YO Nanoparticles and X-ray Radiation-Induced Effects in Melanoma Cells.

The innovative strategy of using nanoparticles in radiotherapy has become an exciting topic due to the possibility of simultaneously improving local efficiency of radiation in tumors and real-time monitoring of the delivered doses. Yttrium oxide (YO) nanoparticles (NPs) are used in material science to prepare phosphors for various applications including X-ray induced photodynamic therapy and in situ nano-dosimetry, but few available reports only addressed the effect induced in cells by combined exposure to different doses of superficial X-ray radiation and nanoparticles. Herein, we analyzed changes induced in melanoma cells by exposure to different doses of X-ray radiation and various concentrations of YO NPs.

Novel Dent disease 1 cellular models reveal biological processes underlying ClC-5 loss-of-function.

Dent disease 1 (DD1) is a rare X-linked renal proximal tubulopathy characterized by low molecular weight proteinuria and variable degree of hypercalciuria, nephrocalcinosis and/or nephrolithiasis, progressing to chronic kidney disease. Although mutations in the electrogenic Cl-/H+ antiporter ClC-5, which impair endocytic uptake in proximal tubule cells, cause the disease, there is poor genotype-phenotype correlation and their contribution to proximal tubule dysfunction remains unclear. To further discover the mechanisms linking ClC-5 loss-of-function to proximal tubule dysfunction, we have generated novel DD1 cellular models depleted of ClC-5 and carrying ClC-5 mutants p.

EDEM3 Domains Cooperate to Perform Its Overall Cell Functioning.

EDEM3 recognizes and directs misfolded proteins to the ER-associated protein degradation (ERAD) process. EDEM3 was predicted to act as lectin or as a mannosidase because of its homology with the GH47 catalytic domain of the Man1B1, but the contribution of the other regions remained unresolved. Here, we dissect the molecular determinants governing EDEM3 function and its cellular interactions.

New factors for protein transport identified by a genome-wide CRISPRi screen in mammalian cells.

Protein and membrane trafficking pathways are critical for cell and tissue homeostasis. Traditional genetic and biochemical approaches have shed light on basic principles underlying these processes. However, the list of factors required for secretory pathway function remains incomplete, and mechanisms involved in their adaptation poorly understood.

Sodium channel TRPM4 and sodium/calcium exchangers (NCX) cooperate in the control of Ca-induced mucin secretion from goblet cells.

Regulated mucin secretion is essential for the formation of the mucus layer that protects the underlying epithelial cells from foreign particles. Alterations in the quantity or quality of secreted mucins are therefore detrimental to airway and colon physiology. Based on various biochemical assays in several human cell lines, we report here that Na/Ca exchanger 2 (NCX2) works in conjunction with transient receptor potential cation channel subfamily M member 4 (TRPM4), and perhaps TRPM5, Na channels to control Ca-mediated secretion of both mucin 2 (MUC2) and MUC5AC from HT29-18N2 colonic cancer cells.

KChIP3 coupled to Ca oscillations exerts a tonic brake on baseline mucin release in the colon.

Unlabelled: Regulated mucin secretion from specialized goblet cells by exogenous agonist-dependent (stimulated) and -independent (baseline) manner is essential for the function of the epithelial lining. Over extended periods, baseline release of mucin can exceed quantities released by stimulated secretion, yet its regulation remains poorly characterized. We have discovered that ryanodine receptor-dependent intracellular Ca oscillations effect the dissociation of the Ca-binding protein, KChIP3, encoded by gene, from mature mucin-filled secretory granules, allowing for their exocytosis.

Inhibition of N-glycan processing modulates the network of EDEM3 interactors.

We present here data on EDEM3 network of ER resident interactors and the changes induced upon this network by perturbing the early ER N-glycan processing with mannosidase and glucosidase inhibitors. By coupling immunoprecipitation with mass spectrometry we identified EDEM3 interactors and assigned statistical significance to those most abundant ER-residents that might form functional complexes with EDEM3. We further show that this ER interaction network changes in both content and abundance upon treatment with kifunensine (kif) and N-butyldeoxynojirimycin (NB-DNJ) which suggests that when interfering with the N-glycan processing pathway, the functional complexes involving EDEM3 adapt to maintain the cellular homeostasis.