Browsing by Author "Wang, Lingling"
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- Phytochemical Isoliquiritigenin Inhibits Angiogenesis Ex Vivo and Corneal Neovascularization in MiceWang, Lingling; He, Wenxiao; Qu, Huihua; Jia, Changkai; Wang, Yao; Wang, Yiqiang; Liu, Dongmin (Hilaris, 2014-11-21)Neovascularization is often involved in many diseases and there is no effective treatment for this pathological process. In searching for potential therapies for neovascularization, we screened nineteen pre-selected small molecules isolated from herbal extracts for their possible anti-angiogenic effect in vitro and in vivo. We found that isoliquiritigenin, a chalconoid compound isolated from Chinese herb medicine licorice, potently inhibited vascular endothelial cell (EC) proliferation, migration, tube -like structure formation ex vivo. Western blot analysis shows that exposure of ECs to isoliquiritigenin inhibited extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation. In Matrigel plug assay, isoliquiritigenin effectively blocked fibroblast growth factor-induced in vivo angiogenesis in mice. Consistently, topical application of isoliquiritigenin significantly inhibited chemical injury-induced corneal neovascularization in mice. Collectively, these results suggest that isoliquiritigenin may be a low-cost and effective natural agent to treat angiogenesis-dependent diseases.
- The type IV pilus assembly ATPase PilB functions as a signaling protein to regulate exopolysaccharide production in Myxococcus xanthusBlack, Wesley P.; Wang, Lingling; Jing, Xing; Saldaña, Rafael Castañeda; Li, Feng; Scharf, Birgit E.; Schubot, Florian D.; Yang, Zhaomin (Nature Publishing Group, 2017-08-04)Myxococcus xanthus possesses a form of surface motility powered by the retraction of the type IV pilus (T4P). Additionally, exopolysaccharide (EPS), the major constituent of bacterial biofilms, is required for this T4P-mediated motility in M. xanthus as the putative trigger of T4P retraction. The results here demonstrate that the T4P assembly ATPase PilB functions as an intermediary in the EPS regulatory pathway composed of the T4P upstream of the Dif signaling proteins in M. xanthus. A suppressor screen isolated a pilB mutation that restored EPS production to a T4P− mutant. An additional PilB mutant variant, which is deficient in ATP hydrolysis and T4P assembly, supports EPS production without the T4P, indicating PilB can regulate EPS production independently of its function in T4P assembly. Further analysis confirms that PilB functions downstream of the T4P filament but upstream of the Dif proteins. In vitro studies suggest that the nucleotide-free form of PilB assumes the active signaling conformation in EPS regulation. Since M. xanthus PilB possesses conserved motifs with high affinity for c-di-GMP binding, the findings here suggest that c-di-GMP can regulate both motility and biofilm formation through a single effector in this surface-motile bacterium.