miR167d-ARFs Module Regulates Flower Opening and Stigma Size in Rice.

Flower opening and stigma exertion are two critical traits for cross-pollination during seed production of hybrid rice (Oryza sativa L.). In this study, we demonstrate that the miR167d-ARFs module regulates stigma size and flower opening that is associated with the elongation of stamen filaments and the cell arrangement of lodicules. The overexpression of miR167d (OX167d) resulted in failed elongation of stamen filaments, increased stigma size, and morphological alteration of lodicule, resulting in cleistogamy. Blocking miR167d by target mimicry also led to a morphological alteration of the individual floral organs, including a reduction in stigma size and alteration of lodicule cell morphology, but did not show the cleistogamous phenotype. In addition, the four target genes of miR167d, namely ARF6, ARF12, ARF17, and ARF25, have overlapping functions in flower opening and stigma size. The loss-of-function of a single ARF gene did not influence the flower opening and stigma size, but arf12 single mutant showed a reduced plant height and aborted apical spikelets. However, mutation in ARF12 together with mutation in either ARF6, ARF17, or ARF25 led to the same defective phenotypes that were observed in OX167d, including the failed elongation of stamen filaments, increased stigma size, and morphological alteration of lodicule. These findings indicate that the appropriate expression of miR167d is crucial and the miR167d-ARFs module plays important roles in the regulation of flower opening and stigma size in rice.

Factors influencing the rate of residual stenosis in athletic patients after endovascular intervention for symptomatic carotid artery stenosis

Objective: High residual stenosis after endovascular treatment was a risk factor for postoperative stenosis in athletic patients with symptomatic carotid artery stenosis. This study investigated the factors influencing the residual stenosis rate after endovascular interventional therapy for symptomatic carotid artery stenosis.Methods: This study involved 337 athletic patients with symptomatic carotid artery stenosis (191 in a residual stenosis group and 186 in a non-residual stenosis group). To obtain differences in distribution between residual and non-residual stenosis groups, the variables of baseline information were dichotomized by median value and compared by chi-square test. In addition, we screened the categorical variables for each risk factor by a single-factor linear regression model and then determined the final influencing factors by the stepwise regression model.Results: Among the 377 athletic patients with symptomatic carotid artery stenosis, 191 (50.66%) developed residual stenosis after interventional recanalization procedures. Analysis of single-factor linear regression model showed that age and NLR were statistically significant (P<0.05) even during the continuous change in residual stenosis rate, and there was a positive correlation between them. Stepwise regression analysis showed that age and NLR were positive correlated with the occurrence of residual stenosis after excluding possible confounding factors, which was consistent with the results of the single-factor linear regression model (P<0.05).Conclusion: NLR, as a notable predictor of inflammation, had an important predictive value for the occurrence of residual stenosis after EVT. In addition, age of athletic patients also increased the risk of residual stenosis to some extent. (AU)

[The effect of selectively inhibiting the nuclear factor kappaB activation on survivin expression in leukemic cells].

OBJECTIVE: To investigate the highly specific proteasomal inhibitor MG132-induced apoptosis and its effect on nuclear factor (NF)-kappaB activation and survivin expression in leukemic K562 cell line. METHODS: leukemic cells of the line K562 were cultured and divided into 2 groups: treatment group, undergoing co-incubation with MG132 of the concentrations of 2, 4, 6, and 8 micromol/L respectively for 24 hours, and control group without treatment of MG132. Apoptosis was detected by examination of cell morphology and flow cytometry. Survivin expression and NF-kappaB activation were analyzed by immunocytochemistry and Western blotting. RESULTS: MG132 induced apoptosis of the K562 cells dose-dependently. Both survivin and NF-kappaB were highly expressed in the K562 cells. Compared with the control group, K562 cell treated with MG132 at the concentrations of 2, 4, 6, and 8 micromol/L for 24 hours showed the decrease of NF-kappaB activation to 75.0% +/- 3.7%, 59.9% +/- 5.3%, 45.4% +/- 5.7%, and 25.0% +/- 4.2% respectively, and decrease of survivin expression to 90.9% +/- 10.1%, 66.7% +/- 5.2%, 45.4% +/- 5.7%, and 30.3% +/- 6.6% respectively. Downregulation of survivin expression was closely correlated with the inhibition of NF-kappaB activation (Pearson correlation coefficient = 0.989, P < 0.01). CONCLUSION: MG132 induces apoptosis of leukemic cells, and effectively inhibits the NF-kappaB activation accompanied by the downregulation of survivin expression.

[Significance of CD4+ CD25+ CD127(low) regulatory T cells and notch1 pathway in the pathogenesis of aplastic anemia].

OBJECTIVE: To quantify the CD4+ CD25+ CD127(low) regulatory T cell (Treg), the expression levels of forkhead/winged helix transcription factor FOXP3 and Notch1 mRNA in aplastic anemia (AA) patients before and after treatment, and explore the significance of Treg in pathogenesis of AA. METHOD: CD4+ CD25+ and CD4+ CD25+ CD127(low) T cells in peripheral blood were examined with FACS in 29 AA patients at active phase, 14 at recovery phase, 11 at unrecovery phase, and 15 normal controls. The levels of FOXP3 mRNA and Notch1 mRNA expression were detected with RT-PCR, and the correlations between Treg, FOXP3 mRNA and Notchl mRNA were analyzed. RESULTS: The percentages of peripheral activated CD4+ CD25+ T cells in AA patients at active phase (4.3 +/- 0.7)% and unrecovery phase (4.2 +/- 0.6)% were significantly higher than those in normal controls (2.4 +/- 0.8)% (P < 0.05). The proportion of these cells in AA patients at recovery phase was reduced to (2.6 +/- 0.7)% (P < 0.05), being no difference from that in control group. The number of CD4+ CD25+ CD127(low) T cells in AA patients at active phase (2.4 +/- 1.2)% and unrecovery phase (2.5 +/- 1.1)% was decreased significantly compared with those in normal controls (7.1 +/- 2.7)% (P < 0.01) and in AA patients at recovery phase (5.3 +/- 1.0)% (P < 0.01), there was no difference between the latter two groups. In active phase AA patients, the levels of FOXP3 mRNA and Notchl mRNA (0.260 +/- 0.011 and 0.018 +/- 0.005, respectively) were lower than that in control group (1.307 +/- 0.011 and 0.308 +/- 0.028, respectively) (P < 0.01 and P < 0.01). After treatment, the levels significantly increased to 1.287 +/- 0.012 and 0.281 +/- 0.013 (P < 0.01 and P < 0.01), but there was no difference with that of normal controls (P > 0.05). CD4+ CD25+ CD2(low) T cells and FOXP3 were positively related with Notchl (P < 0.01) in AA patients. CONCLUSION: The decreased number and suppressive activity of CD4 CD25+ CD127(low) Treg cells in the peripheral blood of AA patients cause over-activation of autoreactive T cells and suppression of haematopoiesis. One of the mechanisms maybe the reduced expression of Notch1 in the target cells.