Galectins: major signaling modulators inside and outside the cell.

Galectins control cell behavior by acting on different signaling pathways. Most of the biological activities ascribed to these molecules rely upon recognition of extracellular glycoconjugates and establishment of multivalente interactions, which trigger adaptive biological responses. However, galectins are also detected within the cell in different compartments, where their regulatory functions still remain poorly understood. A deeper understanding of the entire galectin signalosome and its impact in cell behavior is therefore essential in order to delineate new strategies to specifically manipulate both galectin expression and function. This review summarizes our current knowledge of the signaling pathways activated by galectins, their glycan dependence and the cellular compartment where they become activated and are biologically relevant.

Risk of permanent stoma in extensive Crohn's colitis: the impact of biological drugs.

AIM: The overall risk of permanent stoma was determined in patients with extensive Crohn's colitis. An attempt was made to analyse whether biological drugs have modified the surgical approach in patients with anorectal involvement. METHOD: In all, 233 patients with Crohn's disease colitis operated on between 1995 and 2010 were reviewed retrospectively. Fifty-one were treated before 2002 (prebiological era) and 182 after 2002 (biological era). The relationship was determined between the use of immunosuppressors, biological drugs, the presence of perianal disease and anorectal stenosis and the rate of permanent stoma formation. RESULTS: In the prebiological era 23 (45.1%) patients without anorectal involvement underwent colectomy and ileorectal anastomosis, 17 (33.3%) with severe anorectal disease had proctocolectomy and 11 (21.6%) with anorectal involvement had abdominal colectomy with permanent ileostomy. In the biological era 73 (40.1%) patients without anorectal involvement underwent colectomy and ileorectal anastomosis, nine (5%) with severe anorectal involvement had proctocolectomy and 100 (54.9%) with anorectal involvement had colectomy with terminal ileostomy. Of these 100, 75 have subsequently been treated with biological drugs with full regression of anorectal lesions in 81.3%. Rates of permanent stoma in the prebiological and biological era were 60.8% and 19.2% (P < 0.001). Univariate and multivariate analysis showed that only the use of biological drugs was significantly associated with an increased rate of rectal preservation (P < 0.05). CONCLUSION: The risk of a permanent stoma in patients with Crohn's colitis and anorectal involvement is significantly reduced with combined surgical and biological treatment.

Obstructive sleep apnoea is improved by a prolonged treatment of gastrooesophageal reflux with omeprazole.

BACKGROUND: Obstructive sleep apnoea has been demonstrated to induce gastrooesophageal reflux through highly negative intrathoracic pressure during the attacks. However, we believe that gastrooesophageal reflux on its part may favour or aggravate the apnoea attacks. AIMS: We investigated whether the treatment of gastrooesophageal reflux with omeprazole is able to decrease apnoea attacks. PATIENTS AND METHODS: Twenty patients (mean age 55.4 years, range 49-73 years; 17 males) with confirmed obstructive sleep apnoea at overnight polysomnography and pathological gastrooesophageal reflux at ambulatory 24-h oesophageal pHmetry were asked to note in a diary the occurrence of apnoea attacks for a basal period of 4 weeks. Subsequently, the patients were randomly and in a double-blind manner treated with omeprazole 20mg (10 patients, group A) or placebo (10 patients, group B) by giving 1 cp 30 min before breakfast and 1 cp 30 min before dinner for another 6 weeks with a diary documentation. The results were averaged weekly and over the entire treatment duration and a statistical comparison was made between the groups and within each group before and after treatment. RESULTS: The mean weekly frequency of apnoea attacks of group A during the entire period of treatment with omeprazole was significantly decreased with respect to the basal period and was significantly lower than that of group B. The weekly frequency of apnoea attacks in group A started to be significantly lower from the third week than the corresponding values of both group B and the basal period, reaching a decrease of about 73% in the sixth week. CONCLUSION: The occurrence of apnoea attacks progressively decreased during the treatment of gastrooesophageal reflux with omeprazole. This fact suggests that gastrooesophageal reflux may play a role in triggering and/or worsening obstructive sleep apnoea.

Locked nucleic acids (LNA): versatile tools for designing oligonucleotide decoys with high stability and affinity.

Double-stranded oligodeoxynucleotides (ODN) containing the consensus binding sequence of a transcription factor are valuable tools for the manipulation of gene expression at the transcriptional level by means of the decoy strategy. The approach involves flooding the cells with enough ODN decoy to compete for binding of the transcription factor with its consensus sequence in target genes. The technique has been proven effective in vitro and in vivo, suggesting its use in therapy. Therefore, great attention has been recently focused on chemical modifications enhancing biostability of the oligonucleotides so as to improve their pharmacological properties. Unfortunately, benefits in terms of nuclease resistance have been often negated by a decrease in the affinity and/or specificity of transcription factor binding. To circumvent these problems, circular dumbbell and chimeric decoy oligonucleotides, the latter comprising a central stretch of transcription factor recruiting deoxynucleotides flanked by modified nucleotides, have been introduced. Nevertheless, these approaches have the limitation of leaving the ODNs still sensitive to endonuclease cleavage. To address these concerns, we have recently investigated the use of a new class of nucleotide analogs termed locked nucleic acids (LNA) in the designing of decoy molecules for the transcription factor kappaB (NF-kappaB). In this article, we review the advantages of LNA in the design of ODN decoys pointing to the feasibility of introducing modifications in the transcription factor binding sequence in order to obtain molecules with increased stability compared to end-capped ODNs, while remaining efficiently recognized by NF-kappaB.

Modulation of ICAM-1 expression in ECV304 cells by macrophage-released cytokines.

Transendothelial leukocyte trafficking during inflammation requires the expression of adhesion molecules such as human intercellular adhesion molecule-1 (ICAM-1). ICAM-1 is constitutively expressed on the surface of endothelial cells and its levels increase in response to a variety of inflammatory mediators, including cytokines. Monocyte/macrophage cells play a crucial role in this context because, upon stimulation, they release proinflammatory cytokines which are responsible for the upregulation of adhesion molecules in endothelial cells. In the present study we investigated whether the modulation of macrophage activation and cytokine release is able to modulate ICAM-1 expression in endothelial cells. Dexamethasone was selectively delivered to macrophages by means of a red blood cell-mediated delivery system. Subsequent stimulation of macrophages by lipopolysaccharide (LPS) was found to inhibit NF-kB activation and tumor necrosis factor-alpha (TNF-alpha) release [R. Crinelli, A. Antonelli, M. Bianchi, L. Gentilini, S. Scaramucci, and M. Magnani (2000) Blood Cells Mol. Dis. 26, 211-222]. Incubation with conditioned medium derived from LPS-stimulated macrophages receiving dexamethasone resulted in a 45% inhibition of ICAM-1 mRNA expression in ECV304 cells. In the same experimental system this reduced ICAM-1 expression was paralleled by a reduced NF-kB DNA binding activity and a twofold higher level of IkB(alpha) in the cytosol of endothelial cells. Activation of ICAM-1 expression in ECV304 cells by macrophage-conditioned medium is not due to IFN-gamma stimulation since STAT-1 DNA binding remained unchanged. Furthermore, treatment of the macrophage-conditioned medium with a TNF-alpha-inactivating antibody resulted in the complete abrogation of induced ICAM-1 expression. These results suggest that TNF-alpha is the main cytokine released by LPS-stimulated macrophages able to promote ICAM-1 gene expression in endothelial cells. Modulation of the NF-kB activation pathway in macrophages by targeted delivery of dexamethasone could potentially be used as a therapeutic strategy with which to inhibit the expression of ICAM-1 in endothelial cells.

Selective inhibition of NF-kB activation and TNF-alpha production in macrophages by red blood cell-mediated delivery of dexamethasone.

Glucocorticoids are a widely used class of anti-inflammatory and immunosuppressive drugs, but their therapeutic use is limited by endocrine and metabolic side effects that they produce when given systemically. Since cells of the monocyte/macrophage lineage play an important role in the pathogenesis of several autoimmune and inflammatory diseases, a drug-delivery system which targets phagocytic cells was studied. We had previously demonstrated that dexamethasone, a potent glucocorticoid analogue, can be encapsulated in erythrocytes and selectively delivered to macrophages. In addition, lipopolysaccharide (LPS) stimulation of dexamethasone-targeted macrophages results in the suppression of TNF-alpha secretion. In this paper we demonstrate that the administration of dexamethasone to macrophages by means of opsonized red blood cells allows efficient interference with NF-kB activation. This NF-kB repression was in part mediated by induction of IkBalpha gene transcription and, as a consequence, by an increased rate of IkBalpha protein synthesis. Furthermore, NF-kB inactivation correlated with downmodulation of TNF-alpha mRNA expression, demonstrating that suppression of TNF-alpha production in dexamethasone-targeted cells occurs at the transcriptional level.

Activation of the ubiquitin proteolytic system in murine acquired immunodeficiency syndrome affects IkappaBalpha turnover.

Murine acquired immunodeficiency syndrome (MAIDS) is a complex immunopathology caused by a defective murine leukemia virus (LP-BM5) that mainly targets B-lymphocytes. Lymphadenophathy, splenomegaly, hypergammaglobulinemia and progressive immunodeficiency are prominent features of MAIDS. Previously, we showed that the ubiquitin proteolytic system was upregulated in infected lymph nodes [Crinelli, R., Fraternale, A., Casabianca, A. & Magnani, M. (1997) Eur. J. Biochem. 247, 91-97]. In this report, we demonstrate that increased 26S proteasome activity is responsible for accelerated turnover of the IkappaBalpha inhibitor in lymph node extracts derived from animals with MAIDS. The molecular mechanisms mediating IkappaBalpha proteolysis involved constitutive phosphorylation of IkappaBalpha at Ser32 and Ser36 and subsequent ubiquitination, suggesting persistent activation of an NF-kappaB inducing pathway. Interestingly, enhanced IkappaBalpha degradation did not result in enhanced NF-kappaB DNA binding activity, but rather in a different subunit composition. The modulation of NF-kappaB/IkappaB system may affect multiple immunoregulatory pathways and may in part explain the mechanisms leading to the profound immune dysregulation involved in MAIDS pathogenesis.

Efficient inhibition of macrophage TNF-alpha production upon targeted delivery of K48R ubiquitin.

K48R ubiquitin (K48R-Ub) is an analogue of native ubiquitin that does not form polyubiquitin chain conjugates. Targeted delivery of this recombinant mutant ubiquitin to human macrophages results in an intracellular increase in the ubiquitin analogue. IkappaBalpha polyubiquitination and degradation were significantly inhibited in K48R-Ub targeted macrophages upon stimulation with lipopolysaccharide. The ability to reduce IkappaBalpha degradation was also associated with a reduced production of TNF-alpha, the gene of which is under NF-kappaB control. At a concentration of 0.1 microM, dexamethasone was less effective than K48R-Ub in preventing IkappaBalpha depletion and TNF-alpha release. These data suggest that ubiquitin analogues are potent suppressors of TNF-alpha release in macrophages.

The "Brisighella Terme" Project: effectiveness of preventive medicine in thermal ambient. Hematochemical parameters.

BACKGROUND: The main aims of the Brisighella Terme Project are: 1. evaluation of feasibility and effectiveness of preventive medicine intervention in thermal ambient; 2. identification of subjects with cardiovascular risk factors; 3. to give patients informations on risk factor correction. The data of this work concern the hematochemical parameters: CT, HDL-CT, LDL-CT, TG, ApoA1, ApoB, fibrinogen, GOT, GPT, CPK, glucose, uric acid. METHODS: CT, HDL-CT (after precipitation of the non-HDL fractions), TG, glucose, uric acid are evaluated by enzymatic-colorimetric reactions; GOT, GPT, CK by enzymatic method. ApoA1, ApoB, fibrinogen by immunoturbidimetric methods. LDL-CT is calculated by the Friedewald formula. RESULTS: 390 subjects spontaneously adhered to the Brisighella Terme Project. Of these subjects 38% requested laboratory service and we observed a 47% increment, from 1995 to 1996, with regard to this request. Females showed higher mean values than males of these parameters: CT, LDL-CT, HDL-CT, ApoA1, ApoB, fibrinogen, CPK. 55% of females had LDL-CT > 159 mg/dl, values considered high risk for cardiovascular diseases. 36% of males presented HDL-CT < 40 mg/dl, with 2 cases < 25 mg/dl. TG values > 399 mg/dl were found only in males (2%). We identified new cases of hypertriglyceridaemia, hypercholesterolaemia and hypoHD Laemia; these metabolic pathologies had not yet been diagnosed, whereas the patients already knew they were affected by hyperglicaemia or hyperuricaemia. CONCLUSIONS: People's interest in the Brisighella Terme Project, new case identification, the possibility of providing correct information about risk factors and healthy life style confirm the feasibility and effectiveness of preventive medicine in a thermal ambient.

Diagnostic evaluation of alanine aminopeptidase as serum marker for detecting cancer.

Alanine aminopeptidase (AAP), carcinoembryonic antigen (CEA), and tissue polypeptide antigen (TPA) were measured in 40 patients with breast and thyroid cancer and in 40 patients suffering from benign tumors and benign noninflammatory diseases. AAP activity was significantly increased (P < 0.001) in all cancer patients considered together. TPA shows a remarkable diagnostic sensitivity but a low specificity. For CEA an inverse situation is observed. Evaluation of the predictive value of the assay of AAP revealed a sufficient sensitivity, a good specificity, a sufficient predictive value of both positive and negative results, and a good efficiency. We believe that the test, if supported by other information, can be useful in the diagnosis of breast and thyroid cancer.