FGF signaling deregulation is associated with early developmental skeletal defects in animal models for mucopolysaccharidosis type II (MPSII).

Skeletal abnormalities represent a major clinical burden in patients affected by the lysosomal storage disorder mucopolysaccharidosis type II (MPSII, OMIM #309900). While extensive research has emphasized the detrimental role of stored glycosaminoglycans (GAGs) in the bone marrow (BM), a limited understanding of primary cellular mechanisms underlying bone defects in MPSII has hampered the development of bone-targeted therapeutic strategies beyond enzyme replacement therapy (ERT). We here investigated the involvement of key signaling pathways related to the loss of iduronate-2-sulfatase activity in two different MPSII animal models, D. rerio and M. musculus. We found that FGF pathway activity is impaired during early stages of bone development in IDS knockout mice and in a newly generated Ids mutant fish. In both models the FGF signaling deregulation anticipated a slow but progressive defect in bone differentiation, regardless of any extensive GAGs storage. We also show that MPSII patient fibroblasts harboring different mutations spanning the IDS gene exhibit perturbed FGF signaling-related markers expression. Our work opens a new venue to discover possible druggable novel key targets in MPSII.

Perturbations in cell signaling elicit early cardiac defects in mucopolysaccharidosis type II.

Morphogens release and activity can be negatively affected by an impaired glycosaminoglycans (GAGs) turnover and proteoglycans assembly in the extracellular matrix, leading to altered tissue morphogenesis. In this work, we show that loss of Iduronate-2-sulfatase (IDS) activity, affecting GAGs catabolism and responsible for a life-threatening valvulopathy in mucopolysaccharidosis type II (MPSII), triggers early Sonic Hedgehog (Shh) and Wnt/ß-catenin signaling defects, leading to aberrant heart development and atrioventricular valve formation in a zebrafish model. In addition, we consistently found impaired Shh signaling activity and cardiac electrophysiological abnormalities in IDS knockout mice at postnatal stages before any evident massive GAGs accumulation. These results suggest that IDS activity substantially affect cardiac morphogenesis through impaired Shh signaling and document an unexplored role of the enzyme in the fine-tuning of cell signaling pathways.

Browning Effects of a Chronic Pterostilbene Supplementation in Mice Fed a High-Fat Diet.

Obesity and related comorbidities are a major health concern. The drugs used to treat these conditions are largely inadequate or dangerous, and a well-researched approach based on nutraceuticals would be highly useful. Pterostilbene (Pt), i.e., 3,5-dimethylresveratrol, has been reported to be effective in animal models of obesity, acting on different metabolic pathways. We investigate here its ability to induce browning of white adipose tissue. Pt (5 µM) was first tested on 3T3-L1 mature adipocytes, and then it was administered (352 µmol/kg/day) to mice fed an obesogenic high-fat diet (HFD) for 30 weeks, starting at weaning. In the cultured adipocytes, the treatment elicited a significant increase of the levels of Uncoupling Protein 1 (UCP1) protein-a key component of thermogenic, energy-dissipating beige/brown adipocytes. In vivo administration antagonized weight increase, more so in males than in females. Analysis of inguinal White Adipose Tissue (WAT) revealed a trend towards browning, with significantly increased transcription of several marker genes (Cidea, Ebf2, Pgc1α, PPARγ, Sirt1, and Tbx1) and an increase in UCP1 protein levels, which, however, did not achieve significance. Given the lack of known side effects of Pt, this study strengthens the candidacy of this natural phenol as an anti-obesity nutraceutical.

Targeting Brain Disease in MPSII: Preclinical Evaluation of IDS-Loaded PLGA Nanoparticles.

Mucopolysaccharidosis type II (MPSII) is a lysosomal storage disorder due to the deficit of the enzyme iduronate 2-sulfatase (IDS), which leads to the accumulation of glycosaminoglycans in most organ-systems, including the brain, and resulting in neurological involvement in about two-thirds of the patients. The main treatment is represented by a weekly infusion of the functional enzyme, which cannot cross the blood-brain barrier and reach the central nervous system. In this study, a tailored nanomedicine approach based on brain-targeted polymeric nanoparticles (g7-NPs), loaded with the therapeutic enzyme, was exploited. Fibroblasts from MPSII patients were treated for 7 days with NPs loaded with the IDS enzyme; an induced IDS activity like the one detected in healthy cells was measured, together with a reduction of GAG content to non-pathological levels. An in vivo short-term study in MPSII mice was performed by weekly administration of g7-NPs-IDS. Biochemical, histological, and immunohistochemical evaluations of liver and brain were performed. The 6-weeks treatment produced a significant reduction of GAG deposits in liver and brain tissues, as well as a reduction of some neurological and inflammatory markers (i.e., LAMP2, CD68, GFAP), highlighting a general improvement of the brain pathology. The g7-NPs-IDS approach allowed a brain-targeted enzyme replacement therapy. Based on these positive results, the future aim will be to optimize NP formulation further to gain a higher efficacy of the proposed approach.

Glucocerebrosidase deficiency in zebrafish affects primary bone ossification through increased oxidative stress and reduced Wnt/ß-catenin signaling.

Loss of lysosomal glucocerebrosidase (GBA1) function is responsible for several organ defects, including skeletal abnormalities in type 1 Gaucher disease (GD). Enhanced bone resorption by infiltrating macrophages has been proposed to lead to major bone defects. However, while more recent evidences support the hypothesis that osteoblastic bone formation is impaired, a clear pathogenetic mechanism has not been depicted yet. Here, by combining different molecular approaches, we show that Gba1 loss of function in zebrafish is associated with defective canonical Wnt signaling, impaired osteoblast differentiation and reduced bone mineralization. We also provide evidence that increased reactive oxygen species production precedes the Wnt signaling impairment, which can be reversed upon human GBA1 overexpression. Type 1 GD patient fibroblasts similarly exhibit reduced Wnt signaling activity, as a consequence of increased ß-catenin degradation. Our results support a novel model in which a primary defect in canonical Wnt signaling antecedes bone defects in type 1 GD.

Brain RNA-Seq Profiling of the Mucopolysaccharidosis Type II Mouse Model.

Lysosomal storage disorders (LSDs) are a group of about 50 genetic metabolic disorders, mainly affecting children, sharing the inability to degrade specific endolysosomal substrates. This results in failure of cellular functions in many organs, including brain that in most patients may go through progressive neurodegeneration. In this study, we analyzed the brain of the mouse model for Hunter syndrome, a LSD mostly presenting with neurological involvement. Whole transcriptome analysis of the cerebral cortex and midbrain/diencephalon/hippocampus areas was performed through RNA-seq. Genes known to be involved in several neurological functions showed a significant differential expression in the animal model for the disease compared to wild type. Among the pathways altered in both areas, axon guidance, calcium homeostasis, synapse and neuroactive ligand-receptor interaction, circadian rhythm, neuroinflammation and Wnt signaling were the most significant. Application of RNA sequencing to dissect pathogenic alterations of complex syndromes allows to photograph perturbations, both determining and determined by these disorders, which could simultaneously occur in several metabolic and biochemical pathways. Results also emphasize the common, altered pathways between neurodegenerative disorders affecting elderly and those associated with pediatric diseases of genetic origin, perhaps pointing out a general common course for neurodegeneration, independent from the primary triggering cause.

Glycosaminoglycan signatures in body fluids of mucopolysaccharidosis type II mouse model under long-term enzyme replacement therapy.

Mucopolysaccharidosis type II (MPS II) is a neurometabolic disorder, due to the deficit of the lysosomal hydrolase iduronate 2-sulfatase (IDS). This leads to a severe clinical condition caused by a multi-organ accumulation of the glycosaminoglycans (GAGs/GAG) heparan- and dermatan-sulfate, whose elevated levels can be detected in body fluids. Since 2006, enzyme replacement therapy (ERT) has been clinically applied, showing efficacy in some peripheral districts. In addition to clinical monitoring, GAG dosage has been commonly used to evaluate ERT efficacy. However, a strict long-term monitoring of GAG content and composition in body fluids has been rarely performed. Here, we report the characterization of plasma and urine GAGs in Ids knock-out (Ids-ko) compared to wild-type (WT) mice, and their changes along a 24-week follow-up, with and without ERT. The concentration of heparan-sulfate (HS), chondroitin-sulfate (CS), and dermatan-sulfate (DS), and of the non-sulfated hyaluronic acid (HA), together with their differentially sulfated species, was quantified by capillary electrophoresis with laser-induced fluorescence. In untreated Ids-ko mice, HS and CS + DS were noticeably increased at all time points, while during ERT follow-up, a substantial decrease was evidenced for HS and, to a minor extent, for CS + DS. Moreover, several structural parameters were altered in untreated ko mice and reduced after ERT, however without reaching physiological values. Among these, disaccharide B and HS 2s disaccharide showed to be the most interesting candidates as biomarkers for MPS II. GAG chemical signature here defined provides potential biomarkers useful for an early diagnosis of MPS II, a more accurate follow-up of ERT, and efficacy evaluations of newly proposed therapies. KEY MESSAGES : Plasmatic and urinary GAGs are useful markers for MPS II early diagnosis and prognosis. CE-LIF allows GAG structural analysis and the quantification of 17 different disaccharides. Most GAG species increase and many structural features are altered in MPS II mouse model. GAG alterations tend to restore to wild-type levels following ERT administration. CS+DS/HS ratio, % 2,4dis CS+DS, and % HS 2s are potential markers for MPS II pathology and ERT efficacy.

In vitro and in vivo anticancer activity of tridentate thiosemicarbazone copper complexes: Unravelling an unexplored pharmacological target.

Certain metal complexes can have a great antitumor activity, as the use of cisplatin in therapy has been demonstrating for the past fifty years. Copper complexes, in particular, have attracted much attention as an example of anticancer compounds based on an endogenous metal. In this paper we present the synthesis and the activity of a series of copper(II) complexes with variously substituted salicylaldehyde thiosemicarbazone ligands. The in vitro activity of both ligands and copper complexes was assessed on a panel of cell lines (HCT-15, LoVo and LoVo oxaliplatin resistant colon carcinoma, A375 melanoma, BxPC3 and PSN1 pancreatic adenocarcinoma, BCPAP thyroid carcinoma, 2008 ovarian carcinoma, HEK293 non-transformed embryonic kidney), highlighting remarkable activity of the metal complexes, in some cases in the low nanomolar range. The copper(II) complexes were also screened, with good results, against 3D spheroids of colon (HCT-15) and pancreatic (PSN1) cancer cells. Detailed investigations on the mechanism of action of the copper(II) complexes are also reported: they are able to potently inhibit Protein Disulfide Isomerase, a copper-binding protein, that is recently emerging as a new therapeutic target for cancer treatment. Good preliminary results obtained in C57BL mice indicate that this series of metal-based compounds could be a very promising weapon in the fight against cancer.

Cholesterol-Lowering Action of a Novel Nutraceutical Combination in Uremic Rats: Insights into the Molecular Mechanism in a Hepatoma Cell Line.

Appropriate nutraceutical combinations may represent a valid approach to prevent vascular calcification associated with chronic kidney disease (CKD). In the present study, we tested the effect of a new nutraceutical combination named RenaTris®, containing MK-7, magnesium carbonate, and Sucrosomial® Iron, on vascular calcification in uremic rats. Rats were randomly divided into three groups, i.e. control (high-phosphate diet), uremic (high-phosphate diet containing 0.5% adenine), and supplemented uremic diet (0.5% adenine, MK-7, magnesium carbonate, and Sucrosomial® Iron). After six weeks, sera and vascular calcification were examined. The uremic diet increased creatinine and phosphate levels and induced extensive vascular calcification. The uremic condition also induced a mild hypercholesterolemic condition (+52% of total cholesterol; p < 0.05). The supplemented uremic diet did not reduce creatinine, phosphate levels, or vascular calcification, however, we observed a significant hypocholesterolemic effect (-18.9% in supplemental uremic vs. uremic diet; p < 0.05). Similar to simvastatin, incubation of cultured human hepatoma cells (Huh7) with MK-7 significantly reduced cholesterol biosynthesis (-38%) and induced 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase and low-density lipoprotein receptor (LDLR) at both mRNA and protein levels. The effect of MK-7 on LDLR was counteracted by the co-incubation with squalene. Unlike simvastatin, MK-7 reduced PCSK9 in Huh7. These results indicated that the new nutraceutical combination significantly impacts cholesterol metabolism and its supplementation may help to control mild hypercholesterolemic conditions in CKD patients.

Cisplatin liposome and 6-amino nicotinamide combination to overcome drug resistance in ovarian cancer cells.

Ovarian cancer is an aggressive and lethal cancer usually treated by cytoreductive surgery followed by chemotherapy. Unfortunately, after an initial response, many patients relapse owing mainly to the development of resistance against the standard chemotherapy regime, carboplatin/paclitaxel, which is also affected by heavy side effects. In view to addressing such issues here, an association of liposomal cisplatin with 6-amino nicotinamide is investigated. It is known that resistant cells increase their demand for glucose, which is partially redirected toward the pentose phosphate pathway (PPP). Interestingly, we have found that also a cisplatin-resistant subclone of the ovarian cancer cells IGROV1 switch their metabolism toward the glycolytic pathway and rely on PPP to elude cisplatin cytotoxicity. The drug 6-amino nicotinamide, an inhibitor of the enzyme glucose-6-phosphate dehydrogenase (the rate-limiting step of the PPP) can restore the sensitivity of resistant cells to cisplatin. Then, to reduce the toxicity of cisplatin and prolong its action, a lyophilized stealth liposomal formulation of cisplatin was developed. The combination treatment of liposomal cisplatin and 6-amino nicotinamide showed promising cytotoxic activities in drug-resistant cells and a prolonged pharmacokinetics in rats, thus opening the way for a new therapeutic option against ovarian cancer.

Targeted Polymeric Nanoparticles for Brain Delivery of High Molecular Weight Molecules in Lysosomal Storage Disorders.

Lysosomal Storage Disorders (LSDs) are a group of metabolic syndromes, each one due to the deficit of one lysosomal enzyme. Many LSDs affect most of the organ systems and overall about 75% of the patients present neurological impairment. Enzyme Replacement Therapy, although determining some systemic clinical improvements, is ineffective on the CNS disease, due to enzymes' inability to cross the blood-brain barrier (BBB). With the aim to deliver the therapeutic enzymes across the BBB, we here assayed biodegradable and biocompatible PLGA-nanoparticles (NPs) in two murine models for LSDs, Mucopolysaccharidosis type I and II (MPS I and MPS II). PLGA-NPs were modified with a 7-aminoacid glycopeptide (g7), yet demonstrated to be able to deliver low molecular weight (MW) molecules across the BBB in rodents. We specifically investigated, for the first time, the g7-NPs ability to transfer a model drug (FITC-albumin) with a high MW, comparable to the enzymes to be delivered for LSDs brain therapy. In vivo experiments, conducted on wild-type mice and knockout mouse models for MPS I and II, also included a whole series of control injections to obtain a broad preliminary view of the procedure efficiency. Results clearly showed efficient BBB crossing of albumin in all injected mice, underlying the ability of NPs to deliver high MW molecules to the brain. These results encourage successful experiments with enzyme-loaded g7-NPs to deliver sufficient amounts of the drug to the brain district on LSDs, where exerting a corrective effect on the pathological phenotype.

Circadian transcriptome analysis in human fibroblasts from Hunter syndrome and impact of iduronate-2-sulfatase treatment.

BACKGROUND: Hunter syndrome (HS) is a lysosomal storage disease caused by iduronate-2-sulfatase (IDS) deficiency and loss of ability to break down and recycle the glycosaminoglycans, heparan and dermatan sulfate, leading to impairment of cellular processes and cell death. Cell activities and functioning of intracellular organelles are controlled by the clock genes (CGs), driving the rhythmic expression of clock controlled genes (CCGs). We aimed to evaluate the expression of CGs and downstream CCGs in HS, before and after enzyme replacement treatment with IDS. METHODS: The expression levels of CGs and CCGs were evaluated by a whole transcriptome analysis through Next Generation Sequencing in normal primary human fibroblasts and fibroblasts of patients affected by HS before and 24 h/144 h after IDS treatment. The time related expression of CGs after synchronization by serum shock was also evaluated by qRT-PCR before and after 24 hours of IDS treatment. RESULTS: In HS fibroblasts we found altered expression of several CGs and CCGs, with dynamic changes 24 h and 144 h after IDS treatment. A semantic hypergraph-based analysis highlighted five gene clusters significantly associated to important biological processes or pathways, and five genes, AHR, HIF1A, CRY1, ITGA5 and EIF2B3, proven to be central players in these pathways. After synchronization by serum shock and 24 h treatment with IDS the expression of ARNTL2 at 10 h (p = 0.036), PER1 at 4 h (p = 0.019), PER2 at 10 h (p = 0.041) and 16 h (p = 0.043) changed in HS fibroblasts. CONCLUSION: CG and CCG expression is altered in HS fibroblasts and IDS treatment determines dynamic modifications, suggesting a direct involvement of the CG machinery in the physiopathology of cellular derangements that characterize HS.