MicroRNA-mediated calcineurin signaling activation induces CCL2, CCL3, CCL5, IL8, and chemotactic activities in 4,4′-methylene diphenyl diisocyanate exposed macrophages

Abstract

1. Occupational exposure to 4,4′-methylene diphenyl diisocyanate (MDI), the most widely used monomeric diisocyanate, is one of the leading causes of occupational asthma (OA). Previously, we identified microRNA (miR)-206-3p/miR-381-3p-mediated PPP3CA/calcineurin signalling regulated iNOS transcription in macrophages and bronchoalveolar lavage cells (BALCs) after acute MDI exposure; however, whether PPP3CA/calcineurin signalling participates in regulation of other asthma-associated mediators secreted by macrophages/BALCs after MDI exposure is unknown.

2. Several asthma-associated, macrophage-secreted mediator mRNAs from MDI exposed murine BALCs and MDI-glutathione (GSH) conjugate treated differentiated THP-1 macrophages were analysed using RT-qPCR.

3. Endogenous IL1B, TNF, CCL2, CCL3, CCL5, and TGFB1 were upregulated in MDI or MDI-GSH conjugate exposed BALCs and macrophages, respectively. Calcineurin inhibitor tacrolimus (FK506) attenuated the MDI-GSH conjugate-mediated induction of CCL2, CCL3, CCL5, and CXCL8/IL8 but not others. Transfection of either miR-inhibitor-206-3p or miR-inhibitor-381-3p in macrophages induced chemokine CCL2, CCL3, CCL5, and CXCL8 transcription, whereas FK506 attenuated the miR-inhibitor-206-3p or miR-inhibitor-381-3p-mediated effects. Finally, MDI-GSH conjugate treated macrophages showed increased chemotactic ability to various immune cells, which may be attenuated by FK506.

4. In conclusion, these results indicate that MDI exposure to macrophages/BALCs may recruit immune cells into the airway via induction of chemokines by miR-206-3p and miR-381-3p-mediated calcineurin signalling activation.

Keywords:

• 4,4′-methylene diphenyl diisocyanate (MDI)
• calcineurin
• macrophages
• immune cell chemotaxis
• microRNA (miR)

Disclosure statement

The authors declare that they have no conflicting financial interests. The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the National Institute for Occupational Safety and Health, Centres for Disease Control and Prevention.

Additional information

Funding

This work was supported by intramural funds (CAN#19390BN8) from the National Institute for Occupational Safety and Health, Centres for Disease Control and Prevention.