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Exosomal miR-223 Contributes to Mesenchymal Stem Cell-Elicited Cardioprotection in Polymicrobial Sepsis.

Wang X, Gu H, Qin D, Yang L, Huang W, Essandoh K, Wang Y, Caldwell CC, Peng T, Zingarelli B, Fan GC - Sci Rep (2015)

Bottom Line: However, WT-MSCs were able to provide protection which was associated with exosome release.Conversely, WT-MSC-derived-exosomes displayed protective effects.By contrast, WT-exosomes encased higher levels of miR-223, which could be delivered to cardiomyocytes, resulting in down-regulation of Sema3A and Stat3.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacology and Cell Biophysics, University of Cincinnati College of Medicine, Cincinnati, OH, USA.

ABSTRACT
Mesenchymal stem cells (MSCs) have been shown to elicit cardio-protective effects in sepsis. However, the underlying mechanism remains obscure. While recent studies have indicated that miR-223 is highly enriched in MSC-derived exosomes, whether exosomal miR-223 contributes to MSC-mediated cardio-protection in sepsis is unknown. In this study, loss-of-function approach was utilized, and sepsis was induced by cecal ligation and puncture (CLP). We observed that injection of miR-223-KO MSCs at 1 h post-CLP did not confer protection against CLP-triggered cardiac dysfunction, apoptosis and inflammatory response. However, WT-MSCs were able to provide protection which was associated with exosome release. Next, treatment of CLP mice with exosomes released from miR-223-KO MSCs significantly exaggerated sepsis-induced injury. Conversely, WT-MSC-derived-exosomes displayed protective effects. Mechanistically, we identified that miR-223-KO exosomes contained higher levels of Sema3A and Stat3, two known targets of miR-223 (5p &3p), than WT-exosomes. Accordingly, these exosomal proteins were transferred to cardiomyocytes, leading to increased inflammation and cell death. By contrast, WT-exosomes encased higher levels of miR-223, which could be delivered to cardiomyocytes, resulting in down-regulation of Sema3A and Stat3. These data for the first time indicate that exosomal miR-223 plays an essential role for MSC-induced cardio-protection in sepsis.

No MeSH data available.


Related in: MedlinePlus

MiR-223 is critical for MSC-mediated inhibitory effects on the cytokine production in macrophages upon LPS challenge.(A) A diagram of cell co-culture system in which macrophages (RAW264.7 cells) were cultured in the lower chamber and MSCs were cultured in the upper chamber of a 12-well insert. (B–D) Inhibition of LPS-triggered TNF-α (B), IL-1β (C), and IL-6 (D) production was more remarkable in macrophages co-cultured with WT-MSCs than those co-cultured with KO-MSCs. (n = 3 wells, *p < 0.05, vs. Medium controls and KO-MSC samples). Similar results were observed in two additional, independent experiments.
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f3: MiR-223 is critical for MSC-mediated inhibitory effects on the cytokine production in macrophages upon LPS challenge.(A) A diagram of cell co-culture system in which macrophages (RAW264.7 cells) were cultured in the lower chamber and MSCs were cultured in the upper chamber of a 12-well insert. (B–D) Inhibition of LPS-triggered TNF-α (B), IL-1β (C), and IL-6 (D) production was more remarkable in macrophages co-cultured with WT-MSCs than those co-cultured with KO-MSCs. (n = 3 wells, *p < 0.05, vs. Medium controls and KO-MSC samples). Similar results were observed in two additional, independent experiments.

Mentions: It is well appreciated that the large amounts of pro-inflammatory cytokines triggered by bacterial infection are mostly released from macrophages1. Importantly, macrophages, as autocrine and paracrine signaling mediators, could initiate further inflammatory responses in both neighboring macrophages and other types of cells1. To determine whether MSCs could directly suppress sepsis-induced inflammatory cytokine release from macrophages, we employed a well-controlled in vitro system of cell co-culture in which mouse MSCs were cultured in the upper chamber and RAW264.7 macrophages were seeded in the lower chamber (Fig. 3A), followed by treatment with bacterial endotoxin, LPS. We observed that LPS remarkably stimulated macrophages to release cytokines (TNF-α, IL-1β, and IL-6) (Fig. 3B–D). However, when macrophages were co-cultured with WT-MSCs, LPS-caused production of TNF-α, IL-1β, and IL-6 was dramatically inhibited (Fig. 3B–D). Notably, miR-223-KO MSCs did not significantly attenuate the secretion of these pro-inflammatory factors in macrophages upon LPS challenge (Fig. 3B–D). These results suggest: 1) immune-regulatory mechanisms of MSCs in sepsis may take effect through paracrine factors rather than direct cell contact; and 2) endogenous miR-223 may be critical, at least in part, for MSC-elicited immuno-suppression.


Exosomal miR-223 Contributes to Mesenchymal Stem Cell-Elicited Cardioprotection in Polymicrobial Sepsis.

Wang X, Gu H, Qin D, Yang L, Huang W, Essandoh K, Wang Y, Caldwell CC, Peng T, Zingarelli B, Fan GC - Sci Rep (2015)

MiR-223 is critical for MSC-mediated inhibitory effects on the cytokine production in macrophages upon LPS challenge.(A) A diagram of cell co-culture system in which macrophages (RAW264.7 cells) were cultured in the lower chamber and MSCs were cultured in the upper chamber of a 12-well insert. (B–D) Inhibition of LPS-triggered TNF-α (B), IL-1β (C), and IL-6 (D) production was more remarkable in macrophages co-cultured with WT-MSCs than those co-cultured with KO-MSCs. (n = 3 wells, *p < 0.05, vs. Medium controls and KO-MSC samples). Similar results were observed in two additional, independent experiments.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4562230&req=5

f3: MiR-223 is critical for MSC-mediated inhibitory effects on the cytokine production in macrophages upon LPS challenge.(A) A diagram of cell co-culture system in which macrophages (RAW264.7 cells) were cultured in the lower chamber and MSCs were cultured in the upper chamber of a 12-well insert. (B–D) Inhibition of LPS-triggered TNF-α (B), IL-1β (C), and IL-6 (D) production was more remarkable in macrophages co-cultured with WT-MSCs than those co-cultured with KO-MSCs. (n = 3 wells, *p < 0.05, vs. Medium controls and KO-MSC samples). Similar results were observed in two additional, independent experiments.
Mentions: It is well appreciated that the large amounts of pro-inflammatory cytokines triggered by bacterial infection are mostly released from macrophages1. Importantly, macrophages, as autocrine and paracrine signaling mediators, could initiate further inflammatory responses in both neighboring macrophages and other types of cells1. To determine whether MSCs could directly suppress sepsis-induced inflammatory cytokine release from macrophages, we employed a well-controlled in vitro system of cell co-culture in which mouse MSCs were cultured in the upper chamber and RAW264.7 macrophages were seeded in the lower chamber (Fig. 3A), followed by treatment with bacterial endotoxin, LPS. We observed that LPS remarkably stimulated macrophages to release cytokines (TNF-α, IL-1β, and IL-6) (Fig. 3B–D). However, when macrophages were co-cultured with WT-MSCs, LPS-caused production of TNF-α, IL-1β, and IL-6 was dramatically inhibited (Fig. 3B–D). Notably, miR-223-KO MSCs did not significantly attenuate the secretion of these pro-inflammatory factors in macrophages upon LPS challenge (Fig. 3B–D). These results suggest: 1) immune-regulatory mechanisms of MSCs in sepsis may take effect through paracrine factors rather than direct cell contact; and 2) endogenous miR-223 may be critical, at least in part, for MSC-elicited immuno-suppression.

Bottom Line: However, WT-MSCs were able to provide protection which was associated with exosome release.Conversely, WT-MSC-derived-exosomes displayed protective effects.By contrast, WT-exosomes encased higher levels of miR-223, which could be delivered to cardiomyocytes, resulting in down-regulation of Sema3A and Stat3.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacology and Cell Biophysics, University of Cincinnati College of Medicine, Cincinnati, OH, USA.

ABSTRACT
Mesenchymal stem cells (MSCs) have been shown to elicit cardio-protective effects in sepsis. However, the underlying mechanism remains obscure. While recent studies have indicated that miR-223 is highly enriched in MSC-derived exosomes, whether exosomal miR-223 contributes to MSC-mediated cardio-protection in sepsis is unknown. In this study, loss-of-function approach was utilized, and sepsis was induced by cecal ligation and puncture (CLP). We observed that injection of miR-223-KO MSCs at 1 h post-CLP did not confer protection against CLP-triggered cardiac dysfunction, apoptosis and inflammatory response. However, WT-MSCs were able to provide protection which was associated with exosome release. Next, treatment of CLP mice with exosomes released from miR-223-KO MSCs significantly exaggerated sepsis-induced injury. Conversely, WT-MSC-derived-exosomes displayed protective effects. Mechanistically, we identified that miR-223-KO exosomes contained higher levels of Sema3A and Stat3, two known targets of miR-223 (5p &3p), than WT-exosomes. Accordingly, these exosomal proteins were transferred to cardiomyocytes, leading to increased inflammation and cell death. By contrast, WT-exosomes encased higher levels of miR-223, which could be delivered to cardiomyocytes, resulting in down-regulation of Sema3A and Stat3. These data for the first time indicate that exosomal miR-223 plays an essential role for MSC-induced cardio-protection in sepsis.

No MeSH data available.


Related in: MedlinePlus