Autosomic dominant polycystic kidney disease and metformin: Old knowledge and new insights on retarding progression of chronic kidney disease.

Autosomal dominant polycystic kidney disease (ADPKD) is the most common congenital kidney disorder, generally caused by mutations in the PKD1 and PKD2 genes, coding for polycystins 1 and 2. Its pathogenesis is accompanied by alterations of the cAMP, mTOR, MAPK/ERK, and JAK/STAT pathways. ADPKD is clinically characterized by the formation of many growing cysts with kidney enlargement and a progressive damage to the parenchyma, up to its complete loss of function, and the onset of end-stage renal disease (ESRD). The current aim of ADPKD therapy is the inhibition of cyst development and retardation of chronic kidney disease progression. Several drugs have been recently included as potential therapies for ADPKD including metformin, the drug of choice for the treatment of type 2 diabetes mellitus, according to its potential inhibitory effects on cystogenesis. In this review, we summarize preclinical and clinical evidence endorsing or rejecting metformin administration in ADPKD evolution and pathological mechanisms. We explored the biology of APDKD and the role of metformin in slowing down cystogenesis searching PubMed and Clinical Trials to identify relevant data from the database inception to December 2020. From our research analysis, evidence for metformin as emerging cure for ADPKD mainly arise from preclinical studies. In fact, clinical studies are still scanty and stronger evidence is awaited. Its effects are likely mediated by inhibition of the ERK pathway and increase of AMPK levels, which are both linked to ADPKD pathogenesis.

Correction to: An open-label, randomized, placebo-controlled study on the effectiveness of a novel probiotics administration protocol (ProbiotiCKD) in patients with mild renal insufficiency (stage 3a of CKD).

In the original publication of the article, few of the authors were missed in the author group.

An open-label, randomized, placebo-controlled study on the effectiveness of a novel probiotics administration protocol (ProbiotiCKD) in patients with mild renal insufficiency (stage 3a of CKD).

PURPOSE: Gut dysbiosis has been described in advanced, but not in initial stages of CKD. Considering the relevant impact of gut dysbiosis on renal and cardiovascular risk, its diagnosis and treatment are clinically relevant. METHODS: We designed, open-label, placebo-controlled intervention study (ProbiotiCKD) to evaluate gut microbiota metabolism in a cohort of KDIGO CKD patients (n = 28) at baseline and after a randomly assigned treatment with probiotics or placebo. Gut microbiota status was evaluated on:. RESULTS: Basal mean fecal Lactobacillales and Bifidobacteria concentrations were abnormally low in both groups, while urinary indican and 3-MI levels were, indicating a mixed (fermentative and putrefactive) dysbiosis. After treatment, mean fecal Lactobacillales and Bifidobacteria concentrations were increased, only in the probiotics group (p < 0.001). Conversely, mean urinary indican and 3-MI levels only in the group treated with probiotics (p < 0.001). Compared to placebo group, significant improvements of C-reactive protein (p < 0.001), iron (p < 0.001), ferritin (p < 0.001), transferrin saturation (p < 0.001), ß2-microglobulin (p < 0.001), serum iPTH and serum calcium were observed only in the probiotics group. CONCLUSIONS: ProbiotiCKD is the first intervention study demonstrating that an intestinal mixed dysbiosis is present even in early CKD stage and can be effectively corrected by the novel mode of administration of high-quality probiotics with improvement of inflammatory indices, iron status and iPTH stabilization.

GM1 gangliosidosis and Morquio B disease: an update on genetic alterations and clinical findings.

GM1 gangliosidosis and Morquio B syndrome, both arising from beta-galactosidase (GLB1) deficiency, are very rare lysosomal storage diseases with an incidence of about 1:100,000-1:200,000 live births worldwide. Here we report the beta-galactosidase gene (GLB1) mutation analysis of 21 unrelated GM1 gangliosidosis patients, and of 4 Morquio B patients, of whom two are brothers. Clinical features of the patients were collected and compared with those in literature. In silico analyses were performed by standard alignments tools and by an improved version of GLB1 three-dimensional models. The analysed cohort includes remarkable cases. One patient with GM1 gangliosidosis had a triple X syndrome. One patient with juvenile GM1 gangliosidosis was homozygous for a mutation previously identified in Morquio type B. A patient with infantile GM1 gangliosidosis carried a complex GLB1 allele harbouring two genetic variants leading to p.R68W and p.R109W amino acid changes, in trans with the known p.R148C mutation. Molecular analysis showed 27 mutations, 9 of which are new: 5 missense, 3 microdeletions and a nonsense mutation. We also identified four new genetic variants with a predicted polymorphic nature that was further investigated by in silico analyses. Three-dimensional structural analysis of GLB1 homology models including the new missense mutations and the p.R68W and p.R109W amino acid changes showed that all the amino acid replacements affected the resulting protein structures in different ways, from changes in polarity to folding alterations. Genetic and clinical associations led us to undertake a critical review of the classifications of late-onset GM1 gangliosidosis and Morquio B disease.