h-89 and maxadilan-protein--insect

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a structurally endogenous peptide with many biological roles. However, little is known about its presence or effects in human adipose-derived stem cells (hADSCs). In this study, the expression of PACAP type I receptor (PAC1R) was first confirmed in hADSCs. Maxadilan, a specific agonist of PAC1R, could increase hADSC proliferation as determined by Cell Counting Kit-8 and cell cycle analysis and promote migration as shown in wound-healing assays. Maxadilan also showed anti-apoptotic activity in hADSCs against serum withdrawal-induced apoptosis based on Annexin V/propidium iodide analysis and mitochondrial membrane potential assays. The anti-apoptotic effects of maxadilan correlated with the down-regulation of Cleaved Caspase 3 and Caspase 9 as well as up-regulation of Bcl-2. The chemical neural differentiation potential could be enhanced by maxadilan as indicated through quantitative PCR, Western blot and cell morphology analysis. Moreover, cytokine neural redifferentiation of hADSCs treated with maxadilan acquired stronger neuron-like functions with higher voltage-dependent tetrodotoxin-sensitive sodium currents, higher outward potassium currents and partial electrical impulses as determined using whole-cell patch clamp recordings. Maxadilan up-regulated the Wnt/β-catenin signalling pathway associated with dimer-dependent activity of PAC1R, promoting cell viability that was inhibited by XAV939, and it also activated the protein kinase A (PKA) signalling pathway associated with ligand-dependent activity of PAC1R, enhancing cell viability and neural differentiation potential that was inhibited by H-89. In summary, these results demonstrated that PAC1R is present in hADSCs, and maxadilan could enhance hADSC viability and neural differentiation potential in neural differentiation medium.

Topics: Adipocytes; Annexin A5; beta Catenin; Caspase 3; Caspase 9; Cell Differentiation; Cell Proliferation; Cell Survival; Cyclic AMP-Dependent Protein Kinases; Gene Expression Regulation; Heterocyclic Compounds, 3-Ring; Humans; Insect Proteins; Isoquinolines; Neurons; Patch-Clamp Techniques; Pituitary Adenylate Cyclase-Activating Polypeptide; Proto-Oncogene Proteins c-bcl-2; Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I; Signal Transduction; Stem Cells; Sulfonamides; Tetrodotoxin; Wnt Proteins

Pituitary adenylate cyclase-activating polypeptide (PACAP) increases neurite outgrowth, although signaling via its receptor PACAP-specific receptor (PAC1R) has not been fully characterized. Because mitochondria also play an important role in neurite outgrowth, we examined whether mitochondria contribute to PACAP-mediated neurite outgrowth. When mouse primary hippocampal neurons and Neuro2a cells were exposed to PACAP, neurite outgrowth and the mitochondrial membrane potential increased in both cell types. These results were reproduced using the PAC1R-specific agonist maxadilan and the adenylate cyclase activator forskolin, whereas the protein kinase A inhibitor H89 and mitochondrial uncoupling agent carbonyl cyanide m-chlorophenyl hydrazone (CCCP) inhibited these effects. Expression levels of peroxisome proliferator-activated receptor γ coactivator 1α (Pgc1α), a master regulator of mitochondrial activation, and its downstream effectors, such as cytochrome C and cytochrome C oxidase subunit 4, increased in response to PACAP. Knocking down Pgc1α expression using small interfering RNA or treatment with CCCP significantly attenuated neurite outgrowth and reduced the mitochondrial membrane potential in PACAP-treated cells. These data suggest that mitochondrial activation plays a key role in PACAP-induced neurite outgrowth via a signaling pathway that includes PAC1R, PKA, and Pgc1α.

Topics: Animals; Carbonyl Cyanide m-Chlorophenyl Hydrazone; Cell Line; Cells, Cultured; Colforsin; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Hippocampus; Insect Proteins; Isoquinolines; Membrane Potential, Mitochondrial; Mice; Mitochondria; Neurites; Neurons; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Pituitary Adenylate Cyclase-Activating Polypeptide; Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I; RNA Interference; RNA, Small Interfering; Second Messenger Systems; Sulfonamides; Trans-Activators; Transcription Factors