Abstract Objective To observe the qualitative and quantitative alterations of laminins in glomerular diseases, and to clarify their biological and pathological significance to evaluate the role in the pathotgensis. Method Five laminin chains (α1, α2, β1, β2 and γ1 ) were studied by immunohisto - chemistry and in situ hybridization. The qualitative and quantitative changes of distribution and mRNA expression were observed in 48 renal biopsy specimens from patients with glomerular diseases. Results The mRNA expressions of α1, α2, β1 and γ1 increased with different degrees in glomeruli associated with mesangial proliferation. These increases originated from proliferative mesangial cells. Increased expressions of α1 and γ1 proteins and abnormal expressions of α1 and β1 proteins were found in the segments with mesangial proliferation and glomerulosclerosis, whereas the expression of β2 decreased in the mesangium and GBM of the same lesions in various degrees. Conclusions Proliferative mesangial cells are the origins of abnormal accumulation and expression of laminins in the measngial proliferative glomeruli. The quantitative and qualitative alterations of laminin chains distribution were found in glomerular diseases. It may be the basis of the progression and deterioration of glomerular diseases.
