ProSAAS processing in mouse brain and pituitary

ProSAAS is a newly discovered protein with a neuroendocrine distribution generally similar to that of prohormone convertase 1 (PC1), a peptide-processing endopeptidase. Several proSAAS-derived peptides were previously identified in the brain and pituitary of the Cpe(fat)/Cpe(fat) mouse based on the accumulation of C-terminally extended peptides due to the absence of enzymatically active carboxypeptidase E, a peptide-processing exopeptidase. In the present study, antisera against different regions of proSAAS were used to develop radioimmunoassays and examine the processing profile of proSAAS in wild type and Cpe(fat)/Cpe(fat) mouse tissues following gel filtration and reverse phase high performance liquid chromatography. In wild type mouse brain and pituitary, the majority of proSAAS is processed into smaller peptides. These proSAAS-derived peptides elute from the reverse-phase column in the same positions as synthetic peptides that correspond to little SAAS, PEN, and big LEN. Mass spectrometry revealed the presence of peptides with the expected molecular masses of little SAAS and big LEN in the fractions containing immunoreactive peptides. The processing of proSAAS is slightly impaired in Cpe(fat)/Cpe(fat) mice, relative to wild-type mice, leading to the accumulation of partially processed peptides. One of these peptides, the C-terminally extended form of PEN, is known to inhibit PC1 activity and this could account for the reduction in enzymatically active PC1 seen in Cpe(fat)/Cpe(fat) mice. The observation that little SAAS and big LEN are the major forms of these peptides produced in mouse brain and pituitary raises the possibility that these peptides function as neurotransmitters or hormones.     

Regulation of alternative splicing of Bcl-x by IL-6, GM-CSF and TPA

The splicing of many alternative exons in the precursor messenger RNA (pre-mRNA) is regulated by extracellular factors but the underlying molecular bases remain unclear. Here we report the differential regulation of Bcl-x pre-mRNA splicing by extracellular factors and their distinct requirements for pre-mRNA elements. In K562 leukemia cells, treatment with interleukin-6 (IL-6) or granulocyte-macrophage colony stimulating factor (GM-CSF) reduced the proportion of the Bcl-xL variant mRNA while treatment with 12-O-tetradecanoylphorbol 13-acetate (TPA) had no effect. In U251 glioma cells, however, TPA efficiently increased the Bcl-xL level. These regulations were also seen for a transfected splicing reporter mini-gene. Further analyses of deletion mutants indicate that nucleotides 1-176 of the downstream intron are required for the IL-6 effect, whereas additional nucleotides 177-284 are essential for the GM-CSF effect. As for the TPA effect, only nucleotides 1-76 are required in the downstream intron. Thus, IL-6, GM-CSF and TPA differentially regulate Bcl-x splicing and require specific intronic pre-mRNA sequences for their respective effects.     

长期游泳运动对大鼠铁状态的影响

目的：观察不同的运动时间对铁状态的影响。方法：大鼠随机分为3、6、12个月的三个游泳运动组和相应安静组;运动期满后观察血液学铁状态指标和器官非血红素铁(NHI)含量和NHI总含量(TNHI)的变化。结果：与安静组相比,三种不同时间长度的运动均诱导一种具有血浆铁浓度降低、血浆转铁蛋白铁饱和度降低而血红蛋白浓度和红细胞比容得到雏持的血液学低铁状态;这种低铁状态伴有肝、脾、心、肾NHI浓度显著降低,但与运动时间无关;肝、脾和肾TNHI变化与其浓度变化方向一致,但心脏没有显著变化;上述器官TNHI随时间增加而增多。结论：尽管运动诱导的低铁状态类似于铁缺乏中期表现,但由于器官NHI重分布和铁贮存并没有进行性降低,因此,长期运动引起的低铁状态可能是机体内铁代谢对运动的适应,不存在所谓“运动性铁缺乏”现象。     

Ohmefentanyl stereoisomers induce changes of CREB phosphorylation in hippocampus of mice in conditioned place preference paradigm

The present study was designed to determine the changes of phosphorylation of cAMP-response element binding protein(CREB)in hippocampus induced by ohmefentanyl stereoisomers(F9202 and F9204) in conditioned place preference(CPP)paradigm.The results showed that mice receiving F9202 and F9204 displayed obvious CPP.They could all significantly stimulate CREB phosphorylation and maintained for a long time without affecting total CREB protein levels.The effect of F9204 was similar to morphine which effect was more potent and longer than F9202.We also examined the effects of ketamine,a noncompetitive N-mthyl-D-asartate receptor(NR)antagonist,on morphine-,F9202-and F9204-induced CPP and phosphorylation of CREB in hippocampus.Ketamine could suppress not only the place preference but also the phosphorylation of CREB produced by morphine,F9202 and F9204.These findings suggest that alterations in the phosphorylation of CREB be relevant to opiates signaling and the development of opiates dependence.NR antagonists may interfere with opiates dependence and may have potential therapeutic implications.     

Assessment of RAPD markers for barley doubled haploid lines resistant and susceptible to Fusarium culmorum at seedling and adult plant growth stages

Thirty doubled haploid (DH) lines of barley derived from F(1) of a cross between the six-rowed cultivar Pomo and two-rowed cultivar Maresi were examined for susceptibility to Fusarium seedling blight (SB) and head blight (FHB), measured by mycotoxin (nivalenol) content of kernels. RAPD (random amplified polymorphic DNA) polymorphism was analysed by using 53 decamer primers. Amplification products (APs) were 200 bp up to 2000 bp in size on average 5.7 per primer and the total number of APs was 284, 51.06% of which were polymorphic. Only 32 APs differentiated the examined DH lines - 19 APs for nivalenol content of kernels and 13 for seedling resistance. DH lines segregated with continuous distribution of resistance to FHB and SB. At the seedling stage all DH lines exhibited lower susceptibility than parental cultivars, but in the adult stage only two lines (MP 2 and MP 7) appeared to be more resistant to FHB, i.e. accumulated in kernels a lower amount of mycotoxin than cultivars Maresi and Pomo.     

Effects of thioredoxin on the preimplantation development of bovine embryos

Thioredoxin (TRX) is an ubiquitous protein disulfide reductase, which is known to be involved in the implantation development of mouse embryos. In the present study, recombinant human TRX was used to evaluate its effect on the promotion of preimplantation development of bovine embryos derived from in vitro maturation and fertilization. Supplementation of the medium 24h post insemination with TRX significantly (P<0.05) enhanced the frequency of development to the blastocyst stage in 5% O(2) concentration. The optimal concentration was 0.5 microg/ml (P<0.05, compared with 0, 0.1 and 1.0 microg/ml). This effect of TRX was evident only when added around the time of the first cleavage stage (24 h post insemination); no promotion was found with treatment at 6h (one-cell) or 44 h (six- to eight-cell) after insemination. Moreover, it is of interest that even with the best combination of the dose and timing of TRX treatment (0.5 microg/ml, at 24 h post insemination), no promotion of development was observed when embryos were cultured under 20% O(2). However, a preincubation of TRX in the culture medium under 20% oxygen for 24h did not diminish the promoting effect in the subsequent TRX treatment under optimal conditions, thus suggesting that the possible oxidation of TRX alone may not be the reason for the disappearance of the effect under a high oxygen concentration. These results indicate that TRX does improve the development of bovine embryos in vitro, though unlike the general reducing reagents such as beta-mercaptoethanol or cysteamine, TRX may have to exert its effect at specific times and in more physiologic oxygen environments.     

Fibroblast Activation Protein Overexpression and Clinical Implications in Solid Tumors: A Meta-Analysis

Objective

Fibroblast activation protein (FAP) plays a vital role in tumor invasion and metastasis. Previous studies have reported its prognostic value in different tumors. However, the results of these reports remain controversial. In this study, a meta-analysis was performed to clarify this issue.

Methods

A search of the PubMed, Embase and CNKI databases was conducted to analyze relevant articles. The outcomes included the relations between FAP expression and histological differentiation, tumor invasion, lymph node metastasis, distant metastasis and overall survival (OS). Sensitivity analysis by FAP expression in different cells and tumor types were further subjected to sensitivity analyses as subgroups. Pooled odds ratios (ORs) and hazard ratios (HRs) were evaluated using the random-effects model.

Results

The global analysis included 15 studies concerning various solid tumors. For global analysis, FAP overexpression in tumor tissue displayed significant associations with poor OS and tumor progression (OS: HR = 2.18, P = 0.004; tumor invasion: OR = 4.48, P = 0.007; and lymph node metastasis: OR = 3.80, P = 0.004). The subgroup analyses yielded two notable results. First, the relation between FAP overexpression and poor OS and tumor lymph node metastasis was closer in the patients with FAP expression in tumor cells. Second, the pooled analyses of colorectal cancers or pancreatic cancers all indicated that FAP overexpression was associated with a detrimental OS (HR: 1.72, P = 0.009; HR: 3.18, P = 0.005, respectively). The magnitude of this effect was not statistically significant compared with that in patients with non-colorectal cancers or non-pancreatic cancers. These analyses did not display a statistically significant correlation between FAP expression and histological differentiation and distant metastasis in all of the groups.

Conclusions

FAP expression is associated with worse prognosis in solid tumors, and this association is particularly pronounced if FAP overexpression is found in the tumor cells rather than the stroma.