Protein arginine N-methyltransferase 4 (PRMT4) contributes to lymphopenia in experimental sepsis.

BACKGROUND: One hallmark of sepsis is the reduced number of lymphocytes, termed lymphopenia, that occurs from decreased lymphocyte proliferation or increased cell death contributing to immune suppression. Histone modification enzymes regulate immunity by their epigenetic and non-epigenetic functions; however, the role of these enzymes in lymphopenia remains elusive. METHODS: We used molecular biological approaches to investigate the high expression and function of a chromatin modulator protein arginine N-methyltransferase 4 (PRMT4)/coactivator-associated arginine methyltransferase 1 in human samples from septic patients and cellular and animal septic models. RESULTS: We identified that PRMT4 is elevated systemically in septic patients and experimental sepsis. Gram-negative bacteria and their derived endotoxin lipopolysaccharide (LPS) increased PRMT4 in B and T lymphocytes and THP-1 monocytes. Single-cell RNA sequencing results indicate an increase of PRMT4 gene expression in activated T lymphocytes. Augmented PRMT4 is crucial for inducing lymphocyte apoptosis but not monocyte THP-1 cells. Ectopic expression of PRMT4 protein caused substantial lymphocyte death via caspase 3-mediated cell death signalling, and knockout of PRMT4 abolished LPS-mediated lymphocyte death. PRMT4 inhibition with a small molecule compound attenuated lymphocyte death in complementary models of sepsis. CONCLUSIONS: These findings demonstrate a previously uncharacterised role of a key chromatin modulator in lymphocyte survival that may shed light on devising therapeutic modalities to lessen the severity of septic immunosuppression.

Clinical Outcomes and Mortality Impact of Hyperbaric Oxygen Therapy in Patients With Carbon Monoxide Poisoning.

OBJECTIVES: Carbon monoxide poisoning affects 50,000 per year in the United States alone. Mortality is approximately 3%, and up to 40% of survivors suffer from permanent neurocognitive and affective deficits. Hyperbaric oxygen therapy has shown benefit on reducing the long-term neurologic sequelae of carbon monoxide poisoning but has not demonstrated improved survival. The objective of this study is to assess the efficacy of hyperbaric oxygen for acute and long-term mortality in carbon monoxide poisoning using a large clinical databank. DESIGN: Retrospective analysis. SETTING: University of Pittsburgh Medical Center healthcare system (Pittsburgh, PA). PATIENTS: One-thousand ninety-nine unique encounters of adult patients with carbon monoxide poisoning. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Baseline demographics, laboratory values, hospital charge transactions, discharge disposition, and clinical information from charting were obtained from the electronic medical record. In propensity-adjusted analysis, hyperbaric oxygen therapy was associated with a reduction in inpatient mortality (absolute risk reduction, 2.1% [3.7-0.9%]; p = 0.001) and a reduction in 1-year mortality (absolute risk reduction, 2.1% [3.8-0.4%]; p = 0.013). CONCLUSIONS: These data demonstrate that hyperbaric oxygen is associated with reduced acute and reduced 1-year mortality. Further studies are needed on the mortality effects of hyperbaric oxygen therapy in carbon monoxide poisoning.

Novel Inducers of Fetal Globin Identified through High Throughput Screening (HTS) Are Active In Vivo in Anemic Baboons and Transgenic Mice.

High-level fetal (γ) globin expression ameliorates clinical severity of the beta (ß) hemoglobinopathies, and safe, orally-bioavailable γ-globin inducing agents would benefit many patients. We adapted a LCR-γ-globin promoter-GFP reporter assay to a high-throughput robotic system to evaluate five diverse chemical libraries for this activity. Multiple structurally- and functionally-diverse compounds were identified which activate the γ-globin gene promoter at nanomolar concentrations, including some therapeutics approved for other conditions. Three candidates with established safety profiles were further evaluated in erythroid progenitors, anemic baboons and transgenic mice, with significant induction of γ-globin expression observed in vivo. A lead candidate, Benserazide, emerged which demonstrated > 20-fold induction of γ-globin mRNA expression in anemic baboons and increased F-cell proportions by 3.5-fold in transgenic mice. Benserazide has been used chronically to inhibit amino acid decarboxylase to enhance plasma levels of L-dopa. These studies confirm the utility of high-throughput screening and identify previously unrecognized fetal globin inducing candidates which can be developed expediently for treatment of hemoglobinopathies.

Is opium a real risk factor for esophageal cancer or just a methodological artifact? Hospital and neighborhood controls in case-control studies.

BACKGROUND: Control selection is a major challenge in epidemiologic case-control studies. The aim of our study was to evaluate using hospital versus neighborhood control groups in studying risk factors of esophageal squamous cell carcinoma (ESCC). METHODOLOGY/PRINCIPAL FINDINGS: We compared the results of two different case-control studies of ESCC conducted in the same region by a single research group. Case definition and enrollment were the same in the two studies, but control selection differed. In the first study, we selected two age- and sex-matched controls from inpatient subjects in hospitals, while for the second we selected two age- and sex-matched controls from each subject's neighborhood of residence. We used the test of heterogeneity to compare the results of the two studies. We found no significant differences in exposure data for tobacco-related variables such as cigarette smoking, chewing Nass (a tobacco product) and hookah (water pipe) usage, but the frequency of opium usage was significantly different between hospital and neighborhood controls. Consequently, the inference drawn for the association between ESCC and tobacco use did not differ between the studies, but it did for opium use. In the study using neighborhood controls, opium use was associated with a significantly increased risk of ESCC (adjusted OR 1.77, 95% CI 1.17-2.68), while in the study using hospital controls, this was not the case (OR 1.09, 95% CI 0.63-1.87). Comparing the prevalence of opium consumption in the two control groups and a cohort enrolled from the same geographic area suggested that the neighborhood controls were more representative of the study base population for this exposure. CONCLUSIONS/SIGNIFICANCE: Hospital and neighborhood controls did not lead us to the same conclusion for a major hypothesized risk factor for ESCC in this population. Our results show that control group selection is critical in drawing appropriate conclusions in observational studies.

Distinct clinical and immunologic profiles in severe malarial anemia and cerebral malaria in Zambia.

BACKGROUND: The mechanisms of severe malarial anemia and cerebral malaria, which are extreme manifestations of Plasmodium falciparum malaria, are not fully understood. METHODS: Children aged <6 years from southern Zambia presenting to the hospital with severe malarial anemia (n = 72), cerebral malaria (n = 28), or uncomplicated malaria (n = 66) were studied prospectively. Children with overlapping severe anemia and cerebral malaria were excluded. RESULTS: Low interleukin 10 concentrations had the strongest association with severe anemia (standard ß = .61; P < .001) followed by high tumor necrosis factor α and sFas concentrations, low weight-for-age z scores, presence of stool parasites, and splenomegaly (standard ß = .15-.25; P ≤ .031); most of these factors were also associated with lower reticulocytes. Greater parasitemia was associated with higher interleukin 10 and tumor necrosis factor α concentrations, whereas sulfadoxizole/pyrimethamine therapy and lower weight-for-age z scores were associated with lower interleukin 10 levels. Thrombocytopenia and elevated tissue plasminogen activator inhibitor 1 levels had the strongest associations with cerebral malaria (standard ß = .37 or .36; P < .0001), followed by exposure to traditional herbal medicine and hemoglobinuria (standard ß = .21-.31; P ≤ .006). CONCLUSIONS: Predictors of severe malarial anemia (altered immune responses, poor nutrition, intestinal parasites, and impaired erythropoiesis) differed from those of cerebral malaria (thrombocytopenia, herbal medicine, and intravascular hemolysis). Improved preventive and therapeutic measures may need to consider these differences.

Serum ferritin concentrations in Africans with low dietary iron.

In the setting of high dietary, several studies have provided evidence for a strong effect of both high dietary iron and an unidentified genetic locus on iron stores in Africans. To investigate whether these effects are discernible in the setting of low dietary iron, serum ferritin concentrations were measured in 194 Zimbabwean men >30 years of age and 299 postmenopausal women who consumed a non-iron-fortified diet and who did not drink iron-rich traditional beer or other alcoholic beverages. Comparisons were made with non-alcohol drinking African-Americans studied in the third National Health and Nutritional Examination Survey (NHANES III) who consume an iron-fortified diet. As stratified by age and sex, serum ferritin concentrations were significantly lower in the 493 Zimbabweans studied than in 1,380 comparable African-Americans (P < 0.0005). Nevertheless, nine Zimbabwean subjects (1.8% of all cases) had modestly elevated serum ferritin concentrations not associated with evidence of inflammation or hepatic dysfunction. These data suggest that mild serum ferritin concentration elevations may occur among Zimbabweans not exposed to high dietary iron and that iron fortification of the diet may have substantial effects on serum ferritin concentration.