Maria E Pasini

University of Milan | UNIMI · Department of Life Sciences

Obesity is associated with various metabolic disorders, such as insulin resistance and adipose tissue inflammation (ATM), characterized by macrophage infiltration into adipose cells. This study presents a novel Drosophila model (OBL) to investigate the mechanisms underlying these obesity-related pathologies. We employed genetic manipulation to redu...

Obesity is a global health concern associated with various metabolic disorders including insulin resistance and adipose tissue inflammation characterized by adipose tissue macrophage (ATM) infiltration. In this study, we present a novel Drosophila model to investigate the mechanisms underlying ATM infiltration and its association with obesity-relat...

NOC1 is a nucleolar protein necessary in yeast for both transport and maturation of ribosomal subunits. Here, we show that Drosophila NOC1 is necessary for rRNAs maturation and for a correct animal development. Its ubiquitous downregulation results in a dramatic decrease in polysome level and of protein synthesis. NOC1 expression in multiple organs...

NOC1 is a nucleolar protein necessary in yeast for a correct transport of the large ribosomal subunit and ribosome biogenesis. Here we shown that ubiquitous downregulation of NOC1 in Drosophila results in defective polysome formation and decreases the rate of protein synthesis. Reduction of NOC1 is detrimental for animal growth and adequate express...

Glutamine Synthetase 1 (GS1) is a key enzyme that catalyzes the ATP-dependent synthesis of l-glutamine from l-glutamate and is also member of the Glutamate Glutamine Cycle, a complex physiological process between glia and neurons that controls glutamate homeostasis and is often found compromised in neurodegenerative diseases including Huntington’s...

Glutamine Synthetase1 (GS1) is an enzyme that catalyzes the ATP-dependent synthesis of L-glutamine from L-glutamate and ammonia as a key element of the glutamate glutamine cycle, a complex physiological process occurring between glia and neurons, necessary to control the homeostasis of glutamate. Using a Drosophila model for Huntington's disease, w...

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Background Pathological evidences showed that glutamate might play a role in HD. In the brain glutamate is maintained at physiological level by a non-autonomous cycle between glia and neurons called glutamate-glutamine cycle (GGC). Aims In order to understand the function of this cycle in neuronal survival and HD, we decide to use the flexibility...

Living organisms are important didactic tools for students, and we describe here for the first time the assessment of a scientific laboratory on Drosophila. The goal of this work is to attract more students to the science disciplines. We aimed to capture students' interest using educational experiences, and encourage the basic and integrated scienc...

The Na+/K+/Cl- cotransporter-1 (NKCC1) and the K+/Cl- cotransporter-2 (KCC2) set the transmembrane Cl- gradient in the brain, and are implicated in epileptogenesis. We studied the postnatal distribution of NKCC1 and KCC2 in wild-type (WT) mice, and in a mouse model of sleep-related epilepsy, carrying the mutant β2-V287L subunit of the nicotinic ace...

The alarming diffusion of multidrug resistant (MDR) bacterial strains requires investigations on non-antibiotic therapies. Amongst them, the use of bacteriophages (phages) as antimicrobial agents, namely phage therapy, is a promising treatment strategy with support by recent successful compassionate treatments in Europe and the U.S.A. In this work,...

Epidemiological and preclinical studies have demonstrated that bioactive foods like flavonoids, polyphenolic compounds derived from fruits and vegetables, exert a protective action against obesity, cardiovascular disorders, and Adipocyte Tissue Macrophage infiltration (ATM). All these pathologies are characterized by increase in reactive oxygen spe...

The sperm acrosome is a specialized vacuole, a member of the family of cell-specific lysosome-related organelles. Its exocytosis, the acrosome reaction, is a crucial event during fertilization. The released acrosomal contents promote sperm penetration through the investments of the oocyte, whereas the membranous components of the acrosome are invol...

Fertilization is a complex and multiphasic process, consisting of several steps, where egg-coating envelope's glycoproteins and sperm surface receptors play a critical role. Sperm-associated β-N-acetylglucosaminidases, also known as hexosaminidases, have been identified in a variety of organisms. Previously, two isoforms of hexosaminidases, named h...

Classification of morphological features in biological samples is usually performed by a trained eye but the increasing amount of available digital images calls for semi-automatic classification techniques. Here we explore this possibility in the context of acrosome morphological analysis during spermiogenesis. Our method combines feature extractio...

Lipids are an important energy supply in our cells and can be stored or used to produce macromolecules during lipogenesis when cells experience nutrient starvation. Our proteomic analysis reveals that the Drosophila homologue of human Stearoyl-CoA desaturase-1 (Desat1) is an indirect target of Myc in fat cells. Stearoyl-CoA desaturases are key enzy...

Living organisms can be used as important didactic tools for students, and we report here for the first time the evaluation of a scientific laboratory on Drosophila. The aim of this work is to attract more students towards science disciplines and a real appreciation for animal kingdom. We aimed to capture students' interest, develop important educa...

Background Neuronal death is often caused by an excess of glutamate that is maintained at physiological level by a non-autonomous cycle between glia and neurons called the glutamate-glutamine cycle. Aims It is possible to manipulate the activity of the enzymes that regulate the glutamate-glutamine cycle to ameliorate neuronal death? To answer this...

Understanding the role of microenvironment in cancer growth and metastasis is a key issue for cancer research. Here, we study the effect of osmotic pressure on the functional properties of primary and metastatic melanoma cell lines. In particular, we experimentally quantify individual cell motility and transmigration capability. We then perform a c...

Modulation of mRNA translatability either by trans-acting factors (proteins or sRNAs) or by in cis-acting riboregulators is widespread in bacteria and controls relevant phenotypic traits. Unfortunately, global identification of post-transcriptionally regulated genes is complicated by poor structural and functional conservation of regulatory element...

We studied the effect of hypocretin 1 (orexin A) in the frontal area 2 (Fr2) of the murine neocortex, implicated in the motivation-dependent goal-directed tasks. In layer V, hypocretin stimulated the spontaneous excitatory postsynaptic currents (EPSCs) on fast-spiking (FS) interneurons. The effect was accompanied by increased frequency of miniature...

In the adult central nervous system GABA mediates fast inhibitory transmission, whereas during development it is an excitatory transmitter and a trophic factor involved in controlling morphogenesis (Ben-Ari, 2002). This funcional shift occurs as a result of a progressively increasing expression of the KCC2 cotransporter, the major chloride extruder...

We studied how nicotinic acetylcholine receptors (nAChRs) regulate glutamate release in the secondary motor area (Fr2) of the dorsomedial murine prefrontal cortex, in the presence of steady agonist levels. Fr2 mediates response to behavioral situations that require immediate attention and is a candidate for generating seizures in the frontal epilep...

Usp8 is a deubiquitinating enzyme that works as regulator of endosomal trafficking and is involved in cell proliferation. "In vivo" USP8 is predominantly expressed in the central nervous system and testis, two organs with highly polarized cells. Considering that neuronal cell functionality is strictly dependent on vesicular traffic and ubiquitin-me...

Model organisms are frequently used in science teaching as they provide good exemplars for students that want to understand basic biological phenomena. The common sea urchin Paracentrotus lividus is a familiar animal that students can frequently observe in nature and represents a good didactic model for teaching various biological concepts in schoo...

A cDNA encoding an α-l-fucosidase from Drosophila melanogaster was obtained from the recombinant plasmid named pGEM-DmFuca and inserted into the pBacHTeGFPT vector to construct the recombinant donor plasmid which was transposed to the target AcBacmid in Escherichia coli (DH10) by Tn7 transposition function. The AcBacmid-GFP-DmFuca plasmid was used...

The Mediterranean fruit fly Ceratitis capitata (Diptera: Tephritidae) is one of the most destructive agricultural pests, a polyphagus insect of relevant economic importance and is widespread in many regions around the world. It is the best-studied fruit fly pest at genetic and molecular level and much has been learned on its ecology and behaviour....

The acrosome is a unique organelle that plays an important role at fertilization and during sperm morphogenesis and that is absent in globozoospermia, an inherited infertility syndrome in humans. At the light of recent experimental evidence, the acrosome is considered a lysosome-related organelle to whose biogenesis both the endocytic and biosynthe...

Model organisms play an important role in conveying biological concepts. They are more amenable to asking certain questions due to their simplicity of structure and features. The fruit fly Drosophila melanogaster has been the most popular eukaryotic organism used in classrooms, with a short life cycle of two weeks, making it possible to study numer...

Fruit flies in the family Tephritidae are rated among the world's most destructive agricultural pests. The Mediterranean fruit fly Ceratitis capitata is emerging as a model organism to study the fertilization in Insects. Three integral proteins with glycosidase activity are present in the plasma membrane of spermatozoa. The glycosidases have been p...

Drosophila obscura group species produce two distinct sizes of nucleated sperm that differ only in head and tail lenghts. Between both sperm there is no differences in location of the acrosome and flagellum during spermiogenesis where each sperm type develops in its own bundle. Fertile sperm accumulate in the seminal vesicles. Fertilization is ex-...

We have studied the presence of four sperm glycosidases, alpha-mannosidase, alpha-L- fucosidase and two beta-hexosaminidase isoforms, in 11 species of the genus Drosophila spanning approximately an evolutionary 60 MY period, and in Scaptodrosophila lebanonensis, belonging to the ancestor genus Scaptodrosophila. These enzymes had been previously ide...

The plasma membrane of Drosophila (Sophophora) melanogaster spermatozoa contains an alpha-l-fucosidase that might be involved in fertilization by interacting with alpha-l-fucose residues on the micropyle of the eggshell. D. (S.) melanogaster has a single gene called CG6128 or Fuca encoding for a putative alpha-l-fucosidase. Two transcripts have bee...

On Jun 29, 2007 this sequence version replaced gi:146217445.

Sperm surface β-N-acetylhexosaminidases are among the molecules mediating early gamete interactions in invertebrates and vertebrates, including man. The plasma membrane of Drosophila spermatozoa contains two β-N-acetylhexosaminidases, DmHEXA and DmHEXB, which are required for egg fertilization. Here, we demonstrate that three putative Drosophila me...

Previous studies from our laboratory have demonstrated the presence of two integral proteins with glycosidase activity in the plasma membrane of Drosophila melanogaster spermatozoa and we have suggested that these enzymes might have a role in sperm-egg binding. In this study the glycosidases have been purified and characterized. We have evidenced t...

The plasma membrane of the spermatozoa of Drosophila melanogaster contains two integral proteins with glycosidase activity, beta-N-acetylglucosaminidase and alpha-D-mannosidase. Biochemical analysis and ultrastructural cytochemistry of spermatozoa of the autosomal male sterile mutant casanova reveal that at least one of these enzymes, beta-N-acetyl...

The plasma membrane of the spermatozoa of Drosophila melanogaster contains two integral proteins with glycosidase activity, β-N-acetylglucosaminidase and α-D-mannosidase. Biochemical analysis and ultrastructural cytochemistry of spermatozoa of the autosomal male sterile mutant casanova reveal that at least one of these enzymes, β-N-acetylglucosamin...

Previous studies have identified beta-N-acetylglucosaminidase (GlcNAc'ase) and (alpha-mannosidase activities on the Drosophila melanogaster sperm surface which may have a role in fertilization. The aim of this study was to investigate their linkage to the sperm plasma membrane. We verified that glycosidases are not peripherally adsorbed to the cell...

Previous studies have identified β-N-acetylglucosaminidase (GlcNAc'ase) and α-mannosidase activities on the Drosophila melanogaster sperm surface which may have a role in fertilization. The aim of this study was to investigate their linkage to the sperm plasma membrane. We verified that glycosidases are not peripherally adsorbed to the cell surface...

We investigated the presence of enzymes on the surface of Drosophila melanogaster spermatozoa that might bind the carbohydrate residues of the egg shell. Spectrophotometric and fluorimetric studies were used on whole spermatozoa to assay galactosyltransferase and glycosidase activities. No galactosyltransferase is present on the sperm surface, wher...

In Drosophila subobscura the male produces two classes of motile spermatozoa that differ in total length and nucleus length. The significance of this within-ejaculate polymegaly is obscure. We have carried out an ultrastructural and cytochemical analysis of both sperm morphs to understand their possible role at fertilization. Computer-aided analysi...

The important roles played by glycoconjugates in the recognition of gametes and in fertilization are well documented. In the present study, the nature and distribution of carbohydrate residues of the plasma membrane of spermatozoa of Drosophila melanogaster were characterized by use of FITC-conjugated lectins as probes. The plasma membrane bound ag...

This study was conducted to evaluate the structural/ultrastructural characteristics of human testicular biopsies using immunocytochemical techniques on human testicular biopsies to establish: a) the area of the peritubular tissue in normal and altered seminiferous tubules, b) to characterize the nature of the extracellular components of the tubular...

A morphological analysis was carried out on testicular biopsies of men with obstructive azoospermia as consequence of vas deferens malformations as compared with biopsies from fertile men. For each case the biopsies were processed with two different techniques: routine histological procedure, and semithin sections of specimens processed for electro...

Testicular biopsies of fertile men and of azoospermic patients for vas deferens agenesis were processed with two different techniques, i.e. routine histological procedure and semithin sections of electron microscopy preparations. Tubular morphology, testicular biopsy score count and tubular diameter were analyzed in comparison. The two techniques g...