Post on 11-Jun-2015
description
A MOLECULAR AND GENETIC VIEW OF HUMAN
RENAL AND URINARY TRACT MALFORMATIONS
Adrian S WoolfNephro-Urology Unit
Institute of Child Health, University College London, UK
CLINICAL IMPORTANCE OF KIDNEY MALFORMATIONS
800 children in the UK have end stage renal failure. The commonest causes are: 1. Agenesis (absent kidney)2. Dysplasia (undifferentiated) 3. Hypoplasia (too few nephrons)
LOWER URINARY TRACT MALFORMATIONS
Kidney malformations are often associated with ureter and/or bladder malformations: 1. Vesicoureteric reflux2. Duplicated lower tracts3. Obstructed lower tracts
CAUSES OF KIDNEY AND LOWER URINARY TRACT
MALFORMATIONS1. Mutations of genes expressed during development2. Gross changes of fetal kidney milieue.g. impairment of fetal urine flow3. Subtle change of fetal kidney milieue.g. low protein maternal diet
PRIMARY VESICOURETERIC REFLUX
1. Occurs in 1% babies 2. ‘Reflux nephropathies’ can be congenital or acquired and account for 10% of end-stage renal failure2. Excess risk for vesicoureteric reflux in first degree relatives is x20-503. Some families have dominant inheritance 4. 1p13 locus and other undefined loci
VESICOURETERIC REFLUX
?II:1 II:2
I:2I:1
III:1 III:2 III:3 III:6III:5III:4 III:10III:9III:7 III:8 III:11 III:12 III:13III:15III:14
IV:1 IV:2
Embryonic urinary bladder Adult urinary bladder
Uroplakin Ib Uroplakin III
Vesicoureteric Reflux in the UK Establishing a DNA collection
www.vur.org.uk
DUPLEX KIDNEYS AND LOWER URINARY TRACTS
1. Occur in 1% of individuals2. Occurs with dysplastic kidneys and vesicoureteric reflux3. Excess risk in first degree relatives is about x20-30
FRASER SYNDROME1. Autosomal recessive - fused fingers,membrane across eyes and dysplasticor absent kidneys2. FRAS1 gene is mutated - protein coats the ureteric bud3. Null mutant mouse metanephrosinvolutes with excess apoptosis
Patient Described by George Fraser
Fraser Syndrome vs bl/bl Phenotype
Spectrum of Renal Defects in Fras1 targeted Mutants (b-d)
APOPTOTIC INVOLUTION OF CYSTIC
DYSPLASTIC KIDNEY
RENAL CYSTS AND DIABETES SYNDROME
1. Autosomal dominant or sporadic2. Renal agenesis, cysts, dysplasia, hypoplasia, with diabetes (can require insulin) and uterus malformations3. Hepatocyte Nuclear Factor 1βtranscription factor mutations
Single kidney
Q243fsdelC
Bicornuateuterus
Small kidneys
II
III
IV
Cystic renal dysplasia
1 2
21 3 4 5
1 2
NM NM
NM NM
I1 2
2
DUK507
HNF1β antisense HNF1β sensem
u
ORAL FACIAL DIGITAL SYNDROME TYPE 1
1. Male embryonic lethal – only affected females are born2. X-linked dominant 3. Glomerocystic kidney disease4. OFD1 gene codes for a centrosomal/basal body protein
OFD1Ab Preabsorbed OFD1 Ab
-120Danti ofd1
preabsorbed
EK84 EK75 EK73 EK70 WH
OLE
KID
NEY
v
OFD1 IMMUNOHISTOCHEMISTRY
ub
m
OFD1 PROTEIN IS EXPRESSED IN HUMAN EMBRYONIC KIDNEY MESENCHYME IN VIVO AND IN DERIVED CELL LINES
α-Tubulin mergeOFD1
C
150
100
75
37
25
50
OFD1 PROTEIN - GREENACETYLATED TUBULIN - RED
CAUSES OF KIDNEY AND LOWER URINARY TRACT
MALFORMATIONS1. Mutations of genes expressed during development2. Gross changes of fetal kidney milieue.g. impairment of fetal urine flow3. Subtle change of fetal kidney milieue.g. low protein maternal diet
ANIMAL MODEL OF POSTERIOR URETHRAL VALVESAND FETAL NEPHROPATHY AND UROPATHY
CAUSES OF KIDNEY AND LOWER URINARY TRACT
MALFORMATIONS1. Mutations of genes expressed during development2. Gross changes of fetal kidney milieue.g. impairment of fetal urine flow3. Subtle change of fetal kidney milieue.g. low protein maternal diet
THE EXPERIMENTAL MODEL
Pregnant rats were supplied isocaloricdiets in which the primary variable was the protein content from the day of conception to the end of pregnancy– 18% protein (control)– 9% protein (mild protein restriction)– 6% protein (severe protein restriction)Welham et al Kidney Int 61:1231-1242, 2002
Maternal lowprotein diet
Fewer nephrons
Elevated bloodpressure
Non-renalalterations
Ratembryonic
day 13
Embryonicday 15
Two weekspostnatal
Increasedmetanephric
apoptosis
Decreased cellnumber
Fewer nephronprogenitor cells
Adult
Embryonic kidney
Apoptosis
0
50
100
150
200
250
Series4Series5Series10A
popt
otic
cells
/mm
2P<0.01
P<0.05
Embryonic day 13
18% Protein
9% Protein
6% Protein
Glomerular complement of offspring at 2 weeks of age.
0
5000
10000
15000
20000
6% Protein 9% Protein 18% Protein
Glo
mer
uli * *
Systolic blood pressures of offspring at 4 weeks and 19 weeks of age.
050
100150200
4 weeks 19 weeks
Syst
olic
blo
od p
ress
ure
(mm
Hg)
.18% protein9% protein
* *
REPRESENTATIONAL DIFFERENCE ANALYSIS
• Genes ‘upregulated’ in metanephric kidneys exposed to maternal normal diet:
Cofilin-1, Prox-1, Calmodulin
• Genes ‘upregulated’ in metanephric kidneysexposed to maternal low protein diet:
Cadherin-11
CAUSES OF KIDNEY AND LOWER URINARY TRACT
MALFORMATIONS1. Mutations of genes expressed during development2. Gross changes of fetal kidney milieue.g. impairment of fetal urine flow3. Subtle change of fetal kidney milieue.g. low protein maternal diet
ACKNOWLEDGEMENTS FOR STUDIES OF KIDNEY AND URINARY TRACT MALFORMATIONS
University College London UKMonica Banerjee, Maria Bitner-Glindzicz, Isky Gordon,
Ambrose Gullett, Peter Cuckow, Chris Fry, Maggie Godley, Monika Hermanns, Mike Hubank, Maria Kolatsi-Joannou, Dagan Jenkins, Liam McCarthy,
Sue Malcolm, Peter Nyirady, Donald Peebles, Karen Price, Paul Riley, Leila Romio, Peter Scambler, Naima Smeulders, Niki Thiruchelvam,
Simon Welham, Melissa Whitten, Duncan Wilcox, Paul Winyard, Su-Ping YangElsewhere in UK
Coralie Bingham, Sally Feather, Andrew Fry, Judith Goodship, Tim Goodship, Andrew Hattersley, Albert Ong, Jenny Southgate, British Association for Paediatric Nephrology
Elsewhere in the worldTIGM Naples Italy - Brunella Franco and colleagues
NYU New York USA – Tung-Tien Sun and colleagues