S-Propargyl-Cysteine, a Novel Hydrogen Sulfide Donor, Inhibits Inflammatory Hepcidin and Relieves Anemia of Inflammation by Inhibiting IL-6/STAT3 Pathway

<div><p>Anemia of inflammation (AI) is clinically prevalent and greatly threatens public health. Traditional remedies have raised controversy during clinical practice, calling for alternative therapies. We have recently found that hydrogen sulfide (H₂S) inhibits inflammatory hepcidin, the critical mediator of AI. However, due to the chemical property of H₂S, there remains an urgent need for a stable H₂S donor in AI treatment. Here we reported that S-propargyl-cysteine (SPRC), a novel water-soluble H₂S donor, suppressed hepatic hepcidin and corrected hypoferremia induced by lipopolysaccharide. The effects of SPRC were reversed by inhibition of cystathionine γ-lyase, one of the major endogenous H₂S synthases. Moreover, SPRC reduced serum hepcidin, improved transferrin saturation, and maintained erythrocyte membrane integrity in a chronic mouse AI model. Consistently, splenomegaly was ameliorated and splenic iron accumulation relieved. Mechanism study indicated that serum IL-6 content and hepatic <i>Il-6</i> mRNA were decreased by SPRC, in parallel with reduced hepatic JAK2/STAT3 activation. On the whole, our data reveal the inhibition of inflammatory hepcidin by SPRC, and suggest SPRC as a potential remedy against AI.</p></div

SPRC reduces splenomegaly and corrects splenic iron accumulation in chronic AI model.

<p>(A) Representative images indicated relieved splenomegaly by SPRC. (B) Consistent results were observed with mouse spleen weight (n = 7). (C-D) Splenic iron accumulation was relieved by SPRC, as assessed by non-heme iron analysis and Perl’s Prussian blue staining (n = 7). Representative images are presented. Data are presented as the mean ± SEM. ^## <i>p</i> < 0.01, ^### <i>p</i> < 0.001 compared with the control group; * <i>p</i> < 0.05 compared with the model group.</p

SPRC reduces inflammatory hepcidin activation by inhibiting IL-6/JAK2/STAT3 pathway.

<p>(A) SPRC and NaHS markedly decreased serum IL-6 levels induced by LPS (n = 5). (B-D) Hepatic <i>Il-6</i>, <i>Tnfa</i> mRNA levels and JAK2/STAT3 phosphorylation were induced by LPS, and suppressed by SPRC and NaHS. Moreover, PAG diminished the effects of SPRC (n = 5). (E-F) Densitometry analysis of Fig 2D. (G-H) Hepatic mRNA levels of <i>Socs3</i> and <i>Saa2</i>, two target genes of STAT3 (n = 5). Representative immunoblots are presented. Whole uncropped images of Fig 2D are shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0163289#pone.0163289.s001" target="_blank">S1 Fig</a>. Data are presented as the mean ± SEM. ^### <i>p</i> < 0.001 compared with the control group; * <i>p</i> < 0.05, ** <i>p</i> < 0.01, *** <i>p</i> < 0.001, compared with the LPS group; ^@ <i>p</i> < 0.05, ^@@ <i>p</i> < 0.01, ^@@@ <i>p</i> < 0.001.</p

Hematological and mouse indices.

<p>Hematological and mouse indices.</p

SPRC improved AI by reducing hepatic IL-6/JAK2/STAT3 activation.

<p>(A) Serum IL-6 content was not significantly changed by SPRC (n = 7). (B) Hepatic Il-6 mRNA levels were suppressed by SPRC, though only 2-fold change was observed in the model group (n = 7). (C) SPRC successfully ameliorated hepatic JAK2/STAT3 phosphorylation in the turpentine model. (D-E) Densitometry analysis of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0163289#pone.0163289.g005" target="_blank">Fig 5C</a>. Representative immunoblots are presented. Whole uncropped images of Fig 4C are shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0163289#pone.0163289.s002" target="_blank">S2 Fig</a>. Data are presented as the mean ± SEM. ^# <i>p</i> < 0.05, ^### <i>p</i> < 0.001 compared with the control group; * <i>p</i> < 0.05, ** <i>p</i> < 0.01, *** <i>p</i> < 0.001 compared with the model group.</p

SPRC improves turpentine-induced AI <i>in vivo</i>.

<p>(A) A diagram about the induction of AI by turpentine and the application of SPRC. (B-C) SPRC treatment ameliorated serum hepcidin levels in turpentine-induced AI model, and a similar trend was observed in hepatic hepcidin mRNA expression (n = 7). (D-F) Total iron binding capacity (TIBC) was unchanged, while serum iron levels and transferrin (Tf) saturation were increased by SPRC (n = 7). (G) Representative images of blood smears with Wright-Giemsa staining showed that red blood cell morphology was improved by SPRC. Solid arrows indicate damaged erythrocytes. Data are presented as the mean ± SEM. ^## <i>p</i> < 0.01, ^### <i>p</i> < 0.001 compared with the control group; * <i>p</i> < 0.05, ** <i>p</i> < 0.01, *** <i>p</i> < 0.001, compared with the model group.</p

SPRC inhibits inflammatory hepcidin and hypoferremia induced by LPS.

<p>(A) Chemical structure of SPRC. (B-C) SPRC and NaHS showed no effects on hepatic and serum hepcidin in the absence of LPS (n = 5). (D) SPRC and NaHS increased serum H₂S content, as opposed to PAG (n = 5). (E-F) Hepatic hepcidin mRNA and serum hepcidin levels were suppressed by SPRC and NaHS, while PAG abolished the effects of SPRC (n = 5). (G) Consistent results were obtained with serum iron levels (n = 5). Data are presented as the mean ± SEM. ^### <i>p</i> < 0.001 compared with the control group; * <i>p</i> < 0.01, ** <i>p</i> < 0.01 compared with the LPS group; ^@ <i>p</i> < 0.05, ^@@ <i>p</i> < 0.01, ^@@@ <i>p</i> < 0.001.</p

Additional file 2: Figure S1. of The Tiotropium Safety and Performance in RespimatÂŽ (TIOSPIRÂŽ) Trial: Spirometry Outcomes

Forest plot of annual rate of FVC (A) and FEV1/FVC (B) decline in lung function by baseline characteristics. (DOCX108 kb

Quantitative Detection of MicroRNA in One Step <i>via</i> Next Generation Magnetic Relaxation Switch Sensing

One-step, quantitative and rapid detection of microRNA (miRNA) in tumor cells or tissues can provide critical information for clinical diagnosis and cancer treatment. In this work, we develop a magnetic relaxation switch sensing (MRS)-based miRNA sensor using magnetic microparticle (1 μm in diameter, MM₁₀₀₀)-DNA probe-magnetic nanoparticle (30 nm in diameter, MN₃₀) conjugates (MM₁₀₀₀-DNA-MN₃₀). In the presence of target miRNA, DSN enzyme selectively cleaves the DNA tether after miRNA/DNA hybridization to release MN₃₀ and leaves the miRNA intact to lead to the declustering of more MN₃₀ than before. In contrast to conventional MRS by measuring the change of transverse relaxation time (Δ<i>T</i>₂) induced by the aggregation or dissociation of magnetic particles in the presence of target, we use the cleaved MN₃₀ from conjugates as the direct readout of Δ<i>T</i>₂, which is more sensitive and stable. This MRS-based assay allows for one-step detection of 5 fM of miR-21 in urine samples, quantification of miR-21 from 100 cancer cells, and differentiation of the expression of miR-21 in tumor and surrounding tissues. The merits of this assay, rapidity, ability for quantitation, high sensitivity, and one-step operation, ensure a promising future in diagnostic technology

Genome-wide joint meta-analysis of SNP and SNP-by-smoking interaction identifies novel loci for pulmonary function.

Genome-wide association studies have identified numerous genetic loci for spirometic measures of pulmonary function, forced expiratory volume in one second (FEV(1)), and its ratio to forced vital capacity (FEV(1)/FVC). Given that cigarette smoking adversely affects pulmonary function, we conducted genome-wide joint meta-analyses (JMA) of single nucleotide polymorphism (SNP) and SNP-by-smoking (ever-smoking or pack-years) associations on FEV(1) and FEV(1)/FVC across 19 studies (total N = 50,047). We identified three novel loci not previously associated with pulmonary function. SNPs in or near DNER (smallest P(JMA = )5.00×10(-11)), HLA-DQB1 and HLA-DQA2 (smallest P(JMA = )4.35×10(-9)), and KCNJ2 and SOX9 (smallest P(JMA = )1.28×10(-8)) were associated with FEV(1)/FVC or FEV(1) in meta-analysis models including SNP main effects, smoking main effects, and SNP-by-smoking (ever-smoking or pack-years) interaction. The HLA region has been widely implicated for autoimmune and lung phenotypes, unlike the other novel loci, which have not been widely implicated. We evaluated DNER, KCNJ2, and SOX9 and found them to be expressed in human lung tissue. DNER and SOX9 further showed evidence of differential expression in human airway epithelium in smokers compared to non-smokers. Our findings demonstrated that joint testing of SNP and SNP-by-environment interaction identified novel loci associated with complex traits that are missed when considering only the genetic main effects