Phosphorylation of Transcription Factor CREB in Rat Spinal Cord after Formalin-Induced Hyperalgesia: Relationship toc-fosInduction

Abstract

The involvement of cAMP-responsive element-binding protein (CREB) signaling in tissue injury-induced inflammation and hyperalgesia has been characterized by measuring phosphorylation of CREB at serine-133 (CREB Ser133) using a specific antibody. In the unstimulated state, unphosphorylated CREB was observed in most nuclei of spinal neurons except for motor neurons, where only a small portion of neurons were stained. A few dorsal root ganglion (DRG) neurons were also CREBpositive. After a unilateral injection of formalin into the hindpaw, a strong and bilateral phosphorylation of CREB Ser133 was induced, as assessed by both immunohistochemistry and Western blot. PhosphoCREB (pCREB)-positive neurons were found in laminae I, II, V, and X of spinal cord on both sides. CREB phosphorylation was very rapid and reached peak levels within 10 min of formalin treatment, whereas few pCREBpositive neurons were seen in unstimulated spinal cord. The induction of pCREB was predominantly postsynaptic, because only 5% of DRG neurons were labeled after inflammation. In contrast to CREB phosphorylation, the induction of c-Fos expression reached peak levels 2 hr after formalin treatment and c-Fos induction was mainly ipsilateral. Both formalin-evoked CREB phosphorylation and c-Fos expression in the spinal cord were suppressed by pretreatment with the NMDA receptor antagonist MK-801 (3.5 mg/kg, i.p.) or halothane anesthesia.These results suggest that CREB signaling may play a role in the long-term facilitation of spinal cord neurons after hyperalgesia. Furthermore, our results indicate that CREB phosphorylation may be necessary but not sufficient for c-fos induction.

Reversal of NO-induced nociceptive hypersensitivity by St. John’s wort and hypericin: NF-κB, CREB and STAT1 as molecular targets

“…In the early stages of inflammation (Ji and Rupp 1997) and sciatic nerve injury (Ma and Quirion 2001), the phosphorylation of CREB is increased. Furthermore, this transcription factor regulates long-lasting effects of NO in neurons (Contestabile 2008).…”

Interactions with PDZ Proteins Are Required for L-Type Calcium Channels to Activate cAMP Response Element-Binding Protein-Dependent Gene Expression

“…The transcription factor cAMP response element-binding protein (CREB) plays an important role in each of these processes (Finkbeiner et al, 1997;Ji and Rupp, 1997;Carlezon et al, 1998;Milner et al, 1998;Silva et al, 1998;Anderson and Seybold, 2000). Within the hippocampus and other brain regions, CREB activation after brief stimulation (Յ3 min) is primarily mediated by calcium entry via L-type calcium channels (with a smaller component attributable to NMDA receptors) (Sheng et al, 1991;Deisseroth et al, 1996;Mermelstein et al, 2000).…”

Adenylate cyclase inhibition attenuates neuropathic pain but lacks pre-emptive effects in rats

“…Previous studies reported that the expression of phosphorylated CREB was involved in the temporal effects of hyperalgesia in inflammatory pain. 23 For instance, an increase in the expression of p-CREB occurred in the hindpaw of rats after subcutaneous injection of carrageenan, formalin, or complete Freund's adjuvant. 19,23,24 Those rats who suffered from neuropathic pain demonstrated a similar phenomenon.…”

“…23 For instance, an increase in the expression of p-CREB occurred in the hindpaw of rats after subcutaneous injection of carrageenan, formalin, or complete Freund's adjuvant. 19,23,24 Those rats who suffered from neuropathic pain demonstrated a similar phenomenon. 12,25 In contrast, Miletic et al reported that there were no differences in CREB content between control and study animals.…”