Microglia-Derived Exosomal microRNA-151-3p Enhances Functional Healing After Spinal Cord Injury by Attenuating Neuronal Apoptosis via Regulating the p53/p21/ CDK1 Signaling Pathway

1. Isabella Madrigal Álvarez
Third Semester
Universidad Pontificia
Bolivariana

2. • Spinal cord injury (SCI) is a central nervous traumatic
disease that can lead to neurological deficits.
• There are no fully restorative treatments for SCI.
• Creating an environment to protect neurons against
apoptosis is a novel therapeutic strategy to promote
biological repair and functional recovery after SCI.
• Microglia play a beneficial role in SCI repair.
INTRODUCTION

3. INTRODUCTION
• p53 is a protein that induces apoptosis when
there is a damage in DNA.
• p53 activates p21 transcription that inhibits
CDK1, which stimulates the cell to overstep
the G1 checkpoint.
• The effect of this signaling pathway is
attenuated by the microglia-Exos, so neuronal
apoptosis decreases.

4. Exosome
treatment promotes
neurological functional
recovery by
inhibiting neuronal
apoptosis and promoting
axon regrowth

5. METHODS
Immunofluorescence: Protein
determination by Ab binding to
a fluorochrome molecule
Fluorochrome-linked antibodies
are used to show the presence
of an antigen on cells.
Western blot: identify
specific proteins in a
complex mixture of proteins.
Protein is detected using an
antibody that is directed to
it.

6. METHODS
qRT – PCR: Amplifies and
simultaneously quantifies the
DNA amplification product.
TUNEL: Detects DNA fragmentation
by labeling the terminal fragment
of nucleic acids.

7. RESULTADOS
Microglía-Exos expresaron los marcadores exosomales
CD9, CD63, y Tsg101 en exosomas aislados
Exosomas podrían ser absorbidos por las neuronas.
Disminución en regeneración
del axón con restos de
mielina fue bloqueada por
los microglia-Exos

8. RESULTADOS
Apoptosis neuronal aumentó
con desechos de mielina.
Se atenuó con microglía - Exos
Aumenta expresión de p21 y p53,
proteínas apoptóticas (Bax y
caspasa-3 escindida), y
disminuyó la antiapoptótica Bcl2
PERO

9. AUTHOR POSTULATE AGREES?
Davalos et al
In the event of traumatic injury in the CNS, microglia are
the first cell type to rapidly respond and extend
cytoplasmic processes toward the lesion site to form a
protective barrier that limits neural tissue damage
Bellver-
Landete et al
In a mouse model of contusive SCI, microglia have also
been identified as a key cellular component for scar
formation that could protect neural tissue after SCI
Peng et al
Microglia-Exos exerted an antioxidant effect and could
promote endothelial cell survival and thus positively
modulate vascular regeneration and promote neurological
functional recovery post-SCI
DISCUSSION

10. CONCLUSIONS
• Methods and techniques of molecular biology are the bridge to
find causes and consequences of pathologies which affect
people's health. Molecular biology has lots of tests that help to
understand the evolution of a disease and contributes to its
diagnosis and treatment.
• Although it helps with the evolution of a disease, the most
important thing is that it influences the prevention of the
pathologies, because it helps to understand how a disease
works.

11. CONCEPTUAL
MAP

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¡THANKS!
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