Setd1a and NURF mediate chromatin dynamics and gene regulation during erythroid lineage commitment and differentiation.

The modulation of chromatin structure is a key step in transcription regulation in mammalian cells and eventually determines lineage commitment and differentiation. USF1/2, Setd1a and NURF complexes interact to regulate chromatin architecture in erythropoiesis, but the mechanistic basis for this regulation is hitherto unknown. Here we showed that Setd1a and NURF complexes bind to promoters to control chromatin structural alterations and gene activation in a cell context dependent manner. In human primary erythroid cells USF1/2, H3K4me3 and the NURF complex were significantly co-enriched at transcription start sites of erythroid genes, and their binding was associated with promoter/enhancer accessibility that resulted from nucleosome repositioning. Mice deficient for Setd1a, an H3K4 trimethylase, in the erythroid compartment exhibited reduced Ter119/CD71 positive erythroblasts, peripheral blood RBCs and hemoglobin levels. Loss of Setd1a led to a reduction of promoter-associated H3K4 methylation, inhibition of gene transcription and blockade of erythroid differentiation. This was associated with alterations in NURF complex occupancy at erythroid gene promoters and reduced chromatin accessibility. Setd1a deficiency caused decreased associations between enhancer and promoter looped interactions as well as reduced expression of erythroid genes such as the adult ß-globin gene. These data indicate that Setd1a and NURF complexes are specifically targeted to and coordinately regulate erythroid promoter chromatin dynamics during erythroid lineage differentiation.

Selective Inhibition of Autotaxin Is Efficacious in Mouse Models of Liver Fibrosis.

Autotaxin (ATX) is a secreted glycoprotein that converts lysophosphatidylcholine (LPC) to the bioactive phospholipid lysophosphatidic acid (LPA) and is the major enzyme generating circulating LPA. Inhibition of LPA signaling has profound antifibrotic effects in multiple organ systems, including lung, kidney, skin, and peritoneum. However, other LPA-generating pathways exist, and the role of ATX in localized tissue LPA production and fibrosis remains unclear and controversial. In this study, we describe the preclinical pharmacologic, pharmacokinetic, and pharmacodynamic properties of a novel small-molecule ATX inhibitor, PAT-505 [3-((6-chloro-2-cyclopropyl-1-(1-ethyl-1H-pyrazol-4-yl)-7-fluoro-1H-indol-3-yl) thio)-2-fluorobenzoic acid sodium salt]. PAT-505 is a potent, selective, noncompetitive inhibitor that displays significant inhibition of ATX activity in plasma and liver tissue after oral administration. When dosed therapeutically in a Stelic Mouse Animal Model of nonalcoholic steatohepatitis (NASH), PAT-505 treatment resulted in a small but significant improvement in fibrosis with only minor improvements in hepatocellular ballooning and hepatic inflammation. In a choline-deficient, high-fat diet model of NASH, therapeutic treatment with PAT-505 robustly reduced liver fibrosis with no significant effect on steatosis, hepatocellular ballooning, or inflammation. These data demonstrate that inhibiting autotaxin is antifibrotic and may represent a novel therapeutic approach for the treatment of multiple fibrotic liver diseases, including NASH.

Gestational Cytokines and the Developmental Expression of Obesity in Childhood.

OBJECTIVE: This study examined the extent to which maternal immune activity during pregnancy is associated with childhood adiposity, and if so, whether associations at birth differ from those in infancy and childhood. Sex-specific associations were also examined. METHODS: Participants were 1,366 singleton pregnancies from the Collaborative Perinatal Project (1959-1966). Interleukin-1ß (IL-1ß), IL-6, TNF-α, IL-8, and IL-10 in maternal sera were assayed repeatedly during pregnancy. Children's BMI was calculated repeatedly from birth through age 8 and derived age- and sex-normalized BMI z scores (BMIz). Linear mixed models were used to estimate the cumulative concentration of each cytokine in the second and third trimesters and then related this concentration to child BMIz. RESULTS: Children exposed to higher IL-1ß, IL-6, IL-8, and IL-10 concentrations had lower BMIz at birth but higher BMIz during childhood. Higher concentrations of IL-8 and IL-1ß were also associated with higher BMIz during infancy (B per log increase in IL-8 = 0.04; 95% CI: 0.02 to 0.07; B per log increase in IL-1ß = 0.03; 95% CI: 0.001 to 0.06). The associations between TNF-α and BMIz were in opposing directions in boys (B = -0.13; 95% CI: -0.31 to 0.04) and girls (B = 0.14; 95% CI: 0.02 to 0.26) during childhood. CONCLUSIONS: Maternal prenatal inflammation contributes to the age- and sex-specific programming of obesity risk in childhood.

Vaccination and risk of lone atrial fibrillation in the active component United States military.

PURPOSE: To evaluate the hypothesis that receipt of anthrax vaccine adsorbed (AVA) increases the risk of atrial fibrillation in the absence of identifiable underlying risk factors or structural heart disease (lone atrial fibrillation). METHODS: We conducted a retrospective population-based cohort study among U.S. military personnel who were on active duty during the period from January 1, 1998 through December 31, 2006. International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes were used to identify individuals diagnosed with atrial fibrillation in the Defense Medical Surveillance System, and electronic records were screened to include only individuals without evidence of predisposing medical conditions. We used multivariable Poisson regression to estimate the risk of lone atrial fibrillation after exposure to AVA. We also evaluated possible associations with influenza and smallpox vaccines. RESULTS: Our study population consisted of 2,957,091individuals followed for 11,329,746 person-years of service. Of these, 2,435 met our case definition for lone atrial fibrillation, contributing approximately 8,383 person-years of service. 1,062,176 (36%) individuals received at least one dose of AVA; the median person time observed post-exposure was 3.6 years. We found no elevated risk of diagnosed lone atrial fibrillation associated with AVA (adjusted risk ratio = 0.99; 95% confidence interval = 0.90, 1.09; p = 0.84). No elevated risk was observed for lone atrial fibrillation associated with influenza or smallpox vaccines given during military service. CONCLUSIONS: We did not find an increased risk of lone atrial fibrillation after AVA, influenza or smallpox vaccine. These findings may be helpful in planning future vaccine safety research.

Targeting T Cell Malignancies Using CD4CAR T-Cells and Implementing a Natural Safety Switch.

T cell malignancies are aggressive diseases with no standard treatment available, often resulting in poor patient outcomes. Lately, the recent FDA approval of a CD19 CAR T cell therapy for B cell acute lymphoblastic leukemia has earned nationwide attention, leading to the possibility that success of CD19 CAR therapy can be extended to T cell malignancies. However, the impact of T cell depletion due to a shared antigen pool remains an issue to be resolved. Here, we describe a CD4CAR capable of eliminating CD4-positive T cell acute lymphoblastic leukemia in a systemic mouse model, with CAMPATH (alemtuzumab) as a natural safety switch to deplete the infused CD4CAR T cells to prevent toxicities associated with CD4 cell aplasia. Our data support the potential use of CD4CAR T cells for the treatment of CD4-postive T-cell acute lymphoblastic leukemia malignancies or refractory disease in clinical settings.

Anti-CD19 chimeric antigen receptor targeting of CD19 + acute myeloid leukemia.

Aberrant expression of CD19 in acute myeloid leukemia (AML) is commonly associated with t(8;21)(q22;q22), although AML cases lacking this translocation occasionally express CD19. Mixed-phenotype acute leukemia also frequently expresses CD19. Chimeric antigen receptor (CAR) technology is a major breakthrough for cancer treatment, with the recent approval of CD19-directed CAR (CD19CAR) for treating B-cell malignancies. However, little information exists on using CD19CAR for other CD19 positive neoplasms such as AML. Our findings indicate that CD19CAR therapy can potentially be used for those with mixed phenotype leukemia and a subset of AML cases.

Identification of 4-(Aminomethyl)-6-(trifluoromethyl)-2-(phenoxy)pyridine Derivatives as Potent, Selective, and Orally Efficacious Inhibitors of the Copper-Dependent Amine Oxidase, Lysyl Oxidase-Like 2 (LOXL2).

LOXL2 catalyzes the oxidative deamination of ε-amines of lysine and hydroxylysine residues within collagen and elastin, generating reactive aldehydes (allysine). Condensation with other allysines or lysines drives the formation of inter- and intramolecular cross-linkages, a process critical for the remodeling of the ECM. Dysregulation of this process can lead to fibrosis, and LOXL2 is known to be upregulated in fibrotic tissue. Small-molecules that directly inhibit LOXL2 catalytic activity represent a useful option for the treatment of fibrosis. Herein, we describe optimization of an initial hit 2, resulting in identification of racemic-trans-(3-((4-(aminomethyl)-6-(trifluoromethyl)pyridin-2-yl)oxy)phenyl)(3-fluoro-4-hydroxypyrrolidin-1-yl)methanone 28, a potent irreversible inhibitor of LOXL2 that is highly selective over LOX and other amine oxidases. Oral administration of 28 significantly reduced fibrosis in a 14-day mouse lung bleomycin model. The (R,R)-enantiomer 43 (PAT-1251) was selected as the clinical compound which has progressed into healthy volunteer Phase 1 trials, making it the "first-in-class" small-molecule LOXL2 inhibitor to enter clinical development.

Expansion of hematopoietic stem cells for transplantation: current perspectives.

Hematopoietic stem cells (HSCs) are rare cells that have the unique ability to self-renew and differentiate into cells of all hematopoietic lineages. The expansion of HSCs has remained an important goal to develop advanced cell therapies for bone marrow transplantation and many blood disorders. Over the last several decades, there have been numerous attempts to expand HSCs in vitro using purified growth factors that are known to regulate HSCs. However, these attempts have been met with limited success for clinical applications. New developments in the HSC expansion field coupled with gene therapy and stem cell transplant should encourage progression in attractive treatment options for many disorders including hematologic conditions, immunodeficiencies, and genetic disorders.