Vitamin D receptor-deficient keratinocytes-derived exosomal miR-4505 promotes the macrophage polarization towards the M1 phenotype

PeerJ. 2023 Aug 4:11:e15798. doi: 10.7717/peerj.15798. eCollection 2023.

Abstract

Background: The vitamin D receptor (VDR) has a low level of expression in the keratinocytes of patients with psoriasis and plays a role in the development of the disease. Furthermore, the crosstalk between macrophages and psoriatic keratinocytes-derived exosomes is critical for psoriasis progression. However, the effects of VDR-deficient keratinocytes-derived exosomes (Exos-shVDR) on macrophages and their underlying mechanisms remain largely unknown.

Methods: VDR-deficient keratinocytes were constructed by infecting HaCaT cells with a VDR-targeting lentivirus, mimicking the VDR-deficient state observed in psoriatic keratinocytes. Exosomes were characterized using transmission electron microscopy, nanoparticle tracking analysis, and Western blot. The effect of Exos-shVDR on macrophage proliferation, apoptosis, and M1/M2 polarization was assessed using cell counting kit-8 assay (CCK-8), flow cytometer, real-time quantitative polymerasechain reaction (RT-qPCR), and enzyme-linked immunosorbent assay (ELISA). The mechanism underlying the effect of Exos-shVDR on macrophage function was elucidated through data mining, bioinformatics, RT-qPCR, and rescue experiments.

Results: Our results revealed that both Exos-shVDR and Exos-shNC exhibited typical exosome characteristics, including a hemispheroid shape with a concave side and particle size ranging from 50 to 100 nm. The levels of expression of VDR were significantly lower in Exos-shVDR than in Exos-shNC. Functional experiments demonstrated that Exos-shVDR significantly promoted macrophage proliferation and polarization towards the M1 phenotype while inhibiting macrophage apoptosis. Moreover, miR-4505 was highly expressed in the skin tissue of patients with psoriasis. Its overexpression significantly increased macrophage proliferation and polarization towards M1 and inhibited apoptosis. Furthermore, the effects of Exos-shVDR on macrophage function occur through miR-4505.

Conclusions: Exos-shVDR exacerbates macrophage proliferation, promotes polarization towards the M1 phenotype, and inhibits macrophage apoptosis by increasing the levels of miR-4505. These results indicate that modulation of macrophage function is a potential strategy for developing new drugs for the treatment of psoriasis.

Keywords: Exosomes; Macrophage polarization; MiR-4505; Psoriasis; VDR-deficient keratinocytes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • HaCaT Cells
  • Humans
  • Keratinocytes
  • Macrophage Activation*
  • MicroRNAs* / genetics
  • Psoriasis*
  • Receptors, Calcitriol* / genetics

Substances

  • MicroRNAs
  • Receptors, Calcitriol
  • MIRN4505 microRNA, human
  • VDR protein, human

Associated data

  • figshare/10.6084/m9.figshare.22705504.v1

Grants and funding

This work was funded by the Natural Science Foundation of Hubei (No. 2018CFB289), the Science Foundation of Health Commission of Hubei Province (No. WJ2019M074), the Science and Technology Planning Project of JingMen (No. 2020YFZD022); the Medical Scientific Research Foundation of Guangdong Province of China (No. A2022425); the Project of Administration of Traditional Chinese Medicine of Guangdong Province of China (No. 20221280); The Science Foundation of Health Commission of Hubei Province (No. W2023Q021) supported the APC. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.