Early leptin blockade predisposes fat-fed rats to overweight and modifies hypothalamic microRNAs

Abstract

Perinatal leptin impairment has long-term consequences on energy homeostasis leading to body weight gain. The underlying mechanisms are still not clearly established. We aimed to analyze the long-term effects of early leptin blockade. In this study, newborn rats received daily injection of a pegylated rat leptin antagonist (pRLA) or saline from day 2 (d2) to d13 and then body weight gain, insulin/leptin sensitivity, and expression profile of microRNAs (miRNAs) at the hypothalamic level were determined at d28, d90, or d153 (following 1 month of high-fat diet (HFD) challenge). We show that pRLA treatment predisposes rats to overweight and promotes leptin/insulin resistance in both hypothalamus and liver at adulthood. pRLA treatment also modifies the hypothalamic miRNA expression profile at d28 leading to the upregulation of 34 miRNAs and the downregulation of four miRNAs. For quantitative RT-PCR confirmation, we show the upregulation of rno-miR-10a at d28 and rno-miR-200a, rno-miR-409-5p, and rno-miR-125a-3p following HFD challenge. Finally, pRLA treatment modifies the expression of genes involved in energy homeostasis control such as UCPs and AdipoRs. In pRLA rat muscle, Ucp2/3 and Adipor1/r2 are upregulated at d90. In liver, pRLA treatment upregulates Adipor1/r2 following HFD challenge. These genes are known to be involved in insulin resistance and type 2 diabetes. In conclusion, we demonstrate that the impairment of leptin action in early life promotes insulin/leptin resistance and modifies the hypothalamic miRNA expression pattern in adulthood, and finally, this study highlights the potential link between hypothalamic miRNA expression pattern and insulin/leptin responsiveness.

Pegylated leptin antagonist with strong orexigenic activity in mice is not effective in chickens

“…To determine whether our well-established leptin antagonist (Benoit et al, 2013;Chapnik et al, 2013;Niv-Spector et al, 2012;Shpilman et al, 2011), which blocks mammalian LEPRs, also blocks the cLEPR, we used our previously described leptin bioassay in HEK-293 cells (Hen et al, 2008;Marikovsky et al, 2002;Yosefi et al, 2010) (Fig. 1).…”

“…To explore the leptin antagonist's potential to induce appetite and enhance body growth rate in chickens, as we previously showed in mice (Benoit et al, 2013;Chapnik et al, 2013;Elinav et al, 2009;Niv-Spector et al, 2012;Niv-Spector et al, 2010;Shpilman et al, 2011), lean male chickens at 2 weeks of age were subjected to daily administration of the leptin antagonist. As demonstrated in Fig.…”

Milk-soluble formula increases food intake and reduces Il6 expression in elderly rat hypothalami

“…Total RNA was prepared for quantitative RT-PCR (qRT-PCR) as previously described (Benoit et al 2013). Briefly, frozen samples of hypothalamus, liver, and adipose tissue were homogenized using a tissue homogenizer (Precellys 24), and RNA was extracted with TRIzol LS reagent (Invitrogen) according to the manufacturer's instructions.…”

MicroRNAs in the Hypothalamus

“…Further evidence for the involvement of miRNA and the hypothalamic control of energy balance comes from a study showing that impairment of leptin action in early life using a pegylated leptin antagonist predisposes fat-fed rats to overweight, promotes insulin/leptin resistance and modifies hypothalamic miRNA at adulthood [54]. The treatment resulted in the particular upregulation of 34 miRNAs and the downregulation of 4 miRNAs of a total of 524 mature rat miRNAs [54].…”