Study of Aberrant Modifications in Peptides as a Test Bench to Investigate the Immunological Response to Non-Enzymatic Glycation.

A side effect of diabetes is formation of glycated proteins and, from them, production of advanced early glycation end products that could determine aberrant immune responses at the systemic level. We investigated a relevant aberrant post-translational modification (PTM) in diabetes based on synthetic peptides modified on the lysine side chain residues with 1-deoxyfructopyranosyl moiety as a possible modification related to glycation. The PTM peptides were used as molecular probes for detection of possible specific autoantibodies developed by diabetic patients. The PDC-E2(167-186) sequence from the pyruvate dehydrogenase complex was selected and tested as a candidate peptide for antibody detection. The structure-based designed type I' ß-turn CSF114 peptide was also used as a synthetic scaffold. Twenty-seven consecutive type 1 diabetic patients and 29 healthy controls were recruited for the study. In principle, the 'chemical reverse approach', based on the use of patient sera to screen the synthetic modified peptides, leads to the identification of specific probes able to characterize highly specific autoantibodies as disease biomarkers of autoimmune disorders. Quite surprisingly, both peptides modified with the (1-deoxyfructosyl)-lysine did not lead to significant results. Both IgG and IgM differences between the two populations were not significant. These data can be rationalized considering that i) IgGs in diabetic subjects exhibit a high degree of glycation, leading to decreased functionality; ii) IgGs in diabetic subjects exhibit a privileged response vs proteins containing advanced glycation products (e.g., methylglyoxal, glyoxal, glucosone, hydroimidazolone, dihydroxyimidazolidine) and only a minor one with respect to (1-deoxyfructosyl)-lysine.

Rapid test for fecal calprotectin levels in children with Crohn disease.

Assessment of fecal calprotectin, a surrogate marker of mucosal inflammation, is a promising means to monitor therapeutic response in pediatric inflammatory bowel disease, especially if the result is readily available. We tested the performance of a novel calprotectin rapid test, Quantum Blue, versus the conventional enzyme-linked immunosorbent assay in 134 stool samples from 56 pediatric patients with Crohn disease. The intraclass correlation coefficient analysis reflected good agreement (intraclass correlation coefficient 0.97 [95% confidence interval 0.95-0.98]) but agreement was better in lower values, where dilutions were not required. Using a cutoff of 100 µg/g for normal values, the percentage agreement between the 2 tests was 87%. The optimal cutoff values to guide clinical decisions in the therapy of inflammatory bowel disease have yet to be determined.

The London Position Statement of the World Congress of Gastroenterology on Biological Therapy for IBD with the European Crohn's and Colitis Organisation: pregnancy and pediatrics.

Women with inflammatory bowel disease (IBD) have similar rates of fertility to the general population, but have an increased rate of adverse pregnancy outcomes compared with the general population, which may be worsened by disease activity. Infertility is increased in those undergoing ileal pouch-anal anastomosis. Anti-tumor necrosis factor therapy in pregnancy is considered to be low risk and compatible with use during conception in men and women and during pregnancy in at least the first two trimesters. Infliximab (IFX) and certolizumab pegol are also compatible with breastfeeding, but safety data for adalimumab (ADA) are awaited. The safety of natalizumab during pregnancy is unknown. For children with Crohn's disease (CD), IFX is effective at inducing and maintaining remission. Episodic therapy is not as effective as scheduled infusions. Disease duration in children does not appear to affect the efficacy of IFX. IFX promotes growth in prepubertal and early pubertal Crohn's patients. It is also effective for the treatment of extraintestinal manifestations. ADA is effective for children with active CD and for maintaining remission, even if they have lost response to IFX, although there are fewer data. Vaccination of infants exposed to biological therapy in utero should be given at standard schedules during the first 6 months of life, except for live-virus vaccines such as rotavirus. Inactivated vaccines may be safely administered to children with IBD, even when immunocompromised.

Further insights into the role of T222P variant of RXFP2 in non-syndromic cryptorchidism in two Mediterranean populations.

The aetiopathogenesis of isolated cryptorchidism remains largely unknown. Mutation screenings in the most relevant candidate genes for testicular maldescent lead to controversial data in the literature. In particular, the role of the T222P genetic variant of the RXFP2 gene is still debated. Given the controversies, the aim of this study was to provide further data on this genetic variant in two Mediterranean populations. A total of 577 subjects from Spain and 550 from Italy (with and without a history of cryptorchidism) were analysed. The T222P substitution was found in both unilateral and bilateral cases and in a total of 12 controls. These data exclude a clear-cut cause-effect relationship between T222P variant and testicular maldescent. The T222P variant was found at a similar frequency in both cases and controls in the Spanish population, whereas in Italy, the frequency of T222P resulted significantly higher in the cryptorchid group (p = 0.031). The observed difference between the two countries and the highly variable phenotypic expression of the T222P variant may depend on the genetic background or on environmental conditions. The haplotype analysis of the RXFP2 gene in T222P carriers and their parents showed that this variant is linked to the previously inferred C-C-G-A-13 haplotype and consequently provides further support to the 'founder effect' hypothesis. In conclusion, our data indicate that T222P is a frequent variant in the Spanish population with no pathogenic effect. Although in Italy it seems to confer a mild risk (odds ratio = 3.17, 95% confidence interval: 1.07-9.34) to cryptorchidism, the screening for this variant for diagnostic purposes is not advised because of the relatively high frequency of control carriers (1.4% of Italian men without a history of cryptorchidism).

Methotrexate in paediatric ulcerative colitis: a retrospective survey at a single tertiary referral centre.

BACKGROUND: Patients with ulcerative colitis often receive thiopurines as immunomodulators (IMs) to maintain remission and avoid corticosteroids. If unresponsive or intolerant to these agents, patients are treated with methotrexate, an antimetabolite never assessed in paediatric ulcerative colitis. AIM: To describe the experience with methotrexate in children with ulcerative colitis. METHODS: Thirty-two patients (median age 13.9 years) received methotrexate. Pediatric Ulcerative Colitis Activity Index (PUCAI) and use of corticosteroids were the main outcomes evaluated at baseline and at 3, 6 and 12 months. RESULTS: Indications to methotrexate were azathioprine unresponsiveness in 18 patients, azathioprine intolerance/toxicity in 10 and spondyloarthropathy in four. Response or remission was achieved in 72%, 63% and 50% of patients at 3, 6 and 12 months respectively. Mean PUCAI were 49.5 ± 23.3 at baseline and 32.9 ± 21.9, 29.5 ± 21.8 and 29.4 ± 19.9 at 3, 6 and 12 months respectively (P: 0.03). At the beginning of methotrexate, 16 patients (50%) received corticosteroids that were discontinued in 13 of them (81%) by 6 months. At the end of the study, 11 patients (33%) needed short courses of corticosteroids for disease relapse. CONCLUSIONS: Methotrexate may be useful in treating children with ulcerative colitis, although large, controlled trials are warranted to define better its effectiveness.

Persistence of expression of the TMPRSS2:ERG fusion gene after pre-surgery androgen ablation may be associated with early prostate specific antigen relapse of prostate cancer: preliminary results.

BACKGROUND: The recently identified TMPRSS2: ERG fusion gene is a candidate oncogene for prostate cancer (PCa). SUBJECTS AND METHODS: We have tested for the presence of this gene in tumor samples from 84 patients who had radical prostatectomy in 1998-2000. Sixty patients (group A) had surgery only; 24 patients (group B) received androgen ablation therapy for 3 months before surgery. The occurrence of the rearrangement was evaluated by RT-PCR and by fluorescent in situ hybridization analysis. RESULTS: A TMPRSS2:ERG fusion gene was present and expressed, as demonstrated by RT-PCR, in 84% of patients in group A and in 54% of patients in group B (p=0.01). The presence of TMPRSS2:ERG transcripts and the levels of ERG RNA, measured by quantitative Real Time-PCR, did not correlate significantly with clinical and pathologic characteristics of the tumors. In patients of group A, but not in those of group B, ERG expression showed a negative correlation with the Gleason score (p=0.0001). Histochemical analysis showed that ERG expression is limited to tumor cells, and in group A patients (but not in group B patients) it is limited to those glands that express TMPRSS2:ERG. CONCLUSION: The lower proportion of patients expressing TMPRSS2: ERG in group B suggests that androgen ablation inhibits the expression of TMPRSS2:ERG. Moreover, in group B, but not in group A, patients with expression of the fusion gene had earlier prostate specific antigen recurrence (p=0.007). Although preliminary, the data indicate that tumors in which pre-surgery androgen ablation fails to suppress expression of the fusion gene have a higher risk of recurrence.

Electrostatic interactions in phospholipid membranes revealed by coherent 2D IR spectroscopy.

The inter- and intramolecular interactions of the carbonyl moieties at the polar interface of a phospholipid membrane are probed by using nonlinear femtosecond infrared spectroscopy. Two-dimensional IR correlation spectra separate homogeneous and inhomogeneous broadenings and show a distinct cross-peak pattern controlled by electrostatic interactions. The inter- and intramolecular electrostatic interactions determine the inhomogeneous character of the optical response. Using molecular dynamics simulation and the nonlinear exciton equations approach, we extract from the spectra short-range structural correlations between carbonyls at the interface.

Partial AZFc deletions in infertile men with cryptorchidism.

BACKGROUND: A specific type of partial AZFc deletion, called 'gr/gr' deletion, was recently proposed as genetic risk factor for spermatogenic impairment and testis cancer. Since both pathologies can be part of the testicular dysgenesis syndrome (TDS), we aimed to define the role of 'gr/gr' deletion in the aethiopathogenesis of another component of the TDS: cryptorchidism. METHODS: A total of 146 cryptorchid and 140 infertile patients without a history of cryptorchidism were screened with a sequence tagged site plus/minus method and further confirmed and characterized by CDY1/DAZ gene dosage and copy analysis. RESULTS: The observed deletion frequency was 4.2% in cryptorchid and 5% in non-cryptorchid patients. Moreover, no differences in the CDY1/DAZ patterns were observed among the two groups. A significant difference in deletion frequency was present only when cryptorchid patients were compared with normospermic controls (P < 0.03). CONCLUSIONS: Our data show no relationship between 'gr/gr' deletion and cryptorchidism, however, provide further evidence of the deleterious effect of the 'gr/gr' deletion on spermatogenesis. The screening for 'gr/gr' deletion may therefore be proposed before ICSI to all patients with severe male factor infertility, without the exclusion of those with cryptrochidism, since this genetic risk factor for spermatogenic impairment will be transmitted to the male offspring.

Molecular analysis of estrogen receptor alpha gene AGATA haplotype and SNP12 in European populations: potential protective effect for cryptorchidism and lack of association with male infertility.

BACKGROUND: A specific haplotype (AGATA) in the estrogen receptor alpha (ER1) gene was recently described as a new risk factor for cryptorchidism in the Japanese population. In this ethnic group, single-nucleotide polymorphism 12 (SNP12) was concluded to be the tag SNP for the AGATA haplotype. MATERIALS AND METHODS: A large group of patients (total number=335) and controls (total number=567) of two Caucasian populations were analysed for the AGATA haplotype and SNP12 to verify whether this genetic variant and its tag SNP were associated with cryptorchidism or with severe spermatogenic failure. RESULTS: We confirm that SNP12 is the tag SNP for the AGATA haplotype also in Caucasians. However, in contrast with the Japanese population we found a protective effect for ESR1 SNP12 on cryptorchidism in the Italian population. No association between SNP12 and severe spermatogenic disturbances was observed. CONCLUSIONS: The observed associations (although with opposite effect) with cryptorchidism encourage future studies on independent cases and controls from different ethnic and geographic origins. On the other hand, in contrast with other ESR1 polymorphisms, SNP12 polymorphism is not associated with severe male factor infertility in two independent European population.

Sphingosine 1-phosphate induces myoblast differentiation through Cx43 protein expression: a role for a gap junction-dependent and -independent function.

Although sphingosine 1-phosphate (S1P) has been considered a potent regulator of skeletal muscle biology, acting as a physiological anti-mitogenic and prodifferentiating agent, its downstream effectors are poorly known. In the present study, we provide experimental evidence for a novel mechanism by which S1P regulates skeletal muscle differentiation through the regulation of gap junctional protein connexin (Cx) 43. Indeed, the treatment with S1P greatly enhanced Cx43 expression and gap junctional intercellular communication during the early phases of myoblast differentiation, whereas the down-regulation of Cx43 by transfection with short interfering RNA blocked myogenesis elicited by S1P. Moreover, calcium and p38 MAPK-dependent pathways were required for S1P-induced increase in Cx43 expression. Interestingly, enforced expression of mutated Cx43(Delta130-136) reduced gap junction communication and totally inhibited S1P-induced expression of the myogenic markers, myogenin, myosin heavy chain, caveolin-3, and myotube formation. Notably, in S1P-stimulated myoblasts, endogenous or wild-type Cx43 protein, but not the mutated form, coimmunoprecipitated and colocalized with F-actin and cortactin in a p38 MAPK-dependent manner. These data, together with the known role of actin remodeling in cell differentiation, strongly support the important contribution of gap junctional communication, Cx43 expression and Cx43/cytoskeleton interaction in skeletal myogenesis elicited by S1P.

Neutral/alkaline and acid ceramidase activities are actively released by murine endothelial cells.

Ceramidases (CDase(s)) play a key role in sphingolipid metabolism by hydrolyzing ceramide into sphingosine. Here we report that murine endothelial cells, macrophages, and human fibroblasts are all able to release acid as well as neutral/alkaline CDase activities in the culture medium. Endothelial cells were characterized by the highest specific activity of cellular as well as secreted CDases. The release of both enzymatic activities was reduced by protein synthesis inhibitor cycloheximide but was unaffected by the blocking of RNA transcription with actinomycin D. The discharge of acid and neutral/alkaline CDases was also diminished by brefeldin A, a fungal metabolite which disrupts Golgi apparatus. Remarkably, treatment of endothelial cells with bradykinin resulted in a significant increase of neutral/alkaline but not acid CDase release. This report represents the first evidence for the existence of constitutive and regulated release of CDase activities by endothelial cells. In view of the known ability of these cells to secrete sphingomyelinase, this finding suggests that CDase may participate in extracellular sphingomyelin metabolism which is presently known to have a role in atherogenesis and could be involved in other physiological or pathological events.