SECONDA CONFERENZA DEI PROGETTI DEL CENTRO FERMI

19-20 APRILE 2012

SALONE DELLE CONFERENZE DEL MINISTERO DELL’INTERNOROMA, PIAZZA DEL VIMINALE 1

In vitro-In vivo MUrine coSmiC siLEnce

experiment (MUSCLE)

D. Capece and E. Fratini (Centro Fermi)

on behalf of the Cosmic Silence Collaboration

Aim of MUSCLE Project

To understand the biological effects of environmental radiation

Peculiar low dose radiation effects (<100mGy)

Phenomenon in which unirradiated cells exhibit irradiated effects as a result of signals received from nearby irradiated cells.

Bystander effect

Genomic instability

Phenomenon characterized by an increase in the genetic spontaneous alteration observed in cells which have not themselves been irradiated, but are the progeny of an irradiated cell.

Peculiar low dose radiation effects (<100mGy)

Conditioning Dose Challenge Dose

Dam

ag

e +

Peculiar low dose radiation effects (<100mGy)

Adaptive reponse

Phenomenon that occurs when a low dose of mutagenic agent can protect from the biological damage of a subsequent high dose of the same or different mutagenica agents

Our Hypothesis

Life has evolved on Earth for 3 bilion years in the presence of

environmental ionizing radiation. All organism have therefore

incorporated in their normal biology a daily stiimulus of ultra-low-

dose environmental radiation that might act as conditioning agent.

LNGS – The Gran Sasso underground laboratory

Past Experiments

S. Cerevisiae cells

Chinese Hamster cells

Human cells

Satta et al., 1995.

Satta et al., 2002.Antonelli et al., 2008.

Carbone et al., 2009.Carbone & Pinto et al., 2010.

S. Cerevisiae D7 cells

Satta et al., Mutat. Res. 1995.

Chinese Hamster V79

Satta et al., Radiat. Environ. Biophys 2002.

Antonelli et al., Nuovo Cimento B 2008.

TK6 Lymphoblastoid cells

Carbone et al., Radiat. Environ. Biophys 2009.

Carbone & Pinto et al., Nuovo Cimento B 2010.

…Summarizing…

Compatible with our hypothesis of environmental radiation as a

conditioning agent, reduced environmental radiation conditions seem

to render cells, after several months of protracted culture:

Less tolerant to radiation-induced DNA damage

Less efficient in scavenging reactive oxygen species

pKZ1 Mouse Model

An ideal model for studying responses to very low doses of DNA

damaging agents

Matsuoka et al., Science 1991

LacZ Expression

Matsuoka et. al., Science 1991

pKZ1 Chromosomal Inversion Assay

P

P

DNA Inversion

ZcaL

LacZ

Experimental design

A11 Hybridoma cell line obtained from pKZ1 a splenocyte

Immortalized cell lines from brain and skin of neonatal pKZ1 mice

To use pKZ1 mouse chromosomal inversion assay to study

biological effects of environmental background radiation

Day et al., Radiat. Res. 1991

Experimental design

Istituto Superiore di Sanità Rome

LNGS - INFN

Reference environmental radiation (~ 2mGy/year)

Reduced environmental radiation (~ 25mGy/year)

Environmental Radiation

Compnents

ISS (External/Referenc

e Laboratory)

LNGS (Underground Laboratory)

Cosmic Rays 30 nGy/h Negligible

Cosmic and terrestrial g-rays

300 nGy/h 3.6 nGy/h

222Rn 1.7 nGy/h 0.17 nGy/h

Total dose rate ~ 330 nGy/h ~ 3.8 nGy/h

Experimental design

Rome Teramo

Inversion frequency

Doubling Time

Rate of apoptosis/autophagy

Redox cellular state

Biological End-points

ISS – Reference Environmental Radiation

LNGS – Reduced Environmental Radiation

Reference Environmental Radiation L’Aquila University

Reduced Environmental RadiationLNGS (L’Aquila)/LSC-Canfranc

underground laboratory (Saragozza)?

pKZ1 pKZ1

Perspectives

What happens in vivo?

INFNL. Satta

Istituto Superiore di SanitàG. Simone, M.A. Tabocchini

L’Aquila UniversityF. Zazzeroni, E. AlesseENEA Casaccia

R. Amendola

INFN-LNGSM. Balata

ENEAR. Amendola

Flinders University, AdelaideP. Sykes

Cosmic Silence Collaboration

CENTRO FERMID. Capece, E. Fratini, M.C. Carbone, M.

Pinto