Characterization of TG2 and TG1-TG2 double knock-out mouse epidermis.

Transglutaminases (TGs) are a family of enzymes that catalyse the formation of isopeptide bonds between the γ-carboxamide groups of glutamine residues and the ε-amino groups of lysine residues leading to cross-linking reactions among proteins. Four members, TG1, TG2, TG3, and TG5, of the nine mammalian enzymes are expressed in the skin. TG1, TG3 and TG5 crosslinking properties are fundamental for cornified envelope assembly. In contrast, the role of TG2 in keratinization has never been studied at biochemical level in vivo. In this study, taking advantage of the TG2 knock-out (KO) and TG1 heterozygous mice, we generated and characterized the epidermis of TG1-TG2 double knock-out (DKO) mice. We performed morphological analysis of the epidermis and evaluation of the expression of differentiation markers. In addition, we performed analysis of the amino acid composition from isolated corneocytes. We found a significant change in amino acid composition in TG1KO cornified cell envelopes (CEs) while TG2KO amino acid composition was similar to wild-type CEs. Our results confirm a key role of TG1 in skin differentiation and CE assembly and demonstrate that TG2 is not essential for CE assembly and skin formation.

Attachment style predict compliance, quality of life and renal function in adult patients after kidney transplant: preliminary results.

AIM: Aim of this study was to evaluate the association between attachment style, compliance, quality of life and renal function in adult patients after kidney transplantation. METHODS: A total of 43 adult patients who received a kidney transplant more than 3 months before were enrolled and were asked to complete two Self-Report questionnaires: Attachment Style Questionnaire (ASQ-40) and Short Form Health Survey (SF-36). Also compliance was measured using appropriate questions. RESULTS: Linear regression analysis showed associations between the confidence in relationships (ASQ-40) and compliance [beta = -0.37; B = -0.02; t(41) = -2.51; p = 0.02]; aspects of anxious attachment style (ASQ-40) and creatinine levels [beta = 0.3; B = 0.13; t(41) = 2.03; p = 0.04]; aspects of avoidant attachment style (ASQ-40) and compliance [beta = -0.37; B = -3.15; t(41) = -2.35; p = 0.02]. Patients who exhibited avoidant attachment had a significantly better perception of their own general health than patients with anxious [F(2,37) = 6.8; p < 0.05] or secure attachment; however, they had a worse perception regarding role limitations due to emotional problems, compared to patients with anxious attachment [F(2,37) = 6.4; p < 0.05]. DISCUSSION: The results of this study suggest that the evaluation of the attachment style in adult kidney transplant patients can contribute to plan a goal-directed psychological support program for these patients, in order to increase their compliance. The association between aspects of anxious attachment style and creatinine level needs more investigations.

Transglutaminase 5 is regulated by guanine-adenine nucleotides.

Transglutaminases (TGases) are Ca2+-dependent enzymes capable of catalysing transamidation of glutamine residues to form intermolecular isopeptide bonds. Nine distinct TGases have been described in mammals, and two of them (types 2 and 3) are regulated by GTP/ATP. TGase2 hydrolyses GTP and is therefore a bifunctional enzyme. In the present study, we report that TGase5 is also regulated by nucleotides. We have identified the putative TGase5 GTP-binding pocket by comparative amino acid sequence alignment and homology-derived three-dimensional modelling. GTP and ATP inhibit TGase5 cross-linking activity in vitro, and Ca2+ is capable of completely reversing this inhibition. In addition, TGase5 mRNA is not restricted to epidermal tissue, but is also present in different adult and foetal tissues, suggesting a role for TGase5 outside the epidermis. These results reveal the reciprocal actions of Ca2+ and nucleotides with respect to TGase5 activity. Taken together, these results indicate that TGases are a complex family of enzymes regulated by calcium, with at least three of them, namely TGase2, TGase3 and TGase5, also being regulated by ATP and GTP.

Emotional self-efficacy and alexithymia may affect compliance, renal function and quality of life in kidney transplant recipients: results from a preliminary cross-sectional study.

UNLABELLED: Recent studies show that alexithymia may influence compliance and quality of life in different clinical situations. The aim of this study was to evaluate the associations between alexithymia or emotional self-efficacy and compliance, quality of life (QoL) and renal function in renal transplant patients. METHODS: Forty-three patients were enrolled during a follow-up visit (>3 months post-transplant) and were asked to complete three self-report questionnaires (TAS-20, SF-36, RESE) to answer the following items: "In the past four weeks, how many times did you fail to take your prescribed dose?" and "How would you rate your adherence levels from 0 to 100?" (visual analogue scale). RESULTS: Alexithymia was positively correlated with non-compliance (r=.314; p=.04), and negatively with QoL dimensions. Analysis of variance confirmed that patients with high levels of alexithymia reported a negative perception of their QoL (mental health: F(1,41)=7,6; p=.008) and lower levels of compliance (F(1,41)=12,5; p=.001) compared with patients with low levels of alexithymia. The self-efficacy in the management of negative emotions was significantly correlated (r=-.314; p=.04) with creatinine levels and positively with the QoL (mental health: r=.421; p=.005). DISCUSSION: The inability to recognize and express emotions, as well as the ability to manage negative emotions, may influence compliance and QoL of renal transplant patients. Focused psychological support could be useful in these patients in order to increase their compliance and QoL.

Inactive and highly active, proteolytically processed transglutaminase-5 in epithelial cells.

Transglutaminases (TGs) are Ca(2+)-dependent enzymes capable of catalyzing transamidation of glutamine residues to form intermolecular isopeptide bonds. These enzymes are involved in various biological phenomena, including blood coagulation, wound healing, cell death, tissue repair, and terminal differentiation of keratinocytes. Among the TG-family members, TG5 is one of the latest identified enzymes and therefore the less characterized at the functional level. In this work, we reported that TG5 is proteolytically processed in the baculovirus expression system and in mammal epithelial cells. Similar to other members of the TG family-TG1, TG3, and factor XIIIa -, TG5 full-length enzyme has very low enzymatic activity, while the 53-kDa proteolytically processed form is highly active.

Dominant and recessive COL6A1 mutations in Ullrich scleroatonic muscular dystrophy.

In this study, we characterized five Ullrich scleroatonic muscular dystrophy patients (two Italians, one Belgian, and two Turks) with a clinical phenotype showing different degrees of severity, all carrying mutations localized in COL6A1. We sequenced the three entire COL6 complementary DNA. Three of five patients have recessive mutations: two patients (P1and P3) have homozygous single-nucleotide deletions, one in exon 9 and one in exon 22; one patient (P2) has a homozygous single-nucleotide substitution leading to a premature termination codon in exon 31. The nonsense mutation of P2 also causes a partial skipping of exon 31 with the formation of a premature termination codon in exon 32 in 15% of the total COL6A1 messenger RNA. The remaining two patients carry a heterozygous glycine substitution in exons 9 and 10 inside the triple-helix region; both are dominant mutations because the missense mutations are absent in the DNA of their respective parents. As for the three homozygous recessive mutations, the apparently healthy consanguineous parents all carry a heterozygous mutated allele. Here, for the first time, we report a genotype-phenotype correlation demonstrating that heterozygous glycine substitutions in the triple-helix domain of COL6A1 are dominant and responsible for a milder Ullrich scleroatonic muscular dystrophy phenotype, and that recessive mutations in COL6A1 correlate with more severe clinical and biochemical Ullrich scleroatonic muscular dystrophy phenotypes.