Studying of regularity of programmed cell death after influence of demages factors

Speaker: Karolina Socha

2011 Student Practice in JINR Fields of Research Dubna, Russia

July 13 – 29, 2011

University of Wroclaw

Wroclaw Medical University

Our Group:

Laboratory of Radiation Biology (LRB)

JINR Group:Elena BaranovaMaria Saveleva

Student Group:Tatiana Alexandru (Romania)Karolina Socha (Poland)Katarzyna Shteklova (Czech Republic)

Joint Institute for Nuclear Research

Supervisor: Ivanka Ravnachka

1. Introduction.2. Materials and methods.3. Results.

Outline:

Relation between LET (Linear Energy Transfer) and the action typeDirect action is predominant with high LET radiation, e.g. alpha particles and neutrons.

Indirect action

is predominant with low LET radiation, e.g. X and gamma rays.

1. Introduction Studying of regularity of programmed cell death after influence of demages factors

Types of radiation-induced lesions in DNA

Base damage

Single-strand breaks Double-strand breaks

1. Introduction Studying of regularity of programmed cell death after influence of demages factors

NeoplasticNeoplastictransformationtransformation

of a cellof a cell

ChromosomeChromosomeaberrationsaberrations

MutationsMutations

ApoptosisApoptosis

DNADNAdouble-stranddouble-strand

breakbreak

Studying regularities in the induction of apoptosis and DNA double-strand breaks as the main initiating events in apoptotic cell death after the action of radiations with different physical properties.

Consequences of DSB induction in the cell genome

1. Introduction Studying of regularity of programmed cell death after influence of demages factors

Figure 1. Major diffrences between apoptosis and necrosis.

NecrosisAccidental uncontrolled cell death

leads to lysis of cell, inflammatory

responses and serious health

problems.

Apoptosis

Programmed cell death

occurs normally during development

and aging and as a homeostatic

mechanism to maintain cell populations

in tissues; defense mechanism (immune

reactions or when sells demaged by

disease or noxious agents (Norbury and

Hickson, 2001).

Differences between necrosis and apoptosis1. Introduction Studying of regularity of programmed cell death after influence of demages factors

Materials and methods

Figure 2. Fluorescent microscope (Carl Zeiss).

1. Seperate lymphocytes from whole human blood.

2. Add Hydrogen Peroxide.

3. Do preparations stained with mix of dyes (ethidium bromide and arcidine orange).

4. Use fluorescent microscope for tracing morphological changes in preparations.

5. Master the morphological method of detecting various forms of cell death.

Studying of regularity of programmed cell death after influence of demages factors

Apoptosis visualizationClasification criteria:

1. Bright green cells (irregularly shaped nucleus with heterogeneously poited chromatin) → living cells

2. Green or red cells (intact chromatine structure) → necrotic cells

3. Green or red cells (characteristic nuclear morphology: a rounded nucleus with collapsed chromatin) → apoptotic cells

Figure 3. Different forms of cell death

Studying of regularity of programmed cell death after influence of demages factors2. Materials and methods

0

20

40

60 0

30

60

necrotic apoptosis living

%

Time (h)

H2O

2

0

24

480

30

60

necrotic apoptosis living

%

Time (h)

Control

Apoptotic cell induction after adding H2O2

Studying of regularity of programmed cell death after influence of demages factors

Results

0 1 2 3 4 5 6 7 8 9 100

20

40

60

80

Apo

ptot

ic c

ells

[%]

Dose [Gy]

-rays

Studying of regularity of programmed cell death after influence of demages factors3. Results

Apoptotic cell induction after iradiation

Thank you for attention!

Studying of regularity of programmed cell death after influence of demages factors