Search

Mesenchymal stem cells (MSCs) have attracted a great deal of interest as a therapeutic tool for renal fibrosis. Although both adipose-derived and bone marrow-derived MSCs (ADSCs and BMSCs, respectively) suppress renal fibrosis, which of these two has a stronger therapeutic effect remains unclear. This study aimed to compare the antifibrotic effects of ADSCs and BMSCs extracted from adipose tissue and bone marrow derived from the same rats. When cultured in serum-containing medium, ADSCs had a more potent inhibitory effect than BMSCs on renal fibrosis induced by ischemia-reperfusion injury in rats. ADSCs and BMSCs cultured in serum-free medium were equally effective in suppressing renal fibrosis. Mice infused with ADSCs (serum-containing or serum-free cultivation) had a higher death rate from pulmonary embolism than those infused with BMSCs. In vitro, mRNA levels of tissue factor, tumor necrosis factor-α-induced protein 6 and prostaglandin E synthase were higher in ADSCs than in BMSCs, while that of vascular endothelial growth factor was higher in BMSCs than in ADSCs. Although ADSCs had a stronger antifibrotic effect, these findings support the consideration of thromboembolism risk in clinical applications. Our results emphasize the importance of deciding between ADSCs and BMSCs based upon the target disease and culture method. [ABSTRACT FROM AUTHOR]

Mesenchymal stem cells (MSCs) administered for therapeutic purposes can be activated by interferon-γ (IFN-γ) secreted from natural killer cells in injured tissues and exert anti-inflammatory effects. These processes require a substantial period of time, leading to a delayed onset of MSCs' therapeutic effects. In this study, we investigated whether pretreatment with IFN-γ could potentiate the anti-fibrotic ability of MSCs in rats with ischemia–reperfusion injury (IRI) and unilateral ureter obstruction. Administration of MSCs treated with IFN-γ strongly reduced infiltration of inflammatory cells and ameliorated interstitial fibrosis compared with control MSCs without IFN-γ treatment. In addition, conditioned medium obtained from IFN-γ-treated MSCs decreased fibrotic changes in cultured cells induced by transforming growth factor-β1 more efficiently than that from control MSCs. Most notably, secretion of prostaglandin E2 from MSCs was significantly increased by treatment with IFN-γ. Increased prostaglandin E2 in conditioned medium obtained from IFN-γ-treated MSCs induced polarization of immunosuppressive CD163 and CD206-positive macrophages. In addition, knockdown of prostaglandin E synthase weakened the anti-fibrotic effects of MSCs treated with IFN-γ in IRI rats, suggesting the involvement of prostaglandin E2 in the beneficial effects of IFN-γ. Administration of MSCs treated with IFN-γ might represent a promising therapy to prevent the progression of renal fibrosis. [ABSTRACT FROM AUTHOR]

Background: Mesenchymal stem cells (MSCs) have been reported to promote the regeneration of injured tissue via their paracrine abilities, which are enhanced by hypoxic preconditioning. In this study, we examined the therapeutic efficacy of hypoxia-preconditioned MSCs on renal fibrosis and inflammation in rats with ischemia-reperfusion injury (IRI). Methods: MSCs derived from rats and humans were incubated in 1% O2 conditions (1%O2 MSCs) for 24 h. After IRI, 1%O2 MSCs or MSCs cultured under normoxic conditions (21%O2 MSCs) were injected through the abdominal aorta. At 7 or 21 days post-injection, the rats were sacrificed and their kidneys were analyzed. In in vitro experiments, we examined whether 1%O2 MSCs enhanced the ability to produce anti-fibrotic humoral factors using transforming growth factor (TGF)-β1-stimulated HK-2 cells incubated with conditioned medium from MSCs. Results: Administration of rat 1%O2 MSCs (1%O2 rMSCs) attenuated renal fibrosis and inflammation more significantly than rat 21%O2 MSCs. Notably, human 1%O2 MSCs (1%O2 hMSCs) also attenuated renal fibrosis to the same extent as 1%O2 rMSCs. Flow cytometry showed that 1%O2 hMSCs did not change human leukocyte antigen expression. Further in vitro experiments revealed that conditioned medium from 1%O2 MSCs further suppressed TGF-β1-induced fibrotic changes in HK-2 cells compared with 21%O2 MSCs. Hypoxic preconditioning enhanced vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) secretion. Interestingly, VEGF knockdown in 1%O2 MSCs attenuated HGF secretion and the inhibition of TGF-β1-induced fibrotic changes in HK-2 cells. In addition, VEGF knockdown in 1%O2 hMSCs reduced the anti-fibrotic effect in IRI rats. Conclusions: Our results indicate that hypoxia-preconditioned MSCs are useful as an allogeneic transplantation cell therapy to prevent renal fibrosis and inflammation. [ABSTRACT FROM AUTHOR]

Mesenchymal stem cells (MSCs) are a potential therapeutic tool for preventing the progression of acute kidney injury (AKI) to chronic kidney disease (CKD). Herein, we investigated the localization and maintenance of engrafted human bone marrow-derived MSCs in rats subjected to a renal ischemia-reperfusion injury (IRI) and compared the effectiveness of two intravascular injection routes via the renal artery or inferior vena cava. Renal artery injection of MSCs was more effective than intravenous injection at reducing IRI-induced renal fibrosis. Additionally, MSCs injected through the renal artery persisted in injured kidneys for over 21 days, whereas MSCs injected through the inferior vena cava survived for less than 7 days. This difference may be attributed to the antifibrotic effects of MSCs. Interestingly, MSCs injected through the renal artery were localized primarily in glomeruli until day 3 post-IRI, and they decreased in number thereafter. In contrast, the number of MSCs localized in tubular walls, and the interstitium increased gradually until day 21 post-IRI. This localization change may be related to areas of damage caused by IRI because ischemia-induced AKI leads to tubular cell damage. Taken together, these findings suggest renal artery injection of MSCs may be useful for preventing the progression of AKI to CKD. [ABSTRACT FROM AUTHOR]