The Distribution of Laminins
and mRNA
Expression In Normal and Pathologic Kidney
Huang S-M, Chen R-H, Guo M, et al
Nanjing Medical University, Nanjing, China
Objective: To observe the temporal
and spatial changes of expression of laminins in human developing kidneys, and
their alterations in glomerular diseases.
Methods: Three laminin chains (a2, b1 and b2) were examined by means of immunohistochemistry and in Situ
hybridization in 11 fetal, 3 normal adult kidneys and 34 renal biopsy
specimens from patients with mesangial proliferative glomerular nephritis.
Results: The protein of a2 chain was not found in all stages of kidney development Bui
its mRNA expressed in the kidney. b1
protein expressed in early stage of glomeruli and in the outside of the male
glomeruli. Whereas weak expression of b2 was seen in the earlier stage of glomeruli, and it increased
when the gomeruli underwent capillary loop expansion. It distributed in the
mature glomeruli only. Glomerular epithelial and mesangial cells in all stage
of kidney development could express b1 mRNA. Abnormal expression of a2 and bl
proteins were found in the segments with mesangial proliferation. Whereas
the expression of b2
decreased.The b1 mRNA expression
increased with different degrees in gomeruli associated with mesangial
proliferation. But no difference was detected among the degrees of
proliferation. These increases originated from the proliferated mesangial
cells.
Conclusion: There were temporal and spatial
changes of expression of laminin chains during development of human kidney.
The laminin chains distribution were altered in glomerular diseases. The
proliferated mesangial cells are the origins of the abnromal expression.