AUTHOR=Lopez-Vicchi Felicitas , De Winne Catalina , Ornstein Ana Maria , Sorianello Eleonora , Toneatto Judith , Becu-Villalobos Damasia 

TITLE=Severe Hyperprolactinemia Promotes Brown Adipose Tissue Whitening and Aggravates High Fat Diet Induced Metabolic Imbalance

JOURNAL=Frontiers in Endocrinology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2022.883092

DOI=10.3389/fendo.2022.883092

ISSN=1664-2392

ABSTRACT=<sec><title>Background</title><p>The association of high serum prolactin and increased body weight is positive but controversial, therefore we hypothesized that additional factors such as diets and the impact of prolactin on brown adipose tissue may condition its metabolic effects.</p></sec><sec><title>Methods</title><p>We used LacDrd2KO females with lifelong severe hyperprolactinemia due dopamine-D2 receptor deletion from lactotropes, and slow onset of metabolic disturbances, and compared them to their respective controls <italic>(Drd2 <sup>loxP/loxP</sup></italic>). Food intake, and binge eating was evaluated. We then challenged mice with a High Fat (HFD) or a Control Diet (CD) for 8 weeks, beginning at 3 months of age, when no differences in body weight are found between genotypes. At the end of the protocol brown and white adipose tissues were weighed, and thermogenic and lipogenic markers studied, using real time PCR (<italic>Ucp1, Cidea, Pgc1a, Lpl, adiponectin, Prlr</italic>) or immunohistochemistry (UCP1). Histochemical analysis of brown adipose tissue, and glucose tolerance tests were performed.</p></sec><sec><title>Results</title><p>Hyperprolactinemic mice had increased food intake and binge eating behavior. Metabolic effects induced by a HFD were exacerbated in lacDrd2KO mice. Hyperprolactinemia aggravated HFD-induced body weight gain and glucose intolerance. In brown adipose tissue pronounced cellular <italic>whitening</italic> as well as decreased expression of the thermogenic markers <italic>Ucp1</italic> and <italic>Pgc1a</italic> were observed in response to high prolactin levels, regardless of the diet, and furthermore, hyperprolactinemia potentiated the decrease in <italic>Cidea</italic> mRNA expression induced by HFD. In subcutaneous white adipose tissue hyperprolactinemia synergistically increased tissue weight, while decreasing <italic>Prlr</italic>, Adiponectin and <italic>Lpl</italic> mRNA levels regardless of the diet.</p></sec><sec><title>Conclusions</title><p>Pathological hyperprolactinemia has a strong impact in brown adipose tissue, lowering thermogenic markers and evoking tissue whitening. Furthermore, it modifies lipogenic markers in subcutaneous white adipose, and aggravates HFD-induced glucose intolerance and <italic>Cidea</italic> decrease. Therefore, severe high prolactin levels may target BAT function, and furthermore represent an adjuvant player in the development of obesity induced by high fat diets.</p></sec>