Similar to Autophagy inhibition of immature oocytes during vitrification-warming and in vitro mature activates apoptosis via caspase-9 and 12 pathway (20)
2. INTRODUCTION
AUTOPHAGY
Controled digestion of damaged organells and
celular components, leaving behind
autophagosomes.
Function:
Housekeeping role (Damaged
organells).
Host defence mechanism (Kill infected
cells)
Cellular stress (nutrient deprivation)
APOPTOSIS
Death of cells that occurs as a normal and
controled part of the organism's growth and
development.
Function:
Limb Growth (Allows digit separation)
Nervous system (Death of cells who fail
to establish synaptic connections)
Inmune (Death of cells that aren't able
to produce antigen specificities)
5. OBJECTIVE
Determine the role of autophagy
in the immature oocytes during
vitrification-warming and in
vitro maturation.
6. MATHERIALS AND METHODS
Oocyte collection
➤ For Collection of CEOs a needle is introduced in the free
hilum pole of the ovary and the largest amount possible of
follicles are extracted.
➤ Cryopreservation
➤ IVF
Animals
➤ 50 female ICR mice
➤ 5-6 weeks of age
➤ Housed under ideal
conditions.
Oocyte vitrification
➤ Oocytes are submerged in
liquid nitrogen.
➤ Temperature of -196 °C.
➤ Fertility Preservation
➤ Oocyte donation
In Vitro Maturation
➤ CEOs are tranfered to microdrops of IVM medium in
Petri dishes and are stored at 37 °C.
➤ Pregnancy without ovarian stimulation
➤ IVF
7. Real Time PCR
➤ The detection of the acumulation of the
amplified products as they are generated in the
reaction.
➤ It’s like a regular PCR but with another
ingedient that is a single stranded DNA probe.
Quantify the viral load in the blood of
patients with HIV, Hepatitis B and other
viruses.
HIV is an RNA virus, but the RNA can be
quantified after it has been copied and
converted to a doble stranded DNA.
8. Western Blot
Separate proteins in a gel acording to their
molecular weight, then they’re transfered
to a membrane where they can be detected
using antibodies.
It’s used for verification of protein
production after cloning and protein
modification.
It can be used as a confirmatory test for
hepatitis B and herpes type 2 infection.
9. OF
Intracytoplasmatic sperm injection (ICSI)
➤ Procedure in whitch a single sperm is injected directly into the
cytoplasm of an oocyte.
➤ It’s used to prepare the gamets for the obtention of embyos that
can be tranfered to a maternal uterus or it can be for
cryopreservation.
10. Autophagy inhibitor; higher in group I
No significant change in any group
Loading control for integrity of the
cell and protein degradation
Higher in group I, where autophagy
was inhibited
RESULTS
12. DISCUSSION
AUTHOR CONCEPT ¿DO I AGREE?
Renzi L et al.
¨It is evident that cells exposed to low temperature
freezing would experience cellular damage caused by
osmotic and low-temperature stresses¨
Zhao N et al.
¨We have proved that oocyte cryopreservation is
associated with endoplasmic reticulum stress¨
Lu W et al.
¨We speculate that immature oocyte cryopreservation
causes ultra- structural alterations to organelles in oocytes
and the injury induces autophagy which is essential for the
cell survival by removal of damaged organelles.¨
Jones A et al.
¨The results indicate that autophagy inhibition of
immature oocytes during vitrification-warming and
IVM activates apoptosis via caspase-9 and 12
pathway.¨
13. OF
CONCLUSION
➤ For cryopreservation of oocytes autophagy cannot be inhibited if the
result needed are cells capable of fertilization.
➤ Vitrification – warming process and IVM induces cell stress that affects
important organells leading to autophagy.
