scholarly journals Deficiency of PTP1B in Leptin Receptor-Expressing Neurons Leads to Decreased Body Weight and Adiposity in Mice

Endocrinology ◽  
2012 ◽  
Vol 153 (9) ◽  
pp. 4227-4237 ◽  
Author(s):  
Ryan C. Tsou ◽  
Derek J. Zimmer ◽  
Bart C. De Jonghe ◽  
Kendra K. Bence

Protein tyrosine phosphatase 1B (PTP1B) is a ubiquitously expressed tyrosine phosphatase implicated in the negative regulation of leptin and insulin receptor signaling. PTP1B−/− mice possess a lean metabolic phenotype attributed at least partially to improved hypothalamic leptin sensitivity. Interestingly, mice lacking both leptin and PTP1B (ob/ob:PTP1B−/−) have reduced body weight compared with mice lacking leptin only, suggesting that PTP1B may have important leptin-independent metabolic effects. We generated mice with PTP1B deficiency specifically in leptin receptor (LepRb)-expressing neurons (LepRb-PTP1B−/−) and compared them with LepRb-Cre-only wild-type (WT) controls and global PTP1B−/− mice. Consistent with PTP1B's role as a negative regulator of leptin signaling, our results show that LepRb-PTP1B−/− mice are leptin hypersensitive and have significantly reduced body weight when maintained on chow or high-fat diet (HFD) compared with WT controls. LepRb-PTP1B−/− mice have a significant decrease in adiposity on HFD compared with controls. Notably, the extent of attenuated body weight gain on HFD, as well as the extent of leptin hypersensitivity, is similar between LepRb-PTP1B−/− mice and global PTP1B−/− mice. Overall, these results demonstrate that PTP1B deficiency in LepRb-expressing neurons results in reduced body weight and adiposity compared with WT controls and likely underlies the improved metabolic phenotype of global and brain-specific PTP1B-deficient models. Subtle phenotypic differences between LepRb-PTP1B−/− and global PTP1B−/− mice, however, suggest that PTP1B independent of leptin signaling may also contribute to energy balance in mice.


2011 ◽  
Vol 300 (6) ◽  
pp. E1002-E1011 ◽  
Author(s):  
Bart C. De Jonghe ◽  
Matthew R. Hayes ◽  
Ryoichi Banno ◽  
Karolina P. Skibicka ◽  
Derek J. Zimmer ◽  
...  

The adipose tissue-derived hormone leptin regulates energy balance through catabolic effects on central circuits, including proopiomelanocortin (POMC) neurons. Leptin activation of POMC neurons increases thermogenesis and locomotor activity. Protein tyrosine phosphatase 1B (PTP1B) is an important negative regulator of leptin signaling. POMC neuron-specific deletion of PTP1B in mice results in reduced high-fat diet-induced body weight and adiposity gain due to increased energy expenditure and greater leptin sensitivity. Mice lacking the leptin gene ( ob/ob mice) are hypothermic and cold intolerant, whereas leptin delivery to ob/ob mice induces thermogenesis via increased sympathetic activity to brown adipose tissue (BAT). Here, we examined whether POMC PTP1B mediates the thermoregulatory response of CNS leptin signaling by evaluating food intake, body weight, core temperature (TC), and spontaneous physical activity (SPA) in response to either exogenous leptin or 4-day cold exposure (4°C) in male POMC-Ptp1b-deficient mice compared with wild-type controls. POMC-Ptp1b −/− mice were hypersensitive to leptin-induced food intake and body weight suppression compared with wild types, yet they displayed similar leptin-induced increases in TC. Interestingly, POMC-Ptp1b −/− mice had increased BAT weight and elevated plasma triiodothyronine (T3) levels in response to a 4-day cold challenge, as well as reduced SPA 24 h after cold exposure, relative to controls. These data show that PTP1B in POMC neurons plays a role in short-term cold-induced reduction of SPA and may influence cold-induced thermogenesis via enhanced activation of the thyroid axis.



2006 ◽  
Vol 291 (2) ◽  
pp. R367-R375 ◽  
Author(s):  
Niels Vrang ◽  
Andreas Nygaard Madsen ◽  
Mads Tang-Christensen ◽  
Gitte Hansen ◽  
Philip Just Larsen

The gut hormone peptide YY (PYY) was recently proposed to comprise an endogenous satiety factor. We have studied acute anorectic functions of PYY(3–36) in mice and rats, as well as metabolic effects of chronic PYY(3–36) administration to diet-induced obese (DIO) mice and rats. A single intraperitoneal injection of PYY(3–36) inhibited food intake in mice, but not in rats. We next investigated the effects of increasing doses (100, 300, and 1,000 μg·kg−1·day−1) of PYY(3–36) administered subcutaneously via osmotic minipumps on food intake and body weight in DIO C57BL/6J mice. Whereas only the highest dose (1,000 μg·kg−1·day−1) of PYY(3–36) significantly reduced food intake over the first 3 days, body weight gain was dose dependently reduced, and on day 28 the group treated with 1,000 μg·kg−1·day−1 PYY(3–36) weighed ∼10% less than the vehicle-treated group. Mesenteric, epididymal, retroperitoneal, and inguinal fat pad weight was dose dependently reduced. Subcutaneous administration of PYY(3–36) (250 and 1,000 μg·kg−1·day−1) for 28 days reduced body weight and improved glycemic control in glucose-intolerant DIO rats. Neither 250 nor 1,000 μg/kg PYY(3–36) elicited a conditioned taste aversion in male rats.



2021 ◽  
Author(s):  
Tanja Jene ◽  
Inigo Ruiz de Azua ◽  
Annika Hasch ◽  
Jennifer Klüpfel ◽  
Julia Deuster ◽  
...  

Stress has a major impact on the modulation of metabolism, as previously evidenced by hyperglycemia following chronic social defeat (CSD) stress in mice. Although CSD-triggered metabolic dysregulation might predispose to pre-diabetic conditions, insulin sensitivity remained intact, and obesity did not develop, when animals were fed with a standard diet (SD). Here, we investigated whether a nutritional challenge, a high fat diet (HFD), aggravates the metabolic phenotype, and whether there are particularly sensitive time windows for the negative consequences of HFD exposure. Chronically stressed male mice and controls (CTRL) were kept under (i) SD-conditions, (ii) with HFD commencing post-CSD, or (iii) provided with HFD lasting throughout, and after CSD. Under SD conditions, stress increased glucose levels early post-CSD. Both HFD regimens increased glucose levels in non-stressed mice, but not in stressed mice. Nonetheless, when HFD was provided after CSD, stressed mice did not differ from controls in long-term body weight gain, fat tissue mass and plasma insulin, and leptin levels. In contrast, when HFD was continuously available, stressed mice displayed reduced body weight gain, lowered plasma levels of insulin, and leptin, and reduced white adipose tissue weights as compared to their HFD-treated non-stressed controls. Interestingly, stress-induced adrenal hyperplasia and hypercortisolemia were observed in mice treated with SD and with HFD after CSD, but not in stressed mice exposed to a continuous HFD treatment. The present work demonstrates that CSD can reduce HFD-induced metabolic dysregulation. Hence, HFD during stress may act beneficially, as comfort food, by decreasing stress-induced metabolic demands.



2010 ◽  
Vol 31 (4) ◽  
pp. 600-601 ◽  
Author(s):  
Christa M. Patterson ◽  
Sebastien G. Bouret ◽  
Sunny Park ◽  
Boman G. Irani ◽  
Ambrose A. Dunn-Meynell ◽  
...  

Abstract Because rearing rats in large litters (LLs) protects them from becoming obese, we postulated that LL rearing would protect rats selectively bred to develop diet-induced obesity (DIO) from becoming obese by overcoming their inborn central leptin resistance. Male and female DIO rats were raised in normal litters (10 pups/dam) or LLs (16 pups/dam) and assessed for anatomical, biochemical, and functional aspects of leptin sensitivity at various ages when fed low-fat chow or a 31% fat high-energy (HE) diet. LL rearing reduced plasma leptin levels by postnatal d 2 (P) 2 and body weight gain by P8. At P16, LL DIO neonates had increased arcuate nucleus (ARC) binding of leptin to its extracellular receptors and at P28 an associated increase of their agouti-related peptide and α-MSH axonal projections to the paraventricular nucleus. Reduced body weight persisted and was associated with increased ARC leptin receptor binding and sensitivity to the anorectic effects of leptin, reduced adiposity, and enhanced insulin sensitivity in LL DIO rats fed chow until 10 wk of age. The enhanced ARC leptin receptor binding and reduced adiposity of LL DIO rats persisted after an additional 5 wk on the HE diet. Female LL DIO rats had similar reductions in weight gain on both chow and HE diet vs. normal litter DIO rats. We postulate that LL rearing enhances DIO leptin sensitivity by lowering plasma leptin levels and thereby increasing leptin receptor availability and that this both enhances the ARC-paraventricular nucleus pathway development and protects them from becoming obese.



Endocrinology ◽  
2010 ◽  
Vol 151 (1) ◽  
pp. 143-152 ◽  
Author(s):  
Victoria F. Turek ◽  
James L. Trevaskis ◽  
Barry E. Levin ◽  
Ambrose A. Dunn-Meynell ◽  
Boman Irani ◽  
...  

Abstract The present studies aimed to identify mechanisms contributing to amylin/leptin synergy in reducing body weight and adiposity. We reasoned that if amylin/leptin harnessed complementary neuronal pathways, then in the leptin-sensitive state, amylin should augment leptin signaling/binding and that in the absence of endogenous amylin, leptin signaling should be diminished. Amylin (50 μg/kg, ip) amplified low-dose leptin-stimulated (15 μg/kg, ip) phosphorylated signal transducer and activator of transcription-3 signaling within the arcuate nucleus (ARC) in lean rats. Amylin (50 μg/kg · d) or leptin (125 μg/kg · d) infusion to lean rats decreased 28-d food intake (14 and 10%, respectively), body weight (amylin by 4.3%, leptin by 4.9%), and epididymal fat (amylin by 19%, leptin by 37%). Amylin/leptin co-infusion additively decreased food intake (by 26%) and reduced body weight (by 15%) and epididymal fat (by 78%; all P < 0.05 vs. all groups) in a greater than mathematically additive manner, consistent with synergy. Amylin increased leptin binding within the ventromedial hypothalamus (VMN) by 35% and dorsomedial hypothalamus by 47% (both P < 0.05 vs. vehicle). Amylin/leptin similarly increased leptin binding in the VMN by 40% and ARC by 70% (P < 0.05 vs. vehicle). In amylin-deficient mice, hypothalamic leptin receptor mRNA expression was reduced by 50%, leptin-stimulated phosphorylated signal transducer and activator of transcription-3 within ARC and VMN was reduced by 40%, and responsiveness to leptin’s (1 mg/kg · d for 28 d) weight-reducing effects was attenuated (all P < 0.05 vs. wild-type controls). We suggest that amylin/leptin’s marked weight- and fat-reducing effects are due to activation of intrinsic synergistic neuronal signaling pathways and further point to the integrated neurohormonal therapeutic potential of amylin/leptin agonism in obesity.



2013 ◽  
Vol 305 (9) ◽  
pp. R1076-R1084 ◽  
Author(s):  
Bo Sun ◽  
Nu-Chu Liang ◽  
Erin R. Ewald ◽  
Ryan H. Purcell ◽  
Gretha J. Boersma ◽  
...  

Maternal high-fat (HF) diet has long-term consequences on the metabolic phenotype of the offspring. Here, we determined the effects of postweaning exercise in offspring of rat dams fed HF diet during gestation and lactation. Pregnant Sprague-Dawley rats were maintained on chow or HF diet throughout gestation and lactation. All pups were weaned onto chow diet on postnatal day (PND) 21. At 4 wk of age, male pups were given free access to running wheels (RW) or remained sedentary (SED) for 3 wk, after which all rats remained sedentary, resulting in four groups: CHOW-SED, CHOW-RW, HF-SED, and HF-RW. Male HF offspring gained more body weight by PND7 compared with CHOW pups and maintained this weight difference through the entire experiment. Three weeks of postweaning exercise did not affect body weight gain in either CHOW or HF offspring, but reduced adiposity in HF offspring. Plasma leptin was decreased at the end of the 3-wk running period in HF-RW rats but was not different from HF-SED 9 wk after the exercise period ended. At 14 wk of age, intracerebroventricular injection of leptin suppressed food intake in CHOW-SED, CHOW-RW, and HF-RW, while it did not affect food intake in HF-SED group. At death, HF-RW rats also had higher leptin-induced phospho-STAT3 level in the arcuate nucleus than HF-SED rats. Both maternal HF diet and postweaning exercise had effects on hypothalamic neuropeptide and receptor mRNA expression in adult offspring. Our data suggest that postweaning exercise improves central leptin sensitivity and signaling in this model.



2012 ◽  
Vol 303 (5) ◽  
pp. E644-E651 ◽  
Author(s):  
Bart C. De Jonghe ◽  
Matthew R. Hayes ◽  
Derek J. Zimmer ◽  
Scott E. Kanoski ◽  
Harvey J. Grill ◽  
...  

Leptin regulates energy balance through central circuits that control food intake and energy expenditure, including proopiomelanocortin (POMC) neurons. POMC neuron-specific deletion of protein tyrosine phosphatase 1B (PTP1B) ( Ptpn1 loxP/loxP POMC-Cre), a negative regulator of CNS leptin signaling, results in resistance to diet-induced obesity and improved peripheral leptin sensitivity in mice, thus establishing PTP1B as an important component of POMC neuron regulation of energy balance. POMC neurons are expressed in the pituitary, the arcuate nucleus of the hypothalamus (ARH), and the nucleus of the solitary tract (NTS) in the hindbrain, and it is unknown how each population might contribute to the phenotype of POMC-Ptp1b −/− mice. It is also unknown whether improved leptin sensitivity in POMC-Ptp1b −/− mice involves altered melanocortin receptor signaling. Therefore, we examined the effects of hindbrain administration (4th ventricle) of leptin (1.5, 3, and 6 μg) or the melanocortin 3/4R agonist melanotan II (0.1 and 0.2 nmol) in POMC-Ptp1b −/− (KO) and control PTP1Bfl/fl (WT) mice on food intake, body weight, spontaneous physical activity (SPA), and core temperature (TC). The results show that KO mice were hypersensitive to hindbrain leptin- and MTII-induced food intake and body weight suppression and SPA compared with WT mice. Greater increases in leptin- but not MTII-induced TC were also observed in KO vs. WT animals. In addition, KO mice displayed elevated hindbrain and hypothalamic MC4R mRNA expression. These studies are the first to show that hindbrain administration of leptin or a melanocortin receptor agonist alters energy balance in mice likely via participation of hindbrain POMC neurons.



Endocrinology ◽  
2011 ◽  
Vol 152 (11) ◽  
pp. 4116-4126 ◽  
Author(s):  
Miriam Granado ◽  
Cristina García-Cáceres ◽  
Esther Fuente-Martín ◽  
Francisca Díaz ◽  
Virginia Mela ◽  
...  

In rodents there is a rise in serum leptin levels between postnatal days (PND) 5 and 14, with this neonatal leptin surge reported to modulate the maturation of hypothalamic circuits involved in appetite regulation. We hypothesized that acute changes in neonatal leptin levels have different long-term metabolic effects depending on how and when this surge is modified. To advance the timing of the normal leptin peak, male Wistar rats were injected with leptin (sc, 3 μg/g) on PND 2. To ablate the leptin peak on PND 10, a pegylated leptin antagonist (sc, 9 μg/g) was injected. Controls received vehicle. All rats were allowed to eat ad libitum until PND 150. Increased leptin on PND 2 reduced food intake (P < 0.01) after 3 months of age with no effect on body weight. Levels of total ghrelin were reduced (P < 0.001) and acylated ghrelin increased (P < 0.05), with no other modifications in metabolic hormones. In contrast, treatment with the leptin antagonist on PND 9 did not affect food intake but reduced body weight beginning around PND 60 (P < 0.02). This was associated with a reduction in fat mass, insulin (P < 0.01), and leptin (P < 0.007) levels and an increase in testosterone levels (P < 0.01). Hypothalamic neuropeptide Y (P < 0.05) and leptin receptor (P < 0.005) mRNA levels were reduced, whereas mRNA levels for uncoupling protein 2 (P < 0.005) were increased in visceral fat, which may indicate an increase in energy expenditure. In conclusion, acute changes in neonatal leptin levels induce different metabolic profiles depending on how and when leptin levels are modified.





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