The Relationship between Selenoprotein P and Glucose Metabolism in Experimental Studies

Abstract

Selenium is an essential trace element in the diet of mammals which is important for many physiological functions. However, a number of epidemiological studies have suggested that high selenium status is a possible risk factor for the development of type 2 diabetes, although they cannot distinguish between cause and effect. Selenoprotein P (Sepp1) is central to selenium homeostasis and widely expressed in the organism. Here we review the interaction between Sepp1 and glucose metabolism with an emphasis on experimental evidence. In models with or without gene modification, glucose and insulin can regulate Sepp1 expression in the pancreas and liver, and vice versa. Especially in the liver, Sepp1 is regulated virtually like a gluconeogenic enzyme. Combining these data suggests that there could be a feedback regulation between hepatic Sepp1 and pancreatic insulin and that increasing circulating Sepp1 might be the result rather than the cause of abnormal glucose metabolism. Future studies specifically designed to overexpress Sepp1 are needed in order to provide a more robust link between Sepp1 and type 2 diabetes.

Molecular cloning and sequence analysis of selenoprotein W gene and its mRNA expression patterns in response to metabolic status and cadmium exposure in goldfish, Carassius auratus

“…Unexpectedly, recent human trials and animal studies have suggested that long-term Se intake increased the risk of insulin resistance and type 2 diabetes (Bleys et al, 2007;Stranges et al, 2011). Recently, a number of studies have suggested that selenoproteins, such as GPX, SelS and SelP, were also closely associated with diabetes or metabolic syndrome in mammals (Labunskyy et al, 2011;Mao and Teng, 2013;Misu et al, 2010;Seale et al, 2012;Steinbrenner, 2013). No matter the insulin-like effect or the increasing the risk of insulin resistance and type 2 diabetes, at least it is indicated that selenoproteins as the carrier of Se may be related to the glucose and lipid metabolism.…”

Evaluation Of The Relationship Between İnsülin Resistance And Selenoprotein P İn Patients With Polycystic Ovary Syndrome

“…[32] However, some studies have demonstrated a negative correlation between SeP level, gene expression, obesity and IR. [31] In the present study we performed a correlation analysis between SeP and anthropometric parameters, and found negative correlations between SeP and waist circumference in the patient group, and also between SeP and BMI and the percentage of adipose tissue in the control group.…”

“…[30] In a review article written by Mao and Teng, the authors indicated that in a case of normal insulin sensitivity, insulin will suppress release of SeP from the liver, while in the case of IR, this feedback mechanism fails to function and an increase in SeP level occurs, which may induce an increase in blood glucose level. [31] In another study in which 100 patients with varying glucose tolerance levels were evaluated, a higher plasma SeP concentration was detected in cases with normal glucose tolerance relative to cases with type 2 DM or prediabetes, and enhanced plasma SeP levels were found to be positively correlated with BMI and IR. [9] In our study, higher IR was detected in patients with PCOS, though not statistically significantly different, and mean plasma SeP level was lower than that of the control group.…”

“…Since none of our patients had DM, a decreased SeP level in patients with PCOS may be correlated with suppression of SeP level secondary to a higher insulin level. Generally, increased SeP level has been associated with DM and other cardiometabolic risks, [31] though it should be noted that this mechanism has not been clearly established. In a study conducted by Yang et al with 8 patients with IR and 8 control subjects, suppression of SeP gene expression in the subcutaneous tissue was demonstrated in patients with IR.…”

Meta-analysis of selenium accumulation and expression of antioxidant enzymes in chicken tissues

“…It has chemopreventive, anti-inflammatory, antiviral properties and is related in enhancing immunity (Rayman, 2012;Steinbrenner et al, 2013). The health-related properties of Se include but are not limited to protection against cancer, proper function of thyroid gland, and protection against cardiovascular and muscle disorders (Mao and Teng, 2013;Rocourt and Cheng, 2013). Se becomes cotranslationally incorporated into the polypeptide chain as part of the amino-acid selenocysteine (SeCys).…”