Francesco Maione

Reduced inflammatory and neuropathic pain and decreased spinal microglial response in fractalkine receptor (CX3CR1) knockout mice

J. Neurochem. (2010) 114, 1143–1157.

New insights of dimethyl sulphoxide effects (DMSO) on experimental in vivo models of nociception and inflammation.

DMSO is one of the most common solvents used experimentally to dissolve hydrophobic substances for in vivo and in vitro purposes. A wide range of pharmacological effects exerted by DMSO has been documented in both animal and human experimental models. However, only a few and sometimes contrasting data about the effects of DMSO in animal models of nociception and inflammation are presently available. In this study, we evaluated the effects induced by DMSO and a DMSO-containing saline on thermal and chemical nociception, inflammation and locomotor activity in CD1 mice. We demonstrated that centrally or orally administered DMSO displayed anti-nociceptive effects to thermal (hot plate and tail-flick test) and chemical (formalin test) stimuli. Conversely, DMSO was able to increase both nociceptive phases in the formalin test when applied subcutaneously in the dorsal surface of the mouse hind paws 10 min before formalin administration. Oral administration of DMSO produced anti-inflammatory effects on zymosan-induced edema in the mouse paw, whereas local administration potentiated the inflammatory action exerted by zymosan. Oral and central, but not local, administration of DMSO improved the mouse locomotor activity. These results suggest that DMSO displayed opposite effects on nociception and inflammation, depending on the route of administration. New and helpful evidence about DMSO laboratory applications need to be considered in the in vivo studies to assess correctly the pharmacological properties of investigated drugs.

Design and characterization of a cleavage-resistant Annexin A1 mutant to control inflammation in the microvasculature

Human polymorphonuclear leukocytes adhesion to endothelial cells during the early stage of inflammation leads to cell surface externalization of Annexin A1 (AnxA1), an effector of endogenous anti-inflammation. The antiadhesive properties of AnxA1 become operative to finely tune polymorphonuclear leukocytes transmigration to the site of inflammation. Membrane bound proteinase 3 (PR3) plays a key role in this microenvironment by cleaving the N terminus bioactive domain of AnxA1. In the present study, we generated a PR3-resistant human recombinant AnxA1-named superAnxA1 (SAnxA1)-and tested its in vitro and in vivo properties in comparison to the parental protein. SAnxA1 bound and activated formyl peptide receptor 2 in a similar way as the parental protein, while showing a resistance to cleavage by recombinant PR3. SAnxA1 retained anti-inflammatory activities in the murine inflamed microcirculation (leukocyte adhesion being the readout) and in skin trafficking model. When longer-lasting models of inflammation were applied, SAnxA1 displayed stronger anti-inflammatory effect over time compared with the parental protein. Together these results indicate that AnxA1 cleavage is an important process during neutrophilic inflammation and that controlling the balance between AnxA1/PR3 activities might represent a promising avenue for the discovery of novel therapeutic approaches.

In vivo characterisation of superficial colorectal neoplastic lesions with high-resolution probe-based confocal laser endomicroscopy in combination with video-mosaicing: A feasibility study to enhance routine endoscopy

BACKGROUND Recent technological advances in miniaturisation have allowed for a confocal scanning microscope to be integrated into trans-endoscopic probes enabling endoscopists to collect in vivo virtual biopsies of the gastrointestinal mucosa during endoscopy. AIMS The aim of the present study was to assess prospectively the clinical applicability and predictive power of a probe-based confocal laser endomicroscopy for the in vivo diagnosis of colorectal neoplasia. METHODS Patients with evidence of colorectal superficial neoplasia at routine endoscopy, were included prospectively in this study. Lesions were identified using white-light endoscopy followed by pCLE imaging recorded by a Coloflex UHD-type probe. The images were interpreted as either neoplastic or not according to vascular and cellular changes. pCLE readings were then compared with histopathological results from endoscopically resected lesions and/or targeted biopsy specimens. RESULTS A total of 32 lesions were identified in 20 consecutive patients. Histopathology diagnosis was of adenomas in 19 cases, hyperplastic polyps in 11 cases and adenocarcinoma in 2 cases. For the detection of neoplastic tissue pCLE had a sensitivity of 100%, a specificity of 84.6%, an accuracy of 92.3, a PPV of 90.5% and a NPV of 100%. CONCLUSIONS pCLE permits high-quality imaging, enabling prediction of intraepithelial neoplasia with a high level of accuracy.

Interleukin 17 sustains rather than induces inflammation.

Interleukin (IL)17 is a novel cytokine that has been suggested to play a key role in sustaining chronic inflammation in autoimmune diseases. Since its discovery, much attention has been given to mediators and factors responsible for the development of IL-17-producing cells while very few studies have investigated the inflammatory properties of this cytokine. Here we aimed to characterize the inflammatory properties of IL-17 and to establish if this cytokine per se can initiate an inflammatory reaction or if its main role is to contribute to the exacerbation of ongoing inflammation. To this aim we used two different mouse models of inflammation: the paw oedema and the airpouch. Interestingly, injection of IL-17 in the hind paw did not cause oedema while administration in the pre-inflamed tissues of 6-day-old air pouches induced a long lasting inflammatory reaction that was sustained between 4 and 24h post-injection. Phenotypic analysis of cellular infiltrates demonstrated selective PMN recruitment in exudates and pouch lining tissues. This event was accompanied by induction of a distinct set of pro-inflammatory cytokines including IL-1beta, IL-6, TNF-alpha and chemokines KC and MCP-1. Co-administration of a neutralizing anti-KC antibody with IL-17 significantly reduced its inflammatory response suggesting a key role for this chemokine in mediating the inflammatory effects of IL-17. In conclusion these results demonstrate that IL-17 does not initiate an inflammatory reaction while, if injected in pre-inflamed tissues, is able to further amplify biochemical and cellular events characteristic of the early stages of the inflammatory reaction.

Modulation of experimental autoimmune encephalomyelitis by endogenous Annexin A1

BackgroundAutoimmune diseases, like multiple sclerosis, are triggered by uncontrolled activation of cells of the immune system against self-antigen present, for instance, in the central nervous system. We have reported novel biological functions for Annexin A1, an effector of endogenous anti-inflammation, to produce positive actions on the adaptive immune system by reducing the threshold of T cell activation. In this study, we investigated the potential modulatory role of Annexin A1 in the development of experimental autoimmune encephalomyelitis, a model of multiple sclerosis.MethodsMale control C57/BL6 and AnxA1 null mice were immunized subcutaneously with an emulsion consisting of 300 μg of MOG35-55 in PBS combined with an equal volume of CFA. Lymph node cells obtained from mice immunized with MOG33-55 for 14 days were re-stimulated in vitro with MOG33-55 (100 μg/ml) for 4 days and the Th1/Th17 cytokine profile measured by ELISA. Spinal cords were processed either to isolate the infiltrated T cells or fixed and stained with haematoxylin and eosin. Statistical analyses were performed using two-tailed, unpaired Students t tests or ANOVA.ResultsOur results show a direct correlation between Annexin A1 expression and severity of EAE. Analysis of MOG35-55-induced EAE development in Annexin A1 null mice showed decreased signs of the disease compared to wild type mice. This defect was significant at the peak of the disease and accompanied by reduced infiltration of T cells in the spinal cord. Finally, analysis of the T cell recall response in vitro following stimulation with MOG35-55 showed a decrease proliferation of Annexin A1 null T cells, with a significantly reduced Th1/Th17 phenotype, compared to wild type cells.ConclusionTogether these findings suggest that Annexin A1 null mice have an impaired capacity to develop EAE. Furthermore strategies aiming at reducing Annexin A1 functions or expression in T cells might represent a novel therapeutic approach for multiple sclerosis.

Peptide-modified liposomes for selective targeting of bombesin receptors overexpressed by cancer cells: a potential theranostic agent

Objectives Drug delivery systems consisting of liposomes displaying a cell surface receptor-targeting peptide are being developed to specifically deliver chemotherapeutic drugs to tumors overexpressing a target receptor. This study addresses novel liposome composition approaches to specifically target tissues overexpressing bombesin (BN) receptors. Methods A new amphiphilic peptide derivative (MonY-BN) containing the BN(7–14) peptide, the DTPA (diethylenetriaminepentaacetate) chelating agent, a hydrophobic moiety with two C18 alkyl chains, and polyethylene glycol spacers, has been synthesized by solid-phase methods. Liposomes have been generated by co-aggregation of MonY-BN with 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC). The structural and biological properties of these new target-selective drug-delivery systems have been characterized. Results Liposomes with a DSPC/MonY-BN (97/3 molar ratio) composition showed a diameter of 145.5 ± 31.5 nm and a polydispersity index of 0.20 ± 0.05. High doxorubicin (Dox) loading was obtained with the remote pH gradient method using citrate as the inner buffer. Specific binding to PC-3 cells of DSPC/MonY-BN liposomes was obtained (2.7% ± 0.3%, at 37°C), compared with peptide-free DSPC liposomes (1.4% ± 0.2% at 37°C). Incubation of cells with DSPC/ MonY-BN/Dox showed significantly lower cell survival compared with DSPC/Dox-treated cells, in the presence of 100 ng/mL and 300 ng/mL drug amounts, in cytotoxicity experiments. Intravenous treatment of PC-3 xenograft-bearing mice with DSPC/MonY-BN/Dox at 10 mg/kg Dox dose produced higher tumour growth inhibition (60%) compared with nonspecific DSPC/ Dox liposomes (36%) relative to control animals. Conclusion The structural and loading properties of DSPC/MonY-BN liposomes along with the observed in-vitro and in-vivo activity are encouraging for further development of this approach for target-specific cancer chemotherapy.

Diagnostic accuracy of confocal laser endomicroscopy in diagnosing dysplasia in patients affected by long-standing ulcerative colitis

AIM To evaluate the diagnostic accuracy of confocal laser endomicroscopy (CLE) for the detection of dysplasia in long-standing ulcerative colitis (UC). METHODS We prospectively performed a surveillance colonoscopy in 51 patients affected by long-standing UC. Also, in the presence of macroscopic areas with suspected dysplasia, both targeted contrasted indigo carmine endoscopic assessment and probe-based CLE were performed. Colic mucosal biopsies and histology, utilised as the gold standard, were assessed randomly and on visible lesions, in accordance with current guidelines. RESULTS Fourteen of the 51 patients (27%) showed macroscopic mucosal alterations with the suspected presence of dysplasia, needing chromoendoscopic and CLE evaluation. In 5 macroscopically suspected cases, the presence of dysplasia was confirmed by histology (3 flat dysplasia; 2 DALMs). No dysplasia/cancer was found on any of the outstanding random biopsies. The diagnostic accuracy of CLE for the detection of dysplasia compared to standard histology was sensitivity 100%, specificity 90%, positive predictive value 83% and negative predictive value 100%. CONCLUSION CLE is an accurate tool for the detection of dysplasia in long-standing UC and shows optimal values of sensitivity and negative predictivity. The scheduled combined application of chromoendoscopy and CLE could maximize the endoscopic diagnostic accuracy for diagnosis of dysplasia in UC patients, thus limiting the need for biopsies.

Suppression of inflammatory response by chrysin, a flavone isolated from Potentilla evestita Th. Wolf. In silico predictive study on its mechanistic effect

Flavonoids are the most abundant natural polyphenols widely distributed in plants. Among them, chrysin has recently attracted the attention for its anti-tumor and anti-oxidant activities and also for its protective effects on allergic inflammation. Therefore, in this study, we set out to investigate and characterize the effects of chrysin in classical models of inflammation reasoning that this would expand our knowledge on the pharmacological properties of this flavone. To this aim we have firstly isolated chrysin from Potentilla evestita Th. Wolf. and successively evaluated its anti-inflammatory and analgesic potential on writhing and formalin test and also on carrageenan-induced paw oedema. Finally, the present study was planned to investigate, by the aim of docking analysis, the molecular interaction of this compound on the binding site of COX-1 and COX-2 enzymes. On writhing test, we observed a significant inhibition of writhings after the administration of chrysin at 5.0 and 10.0 mg/kg i.p. (25.00±9.22% and 55.67±7.62% respectively). On formalin test, the flavone at dose of 10.0 mg/kg i.p. displayed its maximum analgesic and anti-inflammatory effect on both early (35.67±7.88%) and late phase (50.57±5.36%) and similarly displayed at 4h a significant anti-inflammatory effect in carrageenan-induced paw oedema. Moreover, in silico analysis of receptor ligand complex shows that chrysin interacts weakly with COX-1 binding site whereas displayed a remarkable interaction with COX-2. These findings suggest that the flavone chrysin isolated from P. evestita Th. Wolf. possesses in vivo anti-inflammatory and anti-nociceptive potential, which are supported in silico by an interaction with COX-2 binding site.

Molecular mechanism of tanshinone IIA and cryptotanshinone in platelet anti-aggregating effects: an integrated study of pharmacology and computational analysis.

Tanshinone IIA and cryptotanshinone are two pharmacologically active diterpenoids extracted from the roots of Salvia milthiorriza Bunge, a plant used in Chinese traditional medicine for the treatment of some cardiovascular and cerebrovascular disease. Until now, the molecular mechanisms of action of these two diterpenoids on platelets are partially known. To clarify this aspect, here we utilized an integrated study of pharmacology and computational analysis. Our results demonstrate that cryptotanshinone is able to inhibit in a concentration dependent manner the rat platelet aggregation and also is endowed of Gi-coupled P2Y12 receptor antagonist as demonstrated by docking studies. This computational method was also performed for tanshinone IIA demonstrating even for this diterpenoid an interaction with the same receptor. The findings from our study enable a better understanding of tanshinone IIA and cryptotanshinone biological properties, which could ultimately lead to the development of novel pharmaceutical strategies for the treatment and/or prevention of some cardiovascular disease.