Adriana A. Bosco

Differential effects of thalidomide on angiogenesis and tumor growth in mice.

Thalidomide, clinically used as an antiinflammatory and antitumoral drug, inhibited sponge-induced angiogenesis when administered systemically (100 mg/kg−1) in mice. However, it failed to inhibit solid Ehrlich tumor in the same mouse strain. We have used functional, biochemical and histological parameters to assess neovascularization and fibrovascular tissue infiltration of the mice sponge granuloma. The neovascularization growth as detected by development of blood flow and hemoglobin content extracted from the implants showed that thalidomide inhibited fibrovascular tissue formation by 40%. The functional and biochemical parameters correlated well with the histological study. Thalidomide had no inhibitory effect in the development of Ehrlich tumor. The detection of this selective action using the same animal strain bearing two different processes, supports the hypothesis that rather than species specificity, thalidomide is tissue specific. This approach may be used to identify the specificity of other therapeutic agents against distinct angiogenesis-dependent diseases.

Effect of acetylsalicylic acid on platelet activation and oxidative profile in a set of Brazilian patients with type 2 diabetes mellitus.

Type 2 diabetes mellitus (DM2) is a metabolic disorder associated with hyperactivation of platelets, increased formation of platelet microparticles (PMPs) and oxidative stress that are related to cardiovascular complications. Acetylsalicylic acid (ASA) is an antiplatelet agent used in the prevention of atherothrombosis. The aim of this study was to evaluate the effect of ASA by means of platelet activation and oxidative profile. We collected blood samples of 81 patients with DM2 before and during ASA treatment. These samples were analyzed to determine the levels of 2,3-dinor thromboxane-B2 (2,3-dinor-TXB2), PMPs, thiobarbituric acid reactive species (TBARS) and 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT). Moreover, the relationship between the levels of 2,3-dinor-TXB2 with some clinical and laboratory variables such as glycated hemoglobin, platelet count, D dimer, low-density lipoprotein cholesterol and glycoprotein IIb/IIIa and cyclooxygenase-1 polymorphisms was evaluated. ASA intake did not change the levels of PMP, TBARS and MTT. Although a significant decrease in the levels of 2,3 dinorTXB2 (P < 0.001) in patients under ASA has been observed, an equal and satisfactory response to this drug was not found. However, the presence of PIA2 allele in GPIIIa gene may be associated with a better response to ASA intake in these patients, whereas other clinical and laboratory variables showed no association with this drug use. These findings are consistent with previous reports in the literature that patients with DM2 do not benefit in an equal way from the use of ASA for primary prevention of atherothrombotic events.

Endocan: a new biomarker associated with inflammation in type 2 diabetes mellitus?

Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil

Annexin A1 concentrations is decreased in patients with diabetes type 2 and nephropathy

The diabetic nephropathy is considered an inflammatory process characterized by macrophage infiltration observed in every stage of renal involvement. In addition, pro-inflammatory cytokines and adhesion molecules are important in the development of the disease [1]. Annexin A1 (AnxA1) is a 37-kDa protein that regulates various cellular functions and binds to phospholipids in a calcium-dependent manner. Glucocorticoids (GC) regulate expression of ANXA1, which in turn mediates GCs anti-inflammatory actions; however, its expression is also contra-regulated by proinflammatory cytokines, as IL-6. AnxA1 presents anti-inflammatory properties, inhibiting distinct stages of the leukocyte transmigration cascade and interacting directly with NF-κB in an intracellular manner to reduce proinflammatory pathways [2]. AnxA1 has also proresolving properties including promotion of efferocytosis of apoptotic polymorphonuclear leucocytes and is widely present in soluble form in plasma. Some studies have suggested that AnxA1 deficiency may contribute to the etiology of inflammatory diseases [3,4]. We evaluated the AnxA1 concentrations in T2D patients with and without nephropathy and the correlation with IL-6 concentrations. We studied 4 T2D patients without nephropathy (mean age = 46 ± 12 years, 3 women) and 35 T2D patients with nephropathy (mean age = 56 ± 8 years, 31 women), recruited from Santa Casa Hospital (Belo Horizonte, Minas Gerais, Brazil) in the period of June 2012 to

IL-6, TNF-α, and IL-10 levels/polymorphisms and their association with type 2 diabetes mellitus and obesity in Brazilian individuals

OBJECTIVE This study aimed to investigate the association of plasma TNF-α, IL-6, and lL-10 levels and cytokine gene polymorphisms [TNF-α (-308 G→A), IL-6 (-174 C→G) and IL-10 (-1082 A→G, -819 T→C and -592 A→C)] in type 2 diabetes mellitus (T2DM) and obese patients. SUBJECTS AND METHODS One hundred and two T2DM patients and 62 controls were included in this study. Cytokine plasma levels were measured by the Cytometric Bead Array method. Genotyping was carried out by the polymerase chain reaction. RESULTS IL-6 levels were significantly different between T2DM patients and controls. Interestingly, IL-6 levels were higher in T2DM patients with BMI > 30 kg/m2 compared with other patients and obese controls. The genotype and allele frequencies were similar between patients and controls. In the T2DM group, the SNP IL-10 -819 T/C showed a difference between the cytokine level and genotypes: IL-10 level in the TT genotype was significantly higher when compared to CC genotype. CONCLUSIONS These results suggest an association between IL-6 levels and obesity, and IL-10 levels and the SNP -819 T/C in T2DM. Knowledge of these variants in T2DM might contribute to a better understanding of the role of inflammation in the etiology and progression of this disease.

Circulating microparticles levels are increased in patients with diabetic kidney disease: A case-control research

BACKGROUND Type 2 diabetes mellitus (T2DM) is associated with chronic lowgrade inflammation. Microparticles (MPs) are extracellular microvesicles released during apoptosis and cellular activation. The MPs pro-coagulant and pro-inflammatory activities are involved in endothelial dysfunction observed in T2DM patients. This study aimed to evaluate the circulating MPs profile in T2DM patients with diabetic kidney disease (DKD) and correlate it with clinical and laboratorial parameters. METHODS MPs derived from platelets (PMPs), leukocytes (LMPs), endothelial cells (EMPs), and expressing tissue factor (TFMPs) were measured by flow cytometry, in plasma of 39 DKD patients and 30 non-diabetic controls. RESULTS We observed higher PMPs, LMPs, EMPs, and TFMPs (all p<0.0001) levels in case group as compared to controls. For patients with DKD, circulating MPs levels were influenced by gender, but not by obesity status nor by T2DM onset. Fasting glucose and 25-hydroxyvitamin D levels showed correlation with circulating MPs levels in both groups. CONCLUSIONS These results suggest that type 2 diabetes mellitus patients with DKD presented higher circulating MPs levels - PMPs, LMPs, EMPs, and TFMPs - which correlated with metabolic alterations.

MMP-9 Levels and IMT of Carotid Arteries are Elevated in Obese Children and Adolescents Compared to Non-Obese

Background Childhood obesity is associated with increased risk of atherosclerosis and cardiovascular disease in adulthood. Increased intima-media thickness (IMT) of the carotid artery is linked to the initiation and progression of the chronic inflammatory processes implicated in cardiovascular disease. Matrix metalloproteinase-9 (MMP-9) plays an important role in the degradation of the extracellular matrix and, consequently, in the development, morphogenesis, repair and remodeling of connective tissues. Objectives (i) to determine and compare the concentrations of MMP-9, tissue inhibitor of metalloproteinase -1 (TIMP-1), and MMP-9/TIMP-1 ratio in obese and non-obese children and adolescents; (ii) to investigate the association of these markers with common and internal IMT of carotid arteries. Methods Cross-sectional study involving 32 obese and 32 non-obese (control) individuals between 8 - 18 years of age. Results Significantly (p < 0.05) higher values of MMP-9 concentration, as well as a higher MMP-9/TIMP-1 ratio were detected in the obese group compared to control counterparts. Common and internal carotid IMT values were significantly higher (p < 0.001) in the obese group compared to the control group. Positive correlations were observed between the common carotid IMT values and MMP-9 concentrations as well as MMP-9/TIMP-1 ratio. Conclusions Our data demonstrate that obese children and adolescents present higher mean IMT values, plasma MMP-9 and MMP-9/TIMP-1 ratio compared to the non-obese. Thus, these findings indicate that this group presents a risk profile for early atherosclerosis.

Visfatin levels are decreased in advanced stages of diabetic nephropathy

Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil, Santa Casa de Belo Horizonte, Belo Horizonte, Minas Gerais, Brazil, Colégio Técnico – COLTEC, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil, Instituto de Biociências, Universidade Estadual Paulista Júlio de Mesquita Filho, Botucatu, São Paulo, Brazil, and Faculdade de Farmácia, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil

Haptoglobin levels are influenced by Hp1–Hp2 polymorphism, obesity, inflammation, and hypertension in type 2 diabetes mellitus

BACKGROUND Type 2 diabetes mellitus (T2DM) is an inflammatory condition associated to obesity and increased oxidative stress. Haptoglobin (Hp) is an acute phase reactant that scavenges extracorpuscular hemoglobin from circulation and prevents heme-iron oxidative damage. OBJECTIVE To assess the association between Hp levels and Hp1-Hp2 gene polymorphism and clinical and laboratory parameters in patients with T2DM. METHODS The study sample consisted of 102 T2DM patients and 62 controls. Hp plasma levels were measured using an ELISA assay, and Hp genotyping was performed using a specific two-step allelic polymerase chain reaction. RESULTS Hp levels were higher in T2DM patients as compared to controls (p=0.005). T2DM patients with high blood pressure had higher Hp levels than patients without this comorbidity (p=0.021). Obese T2DM patients had higher Hp levels as compared to obese controls (p=0.009) and to non-obese T2DM patients (p=0.003). The Hp1-Hp1 genotype was showed to be associated to T2DM according to additive (OR=3.038, 95% CI 1.127-8.192; p=0.036) and dominant model (OR=0.320, 95% CI 0.118-0.839; p=0.010), but Hp2 allele carriers contributed with higher Hp levels in T2DM as compared to controls. Waist circumference (p=0.002), BMI (p=0.001), and IL-6 (p=0.012), and hs-CRP (p=0.001) levels positively correlated with Hp levels in the T2DM group. CONCLUSION These results suggest that Hp levels are influenced by Hp1-Hp2 polymorphism, obesity, inflammatory status, and high blood pressure in T2DM.

Proresolving protein Annexin A1: The role in type 2 diabetes mellitus and obesity

BACKGROUND Annexin A1 (AnxA1) is a protein involved in inflammation resolution that might be altered in obesity-associated type 2 diabetes mellitus (DM), which is a chronic inflammatory disease. The aim of this study was to evaluate AnxA1 serum levels in individuals with and without DM stratified according to the body mass index (BMI), and the dynamic of AnxA1 expression in adipose tissue from humans with obesity and non-obesity. METHODS Serum samples were obtained from 41 patients with DM (lean, overweight and obese) and 40 controls, and adipose tissue samples were obtained from 16 individuals with obesity (with or without DM), and 15 controls. RESULTS DM patients showed similar AnxA1 serum levels when compared to controls. However, when the individuals were stratified according to BMI, AnxA1 levels were higher in individuals with obesity than lean or overweight, and in overweight compared to lean individuals. Moreover, AnxA1 was correlated positively with IL-6 levels. AnxA1 levels were also positively correlated with BMI, waist circumference and waist-to-hip ratio. Furthermore, higher levels of cleaved AnxA1 were observed in adipose tissue from individuals with obesity, independently of DM status. CONCLUSIONS Enhanced levels of AnxA1 in serum of individuals with obesity suggest an attempt to counter-regulate the systemic inflammation process in this disease. However, the higher levels of cleaved AnxA1 in the adipose tissue of individuals with obesity could compromise its anti-inflammatory and proresolving actions, locally. Considering our data, AnxA1 cleavage in the adipose tissue, despite increased serum levels of this protein, and consequently the failure in inflammation resolution, suggests an important pathophysiological mechanism involved in inflammatory status observed in obesity.