Anti-inflammatory reprogramming of microglia cells by metabolic modulators to counteract neurodegeneration; a new role for Ranolazine.

Microglia chronic activation is a hallmark of several neurodegenerative diseases, including the retinal ones, possibly contributing to their etiopathogenesis. However, some microglia sub-populations have anti-inflammatory and neuroprotective functions, thus making arduous deciphering the role of these cells in neurodegeneration. Since it has been proposed that functionally different microglia subsets also rely on different metabolic routes, we hypothesized that modulating microglia metabolism might be a tool to enhance their anti-inflammatory features. This would have a preventive and therapeutic potential in counteracting neurodegenerative diseases. For this purpose, we tested various molecules known to act on cell metabolism, and we revealed the anti-inflammatory effect of the FDA-approved piperazine derivative Ranolazine on microglia cells, while confirming the one of the flavonoids Quercetin and Naringenin, both in vitro and in vivo. We also demonstrated the synergistic anti-inflammatory effect of Quercetin and Idebenone, and the ability of Ranolazine, Quercetin and Naringenin to counteract the neurotoxic effect of LPS-activated microglia on 661W neuronal cells. Overall, these data suggest that using the selected molecules -also in combination therapies- might represent a valuable approach to reduce inflammation and neurodegeneration while avoiding long term side effects of corticosteroids.

Neuroprotective Nanoparticles Targeting the Retina: A Polymeric Platform for Ocular Drug Delivery Applications.

Neuroprotective drug delivery to the posterior segment of the eye represents a major challenge to counteract vision loss. This work focuses on the development of a polymer-based nanocarrier, specifically designed for targeting the posterior eye. Polyacrylamide nanoparticles (ANPs) were synthesised and characterised, and their high binding efficiency was exploited to gain both ocular targeting and neuroprotective capabilities, through conjugation with peanut agglutinin (ANP:PNA) and neurotrophin nerve growth factor (ANP:PNA:NGF). The neuroprotective activity of ANP:PNA:NGF was assessed in an oxidative stress-induced retinal degeneration model using the teleost zebrafish. Upon nanoformulation, NGF improved the visual function of zebrafish larvae after the intravitreal injection of hydrogen peroxide, accompanied by a reduction in the number of apoptotic cells in the retina. Additionally, ANP:PNA:NGF counteracted the impairment of visual behaviour in zebrafish larvae exposed to cigarette smoke extract (CSE). Collectively, these data suggest that our polymeric drug delivery system represents a promising strategy for implementing targeted treatment against retinal degeneration.

Systemic treatment with cigarette smoke extract affects zebrafish visual behaviour, intraocular vasculature morphology and outer segment phagocytosis.

Introduction: Cigarette smoking adversely affects multiple aspects of human health including eye disorders such as age-related macular degeneration, cataracts and dry eye disease. However, there remains a knowledge gap in how constituents of cigarette smoke affect vision and retinal biology. We used zebrafish to assess effects of short-term acute exposure to cigarette smoke extract (CSE) on visual behaviour and retinal biology. Methods: Zebrafish larvae with a developed visual system at three days post-fertilization (dpf) were exposed to CSE for 4, 24 or 48 hours. Visual behaviour, hyaloid vasculature morphology, retinal histology, oxidative stress gene expression and outer segment phagocytosis were investigated using visual behavioural optokinetic and visual motor response assays (OKR and VMR), microscopy (light, fluorescence and transmission electron microscopy), and real-time PCR. Results: In zebrafish larvae, 48 hours of CSE treatment resulted in significantly reduced visual behaviour. Larvae treated with 10, 15 or 20 µg/mL CSE showed an average of 13.7, 10.7 or 9.4 saccades per minute, respectively, significantly lower compared with 0.05% DMSO controls (p=0.0093, p=0.0004 and p<0.0001, respectively) that exhibited 19.7 saccades per minute. The diameter of intraocular vessels increased from 4.833 µm in 0.05% DMSO controls to 5.885 µm in the 20 µg/mL CSE-treated larvae (p=0.0333). Biometry analysis highlighted a significant axial length elongation in 20 µg/mL CSE-treated larvae (216.9 µm, p<0.0001) compared to 0.05% dimethyl sulfoxide (DMSO) controls (205.1 µm). Larvae exposed to 20 µg/mL CSE had significantly (p=0.0002) higher numbers of RPE phagosomes compared to vehicle controls (0.1425 and 0.093 phagosomes/µm RPE, respectively). Conclusions: Zebrafish larvae with a developed visual system display apparent defects in visual behaviour and retinal biology after acute exposure to CSE, establishing a valuable in vivo model to investigate ocular disorders related to cigarette smoke.

This study investigates the effects of cigarette smoke on the visual system of zebrafish larvae. We exposed the larvae to cigarette smoke extract for 4, 24, or 48 hours and assessed their eye movements, retina morphology and oxidative stress gene expression. Exposure to cigarette smoke extract for 48 hours reduced eye movements behaviour in the zebrafish larvae and led to changes in the morphology of their hyaloid vasculature present in the lens and the number of phagosomes in their retinal pigment epithelium. When exposure was shortened to 4 or 24 hours, eye movements were still reduced and oxidative stress was affected. These results suggest that zebrafish larvae can be used as a valuable model to investigate ocular disorders related to cigarette smoke.

A Model of a Zebrafish Avatar for Co-Clinical Trials.

Animal "avatars" and co-clinical trials are being developed for possible use in personalized medicine in oncology. In a co-clinical trial, the cancer cells of the patient's tumor are xenotransplanted into the animal avatar for drug efficacy studies, and the data collected in the animal trial are used to plan the best drug treatment in the patient trial. Zebrafish have recently been proposed for implementing avatar models, however the lack of a general criterion for the chemotherapy dose conversion from humans to fish is a limitation in terms of conducting co-clinical trials. Here, we validate a simple, reliant and cost-effective avatar model based on the use of zebrafish embryos. By crossing data from safety and efficacy studies, we found a basic formula for estimating the equivalent dose for use in co-clinical trials which we validated in a clinical study enrolling 24 adult patients with solid cancers (XenoZ, NCT03668418).

Kidney and liver involvement in cryoglobulinemia.

Cryoglobulinemia is a pathological condition characterized by the presence in the blood of a group of proteins (cryoglobulins) showing the common property of precipitating from cooled serum. Mixed cryoglobulins (MCs) are composed of a polyclonal immunoglobulin G (IgG) bound to another immunoglobulin that acts as an anti-IgG rheumatoid factor; 2 types of MCs can be identified. The origin is not clear in 30% of all MCs, and this subset of cryoglobulinemias is called "essential." The great majority (up to 90%) of patients with essential MC (EMC) of both types has been related to HCV infection. The renal involvement in essential MC has been observed in 2% to 50% of patients in reported series. A well-characterized pattern of glomerular disease termed "cryoglobulinemic glomerulonephritis" is present in individuals with type-II EMCs in serum and IgMk RF being the most frequent monoclonal component. Aspecific and infrequent glomerular lesions occur in EMC patients with type III cryoglobulins. The most frequent histologic picture of cryoglobulinemic GN is that of membranoproliferative GN (MPGN) with subendothelial deposits. However, cryoglobulinemic GN may have some distinctive features that differentiate it from idiopathic type-I MPGN. Evidence of liver involvement has been found in 60% to 80% of EMC patients. Recent data support the notion that the stage of liver disease in patients with type II or III MC has association with the prevalence of cryoglobulinemia. Few controlled trials have been published on the treatment of HCV-related MC; in addition, the majority of the patients enrolled in these trials had an unclear renal involvement. Interferon (IFN) is an effective drug for the treatment of patients with HCV-associated MC and cryoglobulinemic GN. In the presence of acute cryoglobulinemic GN, IFN does not prevent progression of renal damage; combination therapy with cytotoxic ad anti-inflammatory drugs, and sometimes plasma exchange, is recommended. Prospective controlled trials are underway on this purpose.

Outcome of peritoneal dialysis in cirrhotic patients with chronic renal failure.

BACKGROUND: Results of peritoneal dialysis (PD) in cirrhotic patients with renal failure are debated. The aim of the present study is to assess the outcome of PD patients with liver cirrhosis. METHODS: A retrospective study based on clinical records was performed in 21 cirrhotic and 41 PD patients without liver disease followed up at our PD unit. RESULTS: Five-year patient and technique survival were similar in the two groups. Seven cirrhotic patients (33%) died of liver failure (5 patients), liver cancer (1 patient), and peritonitis (1 patient). Ten controls (24%) died of cardiovascular complications (6 patients), pneumonia (1 patient), cachexia (1 patient), and unknown reasons (2 patients). Six cirrhotic patients discontinued PD therapy after 44.3 +/- 24.7 months because of inadequate dialysis (2 patients), sclerosing peritonitis (2 patients), dementia (1 patient), or patient choice (1 patient). Twelve controls discontinued PD therapy after 33 +/- 25.9 months because of peritonitis (6 patients), exit-site infection (1 patient), inadequate peritoneal clearance (3 patients), catheter malfunction (1 patient), and patient request (1 patient). The peritonitis rate was 0.31 episodes/y in cirrhotic patients and 0.53 episodes/y in controls (P = not significant). The hospitalization rate was similar (16.5 d/y in cirrhotic patients, 15.4 d/y in controls). In cirrhotic patients, complications were leakage (3 patients), symptomatic hypotension (5 patients), anemia (5 patients), severe malnutrition (14 patients), sclerosing peritonitis (2 patients), and hepatic encephalopathy (3 patients). CONCLUSION: The outcome of PD and risk for bacterial peritonitis or other dialysis complications are not worsened by the presence of liver cirrhosis.