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1.
J Cell Mol Med ; 28(6): e18161, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38445787

RESUMO

Cisplatin is an antimitotic drug able to cause acute and chronic gastrointestinal side effects. Acute side effects are attributable to mucositis while chronic ones are due to neuropathy. Cisplatin has also antibiotic properties inducing dysbiosis which enhances the inflammatory response, worsening local damage. Thus, a treatment aimed at protecting the microbiota could prevent or reduce the toxicity of chemotherapy. Furthermore, since a healthy microbiota enhances the effects of some chemotherapeutic drugs, prebiotics could also improve this drug effectiveness. We investigated whether chronic cisplatin administration determined morphological and functional alterations in mouse proximal colon and whether a diet enriched in prebiotics had protective effects. The results showed that cisplatin caused lack of weight gain, increase in kaolin intake, decrease in stool production and mucus secretion. Prebiotics prevented increases in kaolin intake, changes in stool production and mucus secretion, but had no effect on the lack of weight gain. Moreover, cisplatin determined a reduction in amplitude of spontaneous muscular contractions and of Connexin (Cx)43 expression in the interstitial cells of Cajal, changes that were partially prevented by prebiotics. In conclusion, the present study shows that daily administration of prebiotics, likely protecting the microbiota, prevents most of the colonic cisplatin-induced alterations.


Assuntos
Cisplatino , Prebióticos , Animais , Camundongos , Cisplatino/efeitos adversos , Caulim , Aumento de Peso , Colo
2.
Food Chem ; 438: 138037, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38011789

RESUMO

Phytochemical-rich antioxidant extracts were obtained from Ascophyllum nodosum (AN) using microwave-assisted extraction (MAE). Critical extraction factors such as time, pressure, and ethanol concentration were optimized by response surface methodology with a circumscribed central composite design. Under the optimal MAE conditions (3 min, 10.4 bar, 46.8 % ethanol), the maximum recovery of phytochemical compounds (polyphenols and fucoxanthin) with improved antioxidant activity from AN was obtained. In addition, the optimized AN extract showed significant biological activities as it was able to scavenge reactive oxygen and nitrogen species, inhibit central nervous system-related enzymes, and exhibit cytotoxic activity against different cancer cell lines. In addition, the optimized AN extract showed antimicrobial, and anti-quorum sensing activities, indicating that this extract could offer direct and indirect protection against infection by pathogenic microorganisms. This work demonstrated that the sustainably obtained AN extract could be an emerging, non-toxic, and natural ingredient with potential to be included in different applications.


Assuntos
Ascophyllum , Micro-Ondas , Antioxidantes/farmacologia , Antioxidantes/química , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Etanol/química
4.
Eur J Neurol ; 29(3): 890-894, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34679240

RESUMO

BACKGROUND AND PURPOSE: The core manifestations of leucine-rich glioma-inactivated 1 (LGI1) autoantibody-mediated encephalitis are limbic encephalitis and faciobrachial dystonic seizures. Agrypnia excitata (AE) is a rare syndrome characterized by sleep-wake cycle disruption, autonomic hyperactivation and episodes of oneiric stupor. Only a few diseases are known to present with AE. An autoimmune etiology must be considered when accompanied by neuromyotonia. A case of anti-LGI1 encephalitis presenting with AE is reported. METHODS: Detailed clinical, video-polysomnographic, laboratory, radiological and long-term follow-up assessments were performed. RESULTS: A previously healthy 58-year-old man was referred for a rapidly progressive change in mental status, characterized by persistent drowsiness and confusion, accompanied by frequent episodes of unconscious gestures ranging from simple stereotyped movements to more complex actions mimicking various daily activities. Other symptoms included tachycardia, hyperhidrosis, mild hyponatremia, rare faciobrachial dystonic seizures, and a single generalized tonic-clonic seizure, but no neuromyotonia. Prolonged video-polysomnography excluded epileptic activity and showed continuous monomorphic slowing of background activity not consistent with a regular wakefulness or sleep state. A brain magnetic resonance imaging scan was unremarkable. Brain fluorodeoxyglucose positron emission tomography revealed hypermetabolism of the hippocampi, amygdala and basal ganglia. Anti-LGI1 antibodies were detected in the cerebrospinal fluid. The sleep disorder resolved progressively after starting immunotherapy. CONCLUSIONS: Agrypnia excitata can be a dominant, treatable manifestation of anti-LGI1 encephalitis. Oneiric stupor episodes are a useful clinical feature for establishing diagnostic suspicion and could provide a window to understanding the mechanisms behind some movement disorders in autoimmune encephalitis.


Assuntos
Encefalite , Glioma , Doença de Hashimoto , Encefalite Límbica , Autoanticorpos , Encefalite/complicações , Encefalite/diagnóstico , Humanos , Leucina/uso terapêutico , Encefalite Límbica/complicações , Encefalite Límbica/diagnóstico , Encefalite Límbica/terapia , Masculino , Pessoa de Meia-Idade
5.
Structure ; 30(2): 229-239.e5, 2022 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-34800372

RESUMO

Cellular FLICE-like inhibitory protein (cFLIP) is a member of the Death Domain superfamily with pivotal roles in many cellular processes and disease states, including cancer and autoimmune disorders. In the context of the death-inducing signaling complex (DISC), cFLIP isoforms regulate extrinsic apoptosis by controlling procaspase-8 activation. The function of cFLIP is mediated through a series of protein-protein interactions, engaging the two N-terminal death effector domains (DEDs). Here, we solve the structure of an engineered DED1 domain of cFLIP using solution nuclear magnetic resonance (NMR) and we define the interaction with FADD and calmodulin, protein-protein interactions that regulate the function of cFLIP in the DISC. cFLIP DED1 assumes a canonical DED fold characterized by six α helices and is able to bind calmodulin and FADD through two separate interfaces. Our results clearly demonstrate the role of DED1 in the cFLIP/FADD association and contribute to the understanding of the assembly of DISC filaments.


Assuntos
Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/química , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/metabolismo , Calmodulina/metabolismo , Proteína de Domínio de Morte Associada a Fas/metabolismo , Engenharia de Proteínas/métodos , Sítios de Ligação , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/genética , Dicroísmo Circular , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Ligação Proteica , Domínios Proteicos , Mapas de Interação de Proteínas , Estrutura Secundária de Proteína
6.
Traffic ; 22(1-2): 23-37, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33225481

RESUMO

Autophagy-linked FYVE protein (ALFY) is a large, multidomain protein involved in the degradation of protein aggregates by selective autophagy. The C-terminal FYVE domain of ALFY has been shown to bind phosphatidylinositol 3-phosphate (PI(3)P); however, ALFY only partially colocalizes with other FYVE domains in cells. Thus, we asked if the FYVE domain of ALFY has distinct membrane binding properties compared to other FYVE domains and whether these properties might affect its function in vivo. We found that the FYVE domain of ALFY binds weakly to PI(3)P containing membranes in vitro. This weak binding is the result of a highly conserved glutamic acid within the membrane insertion loop in the FYVE domain of ALFY that is not present in any other human FYVE domain. In addition, not only does this glutamic acid reduce binding to membranes in vitro and inhibits its targeting to membranes in vivo, but it is also important for the ability of ALFY to clear protein aggregates.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Ácido Glutâmico , Proteínas Relacionadas à Autofagia , Humanos , Fosfatos de Fosfatidilinositol
7.
Neurogastroenterol Motil ; 33(3): e13993, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33020982

RESUMO

BACKGROUND AND AIM: Muscularis macrophages (MMs) not only mediate the innate immunity, but also functionally interact with cells important for gastrointestinal motility. The aim of this study was to determine the spatial relationship and types of contacts between the MMs and neighboring cells in the muscularis propria of human and mouse stomach, small intestine, and large intestine. METHODS: The distribution and morphology of MMs and their contacts with other cells were investigated by immunohistochemistry and transmission electron microscopy. KEY RESULTS: Immunohistochemistry showed variable shape and number of MMs according to their location in different portions of the muscle coat. By double labeling, a close association between MMs and neighboring cells, that is, neurons, smooth muscle cells, interstitial cells of Cajal (ICCs), telocytes (TCs)/PDGFRα-positive cells, was seen. Electron microscopy demonstrated that in the muscle layers of both animal species, MMs have similar ultrastructural features and have specialized cell-to-cell contacts with smooth muscle cells and TCs/PDGFRα-positive cells but not with ICCs and enteric neurons. CONCLUSION & INFERENCES: This study describes varying patterns of distribution of MMs between different regions of the gut, and reports the presence of distinct and extended cell-to-cell contacts between MMs and smooth muscle cells and between MMs and TCs/PDGFRα-positive cells. In contrast, MMs, although close to ICCs and nerve elements, did not make contact with them. These findings indicate specialized and variable roles for MMs in the modulation of gastrointestinal motility whose significance should be more closely investigated in normal and pathological conditions.


Assuntos
Mucosa Gástrica/citologia , Junções Intercelulares/ultraestrutura , Mucosa Intestinal/citologia , Macrófagos/citologia , Miócitos de Músculo Liso/citologia , Telócitos/citologia , Animais , Comunicação Celular , Sistema Nervoso Entérico , Feminino , Mucosa Gástrica/metabolismo , Mucosa Gástrica/ultraestrutura , Humanos , Células Intersticiais de Cajal/citologia , Células Intersticiais de Cajal/metabolismo , Células Intersticiais de Cajal/ultraestrutura , Mucosa Intestinal/metabolismo , Mucosa Intestinal/ultraestrutura , Macrófagos/metabolismo , Macrófagos/ultraestrutura , Masculino , Camundongos , Microscopia Eletrônica de Transmissão , Pessoa de Meia-Idade , Miócitos de Músculo Liso/metabolismo , Miócitos de Músculo Liso/ultraestrutura , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/metabolismo , Telócitos/metabolismo , Telócitos/ultraestrutura
8.
J Cell Mol Med ; 23(6): 4076-4087, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30945429

RESUMO

Urothelium and Lamina Propria (LP) are considered an integrate sensory system which is able to control the detrusor activity. Complete supra-sacral spinal cord lesions cause Neurogenic Detrusor Overactivity (NDO) whose main symptoms are urgency and incontinence. NDO therapy at first consists in anti-muscarinic drugs; secondly, in intra-vesical injection of botulinum toxin. However, with time, all the patients become insensitive to the drugs and decide for cystoplastic surgery. With the aim to get deeper in both NDO and drug's efficacy lack pathogenesis, we investigated the innervation, muscular and connective changes in NDO bladders after surgery by using morphological and quantitative methodologies. Bladder innervation showed a significant global loss associated with an increase in the nerve endings located in the upper LP where a neurogenic inflammation was also present. Smooth muscle cells (SMC) anomalies and fibrosis were found in the detrusor. The increased innervation in the ULP is suggestive for a sprouting and could condition NDO evolution and drug efficacy length. Denervation might cause the SMC anomalies responsible for the detrusor altered contractile activity and intra-cellular traffic and favour the appearance of fibrosis. Inflammation might accelerate these damages. From the clinical point of view, an early anti-inflammatory treatment could positively influence the disease fate.


Assuntos
Inflamação Neurogênica/patologia , Bexiga Urinária Hiperativa/patologia , Bexiga Urinária/patologia , Adulto , Toxinas Botulínicas Tipo A/uso terapêutico , Feminino , Humanos , Masculino , Mucosa/efeitos dos fármacos , Mucosa/patologia , Contração Muscular/efeitos dos fármacos , Contração Muscular/fisiologia , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/patologia , Inflamação Neurogênica/tratamento farmacológico , Bexiga Urinária/efeitos dos fármacos , Bexiga Urinária Hiperativa/tratamento farmacológico , Incontinência Urinária/tratamento farmacológico , Incontinência Urinária/patologia , Urotélio/patologia
10.
Biosci Rep ; 38(4)2018 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-29472314

RESUMO

Protein-protein interactions have become attractive targets for both experimental and therapeutic interventions. The PSD-95/Dlg1/ZO-1 (PDZ) domain is found in a large family of eukaryotic scaffold proteins that plays important roles in intracellular trafficking and localization of many target proteins. Here, we seek inhibitors of the PDZ protein that facilitates post-endocytic degradation of the cystic fibrosis (CF) transmembrane conductance regulator (CFTR): the CFTR-associated ligand (CAL). We develop and validate biochemical screens and identify methyl-3,4-dephostatin (MD) and its analog ethyl-3,4-dephostatin (ED) as CAL PDZ inhibitors. Depending on conditions, MD can bind either covalently or non-covalently. Crystallographic and NMR data confirm that MD attacks a pocket at a site distinct from the canonical peptide-binding groove, and suggests an allosteric connection between target residue Cys319 and the conserved Leu291 in the GLGI motif. MD and ED thus appear to represent the first examples of small-molecule allosteric regulation of PDZ:peptide affinity. Their mechanism of action may exploit the known conformational plasticity of the PDZ domains and suggests that allosteric modulation may represent a strategy for targeting of this family of protein-protein binding modules.


Assuntos
Sítio Alostérico/efeitos dos fármacos , Proteínas de Transporte/metabolismo , Hidroquinonas/química , Hidroquinonas/farmacologia , Proteínas de Membrana/metabolismo , Domínios PDZ/efeitos dos fármacos , Proteínas Adaptadoras de Transdução de Sinal , Regulação Alostérica/efeitos dos fármacos , Proteínas de Transporte/antagonistas & inibidores , Proteínas de Transporte/química , Cristalografia por Raios X , Cisteína/química , Cisteína/metabolismo , Proteínas da Matriz do Complexo de Golgi , Humanos , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/química , Proteínas de Membrana Transportadoras , Metilação , Simulação de Acoplamento Molecular , Ressonância Magnética Nuclear Biomolecular
11.
Front Plant Sci ; 8: 1711, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29075273

RESUMO

In vascular plants the cell-to-cell interactions coordinating morphogenetic and physiological processes are mediated, among others, by the action of hormones, among which also short mobile peptides were recognized to have roles as signals. Such peptide hormones (PHs) are involved in defense responses, shoot and root growth, meristem homeostasis, organ abscission, nutrient signaling, hormone crosstalk and other developmental processes and act as both short and long distant ligands. In this work, the function of CTG134, a peach gene encoding a ROOT GROWTH FACTOR/GOLVEN-like PH expressed in mesocarp at the onset of ripening, was investigated for its role in mediating an auxin-ethylene crosstalk. In peach fruit, where an auxin-ethylene crosstalk mechanism is necessary to support climacteric ethylene synthesis, CTG134 expression peaked before that of ACS1 and was induced by auxin and 1-methylcyclopropene (1-MCP) treatments, whereas it was minimally affected by ethylene. In addition, the promoter of CTG134 fused with the GUS reporter highlighted activity in plant parts in which the auxin-ethylene interplay is known to occur. Arabidopsis and tobacco plants overexpressing CTG134 showed abnormal root hair growth, similar to wild-type plants treated with a synthetic form of the sulfated peptide. Moreover, in tobacco, lateral root emergence and capsule size were also affected. In Arabidopsis overexpressing lines, molecular surveys demonstrated an impaired hormonal crosstalk, resulting in a re-modulated expression of a set of genes involved in both ethylene and auxin synthesis, transport and perception. These data support the role of pCTG134 as a mediator in an auxin-ethylene regulatory circuit and open the possibility to exploit this class of ligands for the rational design of new and environmental friendly agrochemicals able to cope with a rapidly changing environment.

12.
Biomol NMR Assign ; 11(2): 211-214, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28766175

RESUMO

Autophagy is a catabolic cellular process that targets cytosolic material, including mitochondria, to the vacuole or lysosomes for degradation. The selective degradation of mitochondria by autophagy is termed mitophagy. Dysfunctional mitophagy, which leads to the accumulation of damaged mitochondria, has been implicated in Parkinson's disease, cancer, cardiac disease and metabolic disease. In Saccharomyces cerevisiae, mitophagy is initiated by the autophagy receptor Atg32, an outer mitochondrial membrane protein. A lack of structural information for Atg32 has hindered our understanding of the molecular mechanisms of mitophagy initiation. To gain new structural insight into Atg32, we have identified the location of a structured domain within the cytosolic region of Atg32 and completed the backbone and side chain resonance assignments for this domain.


Assuntos
Proteínas Relacionadas à Autofagia/química , Ressonância Magnética Nuclear Biomolecular , Receptores Citoplasmáticos e Nucleares/química , Proteínas de Saccharomyces cerevisiae/química , Saccharomyces cerevisiae , Domínios Proteicos
13.
J Cell Mol Med ; 21(4): 735-745, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27866394

RESUMO

Otilonium bromide (OB) is a spasmolytic drug successfully used for the treatment of irritable bowel syndrome (IBS). Its efficacy has been attributed to the block of L- and T-type Ca2+ channels and muscarinic and tachykinin receptors in the smooth muscle. Furthermore, in healthy rats, repeated OB administration modified neurotransmitter expression and function suggesting other mechanisms of action. On this basis, we investigated whether repeated OB treatment prevented the functional and neurochemical changes observed in the colon of rats underwent to wrap restrain stress (WRS) a psychosocial stressor considered suitable to reproduce the main IBS signs and symptoms. In control, WRS and OB/WRS rats functional parameters were measured in vivo and morphological investigations were done ex vivo in the colon. The results showed that OB counteracts most of the neurotransmitters changes caused by WRS. In particular, the drug prevents the decrease in SP-, NK1r-, nNOS-, VIP-, and S100ß-immunoreactivity (IR) and the increase in CGRP-, and CRF1r-IR. On the contrary, OB does not affect the increase in CRF2r-IR neurons observed in WRS rats and does not interfere with the mild mucosal inflammation due to WRS. Finally, OB per se increases the Mr2 expression in the muscle wall and decreases the number of the myenteric ChAT-IR neurons. Functional findings show a significantly reduction in the number of spontaneous abdominal contraction in OB treated rats. The ability of OB to block L-type Ca2+ channels, also expressed by enteric neurons, might represent a possible mechanism through which OB exerts its actions.


Assuntos
Colo/metabolismo , Neurotransmissores/metabolismo , Compostos de Amônio Quaternário/administração & dosagem , Compostos de Amônio Quaternário/uso terapêutico , Estresse Psicológico/tratamento farmacológico , Estresse Psicológico/metabolismo , Animais , Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Colo/efeitos dos fármacos , Colo/patologia , Células Intersticiais de Cajal/efeitos dos fármacos , Células Intersticiais de Cajal/metabolismo , Células Intersticiais de Cajal/patologia , Masculino , Mucosa/efeitos dos fármacos , Mucosa/patologia , Músculo Liso/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-kit/metabolismo , Compostos de Amônio Quaternário/farmacologia , Ratos Wistar , Receptor Muscarínico M2/metabolismo , Receptores de Hormônio Liberador da Corticotropina/metabolismo , Receptores da Neurocinina-1/metabolismo , Peptídeo Intestinal Vasoativo/metabolismo
14.
Blood Cells Mol Dis ; 57: 71-3, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26852659

RESUMO

Umbilical cord blood (UCB) represents a source of hematopoietic stem cells for patients lacking a suitably matched and readily available related or unrelated stem cell donor. As UCB transplantation from compatible sibling provides good results in children therefore directed sibling UCB collection and banking is indicated in family who already have a child with a disease potentially treatable with an allogeneic hematopoietic stem cell transplantation. Particularly, related UCB collection is recommended when the patients urgently need a transplantation. To provide access to all patients in need, we developed a "Sibling cord blood donor program for hematopoietic cell transplantation". Here we report results of this project started 20years ago. To date, in this study a total of 194 families were enrolled, a total of 204 UCB samples were successfully collected and 15 pediatric patients have been transplanted. Recently, some authors have suggested novel role for UCB other than in the transplantation setting. Therefore, future studies in the immunotherapy and regenerative medicine areas could expand indication for sibling directed UCB collection.


Assuntos
Bancos de Sangue/história , Transplante de Células-Tronco de Sangue do Cordão Umbilical/história , Sangue Fetal/citologia , Transplante de Células-Tronco Hematopoéticas/história , Células-Tronco Hematopoéticas/citologia , Adolescente , Criança , Pré-Escolar , Transplante de Células-Tronco de Sangue do Cordão Umbilical/métodos , Feminino , Sangue Fetal/imunologia , Neoplasias Hematológicas/imunologia , Neoplasias Hematológicas/patologia , Neoplasias Hematológicas/terapia , Transplante de Células-Tronco Hematopoéticas/métodos , Células-Tronco Hematopoéticas/imunologia , Hemoglobinopatias/imunologia , Hemoglobinopatias/patologia , Hemoglobinopatias/terapia , História do Século XX , História do Século XXI , Humanos , Lactente , Itália , Masculino , Irmãos , Doadores não Relacionados
15.
PLoS One ; 10(11): e0141692, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26529318

RESUMO

Overexpression of the cellular FLICE-like inhibitory protein (cFLIP) has been reported in a number of tumor types. As an inactive procaspase-8 homologue, cFLIP is recruited to the intracellular assembly known as the Death Inducing Signaling Complex (DISC) where it inhibits apoptosis, leading to cancer cell proliferation. Here we characterize the molecular details of the interaction between cFLIPL and calmodulin, a ubiquitous calcium sensing protein. By expressing the individual domains of cFLIPL, we demonstrate that the interaction with calmodulin is mediated by the N-terminal death effector domain (DED1) of cFLIPL. Additionally, we mapped the interaction to a specific region of the C-terminus of DED1, referred to as DED1 R4. By designing DED1/DED2 chimeric constructs in which the homologous R4 regions of the two domains were swapped, calmodulin binding properties were transferred to DED2 and removed from DED1. Furthermore, we show that the isolated DED1 R4 peptide binds to calmodulin and solve the structure of the peptide-protein complex using NMR and computational refinement. Finally, we demonstrate an interaction between cFLIPL and calmodulin in cancer cell lysates. In summary, our data implicate calmodulin as a potential player in DISC-mediated apoptosis and provide evidence for a specific interaction with the DED1 of cFLIPL.


Assuntos
Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/química , Calmodulina/química , Apoptose , Sítios de Ligação , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/genética , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/metabolismo , Calmodulina/genética , Calmodulina/metabolismo , Linhagem Celular Tumoral , Humanos , Estrutura Terciária de Proteína , Homologia Estrutural de Proteína
16.
Sci Rep ; 5: 9893, 2015 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-25962125

RESUMO

Recombinant soluble TRAIL and agonistic antibodies against TRAIL receptors (DR4 and DR5) are currently being created for clinical cancer therapy, due to their selective killing of cancer cells and high safety characteristics. However, resistance to TRAIL and other targeted therapies is an important issue facing current cancer research field. An attractive strategy to sensitize resistant malignancies to TRAIL-induced cell death is the design of small molecules that target and promote caspase 8 activation. For the first time, we describe the discovery and characterization of a small molecule that directly binds caspase 8 and enhances its activation when combined with TRAIL, but not alone. The molecule was identified through an in silico chemical screen for compounds with affinity for the caspase 8 homodimer's interface. The compound was experimentally validated to directly bind caspase 8, and to promote caspase 8 activation and cell death in single living cells or population of cells, upon TRAIL stimulation. Our approach is a proof-of-concept strategy leading to the discovery of a novel small molecule that not only stimulates TRAIL-induced apoptosis in cancer cells, but may also provide insights into the structure-function relationship of caspase 8 homodimers as putative targets in cancer.


Assuntos
Apoptose/efeitos dos fármacos , Caspase 8/química , Caspase 8/metabolismo , Ativadores de Enzimas , Proteínas de Neoplasias/metabolismo , Neoplasias/tratamento farmacológico , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Apoptose/genética , Caspase 8/genética , Ativação Enzimática/efeitos dos fármacos , Ativação Enzimática/genética , Ativadores de Enzimas/química , Ativadores de Enzimas/farmacologia , Células HeLa , Humanos , Células Jurkat , Células K562 , Proteínas de Neoplasias/agonistas , Proteínas de Neoplasias/genética , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patologia , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/agonistas , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/genética , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/genética
17.
Gastroenterology ; 149(1): 56-66.e5, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25863217

RESUMO

BACKGROUND & AIMS: Chronic unexplained nausea and vomiting (CUNV) is a debilitating disease of unknown cause. Symptoms of CUNV substantially overlap with those of gastroparesis, therefore the diseases may share pathophysiologic features. We investigated this hypothesis by quantifying densities of interstitial cells of Cajal (ICCs) and mapping slow-wave abnormalities in patients with CUNV vs controls. METHODS: Clinical data and gastric biopsy specimens were collected from 9 consecutive patients with at least 6 months of continuous symptoms of CUNV but normal gastric emptying who were treated at the University of Mississippi Medical Center, and from 9 controls (individuals free of gastrointestinal disease or diabetes). ICCs were counted and ultrastructural analyses were performed on tissue samples. Slow-wave propagation profiles were defined by high-resolution electrical mapping (256 electrodes; 36 cm(2)). Results from patients with CUNV were compared with those of controls as well as patients with gastroparesis who were studied previously by identical methods. RESULTS: Patients with CUNV had fewer ICCs than controls (mean, 3.5 vs 5.6 bodies/field, respectively; P < .05), with mild ultrastructural abnormalities in the remaining ICCs. Slow-wave dysrhythmias were identified in all 9 subjects with CUNV vs only 1 of 9 controls. Dysrhythmias included abnormalities of initiation (stable ectopic pacemakers, unstable focal activities) and conduction (retrograde propagation, wavefront collisions, conduction blocks, and re-entry), operating across bradygastric, normal (range, 2.4-3.7 cycles/min), and tachygastric frequencies; dysrhythmias showed velocity anisotropy (mean, 3.3 mm/s longitudinal vs 7.6 mm/s circumferential; P < .01). ICCs were less depleted in patients with CUNV than in those with gastroparesis (mean, 3.5 vs 2.3 bodies/field, respectively; P < .05), but slow-wave dysrhythmias were similar between groups. CONCLUSIONS: This study defined cellular and bioelectrical abnormalities in patients with CUNV, including the identification of slow-wave re-entry. Pathophysiologic features of CUNV were observed to be similar to those of gastroparesis, indicating that they could be spectra of the same disorder. These findings offer new insights into the pathogenesis of CUNV and may help to inform future treatments.


Assuntos
Eletromiografia , Gastroenteropatias/diagnóstico , Motilidade Gastrointestinal , Células Intersticiais de Cajal , Adulto , Idoso , Estudos de Casos e Controles , Eletrodiagnóstico , Feminino , Gastroenteropatias/complicações , Gastroenteropatias/patologia , Gastroenteropatias/fisiopatologia , Gastroparesia/etiologia , Gastroparesia/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Náusea/etiologia , Vômito/etiologia , Adulto Jovem
18.
Ann Glob Health ; 81(6): 803-13, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-27108147

RESUMO

BACKGROUND: Diabetes is a significant health problem in Italy as in other western countries. OBJECTIVE: To review available epidemiological data and the legislative framework for diabetes care in Italy. METHODS: Review of Italian Health Ministry's official documents and analysis of epidemiological data published by Italian Scientific Societies. FINDINGS: Diabetes affects more than 5% of the Italian population. The expenditures for the care of people with diabetes are about €10 billion ($US 11 billion) a year and are increasing over time. Italian law regulates the clinical care of people with diabetes and creates a clinical framework involving medical organizations, prevention programs, personnel training, and legal protection. The National Health Program is structured in essential levels of assistance that can be defined differently in the various regions. In 2013, the "National Diabetes Plan," defining priority areas for intervention, was approved and represents the main regulatory tool for the management of diabetes within the Italian National Health Service. In Italy, the status of diabetes care is being monitored using the data from 2 permanent observatories: the ARNO Observatory Diabetes and the Associazione Medici Diabetologi Annals. CONCLUSIONS: A comprehensive approach to diabetes is offered to all citizens, consonant with the constitutionally guaranteed right to health. However, this important effort translates into a relevant financial burden for the National Health Service.


Assuntos
Diabetes Mellitus/economia , Diabetes Mellitus/terapia , Gastos em Saúde/estatística & dados numéricos , Recursos em Saúde , Programas Nacionais de Saúde/economia , Análise Custo-Benefício , Diabetes Mellitus/epidemiologia , Humanos , Itália , Prevalência , Indicadores de Qualidade em Assistência à Saúde , Resultado do Tratamento
19.
J Biol Chem ; 290(5): 2879-87, 2015 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-25492869

RESUMO

The regulation of the cell cycle by the ubiquitin-proteasome system is dependent on the activity of E3 ligases. Skp2 (S-phase kinase associated protein-2) is the substrate recognition subunit of the E3 ligase that ubiquitylates the cell cycle inhibitors p21(cip1) and p27(kip1) thus promoting cell cycle progression. Increased expression of Skp2 is frequently observed in diseases characterized by excessive cell proliferation, such as cancer and neointima hyperplasia. The stability and cellular localization of Skp2 are regulated by Akt, but the molecular mechanisms underlying these effects remain only partly understood. The scaffolding protein Ezrin-Binding Phosphoprotein of 50 kDa (EBP50) contains two PDZ domains and plays a critical role in the development of neointimal hyperplasia. Here we report that EBP50 directly binds Skp2 via its first PDZ domain. Moreover, EBP50 is phosphorylated by Akt on Thr-156 within the second PDZ domain, an event that allosterically promotes binding to Skp2. The interaction with EBP50 causes cytoplasmic localization of Skp2, increases Skp2 stability and promotes proliferation of primary vascular smooth muscle cells. Collectively, these studies define a novel regulatory mechanism contributing to aberrant cell growth and highlight the importance of scaffolding function of EBP50 in Akt-dependent cell proliferation.


Assuntos
Fosfoproteínas/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Quinases Associadas a Fase S/metabolismo , Trocadores de Sódio-Hidrogênio/metabolismo , Animais , Proliferação de Células , Células Cultivadas , Humanos , Camundongos , Fosfoproteínas/química , Fosforilação , Ligação Proteica , Estabilidade Proteica , Proteínas Proto-Oncogênicas c-akt/química , Proteínas Quinases Associadas a Fase S/química , Trocadores de Sódio-Hidrogênio/química
20.
J Pept Sci ; 21(3): 236-42, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25522925

RESUMO

The JC polyomavirus (JCPyV) infects approximately 50% of the human population. In healthy individuals, the infection remains dormant and asymptomatic, but in immuno-suppressed patients, it can cause progressive multifocal leukoencephalopathy (PML), a potentially fatal demyelinating disease. Currently, there are no drugs against JCPyV infection nor for the treatment of PML. Here, we report the development of small-molecule inhibitors of JCPyV that target the initial interaction between the virus and host cell and thereby block viral entry. Utilizing a combination of computational and NMR-based screening techniques, we target the LSTc tetrasaccharide binding site within the VP1 pentameric coat protein of JCPyV. Four of the compounds from the screen effectively block viral infection in our in vitro assays using SVG-A cells. For the most potent compound, we used saturation transfer difference NMR to determine the mode of binding to purified pentamers of JCPyV VP1. Collectively, these results demonstrate the viability of this class of compounds for eventual development of JCPyV-antiviral therapeutics.


Assuntos
Antivirais/química , Proteínas do Capsídeo/antagonistas & inibidores , Vírus JC/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/farmacologia , Internalização do Vírus/efeitos dos fármacos , Animais , Antivirais/síntese química , Sítios de Ligação , Bioensaio , Células COS , Proteínas do Capsídeo/química , Proteínas do Capsídeo/genética , Linhagem Celular Transformada , Chlorocebus aethiops , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Células HEK293 , Humanos , Vírus JC/crescimento & desenvolvimento , Vírus JC/metabolismo , Simulação de Acoplamento Molecular , Neuroglia/efeitos dos fármacos , Neuroglia/virologia , Ligação Proteica/efeitos dos fármacos , Multimerização Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Bibliotecas de Moléculas Pequenas/síntese química , Bibliotecas de Moléculas Pequenas/química
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