Effects of stem cell-derived exosomes on neuronal apoptosis and inflammatory cytokines in rats with cerebral ischemia-reperfusion injury via PI3K/AKT pathway-mediated mitochondrial apoptosis

Immunopharmacol Immunotoxicol. 2021 Dec;43(6):731-740. doi: 10.1080/08923973.2021.1976794. Epub 2021 Sep 22.

Abstract

Objective: This study aimed to investigate the effects of stem cell-derived exosomes (SC-Exos) on learning, memory, and neuronal apoptosis in rats with cerebral ischemia-reperfusion injury and to determine whether SC-Exos exert their effects via phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) pathway-mediated mitochondrial pathways of apoptosis.

Materials and methods: Eighty rats were randomly allocated to control, model, SC-Exos, and PI3K inhibitor groups. A model of focal cerebral ischemia-reperfusion was established using the improved Longa method. Expression of interleukin-1α (IL-1α), interleukin-2 (IL-2), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) were compared in the brains and serum of each group. The expressions of Bcl-2, Bax, cleaved-caspase-3, cleaved-caspase-9, cytochrome C (CytC), PI3K, and AKT-related genes and proteins were evaluated by real-time quantitative polymerase chain reaction and western blotting.

Results: The SC-Exos-group exhibited more novel entries, less latency for the novel arm, and fewer entries into the starting arm and other arms than the model group (p<.05). Lower expression of the inflammatory cytokines IL-1α, IL-2, and TNF-α and higher expression of IFN-γ were observed in the SC-Exos group than in the model group. TdT-mediated dUTP nick end labeling (TUNEL) assay showed that lower neural cell apoptosis rate and expression of Bax, cleaved-caspase-3, cleaved-caspase-9, CytC, PI3K, and AKT mRNA and proteins and higher expression of Bcl-2 mRNA and protein were observed in the SC-Exos group than in the model group (p<.05).

Conclusions: SC-Exos can significantly ameliorate brain injury caused by cerebral ischemia-reperfusion. The mechanism may be a novel therapeutic target for ischemia-reperfusion injury.

Keywords: Phosphatidylinositol-3-kinase/protein kinase B; inflammatory cytokine; neuronal apoptosis; novel therapeutic target; stem cell-derived exosome cerebral ischemia-reperfusion injury.

MeSH terms

  • Animals
  • Apoptosis / physiology
  • Brain Ischemia / metabolism*
  • Brain Ischemia / therapy
  • Cells, Cultured
  • Cytokines / antagonists & inhibitors
  • Cytokines / metabolism*
  • Exosomes / transplantation*
  • Humans
  • Inflammation Mediators / antagonists & inhibitors
  • Inflammation Mediators / metabolism
  • Male
  • Mitochondria / metabolism
  • Neurons / metabolism
  • Phosphatidylinositol 3-Kinases / metabolism*
  • Proto-Oncogene Proteins c-akt / antagonists & inhibitors
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Rats
  • Rats, Sprague-Dawley
  • Reperfusion Injury / metabolism*
  • Reperfusion Injury / therapy
  • Stem Cell Transplantation / methods*

Substances

  • Cytokines
  • Inflammation Mediators
  • Proto-Oncogene Proteins c-akt