Alessandra Pelagalli

Metal-ion catalyzed oxidation affects fibrinogen activity on platelet aggregation and adhesion.

Exposure of fibrinogen to the Fe3+/ascorbate oxidative system resulted in structural modifications and altered functionality of the glycoprotein. The overnight treatment of fibrinogen by oxidants caused a 20-fold increase of carbonyl content with respect to the native protein. Formation of dityrosines as well as loss of tryptophan following fibrinogen oxidation were observed. The occurrence of conformational changes of the fibrinogen molecule as a consequence of the oxidative treatment was also established. Oxidized fibrinogen showed a distinct capability from the native molecule to mediate platelet aggregation and adhesion. The percentage of ADP-induced platelet aggregation decreased as a function of fibrinogen oxidative damage. Further, both unstimulated platelets and ADP-activated platelets showed a reduced ability to adhere to oxidized fibrinogen than to the native protein. These results suggest that oxidative treatment alters fibrinogen domains involved in the recognition and the binding of this molecule by the platelet receptor GP IIb/IIIa.

THE MYCOTOXIN FUMONISIN B1 INHIBITS INTEGRIN-MEDIATED CELL-MATRIX ADHESION

Fumonisin B1 (FB1), a mycotoxin produced by the corn fungus Fusarium moniliforme, causes a variety of animal diseases and is a suspected human carcinogen. The FB1 molecule bears remarkable structural resemblance to the long-chain sphingoid base backbones of sphingolipids. The toxicity and carcinogenicity of FB1 has been ascribed to its ability to inhibit ceramide synthase, a key enzyme in the metabolism of complex sphingolipids. In this study we have investigated whether the exposure of B16-BL6 mouse melanoma cells to FB1 affects cell growth and integrin-mediated cell matrix adhesion. Cell treatment with the highest tested dose (75 microM) of FB1 for 72 h induced an about 20% inhibition of cell growth. FB1 strongly affected B16-BL6 cell adhesion to immobilized fibronectin, by causing a dose-dependent inhibition of cell attachment to this substrate. FB1 also inhibited in a dose-dependent manner the adhesion of B16-BL6 cells to the immobilized anti-fibronectin receptor antibody, whereas it affected only to a low extent cell attachment to concanavalin A. Our results demonstrate that FB1 treatment alters integrin adhesive activity, thus affecting all cellular integrin-dependent functions.

Aquaporins in Health and Disease: An Overview Focusing on the Gut of Different Species.

Aquaporins (AQPs) play a pivotal role in gut homeostasis since their distribution and function is modulated both in physiological and in pathophysiological conditions. The transport of water and solutes through gut epithelia is essential for osmoregulation and digestive and absorptive functions. This passage is regulated by different AQP isoforms and characterized by their peculiar distribution in the gastrointestinal tract. To date, AQP localization has been identified in the gut and associated organs of several mammalian species by different techniques (immunohistochemical, western blotting, and RT-PCR). The present review describes the modulation of AQP expression, distribution, and function in gut pathophysiology. At the same time, the comparative description of AQP in animal species sheds light on the full range of AQP functions and the screening of their activity as transport modulators, diagnostic biomarkers, and drug targets. Moreover, the phenotype of knockout mice for several AQPs and their compensatory role and the use of specific AQP inhibitors have been also reviewed. The reported data could be useful to design future research in both basic and clinical fields.

Tumor-educated mesenchymal stem cells promote pro-metastatic phenotype

Multipotent mesenchymal stem cells (MSCs) are recruited into tumor microenvironment in response to multiple signals produced by cancer cells. Molecules involved in their homing to tumors are the same inflammatory mediators produced by injured tissues: chemokines, cytokines and growth factors. When MSCs arrive into the tumor microenvironment these are “educated” to have pro-metastatic behaviour. Firstly, they promote cancer immunosuppression modulating both innate and adaptive immune systems. Moreover, tumor associated-MSCs trans-differentiating into cancer-associated fibroblasts can induce epithelial-mesenchymal-transition program in tumor cells. This process determinates a more aggressive phenotype of cancer cells by increasing their motility and invasiveness and favoring their dissemination to distant sites. In addition, MSCs are involved in the formation and modelling of pre-metastatic niches creating a supportive environment for colonization of circulating tumor cells. The development of novel therapeutic approaches targeting the different functions of MSCs in promoting tumor progression as well as the mechanisms underlying their activities could enhance the efficacy of conventional and immune anti-cancer therapies. Furthermore, many studies report the use of MSCs engineered to express different genes or as vehicle to specifically deliver novel drugs to tumors exploiting their strong tropism. Importantly, this approach can enhance local therapeutic efficacy and reduce the risk of systemic side effects.

Orexin and orexin receptor like peptides in the gastroenteric tract of Gallus domesticus: An immunohistochemical survey on presence and distribution.

This study reports the immunohistochemical localization and distribution of orexin A and B-like and their receptors-like peptides in the gastroenteric tract of chicken. The immunoreactivity is distributed in endocrine cells, nerve fibers and neurons, both in the stomach and intestine, and shows a discrete conformity with the data till now reported for Mammals. Our study suggests a possible participation of orexin-like peptides in the modulation of chicken gastroenteric activities and the preservation of their main distribution compared to Mammals. Western blot analysis has confirmed the presence of prepro-orexin and both receptors in the examined tissues. This survey represents the first evidence of the presence of orexin-like peptides in the gastroenteric tract of non mammalian species, and the results could help to better understand the alimentary control and body weight in domestic birds, which are of relevance to determine the productive factors in breeding animals. This study might also serve as a baseline for future experimental studies on the regulation of the gastroenteric functions in non mammalian Vertebrates.

Inhibition of AQP1 Hampers Osteosarcoma and Hepatocellular Carcinoma Progression Mediated by Bone Marrow-Derived Mesenchymal Stem Cells.

The complex cross-talk between tumor cells and their surrounding stromal environment plays a key role in the pathogenesis of cancer. Among several cell types that constitute the tumor stroma, bone marrow-derived mesenchymal stem cells (BM-MSCs) selectively migrate toward the tumor microenvironment and contribute to the active formation of tumor-associated stroma. Therefore, here we elucidate the involvement of BM-MSCs to promote osteosarcoma (OS) and hepatocellular carcinoma (HCC) cells migration and invasion and deepening the role of specific pathways. We analyzed the function of aquaporin 1 (AQP1), a water channel known to promote metastasis and neoangiogenes. AQP1 protein levels were analyzed in OS (U2OS) and HCC (SNU-398) cells exposed to conditioned medium from BM-MSCs. Tumor cell migration and invasion in response to BM-MSC conditioned medium were evaluated through a wound healing assay and Boyden chamber, respectively. The results showed that the AQP1 level was increased in both tumor cell lines after treatment with BM-MSC conditioned medium. Moreover, BM-MSCs-mediated tumor cell migration and invasion were hampered after treatment with AQP1 inhibitor. These data suggest that the recruitment of human BM-MSCs into the tumor microenvironment might cause OS and HCC cell migration and invasion through involvement of AQP1.

Expression and Localization of Aquaporin 4 and Aquaporin 5 along the Large Intestine of Colostrum‐Suckling Buffalo Calves

Aquaporins (AQPs) are membrane channel proteins that play a role in regulating water permeability in many tissues. To date, seven isoforms of AQPs have been reported in the gastrointestinal tract in different mammalian species. In contrast, both tissue distribution and expression of AQPs are unknown in the buffalo. The purpose of this study was to investigate the expression of both AQP4 and AQP5 mRNAs and their relative proteins in the large intestinal tracts of buffalo calves after colostrum suckling using reverse transcriptase polymerase chain reaction (RT‐PCR), Western blotting and immunohistochemistry. Our results revealed a diversified tissue AQP4 and AQP5 immunolocalization accompanied by their highest expression in the tissues of colostrum‐suckling buffalo calves confirmed by Western blotting. In particular, AQP4 was distributed along the endothelium and enterocytes while AQP5 in the endocrine cells. These findings provide direct evidence for AQP4 and AQP5 expression in the large intestine, suggesting that different AQPs collaborate functionally and distinctively in water handling during intestinal development, especially during the first period after delivery.

Orexins and receptor OX2R in the gastroenteric apparatus of two teleostean species: Dicentrarchus labrax and Carassius auratus.

Orexin A and B peptides and the receptor OX2R were studied in sea bass and goldfish gastroenteric tract by immunoblotting combined with densitometric analysis using NIH Image J software and immunohistochemical techniques. These teleost species present a different gut organization and diverse feeding habits. Immunoblotting experiments showed one band of 16 kDa corresponding to prepro‐orexin, and one band of 38 kDa corresponding to the OX2R receptor. Immunohistochemical localization of OXA and OXB was observed in the enteric nervous system throughout the gastroenteric tract of both species. OXA and OXB immunoreactive cells were found in the gastric and intestinal regions of sea bass, and were mainly found in the basal region of folds in intestinal bulb, and in the midgut and hindgut of goldfish. The distribution of OX2R was mainly detected in the mucosa of the gastroenteric tract of sea bass and goldfish. This distribution suggests an endocrine action of OXA and OXB in the gastrointestinal tract as well as involvement in the peripheral control of food intake and digestive processes in both species. This study might also serve to determine the productive factors in breeding and as a baseline for future experimental studies on the regulation of the gastroenteric functions in non‐mammalian vertebrates. Anat Rec, 299:1121–1129, 2016.

Structural and Functional Features of Choroid Epithelium from Buffalo Brain

Choroid plexuses (CPs) play pivotal roles in many processes that establish, survey, and maintain the biochemical and cellular status of the central nervous system (CNS). Changes in the anatomy and physiology of CPs have been linked to several CNS diseases. However, CP structure and function are not definitely known. Here, we report structural and functional features of choroid epithelium from buffalo brain never described before. Mixed with common epithelial cells, two novel cell types were identified by scanning and transmission electron microscopies. The first peculiar cells showed a globular apical portion projecting into the ventricular cavities, and a basal peduncle in direct contact with blood capillaries underlying the epithelium. The second type of cells resulted to be formed by a globular body from which depart numerous processes; these cells, localized deeply in the choroid epithelium, strictly contact neighboring epithelial cells. No synaptic contacts were detected between these cell populations and common epithelial cells. To gain some insight into the functional properties of choroid cells, NADPH diaphorase (NADPHd) and neuronal nitric oxide synthase (nNOS) activities were evaluated. Of interest, whereas a strong NADPHd activity was detected in all cell types of choroid epithelium, nNOS was only detected in the first type of peculiar cells. The presence of nNOS in the CPs was confirmed by Western blotting. These results suggest that nitric oxide may serve as a signal for the regulation of CP multiple functions. Anat Rec, 290:1399–1412, 2007.

F-18 FDG PET/CT metabolic tumor volume predicts overall survival in patients with disseminated epithelial ovarian cancer

OBJECTIVEnWe evaluated the prognostic impact of quantitative assessment by maximum standardized uptake value (SUVmax), metabolic tumour volume (MTV) and tumour lesion glycolysis (TLG) on [F-18] FDG PET/CT for patients with peritoneal carcinomatosis from epithelial ovarian cancer (EOC).nnnMETHODSnThirty-one patients with EOC underwent PET/CT for an early restaging after cytoreductive surgery, having been diagnosed with carcinomatosis (before chemotherapy). The SUVmax, MTV (cm3; 42% threshold) and TLG (g) were registered on residual peritoneal lesions. The patients were followed up 20±12months thereafter. The PET/CT results were compared to overall survival (OS).nnnRESULTSnThe Kaplan-Meier survival analysis for the SUVmax did not reveal significant differences in OS (p=0.48). The MTV survival analysis showed a significant higher OS in patients presenting with a higher tumour burden than those with less tumour burden (p=0.01; 26 vs. 14 months), whereas TLG exhibited a similar trend though not significant (p=0.06). Apart from chemo-resistance, the higher the MTV, the better will be the response to chemotherapy.nnnCONCLUSIONSnQuantitative assessment by MTV rather than by SUVmax and TLG on PET/CT may be helpful for stratifying patients who present with peritoneal carcinomatosis from EOC, in order to implement the appropriate therapeutic regimen.