Nerve growth factor-mediated paracrine regulation of hepatic stellate cells by multipotent mesenchymal stromal cells

Aims: Multipotent mesenchymal stromal cells (MSC) have been reported to prevent the development of liver fibrosis and have emerged as a promising strategy for cell-based therapy. However, the underlying therapeutic mechanism remains unclear. Hepatic stellate cells (SC) activation is a pivotal event in the development of liver fibrosis. Main methods: We hypothesized that MSC play an important role in regulating SC proliferation and apoptosis through paracrine mechanisms. To investigate the paracrine interactions between MSC and SC, a co-culture experimental model was developed using human MSC (hMSC) and human SC (hSC). Key findings: We demonstrate that hMSC and hSC both express nerve growth factor (NGF) receptor p75. Results acquired from transwell co-culture experiments using hSC and hMSC showed that hMSC secrete NGF, which enhances hSC apoptosis. Transcription factor nuclear factor kappa B (NF-KB) and B cell leukemia-xl (Bcl-xl) take part in the process. \Significance: These findings demonstrated that hMSC indirectly modulate activated hSC in vitro via NGF-mediated signaling cascades and provide a potential mechanism of how transplanted MSC are effective in treating liver fibrosis. (C) 2009 Elsevier Inc. All rights reserved.