Effect of Repeated Electroacupuncture Intervention on Hippocampal ERK and p38MAPK Signaling in Neuropathic Pain Rats

Abstract

Results of our past studies showed that hippocampal muscarinic acetylcholine receptor (mAChR)-1 mRNA and differentially expressed proteins participating in MAPK signaling were involved in electroacupuncture (EA) induced cumulative analgesia in neuropathic pain rats, but the underlying intracellular mechanism remains unknown. The present study was designed to observe the effect of EA stimulation (EAS) on hippocampal extracellular signal-regulated kinases (ERK) and p38 MAPK signaling in rats with chronic constrictive injury (CCI) of the sciatic nerve, so as to reveal its related intracellular targets in pain relief. After CCI, the thermal pain thresholds of the affected hind were significantly decreased compared with the control group (P < 0.05). Following one and two weeks' EAS of ST 36-GB34, the pain thresholds were significantly upregulated (P < 0.05), and the effect of EA2W was remarkably superior to that of EA2D and EA1W (P < 0.05). Correspondingly, CCI-induced decreased expression levels of Ras, c-Raf, ERK1 and p-ERK1/2 proteins, and p38 MAPK mRNA and p-p38MAPK protein in the hippocampus tissues were reversed by EA2W (P < 0.05). The above mentioned results indicated that EA2W induced cumulative analgesic effect may be closely associated with its function in removing neuropathic pain induced suppression of intracellular ERK and p38MAPK signaling in the hippocampus.

Electroacupuncture Reduces the Effects of Acute Noxious Stimulation on the Electrical Activity of Pain-Related Neurons in the Hippocampus of Control and Neuropathic Pain Rats

“…“Zusanli” (ST36) and “Yanglingquan” (GB34) are the main points for treating sciatica and other types of leg pain according to the theory of traditional Chinese medicine. Our previous results also suggested that EA at “Zusanli” (ST36) and “Yanglingquan” (GB34) has cumulative analgesic effects for neuropathic pain [14–17]. The complete recording duration was about 30 min.…”

“…EA had an obvious analgesic effect and in CCI rats significantly diminished the injury-induced increase in synaptic cleft width and thinning of the postsynaptic density [15, 16]. It also activated the extracellular regulated protein kinases (ERK) signaling pathway in the hippocampus [17]. Previous studies suggested that ERK/mitogen-activated protein kinase (MEK) play an essential role in neuropathic pain [18].…”

<p>Brain Metabolism in Rats with Neuropathic Pain Induced by Brachial Plexus Avulsion Injury and Treated via Electroacupuncture</p>

“…Chronic pain is a multidimensional experience that continually affects the sensory, motor, emotional, cognitive, and other functions. [25][26][27] Neuropathic pain following BPAI is one of the most intractable types of chronic pain. [28][29][30][31] Studies have demonstrated that abnormal brain activity is an important aspect of its occurrence/persistence and might be associated with its severity.…”

The Long Noncoding RNA 150Rik Promotes Mesangial Cell Proliferation via miR-451/IGF1R/p38 MAPK Signaling in Diabetic Nephropathy

“…IGF1R is a protein and transmembrane tyrosine protein receptor which is involved in the IGF1/MAPK signalling pathway [48,49]. P38MAPK, an important member of the MAPK signalling pathway, can activate the MAPK signalling pathway [50][51][52][53], causing the proliferation of cells [54][55][56]. Moreover, our previous studies have shown that p38MAPK signalling is inhibited by miR-451 in early DN [15].…”