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[J774A.1 cell apoptosis induced by Leptospira interrogans and effects of caspase-3, -6 activation on apoptosis]

Dan-dan Jin1, Hai-yan Dong, Jie Yan

  • 1Department of Microbiology and Parasitology, College of Medicine, Zhejiang University, Hangzhou 310058, China.

Zhejiang Da Xue Xue Bao. Yi Xue Ban = Journal of Zhejiang University. Medical Sciences
|December 17, 2008
PubMed
Abstract

Insights

Leptospira interrogans infection induces apoptosis in J774A.1 cells. This cell death is closely linked to the activation of intracellular caspase-3 and caspase-6 enzymes.

Area of Science:

  • Microbiology
  • Cell Biology
  • Immunology

Background:

  • Leptospira interrogans is a bacterial pathogen known to cause leptospirosis.
  • Apoptosis, or programmed cell death, is a critical cellular process.
  • J774A.1 cells are a commonly used murine macrophage cell line.

Purpose of the Study:

  • To investigate the induction of apoptosis in J774A.1 cells by Leptospira interrogans.
  • To determine the role of caspase-3 and caspase-6 activation in this process.

Main Methods:

  • Infection of J774A.1 cells with L. interrogans.
  • Assessment of apoptosis and necrosis using flow cytometry (FITC-Annexin V/PI).
  • Measurement of caspase-3 and -6 activity and their substrates (PARP, Lamin A/C) via fluorometry and Western Blotting.

Main Results:

  • L. interrogans induced apoptosis in J774A.1 cells, with a maximal apoptotic rate of 48.81% at a 100:1 microbe:cell ratio.
  • Maximal caspase-3 and -6 activities increased significantly (16.38- and 9.98-fold, respectively) in infected cells.
  • PARP and Lamin A/C cleavage was observed, and caspase inhibitors reduced L. interrogans-induced apoptosis.

Conclusions:

  • Leptospira interrogans effectively induces apoptosis in J774A.1 cells.
  • Intracellular caspase-3 and caspase-6 activation are integral to L. interrogans-mediated apoptosis in these cells.

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