Isolation of Secretome with Enhanced Antifibrotic Properties from miR-214-Transfected Adipose-Derived Stem Cells

Delivery of Stem Cell Secretome for Therapeutic Applications

Intensive studies on stem cell therapy reveal that benefits of stem cells attribute to the paracrine effects. Hence, direct delivery of stem cell secretome to the injured site shows the comparative therapeutic efficacy of living cells while avoiding the potential limitations. However, conventional systemic administration of stem cell secretome often leads to rapid clearance in vivo. Therefore, a variety of different biomaterials are developed for sustained and controllable delivery of stem cell secretome to improve therapeutic efficiency. In this review, we first introduce current approaches for the preparation and characterization of stem cell secretome as well as strategies to improve their therapeutic efficacy and production. The up-to-date delivery platforms are also summarized, including nanoparticles, injectable hydrogels, microneedles, and scaffold patches. Meanwhile, we discuss the underlying therapeutic mechanism of stem cell secretome for the treatment of various diseases. In the end, future opportunities and challenges are proposed.

A novel strategy to promote liver regeneration: utilization of secretome obtained from survivin-overexpressing adipose-derived stem cells

Purpose

Survivin is a typical antiapoptotic protein. It is copiously expressed during human fetal development but is infrequently present in adult tissues. In this experiment, we researched the treatment effect of the secretome that adipose-derived stem cells (ASCs) transfected with survivin.

Methods

First of all, we generated survivin-overexpressing ASCs transfected with a plasmid comprising a gene encoding survivin. The secreted substances released from survivin-overexpressing ASCs (survivin-secretome) were collected, and were determined their in vitro and in vivo therapeutic potential, especially in the model of liver impairment.

Results

In vitro, the survivin-secretome significantly increased cell viability and promoted the expression of proliferation-related markers (proliferating cell nuclear antigen [PCNA], phospho-signal transducer and activator of transcription 3 (p-STAT3), hepatocyte growth factor [HGF], vascular endothelial growth factor [VEGF]) and anti-apoptosis-related markers (myeloid cell leukemia-1 [Mcl-1] and survivin) (P < 0.05). In vivo using 70% hepatectomy mice, the survivin-secretome group exhibited the lowest serum levels of interleukin-6, tumor necrosis factor-α (P < 0.05). The serum levels of liver transaminases (alanine aminotransferase and aspartate aminotransferase) were also the lowest in the survivin-secretome group (P < 0.05). The survivin-secretome group also exhibited the highest liver regeneration on the 7th day after 70% partial hepatectomy (P < 0.05). In the subsequent liver specimen analysis, the specimens of survivin-secretome exhibited the highest expression of p-STAT3, HGF, VEGF, PCNA, and Mcl-1 and the lowest expression of bcl-2-like protein 4 (P < 0.05).

Conclusion

Taken together, secretome secreted by survivin-overexpressing ASCs could be an effective way to improve liver regeneration and repair for liver injury treatment.