scholarly journals Impaired CNS Leptin Action Is Implicated in Depression Associated with Obesity

Endocrinology ◽  
2011 ◽  
Vol 152 (7) ◽  
pp. 2634-2643 ◽  
Author(s):  
Nobuko Yamada ◽  
Goro Katsuura ◽  
Yukari Ochi ◽  
Ken Ebihara ◽  
Toru Kusakabe ◽  
...  
Keyword(s):  
Neurotrophic Factor ◽  
High Fat Diet ◽  
Control Diet ◽  
Preference Test ◽  
Antidepressant Activity ◽  
Brain Derived Neurotrophic Factor ◽  
Epidemiological Studies ◽  
High Fat ◽  
Depressive Behavior ◽  
Sucrose Preference Test

Recent epidemiological studies indicate that obesity increases the incidence of depression. We examined the implication of leptin for obesity-associated depression. Leptin induced antidepressive behavior in normal mice in a forced swimming test (FST), and leptin-overexpressing transgenic mice with hyperleptinemia exhibited more antidepressive behavior in the FST than nontransgenic mice. In contrast, leptin-deficient ob/ob mice showed more severe depressive behavior in the FST than normal mice, and leptin administration substantially ameliorated this depressive behavior. Diet-induced obese (DIO) mice fed a high-fat diet showed more depressive behavior in the FST and in a sucrose preference test compared with mice fed a control diet (CD). In DIO mice, leptin induced neither antidepressive action nor increment of the number of c-Fos immunoreactive cells in the hippocampus. Diet substitution from high-fat diet to CD in DIO mice ameliorated the depressive behavior and restored leptin-induced antidepressive action. Brain-derived neurotrophic factor concentrations in the hippocampus were significantly lower in DIO mice than in CD mice. Leptin administration significantly increased hippocampal brain-derived neurotrophic factor concentrations in CD mice but not in DIO mice. The antidepressant activity of leptin in CD mice was significantly attenuated by treatment with K252a. These findings demonstrated that leptin induces an antidepressive state, and DIO mice, which exhibit severe depressive behavior, did not respond to leptin in both the FST and the biochemical changes in the hippocampus. Thus, depression associated with obesity is due, at least in part, to impaired leptin activity in the hippocampus.

scholarly journals Chronic administration of brain-derived neurotrophic factor in the hypothalamic paraventricular nucleus reverses obesity induced by high-fat diet

2010 ◽  
Vol 298 (5) ◽  
pp. R1320-R1332 ◽  
Author(s):  
ChuanFeng Wang ◽  
Rebecca J. Godar ◽  
Charles J. Billington ◽  
Catherine M. Kotz
Keyword(s):  
Body Weight ◽  
Body Fat ◽  
Paraventricular Nucleus ◽  
Neurotrophic Factor ◽  
High Fat Diet ◽  
Control Diet ◽  
Brain Derived Neurotrophic Factor ◽  
Hypothalamic Paraventricular Nucleus ◽  
High Fat ◽  
Metabolic Indices

An acute injection of brain-derived neurotrophic factor (BDNF) in the hypothalamic paraventricular nucleus (PVN) reduces body weight by decreasing feeding and increasing energy expenditure (EE), in animals on standard laboratory chow. Animals have divergent responses to a high-fat diet (HFD) exposure, with some developing obesity and others remaining lean. In the current study, we tested two hypotheses: 1) BDNF in the PVN reverses HFD-induced obesity, and 2) animals with higher body fat have a greater physiological response to BDNF than those with less body fat. Eighty-four 10-wk old rats were allowed HFD ad libitum for 9 wk and then prepared with bilateral PVN cannulas. Animals were then divided into tertiles based on their body fat rank: high, intermediate, and low (H, I, and L). Each group was further divided into 2 subgroups and then PVN injected with BDNF or control (artificial cerebrospinal fluid, aCSF) every other day for 3 wk. Energy intake (EI), body weight, and body composition were measured. At study's end, rats were killed to allow measurement of other metabolic indices. In parallel, another 12 rats were fed control diet (CD), PVN-cannulated and injected with aCSF. HFD exposure induced obesity, particularly in the H body fat group, with a significant increase in EI, body weight, fat mass, liver size, and serum glucose, triglycerides, insulin, and leptin. BDNF significantly reduced EI, body weight, body fat, lean mass, and serum metabolic indices. These BDNF effects were greatest in the H body fat group. These data indicate that BDNF reduced HFD-induced obesity and metabolic syndrome-like measures, and the animals with the most body fat had the most significant response to BDNF.

Influence of a high-fat diet on brain-derived neurotrophic factor (BDNF)

Appetite ◽  
2008 ◽  
Vol 51 (2) ◽  
pp. 412
Author(s):  
N. Zeeni ◽  
C. Chaumontet ◽  
E. Moyse ◽  
N. Darcel ◽  
C. Tardivel ◽  
...  
Keyword(s):  
Neurotrophic Factor ◽  
High Fat Diet ◽  
Brain Derived Neurotrophic Factor ◽  
High Fat

scholarly journals Insulin promotes proliferation and fibrosing responses in activated pancreatic stellate cells

2016 ◽  
Vol 311 (4) ◽  
pp. G675-G687 ◽  
Author(s):  
Jiayue Yang ◽  
Richard T. Waldron ◽  
Hsin-Yuan Su ◽  
Aune Moro ◽  
Hui-Hua Chang ◽  
...  
Keyword(s):  
High Fat Diet ◽  
Pancreatic Beta Cells ◽  
Control Diet ◽  
Stellate Cells ◽  
Epidemiological Studies ◽  
Kinase Domain ◽  
Receptor Expression ◽  
Pancreatic Stellate Cells ◽  
High Fat ◽  
High Concentrations

Epidemiological studies support strong links between obesity, diabetes, and pancreatic disorders including pancreatitis and pancreatic adenocarcinoma (PDAC). Type 2 diabetes (T2DM) is associated with insulin resistance, hyperglycemia, and hyperinsulinemia, the latter due to increased insulin secretion by pancreatic beta-cells. We reported that high-fat diet-induced PDAC progression in mice is associated with hyperglycemia, hyperinsulinemia, and activation of pancreatic stellate cells (PaSC). We investigated here the effects of high concentrations of insulin and glucose on mouse and human PaSC growth and fibrosing responses. We found that compared with normal, pancreata from T2DM patients displayed extensive collagen deposition and activated PaSC in islet and peri-islet exocrine pancreas. Mice fed a high-fat diet for up to 12 mo similarly displayed increasing peri-islet fibrosis compared with mice fed control diet. Both quiescent and activated PaSC coexpress insulin (IR; mainly A type) and IGF (IGF-1R) receptors, and both insulin and glucose modulate receptor expression. In cultured PaSC, insulin induced rapid tyrosine autophosphorylation of IR/IGF-1R at specific kinase domain activation loop sites, activated Akt/mTOR/p70S6K signaling, and inactivated FoxO1, a transcription factor that restrains cell growth. Insulin did not promote activation of quiescent PaSC in either 5 mM or 25 mM glucose containing media. However, in activated PaSC, insulin enhanced cell proliferation and augmented production of extracellular matrix proteins, and these effects were abolished by specific inhibition of mTORC1 and mTORC2. In conclusion, our data support the concept that increased local glucose and insulin concentrations associated with obesity and T2DM promote PaSC growth and fibrosing responses.

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