77 research outputs found
Structural and biochemical insights of CypA and AIF interaction
The Cyclophilin A (CypA)/Apoptosis Inducing Factor (AIF) complex is implicated in the DNA degradation in response to various cellular stress conditions, such as oxidative stress, cerebral hypoxia-ischemia and traumatic brain injury. The pro-apoptotic form of AIF (AIF(Δ1-121)) mainly interacts with CypA through the amino acid region 370-394. The AIF(370-394) synthetic peptide inhibits complex formation in vitro by binding to CypA and exerts neuroprotection in a model of glutamate-mediated oxidative stress. Here, the binding site of AIF(Δ1-121) and AIF(370-394) on CypA has been mapped by NMR spectroscopy and biochemical studies, and a molecular model of the complex has been proposed. We show that AIF(370-394) interacts with CypA on the same surface recognized by AIF(Δ1-121) protein and that the region is very close to the CypA catalytic pocket. Such region partially overlaps with the binding site of cyclosporin A (CsA), the strongest catalytic inhibitor of CypA. Our data point toward distinct CypA structural determinants governing the inhibitor selectivity and the differential biological effects of AIF and CsA, and provide new structural insights for designing CypA/AIF selective inhibitors with therapeutic relevance in neurodegenerative diseases
Investigation of the Stereochemical-Dependent DNA and RNA Binding of Arginine-Based Nucleopeptides
Nucleopeptides represent an intriguing class of nucleic acid analogues, in which nucleobases
are placed in a peptide structure. The incorporation of D- and/or L-amino acids in nucleopeptide
molecules allows the investigation of the role of backbone stereochemistry in determining the
formation of DNA and RNA hybrids. Circular Dichroism (CD) spectroscopic studies indicated the
nucleopeptide as having fully l-backbone configuration-formed stable hybrid complexes with RNA
molecules. Molecular Dynamics (MD) simulations suggested a potential structure of the complex
resulting from the interaction between the l-nucleopeptide and RNA strand. From this study, both the
backbone (ionics and H-bonds) and nucleobases (pairing and pi-stacking) of the chiral nucleopeptide
appeared to be involved in the hybrid complex formation, highlighting the key role of the backbone
stereochemistry in the formation of the nucleopeptide/RNA complexes.This research was supported by Scientific Independence of Young Researchers (SIR) 2014 (RBSI142AMA)
and University of Campania Luigi Vanvitelli (Valere) to S.D.M
Genere Generi. Disuguaglianze e differenze
IL testo analizza il sistema dei generi attraverso una proposta di mappa del mainstreaming dei gener
Different levels of Cd45pos leukocytes in the semen of patients with low testicular volume.
The aim of this study was to evaluate the concentrations of CD45pos leukocytes in the semen samples of infertile patients with low testicular volume (TV) compared to subjects with normal TV. The testis was considered normal in size when it had a volume between 15 and 25 cm3, low–normal with a volume between 10 and 12 cm3 and hypotrophic when the volume was <10 cm3. The patients with low testicular volume (<10 cm3) showed significantly higher concentrations of CD45pos leukocytes compared to other groups ( P <0.05). The correlation analysis showed the presence of a positive linear relationship between CD45pos leukocytes and the percentage of immature germ elements (r = 0.88; P <0.05) and between CD45pos leukocytes and the percentage of spermatozoa with phosphatidylserine externalisation (r = 0.90; P <0.05) as well as a negative linear relationship between the percentage of spermatozoa with normal morphology and the seminal CD45pos leukocyte concentrations ( r = −0.75; P <0.05). The results of this study showed that patients with low testicular volume (<10 cm3) have significantly increased CD45pos leukocyte concentrations associated with increased percentages of immature germ elements, spermatozoa with signs of early apoptosis and spermatozoa with abnormal morphology
Structure and Biological Properties of Ribosome-Inactivating Proteins and Lectins from Elder (Sambucus nigra L.) Leaves
Ribosome-inactivating proteins (RIPs) are a group of proteins with rRNA N-glycosylase activity that catalyze the removal of a specific adenine located in the sarcin-ricin loop of the large ribosomal RNA, which leads to the irreversible inhibition of protein synthesis and, consequently, cell death. The case of elderberry (Sambucus nigra L.) is unique, since more than 20 RIPs and related lectins have been isolated and characterized from the flowers, seeds, fruits, and bark of this plant. However, these kinds of proteins have never been isolated from elderberry leaves. In this work, we have purified RIPs and lectins from the leaves of this shrub, studying their main physicochemical characteristics, sequences, and biological properties. In elderberry leaves, we found one type 2 RIP and two related lectins that are specific for galactose, four type 2 RIPs that fail to agglutinate erythrocytes, and one type 1 RIP. Several of these proteins are homologous to others found elsewhere in the plant. The diversity of RIPs and lectins in the different elderberry tissues, and the different biological activities of these proteins, which have a high degree of homology with each other, constitute an excellent source of proteins that are of great interest in diagnostics, experimental therapy, and agriculture
Cystatin B Involvement in Synapse Physiology of Rodent Brains and Human Cerebral Organoids
Cystatin B (CSTB) is a ubiquitous protein belonging to a superfamily of protease inhibitors. CSTB may play a critical role in brain physiology because its mutations cause progressive myoclonic epilepsy-1A (EPM1A), the most common form of progressive myoclonic epilepsy. However, the molecular mechanisms underlying the role of CSTB in the central nervous system (CNS) are largely unknown. To investigate the possible involvement of CSTB in the synaptic plasticity, we analyzed its expression in synaptosomes as a model system in studying the physiology of the synaptic regions of the CNS. We found that CSTB is not only present in the synaptosomes isolated from rat and mouse brain cortex, but also secreted into the medium in a depolarization-controlled manner. In addition, using biorthogonal noncanonical amino acid tagging (BONCAT) procedure, we demonstrated, for the first time, that CSTB is locally synthesized in the synaptosomes. The synaptic localization of CSTB was confirmed in a human 3D model of cortical development, namely cerebral organoids. Altogether, these results suggest that CSTB may play a role in the brain plasticity and open a new perspective in studying the involvement of CSTB deregulation in neurodegenerative and neuropsychiatric diseases
Structural and functional characterization of the cytotoxic protein ledodin, an atypical ribosome‐inactivating protein from shiitake mushroom (Lentinula edodes)
Producción CientíficaWe have purified ledodin, a cytotoxic 22-kDa protein from shiitake mushroom (Lentinula edodes) consisting of a 197 amino acid chain. Ledodin possessed N-glycosylase activity on the sarcin-ricin loop of mammalian 28S rRNA and inhibited protein synthesis. However, it was not active against insect, fungal and bacterial ribosomes. In vitro and in silico studies suggested that ledodin exhibits a catalytic mechanism like that of DNA glycosylases and plant ribosome-inactivating proteins. However, the sequence and structure of ledodin was not related to any protein of known function, although ledodin-homologous sequences were found in the genome of several species of fungi, some edible, belonging to different orders of the class Agaricomycetes. Therefore, ledodin could be the first of a new family of enzymes widely distributed among this class of basidiomycetes. The interest of these proteins lies both, in the fact that they can be a toxic agent of some edible mushrooms and in their application in medicine and biotechnology.Junta de Castilla y León (Consejería de Sanidad - grants BIO39/VA39/14 and BIO/VA17/15)Junta de Castilla y León (Consejería de Educación - grant VA033G19)NUTRABEST PON I&C 2014–2020 Prog.n. F/200050/01-03/X4
Universal proposal strategies of anti-HPV vaccination for adolescents: comparative analysis between school-based and clinic immunization programs.
INTRODUCTION – A promising approach in order to increase adolescents’ adhesion to anti-HPV immunization is the administration of the vaccines within educational institutes. Taranto Local Health Unit experimented two different strategies of universal proposal for the vaccination of 12 year olds: the first is in the traditional call from the clinic while the second involves schools within the territory. The objective of the study is to evaluate the results of these strategies on different genders and different urban contests in order to identify an effective process that can lead to optimal coverage.METHODS – In order to estimate the number of anti-HPV doses administrated to the adolescents of the 2003 cohort, data from the Puglia region’s computerized vaccine registry have been used. Coverages of the anti-HPV vaccinations have been analyzed, dividing these by gender, proposal strategy and district size. Analyses were performed by using STATA SE 14.RESULTS – The multiple logistic regression underlines that female sex (OR = 3.2; p < 0.01), living in a small community (OR = 1.3; p < 0.01) and school vaccination program (OR = 2; p < 0.01) increase the probability of completing the anti-HPV vaccination cycle in adolescents. The comparative evaluation of the anti-HPV coverage based on proposal strategies, shows that the school vaccination leads to significantly better results compared to the clinic vaccination, for all the groups taken into account (overall 72.3% vs 55.6%)CONCLUSIONS – The involvement of educational institutes can define a winning organization model in order to obtain a bigger adhesion of adolescents to immunization programs, especially for the male sex and in bigger communities
Insights into the Interaction Mechanism of DTP3 with MKK7 by Using STD-NMR and Computational Approaches
GADD45β/MKK7 complex is a non-redundant, cancer cell-restricted survival module downstream of the NF-kB survival pathway, and it has a pathogenically critical role in multiple myeloma, an incurable malignancy of plasma cells. The first-in-class GADD45β/MKK7 inhibitor DTP3 effectively kills MM cells expressing its molecular target, both in vitro and in vivo, by inducing MKK7/JNK-dependent apoptosis with no apparent toxicity to normal cells. DTP3 combines favorable drug-like properties, with on-target-specific pharmacology, resulting in a safe and cancer-selective therapeutic effect; however, its mode of action is only partially understood. In this work, we have investigated the molecular determinants underlying the MKK7 interaction with DTP3 by combining computational, NMR, and spectroscopic methods. Data gathered by fluorescence quenching and computational approaches consistently indicate that the N-terminal region of MKK7 is the optimal binding site explored by DTP3. These findings further the understanding of the selective mode of action of GADD45β/MKK7 inhibitors and inform potential mechanisms of drug resistance. Notably, upon validation of the safety and efficacy of DTP3 in human trials, our results could also facilitate the development of novel DTP3-like therapeutics with improved bioavailability or the capacity to bypass drug resistance
Nusinersen mitigates neuroinflammation in severe spinal muscular atrophy patients
Background: Neuroinflammation contributes to the onset and progression of neurodegenerative diseases, but has not been specifically investigated in patients affected by severe and milder forms of spinal muscular atrophy (SMA). Methods: In this two-center retrospective study, we investigated signatures of neuroinflammation in forty-eight pediatric male and female SMA1 (n = 18), male and female SMA2 (n = 19), and female SMA3 (n = 11) patients, as well as in a limited number of male and female non-neurological control subjects (n = 4). We employed a Bio-Plex multiplex system based on xMAP technology and performed targeted quantitative analysis of a wide range of pro- and anti-inflammatory cytokines (chemokines, interferons, interleukins, lymphokines and tumor necrosis factors) and neurotrophic factors in the cerebrospinal fluid (CSF) of the study cohort before and after Nusinersen treatment at loading and maintenance stages. Results: We find a significant increase in the levels of several pro-inflammatory cytokines (IL-6, IFN-γ, TNF-α, IL-2, IL-8, IL-12, IL-17, MIP-1α, MCP-1, and Eotaxin) and neurotrophic factors (PDGF-BB and VEGF) in the CSF of SMA1 patients relative to SMA2 and SMA3 individuals, who display levels in the range of controls. We also find that treatment with Nusinersen significantly reduces the CSF levels of some but not all of these neuroinflammatory molecules in SMA1 patients. Conversely, Nusinersen increases the CSF levels of proinflammatory G-CSF, IL-8, MCP-1, MIP-1α, and MIP-1β in SMA2 patients and decreases those of anti-inflammatory IL-1ra in SMA3 patients. Conclusions: These findings highlight signatures of neuroinflammation that are specifically associated with severe SMA and the neuro-immunomodulatory effects of Nusinersen therapy
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