Dystrophin-deficient dogs with reduced myostatin have unequal muscle growth and greater joint contractures

Abstract Background Myostatin (Mstn) is a negative regulator of muscle growth whose inhibition promotes muscle growth and regeneration. Dystrophin-deficient mdx mice in which myostatin is knocked out or inhibited postnatally have a less severe phenotype with greater total mass and strength and less fibrosis and fatty replacement of muscles than mdx mice with wild-type myostatin expression. Dogs with golden retriever muscular dystrophy (GRMD) have previously been noted to have increased muscle mass and reduced fibrosis after systemic postnatal myostatin inhibition. Based partly on these results, myostatin inhibitors are in development for use in human muscular dystrophies. However, persisting concerns regarding the effects of long-term and profound myostatin inhibition will not be easily or imminently answered in clinical trials. Methods To address these concerns, we developed a canine (GRippet) model by crossbreeding dystrophin-deficient GRMD dogs with Mstn-heterozygous (Mstn +/−) whippets. A total of four GRippets (dystrophic and Mstn +/−), three GRMD (dystrophic and Mstn wild-type) dogs, and three non-dystrophic controls from two litters were evaluated. Results Myostatin messenger ribonucleic acid (mRNA) and protein levels were downregulated in both GRMD and GRippet dogs. GRippets had more severe postural changes and larger (more restricted) maximal joint flexion angles, apparently due to further exaggeration of disproportionate effects on muscle size. Flexors such as the cranial sartorius were more hypertrophied on magnetic resonance imaging (MRI) in the GRippets, while extensors, including the quadriceps femoris, underwent greater atrophy. Myostatin protein levels negatively correlated with relative cranial sartorius muscle cross-sectional area on MRI, supporting a role in disproportionate muscle size. Activin receptor type IIB (ActRIIB) expression was higher in dystrophic versus control dogs, consistent with physiologic feedback between myostatin and ActRIIB. However, there was no differential expression between GRMD and GRippet dogs. Satellite cell exhaustion was not observed in GRippets up to 3 years of age. Conclusions Partial myostatin loss may exaggerate selective muscle hypertrophy or atrophy/hypoplasia in GRMD dogs and worsen contractures. While muscle imbalance is not a feature of myostatin inhibition in mdx mice, findings in a larger animal model could translate to human experience with myostatin inhibitors

Analysis of β-nerve growth factor and its precursor during human pregnancy by immunoaffinity-liquid chromatography tandem mass spectrometry

Abstract β-Nerve growth factor (NGF) is a neurotrophin that plays a critical role in fetal development during gestation. ProNGF is the precursor form of NGF with a distinct biological profile. In order to investigate the role of NGF and proNGF in pregnant human females, a sensitive and selective immunoaffinity liquid chromatography-tandem mass spectrometry assay was developed and qualified to simultaneously measure the levels of total NGF (tNGF; sum of mature and proNGF) and proNGF using full and relative quantification strategies, respectively. The assay was used to determine serum tNGF and proNGF levels in the three gestational trimesters of pregnancy and in non-pregnant female controls. Mean tNGF ± SD were 44.6 ± 12.3, 42.6 ± 9.3, 65.4 ± 17.6 and 77.0 ± 17.8 pg/mL for non-pregnant, first, second, and third trimesters, respectively, demonstrating no significant increase in circulating tNGF between the control and the first trimester, and a moderate yet significant 1.7-fold increase through gestation. proNGF levels during the first trimester were unchanged compared to control. In contrast to tNGF, however, proNGF levels during gestation remained stable without significant changes. The development of this sensitive, novel immunoaffinity duplexed assay for both tNGF and proNGF is expected to enable further elucidation of the roles these neurotrophins play in human pregnancy as well as other models

Highly Specific and Sensitive Measurements of Human and Monkey Interleukin 21 Using Sequential Protein and Tryptic Peptide Immunoaffinity LC-MS/MS

A highly specific and sensitive immunoaffinity LC-MS/MS assay for quantification of human and cynomolgus monkey interleukin 21 (IL-21) was developed, qualified, and implemented. The workflow includes offline enrichment of IL-21 using an anti-IL-21 capture antibody, followed by isolation using magnetic beads, trypsin digestion, online enrichment of IL-21 derived tryptic peptides using antipeptide antibodies, and quantification using nanoflow LC-MS/MS. This assay was developed and qualified in human and cynomolgus monkey serum and tissues with a lower limit of quantitation of 0.78 pg/mL based on the intact cytokine. Both intra- and interbatch precision and accuracy, as well as stability and recovery, were found to be acceptable. IL-21 was not detected in serum from normal healthy volunteers or from autoimmune disease patients. However, IL-21 levels were quantified in cynomolgus monkey spleen and colon tissue and normal and inflammatory bowel disease (IBD) human colon tissue as well as hyperplasia human tonsils

The pharmacotherapy of the venous thromboembolism

Topic: Treatment of venous thromboembolism Author: Pavla Hanzlíková Venous thromboembolism is the designation for the states in which a new rising thrombus in the peripheral venous bloodstream can reach the pulmonary artery. These include deep vein thrombosis or phlebothrombosis legs and pulmonary embolism. Clinically, this is absolutely a different disease, but which are closely related and often occur together and have the same treatment. Anticoagulants, fibrinolytic, antiplatelet therapy with adenosine diphosphate receptor blockers, inhibitors of platelet glycoprotein receptor IIb / IIIa and venous medication are used in the treatment of thromboembolic disease. An important part of therapy are non- pharmacological approaches. Another promising treatment procedures are in a clinical testing

Additional file 5: of Dystrophin-deficient dogs with reduced myostatin have unequal muscle growth and greater joint contractures

Figure S2. Pax7-positive cells in Mstn +/+ and Mstn +/− GRMD/GRippet and GRMD-carrier dogs. Laminin (A), Pax7 (B), DAPI (C), and merged (D) staining are seen. Satellite cells were defined as Pax7+ nuclei within the laminin + basal lamina (also see data in Additional file 4: Table S3). (TIF 915 kb

IL1RL1 asthma risk variants regulate airway type 2 inflammation.

Genome-wide association studies of asthma have identified genetic variants in the IL1RL1 gene, but the molecular mechanisms conferring risk are unknown. IL1RL1 encodes the ST2 receptor (ST2L) for IL-33 and an inhibitory decoy receptor (sST2). IL-33 promotes type 2 inflammation, which is present in some but not all asthmatics. We find that two single nucleotide polymorphisms (SNPs) in IL1RL1 - rs1420101 and rs11685480 - are strongly associated with plasma sST2 levels, though neither is an expression quantitative trait locus (eQTL) in whole blood. Rather, rs1420101 and rs11685480 mark eQTLs in airway epithelial cells and distal lung parenchyma, respectively. We find that the genetically determined plasma sST2 reservoir, derived from the lung, neutralizes IL-33 activity, and these eQTL SNPs additively increase the risk of airway type 2 inflammation among asthmatics. These risk variants define a population of asthmatics at risk of IL-33-driven type 2 inflammation