Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P20366 (substance P)
 21,176 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The aim of the present study was to extend our previous hypothesis that the inflammatory reaction in psoriasis is neurogenic, and that substance P mediates the inflammation. For this purpose, the pattern of neurofilament-positive sensory nerve fibers was studied and the lengths and substance P content of these fibers measured morphometrically in dermal and epidermal compartments of the psoriatic lesion, psoriatic but lesion-free skin, and control skin. The epidermis and dermis of the psoriatic lesions were significantly more densely innervated with neurofilament-positive fibers than either lesion-free psoriatic or control skin. Although substance P is known to be rapidly degraded in tissues, and its actual concentrations in the sections were unknown, there was an increase in substance P containing nerves in the psoriatic lesion, the increase being significant in the epidermal nerve fibers. No significant differences in the measured parameters were obtained between lesion-free psoriatic and control skin. These results indicate that there is an altered pattern of sensory nerves in a psoriatic plaque and that substance P may be an important mediator in the inflammatory processes that contribute either to the initiation or maintenance of a psoriatic lesion.
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PMID:Quantification of cutaneous sensory nerves and their substance P content in psoriasis. 279 54

The immune system is important in the pathogenesis of psoriasis and emotional stress has precipitated psoriasis in many patients. Neuropeptides, alpha-Melanocyte stimulating hormone (alpha-MSH), beta-endorphin, met-enkephalin and substance P (SP) act as immunomodulators, and their secretion increases during periods of stress. To see whether these neuropeptides themselves might be related to psoriasis and/or to the aggressiveness of the disease, we evaluated the plasma neuropeptide levels in 13 patients with active psoriasis (patients with new lesions and/or pre-existing lesions that had become larger during the month before the study), in 11 patients with stable psoriasis and in 10 healthy controls. Plasma concentrations of neuropeptides were evaluated by RIA (immunoradiometric assay for beta-endorphin). Data were compared by the Student t-test for unpaired data. There were no significant differences between the plasma levels of any of the neuropeptides between active psoriatic patients and stable psoriatic patients, nor between the plasma levels of neuropeptides of psoriatic patients and those of control subjects. It seems unlikely that circulating neuropeptide levels are of primary importance in the manifestation of the psoriatic skin lesions.
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PMID:Plasma neuropeptide levels in psoriasis. 752 Nov 5

Neuropeptides released in skin from nerve fibers may interact with endogenous growth factors (or other mitogenic agents) to induce psoriasis lesions characterized by proliferating epidermal keratinocytes. The mitogenic effects of two neuropeptides, substance P (SP) and vasoactive intestinal peptide (VIP), on human adult and newborn keratinocytes were observed in the presence or absence of leukotriene B4 (LTB4) and leukotriene C4 (LTC4). In the presence of SP or VIP, LTB4 (but not LTC4) demonstrated substantial increase in thymidine incorporation into DNA, which was confirmed by cell-growth observations using the hexosaminidase assay. In the absence of either neuropeptide, LTB4 had only marginal effects, especially with adult (but not newborn) keratinocytes. With adult keratinocytes, LTB4 (but not LTC4) demonstrated synergy with both SP and VIP. VIP was mitogenic to keratinocytes at concentrations as low as 10(-12)M and exhibited a different dose-response curve depending on whether adult or newborn keratinocytes were used. The mitogenic effects of SP were abrogated by the SP antagonist spantide and those of VIP by the VIP antagonist [Ac-Tyr1, D-Phe2] growth-hormone-releasing factor (1-29) amide. This study suggests that the mitogenic effects of LTB4, which are elevated in psoriatic lesions, may be enhanced by the presence of neuropeptides, especially VIP. These effects can be reversed by antagonists that may have potential as drugs for the disease.
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PMID:Neuropeptides modulate leukotriene B4 mitogenicity toward cultured human keratinocytes. 767 35

The case of a 59-year-old female with a longstanding hemiplegia who developed unilateral psoriatic arthritis and unilateral psoriasis on the non-hemiplegic side only is reported. Investigations showed an erythrocyte sedimentation rate of 58 mm/h, with all classes of rheumatoid factor negative in serum and synovial fluid (SF). An inflammatory infiltrate was demonstrated in both knee joints despite the absence of clinical involvement on the hemiplegic side. In addition, while neurofilament and substance P (SP) immunoreactivity was demonstrated in both synovial specimens, conspicuously less SP was present in the clinically involved synovial membrane. Finally, SF levels of SP and IL1 beta were raised in the clinically involved knee only.
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PMID:Mechanism of joint sparing in a patient with unilateral psoriatic arthritis and a longstanding hemiplegia. 768 7

Both clinical and experimental evidence is accumulating on the role of the nervous system in the pathogenesis of psoriasis. Sporadic reports as well as extensive studies indicate that emotional stress can act as an exacerbating event in psoriasis. Moreover, that neurogenic mechanisms are operating in psoriasis is suggested by clinical, pharmacologic and experimental data. We have focused our investigations on the role of vasoactive intestinal peptide (VIP) and substance P (SP) in psoriatic lesions using a variety of experimental approaches: 1) receptor autoradiography; 2) immunohistochemistry; 3) radio-immunoassay; 4) human keratinocytes cultures. Our results indicate that an imbalance of VIP and SP exists in psoriatic lesions, and that these neuropeptides exert different and specific effects on human keratinocytes. At present, however, the finding of psoriasis being exacerbated by psychological factors cannot be satisfactorily explained merely by alterations of neuropeptides in the skin.
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PMID:Psoriasis and the nervous system. 807 40

Association of stress with psoriatic skin symptoms was studied in 13 patients with psoriasis by dividing the patients into low- and high-stress groups based on their clinical examination and answers to three questionnaires (General Health Questionnaire, a somatization scale, and a life change questionnaire). This study focused on skin mast cells and sensory nerves which are the principal components in neurogenic inflammation. Mast cells were stained enzyme-histochemically for tryptase and chymase, and neuropeptides substance P (SP), vasoactive intestinal peptide (VIP), and calcitonin gene-related peptide (CGRP) were demonstrated immunohistochemically. Compared to the low-stress group (n = 7), the patients in the high-stress group (n = 6) had more severe skin and joint symptoms. Furthermore, mast cells positive for chymase activity were prominently reduced, but tryptase-positive mast cells only slightly decreased in the lesional skin of the high-stress group. A similar tendency was also observed in the nonlesional skin. In the papillary dermis of the lesional skin, both VIP- and CGRP-immunoreactive nerves could be observed in the high-stress group whereas in the low-stress group these nerve fibers were hardly visible in the corresponding area. No association of SP with stress was observed. This study suggests that psychic stress is associated with exacerbation of psoriasis, and stress may induce alterations in the psoriatic lesions by increasing the neuropeptide content with a concomitant decrease in the activity of neuropeptide-degrading enzymes, especially mast cell chymase.
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PMID:Association of cutaneous mast cells and sensory nerves with psychic stress in psoriasis. 827 75

We investigated the function of peripheral blood mononuclear cells (PBMC) in 16 patients with active psoriasis, in 15 patients with static psoriasis and in 27 healthy volunteers, by examining in vitro proliferation and antigen- and mitogen-stimulated production of interleukin-2 (IL-2) and IL-4. Plasma levels of the neuropeptide substance P were also determined. Defective alloantigen (ALLO)- and phytohaemagglutinin (PHA)-stimulated IL-2 production was detected in 42% and in 45% of psoriatic patients, respectively. The number of defective IL-2 responders was higher in static (60%) than in active (25%) psoriasis. The reduction of IL-2 responses in the former group was associated with an increase of IL-4 production. Thus PBMC of 66% of patients with static psoriasis but none of the patients with active psoriasis produced elevated amounts of PHA-stimulated IL-4. Variations of plasma substance P levels followed the same pattern of IL-4, being higher in static than in active psoriasis. These observations suggest a co-ordinated action of IL-4 and substance P as modulators of the clinical course of psoriasis. Our data show a possible correlation between the clinical evolution of psoriasis and the production of type-1 and type-2 cytokines, suggesting that the former may have a prominent role in the activation of psoriasis, while the latter may play a protective role.
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PMID:Production of type-1 and type-2 cytokines by peripheral blood mononuclear cells of psoriatic patients. 855 80

Leukotriene A4 hydrolase is a bifunctional cytosolic enzyme, which both hydrolyses leukotriene A4 (LTA4) into leukotriene B4 (LTB4) and exerts aminopeptidase activity against opioid peptides. In the present study we have investigated whether the peptides angiotensin I and II, bradykinin, kallidine, histamine, dynorphin fragment 1-7 and substance P can act as substrates for epidermal and neutrophil LTA4 hydrolase. Among the tested substrates, dynorphin fragment 1-7 was found to be the best substrate for the enzyme. The aminopeptidase activity of epidermal and neutrophil LTA4 hydrolase against dynorphin fragment 1-7 was further characterized. The enzyme was purified from human epidermis and human neutrophils by anion exchange chromatography (Q-Sepharose) and affinity chromatography on a column with the LTA4 hydrolase inhibitor bestatin coupled to AH-Sepharose. The incubation of the dynorphin fragment 1-7 with LTA4 hydrolase resulted in the formation of tyrosine. The presence of the N-terminal amino acid tyrosine is essential for the interaction of opioids with their receptors, and this finding indicates that the LTA4 hydrolase can inactivate dynorphin fragment 1-7. After the two purification steps no other aminopeptidases acting at the N-terminal tyrosine of dynorphin fragment 1-7 was present in the preparation. This was demonstrated by the abolishment of the degradation at the N-terminal end of dynorphin fragment 1-7 when preincubating the enzyme preparation with LTA4 before the incubation with the dynorphin fragment 1-7. The abolishment of the aminopeptidase activity shows that activation of the hydrolase part of the enzyme, with conversion of LTA4 into the potent proinflammatory compound LTB4, results in an inhibition of the aminopeptidase activity of the enzyme. As a result, the catabolism of dynorphin fragment 1-7 and probably of other opioid peptides is inhibited, resulting in sustained biological effects of these opioids. This phenomenon may be important for the maintenance of inflammation in skin conditions, such as psoriasis and atopic dermatitis, in which LTB4 is formed.
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PMID:Characterization of the aminopeptidase activity of epidermal leukotriene A4 hydrolase against the opioid dynorphin fragment 1-7. 855 27

Nerve fibres immunoreactive to antibodies to vasoactive intestinal polypeptide (VIP) and substance P (SP) were increased in lesional psoriatic skin when assessed semiquantitatively. Biopsies from psoriatic plaques on the arm were studied in 13 patients and compared with biopsies from non-lesional areas (in three of the same psoriatic subjects) and from normal skin in seven non-psoriatic controls. Immunohistochemical methods were used on cryocut skin sections to demonstrate the neuropeptides SP, VIP, calcitonin gene-related peptide and neuropeptide Y, and the general neuronal marker protein gene product (PGP) 9.5. The immunofluorescence was examined by semiquantitative and, for PGP 9.5, by quantitative methods. VIP reactive nerve fibres were increased at areas of eccrine sweat glands throughout the dermis, at the dermo-epidermal junction, and in the epidermis, in psoriasis lesional skin. SP reactive nerve fibres were increased at the dermo-epidermal junction, where the nerves ran parallel with and perpendicularly through the junction. PGP 9.5 reactive nerve fibres showed an increase at the dermo-epidermal junction, in the papillary dermis, and at the eccrine sweat glands in lesional psoriatic skin but not in non-lesional, or in control skin. These findings support the hypothesis that neuropeptides may be involved in the pathogenesis of psoriasis.
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PMID:Neuropeptides and general neuronal marker in psoriasis--an immunohistochemical study. 859 14

Physical trauma is generally accepted as a possible factor in the pathogenesis of rheumatoid arthritis. In the last ten years, there have been a few rare case reports of physical trauma precipitating psoriasic arthritis. We observed two such cases following an occupational accident discovered one and a half year and two and a half year after onset of the first clinical manifestations. In the first case, a 43-year-old man had a fracture of the right calcaneus in March 1991. He was treated with nailing and also required emergency surgery of the posterior tibial artery. The tibiotarsal joint was normal radiologically. Pain persisted after treatment and in 1993 he presented with psoriasis of the scalp and several other localizations together with Hallopeau's acrodermatitis continua of the ankle, pathognomonic for psoriasic arthritis. Salazosufapyridin was given. The second case was a 50-year-old man who had major pain in both wrists immediately after falling on the palm of his hands in 1992. Bilateral carpal tunnel syndrome developed which did not respond well to surgery. In 1993, he developed inflammatory synovitis and also had psoriasis mainly located at the elbows. Immunological tests were negative. Cortisone and salazosulfapyridin were not particularly effective and the patient later developed arthritis of the hip and ankle joints. Physicians should be aware of physical trauma as a causative factor in psoriasic arthritis due to the potential legal implications. Criteria for imputability are: single major physical trauma, absence of clinical signs prior to the trauma, continuous clinical course, first signs occurring then predominating at the joint exposed to trauma. The pathophysiology of this type of arthritis is not well understood. Deep Koebner's phenomena could be involved. Activation of substance P has also been hypothesized.
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PMID:[Post-traumatic psoriatic arthritis. 2 cases]. 872 87


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