Fibroblast growth factor （FGF） receptor substrate 2a （FRS2α） is the main mediator of signaling in the FGF pathway. Recent studies have shown that mitogen-activated protein kinase （MAPK） phosphorylates serine an...Fibroblast growth factor （FGF） receptor substrate 2a （FRS2α） is the main mediator of signaling in the FGF pathway. Recent studies have shown that mitogen-activated protein kinase （MAPK） phosphorylates serine and threonine residues in FRS2, negatively affecting FGF-induced tyrosine phosphorylation （PY） of FRS2. Several kinds of stimuli can induce serine/threonine phosphorylation （PS/T） of FRS2, indicating that FRS2 may be useful for studying crosstalk between growth factor signaling pathways. Here, we report that FGF-induced PY of FRS2 can be attenuated by EGF co-stimulation in PC12cells; this inhibitory effect could be completely reversed by U0126, an inhibitor of MEK. We further identified the ERK1/2-binding motif in FRS2 and generated FRS2-3KL, a mutant lacking MAPK binding and PT upon FGF and/or EGF stimulation. Unlike wild-type （WT） FRS2, FGF-induced PY of FRS2-3KL could not be inhibited by EGF co-stimulation, and FRS2-3KL-expressing PC12 cells exhibited more differentiating potential than FRS2-WT-expressing cells in response to FGF treatment. These results suggest that PS/T of FRS2 mediated by the FRS2-MAPK negative regulatory loop may function as a molecular switch integrating negative regulatory signals from other pathways into FGFR-generated signal transduction.展开更多
Hydrogels constitute a group of polymeric materials which can hold a large amount of water in their three-dimensional networks due to their hydrophilic struc- tures. In the past few years, they have been researched fo...Hydrogels constitute a group of polymeric materials which can hold a large amount of water in their three-dimensional networks due to their hydrophilic struc- tures. In the past few years, they have been researched for various biomedical applications, such as drug/cell carriers, tissue engineering, and biosensors. Particularly, the hy- drogels used as drug delivery systems have shown distinct advantages in phototherapy. This review presents recent advancements of hydrogel＇s use in phototherapeutic applica- tions by focusing on three kinds of phototherapentic methods including photodynamic therapy （PDT）, photothermal therapy （PTT）, and phototherapy-containing combination therapy （PCCT）. The applications of these therapies in anti- cancer and antibacterial fields have also been summarized. We hope that this review will inspire researchers to further develop promising materials for phototherapy applications.展开更多
A convenient aptamer-based competitive electrochemical biosensor for a small biomolecule,adenosine,was described. The sensing surface was fabricated by self-assembly of an aptamer/mercaptohexanol monolayer on a gold d...A convenient aptamer-based competitive electrochemical biosensor for a small biomolecule,adenosine,was described. The sensing surface was fabricated by self-assembly of an aptamer/mercaptohexanol monolayer on a gold disk electrode. The principle of this aptasensor is based on the competition between an adenosine target molecule and a ferrocene-conjugated signaling DNA strand for the aptamer binding site on the sensing surface. Due to the competitive nature of this assay,the electrochemical responses of the surface captured ferrocene are inversely proportional to log[adenosine] in the range from 0.05 to 3.2 μM,with a detection limit of 25 nM. Moreover,the aptasensor also shows high selectivity for adenosine. The proposed aptasensor thus holds great potential for the detection of other small biomolecules.展开更多
文摘Fibroblast growth factor （FGF） receptor substrate 2a （FRS2α） is the main mediator of signaling in the FGF pathway. Recent studies have shown that mitogen-activated protein kinase （MAPK） phosphorylates serine and threonine residues in FRS2, negatively affecting FGF-induced tyrosine phosphorylation （PY） of FRS2. Several kinds of stimuli can induce serine/threonine phosphorylation （PS/T） of FRS2, indicating that FRS2 may be useful for studying crosstalk between growth factor signaling pathways. Here, we report that FGF-induced PY of FRS2 can be attenuated by EGF co-stimulation in PC12cells; this inhibitory effect could be completely reversed by U0126, an inhibitor of MEK. We further identified the ERK1/2-binding motif in FRS2 and generated FRS2-3KL, a mutant lacking MAPK binding and PT upon FGF and/or EGF stimulation. Unlike wild-type （WT） FRS2, FGF-induced PY of FRS2-3KL could not be inhibited by EGF co-stimulation, and FRS2-3KL-expressing PC12 cells exhibited more differentiating potential than FRS2-WT-expressing cells in response to FGF treatment. These results suggest that PS/T of FRS2 mediated by the FRS2-MAPK negative regulatory loop may function as a molecular switch integrating negative regulatory signals from other pathways into FGFR-generated signal transduction.
基金supported by the National Natural Science Foundation of China (21673037)Graduate Students’ Scientific Research Innovation Project of Jiangsu Province Ordinary University (SJLX16_0054)+2 种基金Fundamental Research Funds for the Central Universities (2242015R30016)Six Talents Peak Project in Jiangsu Province (2015-SWYY-003)Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry
文摘Hydrogels constitute a group of polymeric materials which can hold a large amount of water in their three-dimensional networks due to their hydrophilic struc- tures. In the past few years, they have been researched for various biomedical applications, such as drug/cell carriers, tissue engineering, and biosensors. Particularly, the hy- drogels used as drug delivery systems have shown distinct advantages in phototherapy. This review presents recent advancements of hydrogel＇s use in phototherapeutic applica- tions by focusing on three kinds of phototherapentic methods including photodynamic therapy （PDT）, photothermal therapy （PTT）, and phototherapy-containing combination therapy （PCCT）. The applications of these therapies in anti- cancer and antibacterial fields have also been summarized. We hope that this review will inspire researchers to further develop promising materials for phototherapy applications.
基金supported by the National Natural Science Foundation of China (20905062 & 20675064)research funds from Southwest Uni-versity (SWUB2008078 & XDJK2009B013)
文摘A convenient aptamer-based competitive electrochemical biosensor for a small biomolecule,adenosine,was described. The sensing surface was fabricated by self-assembly of an aptamer/mercaptohexanol monolayer on a gold disk electrode. The principle of this aptasensor is based on the competition between an adenosine target molecule and a ferrocene-conjugated signaling DNA strand for the aptamer binding site on the sensing surface. Due to the competitive nature of this assay,the electrochemical responses of the surface captured ferrocene are inversely proportional to log[adenosine] in the range from 0.05 to 3.2 μM,with a detection limit of 25 nM. Moreover,the aptasensor also shows high selectivity for adenosine. The proposed aptasensor thus holds great potential for the detection of other small biomolecules.
