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. 2013 Sep 3;18(3):431-44.
doi: 10.1016/j.cmet.2013.08.004.

Leptin engages a hypothalamic neurocircuitry to permit survival in the absence of insulin

Teppei Fujikawa  1 , Eric D Berglund, Vishal R Patel, Giorgio Ramadori, Claudia R Vianna, Linh Vong, Fabrizio Thorel, Simona Chera, Pedro L Herrera, Bradford B Lowell, Joel K Elmquist, Pierre Baldi, Roberto Coppari
Affiliations

Leptin engages a hypothalamic neurocircuitry to permit survival in the absence of insulin

Teppei Fujikawa et al. Cell Metab. .

Abstract

The dogma that life without insulin is incompatible has recently been challenged by results showing the viability of insulin-deficient rodents undergoing leptin monotherapy. Yet, the mechanisms underlying these actions of leptin are unknown. Here, the metabolic outcomes of intracerebroventricular (i.c.v.) administration of leptin in mice devoid of insulin and lacking or re-expressing leptin receptors (LEPRs) only in selected neuronal groups were assessed. Our results demonstrate that concomitant re-expression of LEPRs only in hypothalamic γ-aminobutyric acid (GABA) and pro-opiomelanocortin (POMC) neurons is sufficient to fully mediate the lifesaving and antidiabetic actions of leptin in insulin deficiency. Our analyses indicate that enhanced glucose uptake by brown adipose tissue and soleus muscle, as well as improved hepatic metabolism, underlies these effects of leptin. Collectively, our data elucidate a hypothalamic-dependent pathway enabling life without insulin and hence pave the way for developing better treatments for diseases of insulin deficiency.

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Figures

Figure 1
Figure 1. icv leptin administration reverses lethality and improves hyperglycemia caused by complete insulin deficiency
(A) Experimental design using RIP-DTR mice (Thorel et al., 2010). Leptin (25 ng/hour) or placebo (phosphate-buffered saline; PBS) was intracerebroventricularly (icv) administered starting at day 0 in DT-icv-leptin or DT-icv-placebo mice, respectively. DT-icv-leptin and DT-icv-placebo mice were rendered insulin deficient by intraperitoneal (ip) diphtheria toxin (DT) administration at day 0, 3, and 5. Age-matched, non-diabetic controls were used to gather parameters in surgically- and DT-untreated normal mice (normal group). (B) Kaplan-Meier survival analyses were performed on DT-icv-leptin and DT-icv-placebo mice; Statistical analyses were done using by Gehan-Breslow-Wilcoxon Test. ***P<0.001 versus DT-icv-placebo mice (numbers of mice at day 0 of DT-icv-leptin and DT-icv-placebo were 8 and 6, respectively). (C) Glucose levels in the blood, body weight, food intake, (D) glucagon in the plasma, (E) hepatic protein levels of pCREB and PEPCK, (F) glycogen in the liver, (G) insulin levels in the plasma and whole pancreas and (H) representative distribution of cells expressing insulin (green) and glucagon (red) in the pancreas of DT-icv-placebo, DT-icv-leptin and normal mice. Statistical analyses were done using one-way ANOVA (Tukey's Multiple Comparison Test). Values are mean ± S.E.M. (n = 4–6). ***P<0.001, **P<0.01, *P<0.05 versus DT-icv-placebo mice. ND = below the threshold of detection. Scale bar size = 100 μm. See also Figure S1
Figure 2
Figure 2. LEPRs in POMC neurons are required to mediate a marginal component of anti-diabetic action of leptin in the context of insulin deficiency
(A) Experimental design using streptozotocin (STZ)-treated mice (Fujikawa et al., 2010). To induce insulin deficiency, STZ was ip administered to mice lacking LEPRs selectively in POMC neurons (Pomc-Cre;Leprflox/flox), or SF1 neurons (Sf1-Cre;Leprflox/flox), and littermate control mice (Leprflox/flox). Leptin (25 ng/hour) was delivered icv to Pomc-Cre;Leprflox/flox, Sf1-Cre;Leprflox/flox and Leprflox/flox mice (STZ-Pomc-Cre;Leprflox/flox-icv-leptin, STZ-Sf1-Cre;Leprflox/flox-icv-leptin and STZ-Leprflox/flox-icv-leptin group, respectively). Placebo (PBS) was delivered icv to Leprflox/flox mice (STZ-Leprflox/flox-icv-placebo). (B) Glucose levels in the blood, body weight, food intake and insulin levels in the plasma of STZ-Leprflox/flox-icv-placebo, STZ-Sf1-Cre;Leprflox/flox-icv-leptin, STZ-Pomc-Cre;Leprflox/flox-icv-leptin and STZ-Leprflox/flox-icv-leptin mice. (C) Kaplan-Meier survival analyses were performed on STZ-Leprflox/flox-icv-placebo, STZ-Pomc-Cre;Leprflox/flox-icv-leptin and STZ-Leprflox/flox-icv-leptin mice; Statistical analyses were done using by Log-rank Test (numbers of mice at day of all group were 5), glucose levels in the blood, food intake and (D) glucagon levels in the plasma of STZ-Leprflox/flox-icv-placebo, STZ-Pomc-Cre;Leprflox/flox-icv-leptin and STZ-Leprflox/flox-icv-leptin mice. (E) Kaplan-Meier survival analyses were performed on DT-Leprflox/flox-icv-placebo, DT-Pomc-Cre;Leprflox/flox-icv-leptin and DT-Leprflox/flox-icv-leptin mice; Statistical analyses were done using Log-rank Test (among all groups) followed by Gehan-Breslow-Wilcoxon Test (each group versus DT-Leprflox/flox-icv-placebo). ***P<0.001. (numbers of mice at day 0 of DT-Leprflox/flox-icv-placebo, DT-Pomc-Cre;Leprflox/flox-icv-leptin and DT-Leprflox/flox-icv-leptin were 8, 9 and 6, respectively). Glucose levels in the blood, food intake and (F) glucagon levels in the DT-Leprflox/flox-icv-placebo, DT-Pomc-Cre;Leprflox/flox-icv-leptin and DT-Leprflox/flox-icv-leptin mice. Harvested day means the date of death of succumbed DT-Leprflox/flox-icv-placebo mice and 25 days after icv leptin administration in DT-Pomc-Cre;Leprflox/flox-icv-leptin and DT-Leprflox/flox-icv-leptin mice. Statistical analyses were done using one-way ANOVA (Tukey's or Dunnett's Multiple Comparison Test). Values are mean ± S.E.M. (n = 3–9). ***P<0.001, **P<0.01 versus STZ- or DT-Leprflox/flox-icv-placebo or STZ- or DT-Pomc-Cre;Leprflox/flox-icv-leptin mice. †††P<0.001, ††P<0.01, †P<0.05 versus STZ- or DT-Leprflox/flox-icv-leptin. ND = below the threshold of detection. See also Figure S2
Figure 3
Figure 3. LEPRs in POMC neurons are notsufficient to mediate the anti-diabetic action of leptin in the context of insulin deficiency
(A) Kaplan-Meier survival analyses were performed on insulin-deficient mice expressing LEPRs selectively in POMC neurons, LEPR-intact control (Lepr+/+ and Pomc-Cre;Lepr+/+) and LEPR-null littermates that received icv leptin (25 ng/hour) administration (DT-Pomc-Cre;LeprTB/TB-icv-leptin, DT-icv-leptin, DT-LeprTB/TB-icv-leptin mice, respectively); Statistical analyses were done using Log-rank Test (among all groups) followed by Gehan-Breslow-Wilcoxon Test (each group versus DT-LeprTB/TB-icv-leptin). ***P<0.001. (numbers of mice at day 0 of DT-LeprTB/TB-icv-leptin, DT-Pomc-Cre;LeprTB/TB-icv-leptin and DT were 11, 8 and 5, respectively). (B) Glucose levels in the blood, body weight, insulin levels in the plasma and (C) representative distribution of cells expressing phosphorylated STAT3 (pSTAT3) in the mediobasal hypothalamus of DT-LeprTB/TB-icv-leptin, DT-Pomc-Cre;LeprTB/TB-icv-leptin and DT-icv-leptin mice. Harvested day means the date of death of succumbed DT-Pomc-Cre;LeprTB/TB-icv-leptin and DT-icv-leptin mice and 25 days after icv leptin administration in DT-icv-leptin mice. Statistical analyses were done using one-way ANOVA (Tukey's Multiple Comparison Test). Values are mean ± S.E.M. (n = 5–11). ***P<0.001, **P<0.01 versus DT-LeprTB/TB-icv-leptin. ND = below the threshold of detection. Scale bar size = 100 μ m. ARC, arcuate nucleus; VMH, ventromedial hypothalamic nucleus. See also Figure S3
Figure 4
Figure 4. LEPRs in GABAergic neurons are sufficient to largely mediate the survival and anti-diabetic action of leptin in the context of insulin deficiency
(A) Kaplan-Meier survival analyses were performed on DT-treated mice expressing LEPRs selectively in GABAergic neurons that received icv leptin (25 ng/hour) administration (DT-VGAT-icv-leptin), or placebo (PBS) administration (DT-VGAT-icv-placebo) and LEPR-intact control (composed of Vgat-ires-Cre;Lepr+/+;RIP-DTR and Lepr+/+;RIP-DTR mice) littermate mice that received icv leptin administration (DT-icv-leptin); Statistical analyses were done using Log-rank Test (among all groups) followed by Gehan-Breslow-Wilcoxon Test (compared each group versus DT-VGAT-icv-placebo). ***P<0.001. (numbers of mice at day 0 of DT-VGAT-icv-placebo, DT-VGAT-icvleptin and DT-icv-leptin were 5, 12 and 8, respectively). (B) Glucose levels in the blood, and body weight, and (C) food intake (D) glucagon levels in the plasma in DT-VGAT-icv-placebo, DT-VGAT-icv-leptin (non-survivors), DT-VGAT-icv-leptin (survivors), and DT-icv-leptin mice. (E) Representative distribution of cells expressing phosphorylated STAT3 (a read out of leptin-responsive neurons) in the lateral hypothalamic area (LHA), hypothalamic arcuate nucleus (ARC) and dorsomedial nucleus (DMH) of DT-VGAT-icv-placebo, DT-VGAT-icv-leptin and DT-icv-leptin mice. Anatomical location of LHA, ARC and DMH is shown in red-colored, dashed-line boxed area in top panels (Franklin and Paxinos, 2008). Statistical analyses were done using one-way ANOVA (Dunnett's Multiple Comparison Test). Values are mean ± S.E.M. (n = 3–12). Scale bar size = 100 μm. †††P<0.001, ††P<0.01, †P<0.05 versus DT-icv-leptin. See also Figure S4
Figure 5
Figure 5. LEPRs in GABAergic and POMC neurons are sufficient to fully mediate the anti-diabetic action of leptin in the context of insulin deficiency
(A) Kaplan-Meier survival analyses were performed on DT-treated mice expressing LEPRs selectively in both GABAergic and POMC neurons (Vgat-ires-Cre;Pomc-Cre;LeprTB/TB;RIP-DTR mice), GABAergic neurons (Vgat-ires-Cre;LeprTB/TB;RIP-DTR mice) and LEPR-intact control (composed of Vgat-ires-Cre; Pomc-Cre;Lepr+/+;RIP-DTR, Vgat-ires-Cre;Lepr+/+;RIP-DTR, Pomc-Cre;Lepr+/+;RIP-DTR and Lepr+/+;RIP-DTR mice) mice that received icv leptin (25 ng/hour) administration (DT-VGAT-POMC-icv-leptin, DT-VGAT-icv-leptin and DT-icv-leptin); Statistical analyses were done using by Log-rank Test (numbers of mice at day 0 of DT-VGAT-icv-leptin, DT-VGAT-POMC-icv-leptin and DT-icv-leptin were 8, 7 and 9, respectively). (B) Glucose levels in the blood of DT-VGAT-icv-leptin (non-survivors), DT-VGAT-icv-leptin (survivors), VGAT-POMC-icv-leptin and DT-icv-leptin and (C) glucagon levels in the plasma in DT-VGAT-icv-leptin (survivors), DT-VGAT-POMC-icv-leptin and DT-icv-leptin at 25 days. Statistical analyses were done using one-way ANOVA (Dunnett's Multiple Comparison Test). Values are mean ± S.E.M. (n = 3–9). ††P<0.05, †P<0.05 versus DT-icv-leptin.
Figure 6
Figure 6. Leptin administration induces glucose uptake in soleus and iBAT of insulin-deficient mice
(A) Glucose level in the blood of insulin-deficient β-less mice (that do not express any types of β-adrenergic receptors) and their wild-type controls that received icv leptin (25 ng/hour) administration (STZ-β-less-icv-leptin and STZ-wild-type-icv-leptin groups, respectively). Insulin deficiency was induced by administration of STZ as shown in Figure 2. (B) Experimental design and (C) glucose level in the blood of STZ-treated FBV/NJ mice that received icv administration of leptin (25 ng/hour) followed by administrations of β-adrenergic-receptor blocker timolol (1 mg/kg BW) or placebo (0.9% saline solution). Mice were injected ip twice a day from day 7 up to day 9 and one time 2 hours before sacrifice. (D) Experimental design of assessment of basal glucose utilization. The experiment was carried out 10 days after icv administration as described in Figure 1A. (E) Glucose utilization levels in soleus muscle, gastrocnemius muscle, vastus muscle, interscapular brown adipose tissue and brain of DT-icv-leptin, DT-icv-placebo and normal mice. Values are mean ± S.E.M. (n = 4–6). Statistical analyses were done using unpaired t-test or one-way ANOVA (Tukey's Multiple Comparison Test) *P<0.05 versus DT-icv-placebo mice. See also Figure S5 and Table S1 and S2.
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Comment in

  • Leptin, GABA, and glucose control.
    Kahn BB, Minokoshi Y. Kahn BB, et al. Cell Metab. 2013 Sep 3;18(3):304-6. doi: 10.1016/j.cmet.2013.08.015. Cell Metab. 2013. PMID: 24011066 Free PMC article.

References

    1. Bachman ES, Dhillon H, Zhang CY, Cinti S, Bianco AC, Kobilka BK, Lowell BB. betaAR signaling required for diet-induced thermogenesis and obesity resistance. Science. 2002;297:843–845. - PubMed
    1. Balthasar N, Coppari R, McMinn J, Liu SM, Lee CE, Tang V, Kenny CD, McGovern RA, Chua SC, Jr., Elmquist JK, et al. Leptin receptor signaling in POMC neurons is required for normal body weight homeostasis. Neuron. 2004;42:983–991. - PubMed
    1. Berglund ED, Vianna CR, Donato J, Jr., Kim MH, Chuang JC, Lee CE, Lauzon DA, Lin P, Brule LJ, Scott MM, et al. Direct leptin action on POMC neurons regulates glucose homeostasis and hepatic insulin sensitivity in mice. The Journal of clinical investigation. 2012;122:1000–1009. - PMC - PubMed
    1. Butler PC, Meier JJ, Butler AE, Bhushan A. The replication of beta cells in normal physiology, in disease and for therapy. Nature clinical practice Endocrinology & metabolism. 2007;3:758–768. - PubMed
    1. Choi YH, Fujikawa T, Lee J, Reuter A, Kim KW. Revisiting the Ventral Medial Nucleus of the Hypothalamus: The Roles of SF-1 Neurons in Energy Homeostasis. Frontiers in neuroscience. 2013;7:71. - PMC - PubMed

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