Improved angiogenic activity of endothelial progenitor cell in diabetic patients treated with insulin plus metformin.

Type 2 diabetes (T2DM) is associated with an increased vascular disease. Moreover, endothelial progenitor cell (EPC) function is impaired in diabetic patients. Decreased EPC number plays a critical role in reduced endothelial repair and development of the vascular disorder. To determine the effect of metformin and insulin plus metformin on functional activity of EPCs, 130 participants were divided into three groups (group 1: healthy control; group 2: metformin; group 3: insulin plus metformin). The concentration of EPCs in the circulation was first quantified. Thereafter, circulating EPCs (cEPCs) were harvested and the biological features of these cells including proliferative, clonogenicity, tubulogenic, and migratory properties were analyzed after expansion. The serum protein levels of some proangiogenic factors were also measured. Our results showed greater numbers of cEPCs in control and in diabetic patients treated with insulin plus metformin than in metformin-treated patients. Insulin plus metformin therapy was associated with augmented proliferative, clonogenicity, migratory, and tubulogenic activity of cEPCs in patients with T2DM. Increased serum concentrations of angiogenic factors were also observed in patients treated with insulin plus metformin. Western blot analysis showed increased protein levels of pTie-2/Tie2 and Pakt/AKT in cEPCs harvested from T2DM, treated with insulin metformin plus. This study showed that treatment with insulin plus metformin in diabetic patients is associated with increased mobilization of EPCs into the circulation, with potential beneficial effect in vascular protection in diabetic patients.

Increased circulation mobilization of endothelial progenitor cells in preterm infants with retinopathy of prematurity.

Retinopathy of prematurity (ROP) is a result of increased pathological neoangiogenesis of the retina in preterm infants. Cells responsible for the pathogenesis of ROP are unclear, but some evidence indicates that bone marrow derived cells are involved in this disorder. Endothelial progenitor cells (EPCs), play a role in angiogenesis in response to tissue ischemia or endothelial damage. In this study, the number of cEPCs in preterm infants with ROP was determined to identify whether the circulation mobilization of EPCs is associated with ROP. We evaluated 99 participants in this study: 22 preterm infants with ROP, 35 preterm infants without ROP, and 42 full-term infants. The release of EPCs in the circulation was first quantified. Thereafter, cEPCs were harvested and cultivated, then the biological features of these cells including migratory, proliferative, and tubulogenic activities were analyzed. The mRNA levels of some proangiogenic factors were also measured in preterm infants. Our results showed greater numbers of cEPCs in infants with ROP, which was associated with increased serum concentrations of angiogenic factors and with augmented proliferative, migratory, and tubulogenic activity of these cells. Western blotting showed increased protein levels of VEGF and HIF-α in cEPCs harvested from ROP infants. This study showed that ROP in preterm infants is associated with increased mobilization of EPCs into the circulation. Therefore, increased cEPCs along with elevated levels of angiogenic factors and tubulogenesis suggest that these cells may play a role in the development and progression of ROP.

Taq1B Polymorphism of Cholesteryl Ester Transfer Protein (CETP) and Its Effects on the Serum Lipid Levels in Metabolic Syndrome Patients.

The metabolic syndrome (MetS) is one of the most important risk factors for type 2 diabetes and cardiovascular disease. This syndrome is characterized by abdominal obesity, hypertension, insulin resistance, and dyslipidemia. The plasma origin of Cholesteryl ester transfer protein (CETP) is responsible for transferring cholesterol esters from high-density lipoprotein particles to apolipoprotein B containing lipoproteins compartment. We conducted this study to investigate the association between CETP gene Taq1B (rs708272) polymorphism in the metabolic syndrome among Iranian subjects. A sample size of 200 patients diagnosed with MetS together with 200 healthy donors as control were enrolled in this study. The investigation of polymorphism was performed by the use of polymerase chain reaction and restriction fragment length polymorphism analysis. To determine the relationship between polymorphism and lipid profile, we measured lipids and CETP concentration in metabolic syndrome and control subjects. Genotype distribution and allelic frequencies of polymorphism were determined and compared in both groups. Our findings showed that all clinical and biochemical characteristics in patients differed from the control group. The results showed that genotype and allele frequency of the Taq1B polymorphism was not significantly different between two groups. Instinctively, CETP was significantly higher in metabolic syndrome (1.64 ± 0.32 µg/ml) than in control (1.53 ± 0.34 µg/ml). A low level of CETP was found in blood of B2B2 typified genotype. In spite of Taq1B polymorphism on ester transfer protein concentration, no direct correlation was found between this polymorphism and metabolic syndrome.