Τομέας Φυσιολογίας Ζώων και Ανθρώπου
Library of the School of Science

2013-03-21

2013

Τρυφωνίδη Ιουλία

Γαϊτανάκη Αικατερίνη Καθηγήτρια (Επιβλέπουσα), Παπαζαφείρη Παναγιώτα Αναπληρώτρια Καθηγήτρια, Βασιλακοπούλου Δίδω Αναπληρώτρια Καθηγήτρια

Ο ρόλος του ασβεστίου στα επαγόμενα από διάφορες μορφές στρες σηματοδοτικά μονοπάτια σε καρδιακούς μυοβλάστες H9c2

Greek

Role of calcium in the signaling pathways induced by various forms of stress, using H9c2 cardiac myoblasts

The aim of this study is to elucidate the role of calcium in the signaling
pathways induced by various forms of stress, using the cardiac myoblasts of the
cell line H9c2. For this reason, we used the compounds phenylephrine and
isoproterenol, synthetic analogues of catecholamines that cause a-and
b-adrenergic stimulation, respectively. The experimental procedure included
Western Blot immunoassays against p-ERKs proteins in cell extracts and MTT
cytotoxicity assays using culture cardiac myoblasts of the cell line H9c2.
As the results revealed, Phenylephrine induces activation of ERKs in a dose-
dependent and time-dependent manner. This activation is the maximum possible
compared to that induced by phorbol ester (PMA) and is completely inhibited by
the specific ERKs inhibitor PD98059. Using the inhibitors of calcium pump type
L, Nifedipine and Verapamil we proved that calcium ions from the extracellular
space are also involved in the activation of ERKs, while the intracellular
chelator BAPTA-AM did not affect the induced by phenylephrine phosphorylation
of ERKs.
As in a- so in b-adrenergic stimulation, isoproterenol induces the
phosphorylation of ERKs in a dose-dependent and time-dependent manner. The
phosphorylation appears to be inhibited by the inhibitor of calcium channel
type L Verapamil, minimally affected by the inhibitor of calcium channel type L
Nifedipine, and is not affected by the intracellular chelator BAPTA-AM. Then,
studying the long-term effects of isoproterenol, we found that the 24 hour
effect causes a time-dependent pattern of ERKs which produces a second maximum
at 16 hours post-application, increasing in parallel the cell viability. In
contrast, the 48 hours effect of isoproterenol caused cell death, which was not
affected by calcium blockers, but enhanced by the specific ERKs inhibitor
PD98059. All these results for the role of calcium in alpha-and beta-adrenergic
stimulation are really interesting and deserve further investigation.

Calcium, Nifedipine, Phenylephrine, Isoproterenol, Verapamil

No

0

Yes

177

viii, 93

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https://pergamos.lib.uoa.gr/uoa/dl/object/1319189