Mesangial Deposition of Type I Collagen in Human Glomerulosclerosis ALAN
D.
AND
GLICK,
MD,
MICHAEL
A.
HARRY
R. JACOBSON,
HARALSON,
PHD
The presence of type 1 collagen in both diffuse and nodular glomerular
lesions
and electron banded
microscopic
collagen
of nodular
lesions.
in the fibrotic
interstitium
immediately anti-type
I collagen
of antibody
I collagen prise abetic type 1379.
antibody
lesion from
collagen is among
the sclerotic origin.
Copyright
obtained
glomerular
mesangial
using
These
lesions
with
to areas
staining
The pattern IV (basement
components
of both
diabetic
localization
origin. Saunders
HUM
with
in which
and focal scle-
anti-type
matrix
lesions ceil
and
in all cases
results demonstrate
the spatial by W.B.
localized
in the specimen.
the extracellular
1~ 1992
in glomeruli
fibrils
observed
in both the diabetic
that
were localized
cells. In cases of focal sclerosis
were
antibodies.
level,
in all cases
in all cases examined.
occurred
collagen
was presented
Furthermore,
suggest:s
antibodies
that type that comand nondi-
of this collagen
PATHOL
of‘ ;I rat model of glottlet-rr1osclerosi.s.“” Increased amounts of types IV, V, and VI I:ollagrn have heen reported in t~ietnhranoprolifer-ativ~ glomerulonephritis.” Of significance in these investigations was the finding of type III collagen in the tnesangium.’ This observation has been confirmed by studies from other laboratories indicating the presence of type III collagen in the ttiesangium in a variety of rrnal diseases.“,‘” However, onl!, the report of Funahiki rt A’” has indicated the presence of type I collagen in glomerular lesions. Furthermore, even though mesangial expansion has been correlated to loss of glomerular funt.tion in diabetes.“~7 no study examining ihe diabetic, lesions for type I collagen has been reported. The present study was undertaken to assess whethct. rvpe I collagen exists within sclerotic ksicms of hutnatt &meruli. Lesions of diabetic glomerulos~lerosis and focal glonierulosclerosis, prototypical examples of injury leading to ntesangial sclerosis. were chosen for exantination by electron microsc~opic and ittttnunoflttor~~s~~et~~e tnicroscopic techniques. in lesions
and in 60% of the diffuse
type I collagen
and was predominantly
banded
localization
differed
sclerosis against
to mesangial
origin,
the segmental
membrane)
capsules,
adjacent
of nondiabetic
At the ultrastructural in the mesangium
and the mesangium
with “ype I collagen
intact Bowman’s
rosis
techniques.
Antibodies
diabetic
using immunohistochemical
fibrils were observed
(Kimmelstiel-Wilson)
sclerotic Staining
has been examined
MD,
23:1373-
Company
(~lotttet~ttlo~c~lt~t-osis is a prominent feature in c,hronic renal dise;tse. (kll proliferation and the deposition ofinc reascd amounts and possibly different types 01’ extracellular matrix components characterize the histology olf the glomerulus in the end-stage hidney.‘.’ Extracellitl;tt- matrix changes occur both in the glomerular basement ntetnbratte and in the t~~esangiunt.“~7 The tiormal mesangium contains collagen types IV, V, and VI.‘,‘,” along with additional collagen types.‘” but does not contain the classic fiber-forming collagens. types 1 ;tncl I1 I. ’ H owevet.. mesangial cells in culture produce both collagen types I and III, with type I molecules king the predc;minant biosynthetic product.’ ‘-Ix This discrepancy between the collagenous components prescnt in the normal glomerulus and the collagen phenotype of mesangial cells in culture has led to the speculation that tiiesmgial cells in vitro express a profile of collagens itldicative of a wound-healing or sclerosing mt5angial cell in viva.“‘” Itntnutlohistochenti~al techniques have demonstrated type IV collagen in sclerotic lesions of human fiscal ~lotnet-ulosclerosis’!’ aInd types III and IV collagens
MATERIALS
AND METHODS
Patient Population I’i\sllr
sa~llples
l,iopiea
pert’ot-tltetl
Hoxpital
ant1
were
ol~lain~tl
for
diagnosis
Nashville Veterans
lv0111
at
Atfairs
Iwt~cut;ttieotts
Vanderl~ill Hospital.
reti:tl
Ilriiversit~ The
samples
included 25 casc~ of diabetic nephropath). I5 of which were tic)dular aloinei-lilos~lerosis and 10 of whic.h were clitfuse gloulei.~rlos~ler-osis. and L’X~‘ases oi idiopathic fcxxl @,tiicruloscle~x~sis occur-ring in both adrilts and children. All cases weir eValuatecl by light. rlec~tron. and iirlillllnolluio~~~s~~n~~ niicI’o~Cop\
Antibodies The I$ ,u+ainst either
fractions human
of
rabbit
polyclonal
type 1 collagen
antibodies
or hunlan
directed
t)‘pe IV collagen
were obtained
from DMI (Westbrook, MEj. The spet ifkit) of the antibc)dy preparation against human type I collagen was greater than 99.2% and the specificity of the antibody against hulnan t!pe IV collagen was greater than 99.8%. The specificities of these antibodies were established b) rhe manufacturcr.
Electron Microscopy Tissue fiixetl ill Y /c phosphate-hu~er-etl processed as pl-e\-iously clescribed.“’
lmmunofluorescence Fresll
glutaraldehycle
was
Microscopy
tisstle was embedded in O
D.
AND
GLICK,
MD,
MICHAEL
A.
HARRY
R. JACOBSON,
HARALSON,
PHD
The presence of type 1 collagen in both diffuse and nodular glomerular
lesions
and electron banded
microscopic
collagen
of nodular
lesions.
in the fibrotic
interstitium
immediately anti-type
I collagen
of antibody
I collagen prise abetic type 1379.
antibody
lesion from
collagen is among
the sclerotic origin.
Copyright
obtained
glomerular
mesangial
using
These
lesions
with
to areas
staining
The pattern IV (basement
components
of both
diabetic
localization
origin. Saunders
HUM
with
in which
and focal scle-
anti-type
matrix
lesions ceil
and
in all cases
results demonstrate
the spatial by W.B.
localized
in the specimen.
the extracellular
1~ 1992
in glomeruli
fibrils
observed
in both the diabetic
that
were localized
cells. In cases of focal sclerosis
were
antibodies.
level,
in all cases
in all cases examined.
occurred
collagen
was presented
Furthermore,
suggest:s
antibodies
that type that comand nondi-
of this collagen
PATHOL
of‘ ;I rat model of glottlet-rr1osclerosi.s.“” Increased amounts of types IV, V, and VI I:ollagrn have heen reported in t~ietnhranoprolifer-ativ~ glomerulonephritis.” Of significance in these investigations was the finding of type III collagen in the tnesangium.’ This observation has been confirmed by studies from other laboratories indicating the presence of type III collagen in the ttiesangium in a variety of rrnal diseases.“,‘” However, onl!, the report of Funahiki rt A’” has indicated the presence of type I collagen in glomerular lesions. Furthermore, even though mesangial expansion has been correlated to loss of glomerular funt.tion in diabetes.“~7 no study examining ihe diabetic, lesions for type I collagen has been reported. The present study was undertaken to assess whethct. rvpe I collagen exists within sclerotic ksicms of hutnatt &meruli. Lesions of diabetic glomerulos~lerosis and focal glonierulosclerosis, prototypical examples of injury leading to ntesangial sclerosis. were chosen for exantination by electron microsc~opic and ittttnunoflttor~~s~~et~~e tnicroscopic techniques. in lesions
and in 60% of the diffuse
type I collagen
and was predominantly
banded
localization
differed
sclerosis against
to mesangial
origin,
the segmental
membrane)
capsules,
adjacent
of nondiabetic
At the ultrastructural in the mesangium
and the mesangium
with “ype I collagen
intact Bowman’s
rosis
techniques.
Antibodies
diabetic
using immunohistochemical
fibrils were observed
(Kimmelstiel-Wilson)
sclerotic Staining
has been examined
MD,
23:1373-
Company
(~lotttet~ttlo~c~lt~t-osis is a prominent feature in c,hronic renal dise;tse. (kll proliferation and the deposition ofinc reascd amounts and possibly different types 01’ extracellular matrix components characterize the histology olf the glomerulus in the end-stage hidney.‘.’ Extracellitl;tt- matrix changes occur both in the glomerular basement ntetnbratte and in the t~~esangiunt.“~7 The tiormal mesangium contains collagen types IV, V, and VI.‘,‘,” along with additional collagen types.‘” but does not contain the classic fiber-forming collagens. types 1 ;tncl I1 I. ’ H owevet.. mesangial cells in culture produce both collagen types I and III, with type I molecules king the predc;minant biosynthetic product.’ ‘-Ix This discrepancy between the collagenous components prescnt in the normal glomerulus and the collagen phenotype of mesangial cells in culture has led to the speculation that tiiesmgial cells in vitro express a profile of collagens itldicative of a wound-healing or sclerosing mt5angial cell in viva.“‘” Itntnutlohistochenti~al techniques have demonstrated type IV collagen in sclerotic lesions of human fiscal ~lotnet-ulosclerosis’!’ aInd types III and IV collagens
MATERIALS
AND METHODS
Patient Population I’i\sllr
sa~llples
l,iopiea
pert’ot-tltetl
Hoxpital
ant1
were
ol~lain~tl
for
diagnosis
Nashville Veterans
lv0111
at
Atfairs
Iwt~cut;ttieotts
Vanderl~ill Hospital.
reti:tl
Ilriiversit~ The
samples
included 25 casc~ of diabetic nephropath). I5 of which were tic)dular aloinei-lilos~lerosis and 10 of whic.h were clitfuse gloulei.~rlos~ler-osis. and L’X~‘ases oi idiopathic fcxxl @,tiicruloscle~x~sis occur-ring in both adrilts and children. All cases weir eValuatecl by light. rlec~tron. and iirlillllnolluio~~~s~~n~~ niicI’o~Cop\
Antibodies The I$ ,u+ainst either
fractions human
of
rabbit
polyclonal
type 1 collagen
antibodies
or hunlan
directed
t)‘pe IV collagen
were obtained
from DMI (Westbrook, MEj. The spet ifkit) of the antibc)dy preparation against human type I collagen was greater than 99.2% and the specificity of the antibody against hulnan t!pe IV collagen was greater than 99.8%. The specificities of these antibodies were established b) rhe manufacturcr.
Electron Microscopy Tissue fiixetl ill Y /c phosphate-hu~er-etl processed as pl-e\-iously clescribed.“’
lmmunofluorescence Fresll
glutaraldehycle
was
Microscopy
tisstle was embedded in O
