4-Phenylbutyric Acid Treatment Reduces Low-Molecular-Weight Proteinuria in a Clcn5 Knock-in Mouse Model for Dent Disease-1.

Dent disease-1 (DD-1) is a rare X-linked tubular disorder characterized by low-molecular-weight proteinuria (LMWP), hypercalciuria, nephrolithiasis and nephrocalcinosis. This disease is caused by inactivating mutations in the CLCN5 gene which encodes the voltage-gated ClC-5 chloride/proton antiporter. Currently, the treatment of DD-1 is only supportive and focused on delaying the progression of the disease. Here, we generated and characterized a Clcn5 knock-in mouse model that carries a pathogenic CLCN5 variant, c. 1566_1568delTGT; p.Val523del, which has been previously detected in several DD-1 unrelated patients, and presents the main clinical manifestations of DD-1 such as high levels of urinary b2-microglobulin, phosphate and calcium. Mutation p.Val523del causes partial ClC-5 retention in the endoplasmic reticulum. Additionally, we assessed the ability of sodium 4-phenylbutyrate, a small chemical chaperone, to ameliorate DD-1 symptoms in this mouse model. The proposed model would be of significant value in the investigation of the fundamental pathological processes underlying DD-1 and in the development of effective therapeutic strategies for this rare condition.

Characterization of pre-mRNA Splicing Defects Caused by CLCN5 and OCRL Mutations and Identification of Novel Variants Associated with Dent Disease.

Dent disease (DD) is an X-linked renal tubulopathy characterized by low-molecular-weight proteinuria, hypercalciuria, nephrocalcinosis, nephrolithiasis and progressive renal failure. Two-thirds of cases are associated with inactivating variants in the CLCN5 gene (Dent disease 1, DD1) and a few present variants in the OCRL gene (Dent disease 2, DD2). The aim of the present study was to test the effect on the pre-mRNA splicing process of DD variants, described here or in the literature, and describe the clinical and genotypic features of thirteen unrelated patients with suspected DD. All patients presented tubular proteinuria, ten presented hypercalciuria and five had nephrolithiasis or nephrocalcinosis. CLCN5 and OCRL genes were analyzed by Sanger sequencing. Nine patients showed variants in CLCN5 and four in OCRL; eight of these were new. Bioinformatics tools were used to select fifteen variants with a potential effect on pre-mRNA splicing from our patients' group and from the literature, and were experimentally tested using minigene assays. Results showed that three exonic missense mutations and two intronic variants affect the mRNA splicing process. Our findings widen the genotypic spectrum of DD and provide insight into the impact of variants causing DD.

Circulating miR-1246 in the Progression of Chronic Obstructive Pulmonary Disease (COPD) in Patients from the BODE Cohort.

Background: COPD is characterized by a persistent inflammatory response, especially against cigarette smoke. COPD patients may develop varying degrees of emphysematous destruction of the lungs. A pathophysiological role for miRNAs in COPD has been suggested in several studies. We examined changes in microRNAs expression profile during 10 years follow-up in relation to COPD progression. Methods: Clinical and lung function parameters were registered from every subject included in the study. miRNAs expression was determined in 14 serum samples from 7 patients in two moments (4 smokers with COPD (BODE cohort) and 3 smokers without COPD) by next generation sequencing (NGS) at baseline and after 10 years follow-up. A validation study was performed by qPCR in 20 patients with COPD (13 emphysema-diagnosed by CTscan) and 10 smoker controls at baseline and after 10 years follow-up. hsa-miRNA-20a-5p and hsa-let-7d-5p were used as endogenous controls. Results: A total of 198 miRNAs (≥10TPM) were identified by NGS. Between these, hsa-miR-1246 was found significantly downregulated in COPD patients after 10 years when compared to baseline (p<0.0001, FDR=0.05). Seventy-five percent of these patients had an emphysema diagnose. In the validation analysis, when analyzed longitudinally, hsa-miR-1246 was significantly downregulated in COPD patients with emphysema after 10 years (p= 0.019). However, no association was found between the expression of miR-1246 and any other lung function parameters (FEV1, PaO2, DLCO, IC/TLC) within the follow-up period. GO and KEGG enrichment analysis revealed miR-1246 to be associated with target genes in several pathways involved in COPD/emphysema development. Conclusion: Our findings suggest that hsa-miR-1246 may act as a biomarker of emphysema in COPD. Functional analysis is guaranteed to elucidate its role in COPD.

In Vitro Evaluation of Combined Commercialized Ophthalmic Solutions Against Acanthamoeba Strains.

Acanthamoeba is a free-living amoebae genus which is present worldwide in natural and artificial environments. These amoebae are clinically important as causative agents of diseases in humans and other animals such as a fatal encephalitis or a sight threatening Acanthamoeba keratitis (AK). Lately; studies have focused on the search of novel therapeutic options for AK but also to prevent infections. Furthermore; the evaluation of commercialized products seems to be an option for this case since not clinical assays would be required. Thus; we aimed to test the amoebicidal activity of different mixtures of two commercial ophthalmic solutions: Systane® Ultra; which has already shown anti-Acanthamoeba properties; and Naviblef® Daily Care. In addition, we tested their cytotoxic effect against murine macrophages. At the individual level; Naviblef® Daily Care showed to be the most active product against Acanthamoeba spp. Nevertheless; the combinations of Systane® Ultra and Naviblef® Daily Care; showed an improvement in the activity against trophozoites and cysts of Acanthamoeba castellanii Neff. Moreover; the concentration necessary to generate cytotoxic effect against murine macrophages (J774.1) was much higher than the required for the amoebicidal and cysticidal effect achieved in the most effective mixtures.