Piperonal attenuates visceral adiposity in mice fed a high-fat diet: potential involvement of the adenylate cyclase-protein kinase A dependent pathway

2017 ◽  
Vol 61 (11) ◽  
pp. 1601124 ◽  
Author(s):  
Songyi Chu ◽  
Vikram P. Narayan ◽  
Mi-Kyung Sung ◽  
Taesun Park
Keyword(s):  
Protein Kinase ◽  
Adenylate Cyclase ◽  
Protein Kinase A ◽  
High Fat Diet ◽  
Visceral Adiposity ◽  
High Fat ◽  
Dependent Pathway ◽  
Kinase A

scholarly journals B56α/Protein Phosphatase 2A Inhibits Adipose Lipolysis in High-Fat Diet-Induced Obese Mice

Endocrinology ◽  
2010 ◽  
Vol 151 (8) ◽  
pp. 3624-3632 ◽  
Author(s):  
Brice P. Kinney ◽  
Liping Qiao ◽  
Justin M. LeVaugh ◽  
Jianhua Shao
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Protein Phosphatase ◽  
High Fat Diet ◽  
Protein Phosphatase 2A ◽  
High Fat ◽  
Protein Levels ◽  
Epididymal Fat ◽  
Phosphatase 2A ◽  
Kinase A

Lipolysis and lipogenesis are two opposite processes that control lipid storage in adipocytes. Impaired adipose lipolysis has been observed in both obese human subjects and animal models. This study investigated the mechanisms underlying impaired adipose lipolysis in a high-fat diet-induced obese (DIO) mouse model. DIO models were created using male C57BL/6 mice. Our results show that β3 adrenergic receptor-specific agonist BRL37344 induced adipose lipolysis was significantly blunted in DIO mice. The levels of Ser660 phosphorylation of hormone-sensitive lipase (HSL) were significantly decreased in the epididymal fat of DIO mice. However, protein levels of HSL, adipose triglyceride lipase and its coactivator comparative gene identification-58 were similar between DIO and control mice. It is known that upon lipolytic hormone stimulation, protein kinase A phosphorylates HSL Ser660 and activates HSL, whereas protein phosphatase 2A (PP2A) dephosphorylates and inactivates HSL. Interestingly, our study shows that high-fat feeding did not alter epididymal fat cAMP and protein kinase A protein levels but significantly increased the expression of the α-isoform of PP2A regulatory subunit B′ (B56α). To study the role of B56α in obesity-associated lipolytic defect, B56α was overexpressed or knocked down by adenovirus-mediated gene transduction in cultured 3T3-L1CARΔ1 adipocytes. Overexpression of B56α significantly decreased HSL Ser660 phosphorylation. In contrast, knocking down B56α increased hormone-stimulated HSL activation and lipolysis in mature 3T3-L1CARΔ1 adipocytes. These results strongly suggest that elevated B56α/PP2A inhibits HSL and lipolysis in white adipose tissue of DIO mice.

scholarly journals Durable islet effects on insulin secretion and protein kinase A expression following exendin-4 treatment of high-fat diet-fed mice

2007 ◽  
Vol 40 (2) ◽  
pp. 93-100 ◽  
Author(s):  
Maria Sörhede Winzell ◽  
Bo Ahrén
Keyword(s):  
Insulin Secretion ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
High Fat Diet ◽  
Caspase 3 ◽  
Receptor Activation ◽  
High Fat ◽  
Β Cell ◽  
Once Daily ◽  
Kinase A

Glucagon-like peptide 1 (GLP-1) augments glucose-stimulated insulin secretion (GSIS) through cAMP-induced activation of protein kinase A (PKA), and stimulates β-cell proliferation and reduces β-cell apoptosis in rodent islets. This study explored islet GSIS, PKA expression, and markers of apoptosis (caspase 3/7 activity) and proliferation (PKBα and pancreatic and duodenal homeobox gene 1, Pdx-1) after 2 weeks of treatment with the GLP-1 receptor agonist exendin-4 (2 nmol/kg once daily) in female mice with high-fat diet-induced insulin resistance (HFD; 58% fat by energy). Islets were isolated 20 h after the last exendin-4 injection, when effects of circulating exendin-4 had vanished. The glucose responsiveness in islets from HFD-fed mice at 8.3 mM glucose was reduced compared with islets from control mice fed a normal diet due to increased basal insulin secretion. However, GSIS increased in islets from HFD-fed exendin-4-treated animals (0.124±0.012 ng/h per islet in HFD-Ex-4 versus 0.062±0.010 in HFD, P=0.006). Furthermore, the insulin response to forskolin was increased (2.7±0.3 in HFD-Ex-4 versus 2.0±0.2 ng/h per islet in HFD, P=0.011) and PKAcat expression was increased, while PKAreg was reduced in islets from exendin-4-treated mice. In contrast, protein expression of PKBα, Pdx-1, and caspase 3/7 activity was not affected by exendin-4 treatment. We conclude that GLP-1 receptor activation in HFD-fed mice has durable effects on GSIS, in association with augmented signaling through the PKA pathway. These effects are seen beyond those induced by circulating exendin-4 already after 2 weeks of once-daily treatment in mice, whereas markers for islet proliferation and apoptosis were unaffected by this treatment.

scholarly journals High-fat diet induces protein kinase A and G-protein receptor kinase phosphorylation of β2 -adrenergic receptor and impairs cardiac adrenergic reserve in animal hearts

2017 ◽  
Vol 595 (6) ◽  
pp. 1973-1986 ◽  
Author(s):  
Qin Fu ◽  
Yuting Hu ◽  
Qingtong Wang ◽  
Yongming Liu ◽  
Ning Li ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
High Fat Diet ◽  
Adrenergic Receptor ◽  
Receptor Kinase ◽  
High Fat ◽  
Protein Receptor ◽  
Β2 Adrenergic Receptor ◽  
Kinase Phosphorylation ◽  
Kinase A

scholarly journals Pituitary adenylate cyclase activating polypeptide as a novel hypophysiotropic factor in fish

2000 ◽  
Vol 78 (3) ◽  
pp. 329-343 ◽  
Author(s):  
Anderson OL Wong ◽  
Wen Sheng Li ◽  
Eric KY Lee ◽  
Mei Yee Leung ◽  
Lai Yin Tse ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Adenylate Cyclase ◽  
Protein Kinase A ◽  
Anterior Pituitary ◽  
Kinase C ◽  
Pituitary Adenylate Cyclase ◽  
Pacap Receptors ◽  
Kinase A

Pituitary adenylate cyclase activating polypeptide (PACAP) is a novel member of the secretin-glucagon peptide family. In mammals, this peptide has been located in a wide range of tissues and is involved in a variety of biological functions. In lower vertebrates, especially fish, increasing evidence suggests that PACAP may function as a hypophysiotropic factor regulating pituitary hormone secretion. PACAP has been identified in the brain-pituitary axis of representative fish species. The molecular structure of fish PACAP is highly homologous to mammalian PACAP. The prepro-PACAP in fish, however, is distinct from that of mammals as it also contains the sequence of fish GHRH. In teleosts, the anterior pituitary is under direct innervation of the hypothalamus and PACAP nerve fibers have been identified in the pars distalis. Using the goldfish as a fish model, mRNA transcripts of PACAP receptors, namely the PAC1 and VPAC1 receptors, have been identified in the pituitary as well as in various brain areas. Consistent with the pituitary expression of PACAP receptors, PACAP analogs are effective in stimulating growth hormone (GH) and gonadotropin (GTH)-II secretion in the goldfish both in vivo and in vitro. The GH-releasing action of PACAP is mediated via pituitary PAC1 receptors coupled to the adenylate cyclase-cAMP-protein kinase A and phospholipase C-IP3-protein kinase C pathways. Subsequent stimulation of Ca2+ entry through voltage-sensitive Ca2+ channels followed by activation of Ca2+-calmodulin protein kinase II is likely the downstream mechanism mediating PACAP-stimulated GH release in goldfish. Although the PACAP receptor subtype(s) and the associated post-receptor signaling events responsible for PACAP-stimulated GTH-II release have not been characterized in goldfish, these findings support the hypothesis that PACAP is produced in the hypothalamus and delivered to the anterior pituitary to regulate GH and GTH-II release in fish.Key words: PACAP, VIP, PAC1 receptor, VPAC1 receptor, VPAC2 receptor, growth hormone, gonadotropin-II, cAMP, protein kinase A, protein kinase C, calcium, pituitary cells, goldfish, and teleost.

scholarly journals Platelet-derived Growth Factor Stimulates Protein Kinase A through a Mitogen-activated Protein Kinase-dependent Pathway in Human Arterial Smooth Muscle Cells

1996 ◽  
Vol 271 (1) ◽  
pp. 505-511 ◽  
Author(s):  
Lee M. Graves ◽  
Karin E. Bornfeldt ◽  
Jaspreet S. Sidhu ◽  
Gretchen M. Argast ◽  
Elaine W. Raines ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Mitogen Activated Protein Kinase ◽  
Platelet Derived Growth Factor ◽  
Mitogen Activated Protein ◽  
Arterial Smooth Muscle Cells ◽  
Dependent Pathway ◽  
Kinase A

Carbenoxolone inhibits junctional transfer and upregulates connexin43 expression by a protein kinase A-dependent pathway

2006 ◽  
Vol 98 (6) ◽  
pp. 1543-1551 ◽  
Author(s):  
G.D. Vivek Sagar ◽  
D.M. Larson
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Dependent Pathway ◽  
Kinase A
Sign in / Sign up

Export Citation Format

Share Document