Exosomes Derived from microRNA-21 Overexpressing Neural Progenitor Cells Prevent Hearing Loss from Ischemia-Reperfusion Injury in Mice via Inhibiting the Inflammatory Process in the Cochlea

Abstract

Both exosomes derived from neural progenitor cells (NPCs) can suppress inflammation. Whether exosomes derived from miR-21-transfected NPCs (miR-21-Exo) could be utilized to alleviate hearing loss is investigated. NPCs were transfected with lentiviral vectors overexpressing miR-21, and miR-21-Exo was purified. Morphology and exosome membrane markers were examined with nanoparticle tracking analysis, transmission electron microscopy, and Western blot. After incubation with different concentrations of miR-21-Exo, the viability of RAW 264.7 cells and the relative expressions of miR-21 and IL-10 were determined. The ischemia and reperfusion (I/R) model of C57BL/6 J mice was constructed, and the treatment benefit of miR-21-Exo was revealed by the auditory brainstem response (ABR) test. Immunofluorescence staining of caspase-3 and parvalbumin was used to detect apoptosis hair cells in the cochlea, and Western blot was utilized to detect the relative expressions of P53 and inflammatory cytokines in the cochlea. Isolated exosomes were confirmed by the size of 96 ± 25 nm, single membrane, and positive expression of CD9 and Tsg101. Upregulated miR-21 expression was detected in miR-21-transfected NPCs and miR-21-Exo. miR-21-Exo incubation demonstrated no cytotoxicity but upregulated miR-21 and IL-10 expressions in RAW 264.7 cells. The administration of miR-21-Exo inhibited the increased ABR threshold under 8, 16, and 32 kHz frequencies in cochlea-I/R injury mice and diminished the mean fluorescent intensity of caspase-3/parvalbumin. Moreover, miR-21-Exo treatment increased the IL-10 expression and prevented the increased TNF-α and IL-1β expressions in the cochlea of I/R mice both in mRNA and protein levels. Inner ear administration of miR-21-Exo effectively improved hearing damage caused by I/R.

Role and mechanism of FOXG1-related epigenetic modifications in cisplatin-induced hair cell damage

“…Because of the low transduction rate of adeno-associated virus in the cochlea, researchers have designed AAV-inner ear for gene delivery in the mouse cochlea and achieved a good therapeutic effect (Tan et al, 2019 ). RNase readily degrades miRNA in the plasma; thus, researchers have used exosomes produced by lentiviral overexpression of miR-21 as a carrier to deliver miR-21 to the inner ear, preventing hearing loss from ischemia-reperfusion (Hao et al, 2022 ). Injecting miR-375 agomir can alleviate nasal mucosa inflammation in allergic rhinitis mice (Wang et al, 2018 ).…”

Clinical applications of stem cell-derived exosomes

“…Hao et al discovered that exosomes derived from miR-21-overexpressing NSCs could prevent hearing loss from IRI by inhibiting the inflammatory process in the mouse cochlea. 306 This was evidenced by a reduced auditory brainstem response threshold, upregulated IL-10 and downregulated TNF-α and IL-1β.…”

“…In other words, some preclinical studies have not yet developed into clinical trials. These include, but are not limited to, exosome therapy for fracture 333 spinal cord injury 334 traumatic brain injury 335 acute liver injury 336 and hearing loss 304,306 which might serve as future directions for exosome therapy-related clinical trials.…”

The Role of Extracellular Vesicles in Diseases of the Ear, Nose, and Throat

“…However, proteomic analysis showed a significant increase in protein expression of Tmem 33, Pgm1, Eif3f, Rps24, Cct8, Hsd17b4, Aldh3a1, Ddost, Aldh3a1, Eif3c, Luc7l2, and Acadvl—proteins with known roles in hearing loss [ 99 ]. Using an ischemia and reperfusion model in C57BL/6 mice, a study by Hao et al discovered that delivery of NPC-EVs transfected with miR-21 to these mice reduced caspase-3/parvalbumin expression, increased IL-10 expression, and prevented an increase in TNF-α and IL-1β expression of cochlear hair cells [ 103 ]. This suggests that delivery of EV-miR-21 could serve to improve outcomes of cochlear damage related to ischemia [ 103 ].…”

“…Using an ischemia and reperfusion model in C57BL/6 mice, a study by Hao et al discovered that delivery of NPC-EVs transfected with miR-21 to these mice reduced caspase-3/parvalbumin expression, increased IL-10 expression, and prevented an increase in TNF-α and IL-1β expression of cochlear hair cells [ 103 ]. This suggests that delivery of EV-miR-21 could serve to improve outcomes of cochlear damage related to ischemia [ 103 ]. Another in vivo report found that, compared with normoxic bone marrow mesenchymal stem cells (BMSCs), hypoxic BMSCs reduced cisplatin-induced ototoxicity by upregulating HIF-1α, superoxide dismutase 1 (SOD1), and SOD2 expression [ 104 ].…”