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2.  Munc18c in Adipose Tissue Is Downregulated in Obesity and Is Associated with Insulin 
PLoS ONE  2013;8(5):e63937.
Munc18c is associated with glucose metabolism and could play a relevant role in obesity. However, little is known about the regulation of Munc18c expression. We analyzed Munc18c gene expression in human visceral (VAT) and subcutaneous (SAT) adipose tissue and its relationship with obesity and insulin.
Materials and Methods
We evaluated 70 subjects distributed in 12 non-obese lean subjects, 23 overweight subjects, 12 obese subjects and 23 nondiabetic morbidly obese patients (11 with low insulin resistance and 12 with high insulin resistance).
The lean, overweight and obese persons had a greater Munc18c gene expression in adipose tissue than the morbidly obese patients (p<0.001). VAT Munc18c gene expression was predicted by the body mass index (B = −0.001, p = 0.009). In SAT, no associations were found by different multiple regression analysis models. SAT Munc18c gene expression was the main determinant of the improvement in the HOMA-IR index 15 days after bariatric surgery (B = −2148.4, p = 0.038). SAT explant cultures showed that insulin produced a significant down-regulation of Munc18c gene expression (p = 0.048). This decrease was also obtained when explants were incubated with liver X receptor alpha (LXRα) agonist, either without (p = 0.038) or with insulin (p = 0.050). However, Munc18c gene expression was not affected when explants were incubated with insulin plus a sterol regulatory element-binding protein-1c (SREBP-1c) inhibitor (p = 0.504).
Munc18c gene expression in human adipose tissue is down-regulated in morbid obesity. Insulin may have an effect on the Munc18c expression, probably through LXRα and SREBP-1c.
PMCID: PMC3659121  PMID: 23700440
3.  Adipose Tissue Characteristics Related to Weight Z-Score in Childhood 
Childhood obesity has grown very fast over recent decades and now it represents a serious public health problem. The number of adipocytes is set in childhood and adolescence and then, an effective understanding of the development of adipose tissue during these periods will help in the prevention of this pathology.
The current study aimed to determine which adipose tissue characteristics are related to a high weight Z-score in childhood.
Patients and Methods
The current study included 82 children aged 5-130 months who underwent inguinal hernia surgery. Anthropometric variables were measured, and a nutritional and physical activity questionnaire was completed. Subcutaneous adipose tissue samples, taken during the operation, were analyzed for preadipocyte number, adipocyte volume, fatty acid composition (gas chromatography of FAME), and relative gene expression of various genes (real time PCR).
The results showed that children with a higher weight Z-score spend more time in sedentary activities and less time running or involved in active games. SCD-1 activity index, arachidonic/linoleic index, and adipocyte volume were significantly higher in children with a weight Z-score greater than 0. The preadipocyte number and the genetic expression of the studied genes did not differ between the groups. A multiple regression analysis was done to determine which variables were related to the weight Z-score. R2 values indicated that the model which included adipocyte volume, SREBP-1c, SCD-1 expression, and activity index, predicted 59% of the variability in the weight Z-score among the children. The main variables associated with adipocyte volume were PPARγ, Adiponectin, CB1R expressions, as well as the SCD-1 activity and normalized weight.
It was concluded that in childhood, the weight Z-score is related to adipocyte volume and adipose tissue gene expression.
PMCID: PMC3693669  PMID: 23825978
Adipose Tissue; Adipocyte; Adipokines; PPAR gamma; Adiponectin
4.  Obesity-associated insulin resistance is correlated to adipose tissue vascular endothelial growth factors and metalloproteinase levels 
BMC Physiology  2012;12:4.
The expansion of adipose tissue is linked to the development of its vasculature, which appears to have the potential to regulate the onset of obesity. However, at present, there are no studies highlighting the relationship between human adipose tissue angiogenesis and obesity-associated insulin resistance (IR).
Our aim was to analyze and compare angiogenic factor expression levels in both subcutaneous (SC) and omentum (OM) adipose tissues from morbidly obese patients (n = 26) with low (OB/L-IR) (healthy obese) and high (OB/H-IR) degrees of IR, and lean controls (n = 17). Another objective was to examine angiogenic factor correlations with obesity and IR.
Here we found that VEGF-A was the isoform with higher expression in both OM and SC adipose tissues, and was up-regulated 3-fold, together with MMP9 in OB/L-IR as compared to leans. This up-regulation decreased by 23% in OB/-H-IR compared to OB/L-IR. On the contrary, VEGF-B, VEGF-C and VEGF-D, together with MMP15 was down-regulated in both OB/H-IR and OB/L-IR compared to lean patients. Moreover, MMP9 correlated positively and VEGF-C, VEGF-D and MMP15 correlated negatively with HOMA-IR, in both SC and OM.
We hereby propose that the alteration in MMP15, VEGF-B, VEGF-C and VEGF-D gene expression may be caused by one of the relevant adipose tissue processes related to the development of IR, and the up-regulation of VEGF-A in adipose tissue could have a relationship with the prevention of this pathology.
PMCID: PMC3382430  PMID: 22471305
Vascular Endothelial Growth Factor and Metalloproteinase; Obesity; Insulin Resistance; Omentum Adipose Tissue; Subcutaneous Adipose Tissue

Results 1-4 (4)