Anastasios Kalofoutis

Inflammatory Process in Type 2 Diabetes

Abstract:  Population‐based studies have shown strong relationship between inflammatory markers and metabolic disturbances, obesity, and atherosclerosis, whereas inflammation has been considered as a “common soil” between these clinical entities and type 2 diabetes (T2D). The accumulation of macrophages in adipose tissue (AT), the common origin of macrophages and adipocytes, the prevalent presence of peripheral mononuclear cells, and apoptotic β cells by themselves seem to be the sources of inflammation present in T2D, since they generate the mediators of the inflammatory processes, namely cytokines. The main cytokines involved in the pathogenesis of T2D are interleukin‐1β (IL‐1β), with an action similar to the one present in type 1 diabetes, tumor necrosis factor‐α (TNF‐α), and IL‐6, considered as the main regulators of inflammation, leptin, more recently introduced, and several others, such as monocyte chemoattractant protein‐1, resistin, adiponectin, with either deleterious or beneficial effects in diabetic pathogenesis. The characterization of these molecules targeted diabetes treatment beyond the classical interventions with lifestyle changes and pharmaceutical agents, and toward the determination of specific molecular pathways that lead to low grade chronic inflammatory state mainly due to an immune systems unbalance.

Ankle-brachial index as a predictor of the extent of coronary atherosclerosis and cardiovascular events in patients with coronary artery disease

Resting ankle-brachial pressure index (ABI) is a noninvasive method to assess the patency of the lower extremity arterial system. This study aimed to examine the relation between ABI and the extent of coronary atherosclerosis, the extracoronary atherosclerosis lesions, and the prognosis of patients referred for elective coronary angiography. One hundred sixty-five consecutive patients underwent coronary angiography, ultrasound imaging for intima-media thickness measurement of carotid and femoral arteries and ABI evaluation; subjects were followed up for 14.5 +/- 2.4 months. With regard to vascular risk factors, only smoking (p = 0.025) and diabetes (p = 0.01) were related to ABI in the multiple regression analysis. ABI was independently and inversely related to carotid bifurcation (p = 0.0002) and common femoral artery intima-media thickness (p = 0.018). ABI was related to the extent of coronary artery disease as measured by number of coronary arteries diseased (analysis of variance, p = 0.04) and Gensini angiographic score (p = 0.01). In the follow-up study ABI < 0.90 was a univariate predictor of cardiovascular events (cardiac death, nonfatal myocardial infarction, unstable angina) and revascularization procedures. The estimated cumulative rate free of cardiovascular events was 90% for ABI > 0.90 and 73% for ABI < 0.90 (p = 0.02). In logistic regression analysis, ABI < 0.90 was an independent predictor for cardiovascular events after adjustment for age, low-density lipoprotein cholesterol, carotid and femoral intima-media thickness, and Gensini score. Further adjustment for the confounding effect of insulin weakened the relation between ABI and cardiovascular events (p = 0.1). In conclusion, ABI is a simple index related to the extent of atherosclerosis in coronary and noncoronary arterial beds, reflecting generalized atherosclerosis. ABI could be useful in assessing the risk for cardiovascular events in patients with coronary artery disease.

Atherosclerotic changes of extracoronary arteries are associated with the extent of coronary atherosclerosis.

The aim of the present study was to examine the association between carotid and femoral artery intima media thickness (IMT) and the extent and severity of coronary artery disease (CAD) as well as the effects of traditional vascular risk factors on the atherosclerotic changes in the carotid and femoral arteries. Two hundred twenty-four patients who underwent coronary angiography for suspected CAD were evaluated by B-mode ultrasound imaging of the common carotid, internal carotid, carotid bifurcation, and femoral artery for measurement of IMT; traditional vascular risk factors were also evaluated in these patients. CAD extent was evaluated by the number of diseased vessels and by Gensini score. Age, male gender, and diabetes were common risk factors for higher CAD extent and higher carotid and femoral IMT. Insulin levels were correlated with femoral IMT and CAD extent, whereas blood lipids were correlated predominantly with carotid IMT. IMT from carotid and femoral arteries increased significantly with an increase in CAD extent. Using multiple stepwise regression analysis, the following parameters were found to be independent predictors of CAD extent: male gender (p<0.0001), common femoral artery IMT (p = 0.0028), common carotid artery IMT (p = 0.015), age (p = 0.02), diabetes mellitus (p = 0.035), and carotid artery bulb IMT (p = 0.04). Common femoral IMT was the only independent parameter for predicting Gensini score (p<0.0001). In conclusion, there are territorial differences in the various arterial beds regarding their response to risk factors. Femoral artery and carotid bulb are independent predictors of CAD extent and the inclusion of these measurements would add information to that provided by the common carotid artery.

Autoantibodies to alpha-synuclein in inherited Parkinson's disease.

Neurodegeneration in Parkinson’s disease (PD) is accompanied by a local immune reaction in the affected brain regions. It is well established that α‐synuclein is directly implicated in the pathogenesis of PD. Development of the disease is often associated with changes of expression and cellular compartmentalisation of this protein; moreover, its oligomers or protofibrils are often released to the CSF and plasma of patients. Aggregated α‐synuclein can trigger the activation of microglia; however, its capacity to induce production of specific autoantibodies (AAb) has not been assessed. In this study, we examined the presence of AAb against synuclein family members in the peripheral blood serum of PD patients and control individuals. Presence of AAb against β‐synuclein or γ‐synuclein showed no association with PD. Multi‐epitopic AAb against α‐synuclein were detected in 65% of all patients tested and their presence strongly correlated with an inherited mode of the disease but not with other disease‐related factors. The frequency of the presence of AAb in the studied group of patients with sporadic form of PD was not significantly different from the frequency in the control group but very high proportion (90%) of patients with familial form of the disease were positive for AAb against α‐synuclein. We hypothesise that these AAb could be involved in pathogenesis of the inherited form of PD.

Evidence for Nonautonomous Effect of p53 Tumor Suppressor in Carcinogenesis

Prostate, breast, and probably other epithelial tumors harbor inactivating mutations in the p53 tumor suppressor gene in the stromal cells, implying the nonautonomous action of p53 in carcinogenesis. We have tested this hypothesis by evaluating the tumorigenicity of MCF7 human breast cancer cells in severe combined immunodeficient mice that differ in their p53 status. Our results showed that, indeed, p53 ablation in the hosts reduced the latency for the development of MCF7 tumors. Furthermore, we show that heterozygous hosts frequently undergo loss of heterozygosity at the p53 locus in the tumor stroma tissue by mechanism that resembles the inactivation of p53 in primary tumors. To evaluate the impact of p53 ablation in the stromal fibroblasts, in tumorigenesis, tumors were reconstituted in mice bearing wild-type p53 alleles, by mixing MCF7 cells with fibroblasts isolated from mutant or wild-type p53 mice. Our results suggest that tumors containing p53-deficient fibroblasts developed faster and were more aggressive than their counterparts with wild-type fibroblasts, although their neoplastic component, namely MCF7 mammary carcinoma cells, was identical in both cases. These data strongly support the notion for the operation of a nonautonomous mechanism for p53 action in primary tumors and provide a mechanistic association between p53 mutations in the stromal component of epithelial tumors and carcinogenesis.

Increased levels of serum advanced glycation end-products in women with polycystic ovary syndrome

objective  Women with polycystic ovary syndrome (PCOS) carry a number of cardiovascular risk factors and are considered to be at increased risk for atherosclerosis. Elevated concentrations of advanced glycation end‐products (AGE), which exert their effects through interaction with specific receptors (RAGE), have been implicated in the cellular and tissue damage during atherosclerotic processes.

Increased plasma levels of 8-iso-PGF2α and IL-6 in an elderly population with depression

Oxidative damage and immune-inflammatory activation have been suggested to play a role in depression. The purpose of the study was to investigate possible associations and interactions of these pathophysiological mechanisms in geriatric depression by determining the levels of plasma 8-iso-prostaglandin F(2alpha) (8-iso-PGF(2alpha)) and interleukin-6 (IL-6) in elderly depressed individuals. Subjects over 60 years of age with depression and controls were randomly selected from a population in the community after screening with the Geriatric Depression Scale. Plasma concentrations of 8-iso-PGF2alpha and IL-6 were measured in both groups. Depressed patients had significantly higher mean (+/-S.D.) 8-iso-PGF2alpha levels compared to healthy controls (245.01+/-179.92 pg/ml vs 97.64+/-42.72 pg/ml, respectively). Similarly, the same groups demonstrated significantly elevated IL-6 levels compared with controls (58.73+/-39.90 pg/ml vs 15.41+/-9.27 pg/ml). This study indicates an association between increased levels of plasma 8-iso-PGF2alpha and IL-6 with depressive symptomatology in elderly individuals and indicates the necessity for further investigation, possibly within the framework of an integrated involvement of oxidative damage and inflammation in the pathophysiology of depression in the elderly.

Cytokine Secretion in Long-standing Diabetes Mellitus Type 1 and 2: Associations with Low-grade Systemic Inflammation

Low-grade systemic chronic inflammation is a very well-known feature of diabetes mellitus (DM). The purpose of this study was the assessment of the proinflammatory cytokine secretion profile in long-standing diabetes along with the presence of features of systemic inflammation. Metabolic parameters and serum high-sensitivity C-reactive protein, interleukin-1β, interleukin-6, and tumor necrosis factor-α levels were determined in 20 patients with type 1 DM and 21 patients with type 2 DM and compared to 34 healthy subjects. The number of cytokine-secreting peripheral blood mononuclear cells (PBMCs), before and after mitogenic stimulation, was also determined in the same groups. Adverse lipid profile, higher levels of inflammatory markers, and higher count of cytokine-secreting cells were observed more prevalently in type 2 diabetics than in controls. After stimulation, the increase in number of cytokine-secreting cells was higher in controls. In conclusion, patients with DM have evidence of low-grade inflammation and abnormal PBMC function that could be related to long-term sequelae, the accelerated atherosclerotic process, and the susceptibility to infections.

Evaluation of serum lipids and high-density lipoprotein subfractions (HDL2, HDL3) in postmenopausal patients with breast cancer.

Breast cancer patients are known to be at increased risk for developing other chronic diseases including cardiovascular disease. Studies by different investigators have shown a correlation between increased dietary fat or hypercholesterolemia and the occurrence of breast cancer. Since previous studies on lipoprotein subfractions in this type of cancer have been inconsistent, we evaluated the lipids and lipoprotein subfraction levels in postmenopausal patients with breast cancer in an attempt to identify the risk for the development of cardiovascular disease.The study included 132 patients, 56 of which were suffering from breast cancer, 32 from pancreatic and 44 age-matched controls. Total cholesterol (TC), triglycerides and lipoprotein fractions as well as TC/High density lipoprotein (HDL) and HDL2/HDL3 ratios were estimated by standard laboratory techniques.An increase in triglycerides and a decrease in HDL-cholesterol, especially in the HDL2 subfraction, were observed in patients with breast cancer as compared to the controls (P < 0.05). The maximum changes in TC, and HDL concentrations were observed in patients with advanced disease. Analysis of indexes of atherosclerosis (TC/HDL, and HDL2/HDL3 ratios) demonstrated that breast cancer patients had significantly higher TC/HDL ratio (6.44 ± 1.24) compared with controls (3.43 ± 0.57, p = 0.001), and patients with pancreatic cancer (3.79 ± 0.15, p = 0.027).The results have demonstrated an unfavourable lipid profile in untreated breast cancer patients with high atherosclerosis indexes. This observation is of great importance, considering the potential use of endocrine therapy that could result in further deterioration of lipid indexes. We propose the evaluation and monitoring of lipid profile prior and after the induction of hormonal therapy in breast cancer patients, as a routine in clinical setting. (Mol Cell Biochem 268: 19–24, 2005)

Ligand-dependent and -independent effects of splice variant 1 of growth hormone-releasing hormone receptor

Existing evidence indicates that, in addition to its neuroendocrine action, growth hormone-releasing hormone (GHRH) acts directly on several nonpituitary tissues, especially neoplasms, and stimulates cell proliferation. We have recently reported that a splice variant of the receptor (SV1) is expressed in various normal tissues and particularly in tumor tissues, producing mitogenic effects on GHRH binding. By using HEC-1A human endometrial carcinoma cells, which express endogenous SV1, we show that, in addition to its ability to mediate the mitogenic effects of GHRH, SV1 also possesses relatively high intrinsic, ligand-independent activity. By using an antisense RNA-based approach we found that SV1 ablation reduces the efficacy of colony formation and the rate of cell proliferation of HEC-1A cells in the absence of exogenous GHRH, and decreases their sensitivity to GHRH when the neurohormone is added to the culture media. This ligand-independent stimulation of cell proliferation appears to be a characteristic property of the truncated form of the receptor, because the expression of SV1 and not of the full-length GHRH receptor stimulated the proliferation of 3T3 fibroblasts in the absence of exogenous GHRH, whereas both forms mediated the proliferative effects of GHRH. Evaluation of 21 specimens of human primary endometrial carcinoma for expression of SV1 by immunohistochemistry indicated that in contrast to the GHRH receptor, which is absent, SV1 is expressed in ≈43% of the specimens. These findings indicate that SV1 can operate in a ligand-independent as well as a ligand-dependent manner. The overexpression of this form of GHRH receptor may be associated with carcinogenesis.