Stereodivergent Synthesis of 5-Aminopipecolic Acids and Application in the Preparation of a Cyclic RGD Peptidomimetic as a nanomolar αVβ3 Integrin Ligand

A stereodivergent strategy was devised to obtain enantiopure cis and trans 5-aminopipecolic acids (5-APAs) in suitably protected forms to be employed in peptide synthesis as conformationally constrained \u3b1- and \u3b4-amino acids. The cis isomer was used as a \u3b4-amino acid to construct a cyclic RGD-containing peptidomimetic, the ability of which to compete with biotinylated vitronectin for the binding to the isolated \u3b1V\u3b23 integrin was measured (IC50 = 4.2 \ub1 0.9 nM). A complete 1H NMR and computational conformational analysis was performed to elucidate the reasons for the high affinity of this cyclic peptidomimetic in comparison with Cilengitide

Proteomic analysis of saliva: a unique tool to distinguish primary Sjogren's syndrome from secondary Sjogren's syndrome and other sicca syndromes

Introduction: A growing interest has arisen in salivary proteomics as a tool for the identification of biomarkers for primary Sjogren's syndrome (pSS). Nonetheless, only a limited number of preclinical validation studies have been performed, limiting the possibility of translating proteomic results into clinical practice. The primary aim of this study was to refine the diagnostic power of a panel of candidate salivary biomarkers described in pSS with respect to both healthy volunteers and pathological controls. We also explored the pathogenetic function of the detected putative biomarkers both in the local exocrinopathy and in the systemic inflammatory processes of SS. Methods: One hundred and eighty patients were included in the study overall. In the first "exploratory phase", we enrolled 40 females with pSS, 40 sex-and age-matched healthy volunteers, 10 patients with sicca non-SS and 15 secondary SS (sSS) patients. The testing cohort of the second "challenge phase" of the study was represented by 75 unselected, consecutive subjects: 19 pSS, 21 healthy volunteers, 10 sicca non-SS and 25 sSS patients. Salivary proteomic analysis was performed combining two-dimensional electrophoresis (2DE) and matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF-MS). Western blot (WB) analysis and enzyme-linked immunosorbent assay (ELISA) were employed to validate 2DE results. Ingenuity Pathway Analysis (IPA) Knowledge base was adopted to associate candidate biomarkers in a signalling pathogenetic network. Results: A total of 28, 6, 7 and 12 protein spots were found to be significantly different in pSS samples with respect to healthy volunteers, non-SS sicca syndrome, SSc-sSS and rheumatoid arthritis-sSS, leading to the identification of 15 differently expressed proteins. Among them, alpha-amylases precursor, carbonic anhydrase VI, beta-2 microglobulin, glyceraldehydes-3-phosphate dehydrogenase (G3PDH), epidermal fatty acid binding protein (E-FABP) and immunoglobulin k light chain (IGK-light chain) apparently showed the most significant differences in pSS when compared to healthy volunteers and non-SS pathological controls. On the other hand, as expected, pSS and sSS salivary profiles shared a great number of similarities. Conclusions: This study demonstrated that salivary fluid might represent a novel ideal milieu for the detection of a diagnostic panel of candidate biomarkers for pSS, and to gain an insight into the pathogenetic processes underlying glandular and systemic autoimmune disorders

Synthesis and conformational analysis of peptides embodying 2,3-methanopipecolic acids

The conformational analysis of linear and cyclic peptides incorporating 2,3-methanopipecolic acids (or Cyclopropane Pipecolic Acids, CPAs) as conformationally constrained \u3b1-amino acids is reported. Compared to peptides containing proline or pipecolic acid, a striking increase of the cis isomer (42\u201392%) around the CPA amide bond is observed, both in water and organic solvents, when these unnatural amino acids are embodied in linear amino acid sequences. The rotational barrier around the same bond in water was calculated, giving results comparable to that for the prolyl cis/trans isomerization. In organic solvents, CPAs at the i + 2 position of a peptide induce the formation of a type VIa \u3b2-turn secondary structure. When incorporated into a cyclic peptide, the cis geometry around the 2,3-methanopipecolic amide bond still prevails and, in the example studied herein (a cyclic RGD-containing ligand of \u3b1V\u3b23 integrin mimicking Cilengitide), conservation of the backbone geometry and side chain spatial orientation of the native peptide is also found. Given the importance of the proline cis/trans isomerism in many biological processes, CPAs could be useful as proline mimetics for probing protein\u2013ligand interactions and generating novel bioactive compounds

fibromyalgia and sexual problems

The aim of this review was to describe the recent literature concerning sexual dysfunction in fibromyalgic patients. To this end, we used the common online databases PubMed, MEDLINE and EMBASE (up to June 2012) and searched for the key words fibromyalgia (FM) and sexual dysfunction. All the studies examined underlined that FM is strictly associated with sexual dysfunction in women. The major findings observed were related to a decreased sexual desire and arousal, decreased experience of orgasm, and in some studies an increase in genital pain. The psychological aspects, together with the stress related to the constant presence of chronic widespread pain, fatigue and sleep disturbances, are certainly a major factor that adversely affects the sexuality of the patient with FM. Moreover, the drugs most commonly used in these cases may interfere negatively on the sexuality and sexual function of these patients. Therefore, the therapeutic intervention should be targeted and the side effects should be weighed up against the positive effects. It is of the utmost importance to recognise the problem of sexuality and sexual dysfunction in a more complex form of its expression and undertake a multidisciplinary therapeutic intervention to improve the quality of FM patients' life

[MALDI-TOF and SELDI-TOF analysis: "tandem" techniques to identify potential biomarker in fibromyalgia].

Fibromyalgia (FM) is characterized by the presence of chronic widespread pain throughout the musculoskeletal system and diffuse tenderness. Unfortunately, no laboratory tests have been appropriately validated for FM and correlated with the subsets and activity. The aim of this study was to apply a proteomic technique in saliva of FM patients: the Surface Enhance Laser Desorption/Ionization Time-of-Flight (SELDI-TOF). For this study, 57 FM patients and 35 HC patients were enrolled. The proteomic analysis of saliva was carried out using SELDI-TOF. The analysis was performed using different chip arrays with different characteristics of binding. The statistical analysis was performed using cluster analysis and the difference between two groups was underlined using Student's t-test. Spectra analysis highlighted the presence of several peaks differently expressed in FM patients compared with controls. The preliminary results obtained by SELDI-TOF analysis were compared with those obtained in our previous study performed on whole saliva of FM patients by using electrophoresis. The m/z of two peaks, increased in FM patients, seem to overlap well with the molecular weight of calgranulin A and C and Rho GDP-dissociation inhibitor 2, which we had found up-regulated in our previous study. These preliminary results showed the possibility of identifying potential salivary biomarker through salivary proteomic analysis with MALDI-TOF and SELDI-TOF in FM patients. The peaks observed allow us to focus on some of the particular pathogenic aspects of FM, the oxidative stress which contradistinguishes this condition, the involvement of proteins related to the cytoskeletal arrangements, and central sensibilization