Human Keratinocyte-Derived Exosomal MALAT1 Promotes Diabetic Wound Healing by Upregulating MFGE8 via microRNA-1914-3p

Int J Nanomedicine. 2023 Feb 21:18:949-970. doi: 10.2147/IJN.S399785. eCollection 2023.

Abstract

Purpose: Diabetic wound is a highly prevalent and refractory disease. Extensive studies have confirmed that keratinocytes and macrophages play an important role in the process of wound healing. Additionally, exosomes are regarded as a vital intercellular communication tool. This study aimed to investigate the role of human keratinocyte-derived exosomal MALAT1 in the treatment of diabetic wound by influencing the biological function of macrophages.

Methods: We mainly assessed the function of MALAT1 on the biological changes of macrophages, and the expression of MALAT1 in the keratinocyte-exosomes analyzed by quantitative real-time polymerase chain reaction (RT-qPCR). The downstream interaction between RNAs or proteins was assessed by mechanistic experiments. Besides, we evaluated the effects of human keratinocyte-derived exosomal MALAT1 on diabetic wound healing in vivo to verify in vitro results.

Results: We demonstrated that human keratinocyte-derived exosomal MALAT1 enhanced the biological functions of high glucose-injured macrophages, including phagocytosis, converting to a pro-healing phenotype and reducing apoptosis. Mechanistically, MALAT1 accelerated the expression of MFGE8 by competitively binding to miR-1914-3p, thereby affecting the function of macrophages and the signal axis of TGFB1/SMAD3, and finally promoting the healing of diabetic wounds. Human keratinocyte-derived exosomal MALAT1 might promote collagen deposition, ECM remodeling, and expression of MFGE8, VEGF, and CD31 but reduce the expression of TGFB and SMAD3 in an in vivo model of diabetic mice wounds, which accelerated diabetic wound healing and restored its function.

Conclusion: The current study revealed that human keratinocyte-derived exosomal MALAT1 would suppress miR-1914-3p to activate MFGE8 and eventually promote wound healing by enhancing macrophage phagocytosis, converting to a pro-healing phenotype and reducing apoptosis. It proposed that keratinocyte-derived exosomes might have the capacity to serve as a new method for the clinical treatment of diabetic wound.

Keywords: MALAT1; diabetic wound healing; exosomes; keratinocytes; macrophages.

MeSH terms

  • Animals
  • Antigens, Surface
  • Diabetes Mellitus, Experimental*
  • Humans
  • Keratinocytes
  • Mice
  • MicroRNAs* / genetics
  • Milk Proteins
  • RNA, Long Noncoding* / genetics
  • Wound Healing

Substances

  • RNA, Long Noncoding
  • MicroRNAs
  • MFGE8 protein, human
  • Antigens, Surface
  • Milk Proteins
  • Mfge8 protein, mouse

Grants and funding

This study was supported by the young Scientists Fund of the National Science Foundation of China (81801922), Hubei Science and Technology Department of chronic wounds and diabetic foot medical clinical research center construction project(2018BCC340), Hubei Province Key R &D Project(2020BCB029) and Natural Science Foundation of Hubei Province (2020CFB696).