Structural effects of methylglyoxal glycation, a study on the model protein MNEI.
Publication Date: 16/07/2018, on Molecular and cellular biochemistry
by Leone S, Fonderico J, Melchiorre C, Carpentieri A, Picone D
The reaction of free amino groups in proteins with reactive carbonyl species, known as glycation, leads to the formation of mixtures of products, collectively referred to as advanced glycation endproducts (AGEs). These compounds have been implicated in several important diseases, but their role in pathogenesis and clinical symptoms' development is still debated. Particularly, AGEs are often associated to the formation of amyloid deposits in conformational diseases, such as Alzheimer's and Parkinson's disease, and it has been suggested that they might influence the mechanisms and kinetics of protein aggregation. We here present the characterization of the products of glycation of the model protein MNEI with methylglyoxal and their effect on the protein structure. We demonstrate that, despite being an uncontrolled process, glycation occurs only at specific residues of the protein. Moreover, while not affecting the protein fold, it alters its shape and hydrodynamic properties and increases its tendency to fibrillar aggregation. Our study opens the way to in deep structural investigations to shed light on the complex link between protein post-translational modifications, structure, and stability.
Migraine as possible red flag of PFO presence in suspected demyelinating disease.
Publication Date: 15/07/2018, on Journal of the neurological sciences
by Signoriello E, Cirillo M, Puoti G, Signoriello G, Negro A, Koci E, Melone MAB, Rapacciuolo A, Maresca G, Lus G
To investigate a possible association between isolated white matter lesions suggestive of demyelinating disease in magnetic resonance imaging (MRI) and patent foramen ovale (PFO) evidence in migraine patients, with or without aura.
Hybrid complexes of high and low molecular weight hyaluronan delay in vitro replicative senescence of mesenchymal stromal cells: a pilot study for future therapeutic application.
Publication Date: 12/07/2018, on Aging
by Alessio N, Stellavato A, Squillaro T, Del Gaudio S, Di Bernardo G, Peluso G, De Rosa M, Schiraldi C, Galderisi U
Mesenchymal stem cells, a subpopulation of mesenchymal stromal cells (MSCs), are present in the stroma of several tissues. MSC cultivation for clinical treatments may greatly affect MSC properties. A primary handicap is replicative senescence that impairs MSC functions. Hyaluronan (HA) is present in the extracellular matrix that composes the stem cell niche environment and is under investigation as a key factor for stem cell growth. We evaluated the effect on MSC cultivation of HA hybrid cooperative complexes (HCC) that are obtained from high (H) and low (L) weight molecules (NAHYCO™). We compared this HCC with H-HA and L-HA. We investigated the effects of these HAs on proliferation, cell cycle, apoptosis, senescence, and differentiation following the addition of the polymer solutions in the culture media at concentrations that did not drastically modify the medium viscosity. Interestingly, 0,16% HCC significantly delayed the senescence compared with the controls. This occurred without alteration of the cell cycle, cytotoxicity, or apoptosis. HCCs also promoted adipogenic and chondrogenic differentiation. Our finding could suggest a potential functional role of HCC above the updated scientific reports of its effects and pave the way to optimization of MSC cultivation for therapeutic application.
Long Feeding High-Fat Diet Induces Hypothalamic Oxidative Stress and Inflammation, and Prolonged Hypothalamic AMPK Activation in Rat Animal Model.
Publication Date: 06/07/2018, on Frontiers in physiology
by Cavaliere G, Viggiano E, Trinchese G, De Filippo C, Messina A, Monda V, Valenzano A, Cincione RI, Zammit C, Cimmino F, Catapano A, Sessa F, Messina G, Monda M, Crispino M, Mollica MP
The hypothalamus is a key brain region involved in the control of feeding and energy expenditure. Hypothalamic inflammation and oxidative stress are landmarks of both obesity and aging processes, although the molecular mechanisms are still unknown. Therefore, with the aim to understand the neurobiological mechanisms of energy homeostasis during aging, we evaluate the effects of long feeding high-fat diet (HFD) in rats, at different age, on modulation of hypothalamic molecular pathway, oxidative stress, and inflammation. Male Wistar rats were divided into two groups: control group, receiving standard diet (CD), and treated group, receiving HFD. Both groups were treated with the appropriate diet for 1, 3, 6, 12, or 18 weeks. We investigated energy balance and body composition, as well as lipid profile, homeostatic model assessment index, and inflammatory state in serum. Furthermore, we also analyzed, at hypothalamic level, inflammation and oxidative stress, and adenosine monophosphate-dependent kinase (AMPK) and pAMPK expression levels. Our data showed that aging and HFD induce increased energy intake and energy efficiency and decreased energy expenditure associated, at hypothalamic level, with inflammation and oxidative stress and activation of AMPK. Our results indicate that the age at which HFD feeding starts and the diet duration are critical in obesity development. The prolonged activation of hypothalamic AMPK may be related to the alterations in energy homeostasis.
Nrf2 Pathway in Age-Related Neurological Disorders: Insights into MicroRNAs.
Publication Date: 03/07/2018, on Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology
by Paladino S, Conte A, Caggiano R, Pierantoni GM, Faraonio R
A general hallmark of neurological diseases is the loss of redox homeostasis that triggers oxidative damages to biomolecules compromising neuronal function. Under physiological conditions the steady-state concentrations of reactive oxygen species (ROS) and reactive nitrogen species (RNS) are finely regulated for proper cellular functions. Reduced surveillance of endogenous antioxidant defenses and/or increased ROS/RNS production leads to oxidative stress with consequent alteration of physiological processes. Neuronal cells are particularly susceptible to ROS/RNS due to their biochemical composition. Overwhelming evidences indicate that nuclear factor (erythroid-derived 2)-like 2 (Nrf2)-linked pathways are involved in protective mechanisms against oxidative stress by regulating antioxidant and phase II detoxifying genes. As such, Nrf2 deregulation has been linked to both aging and pathogenesis of many human chronic diseases, including neurodegenerative ones such as Parkinson's disease, Alzheimer's disease and amyotrophic lateral sclerosis. Nrf2 activity is tightly regulated by a fine balance between positive and negative modulators. A better understanding of the regulatory mechanisms underlying Nrf2 activity could help to develop novel therapeutic interventions to prevent, slow down or possibly reverse various pathological states. To this end, microRNAs (miRs) are attractive candidates because they are linked to intracellular redox status being regulated and, post-transcriptionally, regulating key components of ROS/RNS pathways, including Nrf2.
Dilated Virchow-Robin space and Parkinson's disease: A case report of combined MRI and diffusion tensor imaging.
Publication Date: 30/06/2018, on Radiology case reports
by Conforti R, Sardaro A, Negro A, Caiazzo G, Paccone A, De Micco R, Cirillo S, Tessitore A
In this manuscript we report the case of a 69-year-old female patient, who suffers from Parkinson's disease (PD) with a dilated Virchow-Robin space (dVRS) on the left anterior perforated substance. During a magnetic resonance imaging examination, the presence of a dVRS was discovered on the left anterior perforated substance. Subsequently, the patient has been subjected to further investigation of magnetic resonance imaging and diffusion tensor imaging (DTI). The DTI data of our PD patient showed increased peak frequency of left fractional anisotropy and decreases in the distribution of Mean Diffusivity(MD) with changes in the fiber density compared to the normal contralateral tract. We hypothesize that the DTI changes are due to dVRS. In the text a review of the recent literature on the presence of dVRSs, located in mono and bilateral seat, in patients with PD is reported, explaining its possible implications on disease progression, cognitive decline, and worsening of symptoms.
Novel VCP mutations expand the mutational spectrum of frontotemporal dementia.
Publication Date: 30/06/2018, on Neurobiology of aging
by Saracino D, Clot F, Camuzat A, Anquetil V, Hannequin D, Guyant-Maréchal L, Didic M, Guillot-Noël L, Rinaldi D, Latouche M, Forlani S, Ghassab Y, Coppola C, Di Iorio G, David I, , Le Guern E, Brice A, Le Ber I
Valosin-containing protein (VCP) mutations are rare causes of autosomal dominant frontotemporal dementias associated with Paget's disease of bone, inclusion body myopathy, and amyotrophic lateral sclerosis. We analyzed the VCP gene in a cohort of 199 patients with frontotemporal dementia and identified 7 heterozygous mutations in unrelated families, including 3 novel mutations segregating with dementia. This expands the VCP mutation spectrum and suggests that although VCP mutations are rare (3.5% in this study), the gene should be analyzed even in absence of the full syndromic complex. Reporting genetic variants with convincing arguments for pathogenicity is important considering the large amount of data generated by next-generation sequencing and the growing difficulties to interpret rare genetic variants identified in isolated cases.
Glycation affects fibril formation of Aβ peptides.
Publication Date: 29/06/2018, on The Journal of biological chemistry
by Emendato A, Milordini G, Zacco E, Sicorello A, Dal Piaz F, Guerrini R, Thorogate R, Picone D, Pastore A
Increasing evidence shows that Aβ peptides, which are associated with Alzheimer disease (AD), are heavily glycated in patients, suggesting a role of this irreversible non-enzymatic post-translational modification in pathology. Previous reports have shown that glycation increases the toxicity of the Aβ peptides although little is known about the mechanism. Here, we used the natural metabolic byproduct methylglyoxal as a glycating agent and exploited various spectroscopic methods and atomic force microscopy to study how glycation affects the structures of the Aβ40 and Aβ42 peptides, the aggregation pathway, and the morphologies of the resulting aggregates. We found that glycation significantly slows down but does not prevent β-conversion to mature fibres. We propose that the previously reported higher toxicity of the glycated Aβ peptides could be explained by a longer persistence in an oligomeric form, usually believed to be the toxic species.
Targeting Heparan Sulfate Proteoglycans as a Novel Therapeutic Strategy for Mucopolysaccharidoses.
Publication Date: 18/06/2018, on Molecular therapy. Methods & clinical development
by De Pasquale V, Sarogni P, Pistorio V, Cerulo G, Paladino S, Pavone LM
Mucopolysaccharidoses (MPSs) are inherited metabolic diseases caused by the deficiency of lysosomal enzymes needed to catabolize glycosaminoglycans (GAGs). Four therapeutic options are currently considered: enzyme replacement therapy, substrate reduction therapy, gene therapy, and hematopoietic stem cell transplantation. However, while some of them exhibit limited clinical efficacy and require high costs, others are still in development. Therefore, alternative treatments for MPSs need to be explored. Here we describe an innovative therapeutic approach based on the use of a recombinant protein that is able to bind the excess of extracellular accumulated heparan sulfate (HS). We demonstrate that this protein is able to reduce lysosomal defects in primary fibroblasts from MPS I and MPS IIIB patients. We also show that, by masking the excess of extracellular accumulated HS in MPS fibroblasts, fibroblast growth factor (FGF) signal transduction can be positively modulated. We, therefore, suggest the use of a competitive binding molecule for HS in MPSs as an alternative strategy to prevent the detrimental extracellular substrate storage.
Mesenchymal stromal cells from amniotic fluid are less prone to senescence compared to those obtained from bone marrow: An in vitro study.
Publication Date: 15/06/2018, on Journal of cellular physiology
by Alessio N, Pipino C, Mandatori D, Di Tomo P, Ferone A, Marchiso M, Melone MAB, Peluso G, Pandolfi A, Galderisi U
Mesenchymal stromal cells (MSCs) are considered to be an excellent source in regenerative medicine. They contain several cell subtypes, including multipotent stem cells. MSCs are of particular interest as they are currently being tested using cell and gene therapies for a number of human diseases. They represent a rare population in tissues; for this reason, they require, before being transplanted, an in vitro amplification. This process may induce replicative senescence, thus affecting differentiation and proliferative capacities. Increasing evidence suggests that MSCs from fetal tissues are significantly more plastic and grow faster than MSCs from bone marrow. Here, we compare amniotic fluid mesenchymal stromal cells (AF-MSCs) and bone marrow mesenchymal stromal cells (BM-MSCs) in terms of cell proliferation, surface markers, multidifferentiation potential, senescence, and DNA repair capacity. Our study shows that AF-MSCs are less prone to senescence with respect to BM-MSCs. Moreover, both cell models activate the same repair system after DNA damage, but AF-MSCs are able to return to the basal condition more efficiently with respect to BM-MSCs. Indeed, AF-MSCs are better able to cope with genotoxic stress that may occur either during in vitro cultivation or following transplantation in patients. Our findings suggest that AF-MSCs may represent a valid alternative to BM-MSCs in regenerative medicine, and, of great relevance, the investigation of the mechanisms involved in DNA repair capacity of both AF-MSCs and BM-MSCs may pave the way to their rational use in the medical field.
Smenamide A Analogues. Synthesis and Biological Activity on Multiple Myeloma Cells.
Publication Date: 13/06/2018, on Marine drugs
by Caso A, Laurenzana I, Lamorte D, Trino S, Esposito G, Piccialli V, Costantino V
Smenamides are an intriguing class of peptide/polyketide molecules of marine origin showing antiproliferative activity against lung cancer Calu-1 cells at nanomolar concentrations through a clear pro-apoptotic mechanism. To probe the role of the activity-determining structural features, the 16--analogue of smenamide A and eight simplified analogues in the 16- series were prepared using a flexible synthetic route. The synthetic analogues were tested on multiple myeloma (MM) cell lines showing that the configuration at C-16 slightly affects the activity, since the 16--derivative is still active at nanomolar concentrations. Interestingly, it was found that the truncated compound , mainly composed of the pyrrolinone terminus, was not active, while compound , essentially lacking the pyrrolinone moiety, was 1000-fold less active than the intact substance and was the most active among all the synthesized compounds.
Clinical activity after fingolimod cessation: disease reactivation or rebound?
Publication Date: 31/05/2018, on European journal of neurology
by Frau J, Sormani MP, Signori A, Realmuto S, Baroncini D, Annovazzi P, Signoriello E, Maniscalco G, La Gioia S, Cordioli C, Frigeni B, Rasia S, Fenu G, Grasso R, Sartori A, Lanzillo R, Stromillo ML, Rossi S, Forci B, Cocco E,
There is debate as to whether the apparent rebound after fingolimod discontinuation is related to the discontinuation itself, or if it is due to the natural course of highly active multiple sclerosis (MS). We aimed to survey the prevalence of severe reactivation and rebound after discontinuation of fingolimod in a cohort of Italian patients with MS.
Cognitive performance in multiple sclerosis: the contribution of intellectual enrichment and brain MRI measures.
Publication Date: 26/05/2018, on Journal of neurology
by Santangelo G, Bisecco A, Trojano L, Sacco R, Siciliano M, d'Ambrosio A, Della Corte M, Lavorgna L, Bonavita S, Tedeschi G, Gallo A
Cognitive reserve (CR) is a construct that originates from the observation of poor correspondence between brain damage and clinical symptoms. The aim of the study was to investigate the association between cognitive reserve (CR), brain reserve (BR) and cognitive functions and to evaluate whether CR might attenuate/moderate the negative impact of brain atrophy and lesion load on cognitive functions in multiple sclerosis (MS). To achieve these aims, ninety-eight relapsing-remitting MS patients underwent the brief repeatable battery of neuropsychological tests and Stroop test (ST). CR was assessed by vocabulary-based estimate of lifetime intellectual enrichment. All patients underwent a 3T MRI to assess T2-lesion load and atrophy measures, including normalized gray matter and white matter (nWMV) volumes. The BR was evaluated by maximal lifetime brain volume expressed by intracranial volume (ICV). Hierarchical regressions were used to investigate whether higher BR and/or CR is related to better cognitive performances after controlling for potentially confounding factors. The ICV was not associated with any cognitive tests. Intellectual enrichment was positively associated with performance on tests assessing memory, attention and information processing speed, verbal fluency and inhibitory control. Significant relationship between nWMV and ST was moderated by intellectual enrichment. In conclusion, the findings suggested that CR seems to mitigate cognitive dysfunction in MS patients and can reduce the negative impact of brain atrophy on inhibitory control, relevant for integrity of instrumental activities of daily living.
Do medical complications impact long-term outcomes in prolonged disorders of consciousness?
Publication Date: 25/05/2018, on Archives of physical medicine and rehabilitation
by Estraneo A, Loreto V, Masotta Psy O, Pascarella A, Trojano L
to investigate medical complications (MC) occuring within 6 months post-injury in brain-injured patients with prolonged disorders of consciousness (DoC) and to evaluate impact of MC on mortality and long-term clinical outcomes.
Autophagy-Associated Shrinkage of the Hepatopancreas in Fasting Male <i>Macrobrachium rosenbergii</i> Is Rescued by Neuropeptide F.
Publication Date: 24/05/2018, on Frontiers in physiology
by Thongrod S, Wanichanon C, Kankuan W, Siangcham T, Phadngam S, Morani F, Isidoro C, Sobhon P
Invertebrate neuropeptide F-I (NPF-I), much alike its mammalian homolog neuropeptide Y, influences several physiological processes, including circadian rhythms, cortical excitability, stress response, and food intake behavior. Given the role of autophagy in the metabolic stress response, we investigated the effect of NPF-1 on autophagy during fasting and feeding conditions in the hepatopancreas and muscle tissues of the male giant freshwater prawn . Starvation up-regulated the expression of the autophagy marker LC3 in both tissues. Yet, based on the relative levels of the autophagosome-associated LC3-II isoform and of its precursor LC3-I, the hepatopancreas was more responsive than the muscle to starvation-induced autophagy. Injection of NPF-I inhibited the autophagosome formation in the hepatopancreas of fasting prawns. Relative to the body weight, the muscle weight was not affected, while that of the hepatopancreas decreased upon starvation and NPF-1 treatment could largely prevent such weight loss. Thus, the hepatopancreas is the reserve organ for the nutrient homeostasis during starvation and NPF-I plays a crucial role in the balancing of energy expenditure and energy intake during starvation by modulating autophagy.