title: Conjugated polythiophene probes target lysosome-related acidic vacuoles in cultured primary cells.
abstract: Conformation-sensitive optical probes for studying biological processes and structures are of great interest. The present work shows for the first time that conjugated polyelectrolyte (CPE) probes can be used for specific targeting of chromatin, nuclear and cytoplasmatic vesicles, and cytoskeletal components in a complex system of cultured cells. One of the probes could also be used for vital staining of live cells. When bound to different entities, the polythiophene derivative probes emitted light with different colors due to the unique spectral properties of these conformation sensitive probes. The physical pre-requisites for binding could also be exploited for characterization of the target. Unexpectedly, lysosome-related acidic vacuoles were targeted in cultured primary cells by both anionic, cationic, and zwitter-ionic polythiophene derivatives. Pre-treatment with Bafilomycin A1, a specific inhibitor of vacuolar-type H(+)-ATPase, caused redistribution of the staining. The targeting of lysosome-related acidic vesicles could not be demonstrated in transformed cells (melanoma, neuroblastoma, and prostate cancer cell lines), indicating a difference in the localization, structure, accessibility, or quantity of the target in cultured normal cells as compared with the malignant cell lines. The chemical nature of the conjugated polyelectrolyte complex in the cytoplasmatic vacuoles remains elusive.
authors.affiliation: Biomolecular and Organic Electronics, IFM, Linköping University, SE-581 83 Linköping, Sweden. perbj@ifm.liu.se
authors.forename: Per
authors.initials: P
authors.lastname: Björk
authors.forename: K
authors.initials: K
authors.lastname: Peter R Nilsson
authors.forename: Liselotte
authors.initials: L
authors.lastname: Lenner
authors.forename: Bertil
authors.initials: B
authors.lastname: Kågedal
authors.forename: Birgitta
authors.initials: B
authors.lastname: Persson
authors.forename: Olle
authors.initials: O
authors.lastname: Inganäs
authors.forename: Jon
authors.initials: J
authors.lastname: Jonasson
mesh_terms: D000818:Animals; D000838:Anions; D002412:Cations; D002470:Cell Survival / Q000187:drug effects; D002471:Cell Transformation, Neoplastic / Q000187:drug effects; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D008247:Lysosomes / Q000187:drug effects / Q000378:metabolism*; D018942:Macrolides / Q000494:pharmacology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008856:Microscopy, Fluorescence; D015335:Molecular Probes / Q000737:chemistry / Q000378:metabolism*; D009696:Nucleic Acids / Q000378:metabolism; D011108:Polymers / Q000737:chemistry / Q000378:metabolism*; D013876:Thiophenes / Q000737:chemistry / Q000378:metabolism*; D016707:Tissue Fixation; D014617:Vacuoles / Q000187:drug effects / Q000378:metabolism*
chemical_list: D000838:Anions; D002412:Cations; D018942:Macrolides; D015335:Molecular Probes; D009696:Nucleic Acids; D011108:Polymers; D013876:Thiophenes; C066730:polythiophene; C040929:bafilomycin A1