TY - JOUR
T1 - Anthropometric and glucometabolic changes in an aged mouse model of lipocalin-2 overexpression
AU - Principi, Elisa
AU - Buschiazzo, Ambra
AU - Papait, Andrea
AU - Castagnola, Patrizio
AU - Costa, Delfina
AU - Pece, Roberta
AU - Maric, Irena
AU - Scussolini, Mara
AU - Marini, Cecilia
AU - Sambuceti, Gianmario
AU - Strollo, Felice
AU - Tavella, Sara
PY - 2019/1/1
Y1 - 2019/1/1
N2 - Background:: Lipocalin-2 (LCN2) is widely expressed in the organism with pleiotropic roles. In particular, its overexpression correlates with tissue stress conditions including inflammation, metabolic disorders, chronic diseases and cancer. Objectives:: To assess the effects of systemic LCN2 overexpression on adipose tissue and glucose metabolism. Subjects:: Eighteen-month-old transgenic mice with systemic LCN2 overexpression (LCN2-Tg) and age/sex-matched wild-type mice. Methods:: Metabolic cages; histology and real-time PCR analysis; glucose and insulin tolerance tests; ELISA; flow cytometry; microPET and serum analysis. Results:: LCN2-Tg mice were smaller compared to controls but they ate (P = 0.0156) and drank (P = 0.0057) more and displayed a higher amount of visceral adipose tissue. Furthermore, LCN2-Tg mice with body weight ≥20 g showed adipocytes with a higher cell area (P < 0.0001) and altered expression of genes involved in adipocyte differentiation and inflammation. In particular, mRNA levels of adipocyte-derived Pparg (P ≤ 0.0001), Srebf1 (P < 0.0001), Fabp4 (P = 0.056), Tnfa (P = 0.0391), Il6 (P = 0.0198), and Lep (P = 0.0003) were all increased. Furthermore, LCN2-Tg mice displayed a decreased amount of basal serum insulin (P = 0.0122) and a statistically significant impaired glucose tolerance and insulin sensitivity consistent with Slc2a2 mRNA (P ≤ 0.0001) downregulated expression. On the other hand, Insr mRNA (P ≤ 0.0001) was upregulated and correlated with microPET analysis that demonstrated a trend in reduced whole-body glucose consumption and MRGlu in the muscles and a significantly reduced MRGlu in brown adipose tissue (P = 0.0247). Nevertheless, an almost nine-fold acceleration of hexokinase activity was observed in the LCN2-Tg mice liver compared to controls (P = 0.0027). Moreover, AST and ALT were increased (P = 0.0421 and P = 0.0403, respectively), which indicated liver involvement also demonstrated by histological staining. Conclusions:: We show that LCN2 profoundly impacts adipose tissue size and function and glucose metabolism, suggesting that LCN2 should be considered as a risk factor in ageing for metabolic disorders leading to obesity.
AB - Background:: Lipocalin-2 (LCN2) is widely expressed in the organism with pleiotropic roles. In particular, its overexpression correlates with tissue stress conditions including inflammation, metabolic disorders, chronic diseases and cancer. Objectives:: To assess the effects of systemic LCN2 overexpression on adipose tissue and glucose metabolism. Subjects:: Eighteen-month-old transgenic mice with systemic LCN2 overexpression (LCN2-Tg) and age/sex-matched wild-type mice. Methods:: Metabolic cages; histology and real-time PCR analysis; glucose and insulin tolerance tests; ELISA; flow cytometry; microPET and serum analysis. Results:: LCN2-Tg mice were smaller compared to controls but they ate (P = 0.0156) and drank (P = 0.0057) more and displayed a higher amount of visceral adipose tissue. Furthermore, LCN2-Tg mice with body weight ≥20 g showed adipocytes with a higher cell area (P < 0.0001) and altered expression of genes involved in adipocyte differentiation and inflammation. In particular, mRNA levels of adipocyte-derived Pparg (P ≤ 0.0001), Srebf1 (P < 0.0001), Fabp4 (P = 0.056), Tnfa (P = 0.0391), Il6 (P = 0.0198), and Lep (P = 0.0003) were all increased. Furthermore, LCN2-Tg mice displayed a decreased amount of basal serum insulin (P = 0.0122) and a statistically significant impaired glucose tolerance and insulin sensitivity consistent with Slc2a2 mRNA (P ≤ 0.0001) downregulated expression. On the other hand, Insr mRNA (P ≤ 0.0001) was upregulated and correlated with microPET analysis that demonstrated a trend in reduced whole-body glucose consumption and MRGlu in the muscles and a significantly reduced MRGlu in brown adipose tissue (P = 0.0247). Nevertheless, an almost nine-fold acceleration of hexokinase activity was observed in the LCN2-Tg mice liver compared to controls (P = 0.0027). Moreover, AST and ALT were increased (P = 0.0421 and P = 0.0403, respectively), which indicated liver involvement also demonstrated by histological staining. Conclusions:: We show that LCN2 profoundly impacts adipose tissue size and function and glucose metabolism, suggesting that LCN2 should be considered as a risk factor in ageing for metabolic disorders leading to obesity.
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U2 - 10.1038/s41366-018-0171-5
DO - 10.1038/s41366-018-0171-5
M3 - Article
C2 - 30082752
AN - SCOPUS:85052324351
VL - 43
SP - 189
EP - 201
JO - International Journal of Obesity
JF - International Journal of Obesity
SN - 0307-0565
IS - 1
ER -