Early intrathecal infusion of everolimus restores cognitive function and mood in a murine model of Alzheimer's disease

The discovery that mammalian target of rapamycin (mTOR) inhibition increases lifespan in mice and restores/delays many aging phenotypes has led to the identification of a novel potential therapeutic target for the treatment of Alzheimer's disease (AD). Among mTOR inhibitors, everolimus, which has been developed to improve the pharmacokinetic characteristics of rapamycin, has been extensively profiled in preclinical and clinical studies as anticancer and immunosuppressive agent, but no information is available about its potential effects on neurodegenerative disorders. Using a reliable mouse model of AD (3 × Tg-AD mice), we explored whether short-term treatment with everolimus injected directly into the brain by osmotic pumps was able to modify AD-like pathology with low impact on peripheral organs. We first established in non-transgenic mice the stability of everolimus at 37 °C in comparison with rapamycin and, then, evaluated its pharmacokinetics and pharmacodynamics profiles through either a single peripheral (i.p.) or central (i.c.v.) route of administration. Finally, 6-month-old (symptomatic phase) 3 × Tg-AD mice were treated with continuous infusion of either vehicle or everolimus (0.167 μg/μl/day, i.c.v.) using the osmotic pumps. Four weeks after the beginning of infusion, we tested our hypothesis following an integrated approach, including behavioral (tests for cognitive and depressive-like alterations), biochemical and immunohistochemical analyses. Everolimus (i) showed higher stability than rapamycin at 37 °C, (ii) poorly crossed the blood-brain barrier after i.p. injection, (iii) was slowly metabolized in the brain due to a longer t 1/2 in the brain compared to blood, and (iv) was more effective in the CNS when administered centrally compared to a peripheral route. Moreover, the everolimus-induced mTOR inhibition reduced human APP/Aβ and human tau levels and improved cognitive function and depressive-like phenotype in the 3 × Tg-AD mice. The intrathecal infusion of everolimus may be effective to treat early stages of AD-pathology through a short and cyclic administration regimen, with short-term outcomes and a low impact on peripheral organs

Second hematopoietic SCT in patients with thalassemia recurrence following rejection of the first graft

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\u3b2-Hexosaminidase over-expression affects Lysosomal glycohydrolases expression and glycosphingolipid metabolism in mammalian cells

Lysosomes are not only degrading organelles but also involved in other critical cellular processes. In addition, active lysosomal glycohydrolases have been detected in an extra-lysosomal compartment: the presence of glycohydrolases on the plasma membrane (PM) has been widely demonstrated, and a possible role on the modification of the cell surface glycosphingolipids (GSL) participating in the modulation of cell functions such as cell-to-cell interactions and signal transduction pathways has been proposed. On this basis, the coordinated expression of lysosomal glycohydrolases and their translocation to the PM appear to be crucial for many cellular events. In this paper, we report evidence for the existence of a coordinated mechanism regulating the expression/activity of both lysosomal and PM-associated glycohydrolases. We show that the over-expression of the acidic glycohydrolase beta-hexosaminidase alpha-subunit in mouse NIH/3T3 fibroblasts induces the increased expression of the Hex beta-subunit necessary to form the active isoenzyme dimers as well as of other glycohydrolases participating in the GSL catabolism, such as beta-galactosidase and beta-glucocerebrosidase. More interestingly, this regulatory effect was also extended to the PM-associated hydrolases. In addition, transfected cells displayed a rearrangement of the GSL expression pattern that cannot be simply explained by the increased activity of a single enzyme. These observations clearly indicate that the expression level of metabolically related glycohydrolases is regulated in a coordinated manner and this regulation mechanism also involves the PM-associated isoforms

TFEB activation promotes the recruitment of lysosomal glycohydrolases \u3b2-hexosaminidase and \u3b2-galactosidase to the plasma membrane.

Lysosomes are membrane-enclosed organelles containing acid hydrolases. They mediate a variety of physiological processes, such as cellular clearance, lipid homeostasis, energy metabolism and pathogen defence. Lysosomes can secrete their content through a process called lysosome exocytosis in which lysosomes fuse with the plasma membrane realising their content into the extracellular milieu. Lysosomal exocytosis is not only responsible for the secretion of lysosomal enzymes, but it also has a crucial role in the plasma membrane repair. Recently, it has been demonstrated that lysosome response to the physiologic signals is regulated by the transcription factor EB (TFEB). In particular, lysosomal secretion is transcriptionally regulated by TFEB which induces both the docking and fusion of lysosomes with the plasma membrane. In this work we demonstrated that TFEB nuclear translocation is accompanied by an increase of mature glycohydrolases \u3b2-hexosaminidase and \u3b2-galactosidase on cell surface. This evidence contributes to elucidate an unknown TFEB biological function leading the lysosomal glycohydrolases on plasma membrane

Abnormal cortical lysosomal β-hexosaminidase and β-galactosidase activity at post-synaptic sites during Alzheimer's disease progression

A critical role of endosomal-lysosomal system alteration in neurodegeneration is supported by several studies. Dysfunction of the lysosomal compartment is a common feature also in Alzheimer's disease. Altered expression of lysosomal glycohydrolases has been demonstrated not only in the brain and peripheral tissues of Alzheimer's disease patients, but also in presymptomatic subjects before degenerative phenomenon becomes evident. Moreover, the presence of glycohydrolases associated to the plasma membrane have been widely demonstrated and their alteration in pathological conditions has been documented. In particular, lipid microdomains-associated glycohydrolases can be functional to the maintenance of the proper glycosphingolipids pattern, especially at cell surface level, where they are crucial for the function of cell types such as neurons. In this study we investigated the localization of \u3b2-hexosaminidase and \u3b2-galactosidase glycohydrolases, both involved in step by step degradation of the GM1 to GM3 gangliosides, in lipid microdomains from the cortex of both an early and advanced TgCRND8 mouse model of Alzheimer's disease. Throughout immunoprecipitation experiments of purified cortical lipid microdomains, we demonstrated for the first time that \u3b2-hexosaminidase and \u3b2-galactosidase are associated with post-synaptic vesicles and that their activities are increased at both the early and the advanced stage of Alzheimer's disease. The early increase of lipid microdomain-associated \u3b2-hexosaminidase and \u3b2-galactosidase activities could have relevant implications for the pathophysiology of the disease since their possible pharmacological manipulation could shed light on new reliable targets and biological markers of Alzheimer's disease

Allogeneic bone marrow transplantation from HBsAg+ donors: a multicenter study from the Gruppo Italiano Trapianto di Midollo Osseo (GITMO).

none9noneLocasciulli A;Alberti A;Bandini G;Polchi P;Arcese W;Alessandrino P;Bosi A;Testa M;Bacigalupo ALocasciulli, A; Alberti, Alfredo; Bandini, G; Polchi, P; Arcese, W; Alessandrino, P; Bosi, A; Testa, M; Bacigalupo, A