Adipose-derived stem cells (AT-MSCs) exhibit great potential for application in stem cell therapy, primarily due to their unique pro-regenerative capabilities, which include supporting skin regeneration. AT-MSCs secrete a variety of biomolecules with immunomodulatory, re-epithelializing, antifibrotic, antiapoptotic, proangiogenic, and neurotrophic activity as well as the ability to promote proliferation and migration of skin cells. Recently, therapy using AT-MSC secretome alone has garnered increasing attention due to its potentially safer and more effective application ability than the use of whole AT-MSCs. This review provides a comprehensive summary of the current state of knowledge regarding the potential use of AT-MSC secretome as a promising cell-free therapeutic strategy for wound healing, alopecia, skin rejuvenation, and skin inflammatory diseases. We critically analyze and discuss findings from in vitro, in vivo, and clinical studies. Moreover, we briefly discuss possible approaches to enhance the secretion of AT-MSC biomolecules, such as AT-MSC preconditioning with low-frequency electromagnetic fields and hypoxia. In conclusion, the evidence presented in this review paper underscores that the AT-MSC secretome alone can be a highly effective approach as a stem cell-free therapy for skin repair, with significant translational potential.

Circular RNAs (circRNAs) are noncoding molecules and are generated through back splicing, during which the 5′ and 3′ ends are covalently joined. Consequently, the lack of free ends makes them stable and resistant to exonucleases, and they become more suitable biomarkers than other noncoding RNAs. The aim of the study was to find an association between selected circRNAs and disease activity in patients with RA. A total of 71 subjects, 45 patients with RA and 26 healthy controls (HCs), were enrolled. In the RA group, 24 patients had high disease activity (DAS-28-ESR > 5.1) and 21 individuals were in remission (DAS-28-ESR ≤ 2.6). The cell line SW982 was used to evaluate the biological function of circ_0005567. The concentration of circ_0005567 in RA patients was elevated compared to HCs (median, 177.5 [lower–upper quartile, 83.13–234.6] vs. 97.83 [42.03–145.4], p = 0.017). Patients with high disease activity had a higher concentration of circ_0005567 than the control group (185.4 [112.72–249.25] vs. 97.83 [42.03–145.4], p = 0.015). In the cell line model, we found an association between circ_0005567 and miR-194-5p concentration and increased expression of mRNAs that may be related to cell proliferation. The plasma concentration of circ_0005567 may be a new potential biomarker associated with disease activity in patients with RA.