Increased expression of the gene encoding stearoyl-CoA desaturase 1 in human bladder cancer.

Bladder cancer is a common disease and a significant cause of death worldwide. There is thus great interest in identifying a diagnostic and prognostic biomarker, as well as gaining an understanding of the molecular basis of bladder cancer. Stearoyl-CoA desaturase 1 gene (SCD1) is highly overexpressed in many human cancers. However, the expression of SCD1 has not yet been investigated in patients with bladder cancer. Here, we document that (a) the SCD1 is highly overexpressed in human bladder cancer; (b) high expression of SCD1 is more frequently observed in the late stage of disease and patients with lymph node metastasis; (c) bladder cancer patients with a higher SCD1 mRNA level have a poorer survival rate than those with normal SCD1 expression. Overall, this is the first report to indicate an association between SCD1 mRNA level and clinical indicators of human bladder cancer. Our study has provided evidence supporting the potential role of SCD1 as a biomarker for human bladder cancer prognosis.

Alterations of specific lipid groups in serum of obese humans: a review.

Obesity is a major contributor to the dysfunction of liver, cardiac, pulmonary, endocrine and reproductive system, as well as a component of metabolic syndrome. Although development of obesity-related disorders is associated with lipid abnormalities, most previous studies dealing with the problem in question were limited to routinely determined parameters, such as serum concentrations of triacylglycerols, total cholesterol, low-density and high-density lipoprotein cholesterol. Many authors postulated to extend the scope of analysed lipid compounds and to study obesity-related alterations in other, previously non-examined groups of lipids. Comprehensive quantitative, structural and functional analysis of specific lipid groups may result in identification of new obesity-related alterations. The review summarizes available evidence of obesity-related alterations in various groups of lipids and their impact on health status of obese subjects. Further, the role of diet and endogenous lipid synthesis in the development of serum lipid alterations is discussed, along with potential application of various lipid compounds as risk markers for obesity-related comorbidities.

Short-term calorie restriction and refeeding differently affect lipogenic enzymes in major white adipose tissue depots of young and old rats.

The metabolic effects of short-term calorie restriction (SCR) and subsequent refeeding were compared in different white adipose tissue (WAT) depots of young (5-month old) and old (24-month) male Wistar rats. The animals were subjected to a 40% calorie restricted diet (i.e. 40% lower food supply than of control rats) for 30 days, and then re-fed for 0, 2, or 4 days. WAT samples from perirenal (pWAT), epididymal (eWAT), and subcutaneous (sWAT) depots were analysed for the enzymatic activities of ATP-citrate lyase (ACL), fatty acid synthase (FAS), and glucose-6-phosphate dehydrogenase (G6PD). The total WAT mass almost doubled in old rats, however, aging did not alter the relative proportions of the major regional fat depots. Serum leptin concentration was prominently higher in old rats, in which SCR resulted in less suppression of leptin level than in young animals, whereas refeeding increased leptin concentration in young, but not old, rats. In young rats refeeding elevated leptin gene expression only in pWAT, while in old rats the expression was induced first in eWAT, and later in pWAT. A prominent age-related decrease of ACL and FAS activities, but not of G6PD activity, was found in all the studied WAT depots. In young control rats, ACL activity was highest in pWAT, FAS activity was similar in all WAT depots, and G6PD activity was lowest in eWAT. In old rats, the enzymatic activities were lower in eWAT than in the other depots. The patterns of response to SCR and refeeding varied by age and WAT location. SCR stimulated ACL activity in pWAT but not in other depots of young rats, while FAS activity in pWAT and sWAT did not change in young and decreased in the old animals. Among the studied depots, pWAT was most responsive to refeeding in both age groups. In conclusion, SCR in old rats, as compared to the young, may be accompanied by reduced 'rebound effect' upon returning to unrestricted diet.

The increase of serum chemerin concentration is mainly associated with the increase of body mass index in obese, non-diabetic subjects.

BACKGROUND: Chemerin is a newly discovered adipokine, whose circulating concentration is increased in obesity. AIM: To elucidate whether the increased circulating chemerin concentrations in obese subjects are associated with the increase of fat mass, the increase in chemerin gene expression in adipose tissue or both. MATERIAL/SUBJECTS AND METHODS: Serum chemerin concentrations in 20 non-obese healthy volunteers and 21 non-diabetic obese subjects were measured using ELISA. Chemerin mRNA and chemerin protein levels in visceral and subcutaneous adipose tissues of obese subjects were analyzed by Real-Time PCR and Western blot respectively. RESULTS: We found that the serum chemerin concentrations were significantly higher in obese subjects than in controls and positively correlated with BMI, fat mass and body mass. Moreover serum chemerin concentrations were correlated positively with serum CRP concentrations independently of BMI. No correlation was found between the chemerin mRNA and chemerin protein levels in visceral and subcutaneous adipose tissues and BMI, fat mass, or body weight. Likewise, there was no correlation between the serum chemerin concentrations and the levels of chemerin mRNA and protein in adipose tissue of obese patients. Multiple regression analysis suggests that BMI was the main predictor of serum chemerin concentration. In contrast to chemerin, both serum leptin concentrations and adipose tissue leptin mRNA levels positively correlated with BMI. CONCLUSIONS: The results presented here indicate that serum chemerin concentrations correlated with BMI, whereas chemerin mRNA levels in adipose tissue did not. Thus the elevated circulating chemerin concentration in obese, non-diabetic patients was mainly associated with the increased BMI.

Decrease in serum protein carbonyl groups concentration and maintained hyperhomocysteinemia in patients undergoing bariatric surgery.

BACKGROUND: Human obesity is associated with oxidative stress but the factors contributing to the increase of reactive oxygen species (ROS) production remain unknown. We evaluated the association between serum homocysteine concentration, which may increase ROS production, and serum protein carbonyl groups concentration before and after bariatric surgery. METHODS: Serum protein carbonyl groups and serum homocysteine concentrations, as well as obesity markers, were compared in 18 obese patients before and 6 months after bariatric surgery. Ten healthy individuals with normal body mass index (BMI) served as controls. RESULTS: Before bariatric surgery, obese patients displayed approximately 50% higher serum protein carbonyl groups concentration than control subjects. After surgery, serum protein carbonyl groups concentration decreased and matched values observed in controls. Serum homocysteine concentration was also elevated in obese patients, but in contrast to protein carbonyl groups, did not change after surgery. The body weight, BMI, HOMA-IR, serum leptin, triacylglycerols, LDL/HLD cholesterol ratio, insulin, and glucose concentrations were higher in obese patients as compared to controls, and decreased after bariatric surgery. CONCLUSIONS: This study demonstrates that bariatric surgery has protective effect on oxidative protein damage and improves several laboratory parameters including serum lipid concentration and insulin resistance. However, bariatric surgery does not cause a decrease in serum homocysteine concentration, a risk factor for the development of cardiovascular diseases. Collectively, the results presented in this paper suggest that serum homocysteine concentration is not directly associated with oxidative stress in obese patients after bariatric surgery.