SEMINARIO DE BIOLOGIA MOLECULAR, SE ESTUDIO LA UPR Y LAS CINASAS JNK EN EJERCICIO AGUDO

1. 2024
MARIANA CHICA CORREA -TERCER SEMESTRE DE MEDICINA
UNIVERSIDAD PONTIFICIA BOLIVARIANA

2. The c-Jun N-terminal kinases (JNKs) are a group of mitogen-
activated protein kinases.
They activate the transcription factor AP-1 via phosphorylation of c-
Jun proteins.
They have cellular functions such as regulation of cell proliferation,
apoptosis, cell differentiation, cellular stress response, ETC.
KINASES(JNKS)

3. UPR DEFINITION FUNCTION
The UPRmt protein
is a mitochondrial
signaling pathway.
is activated in response
to the accumulation of
misfolded proteins in
mitochondria and has a
protective role under
conditions of cellular
stress.
MT

4. OBJETIVE
The mitochondrial unfolded protein response (UPRmt) is an
adaptive cellular response to stress to ensure mitochondrial
proteostasis and function. Here we explore the capacity of
physical exercise to induce UPRmt in the skeletal muscle.

5. M
A
T
E
R
I
A
L
S
M
E
T
H
O
D
S
RNA SEQUENCING IN VIVO PHARMACOLOGICAL
JNK INHIBITION
RNA sequencing is a laboratory method
used to know the exact order (sequence)
of the building blocks that make up all
the RNA molecules in a cell.
RNA sequencing is used to identify and quantify
the different types of RNA present in a sample.
The TruSeq Stranded mRNA Library Prep Kit
(Illumina) was used to prepare the libraries. RNA
sequencing was performed using HiSeq. 2500
The method of in vivo pharmacological inhibition of
JNK (c-Jun N-terminal protein kinase kinase
kinase) involves the use of chemical compounds
designed to block JNK activity in a biological
environment.
After acute physical exercise, the mice were
injected intraperitoneally with saline (control) or
SP600125, to inhibit JNK

6. M
A
T
E
R
I
A
L
S
M
E
T
H
O
D
S
WESTERN BLOT BIOINFORMATICS ANALYSIS
Western blotting is an analytical technique to
detect specific proteins in a sample. This method is
based on the separation of proteins by gel
electrophoresis, followed by their transfer to a
membrane for identification using specific
antibodies.
It was used to evaluate the presence of UPRmt or
kinases by western blotting.
Bioinformatics analysis is the process of applying
computational tools and statistical methods to
understand and extract information from
biological data, in particular genomic and
sequencing data.
This method was used to analyze skeletal muscle
UPRmt, gene expression and different phenotypes.

7. RESULTS
FIG 2.

8. RESULTS 1.
The western blot method showed that 2h after exercise the MTCO1 encoded protein
was rapidly stimulated.
the UPRmt marker (ClpP) increased 4h after exercise

9. RESULTS 2.
The treadmill running also
increased the protein content of
other UPRmt markers in the
skeletal muscle, including the
mitochondrial proteases, Lonp1
and Yme1L1, and chaperone
HSP60

10. RESULTS 3.
Acute exercise also increased
several ETC components, such as
ATP5A (CV), MTCO1 (CIV), UQCRC2
(CIII), SDHB (CII) and NDUFB8 (CI)
in skeletal muscle. These data
demonstrate that acutely,
swimming and treadmill exercise
protocols elicit UPRmt in skeletal
muscle at the genetic and protein
level.

11. RESULTS 4.
Gastrocnemius submitted to
chronic exercise had increased
protein contents of OXPHOS
compo- nents, MTCO1 (CIV),
UQCRC2 (CIII), SDHB (CII), and
NDUFB8 (CI)

12. RESULTS
FIG 4.

13. RESULTS 5.
we observed that acute treadmill running stimulated JNK
threonine phosphorylation (p54 and p46) and cJun
phosphorylation (serine 63) in muscle fibers. We observed
that the same acute exercise also stimulated UPRmt markers
in the muscle of female mice.

14. EGAN B.
Physical exercise has been associated
with various adaptations, which are
mediated by increased muscle
function, mitochondrial biogenesis,
and oxidative capacity
AGREED
SLAVIN MB
Active Transcription Factor 5 (ATF5)
plays a key role in the control of
UPRmt markers in skeletal muscle of
exercising mice.
AGREED
MEMME JM
ORNATSKY OI
skeletal muscle stimulated at low
frequency showed an increase in
mitochondrial biogenesis, UPR
activation and mitochondrial
chaperones and proteases.
AGREED
KYRIAKIS JM
exercise increased JNK
phosphorylation and ATF5 protein
content in skeletal muscle. In this
scenario, we determined the role of
the key cellular stress sensor, JNK
AGREED
D
I
S
C
U
S
S
I
O
N

15. From a clinical and molecular biology point of view, it can be
concluded that physical exercise is a powerful stimulus for
mitochondrial biogenesis and function. This effect is due to
the increased demands for oxygen and energy during exercise,
which triggers adaptations beneficial to health and
performance. These adaptations include changes in mRNA and
protein levels, which are fundamental to the metabolic
changes associated with physical training.
CONCLUSIONS

16. Exercise has also been associated with increased NAD levels
and sirtuin activity, especially SIRT1, which stimulate
mitochondrial biogenesis and enhance the ability of skeletal
muscle to produce ATP and exercise. However, despite these
positive adaptations, how UPRmt (Mitochondrial Misfolded
Protein-bound Response in Mitochondria) contributes to these
responses to exercise is not yet fully understood. Further
investigation of the role of UPRmt and its interactions with
physical activity-mediated molecular pathways is needed to
better understand the benefits of exercise for health and
physical performance.
CONCLUSIONS

18. Thank you!