Send to

Choose Destination
See comment in PubMed Commons below
Free Radic Biol Med. 2007 Nov 15;43(10):1394-408. Epub 2007 Jul 20.

N-acetylcysteine protects dental pulp stromal cells from HEMA-induced apoptosis by inducing differentiation of the cells.

Author information

The Jane and Jerry Weintraub Center for Reconstructive Biotechnology, Dental Research Institute, Division of Oral Biology and Medicine, UCLA School of Dentistry and Medicine, University of California at Los Angeles, Los Angeles, CA 90095, USA.


Resin-based materials are now widely used in dental restorations. Although the use of these materials is aesthetically appealing to patients, it carries the risk of local and systemic adverse effects. The potential risks are direct damage to the cells and induction of immune-based hypersensitivity reactions. Dental pulp stromal cells (DPSCs) and oral keratinocytes are the major cell types which may come in contact with dental resins such as 2-hydroxyethyl methacrylate (HEMA) after dental restorations. Here we show that N-acetylcysteine (NAC) inhibits HEMA-induced apoptotic cell death and restores the function of DPSCs and oral epithelial cells. NAC inhibits HEMA-mediated toxicity through induction of differentiation in DPSCs, because the genes for dentin sialoprotein, osteopontin (OPN), osteocalcin, and alkaline phosphatase, which are induced during differentiation, are also induced by NAC. Unlike NAC, vitamins E and C, which are known antioxidant compounds, failed to prevent either HEMA-mediated cell death or the decrease in VEGF secretion by human DPSCs. More importantly, when added either alone or in combination with HEMA, vitamin E and vitamin C did not increase the gene expression for OPN, and in addition vitamin E inhibited the protective effect of NAC on DPSCs. NAC inhibited the HEMA-mediated decrease in NF-kappaB activity, thus providing a survival mechanism for the cells. Overall, the studies reported in this paper indicate that undifferentiated DPSCs have exquisite sensitivity to HEMA-induced cell death, and their differentiation in response to NAC resulted in an increased NF-kappaB activity, which might have provided the basis for their increased protection from HEMA-mediated functional loss and cell death.

[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science Icon for PubMed Central
    Loading ...
    Support Center