Hypocrellin-B acetate as a fluorogenic substrate for enzyme-assisted cell photosensitization

A. C. Croce, E. Fasani, M. G. Bottone, U. De Simone, G. Santin, C. Pellicciari, G. Bottiroli

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Photosensitizing molecules (PSs) undergo chemico-physical changes upon addition of suitable substituents, influencing both their photophysical properties and their ability to accumulate into cells. Once inside the cells, the modified PS acts as a fluorogenic substrate: the added substituent is removed by a specific enzyme, restoring the native PS in subcellular sensitive sites. We investigated the photophysical properties and interaction with HeLa cells of Hypocrellin-B (HypB), as native molecule and upon acetate-group addition (HypB-Ac). Chemical modification alters both absorption and fluorescence features of HypB; consequently, the dynamics of the enzyme hydrolysis of HypB-Ac can be monitored through restoring the native HypB spectral properties. At the cellular level, only the HypB emission signal was detected within 5 min of incubation with either HypB or HypB-Ac, allowing a direct comparison of the time courses of their intracellular accumulation. Plateau values were reached within 15 min of incubation with both compounds, the emission signals being significantly higher in HypB-Ac than in HypB treated cells. Consistently, imaging showed a rapid appearance of red fluorescence in the cytoplasm, with more abundant bright spots in HypB-Ac treated cells. Both compounds did not induce dark toxicity at concentrations up to 1 × 10 -6 M, while upon irradiation at 480 nm phototoxicity was significantly higher for cells exposed to HypB-Ac than for HypB-loaded cells. These findings suggest an improved efficacy of acetylated HypB to be internalized by cells through membrane trafficking, with a preferential interaction of the photoactive molecules on sensitive intracellular sites. After irradiation, in HypB-Ac treated cells, prominent disorganization of several cytoplasmic organelles such as the endoplasmic reticulum, Golgi apparatus, lysosomes, microfilaments and microtubules were observed.

Original languageEnglish
Pages (from-to)1783-1790
Number of pages8
JournalPhotochemical and Photobiological Sciences
Volume10
Issue number11
DOIs
Publication statusPublished - Nov 2011

Fingerprint

Fluorescent Dyes
enzymes
acetates
Enzymes
cells
molecules
Molecules
lysosomes
endoplasmic reticulum
fluorescence
organelles
irradiation
Cells
hypocrellin B acetate
hypocrellin B
cytoplasm
toxicity
hydrolysis
plateaus
Fluorescence

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

Cite this

Hypocrellin-B acetate as a fluorogenic substrate for enzyme-assisted cell photosensitization. / Croce, A. C.; Fasani, E.; Bottone, M. G.; De Simone, U.; Santin, G.; Pellicciari, C.; Bottiroli, G.

In: Photochemical and Photobiological Sciences, Vol. 10, No. 11, 11.2011, p. 1783-1790.

Research output: Contribution to journalArticle

Croce, A. C. ; Fasani, E. ; Bottone, M. G. ; De Simone, U. ; Santin, G. ; Pellicciari, C. ; Bottiroli, G. / Hypocrellin-B acetate as a fluorogenic substrate for enzyme-assisted cell photosensitization. In: Photochemical and Photobiological Sciences. 2011 ; Vol. 10, No. 11. pp. 1783-1790.
@article{b6087199bdea41f08d99ca1541762ac3,
title = "Hypocrellin-B acetate as a fluorogenic substrate for enzyme-assisted cell photosensitization",
abstract = "Photosensitizing molecules (PSs) undergo chemico-physical changes upon addition of suitable substituents, influencing both their photophysical properties and their ability to accumulate into cells. Once inside the cells, the modified PS acts as a fluorogenic substrate: the added substituent is removed by a specific enzyme, restoring the native PS in subcellular sensitive sites. We investigated the photophysical properties and interaction with HeLa cells of Hypocrellin-B (HypB), as native molecule and upon acetate-group addition (HypB-Ac). Chemical modification alters both absorption and fluorescence features of HypB; consequently, the dynamics of the enzyme hydrolysis of HypB-Ac can be monitored through restoring the native HypB spectral properties. At the cellular level, only the HypB emission signal was detected within 5 min of incubation with either HypB or HypB-Ac, allowing a direct comparison of the time courses of their intracellular accumulation. Plateau values were reached within 15 min of incubation with both compounds, the emission signals being significantly higher in HypB-Ac than in HypB treated cells. Consistently, imaging showed a rapid appearance of red fluorescence in the cytoplasm, with more abundant bright spots in HypB-Ac treated cells. Both compounds did not induce dark toxicity at concentrations up to 1 × 10 -6 M, while upon irradiation at 480 nm phototoxicity was significantly higher for cells exposed to HypB-Ac than for HypB-loaded cells. These findings suggest an improved efficacy of acetylated HypB to be internalized by cells through membrane trafficking, with a preferential interaction of the photoactive molecules on sensitive intracellular sites. After irradiation, in HypB-Ac treated cells, prominent disorganization of several cytoplasmic organelles such as the endoplasmic reticulum, Golgi apparatus, lysosomes, microfilaments and microtubules were observed.",
author = "Croce, {A. C.} and E. Fasani and Bottone, {M. G.} and {De Simone}, U. and G. Santin and C. Pellicciari and G. Bottiroli",
year = "2011",
month = "11",
doi = "10.1039/c1pp05136a",
language = "English",
volume = "10",
pages = "1783--1790",
journal = "Photochemical and Photobiological Sciences",
issn = "1474-905X",
publisher = "Royal Society of Chemistry",
number = "11",

}

TY - JOUR

T1 - Hypocrellin-B acetate as a fluorogenic substrate for enzyme-assisted cell photosensitization

AU - Croce, A. C.

AU - Fasani, E.

AU - Bottone, M. G.

AU - De Simone, U.

AU - Santin, G.

AU - Pellicciari, C.

AU - Bottiroli, G.

PY - 2011/11

Y1 - 2011/11

N2 - Photosensitizing molecules (PSs) undergo chemico-physical changes upon addition of suitable substituents, influencing both their photophysical properties and their ability to accumulate into cells. Once inside the cells, the modified PS acts as a fluorogenic substrate: the added substituent is removed by a specific enzyme, restoring the native PS in subcellular sensitive sites. We investigated the photophysical properties and interaction with HeLa cells of Hypocrellin-B (HypB), as native molecule and upon acetate-group addition (HypB-Ac). Chemical modification alters both absorption and fluorescence features of HypB; consequently, the dynamics of the enzyme hydrolysis of HypB-Ac can be monitored through restoring the native HypB spectral properties. At the cellular level, only the HypB emission signal was detected within 5 min of incubation with either HypB or HypB-Ac, allowing a direct comparison of the time courses of their intracellular accumulation. Plateau values were reached within 15 min of incubation with both compounds, the emission signals being significantly higher in HypB-Ac than in HypB treated cells. Consistently, imaging showed a rapid appearance of red fluorescence in the cytoplasm, with more abundant bright spots in HypB-Ac treated cells. Both compounds did not induce dark toxicity at concentrations up to 1 × 10 -6 M, while upon irradiation at 480 nm phototoxicity was significantly higher for cells exposed to HypB-Ac than for HypB-loaded cells. These findings suggest an improved efficacy of acetylated HypB to be internalized by cells through membrane trafficking, with a preferential interaction of the photoactive molecules on sensitive intracellular sites. After irradiation, in HypB-Ac treated cells, prominent disorganization of several cytoplasmic organelles such as the endoplasmic reticulum, Golgi apparatus, lysosomes, microfilaments and microtubules were observed.

AB - Photosensitizing molecules (PSs) undergo chemico-physical changes upon addition of suitable substituents, influencing both their photophysical properties and their ability to accumulate into cells. Once inside the cells, the modified PS acts as a fluorogenic substrate: the added substituent is removed by a specific enzyme, restoring the native PS in subcellular sensitive sites. We investigated the photophysical properties and interaction with HeLa cells of Hypocrellin-B (HypB), as native molecule and upon acetate-group addition (HypB-Ac). Chemical modification alters both absorption and fluorescence features of HypB; consequently, the dynamics of the enzyme hydrolysis of HypB-Ac can be monitored through restoring the native HypB spectral properties. At the cellular level, only the HypB emission signal was detected within 5 min of incubation with either HypB or HypB-Ac, allowing a direct comparison of the time courses of their intracellular accumulation. Plateau values were reached within 15 min of incubation with both compounds, the emission signals being significantly higher in HypB-Ac than in HypB treated cells. Consistently, imaging showed a rapid appearance of red fluorescence in the cytoplasm, with more abundant bright spots in HypB-Ac treated cells. Both compounds did not induce dark toxicity at concentrations up to 1 × 10 -6 M, while upon irradiation at 480 nm phototoxicity was significantly higher for cells exposed to HypB-Ac than for HypB-loaded cells. These findings suggest an improved efficacy of acetylated HypB to be internalized by cells through membrane trafficking, with a preferential interaction of the photoactive molecules on sensitive intracellular sites. After irradiation, in HypB-Ac treated cells, prominent disorganization of several cytoplasmic organelles such as the endoplasmic reticulum, Golgi apparatus, lysosomes, microfilaments and microtubules were observed.

UR - http://www.scopus.com/inward/record.url?scp=80455176468&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=80455176468&partnerID=8YFLogxK

U2 - 10.1039/c1pp05136a

DO - 10.1039/c1pp05136a

M3 - Article

C2 - 21894341

AN - SCOPUS:80455176468

VL - 10

SP - 1783

EP - 1790

JO - Photochemical and Photobiological Sciences

JF - Photochemical and Photobiological Sciences

SN - 1474-905X

IS - 11

ER -