Acidic Compartment Size, Positioning, and Function during Myogenesis and Their Modulation by the Wnt/Beta-Catenin Pathway.

Lysosomes and acidic compartments are involved in breaking down of macromolecules, membrane recycling, and regulation of signaling pathways. Here, we analyzed the role of acidic compartments during muscle differentiation and the involvement of the Wnt/beta-catenin pathway in lysosomal function during myogenesis. Acridine orange was used to localize and quantify acidic cellular compartments in primary cultures of embryonic muscle cells from Gallus gallus. Our results show an increase in acidic compartment size and area, as well as changes in their positioning during the initial steps of myogenesis. The inhibition of lysosomal function by either the chloroquine Lys05 or the downregulation of LAMP-2 with siRNA impaired chick myogenesis, by inhibiting myoblast fusion. Two activators of the Wnt/beta-catenin pathway, BIO and Wnt3a, were able to rescue the inhibitory effects of Lys05 in myogenesis. These results suggest a new role for the Wnt/beta-catenin pathway in the regulation of acidic compartment size, positioning, and function in muscle cells.

Neutrophil Extracellular Traps (NETs) Promote Pro-Metastatic Phenotype in Human Breast Cancer Cells through Epithelial-Mesenchymal Transition.

Neutrophil extracellular traps (NETs) have been associated with several steps of tumor progression, including primary growth and metastasis. One of the key features for the acquisition of the metastatic ability is the epithelial-mesenchymal transition (EMT), a complex cellular program. In this study, we evaluated the ability of isolated NETs in modulating the pro-metastatic phenotype of human breast cancer cells. Tumor cells were treated with isolated NETs and then samples were generated for cell migration, quantitative RT-PCR, western blotting, immunofluorescence, and flow cytometry assays. RNA-seq data from The Cancer Genome Atlas (TCGA) database were assessed. NETs changed the typical epithelial morphology of MCF7 cells into a mesenchymal phenotype, a process that was accompanied by enhanced migratory properties. Additional EMT traits were observed: increased expression of N-cadherin and fibronectin, while the E-cadherin expression was repressed. Notably, NETs positively regulated the gene expression of several factors linked to the pro-inflammatory and pro-metastatic properties. Analyses of TCGA data showed that samples from breast cancer patients exhibit a significant correlation between pro-tumoral and neutrophil signature gene expression, including several EMT and pro-metastatic factors. Therefore, NETs drive pro-metastatic phenotype in human breast cancer cells through the activation of the EMT program.

HPLC determination of dexamethasone in human plasma and its application to an in vitro release study from endovascular stents.

A simple, accurate and precise HPLC assay was developed and validated for determination of dexamethasone in human plasma. Triamcinolone acetonide was used as internal standard (I.S.) and plasma samples were extracted using liquid-liquid extraction with ethyl acetate. Chromatography was performed on a C-18 column with acetonitrile-triple distilled water (28:72% v/v, pH adjusted to 2.3 with phosphoric acid) at a flow rate of 1.2 mL/min and detection wavelength 254 nm. The assay was linear at a concentration range of 0.25-6 microg/mL with recoveries >77%. Precision and accuracy were within the acceptable limits. The method was used to determine dexamethasone release from different material coated endoluminal vascular stents in in vitro human plasma experiments. The results were useful in identifying a good coating material for the stents.

Familial flexion-supination deformity at the PIP joint of the finger.

The case of a 36-year-old female typist with familial bilateral flexion-supination deformity at the PIP joint of the long fingers is presented. This deformity was ascribed to hypoplasia of the radial lateral band and retaining structures of the long extensor tendon. The deformity was corrected by bridging the second dorsal interosseous muscle and the radial extensor lateral band with a free tendon graft and the reconstruction of retaining ligaments.