Serum vaspin and adiponectin levels in patients with prolactinoma

Evaluation of Tissue Expression of Vaspin and Serum Vaspin Concentration as a Prognostic and Risk Factor in Endometrial Cancer

Adipose tissue is a multifunctional endocrine organ. One of the biologically active substances is vaspin, which is part of the serpin family. The purpose of the following study is to determine the possibility of using vaspin as a prognostic and risk factor in endometrial cancer. The study included 127 patients with abnormal uterine bleeding. To determine the value of adipokine, the study used Kaplan-Meier curves to estimate patients survival. Univariate and multivariate analyses were performed simultaneously using the Cox regression model. Tissue expression of vaspin was assessed in patients from the study group (endometrial cancer) and the control group (non-cancerous). We found that higher levels of vaspin are found in obese people, with lower staging (FIGO I and II), lower grading (G1), no LVSI metastases and no lymph node metastases. Higher serum vaspin levels are an independent protective factor for endometrial cancer. We concluded that endometrial cancer patients with serum vaspin concentrations above the median have longer DFS compared to patients with concentrations below the median. Considering multivariate analysis, vaspin concentrations above the median are independent favourable prognostic factors for endometrial cancer. Tissue expression of vaspin cannot be a histological marker to distinguish between cancer and non-cancerous lesions and between different grading levels.

Review: Vaspin (SERPINA12) Expression and Function in Endocrine Cells

Proper functioning of the body depends on hormonal homeostasis. White adipose tissue is now known as an endocrine organ due to the secretion of multiple molecules called adipokines. These proteins exert direct effects on whole body functions, including lipid metabolism, angiogenesis, inflammation, and reproduction, whereas changes in their level are linked with pathological events, such as infertility, diabetes, and increased food intake. Vaspin-visceral adipose tissue-derived serine protease inhibitor, or SERPINA12 according to serpin nomenclature, is an adipokine discovered in 2005 that is connected to the development of insulin resistance, obesity, and inflammation. A significantly higher amount of vaspin was observed in obese patients. The objective of this review was to summarize the latest findings about vaspin expression and action in endocrine tissues, such as the hypothalamus, pituitary gland, adipose tissue, thyroid, ovary, placenta, and testis, as well as discuss the link between vaspin and pathologies connected with hormonal imbalance.

The modulation of adiponectin by STAT5-activating hormones

Adiponectin is a hormone secreted from adipocytes that plays an important role in insulin sensitivity and protects against metabolic syndrome. Growth hormone (GH) and prolactin (PRL) are potent STAT5 activators that regulate the expression of several genes in adipocytes. Studies have shown that the secretion of adiponectin from adipose tissue is decreased by treatment with PRL and GH. In this study, we demonstrate that 3T3-L1 adipocytes treated with GH or PRL exhibit a reduction in adiponectin protein levels. Furthermore, we identified three putative STAT5 binding sites in the murine adiponectin promoter and show that only one of these, located at -3,809, binds nuclear protein in a GH- or PRL-dependent manner. Mutation of the STAT5 binding site reduced PRL-dependent protein binding, and supershift analysis revealed that STAT5A and -5B, but not STAT1 and -3, bind to this site in response to PRL. Chromatin immunoprecipitation (IP) analysis demonstrated that only STAT5A, and not STAT1 and -3, bind to the murine adiponectin promoter in a GH-dependent manner in vivo. Adiponectin promoter/reporter constructs were responsive to GH, and chromatin IP analysis reveals that STAT5 binds the adiponectin promoter in vivo following GH stimulation. Overall, these data strongly suggest that STAT5 activators regulate adiponectin transcription through the binding of STAT5 to the -3,809 site that leads to decreased adiponectin expression and secretion. These mechanistic observations are highly consistent with studies in mice and humans that have high GH or PRL levels that are accompanied by lower circulating levels of adiponectin.