Regulatory mechanisms of the early phase of white adipocyte differentiation: an overview.

The adipose organ comprises two main fat depots termed white and brown adipose tissues. Adipogenesis is a process leading to newly differentiated adipocytes starting from precursor cells, which requires the contribution of many cellular activities at the genome, transcriptome, proteome, and metabolome levels. The adipogenic program is accomplished through two sequential phases; the first includes events favoring the commitment of adipose tissue stem cells/precursors to preadipocytes, while the second involves mechanisms that allow the achievement of full adipocyte differentiation. While there is a very large literature about the mechanisms involved in terminal adipogenesis, little is known about the first stage of this process. Growing interest in this field is due to the recent identification of adipose tissue precursors, which include a heterogenous cell population within different types of adipose tissue as well as within the same fat depot. In addition, the alteration of the heterogeneity of adipose tissue stem cells and of the mechanisms involved in their commitment have been linked to adipose tissue development defects and hence to the onset/progression of metabolic diseases, such as obesity. For this reason, the characterization of early adipogenic events is crucial to understand the etiology and the evolution of adipogenesis-related pathologies, and to explore the adipose tissue precursors' potential as future tools for precision medicine.

MTHFR, TS and XRCC1 genetic variants may affect survival in patients with myelodysplastic syndromes treated with supportive care or azacitidine.

We evaluated the impact of genomic polymorphisms in folate-metabolizing, DNA synthesis and DNA repair enzymes on the clinical outcome of 108 patients with myelodysplastic syndromes (MDS) receiving best supportive care (BSC) or azacitidine. A statistically significant association between methylenetetrahydrofolate reductase (MTHFR) 677T/T, thymidylate synthase (TS) 5'-untranslated region (UTR) 3RG, TS 3'-UTR -6 bp/-6 bp, XRCC1 399G/G genotypes and short survival was found in patients receiving BSC by multivariate analysis (P<0.001; P=0.026; P=0.058; P=0.024). MTHFR 677T/T, TS 3'-UTR -6 bp/-6 bp and XRCC1 399G/G genotypes were associated with short survival in patients receiving azacitidine by multivariate analysis (P<0.001; P=0.004; P=0.002). We then performed an exploratory analysis to evaluate the effect of the simultaneous presence of multiple adverse variant genotypes. Interestingly, patients with ⩾1 adverse genetic variants had a short survival, independently from their International Prognostic Scoring System (IPSS) and therapy received. To our knowledge, this is the first study showing that polymorphisms in folate-metabolizing pathway, DNA synthesis and DNA repair genes could influence survival of MDS patients.

Attenuation of diet-induced obesity and induction of white fat browning with a chemical inhibitor of histone deacetylases.

BACKGROUND/OBJECTIVES: In the last decade, a strict link between epigenetics and metabolism has been demonstrated. Histone deacetylases (HDACs) have emerged as key epigenetic regulators involved in metabolic homeostasis in normal and pathologic conditions. Here we investigated the effect of the class I HDAC inhibitor MS-275 in a model of obesity induced by a high-fat diet (HFD). METHODS: C57BL6/J male mice were fed HFD for 17 weeks and then randomized in two groups, treated intraperitoneally with vehicle dimethylsulfoxide (DMSO) or with the class I selective HDAC inhibitor MS-275 every other day for 22 days. Glucose tolerance test and measurement of body temperature during cold exposure were performed. Adipose tissues and liver were phenotypically characterized through histological analysis. Gene and protein expression analysis of brown and white adipose tissues (WATs) were performed. RESULTS: MS-275 treated mice showed 10% reduction of body weight, lower adipocyte size and improved glucose tolerance. Inhibition of class I HDAC determined reduction of adipocyte size and of fat mass, paralleled by higher expression of adipose functionality markers and by increased rate of lipolysis and fatty acid ß-oxidation. MS-275 also promoted thermogenic capacity, related to 'browning' of visceral and subcutaneous WAT, showing increased expression of uncoupling protein 1. In brown adipose tissue, we observed limited effects on gene expression and only reduction of brown adipocyte size. CONCLUSIONS: This study provides evidence that class I HDAC inhibition stimulated functionality and oxidative potential of adipose tissue, improving glucose tolerance and ameliorating the metabolic profile in diet-induced obese mice.

Bone Marrow Microenvironment Involvement in t-MN: Focus on Mesenchymal Stem Cells.

Therapy-related myeloid neoplasms (t-MN) are a late complication of cytotoxic therapy (CT) used in the treatment of both malignant and non-malignant diseases. Historically, t-MN has been considered to be a direct consequence of DNA damage induced in normal hematopoietic stem or progenitor cells (HSPC) by CT. However, we now know that treatment-induced mutations in HSC are not the only players involved in t-MN development, but additional factors may contribute to the onset of t-MN. One of the known drivers involved in this field is the bone marrow microenvironment (BMM) and, in particular, bone marrow mesenchymal stem cells (BM-MSC), whose role in t-MN pathogenesis is the topic of this mini-review. BM-MSCs, physiologically, support HSC maintenance, self-renewal, and differentiation through hematopoietic-stromal interactions and the production of cytokines. In addition, BM-MSCs maintain the stability of the BM immune microenvironment and reduce the damage caused to HSC by stress stimuli. In the t-MN context, chemo/radiotherapy may induce damage to the BM-MSC and likewise alter BM-MSC functions by promoting pro-inflammatory response, clonal selection and/or the production of factors that may favor malignant hematopoiesis. Over the last decade, it has been shown that BM-MSC isolated from patients with de novo and therapy-related MN exhibit decreased proliferative and clonogenic capacity, altered morphology, increased senescence, defective osteogenic differentiation potential, impaired immune-regulatory properties, and reduced ability to support HSC growth and differentiation, as compared to normal BM-MSC. Although the understanding of the genetic and gene expression profile associated with ex vivo-expanded t-MN-MSCs remains limited and debatable, its potential role in prognostic and therapeutic terms is acting as a flywheel of attraction for many researchers.

Expression profiling of extramedullary acute myeloid leukemia suggests involvement of epithelial-mesenchymal transition pathways.

Extramedullary (EM) colonization is a rare complication of acute myeloid leukemia (AML), occurring in about 10% of patients, but the processes underlying tissue invasion are not entirely characterized. Through the application of RNAseq technology, we examined the transcriptome profile of 13 AMLs, 9 of whom presented an EM localization. Our analysis revealed significant deregulation within the extracellular matrix (ECM)-receptor interaction and focal-adhesion pathways, specifically in the EM sites. The transcription factor TWIST1, which is known to impact on cancer invasion by dysregulating epithelial-mesenchymal-transition (EMT) processes, was significantly upregulated in EM-AML. To test the functional impact of TWIST1 overexpression, we treated OCI-AML3s with TWIST1-siRNA or metformin, a drug known to inhibit tumor progression in cancer models. After 48 h, we showed downregulation of TWIST1, and of the EMT-related genes FN1 and SNAI2. This was associated with significant impairment of migration and invasion processes by Boyden chamber assays. Our study shed light on the molecular mechanisms associated with EM tissue invasion in AML, and on the ability of metformin to interfere with key players of this process. TWIST1 may configure as candidate marker of EM-AML progression, and inhibition of EMT-pathways may represent an innovative therapeutic intervention to prevent or treat this complication.

Absence of FGFR3-TACC3 rearrangement in hematological malignancies with numerical chromosomal alteration.

FGFR-TACC, found in different tumor types, is characterized by the fusion of a member of fibroblast grown factor receptor (FGFR) tyrosine kinase (TK) family to a member of the transforming acidic coiled-coil (TACC) proteins. Because chromosome numerical alterations, hallmarks of FGFR-TACC fusions are present in many hematological disorders and there are no data on the prevalence, we studied a series of patients with acute myeloid leukemia and myelodysplastic syndrome who presented numerical alterations using cytogenetic traditional analysis. None of the analyzed samples showed FGFR3-TACC3 gene fusion, so screening for this mutation at diagnosis is not recommended.

Dynamics of apomyoglobin in the alpha-to-beta transition and of partially unfolded aggregated protein.

Changes of molecular dynamics in the alpha-to-beta transition associated with amyloid fibril formation were explored on apomyoglobin (ApoMb) as a model system. Circular dichroism, neutron and X-ray scattering experiments were performed as a function of temperature on the protein, at different solvent conditions. A significant change in molecular dynamics was observed at the alpha-to-beta transition at about 55 degrees C, indicating a more resilient high temperature beta structure phase. A similar effect at approximately the same temperature was observed in holo-myoglobin, associated with partial unfolding and protein aggregation. A study in a wide temperature range between 20 and 360 K revealed that a dynamical transition at about 200 K for motions in the 50 ps time scale exists also for a hydrated powder of heat-denatured aggregated ApoMb.

Neutron scattering study of the vibrations in vitreous silica and germania.

The incoherent approximation for the determination of the vibrational density of states of glasses from inelastic neutron or x-ray scattering data is extended to treat the coherent scattering. The method is applied to new room temperature measurements of vitreous silica and germania on the thermal time-of-flight spectrometer IN4 at the High Flux Reactor in Grenoble. The inelastic dynamic structure factor at the boson peak turns out to agree reasonably well with simulation results, but the long-wavelength fraction exceeds the expectation of the Debye model, in particular, in germania.

Plasma lipoproteins and cholesterol metabolism in Yoshida rats: an animal model of spontaneous hyperlipemia.

The purpose of this study was to characterize the lipoprotein profile and cholesterol metabolism in Yoshida rats, a strain of inbred genetically hyperlipemic animals. For comparison, Brown Norway rats were used as control animals. Plasma cholesterol and triglycerides were higher in Yoshida as compared to Brown Norway, the elevation of cholesterol being due to a rise in HDL fraction. Triglyceride distribution among lipoproteins showed an increase in VLDL fraction. Hyperlipemia was not related to diabetes, hypothyroidism or nephropathy. Plasma triglycerides production was increased in Yoshida rats, while lipoprotein and hepatic lipases were similar in the two groups. Hypercholesterolemia was associated with a defect of lipoprotein receptor activity and with elevated HMG-CoA reductase and cholesterol 7 alpha - hydroxylase; conversely ACAT activity was lower in Yoshida as compared to Brown Norway rats. Sterol fecal excretion was comparable in the two groups and hypercholesterolemia in Yoshida rats was not associated to an increase of cholesterol saturation of the bile. We suggest that lipoprotein overproduction is the main cause for hyperlipidemia in this strain of rats.

Effect of natural and structurally modified bile acids on cholesterol metabolizing enzymes in rat liver microsomes. II.

The effect of ursodeoxycholic acid analogues bearing modifications at the side-chain moiety of the molecule was tested on cholesterol 7 alpha-hydroxylase and HMG-CoA reductase in rat liver microsomes. The compounds included 23 R,S mixture and the single isomers 23R and 23S of 23 methylursodeoxycholic acid (23-methyl UDCA), the isomeric mixture (cis + trans) of 3 alpha,7 beta-dihydroxy-20,22-methylen-5 beta-cholan-23-oic acid (norcypro-UDCA) and the corresponding single isomers. Each steroid was added to liver microsomes as the sodium salt, at concentrations ranging from 25 to 200 microM. Isomers 23R and 23S of 23-methyl-UDCA inhibited cholesterol 7 alpha-hydroxylase in a concentration-dependent manner. The inhibitory capacity was similar for the two isomers. The extent of inhibition of the analogues was greater than that of the parent compound UDCA. Shortening of the side-chain in norcypro-UDCA resulted in a partial loss of the inhibitory effect, as compared to cypro-UDCA (3 alpha,7 beta-dihydroxy-22,23-methylen-5 beta-cholan-24-oic acid). None of these bile acid derivatives affected the activity of the enzyme HMG-CoA reductase.

Effect of natural and structurally modified bile acids on cholesterol metabolizing enzymes in rat liver microsomes.

The effect of chenodeoxycholic (CDCA), ursodeoxycholic (UDCA), tauroursodeoxycholic (TUDCA), cholic (CA), ursocholic (UCA) acids, analogues of CDCA and UDCA with a cyclopropyl ring at C22, C23 (cypro-CDCA and cypro-UDCA) and 23-methylursodeoxycholic acid (MUDCA) on cholesterol 7 alpha-hydroxylase was studied in rat liver microsomes. Cypro-analogues consisted of a mixture of four diasteroisomers, while MUDCA was the racemic mixture of two enantiomers. Each steroid was added to liver microsomes at concentrations ranging from 10 to 200 microM. With the exception of UCA and CA, all the bile acids inhibited cholesterol 7 alpha-hydroxylase activity. The inhibition shown by cypro-CDCA and cypro-UDCA was stronger than that observed with the corresponding natural compounds. 22S,23S cypro-UDCA exhibited an inhibitory effect which was more pronounced than that of the diasteroisomer mixture. The isomer 22R,23S was less effective and decreased cholesterol 7 alpha-hydroxylase activity in a manner comparable to that of UDCA. The effect of CDCA, UDCA and the cyclopropyl analogues was also tested with respect to HMG-CoA reductase and acylCoA cholesterol acyltransferase (ACAT) activities. ACAT was stimulated by the isomer 22S,23S cypro-UDCA but not affected by the other bile acids. No effect was observed as regards HMG-CoA reductase.

The serum IgA class anti-tissue transglutaminase antibodies in the diagnosis and follow up of coeliac disease. Results of an international multi-centre study. International Working Group on Eu-tTG.

OBJECTIVES: So far the reliability of the anti-tissue transglutaminase (anti-tTG) test for the diagnosis of coeliac disease has mostly been evaluated using slightly different enzyme-linked immunosorbent assays (ELISAs) in selected and usually small groups of patients. The aims of this study were: (1) to evaluate the reliability of the IgA anti-tTG antibodies for the diagnosis of coeliac disease; and (2) to define the sensitivity and specificity of a commercially available kit for the anti-tTG antibodies' quantitative determination. DESIGN: Each centre in this international multi-centre study collected sera from three groups of subjects: coeliac disease patients at the onset of (1) or on a gluten-free diet for at least 12 months (2); disease and healthy controls (3). METHODS: The anti-tTG antibodies were determined in duplicate using an ELISA-based commercially available kit (Eu-tTG Eurospital, Trieste, Italy). RESULTS: The following overall cases and controls have been enrolled: (1) 399 subjects with active coeliac disease; (2) 351 treated coeliac disease cases; (3) 432 controls. The centralized re-testing was performed on: (1) group a: 176 patients with active coeliac disease (mean anti-tTG, 21 arbitrary units [AU]); (2) group b: 172 treated coeliac disease cases (mean anti-tTG, 5 AU); (3) group c: 206 controls (mean anti-tTG, 3 AU). In active coeliacs, the anti-tTG antibodies showed a significant progressive decrease with age, while in controls an opposite trend was found. In active coeliac disease patients, the anti-tTG antibodies were significantly higher in coeliacs with a grade III enteropathy than in those showing a grade II lesion. In treated coeliacs, the mean anti-tTG values were significantly lower in patients strictly adhering to a gluten-free diet than in those reporting dietary transgressions. The sensitivity and the specificity of the Eu-tTG assay were 90% and 96%, respectively. CONCLUSION: The results of this study show that the commercially available test for the anti-tTG antibodies' determination is a reproducible and valuable tool for the diagnosis and follow up of coeliac disease.

Anti-human versus anti-guinea pig tissue transglutaminase antibodies as the first-level serological screening test for coeliac disease in the general population.

BACKGROUND: So far the reliability of the anti-guinea pig and anti-human tissue transglutaminase antibodies for the coeliac disease diagnosis has been evaluated in selected groups of patients. AIM: To compare the diagnostic accuracy of anti-human versus anti-guinea pig tissue transglutaminase in the coeliac disease screening of the general population. SUBJECTS: Two healthy Italian populations living in Marche region and in Western Sardinia. METHODS: Both anti-guinea pig and anti-human tissue transglutaminase were determined using an enzyme-linked immunosorbent assay-based commercially available kit (Eu-tTG, Eurospital, Trieste, Italy). RESULTS: During the period 1999-2001, 3541 subjects (1500 from "continental" Italy and 2041 from Sardinia) were screened for coeliac disease using both anti-guinea pig and anti-human tissue transglutaminase as first-level tests. Both these tests were negative in 3439/3541 sera, while 29 resulted positive for both of them and 73 showed discordant results. Overall, 50 intestinal biopsies were performed in 22, 21 and 7 subjects with positivity to both screening tests, to anti-guinea pig and to anti-human tissue transglutaminase alone, respectively. A coeliac disease diagnosis was made in 25 subjects giving an overall prevalence of 1:126 individuals. The anti-tissue transglutaminase specificity and sensitivity were 98 and 92% for guinea pig and 99.6 and 96% for human tissue transglutaminase, respectively. CONCLUSIONS: The anti-human tissue transglutaminase test should definitely replace the anti-guinea pig-derived one as first-level screening tool for identifying all subjects who need the second-level investigations (small intestinal biopsy).

Dietary compliance in screening-detected coeliac disease adolescents.

In 1992-94 we screened 6315 students for coeliac disease (CD) by testing antigliadin antibodies (AGA) as the first-level investigation. We found 28 biopsy-proven coeliac patients who were invited to start the gluten-free diet (GFD). The aim of this study was a clinical and laboratory follow-up in these screening-detected coeliac adolescents. Patients were 17 females and 11 males with a mean age at diagnosis of 12.8 +/- 1 years (range 11-4). Mean follow-up duration time was 23 +/- 7 months (range 9-37). Twenty-three of the 28 screening-detected coeliac patients came to the control visit, 3 refused the follow-up and 2 subjects were not found. Twelve patients (52.2%) stated that they never ate any gluten-containing food, while 11 of them (47.8%) reported occasional transgressions to the diet. GFD acceptance was reported as good (n = 6), moderate (n = 11) or low (n = 6). After starting the GFD, signs of improvement were seen in most patients, such as weight gain, increased height velocity and increased feeling of well-being. AGA (both IgG and IgA classes) and antiendomysium antibodies (AEA) were normal in 19 subjects, 2 cases had IgG-AGA and AEA positivity, 1 patient showed abnormal AGA and AEA levels, while isolated IgA-AGA positivity persisted in 1 case. This study shows that even silent CD cases can clinically benefit from the GFD. The consequences of occasional transgressions to the GFD remain unclear.

The coeliac iceberg in Italy. A multicentre antigliadin antibodies screening for coeliac disease in school-age subjects.

BACKGROUND: Recent studies suggest that coeliac disease (CD) is one of the commonest, life-long disorders in Italy. The aims of this multicentre work were: (a) to establish the prevalence of CD on a nationwide basis; and (b) to characterize the CD clinical spectrum in Italy. PATIENTS AND METHODS: Fifteen centres screened 17,201 students aged 6-15 years (68.6% of the eligible population) by the combined determination of serum IgG- and IgA-antigliadin antibody (AGA) test; 1289 (7.5%) were IgG and/or IgA-AGA positive and were recalled for the second-level investigation; 111 of them met the criteria for the intestinal biopsy: IgA-AGA positivity and/or AEA positivity or IgG-AGA positivity plus serum IgA deficiency. RESULTS: Intestinal biopsy was performed on 98 of the 111 subjects. CD was diagnosed in 82 subjects (75 biopsy proven, 7 not biopsied but with associated AGA and AEA positivity). Most of the screening-detected coeliac patients showed low-grade intensity illness often associated with decreased psychophysical well-being. There were two AEA negative cases with associated CD and IgA deficiency. The prevalence of undiagnosed CD was 4.77 x 1000 (95% CI 3.79-5.91), 1 in 210 subjects. The overall prevalence of CD, including known CD cases, was 5.44 x 1000 (95% CI 4.57-6.44), 1 in 184 subjects. The ratio of known to undiagnosed CD cases was 1 in 7. CONCLUSIONS: These findings confirm that, in Italy, CD is one of the most common chronic disorders showing a wide and heterogeneous clinical spectrum. Most CD cases remain undiagnosed unless actively searched.

[High prevalence of hepatitis C virus infection in patients with non-Hodgkin's lymphoma at the onset. Preliminary results of an Italian multicenter study]. / Elevata frequenza della infezione da virus dell'epatite C nei pazienti con linfoma non-Hodgkin all'esordio. Risultati preliminari di uno studio multicentrico italiano.

143 patients with non-Hodgkin lymphoma (NHL) at the onset entered this perspective study on NHL-associated risk factors. They were 87 males and 56 females with a mean age of 52.3 years (range 14.6-82.3). An associated hepatitis C virus (HCV) infection was found in 16 of the 143 NHL cases (11.2%; 95% CI 6.5-17.5). They were 11 males and 5 females [mean age 59.9] year with disseminated (13/16) or localized NHL disease (3/16)]. The NHL histological subgroup was low grade (6/16), intermediate grade (2/16) or high grade (8/16). The cell origin was B in 15/16 cases and B cell-T cell rich in 1/16. The discovery of HCV infection was contemporary to lymphoma diagnosis in 6/16 cases but preceded the NHL onset in the other 10 patients. In these 10 patients the median time between HCV infection diagnosis and NHL onset was 3.6 years (range 1-14.5). These data confirm that in Italy the prevalence of HCV infection in patients with NHL (11.2%) is significantly higher than expected in the general population (1.3-3.2%). The finding that, in most cases, HCV infection was definitely antecedent to NHL onset, usually by years, adds evidence to the possible causative role of the HCV in lymphomagenesis.

[Protein-losing gastroenteropathy (Ménétrier's disease) in childhood: a report of 3 cases]. / Gastroenteropatia protido-disperdente (malattia di Ménétrier) nell'età pediatrica: descrizione di tre casi.

So far, Ménétrier's disease has been thought to be an uncommon disorder in children. It is characterized by hypertrophic gastritis, protein-losing enteropathy, hypoproteinemia and edema. During childhood, the main features of this condition include an abrupt onset and a spontaneous recovery. In this paper we describe three children, aging between 3 months and 3 years, who presented with protracted vomiting, generalized edema, colitis (one case) and elevated serum aminotransferases (one case). The diagnosis of Ménétrier's disease was made by finding the typical endoscopic and histological picture of the gastric mucosa (two cases) or by the radiological findings (one case). The fecal alpha-1-antitrypsin excretion, which is a marker of the protein-losing enteropathy, was high in all patients. Two cases showed evidences for a primary CMV infection as the possible cause of Ménétrier's disease, due to the presence of cytomegalic inclusions in the gastric mucosa and the IgM class anti-CMV antibodies positivity. All 3 cases, who received only a support treatment (plasma and albumin intravenous infusions), completely recovered in a 2-3 weeks time. In conclusion, it is confirmed that in children a protein-losing gastroenteropathy may be caused by a primary infection with CMV.

Total thyroidectomy for Graves' disease treatment.

OBJECTIVES: Graves' disease (GD) is the most common cause of hyperthyroidism, and accounts worldwide for 60-80% of all cases. The diagnosis is based on clinical findings, and is confirmed by the presence of TRAB, suppression of TSH, and elevation of free thyroxin (free T4), and triiodinethyronin (free T3). GD can be treated by antithyroid drugs, radioactive iodine, or surgery. The aim of this study was to review retrospectively the surgical management, in terms of safety and efficacy, in 50 patients operated in the Department of Surgical Sciences since 2005 through 2010 and followed up at the Endocrinology Unit A of the Experimental Medicine Department. We assessed postoperative complications, which included the presence, persistence and development of ophthalmopathy, transient hypocalcemia, permanent hypoparathyroidism and recurrent laryngeal nerve palsy. MATERIALS AND METHODS: We analyzed data from 50 patients with GD who were eligible and underwent Total Thyroidectomy (TT). Thirty-nine patients underwent TT for recurrent hyperthyroidism after medical therapy and eleven patients for severe ophtalmopathy. The mean follow up was 41 months (range: 10-70). RESULTS: Eleven patients had ophtalmopathy before surgery. Four patients developed an ophtalmopathy after surgery. Eleven patients presented hypocalcemia, transient in ten patients and permanent in one patient. Five patients developed a transient disphony. Conclusions. Total thyroidectomy is a safe and radical procedure in Graves' disease treatment. Complications of TT are not different than subtotal thyroidectomy if it's performed by expert surgeons.

5-azacytidine in chronic myelomonocytic leukemia: case report and review of literature.

Hypomethylating drugs are useful in the management of Myelodysplastic syndromes, but there are only few reports on chronic myelomonocycitic (CMML) leukemia patients. We describe our experience in 3 CMML patients treated with azacitidine. Two patients obtained partial response after 4 treatment cycles with only minor toxicity and are in continuous partial response, with stable peripheral blood counts, at 29 and 30 cycles from treatment start.