Arabidopsis kinesin KP1 specifically interacts with VDAC3, a mitochondrial protein, and regulates respiration during seed germination at low temperature.

The involvement of cytoskeleton-related proteins in regulating mitochondrial respiration has been revealed in mammalian cells. However, it is unclear if there is a relationship between the microtubule-based motor protein kinesin and mitochondrial respiration. In this research, we demonstrate that a plant-specific kinesin, Kinesin-like protein 1 (KP1; At KIN14 h), is involved in respiratory regulation during seed germination at a low temperature. Using in vitro biochemical methods and in vivo transgenic cell observations, we demonstrate that KP1 is able to localize to mitochondria via its tail domain (C terminus) and specifically interacts with a mitochondrial outer membrane protein, voltage-dependent anion channel 3 (VDAC3). Targeting of the KP1-tail to mitochondria is dependent on the presence of VDAC3. When grown at 4° C, KP1 dominant-negative mutants (TAILOEs) and vdac3 mutants exhibited a higher seed germination frequency. All germinating seeds of the kp1 and vdac3 mutants had increased oxygen consumption; the respiration balance between the cytochrome pathway and the alternative oxidase pathway was disrupted, and the ATP level was reduced. We conclude that the plant-specific kinesin, KP1, specifically interacts with VDAC3 on the mitochondrial outer membrane and that both KP1 and VDAC3 regulate aerobic respiration during seed germination at low temperature.

Characterization and expression profiling of cucumber kinesin genes during early fruit development: revealing the roles of kinesins in exponential cell production and enlargement in cucumber fruit.

Rapid cell division and expansion in early fruit development are important phases for cucumber fruit yield and quality. Kinesin proteins are microtubule-based motors responsible for modulating cell division and enlargement. In this work, the candidate kinesin genes involved in rapid cell division and expansion during cucumber fruit development were investigated. The morphological and cellular changes during early fruit development were compared in four cucumber genotypes with varied fruit size. The correlation between the expression profiles of cucumber kinesin genes and cellular changes in fruit was investigated. Finally, the biochemical characteristics and subcellular localizations of three candidate kinesins were studied. The results clarified the morphological and cellular changes during early cucumber fruit development. This study found that CsKF2-CsKF6 were positively correlated with rapid cell production; CsKF1 and CsKF7 showed a strongly positive correlation with rapid cell expansion. The results also indicated that CsKF1 localized to the plasma membrane of fast-expanding fruit cells, that CsKF2 might play a role in fruit chloroplast division, and that CsKF3 is involved in the function or formation of phragmoplasts in fruit telophase cells. The results strongly suggest that specific fruit-enriched kinesins are specialized in their functions in rapid cell division and expansion during cucumber fruit development.

The expression profiling of the lipoxygenase (LOX) family genes during fruit development, abiotic stress and hormonal treatments in cucumber (Cucumis sativus L.).

Lipoxygenases (LOXs) are non-haem iron-containing dioxygenases that catalyse oxygenation of polyunsaturated fatty acids and lipids to initiate the formation of a group of biologically active compounds called oxylipins. Plant oxylipins play important and diverse functions in the cells. In the current study, expression analysis during cucumber development using semi-quantitative RT-PCR revealed that 13 of 23 CsLOX genes were detectable, and were tissue specific or preferential accumulation. In total, 12 genes were found to be differentially expressed during fruit development and have different patterns of expression in exocarp, endocarp and pulp at day 5 after anthesis. The expression analysis of these 12 cucumber LOX genes in response to abiotic stresses and plant growth regulator treatments revealed their differential transcript in response to more than one treatment, indicating their diverse functions in abiotic stress and hormone responses. Results suggest that in cucumber the expanded LOX genes may play more diverse roles in life cycle and comprehensive data generated will be helpful in conducting functional genomic studies to understand their precise roles in cucumber fruit development and stress responses.

A summary of second systemic pulmonary shunt for congenital heart disease with pulmonary hypoxemia.

BACKGROUND: There has been an increasing number of children with congenital heart disease that undergo primary or second systemic-pulmonary shunt, while there are few reports on the second systemic-pulmonary shunt. Therefore, this study summarizes the experience of second systemic-pulmonary shunt for congenital heart disease in our hospital. METHODS AND RESULTS: Sixty-five children with congenital heart disease who underwent systemic-pulmonary shunt for the second time in our hospital were analyzed. At the early stage after the operation, cyanosis improved and SpO2 significantly increased. One patient died in hospital (1.54%) and the causes of death were aggravated atrioventricular regurgitation, low cardiac output syndrome, and liver failure. Early complications occurred in 18 patients (27.7%). All the children were rechecked in our hospital every 3-6 months and the McGoon index significantly increased. CONCLUSION: Systemic-pulmonary artery shunt can promote pulmonary vascular development, improve cyanosis symptoms, and increase the chance of radical treatment in children with pulmonary vascular dysplasia.

Recruitment of AtWHY1 and AtWHY3 by a distal element upstream of the kinesin gene AtKP1 to mediate transcriptional repression.

A 43-bp distal element, the AtKP1-related element (KPRE), was previously shown to repress the promoter activity of the kinesin gene AtKP1 in Arabidopsis thaliana. In order to identify KPRE-binding factor 1 (KBF1), a combination of ion-exchange chromatography, gel-filtration chromatography and DNA-affinity chromatography was used to purify KBF1 from whole cell extracts of Arabidopsis seedlings. Mass spectrometric identification showed that KBF1 contains two members of the whirly family of transcription factors, AtWHY1 and AtWHY3. KBF1 is a single and double-stranded DNA-binding factor. A ChIP assay showed that AtWHY1 and AtWHY3 bind to the upstream region of AtKP1 gene in vivo. Over-expression of AtWHY1 and AtWHY3 led to an obvious decrease of AtKP1 transcripts, based on quantitative real-time PCR analysis. Interestingly, salicylic acid treatment resulted in an increase of AtWHY1 and AtWHY3 transcripts, and a decrease of AtKP1 transcripts. Thus, AtWHY1 and AtWHY3, as two components of KBF1, can be recruited at the KPRE site to mediate the transcriptional repression of AtKP1. Our results prove that AtKP1 is a new downstream target of the whirly family of transcription factors.

Effect of nitrogen deficiency on ascorbic acid biosynthesis and recycling pathway in cucumber seedlings.

L-Ascorbic acid (AsA, ascorbate) is one of the most abundant natural antioxidants, and it is an important factor in the nutritional quality of cucumber. In this work, key enzymes involved in the ascorbic acid biosynthesis and recycling pathway in cucumber seedlings under nitrogen deficiency were investigated at the levels of transcription and enzyme activity. The activities of myo-inositol oxygenase (MIOX) and transcript levels of MIOXs increased dramatically, while the activities of ascorbate oxidase (AO) and glutathione reductase (GR) and transcript levels of AOs and GR2 decreased significantly in N-limited leaves, as did the ascorbate concentration, in nitrogen-deficient cucumber seedlings. The activities of other enzymes and transcript levels of other genes involved in the ascorbate recycling pathway and ascorbate synthesis pathways decreased or remained unchanged under nitrogen deficiency. These results indicate that nitrogen deficiency induced genes involved in the ascorbate-glutathione recycling and myo-inositol pathway in cucumber leaves. Thus, the AO, GR and MIOX involved in the pathways might play roles in AsA accumulation.

Correlation between GATA4 gene polymorphism and congenital heart disease.

OBJECTIVE: The correlation between GATA4 gene polymorphism and congenital heart disease (CHD) was analyzed. METHOD: Clinical data and blood samples were collected from 350 CHD patients who were treated at the Department of Cardiology in Beijing Anzhen Hospital. The control group consisted of 350 healthy subjects receiving physical examination at our hospital during the same period. Polymorphism was detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis for locus rs11392441 of GATA4 gene. RESULTS: Polymorphism of locus rs1139244 of GATA4 gene was detected in CHD patients. The distribution frequencies of GG genotype and G allele were significantly higher than those of the control group. CONCLUSION: Polymorphism of locus rs1139244 of GATA4 gene was correlated with CHD.

[Effects of pulmonary surfactant in treatment of acute lung injury after cardiac surgery in infants].

OBJECTIVE: Acute lung injury is a severe complication after cardiac surgery performed with cardiopulmonary bypass in infant patients. Pulmonary surfactant has been successfully used in treating neonatal respiratory distress syndrome for many years. This study focused on exploring the clinical efficacy of exogenous pulmonary surfactant in treating infant patients with acute lung injury after cardiac surgery with the use of extracorporeal circulation. METHOD: Twenty-three infants with ventricular septal defect (VSD) were enrolled in the study. None of the patients needed oxygen treatment nor ventilation before heart surgery. VSD repair operation was done under cardiopulmonary bypass, and acute lung injury was found postoperatively. Ten infant patients in the treatment group were given pulmonary surfactant by tracheal instillation during mechanical ventilating postoperatively. Thirteen patients in control group were randomly selected in the same period in hospital, and acute lung injury was diagnosed without pulmonary surfactant treatment after cardiopulmonary bypass. Blood samples were obtained from all the patients, and blood gas analysis was performed every 6 hours. Demographics (body weigh, age, gender, VSD diameter) and clinical characteristics (CPB time, oxygenation index, mean airway pressure, pH and PCO2) of all the patients were collected, and statistical analysis was done to compare the data between treatment and control group. RESULT: In the first 24 hours after heart surgery, compared with the control group, a more increased oxygenation index (from 89.36 ± 12.69 to 285 ± 16.51) was observed in treatment group, and it was from 93.71 ± 11.82 to 133 ± 19.62 in the control group. There was a significant difference in oxygenation index between the two groups (P < 0.05). At the same time, the MAP (from 17.5 ± 3.18 to 10.4 ± 3.37) of the patients in comparison with the control group (from 18.2 ± 2.63 to 13.8 ± 2.55), a more significantly decreased MAP was observed in the treatment group (P < 0.05). There was no significant difference in pH and PCO2 between the two groups. The ventilation time in cardiac care unit was shorter in treatment group (17.43 ± 9.12) h compared with the control group [(30.97 ± 14.85) h, P < 0.05]. ICU stay time of treatment group (3.90 ± 1.34) d was shorter than that of control group [(6.18 ± 1.90) d, P < 0.05].Two infants of the control group died, but none in treatment group died. CONCLUSION: In this study, a satisfactory curative effect was observed for the treatment of acute lung injury with PS intratracheal instillation after heart surgery under cardiopulmonary bypass in infant patients. It can reduce the duration of mechanical ventilation and cardiac care unit stay and improve prognosis. In addition, this study was a pilot study and the limited sample size was probably the cause of insufficient statistical power. Further study of larger scale is needed.

Incidence of congenital heart disease in Beijing, China.

BACKGROUND: The incidence of congenital heart disease has been studied in developed countries for many years, but rarely in the mainland of China. Fetal echocardiographic screening for congenital heart disease was first performed in Beijing in the early 2000s, but the impact was not clear. The current study was undertaken to determine the incidence of congenital heart disease in Beijing, China and to estimate the impact of fetal echocardiography on the incidence of liveborn congenital heart disease. METHODS: The study involved all infants with congenital heart disease among the 84 062 total births in Beijing during the period of January 1 and December 31, 2007. An echocardiographic examination was performed on every baby suspected to have congenital heart disease, prenatally or/and postnatally. RESULTS: A total of 686 infants were shown to have congenital heart disease among 84 062 total births. The overall incidence was 8.2/1000 total births. Mothers of 128 of 151 babies diagnosed prenatally were chosen to terminate the pregnancy. Two of the 151 infants died in utero. A specific lesion was identified for each infant and the frequencies of lesions were determined for each class of infants (total births, stillbirths and live births). The incidence of congenital heart disease in stillbirths and live births was 168.8/1000 and 6.7/1000, respectively. The difference between the incidence of total birth and the incidence of live birth was statistically significant (P < 0.001). CONCLUSIONS: The incidence of liveborn congenital heart disease in Beijing is within the range reported in developed countries. Fetal echocardiography reduce significantly the incidence of liveborn congenital heart disease.