Microscopical Investigation of the Efifect of Helminthosporol on Rice Seedlings

The elongation of the second leaf sheaths of rice seedlings was promoted strongly by helminthosporol as well as by gibberellic acid. A greater dosage of helminthosporol was required in order to induce the same amount of elongation. Cells of treated plants were somewhat longer than those of controls. The elongation of the second leaf sheath was caused mainly by an increase in cell number. Both helminthosporol and gibberellic acid promoted the elongation of cells in the basal portion of the second leaf sheath.     

Overexpression of B7-H1 (PD-L1) significantly associates with tumor grade and postoperative prognosis in human urothelial cancers

PURPOSE: The programmed death-1 (PD-1)/B7-H1 (also called PD-L1) pathway negatively regulates T cell activation and has been suggested to play an important role in regulating antitumor host immunity. To investigate the clinical significance of B7-H1 expression to the tumor grade and postoperative prognosis of patients with urothelial cancer, we analyzed the relationship between B7-H1 expression and various clinicopathological features and postoperative prognosis. EXPERIMENTAL DESIGN: Sixty-five urothelial cancer cases were examined. B7-H1 expression in tumors and the numbers and phenotypes of tumor-infiltrating lymphocytes were evaluated by immunohistochemistry and flow cytometry. RESULTS: A substantial expression of B7-H1 was observed in all urothelial cancers investigated. Tumor specimens from patients with higher WHO grade or primary tumor classifications showed significantly higher percentages of tumor-associated B7-H1. Tumor-associated B7-H1 expression was significantly associated with a high frequency of postoperative recurrence and poor survival rate. Furthermore, multivariate analysis indicated that tumor-associated B7-H1 was more significant prognostic factor than WHO grade. CONCLUSIONS: Our results demonstrate that the aberrant expression of B7-H1 in urothelial cancer is associated with aggressive tumors, suggesting a regulatory role of tumor-associated B7-H1 in antitumor immunity. Therefore, the manipulation of tumor-associated B7-H1 may become a beneficial target for immunotherapy in human urothelial cancer.     

The FBXL10/KDM2B Scaffolding Protein Associates with Novel Polycomb Repressive Complex-1 to Regulate Adipogenesis

Polycomb repressive complex 1 (PRC1) plays an essential role in the epigenetic repression of gene expression during development and cellular differentiation via multiple effector mechanisms, including ubiquitination of H2A and chromatin compaction. However, whether it regulates the stepwise progression of adipogenesis is unknown. Here, we show that FBXL10/KDM2B is an anti-adipogenic factor that is up-regulated during the early phase of 3T3-L1 preadipocyte differentiation and in adipose tissue in a diet-induced model of obesity. Interestingly, inhibition of adipogenesis does not require the JmjC demethylase domain of FBXL10, but it does require the F-box and leucine-rich repeat domains, which we show recruit a noncanonical polycomb repressive complex 1 (PRC1) containing RING1B, SKP1, PCGF1, and BCOR. Knockdown of either RING1B or SKP1 prevented FBXL10-mediated repression of 3T3-L1 preadipocyte differentiation indicating that PRC1 formation mediates the inhibitory effect of FBXL10 on adipogenesis. Using ChIP-seq, we show that FBXL10 recruits RING1B to key specific genomic loci surrounding the key cell cycle and the adipogenic genes Cdk1, Uhrf1, Pparg1, and Pparg2 to repress adipogenesis. These results suggest that FBXL10 represses adipogenesis by targeting a noncanonical PRC1 complex to repress key genes (e.g. Pparg) that control conversion of pluripotent cells into the adipogenic lineage.     

Severe hypercholesterolemia,impaired fat tolerance,and advanced atherosclerosis in mice lacking both low density lipoprotein receptor-related protein 5 and apolipoprotein E

LDL receptor-related protein 5 (LRP5) plays multiple roles, including embryonic development and bone accrual development. Recently, we demonstrated that LRP5 is also required for normal cholesterol metabolism and glucose-induced insulin secretion. To further define the role of LRP5 in the lipoprotein metabolism, we compared plasma lipoproteins in mice lacking LRP5, apolipoprotein E (apoE), or both (apoE;LRP5 double knockout). On a normal chow diet, the apoE;LRP5 double knockout mice (older than 4 months of age) had approximately 60% higher plasma cholesterol levels compared with the age-matched apoE knockout mice. In contrast, LRP5 deficiency alone had no significant effects on the plasma cholesterol levels. High performance liquid chromatography analysis of plasma lipoproteins revealed that cholesterol levels in the very low density lipoprotein and low density lipoprotein fractions were markedly increased in the apoE;LRP5 double knockout mice. There were no apparent differences in the pattern of apoproteins between the apoE knockout mice and the apoE;LRP5 double knockout mice. The plasma clearance of intragastrically loaded triglyceride was markedly impaired by LRP5 deficiency. The atherosclerotic lesions of the apoE;LRP5 double knockout mice aged 6 months were approximately 3-fold greater than those in the age-matched apoE-knockout mice. Furthermore, histological examination revealed highly advanced atherosclerosis, with remarkable accumulation of foam cells and destruction of the internal elastic lamina in the apoE;LRP5 double knockout mice. These data suggest that LRP5 mediates both apoE-dependent and apoE-independent catabolism of plasma lipoproteins.     

The Ionic Permeability Changes during Acetylcholine-Induced Responses of Aplysia Ganglion Cells

ACh-induced depolarization (D response) in D cells markedly decreases as the external Na⁺ is reduced. However, when Na⁺ is completely replaced with Mg⁺⁺, the D response remains unchanged. When Na⁺ is replaced with Tris(hydroxymethyl)aminomethane, the D response completely disappears, except for a slight decrease in membrane resistance. ACh-induced hyperpolarization (H response) in H cells is markedly depressed as the external Cl^- is reduced. Frequently, the reversal of the H response; i.e., depolarization, is observed during perfusion with Cl^--free media. In cells which show both D and H responses superimposed, it was possible to separate these responses from each other by perfusing the cells with either Na⁺-free or Cl^--free Ringer's solution. High [K⁺]₀ often caused a marked hyperpolarization in either D or H cells. This is due to the primary effect of high [K⁺]₀ on the presynaptic inhibitory fibers. The removal of this inhibitory afferent interference by applying Nembutal readily disclosed the predicted K⁺ depolarization. In perfusates containing normal [Na⁺]₀, the effects of Ca⁺⁺ and Mg⁺⁺ on the activities of postsynaptic membrane were minimal, supporting the current theory that the effects of these ions on the synaptic transmission are mainly presynaptic. The possible mechanism of the hyperpolarization produced by simultaneous perfusion with both high [K⁺]₀ and ACh in certain H cells is explained quantitatively under the assumption that ACh induces exclusively an increase in Cl^- permeability of the H membrane.