Large-scale phenotyping of an accurate genetic mouse model of JNCL identifies novel early pathology outside the central nervous system.
Cln3(Δex7/8) mice harbor the most common genetic defect causing juvenile neuronal ceroid lipofuscinosis (JNCL), an autosomal recessive disease involving seizures, visual, motor and cognitive decline, and premature death. Here, to more thoroughly investigate the manifestations of the common JNCL mutation, we performed a broad phenotyping study of Cln3(Δex7/8) mice. Homozygous Cln3(Δex7/8) mice, congenic on a C57BL/6N background, displayed subtle deficits in sensory and motor tasks at 10-14 weeks of age. Homozygous Cln3(Δex7/8) mice also displayed electroretinographic changes reflecting cone function deficits past 5 months of age and a progressive decline of retinal post-receptoral function. Metabolic analysis revealed increases in rectal body temperature and minimum oxygen consumption in 12-13 week old homozygous Cln3(Δex7/8) mice, which were also seen to a lesser extent in heterozygous Cln3(Δex7/8) mice. Heart weight was slightly increased at 20 weeks of age, but no significant differences were observed in cardiac function in young adults. In a comprehensive blood analysis at 15-16 weeks of age, serum ferritin concentrations, mean corpuscular volume of red blood cells (MCV), and reticulocyte counts were reproducibly increased in homozygous Cln3(Δ) (ex7/8) mice, and male homozygotes had a relative T-cell deficiency, suggesting alterations in hematopoiesis. Finally, consistent with findings in JNCL patients, vacuolated peripheral blood lymphocytes were observed in homozygous Cln3(Δ) (ex7/8) neonates, and to a greater extent in older animals. Early onset, severe vacuolation in clear cells of the epididymis of male homozygous Cln3(Δ) (ex7/8) mice was also observed. These data highlight additional organ systems in which to study CLN3 function, and early phenotypes have been established in homozygous Cln3(Δ) (ex7/8) mice that merit further study for JNCL biomarker development.
Molecular Neurogenetics Unit, Center for Human Genetic Research, Massachusetts General Hospital, Boston, Massachusetts, United States of America.
John F
JF
Staropoli
Larissa
L
Haliw
Sunita
S
Biswas
Lillian
L
Garrett
Sabine M
SM
Hölter
Lore
L
Becker
Sergej
S
Skosyrski
Patricia
P
Da Silva-Buttkus
Julia
J
Calzada-Wack
Frauke
F
Neff
Birgit
B
Rathkolb
Jan
J
Rozman
Anja
A
Schrewe
Thure
T
Adler
Oliver
O
Puk
Minxuan
M
Sun
Jack
J
Favor
Ildikó
I
Racz
Raffi
R
Bekeredjian
Dirk H
DH
Busch
Jochen
J
Graw
Martin
M
Klingenspor
Thomas
T
Klopstock
Eckhard
E
Wolf
Wolfgang
W
Wurst
Andreas
A
Zimmer
Edith
E
Lopez
Hayat
H
Harati
Eric
E
Hill
Daniela S
DS
Krause
Jolene
J
Guide
Ella
E
Dragileva
Evan
E
Gale
Vanessa C
VC
Wheeler
Rose-Mary
RM
Boustany
Diane E
DE
Brown
Sylvie
S
Breton
Klaus
K
Ruether
Valérie
V
Gailus-Durner
Helmut
H
Fuchs
Martin Hrabě
MH
de Angelis
Susan L
SL
Cotman
D000704:Analysis of Variance; D000818:Animals; D001831:Body Temperature; D001921:Brain / Q000473:pathology; D004195:Disease Models, Animal; D004596:Electroretinography; D005106:Exploratory Behavior / Q000502:physiology; D005260:Female; D005293:Ferritins / Q000097:blood; D005838:Genotype; D006321:Heart / Q000254:growth & development; D007150:Immunohistochemistry; D008214:Lymphocytes / Q000473:pathology; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism*; D009472:Neuronal Ceroid-Lipofuscinoses / Q000150:complications / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D009929:Organ Size; D010101:Oxygen Consumption / Q000502:physiology; D010641:Phenotype; D012162:Retinal Degeneration / Q000209:etiology / Q000473:pathology*
C102229:CLN3 protein, mouse; D008562:Membrane Glycoproteins; D018832:Molecular Chaperones; D005293:Ferritins