Anti-TRP polyclonal antibody

Cellular senescence has evolved as a protective mechanism to arrest growth of cells with oncogenic potential but is accompanied by the often pathologically deleterious senescence-associated secretory phenotype (SASP). Here we demonstrate an H2O2-dependent functional disruption controlling senescence-associated Ca(2+)homeostasis and the SASP. Senescent cells fail to respond to H2O2-dependent plasma lamellar Ca(2+)entry when compared to pre-senescent cells. Limiting exposure to senescence-associated H(2)O(2)restores H2O2-dependent Ca(2+)entry as well as transient receptor potential cation channel subfamily C member 6 (TRPC6) function. SA-TRPC6 and SASP expression is blocked by restoring Ca(2+)entry with the TRP channel antagonist SKF-96365 or by the mTOR inhibitors rapamycin and Ku0063794. Together, our findings provide compelling evidence that redox and mTOR-mediated regulation of Ca(2+)entry through TRPC6 modulates SASP gene expression and approaches which preserve normal Ca(2+)homeostasis may prove useful in disrupting SASP activity. Impact statement Through its ability to evoke responses from cells in a paracrine fashion, the senescence-associated secretory phenotype (SASP) has been linked to numerous age-associated disease pathologies including tumor invasion, cardiovascular dysfunction, neuroinflammation, osteoarthritis, and renal disease. Strategies which limit the amplitude and duration of SASP serve to delay age-related degenerative decline. Here we demonstrate that the SASP regulation is linked to shifts in intracellular Ca(2+)homeostasis and strategies which rescue redox-dependent calcium entry including enzymatic H(2)O(2)scavenging, TRP modulation, or mTOR inhibition block SASP and TRPC6 gene expression. As Ca(2+)is indispensable for secretion from both secretory and non-secretory cells, it is exciting to speculate that the expression of plasma lamellar TRP channels critical for the maintenance of intracellular Ca(2+)homeostasis may be coordinately regulated with the SASP.

Fluorescent stapled peptides are important chemical tools for detecting intracellular distribution, protein-protein interactions, and localization of target proteins. These peptides are usually labeled with bulky sized fluorophores through reactive functional groups, which may alter the physical properties and biological activities of peptides. Herein, a unique strategy is developed for synthesizing new stapled peptides with built-in fluorescence. The stapled peptides were prepared through Rh-catalyzed C(sp(2))-H olefination in tryptophan (Trp) residues by using pyridine/pyrimidine as the directing groups under mild conditions. This method displays good regioselectivity and high efficiency. Furthermore, as a proof of concept for its biological applications, stapled peptides without additional fluorophore 9 a and 9 b were constructed for a cell imaging study. These peptides displayed strong binding affinity toward integrin alpha v beta 3 in A549 cells by cell imaging experiments. Notably they demonstrated even better anticancer activity than commercial antagonist cyclic (RGDfK). The method will provide robust tools for the peptide macrocyclization field.