PhD Scientific Days 2022

Molecular Sciences V.

Src-family Kinases in Immune-complex-mediated Glomerulonephritis

Text of the abstract

Introduction: Murine nephrotoxic nephritis is a widely used model of immune-complex-mediated glomerulonephritis. In this model, mice are immunized with normal sheep IgG, followed by administration of a sheep antiserum against mouse glomerular preparation (nephrotoxic serum; NTS). This leads to linear glomerular antibody deposition, severe glomerular inflammation and concomitant albuminuria and increased serum creatinine levels. The Src-family kinases Hck, Fgr, and Lyn are critical for various autoantibody-induced inflammatory disease models. These kinases are indispensable for the physiological effector functions of neutrophil granulocytes.
Aims: We used Hck−/−Fgr−/−Lyn−/− triple knockout mice to test whether these genes participate in the development of nephrotoxic nephritis.
Methods: Mice were preimmunized with sheep IgG followed by intravenous injection of NTS or normal sheep serum. Seven and fourteen days later urine was collected over a 24-hour period. Urinalysis was made for measuring the urine blood level. After fifteen day, blood was collected, the mice were perfused, the kidneys were removed, and the leukocyte infiltration and the glomerular injury was tested by flow cytometry and light microscopy. Frozen histological sections were made to test the antibody and the complement deposition.
Results: Wild type NTS-treated mice developed severe albuminuria and hematuria on the seventh and fourteenth day. In these animals’ kidney crescents were present in 10% of the glomeruli. Glomerulosclerosis and tubular injury could be also detected by light microscopy. Serum creatinine levels were more than two-times higher than in the control group, while serum albumin concentrations decreased due to the disease induction. In contrast, NTS-treated Hck−/−Fgr−/−Lyn−/− animals serum and urine parameters remained in the control range, with no substantial histological differences between the NTS-treated and the control group. However, antibody and complement deposition could be detected in both NTS-treated groups.
Conclusion: Our results indicate that Hck, Fgr, and Lyn have a crucial role in the development of immune complex-mediated glomerulonephritis.
Funding: EFOP-3.6.3-VEKOP-16-2017-00009