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Background Aberrant expression of circular RNAs (circRNAs) contributes to the initiation and progression of pulmonary hypertension (PH). Hypoxia‐inducible factor (HIF) is a well‐known modulator of hypoxia‐induced PH. The role and underlying mechanism of circRNAs in the regulation of HIF expression remains elusive. Methods and Results We profiled pulmonary artery transcriptomes using RNA sequencing and screened circRNAs associated with hypoxia treatment. The expression of a novel circRNA, circ_chr11_67292179–67294612 (circ‐myh8), was increased by hypoxia in a time‐dependent manner. We evaluated the effects of circ‐myh8 overexpression by adeno‐associated virus or inhibition by short hairpin RNA on proliferation and cell cycling in mice and pulmonary artery smooth muscle cells. Overexpression of circ‐myh8 promotes PH under normoxia, and disruption of circ‐myh8 by short hairpin RNA mitigates PH in chronic hypoxic mice. Biologically, circ‐myh8 induces the proliferation and cell‐cycle progression of pulmonary artery smooth muscle cells in vivo and in vitro. Mechanistically, RNA pull‐down and RNA immunoprecipitation assays were used to examine the interaction of circRNAs with the binding protein KAT7 (lysine acetyltransferase 7). The acetylation level of lysine 5 of histone H4 in the transcriptional initiation region of HIF1α was determined by chromatin immunoprecipitation assay followed by reverse transcription‐quantitative polymerase chain reaction. Circ‐myh8 acts as a modular scaffold to recruit histone acetyltransferase KAT7 to the promoters of HIF1α, which elicits acetylation of lysine 5 of histone H4 in their promoters. Conclusions Our findings not only reveal the pivotal roles of circ‐myh8 in governing histone modification in anti‐PH treatment but also advocate triggering the circ‐myh8/KAT7/HIF1α pathway to combat PH.

Objectives Pancreatic cancer (PC) is a highly malignant tumor with poor detection sensitivity and specificity in biomarkers and diagnosis. Previous research indicated that serum Ephrin type-A receptor 2 in exosomes (Exo-EphA2) was highly expressed and might have facilitated cell migration in PC cells. However, the dynamics of clinical performance of serum Exo-EphA2 in PC patients are unknown. Thus, this study evaluated serum Exo-EphA2 as a potential diagnostic biomarker in PC. Methods The expressions of serum Exo-EphA2 were assessed by enzyme-linked immunosorbent assay for N = 353 serum samples, including from 204 PC patients, 75 patients with benign pancreatic disease, and 74 healthy control patients. Carbohydrate antigen 19-9 (CA 19-9) and carbohydrate antigen 242 (CA 242) were measured by automated immunoassay. Results Serum Exo-EphA2 levels were significantly higher in PC patients than in benign pancreatic disease and healthy control patients. Receiver operating characteristic curve analysis suggested that using combined diagnoses of Exo-EphA2 with CA 19-9 and CA 242 was more effective to discriminate early stage (stage I and II) in PC than in healthy controls and benign disease patients. Conclusions Novel findings suggest that serum Exo-EphA2 is a potential early diagnostic biomarker complementing CA 19-9 and CA 242 in PC.

Supplemental Digital Content is available in the text, Recent studies have proposed that the ASAP1 gene participates in regulating the adaptive immune response to Mycobacterium tuberculosis infection. A GWAS study has reported that ASAP1 polymorphisms (rs4733781 and rs10956514) were associated with the risk of tuberculosis (TB) in Russians. But due to population heterogeneity, different races would have different causative polymorphisms, and the aim of this study was to investigate the association between single nucleotide polymorphisms (SNPs) of the ASAP1 gene and TB risk in Chinese population. A total of 7 SNPs in the ASAP1 gene were genotyped in 1115 Western Chinese Han and 914 Tibetan population using an improved multiplex ligation detection reaction (iMLDR) method. The associations of SNPs with TB risk and clinical phenotypes were determined based on the distributions of allelic frequencies and different genetic models. A meta-analysis was carried out to further assess the relationship between ASAP1 polymorphism and TB risk. Statistical comparisons of cases and controls after correction for multiple testing did not yield any significant associations with the risk of TB via analyses of a single locus, haplotype, and subgroup differences. Meta-analysis showed no evidence supporting association between rs10956514 and overall risk for TB. Subsequent analysis referring to the genotypes of SNPs in relationship to clinical phenotypes identified that rs4236749 was associated with different serum C-reactive protein levels, suggesting a role of this locus in influencing the inflammatory state of Western Chinese Han patients with TB. Our present data revealed that ASAP1 polymorphisms are unlikely to confer susceptibility to TB in the Western Chinese Han and Tibetan populations, which challenges the promising roles of the ASAP1 gene in the development of TB and highlights the importance of validating the association findings across ethnicities.

Objective: Laquinimod is an orally administered CNS-active immunomodulator currently in phase III clinical trials for therapy of relapsing remitting multiple sclerosis (RRMS). Data show that RRMS patients show beneficial effects of laquinimod 0.6mg on clinical disease activity as evidenced by slowing of the progression of disability, reducing the rate of MRI-measured brain volume loss, and reducing relapse rate. The current work examines the mechanisms underlying these effects. Background Laquinimod crosses the blood-brain barrier and enters the CNS, thus in addition to peripheral effects it may act directly on CNS-resident lineages including oligodendrocytes, microglia and astrocytes. Increasing evidence implicates reactive astrocytes as critical regulators of CNS inflammation and repair in MS. Design/Methods: Here, we report that laquinimod profoundly impacts proinflammatory gene expression in a human in vitro model of reactive astrogliosis. Results: Interleukin-1beta (IL-1β) is implicated in lesion pathogenesis in RRMS, and in primary human astrocyte cultures it strongly induced inflammatory factors including cytokines, chemokines and reactive nitrogen species. Importantly, at therapeutic concentrations, laquinimod abrogated IL-1β-induced induction of cytokines including tumor necrosis factor-α (TNFα) and IL-6, and inducible nitric oxide synthase. Laquinimod also differentially regulated IL-1β-induced expression of CXC and CC chemokines, suggesting that it acts as an immunomodulator rather than an immunosuppressant in astrocyte cultures. IL-1β exerts its effects via the transcription factor NF-κB, and suggesting mechanism, laquinimod pretreatment of human astrocytes downregulated NF-κB activation. Conclusions: Collectively, these data reveal laquinimod as a regulator of the proinflammatory phenotype in a human model of reactive astrogliosis, and suggest that it may act centrally on resident CNS cells to restrict pathology in MS lesions. Supported by: A research grant from Teva Pharmaceuticals. Disclosure: Dr. Pham has nothing to disclose. Dr. Zhang has nothing to disclose. Dr. Hayardeny Nisimov has nothing to disclose. Dr. John has received personal compensation for activities with EMD Serono, Teva Neuroscience, and Biogen Idec. Dr. John has received research support from Teva Neuroscience, and Vaccinex Inc.