Expression of Adipocyte-Associated Genes in the Mouse Tail Epididymal Fat at Different Postnatal Ages

Abstract

The fat pad defined as the epididymal fat is located at the head part of the epididymis. However, another fat mass is present near the caudal epididymis, named tail epididymal fat. The present research was focused to determine the expression of adipocyte-associated molecules in the mouse tail epididymal fat at different postnatal ages, including 2, 5, 8, and 12 months of age. The quantitative real-time PCR analysis showed continuous increases of expression levels of delta like non-canonical Notch ligand 1, leptin, and resistin as postnatally aged. The transcript level of peroxisome proliferator-activated receptor gamma was the highest at 5 months of age, remaining at a steady level until 12 months of age. Expression levels of fatty acid binding protein 4, leptin, and adiponectin were significantly increased until 8 months of age, persisting the level at 12 months of age. The transcript level of fatty acid synthase was significantly increased at 8 months of age, without a further change of the level at 12 months of age. These findings exhibited the expression of adipocyte-associated genes which were also detected at the ordinary epididymal fat pad. However, expression patterns of these genes in the tail epididymal fat are different with those in the distal and proximal epididymal fat, suggesting distinct characteristics and/or functions of the tail epididymal fat.

Expressional Evaluation of C/EBP Family, SREBP1, and Steroid Hormone Receptors in the Epididiymal Fat of Postnatally Developing Mouse

“…The epididymal fat is a part of gonadal adipose tissue and is located nearby the epididymis, as named ( Berry et al, 2013 ; Lee, 2020 ). Based on histochemical characteristics and/or relative localization, the epididymal fat is discriminated into three types, distal, proximal, and tail epididymal fat ( Tirard et al, 2007 ; Lee, 2020 ).…”

“…The epididymal fat is a part of gonadal adipose tissue and is located nearby the epididymis, as named ( Berry et al, 2013 ; Lee, 2020 ). Based on histochemical characteristics and/or relative localization, the epididymal fat is discriminated into three types, distal, proximal, and tail epididymal fat ( Tirard et al, 2007 ; Lee, 2020 ). The distal and proximal epididymal fat is the typically known epididymal fat pad, and differential gene expression between these epididymal fat parts has been observed from our previous and other researches, indicating functional differences between distal and proximal epididymal fat parts ( Tirard et al, 2007 ; Lee & Kim, 2019 ; Lee, 2019 ).…”

“…The distal and proximal epididymal fat is the typically known epididymal fat pad, and differential gene expression between these epididymal fat parts has been observed from our previous and other researches, indicating functional differences between distal and proximal epididymal fat parts ( Tirard et al, 2007 ; Lee & Kim, 2019 ; Lee, 2019 ). The tail epididymal fat is localized on the caudal epididymis and is continuously enlarged in size as aged ( Lee, 2020 ). Even though the histochemical characteristics and function of tail epididymal fat have not been defined yet, expression patterns of some adipocyte-associated molecules in the tail epididymal fat are distinct from those detected in the distal and proximal epididymal fat pads ( Lee, 2020 ).…”

Assessment of Adipocyte Differentiation and Maturation-related Gene Expression in the Epididymal Fat of Estrogen Receptor α Knockout (ERαKO) Mouse during Postnatal Development Period

“…The continuous growth and expansion in size during the lifetime is a characteristic of fat tissue, unlike other tissues having limited developmental capacity ( Hausman et al, 2001 ). The epididymal fat is a gonadal fat belonging to interperitoneal white adipose tissue, most of the epididymal fat is present near the head of epididymis ( Berry et al, 2013 ; Lee, 2020 ). Based on the location and histochemical characteristics, the epididymal fat pad is divided into distal, proximal, and tail epididymal fat ( Tirard et al, 2007 ; Lee, 2020 ).…”

“…The epididymal fat is a gonadal fat belonging to interperitoneal white adipose tissue, most of the epididymal fat is present near the head of epididymis ( Berry et al, 2013 ; Lee, 2020 ). Based on the location and histochemical characteristics, the epididymal fat pad is divided into distal, proximal, and tail epididymal fat ( Tirard et al, 2007 ; Lee, 2020 ). The epididymal fat tissue contains several cell types, including mature adipocyte, preadipocytes, immune cell, and endothelial cell ( Cleary et al, 1977 ).…”