RESUMO
The aim of this study was the characterization of constitutive and induced defense mechanisms in the bark tissues of Cupressus sempervirens before and after infection with the bark fungus Seiridium cardinale, which is responsible for cypress canker disease. The time-course development of polyphenolic parenchyma (PP) cells and phloem axial resin duct (PARD)-like structures in the phloem was investigated in two C. sempervirens clones, one resistant and one susceptible to the disease, through anatomical and histological observations carried out by light microscope during a 19-day trial. PP cells were constitutively more abundant in the canker-resistant clone (R clone) compared with the susceptible clone (S clone), whereas PARD-like structures were not present in the bark of untreated plants of both clones. PP cells increased in both clones as a response to infection, but in the R clone, they were more abundant 5 and 12 days after inoculation. After inoculation, PARD-like structures appeared in the phloem after 5 days in the R clone and only after 12 days in the S clone. Even the number of cells surrounding the PARD-like structures was higher in the R clone 5 and 12 days after inoculation compared with the S clone. These observations demonstrate a faster phloem response of the R clone in the early phase of the infection. This may slow down initial growth of the fungus, contributing to the resistance mechanism.
Assuntos
Ascomicetos , Cupressus , Células Clonais , FloemaRESUMO
The study of the process of HIV entry into the host cell and the creation of biomimetic nanosystems that are able to selectively bind viral particles and proteins is a high priority research area for the development of novel diagnostic tools and treatment of HIV infection. Recently, we described multilayer nanoparticles (nanotraps) with heparin surface and cationic peptides comprising the N-terminal tail (Nt) and the second extracellular loop (ECL2) of CCR5 receptor, which could bind with high affinity some inflammatory chemokines, in particular, Rantes. Because of the similarity of the binding determinants in CCR5 structure, both for chemokines and gp120 HIV protein, here we expand this approach to the study of the interactions of these biomimetic nanosystems and their components with the peptide representing the V3 loop of the activated form of gp120. According to surface plasmon resonance results, a conformational rearrangement is involved in the process of V3 and CCR5 fragments binding. As in the case of Rantes, ECL2 peptide showed much higher affinity to V3 peptide than Nt (KD = 3.72 × 10-8 and 1.10 × 10-6 M, respectively). Heparin-covered nanoparticles bearing CCR5 peptides effectively bound V3 as well. The presence of both heparin and the peptides in the structure of the nanotraps was shown to be crucial for the interaction with the V3 loop. Thus, short cationic peptides ECL2 and Nt proved to be excellent candidates for the design of CCR5 receptor mimetics.
Assuntos
Proteína gp120 do Envelope de HIV/química , Proteína gp120 do Envelope de HIV/metabolismo , Modelos Moleculares , Receptores CCR5/química , Receptores CCR5/metabolismo , Humanos , Nanopartículas/química , Peptídeos/síntese química , Peptídeos/químicaRESUMO
A side effect of diabetes is formation of glycated proteins and, from them, production of advanced early glycation end products that could determine aberrant immune responses at the systemic level. We investigated a relevant aberrant post-translational modification (PTM) in diabetes based on synthetic peptides modified on the lysine side chain residues with 1-deoxyfructopyranosyl moiety as a possible modification related to glycation. The PTM peptides were used as molecular probes for detection of possible specific autoantibodies developed by diabetic patients. The PDC-E2(167-186) sequence from the pyruvate dehydrogenase complex was selected and tested as a candidate peptide for antibody detection. The structure-based designed type I' ß-turn CSF114 peptide was also used as a synthetic scaffold. Twenty-seven consecutive type 1 diabetic patients and 29 healthy controls were recruited for the study. In principle, the 'chemical reverse approach', based on the use of patient sera to screen the synthetic modified peptides, leads to the identification of specific probes able to characterize highly specific autoantibodies as disease biomarkers of autoimmune disorders. Quite surprisingly, both peptides modified with the (1-deoxyfructosyl)-lysine did not lead to significant results. Both IgG and IgM differences between the two populations were not significant. These data can be rationalized considering that i) IgGs in diabetic subjects exhibit a high degree of glycation, leading to decreased functionality; ii) IgGs in diabetic subjects exhibit a privileged response vs proteins containing advanced glycation products (e.g., methylglyoxal, glyoxal, glucosone, hydroimidazolone, dihydroxyimidazolidine) and only a minor one with respect to (1-deoxyfructosyl)-lysine.
Assuntos
Peptídeos/química , Peptídeos/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Produtos Finais de Glicação Avançada/metabolismo , Glicosilação , Glioxal/metabolismo , Humanos , Imidazóis/metabolismo , Imunoensaio , Cetoses/metabolismo , Lisina/química , Lisina/metabolismo , Processamento de Proteína Pós-Traducional , Aldeído Pirúvico/metabolismoRESUMO
Spartium junceum L. is a typical species of Mediterranean shrubland areas, also grown in gardens and parks as an ornamental. In recent years in Europe, S. junceum has been recurrently found to be infected by different subspecies and genotypes of the quarantine regulated bacterium Xylella fastidiosa (Xf). This work presents for the first time the anatomy of S. junceum plants that we found, by means of genetic and immunochemistry analysis, to be naturally infected by Xf subsp. multiplex ST87 (XfmST87) in Monte Argentario (Grosseto, Tuscany, Italy), a new outbreak area within the EU. Our anatomical observations showed that bacteria colonized exclusively the xylem conductive elements and moved horizontally to adjacent vessels through pits. Interestingly, a pink/violet matrix was observed with Toluidine blue staining in infected conduits indicating a high content of acidic polysaccharides. In particular, when this pink-staining matrix was observed, bacterial cells were either absent or degenerated, suggesting that the matrix was produced by the host plant as a defense response against bacterial spread. In addition, a blue-staining phenolic material was found in the vessels and, at high concentration, in the pits and inter-vessels. SEM micrographs confirmed that polysaccharide and phenolic components showed different structures, which appear to be related to two different morphologies: fibrillary and granular, respectively. Moreover, our LM observations revealed bacterial infection in xylem conductive elements of green shoots and leaves only, and not in those of other plant organs such as roots and flowers.
Assuntos
Spartium , Genótipo , Doenças das Plantas , Xylella , XilemaRESUMO
Within the Open Science project entitled 'Botanic Garden, factory of molecules', a multidisciplinary study approach was applied to Ballota acetabulosa (L.) Benth., at the Ghirardi Botanic Garden (Toscolano Maderno, BS, Italy). Micromorphological and histochemical investigations were performed on the secreting structures of the vegetative and reproductive organs under light, fuorescence and electronic microscopy. Concurrently the characterization of the volatiles spontaneously emitted from leaves and flowers were examined. Four trichome morphotypes were identified: peltate and short-stalked, medium-stalked and long-stalked capitate trichomes, each with a specific distribution pattern. The histochemical analysis was confirmed using ultrastructural observations, with the peltates and long-stalked capitates as the main sites responsible for terpene production. The head-space characterization revealed that sesquiterpene hydrocarbons dominated both in leaves and flowers, with γ-muurolene, ß-caryophyllene and (E)-nerolidol as the most abundant compounds. Moreover, a comparison with literature data concerning the ecological roles of the main compounds suggested their dominant roles in defence, both at the leaf and flower level. Hence, we correlated the trichome morphotypes with the production of secondary metabolites in an attempt to link these data to their potential ecological roles. Finally, we made the obtained scientific knowledge available to visitors of the Botanic Garden through the realization of new labelling dedicated to B. acetabulosa that highlights the 'invisible', microscopic features of the plant.
Assuntos
Ballota , Flores , Itália , Compostos Fitoquímicos , Folhas de Planta , TricomasRESUMO
Within an Open Science project, research was carried out to describe to the public of the Ghirardi Botanic Garden (BS, Lombardy, Italy) the invisible features of plants. This work is dedicated to Scutellaria altissima L. (Lamiaceae). Micromorphological, histochemical and phytochemical investigations were conducted on the vegetative and reproductive organs to correlate the structures involved in the emission of substances and their unique productivity. This work reports volatile organic compound (VOC) profiles of leaves and flowers and the composition of essential oil (EO) obtained from aerial parts of plants cultivated in Italy that have never been described before. Three morphotypes of glandular trichomes were observed: peltate, short-stalked capitate and long-stalked capitate. Peltate trichomes were the main producers of terpenes, short-stalked capitates of polysaccharides and long-stalked capitates of terpenes and polyphenols. The leaf VOC profile showed heterogeneous composition, with non-terpene derivatives as the major chemical class (71.04%), while monoterpene hydrocarbons represented almost the totality of the flower (99.73%). The leaf presented a higher number of total (37 versus 11) and exclusive (33 versus 7) compounds. (Z)-3-Hexenol acetate was most abundant in the leaf and (E)-ß-ocimene in the flower. Four common compounds were detected: ß-pinene, ß-caryophyllene, γ-muurolene and germacrene-D. The EO contaied 21 compounds, dominated by ß-caryophyllene, linalool and hexahydrofarnesyl acetone. This research allowed us to correlate morphotypes of the secretory structures with the production of secondary metabolites, with the aim of providing the public of the Ghirardi Botanic Garden with a dedicated iconographic approach, which accounts for olfactory perception linked to S. altissima.
Assuntos
Flores , Óleos Voláteis , Folhas de Planta , Scutellaria , Flores/anatomia & histologia , Flores/química , Jardins , Itália , Óleos Voláteis/química , Folhas de Planta/química , Scutellaria/química , Scutellaria/crescimento & desenvolvimento , Tricomas/anatomia & histologiaRESUMO
Members of the hominins - namely the so-called 'australopiths' and the species of the genus Homo - are known to possess short and deep mandibles and relatively small incisors and canines. It is commonly assumed that this suite of traits evolved in early members of the clade in response to changing environmental conditions and increased consumption of though food items. With the emergence of Homo, the functional meaning of mandible shape variation is thought to have been weakened by technological advancements and (later) by the control over fire. In contrast to this expectation, we found that mandible shape evolution in hominins is exceptionally rapid as compared to any other primate clade, and that the direction and rate of shape change (from the ape ancestor) are no different between the australopiths and Homo. We deem several factors including the loss of honing complex, canine reduction, and the acquisition of different diets may have concurred in producing such surprisingly high evolutionary rates. This study reveals the evolution of mandibular shape in hominins has strong morpho-functional and ecological significance attached.
Assuntos
Hominidae/anatomia & histologia , Hominidae/fisiologia , Mandíbula/anatomia & histologia , Animais , Evolução Biológica , Fósseis , Humanos , Mandíbula/patologiaRESUMO
For several years peptides have been used to investigate many aspects of the molecular mechanisms supporting the etiopathogenesis of neurological diseases. Even if well-established and commercially-available assays for the diagnosis of neurological diseases, based on peptides, are presently not available, much research has been focused to the comprehension of the pathogenetic mechanisms of relevant neurological diseases, such as Multiple Sclerosis, Alzheimer's disease and prion diseases. Several peptides, which strongly contributed to increase in the progress, and in the understanding of the molecular mechanisms of these important diseases, have been selected as antigens to be proposed in possible alternative diagnostic methodologies. The authors focused their attention on the possible peptides to be used as diagnostics for these three characteristic neurological diseases. In fact, Multiple Sclerosis is an autoimmune disease in which peptides have been used for the characterization of both B and T immune response, while Alzheimer's disease and prion diseases can be cumulative regarded as "protein folding disorders" in which peptides can be used to identify the misfolded protein.
Assuntos
Doenças do Sistema Nervoso/diagnóstico , Peptídeos , Doença de Alzheimer/diagnóstico , Peptídeos beta-Amiloides/sangue , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Animais , Autoanticorpos/líquido cefalorraquidiano , Linfócitos T CD4-Positivos/imunologia , Simulação por Computador , Humanos , Modelos Biológicos , Esclerose Múltipla/diagnóstico , Bainha de Mielina/imunologia , Fragmentos de Peptídeos/sangue , Fragmentos de Peptídeos/líquido cefalorraquidiano , Peptídeos/síntese química , Peptídeos/química , Doenças Priônicas/diagnóstico , Conformação ProteicaRESUMO
Myelin oligodendrocyte glycoprotein (MOG), a minor myelin component, is an important central nervous system specific target autoantigen for primary demyelination in autoimmune diseases such as multiple sclerosis (MS). The native structure of MOG presents a glycosylation site at position 31 (Asn(31)). It has been recently described that glycosylation of a MOG peptide epitope improved the detection of specific autoantibodies in sera of MS patients. The solution conformational behavior of two MOG derived peptides-hMOG(30-50) (1) and the glycosylated analogue [Asn(31)(N-beta-Glc)]hMOG(30-50) (2)-were investigated through NMR analysis in a water/HFA solution. Conformational studies revealed that peptides 1 and 2 adopted similar conformations in this environment. In particular, they showed strong propensity to assume a well-defined amphipatic structure encompassing residues 41-48. The N-terminal region resulted to be almost completely unstructured for both peptides. The presence in 1 of a low populated Asx-turn conformation characteristic of the Asn-Xaa-Thr glycosylation sites was the only conformational difference between peptides 1 and 2. Thus, the specific antibody recognition of peptide 2 is most likely driven by direct interactions of the antibody binding site with the Asn-linked sugar moiety.
Assuntos
Antígenos de Superfície/química , Autoanticorpos/análise , Autoantígenos/química , Esclerose Múltipla/imunologia , Glicoproteína Associada a Mielina/química , Oligodendroglia/química , Sequência de Aminoácidos , Epitopos , Glicosilação , Humanos , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Dados de Sequência Molecular , Proteínas da Mielina , Glicoproteína Mielina-Oligodendrócito , Conformação ProteicaRESUMO
We report for the first time the immunoadjuvant effects of lipoconjugation of peptide antigens in an in vitro system by using CD4+ T-cells. The lipopeptides obtained by conjugating a palmitoyl moiety at the N(alpha)-terminal of Gln(74) or at the epsilon-NH(2) of Lys(75) of GpMBP(74-85) induced increased T-cell responsiveness compared to the native nonlipidated peptide. On the other hand, lipoderivatives of GpMBP(82-98) did not increase the T-cell response, demonstrating that the superagonist inducing effect of lipoconjugation is epitope-specific. Digestion of the two native peptides with cathepsin D and L, both implicated in antigen processing, and with a complete lysosomal fraction of a EBV-transformed B cell line shows that GpMBP(74-85) is resistant to cellular proteases, while GpMBP(82-98) is easily digested by these enzymes. These results suggest that the first prerequisite for increasing the T-cell response by lipoconjugation is the stability of the native peptide to peptidases, providing an important insight into the understanding of the immunoadjuvant effect of lipoderivative antigens.
Assuntos
Linfócitos T CD4-Positivos/efeitos dos fármacos , Lipoproteínas/síntese química , Proteína Básica da Mielina/imunologia , Ácido Palmítico/química , Fragmentos de Peptídeos/imunologia , Peptídeo Hidrolases/química , Animais , Linfócitos T CD4-Positivos/imunologia , Catepsina D/química , Catepsina L , Catepsinas/química , Divisão Celular , Cisteína Endopeptidases , Epitopos , Feminino , Técnicas In Vitro , Lipoproteínas/química , Lipoproteínas/farmacologia , Lisossomos/enzimologia , Ratos , Ratos Endogâmicos Lew , Relação Estrutura-AtividadeRESUMO
Four previously reported kinin receptor peptide antagonists, including the B1 receptor-selective peptides desArg10-HOE 140 (H-D-Arg-Arg-Pro-Hyp-Gly-Thi-Ser-D-Tic-Oic-OH) and B-9858 (H-Lys-Lys-Arg-Pro-Hyp-Gly-Igl-Ser-D-Igl-Oic-OH), have been modified by replacement of the central tetrapeptide Pro-Hyp-Gly-Xaa with linear alkyl spacers of variable length. The analogue of desArg10-HOE 140 containing the 11-aminoundecanoic acid as spacer, MEN 11575 [H-D-Arg-Arg-NH-(CH2)10-CO-Ser-D-Tic-Oic-OH], was found to be slightly more potent than the unmodified peptide (pA2 = 7.1) as a kinin B1 receptor antagonist in the rat ileum longitudinal smooth muscle assay. Moreover, MEN 11575 is devoid of residual agonist activity at the kinin B1 receptor (rat ileum) and antagonist activity at the kinin B2 receptor (guinea pig ileum longitudinal smooth muscle). Both these activities are displayed by the parent peptide desArg10-HOE 140. Therefore, despite its greatly simplified chemical structure, MEN 11575 shows an improved pharmacological profile in terms of both potency and selectivity, and it represents a good template for the development of new peptidomimetic kinin B1 receptor antagonists. We also report an attempt to investigate the conformational role of the flexible, linear spacer of MEN 11575 and to design more constrained analogues, possibly locked in the bioactive conformation, using semirigid spacers based on Calpha-tetrasubstituted alpha-amino acids of the family of 1-aminocycloalkane-1-carboxylic acids (Acnc).
Assuntos
Oligopeptídeos/farmacologia , Peptídeos/farmacologia , Receptores da Neurocinina-3/antagonistas & inibidores , Sequência de Aminoácidos , Animais , Bradicinina/análogos & derivados , Bradicinina/química , Bradicinina/farmacologia , Cobaias , Técnicas In Vitro , Espectroscopia de Ressonância Magnética , Músculo Liso/efeitos dos fármacos , Oligopeptídeos/química , Peptídeos/química , RatosRESUMO
Galanin inhibited, in a concentration-dependent manner (EC50 7.2 nM), the positive inotropic response produced by field stimulation of isolated left atria from reserpine-pretreated guinea-pigs (in the presence of atropine). These responses were shown to involve antidromic activation of capsaicin-sensitive primary afferents. On the other hand, galanin did not affect the inotropic response to capsaicin or calcitonin gene-related peptide, the putative endogenous mediator released from sensory nerves. Galanin-(1-10) was at least 10,000 times less potent than the parent peptide, while galanin-(25-29) was ineffective. Likewise, galanin inhibited the non-cholinergic contraction produced by field stimulation of the isolated guinea-pig bronchus but not the contraction produced by exogenous neurokinin A. These findings indicate a prejunctional neuromodulatory action of galanin on the excitability of peripheral terminals of capsaicin-sensitive sensory nerves.
Assuntos
Capsaicina/farmacologia , Terminações Nervosas/efeitos dos fármacos , Neurônios Aferentes/efeitos dos fármacos , Peptídeos/farmacologia , Animais , Brônquios/efeitos dos fármacos , Peptídeo Relacionado com Gene de Calcitonina , Estimulação Elétrica , Galanina , Cobaias , Técnicas In Vitro , Masculino , Contração Muscular/efeitos dos fármacos , Neuropeptídeos/farmacologia , Tetrodotoxina/farmacologiaRESUMO
Spiro[androst-4-en-17 alpha,5'-oxazolidine]-2',3,4'-trione 8a and spiro[androst-4-en-17 alpha,5'-oxazolidine]-2',3,4',11-tetraone 8b, two potentially bioactive spiranes, were prepared from the parent 17-ketones in four steps (64% and 49.5% yield, respectively). The key intermediates were the hydroxyimidates 5a and 5b, which easily underwent cyclization to the corresponding spirooxazolinone 4'-enol ethers when treated with alkylchlorocarbonates. The respective N-amyl derivatives of the spiranes 8a and 8b were obtained with n-pentyl bromide in the presence of KF. A new method for the synthesis of steroid 17 alpha-hydroxy-17-carboxyesters and 17 alpha-hydroxy-17-carboxamides is described. Attempts to synthesize the title compounds from these products were unsuccessful.
Assuntos
17-Cetosteroides , Oxazóis/síntese química , Compostos de Espiro/síntese química , Esteroides/síntese química , Estrutura MolecularRESUMO
The crystal and molecular structures of the title compounds were determined by x-ray diffractometric analysis. Torsion angles and puckering parameters are reported for both compounds. In 1 the 5 alpha-cyano group influences the A-ring conformation. The carbonate ester 3 crystallizes in the monoclinic P2(1) space group with two molecules (I and II) in the asymmetric unit. The D-ring conformation is to some extent different between I and II.
Assuntos
Androstanos/química , Androstenos/química , Modelos Moleculares , Conformação Molecular , Estrutura Molecular , Difração de Raios XRESUMO
The authors report plasma substance P levels in obese children and healthy controls. Obese children showed significantly higher substance P values in comparison with controls. A positive correlation was found between substance P levels and percentage of weight increment.
Assuntos
Obesidade/sangue , Substância P/sangue , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , MasculinoRESUMO
A case of fetal duodenal atresia, dextrocardia and common atrioventricular canal diagnosed by ultrasound is described. The Authors emphasize the evaluation of right criteria for the a probable transfer of pregnant women to a qualified specialistic institute.
Assuntos
Anormalidades Múltiplas/diagnóstico , Dextrocardia/diagnóstico , Duodeno/anormalidades , Comunicação Atrioventricular/diagnóstico , Cardiopatias Congênitas/diagnóstico , Defeitos dos Septos Cardíacos/diagnóstico , Atresia Intestinal/diagnóstico , Adulto , Feminino , Humanos , Recém-Nascido , Gravidez , Resultado da Gravidez , Diagnóstico Pré-Natal , UltrassonografiaRESUMO
The Authors report a case of fetal ascites and hydrothorax with common atrioventricular canal diagnosed by ultrasound. They suspect a Down's syndrome confirmed by amniocentesis for fetal caryotype. They attach importance to the early diagnosis and to the cytogenetic research for therapeutic trend.
Assuntos
Anormalidades Múltiplas/genética , Síndrome de Down/complicações , Comunicação Atrioventricular/complicações , Hidropisia Fetal/complicações , Anormalidades Múltiplas/diagnóstico por imagem , Aborto Terapêutico , Adulto , Síndrome de Down/diagnóstico por imagem , Síndrome de Down/genética , Comunicação Atrioventricular/diagnóstico por imagem , Comunicação Atrioventricular/genética , Feminino , Humanos , Hidropisia Fetal/diagnóstico por imagem , Hidropisia Fetal/genética , Recém-Nascido , Gravidez , Segundo Trimestre da Gravidez , Ultrassonografia Pré-NatalRESUMO
The Authors report a case of right tubal abortion diagnosed by ultrasound in the sixth week of pregnancy. The operating report of pseudounicorn uterus showed a pregnancy in the tubal anlage of the atrophic hemicorn after external migration.
Assuntos
Aborto Espontâneo , Gravidez Tubária/complicações , Útero/anormalidades , Adulto , Feminino , Hemoperitônio/etiologia , Hemoperitônio/cirurgia , Humanos , Gravidez , Gravidez Tubária/diagnóstico por imagem , Gravidez Tubária/cirurgia , Ultrassonografia , Útero/cirurgiaRESUMO
The Authors describe a case of anencephaly diagnosed by ultrasound in the XV week of pregnancy. They confirm the importance of anamnesis to single out the persons at risk, but emphasize the validity of ultrasound for the chance diagnoses.
Assuntos
Anencefalia/diagnóstico por imagem , Feminino , Humanos , Gravidez , Segundo Trimestre da Gravidez , Diagnóstico Pré-Natal , UltrassonografiaRESUMO
The Authors report a very high frequency of premature births, of caesarean section and of complications in the puerperae as well as in the newborns found in 120 pregnant women with iron deficiency anemia in comparison with 120 healthy pregnant women. They confirm the importance of early diagnosis for prompt iron treatment.