Tetranectin as a Novel Obesity-associated Adipokine for Regulating Lipid Accumulation

Tetranectin as a Novel Obesity-associated Adipokine for Regulating Lipid Accumulation

Adipose tissue is strongly correlated to obesity and diabetes which are two major problems in the worldwide. Adipose tissue is involved in modulating glucose and energy metabolism locally and systemically by secreting factors, called adipocytokines. Tetranectin (TN), a novel adipocytokine, is secreted by adipose tissues. TN may regulate the glucose/energy homeostasis to affect lipid accumulation.The role of TN in adipocytes with or without TN on regulation of adipose tissue growth and lipid metabolism is valuable to be studied.

Materials and methods: Secreted proteins from human adipocyte culture medium were deciphered using 2-D polyacrylamide gel electrophoresis and determined by LC/MS with MALDI-TOF analysis of proteins. Adipose tissues were obtained from the breast of 15 women undergoing mastectomy. Serum samples from 200 normal healthy people and 54 breast cancer patients were assigned to either a lean or obese group according to the body mass index. The TN protein concentration was measured in the culture medium of stromal-vascular fraction (SVF)-derived adipocytes from healthy humans, breast cancer patients, pigs and also from 3T3-L1 cells. Associations between plasma TN and other biomarkers were assessed with Pearson's correlations and multivariable linear regression.

Adipose tissues were obtained from the breast of breast cancer patients with 0 to 1 progression stage. All participants gave permission and the study was approved by the Ethics Committee of National Taiwan University Hospital as no. 9461701203.

From 2012 to 2013 in National Taiwan University Hospital, a cross-sectional sampling of 21 to 78 -year old people included women and men who were living in Taiwan. Blood samples were collected after an overnight fasting. Serum was separated by centrifugation and stored at -80 ℃ until analysis. Plasma triglyceride (TG), high density lipoprotein (HDL), low density lipoprotein (LDL), cholesterol, glucose and insulin were measured. Fasting serum samples were obtained from 193 randomly selected persons having health check-ups. To investigate the relationship among TN and breast cancer, fasting serum samples also obtained from 54 randomly selected breast cancer patients who were 25 to 59 years old with elected surgery for breast cancer stage 0 and 1.

Inclusion Criteria:

1. Must be above age 20 years old.
2. Subjects must sign the written informed consent form.
3. Must have residual fat after surgery.
4. Clinical diagnosis of liposuction and tumor resection.

Exclusion Criteria:

1. Terminal cancer.
2. Subjects have no fat tissue after surgery.
3. Pregnant subjects.