title: Substance P conjugated to CdTe quantum dots triggers cytosolic calcium concentration oscillations and induces quantum dots internalization in the pancreatic carcinoma cell line AR4-2J.
abstract: Highly fluorescent CdTe quantum dots (QDs) stabilized by 3-mercaptopropionic acid were prepared by an aqueous solution approach and used as a fluorescent label to link substance P (SP) in studying the interaction of SP with NK-1 receptor, which was expressed on the AR4-2J cell line. Nonspecific adsorptions of CdTe QDs on the AR4-2J cell membrane were observed, whereas the QD-SP conjugates successfully crossed the cell membrane and entered the cytosol. SP is a neurotransmitter, and neurotransmitter-induced calcium concentration oscillation is a common phenomenon in diverse cells especially of secretory type. Cytosolic calcium concentration responses were studied in the AR4-2J cell line during stimulation with SP and QD-SP conjugates. The oscillations triggered by SP and QD-SP conjugates were dose-dependent and very similar. Such QD-SP conjugates readily internalized into the cytosol as would be expected of an active NK-1 ligand. Therefore QD-SP conjugates could be used successfully to study ligand and NK-1 receptor interactions in live cells. Our research may provide a meaningful reference for congener research.
authors.affiliation: The College of Chemistry, Beijing Normal University, China.
authors.forename: Yu Jiao
authors.initials: YJ
authors.lastname: Duan
authors.forename: Hui Yuan
authors.initials: HY
authors.lastname: Liang
authors.forename: Wei Jun
authors.initials: WJ
authors.lastname: Jin
authors.forename: Zong Jie
authors.initials: ZJ
authors.lastname: Cui
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry*; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling; D045744:Cell Line, Tumor; D002463:Cell Membrane Permeability; D003600:Cytosol / Q000378:metabolism; D005456:Fluorescent Dyes / Q000737:chemistry; D006801:Humans; D018377:Neurotransmitter Agents / Q000378:metabolism*; D010179:Pancreas / Q000166:cytology / Q000378:metabolism; D045663:Quantum Dots; D018040:Receptors, Neurokinin-1 / Q000378:metabolism*; D013373:Substance P / Q000737:chemistry / Q000378:metabolism*; D013691:Tellurium / Q000737:chemistry*
chemical_list: D019187:Cadmium Compounds; D005456:Fluorescent Dyes; D018377:Neurotransmitter Agents; D018040:Receptors, Neurokinin-1; D013373:Substance P; D013691:Tellurium; C028337:cadmium telluride; D002118:Calcium