Regulatory role of CREB/BDNF signaling pathway in acute sleep deprivation-induced anxiety-like behavior mice

Objective:To investigate the regulatory role of cyclic adenosine monophosphate responsive element binding protein(CREB)/brain-derived neurotrophic factor(BDNF)signaling pathway in acute sleep deprivation(SD)-induced anxiety-like behavior mice(SD group)to study the mechanism of anxiety-like behavior better.Methods:The SD chamber was used to deprive the mice of sleep,and the anxiety-like behavior of the mice was verified using an open field test(OFT),elevated plus maze(EPM),forced swim test(FST),and tail suspension test(TST).Finally,proteins were detected by Western blotting.Result:OFT showed that the active distance and the time of stay in the central area were significantly reduced(P<0.05).EPM showed that the time and number of open arms in the SD group were significantly lower than in the control group(P<0.05).The FST showed that the forced swimming immobility time of the SD group was significantly lower than that of the control(P<0.05).Moreover,the TST showed that the immobility time of the tail suspension experiment in the SD group was significantly higher than that in the control group(P<0.05).Conclusion:Acute SD can regulate anxiety-like behavior in mice through the CREB/BDNF signaling pathway.

AB020.Inhibition of cyclic-AMP-response element binding protein and its impact on corneal wound healing in vitro and in vivo

Background:The cornea composes the outer surface of the eye and its transparency is required to allow light transmission to the retina.However,because of its position,the cornea is subjected to chemical and mechanical injuries that may lead to blindness.Our studies conducted using the human tissue-engineered cornea(hTEC)as a model provided evidence that the cyclic-AMP-response element binding protein(CREB)pathway is repressed during closure of corneal wounds.Based on these results,we hypothesized that closure of corneal wounds can be enhanced by preventing activation of CREB with the pharmacological inhibitor C646.Our goals were to proceed to the pharmacological inhibition of CREB(I)in vitro using the hTECs as a model,and then(II)in vivo using the rabbit as a model.Methods:The self-assembly approach was used to create hTECs,that were then wounded with an 8-mm diameter biopsy punch to create an epithelial defect.The tissues were then incubated with 10μM of C646(n=8).DMSO was used alone as a negative control(n=4).Closure of the wounds was monitored over a period of 5 days.Besides,the cornea of New Zealand white rabbits was debrided with an ethanol 70%solution to create an epithelial defect of 8-mm diameter.Several concentrations of C646(1,10,100μM et 1 mM)were applied as eye drops 3 times a day for up to 7 days.The wounded corneas(n=4 per concentration)were stained with fluorescein and photographed every day.Results:In vitro pharmacological inhibition of CREB with C646 considerably accelerated wound closure of all treated hTECs(4 days)compared to the control group(7 days).Moreover,the in vivo C646 treatment also accelerated wound healing of the corneas compared to the control group.The most effective concentration of C646 tested was the lowest(1μM),as it considerably enhanced the wound healing process.Conclusions:This study demonstrates that wound healing both in vitro and in vivo can be enhanced by preventing activation of CREB using a pharmacological inhibition approach.Most of all,this experiment suggests mediators from the CREB pathway as potential therapeutic targets on which we may influence to alter the wound healing dynamic of the cornea.We believe this study will lead to significant advancements in the clinical field of corneal defects.

Changes of CREB in rat hippocampus, prefrontal cortex and nucleus accumbens during three phases of morphine induced conditioned place preference in rats

Objective: To investigate the changes in CREB (cAMP response element binding protein) in hippocampus, PFC (prefrontal cortex) and NAc (nucleus accumbens) during three phases of morphine induced CPP (conditioned place preference) in rats, and to elucidate the role of CREB during the progress of conditioned place preference. Methods: Morphine induced CPP acquisition, extinction and drug primed reinstatement model was established, and CREB expression in each brain area was measured by Western Blot methods. Results: Eight alternating injections of morphine (10 mg/kg) induced CPP, and 8 d saline extinction training that extinguished CPP. CPP was reinstated following a priming injection of morphine (2.5 mg/kg). During the phases of CPP acquisition and reinstatement, the level of CREB expression was significantly changed in different brain areas. Conclusion: It was proved that CPP model can be used as an effective tool to investigate the mechanisms underlying drug-induced reinstatement of drug seeking after extinction, and that morphine induced CPP and drug primed reinstatement may involve acti-vation of the transcription factor CREB in several brain areas, suggesting that the CREB and its target gene regulation pathway may mediate the basic mechanism underlying opioid dependence and its drug seeking behavior.

Ohmefentanyl stereoisomers induce changes of CREB phosphorylation in hippocampus of mice in conditioned place preference paradigm

The present study was designed to determine the changes of phosphorylation of cAMP- response ele-ment binding protein (CREB) in hippocampus induced by ohmefentanyl stereoisomers (F9202 and F9204)in conditioned place preference (CPP) paradigm. The results showed that mice receiving F9202 and F9204displayed obvious CPP. They could all significantly stimulate CREB phosphorylation and maintained for along time without affecting total CREB protein levels. The effect of F9204 was similar to morphine whicheffect was more potent and longer than F9202. We also examined the effects of ketamine, a noncompetitiveN-mthyl-D-aspartate receptor (NR) antagonist, on morphine-, F9202- and F9204- induced CPP and phos-phorylation of CREB in hippocampus. Ketamine could suppress not only the place preference but also thephosphorylation of CREB produced by morphine, F9202 and F9204. These findings suggest that alterationsin the phosphorylation of CREB be relevant to opiates signaling and the development of opiates dependence.NR antagonists may interfere with opiates dependence and may have potential therapeutic implications.

Metabolic regulation by salt inducible kinases

In fasting mammals,the liver is the primary source of glucose production for maintenance of normoglycemia.In this setting,circulating peptide hormones and catecholamines cause hepatic glucose output by stimulating glycogen breakdown as well as de novo glucose production through gluconeogenesis.Fasting gluconeogenesis is regulated by a complex transcriptional cascade culminating in elevated expression of hepatic enzymes that promote gluconeogenesis and glucose export to the blood.The cAMP response element binding protein CREB and its co-activator CRTC2 play crucial roles in signal-dependent transcriptional regulation of gluconeogenesis.Recent work has identified a family of serine/threonine kinases,the salt inducible kinases(SIKs),which are subject to hormonal control and constrain gluconeogenic and lipogenic gene expression in liver.As normal regulation of gluconeogenesis and lipogenesis is disrupted in diabetic states,SIK kinases are poised to serve as therapeutic targets to modulate metabolic disturbances in diabetic patients.The purpose of this review is to 1)describe the identification of CRTCs CREB co-activators and their regulation by SIKs,2)discuss recent progress toward understanding regulation and function of SIKs in metabolism and 3)examine the potential clinical impact of therapeutics that target SIK kinase function.