Comparison of in vitro methods for carboxylesterase activity determination in immortalized cells representative of the intestine, liver and kidney.
Mol Cell Probes
; 29(4): 215-22, 2015 Aug.
Article
in En
| MEDLINE
| ID: mdl-25979594
ABSTRACT
Herein we compare the fluorimetric determination of total and specific carboxylesterase activity in immortalized human derived living cells and in cell lysates. The cell lines chosen are representative of metabolism occurring in the intestine (Caco-2 and HT-29), kidney (HEK-293T) and liver (Hep G2). Caco-2 and HT-29, as cells prone to differentiation, were tested along the differentiation time. For evaluation of both methods when distinguishing activity of different carboxylesterases, HEK-293T transfected with the human carboxylestarase-2 (hCES2) were also tested. Application to Caco-2 or HT-29 cells demonstrated higher activity detected in cell lysates than in cell monolayers. The difference is most striking when comparing the methods at different stages of Caco-2 and HT-29 cell maturation, highlighting substrate accessibility as a limiting step in the in vivo hydrolysis rates (possibly limited by plasma and Endoplasmic Reticulum membrane permeability) with increasing relevance as the cells differentiate. Application to Hep G2 or to hCES2 transfected and non-transfected HEK-293T cells, demonstrated a tendency for higher sensitivity in living cell suspensions than that obtained with the cell lysates which indicates the importance of cell environment in the maintenance of enzyme activity. However, quantification of hCES2 activity relative to total esterase, or to total carboxylesterase activity, was not significantly different in any case. The results herein presented help to clarify which method is best suited for evaluation of carboxylesterase activity in vitro depending on the final goal of the study.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Biochemistry
/
Carboxylic Ester Hydrolases
/
Intestines
/
Kidney
/
Liver
Type of study:
Evaluation_studies
Limits:
Humans
Language:
En
Journal:
Mol Cell Probes
Journal subject:
BIOLOGIA MOLECULAR
/
BIOTECNOLOGIA
Year:
2015
Type:
Article
Affiliation country:
Portugal