1. R14del-PLN in Cardiac Function
Litsa Kranias, Ph.D.
University of Cincinnati College of Medicine

2. What is PLN? PLN Is a Regulator of the Heart’s Pumping Action
Heart beats: ~70x/min or 100,000x per day
80ml or 1/3 cup per beat
When we run and exercise: there is a signal to the heart
to pump stronger and send more blood to periphery;
PLN plays a key role
Relax
Contract

3. PLN Regulates Calcium Cycling and Contractility in Cardiac Cells
channel 5 6 7 8
pCa RR
Pump
PLN
Myofillaments SR

4. R9C, R9L, R9H, R14del, R25C, L39stop, and V49G
Human PLN Mutations:
R9C, R9L, R9H, R14del, R25C, L39stop, and V49G R V I IB II L R R IB C II L V 4

5. Dead, no cardiomyopathy
2006: PLN-R14Deletion in a Greek Family I II
III IV
(+)
index V
(+)
(+)
(+)
(+) VI
(+)
VII
Dead, no cardiomyopathy
PLN-R14 Deletion
PLN-Normal
Dead, cardiomyopathy
+ Cardiomyopathy
Not determined

6. PLN-R14Del Mutation in a Subfamily PedigreeII I
III IV V
DCM
Dead, no cardiomyopathy
PLN-R14Del
Not tested
Dead, CM
PLN-Normal

7. Greek Patients with PLN-R14Del Mutation
10yrs-mid 30s yrs: asymptomatic, abnormal characteristic EKG
30yrs-on: heart failure symptoms, contractile dysfunction, ventricular arrhythmias
Arrhythmogenic RV cardiomyopathy and DCM for every Greek carrier
Netherlands: Van der Swaag et al., 2012

8. How Does R14del-PLN Cause Arrhythmias and HF?
Generate Animal Models to mimic the human disease
Humanized models: Roger’s team
WT-PLN
R14del-PLN

9. Isolate and study Right and Left Ventricular MyocytesRV LV
RV cells
LV cells RA LA RV LV
Oxygenated blood
Deoxygenated blood

10. R14del-PLN Inhibits Calcium Cycling in RV
NO effects in LV RV
R14del PLN A
Force or Ca Ca B Ca LV SR
SERCA
Time
A: Ca removal is slow; Relaxation and filling of RV is SLOW
B: Ca remains high; RV does not fully relax to fill in with blood
Time

11. R14del-PLN Binds and Inhibits SERCA more than
WT or Normal PLN (Athens Lab)
Calcium
Calcium
SERCA
SERCA
PLN
R14del
Force
Force
Time
Time

12. R14del-PLN Increases Ca2+ Sparks: Defects in Calcium CyclingWT
R14del
50 µm
1 s
Ca-sparks
Ca-sparks
RyR
RyR
WT-PLN
R14del PLN Ca Ca
SERCA
SERCA SR SR

13. R14del-PLN Induces Spontaneous Contractions
(indicative of Arrhythmias) 40 WT 30
Sponaneous Contractions
( % Cells)
R14del 20 10
R14del+KN93 RV
+KN93
CaMKII inhibitor KN-93 Inhibits Spontaneous Contractions

14. R14del-PLN Triggers Arrhythmias through Super-Inhibition
of SERCA and SR Ca-leak; KN-93 Inhibits Arrhythmias
3Na
3 Na
Arrhythmia Trigger Ca
KN93
Ca leak P
CaMKIIdc
RyR
R14del PLN Ca
SERCA Ca SR
1) R14del-PLN inhibits SERCA and this increases cytosolic Calcium 2) High Calcium activates CaMKII, which phosphorylates RyR 3) P-RyR leaks Calcium from SR and triggers arrhythmias

15. The Function of PLN and Mutant-PLN
SR Ca leak; Arrhythmias P
JNK
TRI
CamKII
JNK
RyR
RyR
TRI
CSQ
SERCA
CSQ
SERCA
PLN
R14del-PLN Ca Ca SR SR
WT-PLN
R14del-PLN

16. Two Steps in r14del-pln pathology:
Early: serca inhibition and calcium -leak
Late:aggregate formation
3Na
3 Na
Arrhythmias
Autophagy, Remodeling.
Lipid droplets Ca
Ca leak P
CaMKIIdc
RyR
SERCA Ca
R14del PLN: Aggregates SR
R14del PLN
ER Stress, Autophagy
Nucleus

17. The future looks bright
Many cardiovascular diseases have extended windows for
effective therapeutic treatments as the disease can take months
or even years to reach a level sufficient to produce symptoms.
This provides an opportunity to first model the particular disease,
test the most effective treatments in an animal model, and then
personalize a treatment that can be delivered at any stage, or even prophylactically before symptoms present.
J James and J Robbins, Circ Res 2016

18. Team Effort Towards Therapy
University of Cincinnati
Stanford University
The Mount Sinai Medical Center
The Netherlands Heart Institute
University of Gottingen
Biomedical Research Foundation Academy of Athens