Studies on sporadic non-syndromic thoracic aortic aneurysms: II. Alterations of extra-cellular matrix components and focal adhesion proteins

Background Sporadic non-syndromic thoracic aortic aneurysms (SNSTAAs) are less well understood than familial non-syndromic or syndromic ones. Here, we focused on morphologic and molecular changes of the extracellular matrix of the tunica media of SNSTAAs. Design Single centre design. Methods Surgical media samples from seven SNSTAAs and seven controls underwent quantitative polymerase chain reaction, proteomics-bioinformatics, immunoblotting, histology and immunohistochemistry analysis. Results A down-regulation of Decorin mRNA with unchanged protein levels associated with a remarkable increase of collagen fibres. A reduced and distorted network of elastic fibres partnered with an attenuated expression of microfibril-associated glycoprotein1 despite the rise of MFAP2 gene-encoded mRNA levels. An increasingly proteolysed paxillin (55 kDa PXN), a focal adhesion protein, combined with an upregulated 62 kDa PXN holoprotein, without changes in amount and phosphorylation of focal adhesion kinase (pp125^FAK). The upregulation of SPOCK2-encoded Testican2 proteoglycan and of ectodysplasin (EDA) protein was coupled with a down-regulation of EDA2 receptor (EDA2R). Conclusions Several tunica media extracellular matrix-related changes favour SNSTAA development. A steady level of decorin and a microfibril-associated glycoprotein1 protein shortage cause the assembly of structurally defective collagen and elastic fibres. Up-regulation of PXN holoproteins perturbs PXN/pp125^FAK interaction and focal adhesion functioning. Testican2 up-regulation suppresses the membrane-type matrix metalloproteinase inhibiting activities of other SPOCK family members thus enhancing extracellular matrix proteolysis. Finally, the altered EDA•EDA2R signalling would impact on the remodelling of SNSTAA tunica media. Altogether, our results pave the way to a deeper molecular understanding of SNSTAAs necessary to identify their early diagnostic biochemical markers.

Clinical outcomes of stapled transanal rectal resection for obstructed defaecation syndrome at 10-year follow-up

AIM

The long-term efficacy of stapled transanal rectal resection (STARR) for surgical management of obstructed defaecation syndrome (ODS) has not been evaluated. Therefore, we investigated the long-term efficacy (> 10 years) of STARR for treatment of ODS related to rectocele or rectal intussusception and the factors that predict treatment outcome.

METHOD

This study was a retrospective cohort analysis conducted on prospectively collected data. Seventy-four consecutive patients who underwent STARR for ODS between January 2005 and December 2006 in two Italian hospitals were included.

RESULTS

Seventy-four patients [66 women; median age 61 (29-77) years] underwent STARR for ODS. No serious postoperative complications were recorded. Ten years postoperatively, 60 (81%) patients completed the expected follow-up. Twenty-three patients (38%) reported persistent perineal pain and 13 (22%) experienced the urge to defaecate. ODS symptoms recurred in 24 (40%) patients after 10 years. At the 10-year follow-up, 35% of patients were very satisfied and 28% would recommend STARR and undergo the same procedure again if necessary. In contrast, 21% of patients would not select STARR again. Previous uro-gynaecological or rectal surgery and high constipation scores were identified as risk factors for recurrence.

CONCLUSIONS

Stapled transanal rectal resection significantly improves the symptoms of ODS in the short term. In the long term STARR is less effective, however.

Studies on sporadic non-syndromic thoracic aortic aneurysms: 1. Deregulation of Jagged/Notch 1 homeostasis and selection of synthetic/secretor phenotype smooth muscle cells

Background

Sporadic non-syndromic thoracic aortic aneurysms (SNSTAAs) are less well understood than familial non-syndromic or syndromic ones. The study aimed at defining the peculiar morphologic and molecular changes occurring in the media layer of SNSTAAs.

Design

This study was based on a single centre design.

Methods

Media layer samples taken from seven carefully selected SNSTAAs and seven reference patients (controls) were investigated via quantitative polymerase chain reaction, proteomics-bioinformatics, immunoblotting, quantitative histology, and immunohistochemistry/immunofluorescence.

Results

In SNSTAAs media, aortic smooth muscle cells numbers were halved due to an apoptotic process coupled with a negligible cell proliferation. Cystathionine γ-lyase was diffusely up-regulated. Surviving aortic smooth muscle cells exhibited diverging phenotypes: in inner- and outer-media contractile cells prevailed, having higher contents of smooth-muscle-α-actin holoprotein (45-kDa) and of caspase-3-cleaved smooth-muscle-α-actin 25-kDa fragments; in mid-media, aortic smooth muscle cells exhibited a synthetic/secretor phenotype, down-regulating vimentin, but up-regulating glial fibrillary acidic protein, trans-Golgi network 46 protein, Jagged1 (172-kDa) holoprotein, and Jagged1’s receptor Notch1. Extracellular soluble Jagged1 (42-kDa) fragments accumulated.

Conclusions

In SNSTAAs, there is a relentless aortic smooth muscle cells attrition caused by the up-regulated cystathionine γ-lyase. In mid-media, synthetic/secretor aortic smooth muscle cells intensify Jagged1/NOTCH1 signalling in the attempt to counterbalance the weakened aortic wall, due to aortic smooth muscle cells net loss and mechanical stress. Synthetic/secretor aortic smooth muscle cells are apoptosis-prone, and the accruing thrombin-cleaved Jagged1 fragments counteract the otherwise useful effects of Jagged1/NOTCH1 signalling, thus hampering tissue homeostasis/remodelling, and aortic smooth muscle cells adhesion, differentiation, and migration.

A novel synonymous substitution in the GCK gene causes aberrant splicing in an Italian patient with GCK-MODY phenotype

GCK gene analysis in an Italian MODY patient revealed a novel synonymous substitution in exon 4 (c.459T>G; p.Pro153Pro) resulting in an aberrant transcript lacking the last eight codons of the same exon. Our findings emphazise the importance of not underestimating synonymous variations when screening for disease-causing mutations.

Exocrine gastric secretion and gastritis: pathophysiological and clinical relationships

Gastric exocrine secretion, both acid and non-acid, is required for micronutrients absorption, such as iron, calcium and vitamin B12, drugs absorption, protein digestion. Clinical presentation of a gastric secretion impairment might be then characterized by the presence of both gastrointestinal and non-gastrointestinal specific symptoms (i.e. anemia) or to a non-response to therapies. The main factor that impairs gastric exocrine secretion homeostasis is mucosal chronic inflammation that principally occurs after colonization by Helicobacter pylori (Hp). The extent and distribution of gastritis ultimately determine the clinical outcome linked to differences in gastric acid secretion status, the involvement of gastric body leading to a decrease in gastric exocrine secretion with possible progression to mucosal atrophy towards cancer. A correct clinical strategy in the management of Hp infected patients should be then to early identify body involvement, a diagnosis generally missed in that body biopsies are not routinely performed. The use of gastric serological markers, gastrin and pepsinogens, are helpful in suspecting the presence of mucosal atrophy but their diagnostic accuracy for non-atrophic chronic gastritis topography is not adequate despite a good specificity due to the low sensitivity, of all the available biomarkers. Gastric serology associated to anemia/iron-deficiency screening might nevertheless been helpful in the framing of patients that undergo endoscopy in order to highlight the need of extensive mucosal biopsies sampling.

Reconstruction and functional analysis of altered molecular pathways in human atherosclerotic arteries

Background

Atherosclerosis affects aorta, coronary, carotid, and iliac arteries most frequently than any other body vessel. There may be common molecular pathways sustaining this process. Plaque presence and diffusion is revealed by circulating factors that can mediate systemic reaction leading to plaque rupture and thrombosis.

Results

We used DNA microarrays and meta-analysis to study how the presence of calcified plaque modifies human coronary and carotid gene expression. We identified a series of potential human atherogenic genes that are integrated in functional networks involved in atherosclerosis. Caveolae and JAK/STAT pathways, and S100A9/S100A8 interacting proteins are certainly involved in the development of vascular disease. We found that the system of caveolae is directly connected with genes that respond to hormone receptors, and indirectly with the apoptosis pathway.

Cytokines, chemokines and growth factors released in the blood flux were investigated in parallel. High levels of RANTES, IL-1ra, MIP-1alpha, MIP-1beta, IL-2, IL-4, IL-5, IL-6, IL-7, IL-17, PDGF-BB, VEGF and IFN-gamma were found in plasma of atherosclerotic patients and might also be integrated in the molecular networks underlying atherosclerotic modifications of these vessels.

Conclusion

The pattern of cytokine and S100A9/S100A8 up-regulation characterizes atherosclerosis as a proinflammatory disorder. Activation of the JAK/STAT pathway is confirmed by the up-regulation of IL-6, STAT1, ISGF3G and IL10RA genes in coronary and carotid plaques. The functional network constructed in our research is an evidence of the central role of STAT protein and the caveolae system to contribute to preserve the plaque. Moreover, Cav-1 is involved in SMC differentiation and dyslipidemia confirming the importance of lipid homeostasis in the atherosclerotic phenotype.

Utility of combined use of plasma levels of chromogranin A and pancreatic polypeptide in the diagnosis of gastrointestinal and pancreatic endocrine tumors

BACKGROUND

Chromogranin A (CgA) is considered the most accurate marker in the diagnosis of gastro-entero-pancreatic (GEP) endocrine tumors. Pancreatic polypeptide (PP) has also been proposed to play this role, but then not used due to its low sensitivity. The aim of the present study was to determine whether the assessment of PP would improve the diagnostic reliability of CgA in patients with GEP tumors.

PATIENTS AND METHODS

Both markers were assessed in 68 patients [28 functioning (F), 40 non functioning (NF)]. Twenty-seven patients disease-free (DF) after surgery, and 24 with non-endocrine tumors (non-ETs) were used as control groups.

RESULTS

CgA sensitivity was: 96% in F, 75% in NF, 74% in pancreatic, and 91% in gastrointestinal (GI) tumors. Specificity was 89% vs DF, and 63% vs non-ETs. PP sensitivity was: 54% in F, 57% in NF, 63% in pancreatic, and 53% in GI tumors. Specificity was 81% vs DF, and 67% vs non-ETs. By combining the two markers a significant gain in sensitivity vs CgA alone was obtained: overall in GEP tumors (96% vs 84%, p = 0.04), in NF (95% vs 75%, p = 0.02), and in pancreatic (94% vs 74%, p = 0.04). More specifically, a 25% gain of sensitivity was obtained in the subgroup of NF pancreatic tumors (93% vs 68%, p = 0.04).

CONCLUSION

The combined assessment of PP and CgA leads to a significant increase in sensitivity in the diagnosis of GEP tumors, particularly in pancreatic NF.

[Poisons and men: historical, legal and toxicological aspects]

Humanity has always practised the poisoning. At first, magic and mistery characterized this ritual. Then, thanks to a more careful legislation and to empirical research it became subject of toxicology.

Thrombin regulates the expression of proangiogenic cytokines via proteolytic activation of protease-activated receptor-1

In addition to its central role in blood coagulation and hemostasis, human alpha-thrombin is a growth factor for a variety of cell types, including monocytes and endothelial cells, involved in the control of angiogenesis. Different cytokines produced by mononuclear cells have been implicated in angiogenic processes associated with tissue repair and certain human malignancies. We have previously shown that thrombin enhances proliferative responses in T lymphocytes. More recently, we reported that interferon-gamma-differentiated monocytes have increased expression of protease-activated receptor-1 (PAR-1) and increased thrombin binding. Since cytokines may be involved directly and indirectly in angiogenesis, we initiated studies to determine thrombin effects on the induction of cytokines, such as interleukin (IL)-1 and IL-6, in human mononuclear cells. IL-1 and IL-6 protein expression was significantly enhanced by thrombin (P<.05), as determined by enzyme-linked immunosorbent assay (ELISA). Treating mononuclear cells with the PAR-1 peptide, SFLLRN, has effects similar to those of thrombin. Thus, it appears that these thrombin effects are mediated through activation of PAR-1. These results confirm that thrombin is a strong activator of monocytes and could be involved in angiogenesis by inducing cytokines that could enhance the angiogenic process in tissue repair.