Increased production of proinflammatory cytokines in adipose tissue of patients with end-stage renal disease.

OBJECTIVE: The number of patients with end-stage renal disease (ESRD) is rising and these patients are at higher risk of cardiovascular disease. We studied the role of hormonal production of adipose tissue in the development of chronic inflammation in patients with ESRD before kidney transplantation. METHODS: Fifteen women with ESRD and 17 healthy women (control) underwent single blood drawing and visceral and subcutaneous adipose tissue sampling during surgery (kidney transplantation in the ESRD group or cholecystectomy in the control group). Serum concentrations of C-reactive protein, interleukin-6, tumor necrosis factor-alpha, leptin, adiponectin, resistin, monocyte chemoattractant protein-1 were measured. Messenger RNA expression of the same hormones, adiponectin receptors 1 and 2 and immunocompetent cell marker CD68 in subcutaneous and visceral samples were measured using real-time polymerase chain reaction. Adipose tissue was examined immunohistochemically for CD68-positive cells. RESULTS: Serum concentrations of C-reactive protein, adiponectin, resistin, interleukin-6, tumor necrosis factor-alpha, and monocyte chemoattractant protein-1 were significantly higher in the ESRD versus control group. Subcutaneous and visceral mRNA expressions of tumor necrosis factor-alpha and CD68 were significantly increased in the ESRD versus control group. Adiponectin receptor-1 and monocyte chemoattractant protein-1 mRNA expressions were significantly higher in visceral but not in subcutaneous adipose tissue of the ESRD group. Messenger RNA expressions of resistin, leptin, adiponectin, interleukin-6, and adiponectin receptor-2 in both fat depots did not significantly differ between groups. Increased infiltration of subcutaneous and visceral adipose tissue with CD68-positive immunocompetent cells was found in the ESRD group by histologic examination. CONCLUSION: Subcutaneous and visceral adipose tissues in ESRD express higher amounts of proinflammatory cytokines and may play a role in the development of systemic inflammation.

Comparison of manual and automatic (MagNA Pure) isolation methods of total RNA from adipose tissue.

AIM: Comparison of manual and automatic (MagNA Pure) isolation methods of total RNA from adipose tissue with respect to its quality and recovery factor. MATERIAL: 120 human subcutaneous adipose tissue samples (about 100 mg/sample) were collected from patients during surgical operations. The tissue sample was stabilized in RNAlater (QIAGEN GmbH, Germany). METHODS: Total RNA was extracted by the following kits: Rneasy Protect Mini, Rneasy Lipid Tissue (QIAGEN GmbH, Germany) and MagNA Pure Compact RNA Isolation (Tissue) for MagNA Pure Compact Instrument (Roche Diagnostics GmbH, Germany). RESULTS: The average RNA yields with Rneasy Lipid Tissue kits were about two-fold higher in comparison with the Rneasy Protect Mini kit. When the MagNA Pure Compact System was used, RNA yields from the same sample were more uniform compared with manual systems. It was also more convenient and less time-consuming than the manual approach. No DNA contamination of total RNA samples was detected except for samples isolated by Rneasy Protect Mini Kit. CONCLUSION: Rneasy Lipid Tissue Kit and MagNA Pure Compact RNA Isolation Kit (Tissue) provide RNA samples of high quantity, purity and PCR amplificability. RNA samples are suitable for further processing using methods of molecular biology.

Increased subcutaneous and epicardial adipose tissue production of proinflammatory cytokines in cardiac surgery patients: possible role in postoperative insulin resistance.

CONTEXT: Hyperglycemia and insulin resistance frequently occur in critically ill patients even without a history of diabetes. OBJECTIVE: Our objective was to study the role of adipose tissue hormonal production in the development of insulin resistance in cardiac surgery patients. PARTICIPANTS, INTERVENTIONS, AND SETTINGS: Fifteen patients with elective cardiac surgery underwent blood sampling before, at the end, and 6, 12, 24, 48, and 120 h after the end of their operation. Epicardial and sc adipose tissue sampling was done at the beginning and at the end of surgery in the Department of Cardiac Surgery. MAIN OUTCOME MEASURES: We measured serum concentrations and sc and epicardial adipose tissue mRNA expression of IL-6, monocyte chemoattractant protein-1 (MCP-1), TNF-alpha, leptin, resistin, and adiponectin and sc and epicardial adipose tissue mRNA expression of CD14, CD45, and CD68. RESULTS: The rate of insulin infusion required to maintain euglycemia increased up to 7-fold 12 h after the operation, suggesting the development of insulin resistance. Serum IL-6 levels increased 43-fold 12 h after surgery. MCP-1 peaked 6-fold at the end of surgery. Smaller peaks of TNF-alpha and leptin appeared 6 and 12 h after surgery, respectively. Resistin levels peaked 4-fold 24 h after surgery, but adiponectin levels were not significantly affected. TNF-alpha and CD45 mRNA expression increased markedly during the operation in sc adipose tissue. IL-6, resistin, and MCP-1 mRNA expression increased in both sc and epicardial adipose tissue. Leptin, adiponectin, CD14, and CD68 mRNA expression did not change significantly. CONCLUSIONS: Both sc and epicardial adipose tissue is a source of proinflammatory cytokines in cardiac surgery patients and may contribute to the development of postoperative insulin resistance.