Σύγκριση μοριακών μεταβολών ανθρώπινων πολφικών κυττάρων σε μοντέλα στρες του ενδοπλασματικού δικτύου και αναπαραγωγικής γήρανσης

Postgraduate Thesis uoadl:1315370 550 Read counter

Unit:
Κατεύθυνση Βιολογία Στόματος (Βασικές Οδοντιατρικές Επιστήμες)
Βιβλιοθήκη Οδοντιατρικής
Deposit date:
2015-07-09
Year:
2015
Author:
Παναγιωτοπούλου Μαρία
Supervisors info:
Κιτράκη Ευθυμία, Βασταρδή Ελένη, Εμμανουήλ Δημήτριος
Original Title:
Σύγκριση μοριακών μεταβολών ανθρώπινων πολφικών κυττάρων σε μοντέλα στρες του ενδοπλασματικού δικτύου και αναπαραγωγικής γήρανσης
Languages:
Greek
Summary:
Εndoplasmic reticulum stress is a form of cellular stress, associated with
various disorders in humans. Although it has been widely studied in recent
years, its exact relationship with cellular (replicative) senescence has not
been elucidated. Specifically, the possible relationship between these two
systems has not been investigated at the protein level in human dental pulp
cells till recently.
The purpose of this study was to compare the responses of dental pulp cells
under induction of endoplasmic reticulum stress and replicative senescence at
the protein level. Primary cultures of human dental pulp cells from impacted
third molars were used for this purpose. The induction of endoplasmic reticulum
stress was performed by exposing the cells to tunicamycin, while replicative
senescence was achieved upon 20 successive passages. Cells’ viability after the
induction of stress was evaluated by using the MTT method. The confirmation of
cellular aging was done by detecting the senescence associated β-galactosidase
(SA β-gal)-positive cells and by observing the cells’ proliferative capacity.
The effects of tunicamycin on pulp cells were examined by determining the
levels of ERdj5 and TRX-1 proteins by Western blot. The effects of replicative
senescence were also examined by determining the levels of proteins ERdj5,
TRX-1 and DSP. The cellular responses to tunicamycin were evaluated after 4, 24
and 48 hours of exposure, while responses to replicative senescence were
evaluated in the 3rd, 8th, 12th, 16th and 20th passage.
The results demonstrated that tunicamycin was capable of inducing
endoplasmic reticulum stress in human dental pulp cells as it increased the
protein levels of ERdj5. Protein levels of the same molecule were reduced in
the model of replicative senescence. TRX-1 protein levels tended to decrease
after the induction of endoplasmic reticulum stress and to remain stable during
replicative senescence. Cellular aging was confirmed by the increasing number
of senescence associated β–galactosidase –positive cells and the reduced levels
of DSP with increasing passages.
In conclusion, pulp cells’ responses to endoplasmic reticulum stress and
replicative senescence are different concerning ERdj5 and TRX-1. Further study
is required to elucidate the relationship between these two models.
Keywords:
Endoplasmic reticulum stress, Pulp cells, Tunicamycin, ERdj5, TRX-1
Index:
No
Number of index pages:
0
Contains images:
Yes
Number of references:
45
Number of pages:
94
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