Psychoneuroimmunology: the example of psoriasis.

The relationship between the central nervous system (CNS) and the endocrine system have been known for many years. Indeed some of the hormone secreting glands are actually located in the brain. The notion that the CNS and hormones are also involved in the bi-directional cross-talk with the Immune System has been the target of intense research in the recent decades. In this manner, for example, psychological states can be closely related to changes in immune mediators, and not only they may influence the evolution of human diseases, but may in the future lead to novel therapeutic interventions. This is the subject of this review, with particular emphasis on the role of psychoneuroimmunology (PNI) in psoriasis.

Generalized lupus panniculitis and antiphospholipid syndrome in a patient without complement deficiency.

Generalized chronic cutaneous lupus including lupus panniculitis in childhood is rare and usually occurs in the setting of genetic complement deficiencies. The association with antiphospholipid syndrome is even more rare. We report a 13-year-old girl with extensive lupus panniculitis since the age of 8 months and no evidence of complement deficiency. She recently developed antiphospholipid syndrome characterized by anticardiolipin antibodies and digital necrosis.

A pilot study of hypnosis in the treatment of patients with psoriasis.

BACKGROUND: The use of psychological therapies for patients with psoriasis has been proposed based on observations that the severity of their disease may correlate with emotional stress. The aim of this pilot study was to evaluate the effect of hypnosis as a treatment modality for patients with psoriasis. METHODS: We performed a 3-month randomized, single-blind, controlled trial of the use of hypnosis in adults with stable, chronic, plaque-type psoriasis. Highly or moderately hypnotizable subjects were randomized to receive either hypnosis with active suggestions of improvement (5 patients) or neutral hypnosis with no mention of their disease process (6 patients). After this period, the study was unblinded, and all the patients were treated for an additional 3 months with hypnosis with active suggestions of improvement. RESULTS: Highly hypnotizable subjects showed significantly greater improvement than did moderately hypnotizable subjects, independent of treatment group assignment (active suggestion or neutral hypnosis). CONCLUSION: Although this study included a very limited number of patients, the results suggest that hypnosis may be a useful therapeutic modality for highly hypnotizable subjects with psoriasis, and merits further testing in a larger patient population.

"Centripetal flagellate erythema": a cutaneous manifestation associated with dermatomyositis.

We describe 3 patients with dermatomyositis who presented with flagellate erythema. This cutaneous eruption is characterized by erythematous linear lesions on the trunk and proximal extremities. Histologic examination of this eruption in one of our cases revealed an interface dermatitis. Review of the literature and records of 183 patients with connective tissue diseases from our institution has shown that this peculiar eruption has been reported only in dermatomyositis. Because of the location of this eruption, we encourage the use of the term "centripetal flagellate erythema" to distinguish this entity from other linear eruptions seen in patients with connective tissue diseases.

Alternative medicine. Is it all in your mind?

Therapeutic interventions may trigger nonspecific mechanisms whose effects are not attributable to the specific properties of a given treatment. Recent investigations on the placebo effect as well as other mind-body interactions are helping us to understand some of the underlying mechanisms, as well as beginning to provide us with potentially effective adjuvant treatment strategies for a variety of human diseases.

Exogenous but not endogenous substance P releases histamine from isolated human skin fragments.

Neuropeptides such as substance P are released from nerve terminals following the stimulation of sensory fibers, and are thought to participate in neurogenic inflammation in the skin; it is often speculated that mast cell activation is an intermediate step in this process. In the present study we addressed this hypothesis using freshly obtained skin explants derived from human neonatal foreskins or adult skin resections. The results demonstrate that when substance P is released from human skin by incubation in the presence of capsaicin (10(-5)M), no histamine is released from human isolated skin fragments. In each experiment human recombinant stem cell factor and/or exogenously applied substance P effectively evoked histamine release from the explants, attesting to the viability of the mast cells in the preparation. The concentrations of exogenously applied substance P required to elicit histamine release, however, were large (> 10 microM). These results indicate that substance P released from cutaneous sensory nerve fibers does not reach sufficient concentrations in the skin to degranulate mast cells. These data support the hypothesis that the vascular effects of neurogenic inflammation occur independently of mast cell activation.

Rapid increases in peptide processing enzyme expression in hippocampal neurons.

Recent studies have demonstrated that seizure activity causes a dramatic increase in neuropeptide expression in specific regions of the rat hippocampus. In this study we investigated the effect of electroconvulsive treatment (ECT) on the expression of three posttranslational processing enzymes involved in the production of many bioactive peptides from their inactive precursors. Peptidylglycine alpha-amidating monooxygenase (PAM) converts peptidylglycine substrates into alpha-amidated products and prohormone convertases 1 and 2 perform the tissue-specific endoproteolytic cleavage of many prohormones. After a single ECT, in situ hybridization demonstrated a rapid increase in the level of PAM mRNA in the dentate granule cells of the hippocampus, reaching peak levels between 1 and 4 h and then returning to near baseline levels within 24 h. Northern blot analysis confirmed the changes in PAM mRNA expression seen by using in situ hybridization. Similar rapid changes in PAM mRNA expression were seen after repeated ECT, suggesting that chronic ECT did not affect the regulation of PAM expression in the hippocampus. Immunohistochemical staining demonstrated an increase in PAM protein in the molecular layer of the dentate gyrus at 4 and 8 h after a single ECT. Based on in situ hybridization, levels of mRNA for the prohormone convertases 1 and 2 were also increased in dentate granule cells after a single ECT. Prohormone convertase 2 mRNA levels exhibited a slower response to ECT, not reaching maximal levels until 8 h after ECT. The response of the dentate granule cells of the hippocampus to ECT provides a model system for studying the rapid, coordinate regulation of peptide-processing enzymes.

Use of endoproteases to identify catalytic domains, linker regions, and functional interactions in soluble peptidylglycine alpha-amidating monooxygenase.

The production of alpha-amidated peptides is accomplished through the sequential action of two enzymes, peptidylglycine alpha-hydroxylating monooxygenase (PHM) and peptidyl-alpha-hydroxyglycine alpha-amidating lyase (PAL), that are contained within the bifunctional peptidylglycine alpha-amidating monooxygenase (PAM) protein. Tissue-specific alternative splicing and endoproteolysis are known to generate both soluble and integral membrane mono- and bifunctional PAM proteins. In order to investigate the functional consequences of these differences we purified PAM-3, a soluble 95-kDa bifunctional form of the enzyme, from the spent medium of stably transfected hEK-293 cells. Using NH2-terminal sequence analysis of products of limited endoproteolysis and antibody cross-reactivity we identified protease-sensitive regions at the NH2 terminus, between the 35-kDa PHM and 42-kDa PAL domains and at the COOH terminus of the protein. Endoproteolytic removal of the COOH-terminal region from the bifunctional PAM-3 protein shifted the pH optimum of PHM to a more alkaline pH, increased the turnover number (kappa(cat)) of PHM and decreased its KM for alpha-N-acetyl-Tyr-Val-Gly; the catalytic properties of PAL were not altered. Since peptide amidation can be a rate-limiting step in the biosynthesis of neuropeptides, similar increases in PHM activity in vivo may play an important role in regulating the extent of peptide alpha-amidation.

Expression of a peptide processing enzyme in cultured cells: truncation mutants reveal a routing domain.

Peptidylglycine alpha-amidating monooxygenase (PAM) is a bifunctional enzyme responsible for the alpha-amidation of peptides in secretory granules of neuroendocrine cells. The single gene encoding PAM undergoes tissue-specific alternative splicing and endoproteolytic processing to generate bifunctional membrane proteins with a single transmembrane domain as well as soluble proteins that are mono- or bifunctional. In order to examine the endoproteolytic processing and subcellular localization of the various forms of PAM in cells lacking regulated secretory granules, we established stably transfected hEK-293 cell lines expressing naturally occurring and mutant forms of PAM. As expected, newly synthesized soluble PAM proteins were rapidly secreted into the medium. Integral membrane protein forms of PAM were largely localized in the perinuclear region with punctate staining visible throughout the cell and 2-5% of the enzyme activity detectable on the cell surface. Bifunctional PAM proteins were slowly released into the medium after expression of integral membrane protein forms of PAM. Deletion of 77 amino acids from the COOH-terminus of the integral membrane forms of PAM resulted in a membrane-bound protein which retained both enzymatic activities but accumulated on the cell surface. Rapid internalization of full-length PAM proteins was observed by incubating live cells with antiserum to PAM; deletion of the COOH-terminal domain eliminated the ability of cells to internalize PAM. Thus the cytoplasmic domain of integral membrane PAM contains a routing determinant recognized by cells lacking the regulated secretory pathway.

Substrate properties of C1 inhibitor Ma (alanine 434----glutamic acid). Genetic and structural evidence suggesting that the P12-region contains critical determinants of serine protease inhibitor/substrate status.

The serine protease inhibitor (serpin) C1 inhibitor inactivates enzymes involved in the regulation of vascular permeability. A patient from the Ma family with the genetic disorder hereditary angioedema inherited a dysfunctional C1 inhibitor allele. Relative to normal plasma, the patients's plasma contained an additional C1 inhibitor immunoreactive band, which comigrated with normal C1 inhibitor cleaved by plasma kallikrein, C1s, or factor XIIa. C1 inhibitor Ma did not react with a monoclonal antibody to a neoepitope that is present in complexed and cleaved normal C1 inhibitor, suggesting conformational differences between cleaved normal C1- inhibitor and cleaved C1 inhibitor Ma. Molecular cloning and sequencing of exon 8 of the C1 inhibitor Ma allele revealed a single C to A mutation, changing alanine 434 to glutamic acid. Ala 434 of C1 inhibitor aligns with the P12 residue of the prototypical serpin alpha 1-antitrypsin. The P12 amino acid of all inhibitory serpins is alanine, and it is present in a highly conserved region on the amino-terminal side of the serpin-reactive center loop. Whereas normal C1 inhibitor expressed by transfected COS-1 cells formed complexes with and was cleaved by kallikrein, fXIIa, and C1s, COS-1-expressed Ala434---Glu C1 inhibitor was cleaved by these enzymes but did not form complexes with them. These results, together with evidence from other studies, suggest that serpin protease inhibitor activity is the result of protein conformational change that occurs when the P12 region of a serpin moves from a surface location, on the reactive site loop of the native molecule, to an internal location within sheet A of the complexed inhibitor.

The human C3b receptor: function and role in human diseases.

The human C3b receptor (CR1) is a polymorphic glycoprotein which functions regulating the complement system by inhibiting the activation of C3 and C5, through its effect on their convertases, and serving as cofactor for factor I in mediating the degradation of C3b to its inactive fragment C3bi and further to C3d-g. The latter are then ligands for their respective receptors on leukocytes, CR3 and CR2. Additionally, CR1 on erythrocytes endows these cells with the capacity to deliver immune complexes (IC) to the reticuloendothelial system, resulting in their clearance from the circulation. On phagocytes, this receptor participates in the process of endocytosis of foreign particles. There is a wide inherited variation of CR1 expression on erythrocytes (CR1/E) of different individuals. Patients with diseases which feature elevated levels of IC, such as systemic lupus erythematosus, leprosy, and AIDS, have a marked decrease of CR1/E, which may result in an altered clearance. This reduction appears to be related to disease activity, and the most probable site for CR1/E loss is during the transfer of IC to macrophages. Healthy neutrophils increase tenfold their expression of CR1 in response to the effect of chemoattractant peptides. Neutrophils from patients with AIDS display an altered response to stimulation. This defect may be of relevance in the process of endocytosis.

The expression of C3b receptors in the differentiation of discoid lupus erythematosus and systemic lupus erythematosus.

We studied the expression of the C3b receptor, CR1, on erythrocytes (E-CR1) of patients who, in spite of having mild systemic symptoms, were diagnosed as having discoid lupus erythematosus and followed accordingly. We found that E-CR1 was markedly reduced in these patients, similar to that seen in patients with systemic disease. In contrast, those patients with completely asymptomatic discoid lupus erythematosus had the same expression of E-CR1 as the normal population.