molecular mechanisms of pediatric kidney disease nader gordjani md phd professor of pediatrics...
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Molecular Mechanisms of Pediatric Kidney Disease
Nader Gordjani MD PhDProfessor of Pediatrics
Universities of Freiburg and Frankfurt
Molecular origins of renal diseases
H2O
Hypophasphatemic rickets
Bartter-Syndrome
Hypokalemic alkalosis:
Gitelman-S.
Diabetes insipidus renalis
NEPHROTIC SYNDROME ?
CYSTÎC KIDNEYS ?
Lesions sites of the glomerulus
Filtration barrier
TH-Lypmphocytes
Capillaries
Mesangial cells
s. Biopsie
Deposits of antibodiesand complement
Podocyte
Autoantibodies
Nephrotic Syndrome
Nephritic Syndrome
kidney
Proteinuria > 40 mg/m2 * h
> 1000 mg/m2 * 24 h
Plasma Albumin < 25 g/l
Nephrotic Syndrome in Children
80% Steroid-sensitive
Stable function
20% Steroid-resistant
deterioration
Nephrotic Syndrome in Children
What is the role of the podocyte in nephrotic syndrome ?
Chemokines
cytokines
complement
autoantibodies
Inflammatoryagents
What is the role of the podocyte in nephrotic syndrome and as target of immunmodulation?
Chemokines
cytokines
complement
autoantibodies
Inflammatoryagents
Imm
unos
uppr
essi
on
Ca2+- Signalling in the cell
Stimulation of:
Signalling pathwaysGene expressionChannel opening/closing …
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0/3
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ATP 10-4 M
C a2+ 10-6 M
3 m in
Calcium signalling in the Podocyte
• Fluorescence microscopy with Fura-2 AM Single-Photon TubeVideo-ImagingLaser-Scanning
RT-PCR• Isolation of rat glomeruli by sieving method• Statistical analysis: student´s t-test
CCR
3
CCR
4
CCR
1
CCR
2
CCR
5
GAP
DH
334
605
409
563
410
334
500bp
CC-receptors of cultured mouse podocytes
chemokine receptor EC50 [ng/ml]
Rantes 1, 3, 5 50-700
TECK 4 300
Eotaxin 3 50
MIP-1 1, 5 20
MIP-1 5 100
MCP-1 2 10
MCP-2 2 200
MCP-3 1, 2 200
TARC 4 10
CXC
IL-8 1, 2 200
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2.0flu
ore
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atio
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0/3
80
ATP 100 µm ol/l
R AN TES 0.4 µg/m l
M C P-1 0.2 µg/m l
M IP-1 60 ng/m l
5 m in
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1.0flu
ores
cenc
e ra
tio 3
40 /
380
nm
400 700 1000
RANTES
ng / m l
(n=39) (n=11) (n=4)
R AN TES 0.7µg/m l
ATP 10-4M0.0
0.5
1.0
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2.5
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3.5flu
ores
cenc
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tio 3
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C a2+ 10-6 M
3 m in
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esce
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io 3
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80 n
m
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1.0
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1.4
f
luor
esc
ence
rat
io 3
40/
380
nm
(n=5) (n=8)
CyA
ATP A II
CyA
(n=6)
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0.2
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ore
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/38
0 n
m
RANTES 700 ng/m l
CyA 10 -5 M
Freshly isolated rat glomerulum
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4flu
ores
cenc
e ra
tio 3
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80 n
m
AC H 1 µm ol/l
M C P-1 20 ng/m l
10 m in
C YA 10 nm ol/l
R AN TES 70 ng/m l
ConclusionsChemokines induce an increase of [Ca2+]i in mouse podocytes by release from cytosolic Ca2+-stores and thus stimulate Ca2+-mediated signal transduction.
Therefore podocytes are target cells of these proinflammatory factors.
ATP also causes a characteristic rise of [Ca2+]i, which is mediated by Ca2+-influx from the extracellular space in addition to store release.
Cyclosporine A did not influence the chemokine- or ATP-associated Ca2+-effects.
These findings could partly be confirmed in podocytes from freshly isolated intact rat glomeruli.
Physiology
Andreas BenesicRuth FreudingerMichael GekleGerald Schwerdt
Pediatrics
Nader GordjaniAntje KirchhoffBrigitte Wollny
University of Würzburg
University of Freiburg
Physiologie
Rainer GregerHermann PavenstädtJens LeipzigerRoland NitschkeViktoria Munzinger
Hildebrandt F et al. JASN 2009;20:23-35
Ciliar defects: a unifying theory of cystic kidney disease?
Chapin et al. JCB 2010
Ciliar defects: a unifying theory of cystic kidney disease?
Hildebrandt F et al. JASN 2009;20:23-35
Correct mitotic spindle
orientation
False mitotic spindle
orientation