Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0030193 (pain)
 261,466 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

ATP causes the activation of p38 or ERK1/2, mitogen activated protein kinases (MAPKs) resulting in the release of tumor necrosis factor-alpha (TNF) and Interleukin-6 (IL-6) from microglia. We examined the effect of TNF and IL-6 on the protection from PC12 cell death by serum deprivation. When PC12 cells were incubated with serum-free medium for 32 hr, their viability decreased to 30 %. IL-6 alone slightly protected the death of PC12 cells, whereas TNF alone did not show any protective effect. In the meanwhile, when PC12 cells were pretreated with TNF for 6 hr and then incubated with IL-6 under the condition of serum-free, the viability of PC12 cells dramatically increased. TNF induced an increase of IL-6 receptor (IL-6R) expression in PC12 cells at 4-6 hr. These data suggested that 6 hr pretreatment with TNF increased IL-6R expression in PC12 cells, leading to an enhancement of IL-6-induced neuroprotective action.To elucidate the role of p38 in pathological pain, we investigated whether p38 is activated in the spinal cord of the neuropathic pain model. In the rats displaying a marked allodynia, the level of phospho-p38 was increased in the microglia of injury side in the dorsal horn. Intraspinal administration of p38 inhibitor suppressed the allodynia. These results demonstrate that neuropathic pain hypersensitivity depends upon the activation of p38 signaling pathway in microglia in the dorsal horn following peripheral nerve injury.
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PMID:Signaling of ATP receptors in glia-neuron interaction and pain. 1460 46

Inflammation of a peripheral nerve (neuritis) causes mechanical and thermal hyperalgesia in the region in which the inflamed nerve innervates. We investigated whether peripherally applied norepinephrine (NE) would exacerbate mechanical hyperalgesia in rats with neuritis. After inflammation of the left L5 spinal nerve with complete Freund's adjuvant, the foot withdrawal thresholds to mechanical stimuli applied to the affected hind paw (mechanical thresholds) were decreased significantly, indicating the development of mechanical hyperalgesia. An intradermal injection of NE to the affected paw further aggravated mechanical hyperalgesia transiently (1-3 days) and then recovered to the pre-NE injection levels afterwards. This responsiveness to NE (adrenergic sensitivity) was observed not only while rats were showing inflammatory hyperalgesia but also after recovering from it. The effect of NE on mechanical hyperalgesia was mediated by both peripheral alpha(1)- and alpha(2)-adrenoceptors. Immunohistochemical study of the previously inflamed nerve showed that proinflammatory cytokine tumor necrosis factor immunoreactivity was significantly higher in the rats showing adrenergic sensitivity compared to rats without adrenergic sensitivity. The data thus suggest that peripheral NE, when released in an excessive amount from the sympathetic nervous system, might play an important role in the aggravation of pain in neuritis.
J Pain 2003 May
PMID:Peripheral norepinephrine exacerbates neuritis-induced hyperalgesia. 1462 6

After injuries to the musculoskeletal system, peripheral nerve axons are exposed to numerous inflammatory mediators, including tumor necrosis factor-alpha (TNF). Exposure of sensory axons to TNF can cause behavioral hypersensitivity in the peripheral innervation territory of the affected axons. The hypothesis that TNF activates nociceptor axons was tested by using teased fiber techniques in the rat. Recordings were made of single nociceptors innervating both deep and cutaneous receptive fields supplied by the sciatic nerve. The axons proximal to the receptive field were exposed to ascending concentrations of TNF (0.01 to 1 ng/mL). In 21% of cutaneous and 9% of deep neurons, TNF rapidly evoked a transient response. There was no difference between deep and cutaneous nociceptors in the incidence of TNF responses. The majority of neurons responded to TNF injected into their receptive fields. Our data support that TNF can induce ectopic electrogenesis in a minority of nociceptor axons that innervate both deep and cutaneous tissues. This activity may correlate to the human perception of radiating pain that often accompanies neuritis.
J Pain 2002 Feb
PMID:Mid-axonal tumor necrosis factor-alpha induces ectopic activity in a subset of slowly conducting cutaneous and deep afferent neurons. 1462 53

After nerve injury, cyclooxygenase-2 (COX-2) is upregulated in spinal cord and peripheral nerve, the latter being dependent on tumor necrosis factor-alpha (TNF). Here we asked whether COX inhibitors attenuate pain behavior induced by chronic constrictive sciatic nerve injury (CCI) or intraneural injection of TNF (2.5 pg/ml). Rats received either 0.9% saline, the nonselective COX inhibitor ibuprofen (40 mg/kg) or the selective COX-2 inhibitor celecoxib (10 or 30 mg/kg) twice daily by gavage started 2 days before, 12 h or 7 days after surgery. Mechanical allodynia and thermal hyperalgesia induced by CCI was moderately, but consistently attenuated by early (day -2 or 12 h after CCI), but not late (7 days after CCI) ibuprofen and celecoxib treatment. Mechanical allodynia, but not thermal hyperalgesia induced by intraneural TNF, was reduced by ibuprofen, but not by celecoxib treatment 5 and 7 days after injection. Sciatic nerves, lumbar dorsal root ganglia (DRG) and spinal cords from rats with treatment started 12 h after surgery were analyzed for prostaglandin E2 (PGE2) levels 10 days after CCI. In injured nerves and ipsilateral DRG, PGE2 levels were increased. Ibuprofen treatment reversed PGE2 levels in injured nerves and DRG, whereas celecoxib blocked increased PGE2 levels only in nerves. In spinal cord, no change in PGE2 levels was observed. In contrast to the marked inhibition of nerve-injury-induced upregulation of PGE2 by COX inhibitors, the effect on pain behavior was modest. Nerve-injury- and TNF-induced pain-related behavior seem to be only partly dependent on peripheral prostaglandins.
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PMID:Cyclooxygenase inhibition in nerve-injury- and TNF-induced hyperalgesia in the rat. 1469 27

Phosphorylation of IkappaB through IkappaB kinase (IKK) is the first step in nuclear factor kappaB (NF-kappaB) activation and upregulation of NF-kappaB-responsive genes. Hence, inhibition of IKK activity may be expected to prevent injury-, infection-, or stress-induced upregulation of various proinflammatory genes and may thereby reduce hyperalgesia and inflammation. In the present study, we tested this hypothesis using a specific and potent IKK inhibitor (S1627). In an IKK assay, S1627 inhibited IKK activity with an IC50 value of 10.0 +/- 1.2 nm. In cell culture experiments, S1627 inhibited interleukin (IL)-1beta-stimulated nuclear translocation and DNA-binding of NF-kappaB. Plasma concentration time courses after intraperitoneal injection revealed a short half-life of 2.8 hr in rats. Repeated intraperitoneal injections were, therefore, chosen as the dosing regimen. S1627 reversed thermal and mechanical hyperalgesia at 3x 30 mg/kg in the zymosan-induced paw inflammation model and reduced the inflammatory paw edema at 3x 40 mg/kg. S1627 also significantly reduced tactile and cold allodynia in the chronic constriction injury model of neuropathic pain at 30 mg/kg once daily. The drug had no effect on acute inflammatory nociception in the formalin test and did not affect responses to heat and tactile stimuli in naive animals. As hypothesized, S1627 prevented the zymosan-induced nuclear translocation of NF-kappaB in the spinal cord and the upregulation of NF-kappaB-responsive genes including cyclooxygenase-2, tumor necrosis factor-alpha, and IL-1beta. Our data indicate that IKK may prove an interesting novel drug target in the treatment of pathological pain and inflammation.
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PMID:Specific Inhibition of IkappaB kinase reduces hyperalgesia in inflammatory and neuropathic pain models in rats. 1497 42

Salix extracts are in current use for the treatment of pain and inflammation. In order to obtain an insight into the mechanism(s) of action of the ethanolic Salix extract 1520L--which is essentially similar to an extract for which clinical studies have demonstrated analgesic effectiveness--its effects were evaluated in an established in vitro assay test system using primary human monocytes. The IC50-values obtained for the inhibition of lipopolysaccharide (LPS)-induced release of prostaglandin E2 (PGE2) reflecting cyclooxygenase (COX)-2-mediated PGE2 release were 47 microg/ml and 0.6 microg/ml, for the Salix extract 1520L and rofecoxib-like research compound L745337, respectively. There was no effect on COX-1 and COX-2 activity. The Salix extract inhibited the LPS-induced release of tumor necrosis factor-alpha, interleukin-1beta and interleukin-6 with IC50-values of 180.0, 33.0 and 86.0 microg/ml, respectively. Both, salicin and salicylate, had no effect in any of the parameters. Our results indicate that Salix extract 1520L inhibits COX-2-mediated PGE2 release through compounds other than salicin or salicylate. Our data further suggest that the proprietary Salix extract is a weak inhibitor of proinflammatory cytokines.
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PMID:Effects of an ethanolic salix extract on the release of selected inflammatory mediators in vitro. 1507 Jan 63

Numerous experimental studies provide evidence that proinflammatory cytokines induce or facilitate inflammatory as well as neuropathic pain and hyperalgesia. Direct receptor-mediated actions of cytokines on afferent nerve fibers have been reported as well as cytokine effects involving further mediators. The final outcome of cytokine action greatly depends on whether they act in the central of in the peripheral nervous system. Here we summarize recent findings on the peripheral mechanisms of action of three prototypic proinflammatory cytokines, interleukin-1beta, interleukin-6 and tumor necrosis factor-alpha, with regards to pain and hyperalgesia.
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PMID:Recent findings on how proinflammatory cytokines cause pain: peripheral mechanisms in inflammatory and neuropathic hyperalgesia. 1513 24

Etanercept is a dimeric fusion protein based on the p75 tumor necrosis factor (TNF) receptor. It binds to TNFalpha and blocks its biological activity. Subcutaneous etanercept is effective in the treatment of rheumatoid arthritis, psoriatic arthritis, and polyarticular-course juvenile rheumatoid arthritis. More recently, etanercept has shown efficacy in the treatment of adults with ankylosing spondylitis. In randomized, double-blind, placebo-controlled trials, subcutaneous etanercept 25mg twice weekly for 6-24 weeks significantly reduced disease activity in patients with active ankylosing spondylitis. In the largest trial, etanercept produced a response rate of 57% compared with 22% for placebo after 24 weeks (response was determined via the validated ASAS 20 response criteria developed by the Assessments in Ankylosing Spondylitis [ASAS] Working Group). Etanercept therapy significantly improved health-related quality of life in patients with ankylosing spondylitis compared with placebo. The greatest improvements in a 16-week study were seen in the domains of physical functioning, physical role, bodily pain, vitality, and social functioning. Etanercept was generally well tolerated, with few serious adverse events or treatment withdrawals. The most common adverse events were injection-site reactions and minor upper respiratory tract infections.
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PMID:Etanercept: in ankylosing spondylitis. 1516 37

Rheumatoid arthritis is a severe, debilitating condition for which existing therapies are of limited efficacy. In addition, the most common structure of treatment for patients with rheumatoid arthritis has recently been called into question, and many believe it should be reversed so that stronger treatments are administered earlier in the progression of the disease. Pivotal to the changes in rheumatoid arthritis treatment is the introduction of the pro-inflammatory tumor necrosis factor (TNF) antagonists. Overexpression of cytokines in inflamed joints plays an important role in joint inflammation and tissue damage, and the place of cytokines in the pathology of rheumatoid arthritis has offered hope that their antagonism will reduce symptoms and slow the advancement of the condition. With this in mind, etanercept, a fully human soluble TNF receptor fusion protein, was developed. The potency of this novel drug in blocking TNF activity has been shown in animal models and in clinical trials. The latter have demonstrated a positive safety profile and efficacy in reducing pain and the number of tender and swollen joints in rheumatoid arthritis patients. The effects of etanercept have also been observed soon after administration and have been sustained over several years. Etanercept has offered encouragement for those seeking new, more efficacious and less toxic methods of treating rheumatoid arthritis in children, adults and the elderly. In addition to the treatment of adult and juvenile rheumatoid arthritis, etanercept has also demonstrated utility in treating ankylosing spondylitis and psoriatic arthritis.
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PMID:The soluble tumor necrosis factor receptor etanercept: a new strategy for the treatment of autoimmune rheumatic disease. 1519 Mar 85

The postoperative period is associated with an increased production of cytokines, which augment pain sensitivity. We investigated the hypothesis that epidural clonidine premedication and postoperative patient-controlled epidural analgesia (PCEA) including clonidine would decrease the release of proinflammatory (interleukin (IL)-6, IL-1beta, IL-8, and tumor necrosis factor (TNF)-alpha) and antiinflammatory (IL-1 receptor antagonist (RA)) cytokines in patients who underwent elective colorectal surgery and that they would provide better postoperative analgesia. Forty patients were randomly assigned to 1 of 2 groups of 20 each: the control group received normal saline 10 mL, whereas the clonidine group received epidural clonidine 150 microg diluted with 9 mL of normal saline 30 min before surgery. Venous blood samples for cytokine levels were obtained before induction, at the end of surgery, and after surgery at 12 and 24 h. After surgery, the clonidine group patients received PCEA with morphine (0.1 mg/mL) and clonidine (1.5 microg/mL) in 0.2% ropivacaine 100 mL, whereas control group patients received only PCEA morphine and ropivacaine. Patients in the clonidine group exhibited longer PCEA trigger times, lower pain scores at rest and while coughing, less morphine consumption, and a faster return of bowel function throughout the 72-h postoperative observation period, compared with patients in the control group. For patients in the clonidine group, production of IL-1RA, IL-6, and IL-8 was significantly less increased at the end of the surgical procedure and at 12 and 24 h after surgery. However, the concentrations of IL-1beta and TNF-alpha were not significantly increased.
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PMID:The effect of epidural clonidine on perioperative cytokine response, postoperative pain, and bowel function in patients undergoing colorectal surgery. 1527 31


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