Biomedical subjects

Carla Caruso

Publications and source records attributed to Carla Caruso.

9 recordsLinked to original sources

PubMed2006

Alpha-MSH and gamma-MSH modulate early release of hypothalamic PGE2 and NO induced by IL-1beta differently.

Interleukin-1beta (IL-1beta) stimulates corticotropin-releasing hormone (CRH) secretion in hypothalamus, which involves the release of prostaglandins (PGE2) and nitric oxide (NO). We have demonstrated that melanocortins can inhibit the early effects of IL-1beta on the HPA axis by acting on the central nervous system (CNS). Our study investigated whether alpha-melanocyte stimulating hormone (alpha-MSH) and gamma-MSH could inhibit IL-1beta-induced PGE2 and NO release in hypothalamus in the rapid activation of the HPA axis. An i.c.v. injection of 12.5 ng/microl of IL-1beta significantly increased the release of PGE2 and NOS activity in the hypothalamus. Treatment with alpha-MSH (0.1 microg/microl) inhibited the effect of IL-1beta on PGE2 release. Also, gamma-MSH (1 microg/microl) eliminated the increase in NOS activity induced by IL-1beta. Our data indicate the modulatory role of melanocortins in the early hypothalamic response to IL-1beta, with different regulation of PGE2 and NO release.

Animals↗

PubMed2006

Molecular and functional analysis of new members of the wheat PR4 gene family.

Five new genes belonging to the pathogenesis-related (PR) 4 family have been cloned and characterised in Triticum aestivum. Two full-length genes, named wPR4e and wPR4f-b, were isolated by library screening, demonstrating the presence of a small intron only in wPR4f-b. Two other PR4 genes (wPR4f-a and wPR4f-c) were isolated by PCR, showing very high sequence identity with wPR4f-b and constituting a new sub-family. Transcription start analysis was performed by RLM-RACE, leading to the isolation of a fifth gene, named wPR4g, that is highly homologous to wPR4e; both encode putative vacuolar PR4 proteins (Wheatwin7 and Wheatwin5, respectively). wPR4e and wPR4f sub-family genes are induced by F. culmorum infection, by chemicals that lead to systemic acquired resistance and by wounding, showing different spatial and temporal induction pathways. In silico analysis of the 5' untranslated regions of wPR4e and wPR4f-b revealed the presence of several abiotic and biotic stress-responsive elements. wPR4e and wPR4f-b putative promoters were fused to the beta-glucuronidase (GUS) reporter gene, and transient and stable expression assays demonstrated that both are able to drive expression of GUS. Characterisation of these new PR4 genes and particularly of their 5' untranslated regions, as well as the determination of their expression patterns, will contribute to our understanding of the responsiveness of this gene family to various stress conditions and of its role in plant defence.

Amino Acid Sequence↗

PubMed2005

NMDA and group I metabotropic glutamate receptors activation modulates substance P release from the arcuate nucleus and median eminence.

Glutamate participates in the regulation of secretion of several neuropeptides, including substance P (SP). Glutamate acts through ionotropic (iGluR) and metabotropic (mGluR) receptors. We have investigated whether glutamate receptor agonists and antagonists could affect SP release from the arcuate nucleus and the median eminence (ARC/ME). An increase in SP-like immunoreactivity (SP-LI) release from ARC/ME was induced by glutamate and N-methyl-D-aspartate (NMDA). This increase was prevented by D-(-)-2-amino-5-phosphono pentanoic acid (DAP5) (0.1mM), a specific NMDA antagonist and by (RS)-1-aminoindan-1,5-dicarboxylic acid (AIDA) (0.1 mM), a selective antagonist of group I mGluR. The selective non-NMDA receptor antagonist 6,7-dinitroquinoxaline-2,3(1H-4H)-dione (DNQX) (0.1mM) and (RS)-alpha-methyl-4-tetrazolylphenylglycine (MTPG) (0.1 mM), a group II and III mGluRs antagonist, did not affect the stimulatory effect of glutamate. A group I selective agonist, (S)-3,5-dihydroxyphenylglycine (DHPG) induced a significant increase in SP-LI release. Supporting the participation of nitric oxide (NO) in the effect of glutamate on SP-LI release, NAME (0.5 mM), a NO synthase inhibitor, reduced the glutamate-induced increase in SP-LI release from ARC/ME. Similarly, glutamate did not induce an increase in SP-LI release in the presence of meloxicam (0.1 mM) (a cyclooxygenase-2 (COX-2) specific inhibitor) indicating that prostaglandins production may also be involved in the glutamate effect. These data indicate that glutamate increases SP-LI release from the ARC/ME by acting through NMDA and group I mGluRs in the male rat. This stimulatory effect could be mediated by nitric oxide and prostaglandin production.

Animals↗

PubMed2005

CysMap and CysJoin: database and tools for protein disulphides localisation.

We have developed a computer program able to make user-customised databases derived from the public PIR non-redundant reference protein database. When the database of interest has been created, the user will generate the map of all the possible linear peptides containing one and two cysteines for each protein and combine them to calculate the mass of all the possible clusters of linear peptides linked by a disulphide bridge with a cysteine pair. It is also possible to create selected maps corresponding to peptides formed by the action of specific proteases. In this way, mass spectrometric data obtained from the hydrolysis of proteins of unknown sequence can be related to that contained in the database for quick disulphide assignment and protein identification. To confirm signal attribution, the program will also furnish the expected mass of cluster peptides after performing a cycle of Edman degradation. The utility of the program is discussed and examples of application are given.

Amino Acid Sequence↗

PubMed2004

Wheat pathogenesis-related proteins of class 4 have ribonuclease activity.

We have demonstrated that wheatwin1, a wheat pathogenesis-related protein of class 4 (PR4), has ribonuclease activity. Both native and recombinant proteins hydrolyse RNA from wheat coleoptils and have antifungal activity. Sepharose-bound wheatwin1 is able to interact with either wheat or Fusarium culmorum RNA. 3D modelling studies showed that, like ribonucleases A and T1, the action mechanism should involve two His residues, an Arg residue and an Asp residue.

Amino Acid Sequence↗

PubMed2004

Alpha-melanocyte-stimulating hormone through melanocortin-4 receptor inhibits nitric oxide synthase and cyclooxygenase expression in the hypothalamus of male rats.

There is evidence that alpha-melanocyte-stimulating hormone (alpha-MSH) has immunomodulatory and anti-inflammatory actions within the brain. In this study, we tested whether these actions are due to inhibition of the synthesis of nitric oxide (NO) and prostaglandins induced by lipopolysaccharide (LPS). Since melanocortin subtype MC4 receptor has been detected in the hypothalamus, we investigated the effect of central administration of alpha-MSH and HS024 (a selective MC4 receptor antagonist) on the gene expression of inducible, neuronal and endothelial NO synthase (iNOS, nNOS and eNOS) and on cyclooxygenase (COX-1 and COX-2) expression in the mediobasal hypothalamus (MBH) of LPS-treated male Wistar rats. Peripheral administration of LPS (250 microg/rat, 3 h) induced iNOS and COX-2 gene expression in the MBH. This stimulatory effect was reduced by alpha-MSH (3 nmol/rat) injected 30 min before LPS. alpha-MSH and HS024 (1 nmol/rat) alone had no effect on iNOS and COX-2 expression. The action of alpha-MSH on LPS-induced iNOS and COX-2 mRNA levels was not observed in the presence of HS024, suggesting that MC4-R may be involved in the modulatory effect of alpha-MSH. None of these treatments produced any modifications in nNOS, eNOS and COX-1 expression in MBH. The increase in serum corticosterone levels induced by LPS was attenuated by alpha-MSH. Both LPS and alpha-MSH decreased serum LH and prolactin levels. HS024 failed to modify the inhibitory effects of LPS and alpha-MSH on prolactin release but reverted the effect of LPS on LH secretion, indicating that MC4-R activation may be involved in the effects of alpha-MSH on LH secretion in male rats. When we examined the in vitro effect of LPS (10 microg/ml) and LPS plus interferon-gamma (IFN-gamma, 100 ng/ml) on iNOS expression in MBH, an increase in iNOS mRNA levels was observed only in the presence of LPS + IFN-gamma. This stimulatory effect was attenuated in the presence of alpha-MSH (5 microM), which by itself had no effect. No changes were found in nNOS, eNOS, COX-1 or COX-2 expression. These results indicate that alpha-MSH reduces the induction of iNOS and COX-2 gene expression at the hypothalamic level during endotoxemia and suggest that endogenous alpha-MSH may exert an inhibitory tone on iNOS and COX-2 transcription via MC4 receptors acting as a local anti-inflammatory agent within the hypothalamus.

Animals↗

PubMed2004

Structural properties of the protein SV-IV.

We have investigated the molecular mechanisms that produce different structural and functional behavior in the monomeric and trimeric forms of seminal vesicle protein no. 4, a protein with immunomodulatory, anti-inflammatory, and procoagulant activity secreted from the rat seminal vesicle epithelium. The monomeric and trimeric forms were characterized in solution by CD. Details of the self-association process and structural changes that accompany aggregation were investigated by different experimental approaches: trypsin proteolysis, sequence analysis, chemical modification, and computer modeling. The self-association process induces conformational change mainly in the 1-70 region, which appears to be without secondary structure in the monomer but contains alpha-helix in the trimer. In vivo, proteolysis of seminal vesicle protein no. 4 generates active peptides and this is affected by the monomer/trimer state, which is regulated by the concentration of the protein. The information obtained shows how conformational changes between the monomeric and trimeric forms represent a crucial aspect of activity modulation.

Animals↗

PubMed2003

Comparing the modeled structures of PR-4 proteins from wheat.

We have constructed three-dimensional models of four pathogenesis-related (PR) proteins from wheat (wheatwins) belonging to the PR-4 family. All the models were based on the knowledge of the tertiary structure of barwin, a highly homologous protein from barley. Wheatwin1 and wheatwin2 differ in two amino acid residues (positions 62 and 68) out of 125. Wheatwin4 differs from wheatwin2 in one residue at position 78, while wheatwin3 differs from wheatwin1 in one residue at position 88. The global folding and the secondary structures were very similar through all the sequences, including the regions of the amino acid substitutions. The main differences were found in the traits 15-21, 84-86 and 91-93. Trait 15-21 was predicted as ss-sheet in wheatwin4 and random-coil in the other proteins. Trait 84-86 was predicted as ss-sheet in wheatwin3 and random-coil in the other proteins. Trait 91-93 was predicted as random coil in wheatwin1 and wheatwin3 and ss-sheet in the other two proteins. Traits 15-21 and 84-86 were exposed, while trait 91-93 was quite hidden in all the proteins. The antifungal activities of the four proteins towards the specific pathogenic fungus Fusarium culmorum were distinct and well correlated to the structural differences. These results suggest that these regions may have a role in the action mechanism, which is still unknown.

Amino Acid Sequence↗

PubMed2002

Lipopolysaccharide- and tumor necrosis factor-alpha-induced changes in prolactin secretion and dopaminergic activity in the hypothalamic-pituitary axis.

Bacterial lipopolysaccharide (LPS) affects pituitary hormone secretion, including prolactin release, by inducing synthesis and release of cytokines such as tumor necrosis factor-alpha (TNF-alpha). Since prolactin is mainly under tonic inhibitory control of dopamine, we investigated the effect of LPS and TNF-alpha on the hypothalamic-pituitary dopaminergic system. LPS (100-250 microg/rat, i.p.) decreased serum prolactin levels after 1 or 3 h. Sulpiride, a dopaminergic antagonist, increased serum prolactin and blocked the inhibitory effect of LPS. LPS increased hypothalamic dopamine and DOPAC concentrations and the DOPAC/dopamine ratio both in mediobasal hypothalamus and the posterior pituitary. LPS also enhanced dopamine and DOPAC concentration in the anterior pituitary. LPS elevated plasma levels of epinephrine, norepinephrine and dopamine but it did not modify the concentration of epinephrine or norepinephrine in the tissues studied. The administration of TNF-alpha (i.c.v., 1 h, 100 ng/rat) decreased serum prolactin but did not affect plasma catecholamine levels. TNF-alpha did not modify the DOPAC/dopamine ratio in hypothalamus or posterior pituitary but increased dopamine and DOPAC concentrations in the anterior pituitary. Incubations of hypothalamic explants showed that TNF-alpha did not modify in vitro basal dopamine release and reduced K(+)-evoked dopamine release. On the contrary, incubations of posterior pituitaries showed that TNF-alpha significantly increased basal and K(+)-evoked dopamine release. These results indicate that LPS and TNF-alpha increase dopamine turnover in the hypothalamic-pituitary axis. This increase in dopaminergic activity could mediate the inhibitory effect of LPS and TNF-alpha on prolactin release. Furthermore, the increase in dopaminergic activity elicited by LPS could be mediated by an increase in hypothalamic TNF-alpha during endotoxemia.

3,4-Dihydroxyphenylacetic Acid↗