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IQGAP1 Mediates Hcp1-Promoted Escherichia coli Meningitis by Stimulating the MAPK Pathway

Mingna Zhao1, Lingfei Zhang2,3, Shaogang Lv1

  • 1Department of Laboratory Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong UniversityShanghai, China.

Frontiers in Cellular and Infection Microbiology
|May 5, 2017
PubMed

Insights

Hemolysin-coregulated protein 1 (Hcp1) from E. coli triggers brain cell death by upregulating IQGAP1, which activates the MAPK pathway. Inhibiting this pathway shows therapeutic potential for bacterial meningitis.

Area of Science:

  • Neuroscience
  • Microbiology
  • Cell Biology

Background:

  • Bacterial meningitis, particularly E. coli-induced, is a severe condition requiring new therapeutic strategies.
  • Understanding the molecular mechanisms of bacterial pathogenesis is crucial for developing effective treatments.

Purpose of the Study:

  • To investigate how hemolysin-coregulated protein 1 (Hcp1) induces apoptosis in human brain microvascular endothelial cells (HBMECs).
  • To identify downstream targets of Hcp1 and explore their role in meningitis pathogenesis.

Main Methods:

  • Co-immunoprecipitation and mass spectrometry were used to identify Hcp1-interacting proteins.
  • Western blotting and apoptosis assays were performed to analyze protein expression and cell death.
  • In vivo studies utilized a mouse model of E. coli meningitis.

Main Results:

  • IQ motif containing GTPase activating protein 1 (IQGAP1) was identified as a downstream target of Hcp1.
  • Hcp1 up-regulates IQGAP1, promoting HBMEC apoptosis by activating the MAPK/ERK1/2 signaling pathway.
  • The MAPK inhibitor U0126 demonstrated therapeutic efficacy in a mouse model of E. coli meningitis.

Conclusions:

  • Hcp1-induced HBMEC apoptosis is mediated by IQGAP1 and the MAPK signaling pathway.
  • Targeting the MAPK pathway represents a promising therapeutic strategy for bacterial meningitis.
Keywords:
Escherichia coliHCP1IQGAP1MAPK pathwaymeningitis

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