Marcelina Malinowska

Genistein Improves Neuropathology and Corrects Behaviour in a Mouse Model of Neurodegenerative Metabolic Disease

Background Neurodegenerative metabolic disorders such as mucopolysaccharidosis IIIB (MPSIIIB or Sanfilippo disease) accumulate undegraded substrates in the brain and are often unresponsive to enzyme replacement treatments due to the impermeability of the blood brain barrier to enzyme. MPSIIIB is characterised by behavioural difficulties, cognitive and later motor decline, with death in the second decade of life. Most of these neurodegenerative lysosomal storage diseases lack effective treatments. We recently described significant reductions of accumulated heparan sulphate substrate in liver of a mouse model of MPSIIIB using the tyrosine kinase inhibitor genistein. Methodology/Principal Findings We report here that high doses of genistein aglycone, given continuously over a 9 month period to MPSIIIB mice, significantly reduce lysosomal storage, heparan sulphate substrate and neuroinflammation in the cerebral cortex and hippocampus, resulting in correction of the behavioural defects observed. Improvements in synaptic vesicle protein expression and secondary storage in the cerebral cortex were also observed. Conclusions/Significance Genistein may prove useful as a substrate reduction agent to delay clinical onset of MPSIIIB and, due to its multimodal action, may provide a treatment adjunct for several other neurodegenerative metabolic diseases.

Modulation of expression of genes involved in glycosaminoglycan metabolism and lysosome biogenesis by flavonoids

Flavonoids were found previously to modulate efficiency of synthesis of glycosaminoglycans (GAGs), compounds which are accumulated in cells of patients suffering from mucopolysaccharidoses (MPSs). The aim of this work was to determine effects of different flavonoids (genistein, kaempferol, daidzein) used alone or in combinations, on expression of genes coding for proteins involved in GAG metabolism. Analyses with DNA microarray, followed by real-time qRT-PCR revealed that genistein, kaempferol and combination of these two compounds induced dose- and time-dependent remarkable alterations in transcript profiles of GAG metabolism genes in cultures of wild-type human dermal fibroblasts (HDFa). Interestingly, effects of the mixture of genistein and kaempferol were stronger than those revealed by any of these compounds used alone. Similarly, the most effective reduction in levels of GAG production, in both HDFa and MPS II cells, was observed in the presence of genistein, keampferol and combination of these compounds. Forty five genes were chosen for further verification not only in HDFa, but also in MPS II fibroblasts by using real-time qRT-PCR. Despite effects on GAG metabolism-related genes, we found that genistein, kaempferol and mixture of these compounds significantly stimulated expression of TFEB. Additionally, a decrease in MTOR transcript level was observed at these conditions.

Abnormalities in the hair morphology of patients with some but not all types of mucopolysaccharidoses

Mucopolysaccharidoses (MPS) are a group of inherited, progressive, metabolic diseases, caused by the deficiency of one of the enzymes involved in the degradation of glycosaminoglycans (GAGs). The disease is usually fatal, with the life span of most untreated MPS patients being between one and two decades. In this report, on the basis of scanning electron microscopy (SEM) studies, we demonstrate that, besides the many other symptoms of MPS, there are characteristic abnormalities in the hair morphology of patients suffering from some types of this disease (MPS I, MPS II, MPS IIIA, MPS IIIB), but not from other types (MPS IVA, MPS IVB, MPS VI), where the changes are minor, if any. Different GAGs accumulate in the tissues of patients suffering from the various MPS types, and analysis of the disease types in which severe hair abnormalities occur or not could suggest that the accumulation of heparan sulfate, rather than dermatan sulfate or keratan sufate, may be responsible for the major changes in hair morphology. Considerable abnormalities in hair morphology occur in patients suffering from MPS I, MPS II, MPS IIIA, and MPS IIIB, but not in patients suffering from MPS IVA, MPS IVB, and MPS VI; this feature might potentially be used as an additional test for the assessment of the efficacy of treatments for MPS patients (types I, II, IIIA, and IIIB).

Hyperactive behaviour in the mouse model of mucopolysaccharidosis IIIB in the open field and home cage environments

Mucopolysaccharidosis IIIB (MPS IIIB) is a lysosomal storage disorder characterized by severe behavioural disturbances and progressive loss of cognitive and motor function. There is no effective treatment, but behavioural testing is a valuable tool to assess neurodegeneration and the effect of novel therapies in mouse models of disease. Several groups have evaluated behaviour in this model, but the data are inconsistent, often conflicting with patient natural history. We hypothesize that this discrepancy could be due to differences in open field habituation and home cage behaviour. Eight‐month‐old wild‐type and MPS IIIB mice were tested in a 1‐h open field test, performed 1.5 h after lights on, and a 24‐h home cage behaviour test performed after 24 h of acclimatization. In the 1‐h test, MPS IIIB mice were hyperactive, with increased rapid exploratory behaviour and reduced immobility time. No differences in anxiety were seen. Over the course of the test, differences became more pronounced with maximal effects at 1 h. The 24‐hour home cage test was less reliable. There was evidence of increased hyperactivity in MPS IIIB mice, however, immobility was also increased, suggesting a level of inconsistency in this test. Performance of open field analysis within 1–2 h after lights on is probably critical to achieving maximal success as MPS IIIB mice have a peak in activity around this time. The open field test effectively identifies hyperactive behaviour in MPS IIIB mice and is a significant tool for evaluating effects of therapy on neurodegeneration.

Combined Therapies for Lysosomal Storage Diseases.

Lysosomal storage diseases (LSDs) is a group consisting of over 50 disorders caused mostly by dysfunctions of lysosomal proteins and resultant accumulation of particular compounds inside cells and extracellular volumes in affected organisms. Genetic diseases are among the most difficult targets for medical treatment. Nevertheless, understanding of molecular bases of LSDs made it possible to develop novel procedures of treatment, employing molecular medicine. Although various therapeutic approaches have been proposed, and some of them were introduced into clinical practice, none of them was found to be effective in correcting all symptoms in treated patients. Central nervous system and skeleton appear to be the most difficult targets to be improved. Therefore, a proposal appeared that perhaps no single therapeutic procedure may be fully effective in treatment of LSD patients, and only combination of two or more approaches could be a successful therapy. In this review, we present and discuss current stage of various combination therapies for LSDs, based on already available published data.

Glycosaminoglycans and mucopolysaccharidosis type III.

Mucopolysaccharidosis type III (MPS III), or Sanfilippo syndrome, is a lysosomal storage disease in which heparan sulfate is accumulated in lysosomes, as well as outside of cells, as the primary storage material. This disease is a complex of four conditions caused by dysfunctions of one of genes coding for lysosomal enzymes involved in degradation of heparan sulfate: SGSH (coding for heparan N-sulfatase) - causing MPS IIIA, NAGLU (coding for alpha-N-acetylglucosaminidase) - causing MPS IIIB, HGSNAT (coding for acetyl CoA alpha-glucosaminide acetyltransferase) - causing MPS IIIC), and GNS (coding for N-acetylglucosamine-6-sulfatase) - causing MPS IIID. The primary storage is responsible for some disease symptoms, but other arise as a result of secondary storage, including glycosphingolipids, and subsequent processes, like oxidative stress and neuroinflammation. Central nervous system is predominantly affected in all subtypes of MPS III. Heparan sulfate and its derivatives are the most commonly used biomarkers for diagnosis and prediction procedures. Currently, there is no therapy for Sanfilippo syndrome, however, clinical trials are ongoing for enzyme replacement therapy, gene therapy and substrate reduction therapy (particularly gene expression-targeted isoflavone therapy).

Corrigendum: Modulation of expression of genes involved in glycosaminoglycan metabolism and lysosome biogenesis by flavonoids.

Scientific Reports 5: Article number: 9378; published online: 23 March 2015; updated: 31 March 2016 This Article contains an error in Figure 3, where the numbers of genes are incorrectly indicated in the 24-hour and 48-hour sections. The correct Figure 3 appears below as Fig. 1.