Crosstalk among miR‐29, α‐SMA, and TGFβ1/β3 in melatonin‐induced exosome (Mel‐prExo) treated human limbal mesenchymal stem cells (hLMSCs): An insight into scarless healing of the cornea

• Published in: BioFactors (Oxford) 2024-11, Vol.50 (6), p.1287-1297
• Main Authors: Altug, Burcugul, Soykan, Merve Nur, Eyubova, Sevinc, Eker Sariboyaci, Ayla, Dogan, Cezmi, Ozalp, Onur, Atalay, Eray
• Format: Article
• Language: English
• Subjects: Actins - genetics; Actins - metabolism; Cells, Cultured; cornea; Cornea - cytology; Cornea - drug effects; Cornea - metabolism; Exosomes - drug effects; Exosomes - genetics; Exosomes - metabolism; Gene Expression Regulation - drug effects; human limbal mesenchymal stem cell; Humans; Limbus Corneae - cytology; Limbus Corneae - metabolism; melatonin; Melatonin - pharmacology; Mesenchymal Stem Cells - drug effects; Mesenchymal Stem Cells - metabolism; MicroRNAs - genetics; MicroRNAs - metabolism; PPAR gamma - genetics; PPAR gamma - metabolism; programming exosome; scarless healing; Transforming Growth Factor beta1 - genetics; Transforming Growth Factor beta1 - metabolism; Transforming Growth Factor beta3 - genetics; Transforming Growth Factor beta3 - metabolism; Wound Healing - drug effects; Wound Healing - genetics
• ISSN: 0951-6433; 1872-8081; 1872-8081
• DOI: 10.1002/biof.2085

Inflammatory mediators that infiltrate the corneal stroma after corneal infections, trauma or refractive surgery can trigger the transformation of corneal keratocytes into myofibroblasts, resulting in highly irregular collagen deposition and subsequently corneal scarring. Mesenchymal stem cells (MSCs) can be used as therapeutic agents to regenerate corneal and conjunctival tissue damage, regulate inflammation, and reduce the development of limbal stem cell failure. The use of MSC‐derived exosomes as a cell‐free therapeutic vector is a novel therapeutic approach. This study aimed to assess the effect of exosomes obtained from melatonin (Mel)‐treated human limbal mesenchymal stem cells (hLMSCs) on naïve hLMSCs and to determine their influence on the antifibrotic and pro‐regenerative pathways involved in corneal scarring. hLMSCs were treated with varying concentrations of Mel, followed by isolation and characterization of the procured exosomes (Mel‐prExos). These exosomes were added to the cell culture media of naïve hLMSCs to examine their antifibrotic and pro‐regenerative effects. The expression of miR‐155, miR‐29, TGFβ1, TGFβ3, PPARγ, and α‐SMA miRNAs and genes were compared between Mel‐treated hLMSCs and Mel‐prExo‐treated hLMSCs by using real‐time PCR. We found that at 1 μM Mel and in the presence of Mel‐prExos, TGFβ1 was expressed 0.001‐fold, while TGFβ3 was expressed 0.6‐fold. miR‐29 expression was increased 38‐fold in the control‐Exo group compared to that in the control group. Changes in TGFβ1/β3 and α‐SMA expression are associated with miR‐29 and miR‐155. This approach could prove beneficial for ocular surface tissue engineering applications. Following the isolation and characterization of human limbal mesenchymal stem cells (hLMSCs), they were subjected to Mel treatment. Melatonin‐induced exosome (Mel‐prExo), derived from these Mel‐treated hLMSCs, was then generated. The impact of Mel‐prExo on cell proliferation and antifibrotic properties was assessed using the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay and real‐time PCR.