Synthesis And Application Of Fluorescence Probe For Detecting Intracellular Reactive Sulfur Species

There are various reactive endogenous species in vivo(proteins, small molecules and ions etc.). The intracellular reactive sulfur species(RSS) is a general term for sulfur-containing biomolecules, which belongs to reactive endogenous species. Such as glutathione(GSH), cysteine(Cys), and hydrogen sulfide(H2S) are all RSS. Sulfane sulfur are an uncharged form of sulfur(S0) with six valence electrons, which can be reversibly attached to proteins via covalent bond between S0 and other sulfur atoms.3,7 They are mainly presented in dihydropolysulfides(H-Sn-SH, n ≥ 1), hydropolysulfides(R-Sn-SH, n ≥ 1), polysulfides(R-S-Sn-S-R, n ≥ 1), and elemental sulfur(S8). These moleculars possess special physiological function, thus play a crucial impact on life processes. No matter in the normal cell organelles or in the same cell organelle under normal or disease states, the specious and concentration of these molecules are different. In recent years, hydrogen sulfide(H S) has been regard2 as the third endogenous gasotransmitter besides nitric oxide(NO) and carbon monoxide(CO). H S2 has been recognized to mediate a wide range of physiological and pathological processes in the cardiovascular and nervous systems of organism. However, many of the underlying biological mechanisms are still under research. Hydrogen polysulfides(H2Sn, n > 1) which are the direct redox form of H2 S, including the combination of polysulfur molecules. H2 Sn which possess the properties of antioxidant, cytoprotection, and redox signaling modulate many cellular functions through involving in an array of intracellular redox signaling processes. Moreover, more and more studies show that biological activities associated with H2 S may actually be mediated by H2 Sn which suggest that H2 Sn may be the actual signaling species, while H2 S may only play a role as a marker for the biologically active of H2 Sn species. Therefore, it is significant to elucidate the mechanism of signal transduction through detailed understanding of these active species produced under normal and disease states, distribution and physiological functions of the cells. However, due to the diversity and complexity of the organism environment, it is necessary to develop an analytical method with good selectivity and high sensitivity. Fluorescence bioimaging technology which is visualization-support plays a crucial role in the field of life analysis. Fluorescent probes offer a number of advantages, including real-time, noninvasive, sensitive and selective imaging dynamics changes of bioanalytes.basedonfluorescencebioimagingtechnology,wedesignthreeprobesforthedetectionofreactivesulfurspeciestoachievethefluorescenceimaging.theconcretecontentsareasfollows:(1)wehavedevelopedanewnirfluorescentprobemito-ssforevaluatingh2 snincellsaswellasinvivo.mito-ssemploysnitro-activatedfluorobenzoiateforh2 sntrappingandutilizesthelipophilictriphenylphosphoniumcationtosublocateinmitochondria.thefluorescentprobewhichmitochondria-targetedshowshighselectivityforh2 snoveravarietyofrss,rnsandros.weconfirmedthatboththeenzymecseandenzymecbsarecontributetogenerationofh2 sn.moreover,h2snalsocanbeproducedbyh2 sinpresenceofroscatalyzedbygpx.inaddition,mito-sscanbeusedformonitoringh2 snproductioninlivingcells,nomatterexogenouslyaddedorproducedviaenzymaticactivity.moreimportantly,theprobeisalsosuccessfullyutilizedtorealizeh2 snimaginginmice.(2)wepresentanewfluorescentprobebd-ssforspecifich2 sndetectionwithniremission.itexhibitsaturn-onfluorescenceresponseforh2 snoverotherreactiveoxygenspeciesandbiologicallyrelevantreactivesulfidespecies.theprobeemploysp-nitrofluorobenzoiateforh2 sntrapping.moreover,bd-sscanbeutilizedfortrackingh2 sninlivingcells.thecellsandmiceimagingestablishedtheprobeissuitableformonitoringh2sninbiologicalsystem.(3)wepresentanewfluorescentprobemito-sehforevaluatingsulfanesulfurincells.mito-sehemploys2-hydroselenobenzoicacidassulfanesulfurcapturegroupandthelipophilictriphenylphosphoniumcationformitochondria-targeted.whenexposedtosulfanesulfur,thefluorescentprobeexhibitshighselectiveturn-onfluorescenceresponsetosulfanesulfuroveravarietyofrss.inaddition,itsapplicabilityhasbeendemonstratedinfluorescenceimagingofsulfanesulfurinlivingcells,includingraw264.7cells,helacellsanda549 cells.moreimportantly,theprobeisalsosuccessfullyutilizedtorealizeh2 snimaginginmice.