side effects: grundlagenforschung zur cni-nephrotoxizität
TRANSCRIPT
Side effects:
Grundlagenforschung zur CNI-Nephrotoxizität
S. Bachmann, Anatomie
DFG FOR 667
DFG FOR 1368
DFG SFB 1365
3 signals to rejection
TCR: Allopeptide on MHC of an APC reacts with TCR of a receptor TC
IL-2: Costimulating molecules of the APC bind to their TC counterpart
(CD80/86 to CD28); activation of CALCINEURIN PHOSPHATASE
->CBM-complex/NFkB, NFAT -> IL2
TC proliferation: IL2/IL2R binding -> mTOR, TC proliferation, clonal proliferation
-> TC mediated rejection
-> TC stimulate BC -> antibody-mediated rejection
B. Rudolph, 2018
C4d
Ca++ and calmodulin -> activation of Cn
Ca2+/Calmodulin-dependent S/T phosphatase
Heterodimer with catalytic subunit isoforms
CnB chain + CnAα, CnAβ, CnAγ
Inhibitors: Cyclosporine A and Tacrolimus/FK506
Immunophilins: (Cyclophilin A,B and FKBP12)
Calcineurin
Immunophilin bound to FK506
(Chaperone; cis/trans isomerase)
Since 1983: CNI
CsA,Tacrolimus,
Immunophilins
Williams & Gooch Exp Rev Mol Med 2012,
Kang CB Neurosignals 2008
CNI and immunophilins
CsA,Tacrolimus,
Immunophilins
Immunophilin
Chaperones
cis/trans Isomerase
Williams & Gooch Exp Rev Mol Med 2012,
Kang CB Neurosignals 2008
Calcineurin has multiple substrates!
CNI – side effects, nephrotoxicity - Pathology
CNI: Short term outcome very good, Risk: early application of high doses-> acute damage
CNI: Long term graft survival suboptimal
1. Functional/ acute arteriolopathy (hyalinosis; 92%)
2. Thrombotic microangiopathy
3. Toxic tubulopathy
4. Interstitial/striped fibrosis
5. Glomerulosclerosis; FGS, FSGS; proteinuria
Mihatsch 2011: CNI sind nephrotoxisch, aber es gibt keine
spezifischen histologischen Läsionen!
Terminus CAN = Chronic Allograft Nephropathy
CNI – side effects, acute nephrotoxicity: Pathology
Transplanted of own kidney:
Afferent constriction
Arteriolar vacuolization of muscular wall
A.A. thrombosis and loop collapse
Isometric tubular vacuolization (ER)
Thrombotic microangiopathy (rare)
Naesens 2018, Leal R et al., KI 2018
M. Thomson, IVA; Figs. a-c GSP
CNI – side effects, chronic nephrotoxicity: Pathology
Late-onset graft dysfunction (grades I to IV):
Arteriolar („beaded“) hyalinisation, subendothelial and media
Leal R et al., KI 2018
Vanhove T and Kuypers D, Transplantation 2017
Pathology – fibrosis and point of no return
Venk, Kriz, Bidani JASN 2015
Pathology: on the origin of fibrosis and its spreading upon AKI
Towards function: adverse effects of CNIs
Cyclosporine and tacrolimus may cause... • Hypertension
• Hyperkalemia
• Hypercalciuria
• Mild metabolic acidosis
• Calcium wasting
• ECM accumulation
• TGF-ß overproduction
• increased apoptosis
• elevated serum creatinine levels
CsA i.v. directly after transplantation: Switch fom diuresis to oliguria
"Between arteriolar constriction and renal scarring"
Morozumi & Mihatsch Transplant Proc 2004
CNI nephrotoxicity – structural vs. functional
View from 2004
Mortensen et al., FIM 2017
View from 2017
Eigene Arbeiten, Berlin
Treating rats, mice, zebrafish, cultured cells
with tacrolimus, CsA
Blankenstein et al. AJP 2017
J. Hu 2018
Juxtaglomerular apparatus
+CNI JG cells Renin
-CNI COX2 +CNI
A reason for COX-2
Höcherl et al. KI 2004
Daily Na excretion
mVal/d x kg b.w.
200
50
Basal Furosemide
Vehicle
Cyclosporine A
Rofecoxib
Cyclosporine A
+ rofecoxib
CsA likely attenuates the natriuretic action of loop diuretics
by inhibition of renal COX-2 expression
A reason for RAAS and CNI (rats, 35 d 15 mg CsA/kg)
Pichler RH… and Johnson R, JASN 1994
ACEI and ARBs – combined with CNI?
TGFß und endothelin levels decrease, creatinine clearance worsened
Unclear, whether co-treatment with ARBs is able to slow the progression of CNI
nephrotoxicity in a human setting
Long term studies: lisinopril and nifedipin have similar beneficial effects,
but also: nifedipin and not lisinopril improved graft function (Naesens)
Na-K-2Cl cotransporter NKCC2
Na-Cl cotransporter NCC
Renal salt handling, extracellular volume
and blood pressure control
Distal nephron and CNI-induced hypertension
CnA isoforms and cyclophilins distributed differentially
FKBP12
CyPA
K+
ROMK
Mg2+ Ca2+
NH4+
Blood
Na+
K+
Na,K-
ATPase
Calcineurin
Urine
P
P
P
Na+,K+,Cl-
Cl-
WNK
Ca2+
Ca2+
Ca2+
Ca2+
SPAK/
OSR1 P P
Cation-coupled chloride cotransporters: NKCC2
K+
ROMK
Mg2+ Ca2+
NH4+
Na+
K+
Na,K-
ATPase
Calcineurin
P
P
P
Cl-
WNK
Ca2+
SPAK/
OSR1 P P CnI Iph.
Na+,K+,Cl-
Blood
Urine
Cation-coupled chloride cotransporters: NKCC2
ΔIs
c,
μA
/cm
²
25µm
*
1
0
-200
-400
-600
-800
-1000
-1200
vehicle cyclosporine A
NKCC2
pT96/pT101-NKCC2
GAPDH
0
100
200
300
*
NKCC2 pNKCC2
CyA
vehicle
*
CyA + furosemide
vehicle + furosemide
GAPDH
pN
KC
C2
sig
na
l, %
isolated perfused TAL
Borschewski A K et al. J Am Soc Nephrol. 2015
Effects of cyclosporine A in rats: NKCC2 activity
0
2
4
6
8
0
20
40
60
80
100
120
140
Na e
xcre
tion
, m
M/k
g b
.w.
BP, m
m H
g
Salt retention Increased Blood Pressure
*
*
CyA
vehicle
10d CyA in rats
Effects of cyclosporine A in rats: volume aspects
CsA stimulates Na,K,2Cl-cotransport
Wu & Vandewalle KI 2000
86Rb+ influx,
nmol.min-1
.mg protein-1
Early findings
in subcultured
mouse mTAL
cells
Conclusion: TAL activated NaCl transport -
a component in CsA – induced hypertension
Bachmann S., Kidney Int 2018
Calcineurin and late distal tubule
Hypertension is salt-sensitive
Tac causes K retention
Hoorn E et al.
Nat Med 7:1304-9, 2011
Effects of tacrolimus in mice: animal physiology
Tac causes Hypertension
Tac increases pNCC Tac increases thiazide-
sensitivity
NCC ablation abrogates
Tac effects
Hoorn E et al.
Nat Med 7:1304-9, 2011
Tacrolimus activates NCC to cause hypertension
Conclusion: DCT activated NaCl transport -
a component in Tacrolimus – associated hypertension
Cn Cn
Calcineurin Inhibitors (cyclosporine A or tacrolimus)
Renal salt retention -> hypertension, electrolyte disorders
Controlling CNI hypertension with diuretics?
Since Schlöndorff et al. JASN 2008: 256 pubmed hits on UPR in the kidney!
SFB C04: Do CNI affect proteostasis (ER stress)?
7 Sites in the UPR for potential intervention
Design: Junda Hu, 2018
ER stress
UPR
Cytoprotective:
↑protein folding
↓protein translation
↑autophagy
Calcineurin Inhibitors
Maladaptive:
↑proapoptotic factors
Toxic tubulopathy 24% in CNI-NT: to study role of UPR
Lhotak AJP F 2012
Lab members and collaborators
Bachmann Lab
Good reviews in the field
are rare, this one is excellent, but needs update!
Naesens Nat Rev Nephrol 2016
CNI & immunosuppressant choice
Basic view in 2006: calcineurin function
Gooch j J, AJP F, 2006
IL-2 to -4 and TNFa
NATURE 1992
IL-2 - The original paper
Venk, Kriz, Bidani JASN 2015
Pathology: on the origin of fibrosis and its spreading upon AKI
CyA; Dr. Rudolph