BACKGROUND: Mesenchymal stem cells (MSCs) can suppress and enhance immune functions. MSCs show promise as off-the-shelf cellular therapy for several disorders, including inflammation. OBJECTIVE: We investigated the effects of MSCs on the proliferation of PBMCs to allergic subjects (dust mite [DM]), allergic asthmatic subjects, or both. METHODS: Proliferation was studied by using tritiated thymidine uptake with or without MSCs. The refractoriness of PBMCs to DM was examined after preconditioning with MSCs and after repeated challenge with low-dose DM. Flow cytometry was used to study regulatory T cells and dendritic cells (DCs), and ELISA was used to study cytokine production. RESULTS: Seven subjects with allergic asthma met the inclusion/exclusion criteria. MSCs significantly (P <.05) reduced the proliferation of 6 subjects with allergic asthma but not those with allergy alone. The effect was specific to the allergen because MSCs did not affect challenges to tetanus toxoid. There was no change in CD4/CD25/forkhead box protein 3-positive cells, although there were decreased IFN-γ and increased IL-10 levels. Numbers of mature DCs were increased 6-fold. Refractoriness to DM was achieved by means of repeated exposure to low-dose DM and MSCs and also MSC- preconditioned MSC. CONCLUSION: MSCs suppressed the proliferation of DM-challenged PBMCs from allergic asthmatic subjects but not from allergic subjects without asthma. MSCs blunted the maturation of DCs but not regulatory T cells. Repeated exposure to low-dose DM and MSCs, as well as preconditioning of PBMCs with MSCs, caused refractoriness to DM. These findings have implications for the use of MSCs in attenuation of the inflammatory responses to allergic triggers in asthmatic patients with off-the-shelf MSCs.

OBJECTIVE: The emerging field of psychiatric epigenetics is constrained by the dearth of research methods feasible in living patients. With this focus, we report on two separate approaches, one in vitro and one in vivo, developed in our laboratory. METHOD: In the first approach, we isolated lymphocytes from 12 subjects and cultured their cells with either 0.7mM valproic acid (VPA), 100nM Trichostatin A (TSA), or DMSO (control) for 24h based upon previous dose response experiments. We then measured GAD67 mRNA expression using realtime RT-PCR, total acetylated histone 3 (H3K9,K14ac) levels using Western blot analysis, and attachment of H3K9,K14ac to the GAD67 promoter using ChIP. In the second approach, we measured GAD67 mRNA and total H3K9,K14ac levels in lymphocytes from 11 schizophrenia and 7 bipolar patients before and after 4 weeks of clinical treatment with Depakote ER((R))(VPA). RESULTS: In the first approach, VPA induced a 383% increase in GAD67 mRNA, an 89% increase in total H3K9,K14ac levels, and a 482% increase in H3K9,K14ac attachment to the GAD67 promoter. TSA induced comparable changes on all measures. In the second approach, bipolar subjects had significantly higher baseline levels of H3K9,K14ac compared to subjects with schizophrenia. Subjects with clinically relevant serum levels of VPA (65mug/mL) showed a significant increase in GAD67 mRNA expression. CONCLUSIONS: Our results utilizing two separate approaches for examining chromatin remodeling in real clinical time provide possible means to investigate epigenetic events in living patients.

Levels of acetylated Histone 3 and 4 proteins are strongly predictive of a chromatin structure that is conducive to gene expression. In cell and animal studies, valproic acid is a potent inhibitor of histone deactylating enzymes, and consequently results in increased levels of acetylated Histone 3 (acH3) and acetylated Histone 4 proteins (acH4). To examine this effect in a clinical setting, 14 schizophrenic and bipolar patients were treated with valproic acid (Depakote ER(R)), either as monotherapy or in combination with antipsychotics, over a period of 4 weeks. AcH3 and acH4 levels from lymphocyte nuclear protein extracts were measured by Western Blot. Treatment with Depakote ER resulted in a significant increase of acH3 and a trend-level increase of acH4. Levels of valproic acid were positively and significantly correlated with percent increase in acH3 but not acH4. Schizophrenia patients were significantly less likely to increase their acH3 and acH4 levels after 4 weeks on Depakote ER. The authors consider these results in the context of future application of HDAC inhibitors to the treatment of psychiatric disorders.