic preconditioning on lung injury following ischemia/reperfusion (I/R) in the hind limbs of rats. METHODS: Wistar rats were randomly divided into four groups (n=8): control group,limbs ischemia/reperfusion (LI/R) group, ischemia preconditioning (IPC) group and L-NAME group. At the end of the experiment, blood/gas analysis and the contents of serum MDA, NO, ET and lung tissue MDA, NO, ET, MPO were measured. Meanwhile, lung index and W/D) of lung were measured. RESULTS: After the rats' hind limbs suffered ischemia/reperfusion, the level of PaO2 decreased and the values of W/D, LI, MPO of the lung issure and MDA, NO, ET of plasma and lung all increased significantly in the LI/R group; but the ratio of NO/ET decreased. Compared with LI/R group, the contents of NO and ratio of NO/ET increased but other parameters decreased in the IPC group. Compared with IPC group, the contents of NO and ratio of NO/ET decreased, but other parameters increased in the L-NAME group. CONCLUSION: The IPC can attenuate lung injury following IR in the hind limbs of rats, which may correlated with the increase of NO.

[The affection and significance of NO on the expression of P-selectin in renal injury following hind limb ischemia/reperfusion in rats].

AIM: To probe into the affection and significance of NO on the expression of P-selectin in renal injury following hind limb ischemia/reperfusion in rats. METHODS: In accordance with the conventional approaches of our department, the model rats were prepared after they were made to undergo 4 hours or ischemia followed by 4 hours of reperfusion of hind limbs. The Wistar rats were divided into four groups randomly: Control group, LI/R group, L-Arg group and L-NAME group. And then in those four groups of Wistar rats, a series of values of measurement were determined such as: Plasma concentrations of nitric oxide (NO), blood urea nitrogen (BUN) and creatinine (Cr). Furthermore, biochemically there came to the assessment of the values including myeloperoxidase (MPO), NO, total nitric oxide synthase (tNOS), inducible NOS (iNOS) and constitutive NOS (cNOS) of renal tissue in different groups. By the methods of electrophoresis and biochemistry, the urine protein was mensurated. The immunohistochemical method was used to detect the expression of P-selectin protein. The morphologic changes were observed with a microscope. RESULTS: After hind limbs had suffered from ischemia/reperfusion for 4 hours, there was the occurrence of a series of results such as in the following which were based on the comparison between plasm of LI/R group and control group. The values of NO, BUN and Cr increased significantly, and the trend of indexes such as NO in renal tissue was similar to that in plasma. The values of MPO, tNOS and iNOS in renal tissue all increased significantly after reperfusion, while cNOS decreased distinctly. The urine protein appeared, especially large molecular weight protein. Renal pathology revealed that after LI/R there were edema and infiltration of polymorphonuclear neutrophil (PMN). Immunohistochemically, the expression of P-selectin was upregulated significantly. Compared with LI/R rats, all injury changes were alleviated in L-Arg group. Morphologic changes were mild. Both the content of urine protein and the percentage of apoptosis cell decreased. The expression of P-selectin was downregulated. In L-NAME group, all injury changes got worse. Immunohistochemical results showed strong positive staining of P-selectin. CONCLUSION: The renal injury after LI/R may relate to the strong expression of P-selectin. NO may have protective affection by decreasing the expression of P-selectin and alleviating the adhesion, aggregation and infiltration of neutrophils.