Atrial Natriuretic Peptide Acts as a Neuroprotective Agent in in Vitro Models of Parkinson’s Disease via Up-regulation of the Wnt/β-Catenin Pathway

In the last decades increasing evidence indicated a crucial role of the Wnt/β-catenin signaling in development of midbrain dopaminergic (mDA) neurons. Recently dysregulation of this pathway has been proposed as a novel pathomechanism leading to Parkinson’s disease (PD) and some of the molecules participating to the signaling have been evaluated as potential therapeutic targets for PD. Atrial natriuretic peptide (ANP) is a cardiac-derived hormone having a critical role in cardiovascular homeostasis. ANP and its receptors (NPRs) are widely expressed in mammalian central nervous system (CNS) where they could be implicated in the regulation of neural development, synaptic transmission and information processing, as well as in neuroprotection. Until now, the effects of ANP in the CNS have been mainly ascribed to the binding and activation of NPRs. We have previously demonstrated that ANP affects the Wnt/β-catenin signaling in colorectal cancer cells through a Frizzled receptor-mediated mechanism. The purpose of this study was to investigate if ANP is able to exert neuroprotective effect on two in vitro models of PD, and if this effect could be related to activation of the Wnt/β-catenin signaling. As cellular models of DA neurons, we used the proliferating or RA-differentiated human neuroblastoma cell line SH-SY5Y. In both DA neuron-like cultures, ANP is able to positively affect the Wnt/β-catenin signaling, by inducing β-catenin stabilization and nuclear translocation. Importantly, activation of the Wnt pathway by ANP exerts neuroprotective effect when these two cellular systems were subjected to neurotoxic insult (6-OHDA) for mimicking the neurodegeneration of PD. Our data support the relevance of exogenous ANP as an innovative therapeutic molecule for midbrain, and more in general for brain diseases for which aberrant Wnt signaling seems to be involved

Natriuretic peptides are neuroprotective on in vitro models of PD and promote dopaminergic differentiation of hiPSCs-derived neurons via the Wnt/β-catenin signaling

Abstract Over the last 20 years, the efforts to develop new therapies for Parkinson’s disease (PD) have focused not only on the improvement of symptomatic therapy for motor and non-motor symptoms but also on the discovering of the potential causes of PD, in order to develop disease-modifying treatments. The emerging role of dysregulation of the Wnt/β-catenin signaling in the onset and progression of PD, as well as of other neurodegenerative diseases (NDs), renders the targeting of this signaling an attractive therapeutic opportunity for curing this brain disorder. The natriuretic peptides (NPs) atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP), are cardiac and vascular-derived hormones also widely expressed in mammalian CNS, where they seem to participate in numerous brain functions including neural development/differentiation and neuroprotection. We recently demonstrated that ANP affects the Wnt/β-catenin pathway possibly through a Frizzled receptor-mediated mechanism and that it acts as a neuroprotective agent in in vitro models of PD by upregulating this signaling. Here we provide further evidence supporting the therapeutic potential of this class of natriuretic hormones. Specifically, we demonstrate that all the three natriuretic peptides are neuroprotective for SHSY5Y cells and primary cultures of DA neurons from mouse brain, subjected to neurotoxin insult with 6-hydroxydopamine (6-OHDA) for mimicking the neurodegeneration of PD, and these effects are associated with the activation of the Wnt/β-catenin pathway. Moreover, ANP, BNP, CNP are able to improve and accelerate the dopaminergic differentiation and maturation of hiPSCs-derived neural population obtained from two differed healthy donors, concomitantly affecting the canonical Wnt signaling. Our results support the relevance of exogenous ANP, BNP, and CNP as attractive molecules for both neuroprotection and neurorepair in PD, and more in general, in NDs for which aberrant Wnt signaling seems to be the leading pathogenetic mechanism

The Stability of Gahnite Doped with Chromium Pigments in Glazes from the French Manufacture of Sèvres

International audienceThe French manufacture of Sèvres, famous for its production of fine porcelain artefacts, has been synthesizing pink pigments mainly composed of the spinel phase ZnAl 2−x Cr x O 4 with x varying from 0.25 to 0.41 since the middle of the 19 th century. This kind of pigment is mixed with an uncolored frit to obtain decorations for porcelain artefacts. However, the pink color of 2 the pigment is altered in a particular uncolored frit and a brownish color appears. The mechanism of this color change was investigated. Observations under a scanning electron microscope revealed the formation of a phase rich in Cr resulting from reactions between the uncolored frit and the pigment during firing. X-Ray Diffraction combined with Rietveld refinements and X-Ray Absorption Near Edge Structure at the Cr K-edge measurements showed that the new formed phase belongs to the same spinel phase ZnAl 2−x Cr x O 4 than the pigment, but with a higher Cr content x. We showed that its formation and thus the stability of the pigment is driven by the Al content in the uncolored frit

Radiofrequency Ablation of Small Hepatocellular Carcinoma in Cirrhotic Patients Awaiting Liver Transplantation: A Prospective Study

OBJECTIVE: Determine the histologic response-rate (complete versus partial tumor extinction) after single radiofrequency ablation (RFA) of small hepatocellular carcinoma (HCC) arising in cirrhosis. Investigate possible predictors of response and assess efficacy and safety of RFA as a bridge to liver transplantation (OLT). BACKGROUND: RFA has become the elective treatment of local control of HCC, although histologic data supporting radiologic assessment of response are rare and prospective studies are lacking. Prognostic impact of repeated RFA for HCC persistence is also undetermined. METHODS: Percentage of RFA-induced necrosis and tumor persistence-rate at various intervals from treatment was studied in 60 HCC (median: 3 cm; Milan-Criteria IN: 80%) isolated in 50 consecutive cirrhotic patients undergoing OLT. Single-session RFA was the only treatment planned before OLT. Histologic response determined on explanted livers was related to 28 variables and to pre-OLT CT scan. RESULTS: Mean interval RFA→OLT was 9.5 months. Post-RFA complete response rate was 55%, rising to 63% for HCC ≤3 cm. Tumor size was the only prognostic factor significantly related to response (P = 0.007). Tumor satellites and/or new HCC foci (56 nodules) were unaffected by RFA and significantly correlated with HCC >3 cm (P = 0.05). Post-RFA tumor persistence probability increased with time (12 months: 59%; 18 months: 70%). Radiologic response rate was 70%, not significantly different from histology. Major post-RFA morbidity was 8%. No mortality, Child deterioration, patient withdrawal because of tumor progression was observed. Post-OLT 3-year patient/graft survival was 83%. CONCLUSIONS: RFA is a safe and effective treatment of small HCC in cirrhotics awaiting OLT, although tumor size (>3 cm) and time from treatment (>1 year) predict a high risk of tumor persistence in the targeted nodule. RFA should not be considered an independent therapy for HCC