Fine mapping of a gene for non-pollen type thermosensitive genic male sterility in rice (Oryza sativa L.)

The thermo-sensitive genic male sterility (TGMS) lines play a crucial role in two-line hybrid rice production. For a practical TGMS line, the stability of male sterility is one of the most important technical indicators. In this study, XianS, a spontaneous mutant with stable male sterility from an indica rice cultivar Xianhuangzhan, was classified as a non-pollen type TGMS line. The critical non-pollen sterility point temperature of XianS was determined as 27 degrees C. Genetic analysis demonstrated that the non-pollen sterility in XianS was controlled by a single recessive gene. Using SSR markers and bulked segregant analysis, the TGMS gene in XianS was fine mapped to a 183 kb interval between RMAN81 and RMX21 on chromosome 2. Two markers, 4039-1 and RMX14 completely cosegregated with this gene. Allelism test indicated that the non-pollen phenotype in seven non-pollen type TGMS lines from different sources, XianS, AnnongS-1, Q523S, Q524S, N28S, G421S, and Q527S is caused by the same TGMS gene. Although the location of TGMS gene in XianS is close to the gene OsNAC6, a previously identified candidate gene of tms5 in AnnongS-1, the sequence of OsNAC6 and its promoter region was identical in TGMS line XianS, AnnongS-1, and wild-type Xianhuangzhan. These results suggest that the non-pollen type TGMS trait probably be controlled by the same TGMS gene in different TGMS rice lines, but its real candidate gene still need to be further studied and identified.

Preparation of the acellular scaffold of the spinal cord and the study of biocompatibility

STUDY DESIGN

Acellular spinal cord was prepared through chemical extraction, and its biocompatibility was studied.

OBJECTIVE

Acellular scaffolds have been developed from various materials for tissue reconstruction, except for spinal cord. The objective of this study was to prepare acellular spinal cord and examine the biocompatibility of the scaffold.

SETTING

This study was conducted at the Department of Orthopedics, Xinqiao Hospital, The Third Military Medical University, Chongqing, China.

METHODS

The morphology of the acellular segments was revealed by scanning electron microscopy, immunohistochemistry, and hematoxylin and eosin stain. Biocompatibility was studied by immunohistochemistry.

RESULTS

Results show that in spinal cord scaffolds, cells, myelin sheath and axon of nerve fibers were eliminated, and three-dimensional supports of extracellular matrix were reserved. The component analytical results of the acellular spinal cord indicate that they contain laminin, fibronectin and collagen, which can facilitate and induce the regeneration of injured nerves, and enhance the adhesion and proliferation of cells. The acellular spinal cord has a three-dimensional structure and excellent biocompatibility.

CONCLUSION

Our data indicate that acellular spinal cord has certain biological properties and it may be a potential alternative scaffold for spinal cord tissue engineering.

Genetic Polymorphisms of MTHFR and Aberrant Promoter Hypermethylation of the RASSF1A Gene in Bladder Cancer Risk in a Chinese Population

Epidemiological studies have shown that folate deficiency increases the risk of cancer by affecting DNA repair and methylation. Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in folate metabolism. In this study, it was hypothesized that MTHFR (C677T and A1298C) polymorphisms would be associated with bladder cancer and also with hypermethylation of the promoter of the Ras association domain family 1A (RASSF1A) gene. This hospital-based, case-control study of 312 bladder cancer patients and 325 cancer-free controls found that individuals carrying the MTHFR 677TT genotype had a 2.00-fold increased risk of bladder cancer compared with those carrying the 677CC genotype. None of the MTHFR A1298C polymorphisms alone were associated with bladder cancer, but the combined haplotype 677TT/1298AA was associated with a 2.27-fold increased risk compared with haplotype 677CC/1298AA. There was no association between MTHFR gene variants and methylation status of the RASSF1A gene in the 45 bladder cancer patients in whom this was studied. It is concluded that the MTHFR 677TT genotype and the TTAA haplotype may increase the risk of bladder cancer.

Brazilein inhibits survivin protein and mRNA expression and induces apoptosis in hepatocellular carcinoma HepG2 cells

Hepatocellular carcinomas represent the third leading cause of cancer-related deaths worldwide. Survivin, a structurally unique member of the inhibitor of apoptosis protein (IAP) family, is overexpressed in a wide range of malignancies, including hepatocellular carcinoma. Due to its involvement in cancer progression and treatment resistance, survivin is currently undergoing extensive investigation as a novel intervention target to induce apoptosis in cancer cells by phytochemicals or synthetic agents. Brazilein, a compound obtained in a large amount from the dried heartwood of Caesalpinia sappan Linn., which has long been used in traditional medicine in China, has some pharmacological activities. Human hepatocellular carcinoma HepG2 cells were treated with brazilein and analyzed for survivin protein and mRNA levels by Western blotting and real-time RT-PCR, respectively. Brazilein treatment of cells for 48 h at 5 and 10 microg/ml doses resulted in significantly decrease in survivin protein expression. We also observed that brazilein caused a strong decrease in survivin mRNA expression. In other studies, down-regulation of survivin by brazilein was associated with a strong and prominent caspases-9 and -3 activation as well as PARP cleavage. It was also shown that brazilein induced a strong apoptotic cell death, as shown by DNA ladder assay, and growth inhibition of HepG2 cells. Further studies are needed to investigate in vivo effect of brazilein on survivin expression and associated biological effects in hepatocellular carcinoma that could provide useful information for brazilein efficacy in the prevention/intervention of human hepatocellular carcinoma.

Optimization of Xhhh strain biodegradation with metal ions for pharmaceautical wastewater treatment

Effects of three ions, Mn2+, Cu2+ and Zn2+ on biological treatment of pharmaceutical wastewaterby a functional strain Xhhh were investigated. Through orthogonal tests, Cu2+ was determined to be the most important factor influencing Xhhh biodegradation performance. Biodegradation kinetic experiments demonstrated that with Cu+ concentration at about 200 mg l(-1), the maximum of specific growth rate and specific degradation rate were obtained to be 0.033 and 0.075 d(-1), respectively. The optimal levels of Mn2+ (5.00 mg I(-1)), Cu2+ (2.00 mg l(-1)) and Zn2+ (5.00 mg l(-1)) were achieved based on experimental results of their effects on the activities of manganese peroxidase and lignin peroxidase, and biodegradation kinetic parameters. Among three types of biodegradation kinetic models (Monod, Tessier and Contois), Tessier model was found most reasonable for kinetics description of Xhhh growth (R2 = 0.995) and pollutants degradation (R2 = 0.970) in the case of metals optimization. Both kinetics evaluation and experimental results demonstrated that optimization with the three metals made a great contribution to Xhhh growth and COD removal for pharmaceutical wastewater treatment.

Lifespan influences on mid- to late-life cognitive function in a Chinese birth cohort

OBJECTIVE

To explore factors throughout the lifespan that influence cognition in midlife to late life.

METHODS

We conducted a retrospective birth cohort study of 2,062 individuals born during 1921-1954 in Beijing, China. In 2003-2005, birth records were abstracted, and participants then 50-82 years old received standardized examinations for health, cognition, and socio-environmental measures. Using cumulative logit models, we assessed adjusted relative effects of prenatal, early life, and adult factors on mid- to late-life cognition.

RESULTS

Most prenatal factors were associated with mid- to late-life cognition in the unadjusted models. However, when childhood and adult factors were sequentially added to the models, the impact of prenatal factors showed successive attenuation in effect size, and became insignificant. In contrast, early life factors remained significantly associated with mid- to late-life cognition even after full life-course adjustments. Specifically, those whose fathers had laborer vs professional occupations (odds ratio [OR](Laborer) 1.74; 95% confidence interval [CI]: 1.25-2.42) had poorer cognitive outcomes, while individuals who drank milk daily in childhood (OR 0.65; 95% CI: 0.54-0.80), had more years of education (OR(10-12 years) 0.60; 95% CI: 0.45-0.81; OR(13+ yrs) 0.29; 95% CI: 0.23-0.38), and were taller adults (OR(height > or = SD) 0.65; 95% CI: 0.49-0.86) had better cognition. The high prenatal risk infants had similar patterns with a trend toward a stronger association between cognition and socioenvironmental factors.

CONCLUSION

Mid- to late-life cognition is influenced by factors over the entire lifespan with the greatest impact coming from early life exposures. Nutrition, education, social, and family environment in early life may have a long-term impact on cognition in developing countries.

Mutations in the LDL receptor gene in four Chinese homozygous familial hypercholesterolemia phenotype patients

BACKGROUND AND AIMS

Familial hypercholesterolemia (FH) is an autosomal dominant disorder of lipoprotein metabolism caused by mutations in the low-density lipoprotein receptor (LDL-R) gene, leading to elevated levels of cholesterol and an increased risk of coronary heart disease. In this article, from four homozygous FH phenotype probands we identified disease causing mutations and analyzed the relationship between genotype and phenotype.

METHODS AND RESULTS

DNA sequencing identified five LDL-R point mutations in four unrelated families. We found a novel homozygous mutation (C210R), a homozygous mutation at W462X, a compound heterozygous mutation of C122Y and T383I, and a G>A intron 3 splice site homozygous mutation. The functional alteration caused by the novel C210R mutation was confirmed by FACS analysis. Four probands have high low-density lipoprotein cholesterol (LDL-C) levels, ranging from 14.65 to 27.66 mmol/L. Their heterozygous parents had relatively low levels. B-mode ultrasound supplemented by Doppler was used to examine aortic/mitral valve structural alterations and carotid intima-media thickness (ITM) in all probands. The ITM values were between 1.2 and 2.3mm, much higher than the normal value of <0.8mm.

CONCLUSION

Our data demonstrated that all the probands were associated with severe hypercholesterolemia, thick carotid IMT and a low CFVR (coronary flow velocity reserve) value. The novel mutation (C120Y) is a disease causing mutation.

Correlative tumor molecular profiling and plasma biomarker analysis in a phase II study of XL184 in patients with progressive or recurrent glioblastoma multiforme (GBM)

2049

Background: XL184 is an oral inhibitor of MET, RET, KIT, and VEGFR-2 with potent antitumor effects in preclinical models of GBM. Clinically, elevated levels of MET, KIT, VEGFR-2, and VEGF-A are found in GBM, where MET and KIT levels correlate with poor prognosis. XL184–201 is a fully enrolled GBM study (N = 46) which mandated collection of archival tumors and serial plasma samples. The encouraging clinical activity of XL184 in this study is the subject of a separate abstract. Methods: Tumor profiling focused on genomic alterations prevalent in GBM, reflecting dysregulation of key signaling pathways (Nature 2008; 455:1061), or XL184 targets. Plasma samples were analyzed with ELISA assays. Correlation of results with clinical outcomes is a secondary objective of study XL184–201. Results: Tumor genotyping assessments included EGFR and KIT copy number; PTEN, PIK3CA, PIK3R1, and NF1 sequencing, as well as MGMT and PTEN promoter methylation. Results from the first 12 cases indicate sequence variations & frequencies similar to reports in the literature. IHC analysis of MET, RET, and VEGFR-2 protein expression was also performed. In ∼ 80% of samples, tumor cells stained positive for MET with a lower fraction positive for RET and VEGFR-2 in tumor cells (42% and 58%, respectively). RET and VEGFR-2 expression was often seen in tumor-associated blood vessels, while MET signal in blood vessels was more limited (33%). Preliminary biomarker analysis established significant modulation of plasma levels of VEGF-A, sMET, sVEGFR-2, sKIT, and PlGF, consistent with multiple on target effects. Objective response was observed in the presence or absence of tumor EGFR amplification, PTEN mutation, and MGMT promoter methylation. The potential predictive value of these and other biomarkers is under investigation. Conclusions: Plasma biomarkers confirm pharmacodynamic activity of XL184 in advanced GBM where marked clinical activity has been observed. Upon completed analysis of a full set of biological samples and with mature clinical data, predictive markers for clinical activity of XL184 will be evaluated.

[Table: see text]

Effects of disulfide bridges glycoprotein E1 on fusogenic activity of Rubella virus

Rubella virus (RUBV) infects cells via an acid-triggered membrane fusion process. RUBV virions contain two cysteine-rich glycoproteins, E2 and E1. The latter is believed to be involved in the membrane fusion. Using a recombinant plasmid containing RUBV E1 and E2, 11 of total 20 cysteines present in the ectodomain of wild type E1 were mutated to test their role in the fusion via the formation of disulfide bridges. The recombinant plasmids containing mutated E1 (Cys2-Cys20) or wild type (wt) E1 were expressed in BHK-21 cells. Their fusogenic and hemadsorption activities in addition to a potential of cell surface expression of E1 and E2 were assayed. The results showed that the fusogenic activity was lost in all tested mutants, while the hemadsorption activity and cell surface expression potential were affected differently in individual mutants. Since only the Cys5 and Cys8 mutations led to a reduction of both hemadsorption and cell surface expression, we assume that these mutations prevented the formation of the disulfide bridge, what led to a misfolding of E1 and consequently to a failure of recognition of E1 by E2. In conclusion, the disulfide bridges disrupted in all the tested mutants appear essential for the cell fusion, while only the disulfide bridge C(5)-C(8) seems to be crucial for the transport of E1 and E2 in the cell.