Wilhelm bernhard workshop on the cell nucleus

MODULATION OF TRANSCRIPTION IN WCH-17 CELLS AFTER HYPOTERMIC STIMULUS

Vecchio L.¹, Baldelli B.², Malatesta M.² and Biggiogera M.<sup>1

1</sup>Dipartimento di Biologia Animale, Lab. Biologia Cellulare, University of Pavia, Pavia; ²Istituto di Istologia e Analisi di Laboratorio, University of Urbino “Carlo Bo”, Italy
DADLE ([D-Ala²-D-Leu⁵]-Enkephalin) is a meta-bolically stable analog of the endogenus δ opioid peptide enkephalin that may initiate its metabolic effects through specific membrane receptor. Since it is able to induce hibernation when injected in active ground squirrels, DADLE is supposed to mimic the action of the putative Hibernation Triggering Factor, i.e. a protein which is thought to drive vertebrates into hibernation. Recent data (Malatesta et al., 1999, 2001; Biggiogera and Pellicciari, 2000) show that, in different vertebrate tissues, RNP-containing structures undergo significant changes during hibernation. Moreover synthetic peptide can dramatically extend the organ survival time in multiorgan block preparation including lung, liver, heart and kidney. Consequently, we have hypothesized that DADLE could modulate both cell proliferation and transcription. The aim of the present investigation was to monitor the modifications in nuclear and nucleolar trascription after treating WCH-17 cells from a hibernating animal either at 4°C (hypotermia) with 10^-3M DADLE or only kept at 4°C, and finally incubated with 10mM BrU. The association of the peptide with hypotermic treatment seems to further affect transcription. When the cells are only kept at 4°C, BrU incorporation is present, although reduced in comparison with controls, while after DADLE treatment an accumulation of RNA as well as RNPs can be visualized in the nuclei.

Supported by a grant from MIUR (Cofin 2002 – grant n. 20022057484)

References:

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Malatesta M. et al., Anat Rec., 254: 389-95, 1999

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