Loss of Cx43-Mediated Functional Gap Junction Communication in Meningeal Fibroblasts Following Mouse Hepatitis Virus Infection
Mouse hepatitis virus (MHV) infection causes meningoencephalitis by disrupting the neuro-glial and glial-pial homeostasis. Recent studies suggest that MHV infection alters gap junction protein connexin 43 (Cx43)-mediated intercellular communication in brain and primary cultured astrocytes. In addition to astrocytes, meningeal fibroblasts also express high levels of Cx43. Fibroblasts in the meninges together with the basal lamina and the astrocyte endfeet forms the glial limitans superficialis as part of the blood–brain barrier (BBB). Alteration of glial-pial gap junction intercellular communication (GJIC) in MHV infection has the potential to affect the integrity of BBB. Till date, it is not known if viral infection can modulate Cx43 expression and function in cells of the brain meninges and thus affect BBB permeability. In the present study, we have investigated the effect of MHV infection on Cx43 localization and function in mouse brain meningeal cells and primary meningeal fibroblasts. Our results show that MHV infection reduces total Cx43 levels and causes its intracellular retention in the perinuclear compartments reducing its surface expression. Reduced trafficking of Cx43 to the cell surface in MHV-infected cells is associated with loss functional GJIC. Together, these data suggest that MHV infection can directly affect expression and cellular distribution of Cx43 resulting in loss of Cx43-mediated GJIC in meningeal fibroblasts, which may be associated with altered BBB function observed in acute infection.
KeywordsConnexin 43 Gap junction intercellular communication Primary meningeal fibroblast culture Mouse hepatitis virus (MHV) Intracranial infection Blood–brain barrier (BBB)
Authors thank IISER-K confocal facility and Mr. Ritabrata Ghosh for his technical assistance with microscopy.
This work is supported by research grants (BT/PR14260/MED/30/437/2010 and BT/PR4530/MED/30/715/2012 from Department of Biotechnology (DBT), India; RG3774A2/1 from National Multiple Sclerosis Society (NMSS), USA) and start up research fund from Indian Institute of Science Education and Research Kolkata (IISER-K), India, to JDS. AB is supported by IISER-K Integrated PhD program. RB is a recipient of senior research fellowship award from Council for Scientific and Industrial research (CSIR), India. MM is a recipient of Young Scientist award from Science and Engineering research Board (SERB), India.
Compliance with Ethical Standards
All animal experiments were performed following the approved guidelines of the Institutional Animal Ethical Committeee and Committee for the Purpose of Control and Supervision on Experiments on Animals (CPCSEA, India).
Conflict of Interest
The authors declare that they have no conflict of interest.
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