Orally bioactive compounds that induce γ globin gene expression at tolerable doses are needed for optimal treatment of the β-hemoglobinopathies. Short-chain fatty acids (SCFAs) of 2 to 6 carbons in length induce γ globin expression in animal models, and butyrate, phenylbutyrate, and valproate induce γ globin in human patients. The usefulness of these compounds, however, is limited by requirements for large doses because of their rapid metabolism and their tendency to inhibit cell proliferation, which limits the pool of erythroid progenitors in which γ globin can be induced. Selected short-chain fatty acid derivatives (SCFADs) were recently found to induce γ globin and to stimulate the proliferation of hematopoietic cells in vitro. These SCFADs are now evaluated in vivo in nonanemic transgenic mice containing the human β globin gene locus and in anemic phlebotomized baboons. In mice treated with a SCFAD once daily for 5 days, γ globin mRNA increased 2-fold, reticulocytes increased 3- to 7-fold, and hematocrit levels increased by 27%. Administration of 3 SCFADs in anemic baboons increased F-reticulocytes 2- to 15-fold over baseline and increased total hemoglobin levels by 1 to 2 g/dL per week despite ongoing significant daily phlebotomy. Pharmacokinetic studies demonstrated 90% oral bioavailability of 2 SCFADs, and targeted plasma levels were maintained for several hours after single oral doses equivalent to 10% to 20% of doses required for butyrate. These findings identify SCFADs that stimulate γ globin gene expression and erythropoiesis in vivo, activities that are synergistically beneficial for treatment of the β hemoglobinopathies and useful for the oral treatment of other anemias.

The histone deacetylase inhibitors (HDA-CIs) butyrate and trichostatin A activate γ-globin expression via a p38 mitogen-activating protein kinase (MAPK)-dependent mechanism. We hypothesized that down-stream effectors of p38 MAPK, namely activating transcription factor-2 (ATF-2) and cyclic AMP response element (CRE) binding protein (CREB), are intimately involved in fetal hemoglobin induction by these agents. In this study, we observed increased ATF-2 and CREB1 phosphorylation mediated by the HDACIs in K562 cells, in conjunction with histone H4 hyperacetylation. Moreover, enhanced DNA-protein interactions occurred in the CRE in the ^Gγ-globin promoter (G-CRE) in vitro after drug treatments; subsequent chromatin immunoprecipitation assay confirmed ATF-2 and CREB1 binding to the G-CRE in vivo. Enforced expression of ATF-2 and CREB produced ^Gγ-promoter trans-activation which was abolished by a 2-base pair mutation in the putative G-CRE. The data presented herein demonstrate that γ-gene induction by butyrate and trichostatin A involves ATF-2 and CREB1 activation via p38 MAPK signaling.

The vascular pathobiology of sickle cell anemia involves inflammation, coagulation, vascular stasis, reperfusion injury, iron-based oxidative biochemistry, defi

Background: Ethanol exposure to rodents during postnatal day 7 (P7), which is comparable to the third trimester of human pregnancy, induces long-term potentiation and memory deficits. However, the molecular mechanisms underlying these deficits are still poorly understood. Methods: In the present study, we explored the potential role of epigenetic changes at cannabinoid type 1 (CB1R) exon1 and additional CB1R functions, which could promote memory deficits in animal models of fetal alcohol spectrum disorder. Results: We found that ethanol treatment of P7 mice enhances acetylation of H4 on lysine 8 (H4K8ace) at CB1R exon1, CB1R binding as well as the CB1R agonist-stimulated GTPγS binding in the hippocampus and neocortex, two brain regions that are vulnerable to ethanol at P7 and are important for memory formation and storage, respectively. We also found that ethanol inhibits cyclic adenosine monophosphate response element-binding protein (CREB) phosphorylation and activity-regulated cytoskeleton-associated protein (Arc) expression in neonatal and adult mice. The blockade or genetic deletion of CB1Rs prior to ethanol treatment at P7 rescued CREB phosphorylation and Arc expression. CB1R knockout mice exhibited neither ethanol-induced neurodegeneration nor inhibition of CREB phosphorylation or Arc expression. However, both neonatal and adult mice did exhibit enhanced CREB phosphorylation and Arc protein expression. P7 ethanol-treated adult mice exhibited impaired spatial and social recognition memory, which were prevented by the pharmacological blockade or deletion of CB1Rs at P7. Conclusions: Together, these findings suggest that P7 ethanol treatment induces CB1R expression through epigenetic modification of the CB1R gene, and that the enhanced CB1R function induces pCREB, Arc, spatial, and social memory deficits in adult mice.