International journal of molecular medicine
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Mesenchymal stem cells (MSCs) have been successfully used for the treatment of experimental intracerebral hemorrhage (ICH). However, the neuroprotective mechanisms through which MSCs improve neurological functional recovery are not fully understood. In the present study, we tested the hypothesis that treatment with MSCs inhibits inflammation after ICH and reduces subsequent brain injury. ⋯ Consistently, we found a significant anti-inflammatory effect of Flk-1(+) hBMSCs on the ICH brain, including a decrease in neutrophil infiltration and microglial activation in the peri-ICH area, and downregulation of inflammatory mediators, such as interleukin (IL)-1β, IL-2, IL-4, IL-6, and tumor necrosis factor (TNF)-α. In addition, Flk-1+ hBMSC treatment significantly increased vascular density in the peri-ICH area, and transplanted Flk-1(+) hBMSCs were found to be incorporated into the cerebral vasculature 55 days after transplantation. Overall, these data suggest an essential role for Flk-1(+) hBMSCs in reducing inflammatory infiltration, promoting angiogenesis, and improving functional recovery after ICH in rats.
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Metallothioneins (MTs) are a family of cysteine-rich low molecular-weight proteins that can act as reactive oxygen species scavengers. Although it is known that the induction of MT expression suppresses various inflammatory disorders, the role of MTs in intestinal inflammation remains unclear. In this study, we investigated the effects of dextran sulfate sodium (DSS) administration in mice with targeted deletions of the MT-I/II genes. ⋯ MT-positive cells were detected in the lamina propria and submucosal layer by immunohistochemical and immunofluorescence staining, and were mainly co-localized in F4/80-positive macrophages. The production of inflammatory cytokines (TNF-α, IFN-γ and IL-17) from isolated peritoneal macrophages increased following lipopolysaccharide stimulation, and these increases were significantly enhanced in the macrophages obtained from the MT-I/II knockout mice. These data indicate that MTs play an important role in the prevention of colonic mucosal inflammation in a mouse model of DSS-induced colitis, thus suggesting that endogenous MTs play a protective role against intestinal inflammation.