ABSTRACT
Hydrogen sulfide (H2S) that typically performs biphasic biological functions in organisms plays an opposite role at the concentrations above or below normal level of the organism. Therefore, it is significant to develop a fluorescent probe with high sensitivity and selectivity and rapid response for the detection of hydrogen sulfide in vivo. The work describes the design and biological applications of a novel turn-on fluorescence probe SS-N3 in which the quinoline quaternary ammonium salt derivative is introduced as the fluorescent skeleton and azide is employed as the detection group of H2S. The probe SS-N3 shows strong fluorescence at 610 nm, as the azide group is reduced to an amino group by H2S. The probe SS-N3 shows high selectivity to H2S than other anions and some biological mercaptans, and strong anti-interference capacity. In addition, the probe SS-N3 exhibits little cytotoxicity, improved photostability and large Stokes shift (135 nm), as well as can be effectively used as an indicator of H2S level in living cells.
Subject(s)
Ammonium Compounds , Hydrogen Sulfide , Quinolines , Azides , Fluorescent Dyes/toxicity , HeLa Cells , Humans , Microscopy, Fluorescence/methods , Optical Imaging , Sulfhydryl CompoundsABSTRACT
The cell membrane is composed of a phospholipid bilayer with embedded proteins and maintains cell homeostasis through dynamic changes. An abnormal cell membrane shape could be a sign of unhealthy cells. Probes for subcellular fluorescence imaging that can identify the abnormal plasma membrane and record the dynamic changes are needed. Based on a solvatochromic dye with a near-infrared emission strategy, the amphipathic molecule (E)-2,2'-((4-(2-(4-(dicyanomethylene)-4H-chromen-2-yl)vinyl)phenyl)azanediyl)bis(ethane-1-sulfonic acid) (MRL) contained a hydrophilic sulfo group and a hydrophobic chromone group, which was designed and synthesized for staining the cell membrane and monitoring the morphology of the membranes under different conditions. MRL exhibited an excellent photostability and low cytotoxicity; when cells were incubated with MRL, cell membranes were specifically labeled. MRL is capable of long-term monitoring of the morphological changes of cell membrane.
ABSTRACT
Satellite RNAs (satRNAs) are molecular parasites that interfere with the pathogenesis of the helper viruses. In this study, the relative accumulation of cucumber mosaic virus (CMV)-Fny genomic RNAs with or without satRNAs were quantitatively analyzed by real-time RT-PCR. The results showed that satRs apparently attenuated the symptoms of CMV-Fny on Nicotiana tabacum by depressing the accumulation of CMV-Fny genomic RNAs, tested as open reading frames. The accumulation of CMV-Fny 1a, 2a, 2b, 3a, and CP genes was much higher than that of CMV-Fny with satRs added (CMV-Fsat), at different inoculation times. CMV-FnyDelta2b, in which the complete 2b gene and 41 amino acids at the C-terminal of the 2a gene were deleted, caused only a slight mosaic effect on N. tabacum seedlings, similar to that of CMV-Fsat, but the addition of satRs to CMV-FnyDelta2b showed further decrease in the accumulation of CMV-FnyDelta2b genomic RNAs. Our results indicated that the attenuation of CMV, by adding satRs or deleting the 2b gene, was due to the low accumulation of CMV genomic RNAs, and that satRNA-mediated reduction of CMV genomic RNAs accumulation in N. tabacum was possibly related to the 2b gene.
