Inhibition of pancreatic stellate cell activity by adipose-derived stem cells

BACKGROUND：Pancreatic stellate cells（PSCs）play a critical role in the development of pancreatic fibrosis.In this study we used a novel method to isolate and culture rat PSCs and then investigated the inhibitory effects of adipose-derived stem cells（ADSCs）on activation and proliferation of PSCs.METHODS：Pancreatic tissue was obtained from SpragueDawley rats for PSCs isolation.Transwell cell cultures were adopted for co-culture of ADSCs and PSCs. PSCs prolifera- tion and apoptosis were determined using CCK-8 and flow cytometry, respectively, a-SMA expressions were analyzed using Western blotting. The levels of cytokines [nerve growth factor （NGF）, interleukin-10 （IL-10） and transforming growth factor-ill （TGF-[31）] in conditioned medium were detected by ELISA. Gene expression （MMP-2, MMP-9 and TIMP-1） was analyzed using qRT-PCR. RESULTS： This method produced 17.6_＋6.5 ~ 103 ceils per gram of the body weight with a purity of 90%-95% and a viability of 92%-97%. Co-culture of PSCs with ADSCs significantly inhib- ited PSCs proliferation and induced PSCs apoptosis. Moreover, a-SMA expression was significantly reduced in PSCs＋ADSCs compared with that in PSC-only cultures, while expression of fibrinolytic proteins （e.g., MMP-2 and MMP-9） was upregulated and anti-fibrinolytic protein （TIMP-1） was downregulated. In addition, NGF expression was up-regulated, but IL-10 and TGF-β1 expressions were down-regulated in the coculture conditioned medium compared with those in the PSC- only culture medium. CONCLUSIONS： This study provided an easy and reliable technique to isolate PSCs. The data demonstrated the inhibitory effects of ADSCs on the activation and proliferation of PSCs in vitro.

Role of reactive oxygen species in the renal fibrosis

Renal fibrosis is a common pathway of progressive renal diseases leading to end-stage renal disease regardless of the etiology. Accumulating evidence indicates that oxidative stress, resulting in generation of reactive oxygen species （ROS）, plays a critical role in the initiation and progression of fibrotic diseases. Nicotinamide adenine dinucleotide phosphate （NADPH） oxidase is the predominant enzyme source for ROS generation and is now recognized as a key mediator of cell proliferation and matrix accumulation in renal disease. Multiple stimuli and agonists, such as transforming growth factor , tumor necrosis factor, platelet derived growth factor, angiotensin II, hyperglycemia, oxidized low-density lipoprotein and albumin have been shown to alter the activity or expression of the NADPH oxidase and ultimately increase ROS production. ROS directly incites damage to biologically important macromolecules and leads to generation of the so-called advanced oxidation protein products （AOPPs） and advanced glycation end products, which are not only markers of oxidative stress but also cause renal injury. Targeting NADPH oxidase and/or reducing AOPPs production miaht be a novel strateav for the theraoeutic intervention of varietv of fibrotic kidney disorders.