Chiara Cosma

The redox enzyme p66Shc contributes to diabetes and ischemia-induced delay in cutaneous wound healing

OBJECTIVE The redox enzyme p66Shc produces hydrogen peroxide and triggers proapoptotic signals. Genetic deletion of p66Shc prolongs life span and protects against oxidative stress. In the present study, we evaluated the role of p66Shc in an animal model of diabetic wound healing. RESEARCH DESIGN AND METHODS Skin wounds were created in wild-type (WT) and p66Shc−/− control and streptozotocin-induced diabetic mice with or without hind limb ischemia. Wounds were assessed for collagen content, thickness and vascularity of granulation tissue, apoptosis, reepithelialization, and expression of c-myc and β-catenin. Response to hind limb ischemia was also evaluated. RESULTS Diabetes delayed wound healing in WT mice with reduced granulation tissue thickness and vascularity, increased apoptosis, epithelial expression of c-myc, and nuclear localization of β-catenin. These nonhealing features were worsened by hind limb ischemia. Diabetes induced p66Shc expression and activation; wound healing was significantly faster in p66Shc−/− than in WT diabetic mice, with or without hind limb ischemia, at 1 and 3 months of diabetes duration and in both SV129 and C57BL/6 genetic backgrounds. Deletion of p66Shc reversed nonhealing features, with increased collagen content and granulation tissue thickness, and reduced apoptosis and expression of c-myc and β-catenin. p66Shc deletion improved response to hind limb ischemia in diabetic mice in terms of tissue damage, capillary density, and perfusion. Migration of p66Shc−/− dermal fibroblasts in vitro was significantly faster than WT fibroblasts under both high glucose and hypoxia. CONCLUSIONS p66Shc is involved in the delayed wound-healing process in the setting of diabetes and ischemia. Thus, p66Shc may represent a potential therapeutic target against this disabling diabetes complication.

Low molecular weight proteins in urines from healthy subjects as well as diabetic, nephropathic and diabetic-nephropathic patients : a MALDI study

Urine samples from healthy subjects as well as diabetic, nephropathic and diabetic-nephropathic patients were analyzed by matrix assisted laser desorption/ionization (MALDI) mass spectrometry in order to establish evidence of some possible differences in the peptide profile related to the pathological states. Multivariate analysis suggested the possibility of a distinction among the considered groups of patients. Some differences have been found, in particular, in the relative abundances of three ions at m/z 1912, 1219 and 2049. For these reasons, further investigation was carried out by MALDI/TOF/TOF to determine the sequence of these peptides and, consequently, to individuate their possible origin. By this approach, the peptide at m/z 1912 was found to originate from uromodulin, and its lower expression in the case of nephropathy can be well related to the pathological condition. Ions at m/z 2049 and 1219 originate from the collagen alpha-1(I) chain precursor and from the collagen alpha-5 (IV) chain precursor, respectively, and, also in this case, their different expressions can be related to the pathologies under investigation. The obtained data seem to indicate that urine is an interesting biological fluid to investigate on the peptide profile and to obtain, consequently, information on the dismetabolism activated by specific pathologies.

The effects of psyllium on lipoproteins in type II diabetic patients

We examined the effects of 2 months of psyllium treatment in optimizing metabolic control and lipoprotein profile, and its postprandial effects on lipids in type II diabetes. We recruited 40 type II diabetic patients who were on sulfonylureas and a controlled diet, sequentially assigning them to psyllium treatment (G1) or to a control group (G2) treated with dietary measures alone. After 2 months of treatment, body mass index, waist circumference, HbA1c (hemoglobin A1c) and fasting plasma glucose levels had significantly decreased in both groups. There were no postprandial differences in the lipoprotein profile between the two groups. Triglycerides were significantly lower in G1, but not in G2. Our study contributes toward elucidating the effects of psyllium on serum lipids, and suggests that psyllium treatment may help in reducing triglycerides (a known risk factor for cardiovascular disease) in type II diabetic patients.

A further investigation on a MALDI-based method for evaluation of markers of renal damage.

The validity of the urinary protein profile to characterize the pathological states of diabetic, nephropathic and diabetic-nephropathic patients was considered on the basis of previously obtained results by MALDI/MS, showing a different abundance ratio of the collagen alpha1 and alpha5 chain precursor fragments at m/z 1219 and 2049 and of the uromodulin precursor fragment at m/z 1912 observed in healthy subjects and patients; a larger number of subjects was examined and the obtained results were statistically evaluated. The p values related to the observed differences indicate that they are statistically significant when comparing all patients versus healthy controls, diabetic with normo or microalbuminuria versus nephropathic with advanced renal disease patients and diabetic with normo or microalbuminuria versus diabetic with advanced nephropathy patients. The scatter plot matrix gives evidence of the strict inverse relationship between the abundances of ions at m/z 1912 and 1219, the correlation coefficient being particularly high (r = 0.921, p < 0.001). The relationship between the true positive rate (sensitivity) and false positive rate (1-specificity) for every possible cutoff value in abundance of the considered ionic species was investigated through the receiver-operating characteristic (ROC) curve. The obtained data indicate that a good differentiation of nephropathic patients with advanced renal disease and diabetic patients with advanced nephropathy versus healthy subjects can be easily obtained by this approach.

Adiponectin Levels Are Reduced While Markers of Systemic Inflammation and Aortic Remodelling Are Increased in Intrauterine Growth Restricted Mother-Child Couple

Aim of the Study. To investigate the relationships between the adipocytokine levels, markers of inflammation, and vascular remodelling in pregnancies complicated by intrauterine growth restriction (IUGR). Materials and Methods. This was a retrospective study. One hundred and forty pregnant patients were enrolled. Adiponectin, leptin, tumor necrosis factor α (TNFα), interleukin-6 (IL-6), and C reactive protein (CRP) were assessed in IUGR, small for gestational age (SGA), and appropriate for gestational age (AGA) mother-child couples at delivery. IUGR and SGA fetuses were defined as fetuses whose estimated fetal weight (EFW) was below 10th percentile for gestational age with and without umbilical artery (UA) Doppler abnormalities, respectively. Fetal aorta intima media thickness (aIMT) was evaluated by ultrasound in the same fetal groups. Data were analyzed by R (version 2.15.2). Results. There were 37 IUGR mother-child couples, 33 SGA, and 70 AGA. Leptin, TNFα, IL-6, and CRP serum levels were higher in IUGR pregnant patients (P < 0.05). Adiponectin levels were significantly reduced in IUGR fetuses compared to SGA and AGA, while leptin, TNFα, and IL-6 levels were higher in IUGR group (P ≤ 0.05). Fetal aIMT was significantly higher in IUGR (P < 0.05) and in this group there was a negative correlation between aIMT and adiponectin/leptin ratio (A/L ratio) (P < 0.05) and between adiponectin and IL-6 levels (P < 0.05). Conclusions. In conclusion, compared to SGA and AGA, IUGR fetuses had reduced circulating levels of adiponectin and elevated measures of aIMT and several inflammatory markers. Moreover, adiponectin levels were negatively correlated with aIMT in IUGR fetuses suggesting a possible causal link between reduced adiponectin and vessel remodelling.

Desaturase activities and metabolic control in type 2 diabetes

The aim of this study was to elucidate the effects of a poor glycemic control on fatty acid composition and desaturase activities in type 2 diabetic patients. Plasma phospholipid fatty acid composition and desaturase activities (estimated from fatty acid product to precursor ratios) were measured in 30 type 2 diabetic patients during poor metabolic control and after achieving a good metabolic control. Significant changes were recorded in the percentages of palmitic, stearic, dihomo-gamma-linolenic, docosatetraenoic and docosapentaenoic acid. The delta-5 desaturase activity was significantly higher with poor than with good metabolic control. The changes identified in plasma phospholipid fatty acid composition and the desaturase activity in type 2 diabetic patients go in the opposite direction to those described in similar conditions in type 1 diabetic patients and may be relevant to a better understanding of the role of metabolic control in the progression of chronic complications in type 2 diabetic patients.

Activation of the Dopamine Receptor Type-2 (DRD2) Promoter by 9-Cis Retinoic Acid in a Cellular Model of Cushing's Disease Mediates the Inhibition of Cell Proliferation and ACTH Secretion Without a Complete Corticotroph-to-Melanotroph Transdifferentiation

Cushings disease (CD) is a rare condition in which hypercortisolemia is secondary to excessive ACTH release from a pituitary corticotroph adenoma. CD is associated with significant morbidity and mortality, and a safe therapy that effectively targets the pituitary tumor is still lacking. Retinoic acid (RA) and dopamine agonists (DAs) have recently been considered as monotherapy in CD patients, and satisfactory results have been reported, albeit in a limited number of patients. Given the permissive role of RA on the dopamine receptor type-2 (DRD2), the aim of the present study was to see whether a combination of 9-cis RA and the DA bromocriptine (Br) might represent a possible treatment for CD. Here we show that 9-cis RA induces a functional DRD2 in the pituitary corticotroph cell line AtT20, and increases cell sensitivity to Br via a mechanism only partially related to corticotroph-to-melanotroph transdifferentiation. In addition, 9-cis RA and Br act synergistically to modulate cell viability, with favorable implications for clinical use. In nearly 45% of corticotropinoma-derived primary cultures, the combined administration of 9-cis RA and Br lowered the steady-state level of the ACTH precursor proopiomelanocortin (POMC) more efficiently than either of the drugs alone. In conclusion, the effects of a combination of 9-cis RA and Br on ACTH synthesis/secretion and cell viability in AtT20, and on POMC transcriptional activity in human corticotropinomas might represent a suitable starting point for assessing the potential of this treatment regimen for ACTH-secreting pituitary adenomas. This study thus has potentially important implications for novel therapeutic approaches to CD.

Nonenzymatically Glycated Lipoprotein ApoA‐I in Plasma of Diabetic and Nephropathic Patients

ApoA‐I, which constitutes 70% of the apolipoprotein content of high‐density lipoproteins, acts as an acceptor for the transfer of phospholipids and free cholesterol from peripheral tissues and transports cholesterol in the liver and other tissue for excretion and steroidogenesis. In order to verify its possible structural alteration in pathological states, plasma samples from healthy, diabetic, and nephropathic subjects have been analyzed by two‐dimensional gel electrophoresis. By this approach, clear differences among the three classes of subjects become evident and, in the case of diabetic and nephropathic patients, intense spots are present. The matrix‐assisted laser desorption/ionization mass spectrometry analysis of their digestion products shows that an overexpression of unglycated and glycated ApoA‐I is present in both pathological states, reasonably affecting the efficiency in cholesterol transport.

Pregnancy outcome in immigrant women with gestational diabetes mellitus

Recent studies show adverse outcomes of pregnancy among immigrant women from countries with high diabetes rates. We compared maternal and fetal outcomes in immigrant and Italian women with gestational diabetes mellitus (GDM) followed up at our center. Maternal characteristics considered were age, pre-pregnancy body mass index (BMI), HbA1c, frequency of insulin treatment, timing and mode of delivery, and hypertensive disorders; and, for fetal outcome, infants large or small for gestational age, and fetal complications. Pre-pregnancy BMI and HbA1c were higher in immigrant GDM women than in Italians, and more of them were on insulin. No differences in maternal outcome emerged between the two groups. More large for gestational age (LGA) babies were born to immigrant women than to Italians, but no other differences emerged. Apart from newborn LGA, maternal and fetal outcomes were comparable in our immigrant and Italian GDM women. Immigrant GDM women have favourable outcomes if given access to health care and language and cultural barriers are removed.

Urinary peptides as a diagnostic tool for renal failure detected by matrix-assisted laser desorption/ionisation mass spectrometry: an evaluation of their clinical significance

The development of new analytical methodologies related to the proteome for the evaluation of renal physiology and pathology is surely of wide interest for physicians, giving them new tools for monitoring complications associated with diabetes, such as end-stage renal disease. In the present study, the clinical significance of the urinary abundance of two peptides, SGSVIDQSRVLNLGPITR (the uromodulin precursor, m/z 1912) and IGPHypGPHypGLMGPP [present in the collagen-α-5(IV) chain precursor, m/z 1219], detected by matrix-assisted laser desorption/ionisation mass spectrometry (MALDI/MS) in microalbuminuric or nephropathic diabetic patients and in non-diabetic nephropathic patients was evaluated. A progressive increase in the abundance of the ion at m/z 1219 and a decrease in the abundance of the ion at m/z 1912 have been found in diabetic microalbuminuric, diabetic–nephropathic and nephropathic patients. Linear correlations are present between serum creatinine values and the abundances of the ions at m/z 1219 (positive correlation, r = 0.3645, P < 0.0001) and at m/z 1912 (negative correlation, r = −0.3053, P < 0.0005). Correlations between the MALDI data and the estimated glomerular filtration rate were also found, while relationships with urinary albumin excretion were found only in sub-sets of patients. Analysis of receiver operating characteristic curves showed a sensitivity up to 96% and a specificity of up to 84% for the two ionic species, or their ratio, for distinguishing diabetic patients with different degrees of nephropathy from healthy subjects, proving that the urinary abundance of the two peptides at m/z 1219 and m/z 1912, determined with MALDI/MS, may be considered as a possible diagnostic tool for the determination of progression toward renal failure, also with the aim of monitoring kidney function, in diabetic patients.