Neutrophil elastase reduces secretion of secretory leukoproteinase inhibitor (SLPI) by lung epithelial cells: role of charge of the proteinase-inhibitor complex
2008

Neutrophil elastase reduces secretion of secretory leukoproteinase inhibitor by lung epithelial cells

publication Evidence: moderate

Author Information

Author(s): Anita L Sullivan, Timothy Dafforn, Pieter S Hiemstra, Robert A Stockley

Primary Institution: University of Birmingham, UK

Hypothesis

The association of SLPI complexed with NE with cell membranes is the primary mechanism reducing SLPI concentration in cell culture supernatants.

Conclusion

The study suggests that the decrease in SLPI concentration due to NE is a passive, charge-dependent phenomenon.

Supporting Evidence

  • SLPI concentration decreased linearly with increasing NE concentration.
  • Direct contact between NE and SLPI was required for a fall in SLPI concentration.
  • Theoretical modeling showed a greater positive charge for the NE-SLPI complex compared to other proteinases.

Takeaway

When a protein called SLPI meets another protein called NE, SLPI gets stuck to cell surfaces and can't be found in the liquid around the cells anymore.

Methodology

Respiratory epithelial cells were cultured with varying doses of NE and other proteinases, and SLPI concentration was measured in the culture supernatants.

Potential Biases

Non-specific binding of SLPI to plastic components of the cell culture system may have influenced results.

Limitations

The study did not conclusively demonstrate that SLPI bound to cells in the presence of NE is biologically active.

Statistical Information

P-Value

0.006

Statistical Significance

p<0.05

Digital Object Identifier (DOI)

10.1186/1465-9921-9-60

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