linoleic-acid and Psoriasis

Circulating fatty acids (FA) may be important in the psoriatic pro-inflammatory phenotype. FADS1 converts linoleic acid (LA) to arachidonic acid (AA), a precursor to potent signaling molecules. HMG-CoA reductase inhibitors (statins) increase FADS1/2 expression in vitro. Psoriasis patients (42 ± 14 years/age, 47% male) were randomized to 40 mg of atorvastatin (n = 20) or nothing (n = 10) for two weeks and plasma FA measured pre and post treatment. After treatment, LDL-C was 44% lower in the statin compared to the no-treatment group. Statins increased FADS1/2 expression, and lowered LA 12% (33% - > 29%, p<0.001) and raised AA 14% (7.7% - > 9.0%, p<0.01) with no change in the no-treatment group. In psoriasis, statins enhance AA and decrease LA, consistent with the action of enhanced FADS expression in vivo. Therapies intended to blunt the effects of AA on platelet aggregation, such as aspirin or omega-3 fatty acids, may require dose adjustment when co-administered with atorvastatin. NCT: NCT03228017.

Topics: Arachidonic Acid; Atorvastatin; Delta-5 Fatty Acid Desaturase; Fatty Acid Desaturases; Fatty Acids; Female; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Linoleic Acid; Male; Psoriasis

Psoriasis is a chronic, recurrent skin disease requiring long-term management. Agents that repair the skin's barrier function are invaluable additives in topical treatments of psoriasis. This multicenter, randomized, controlled trial evaluated the efficacy and safety of a linoleic acid-ceramide-containing moisturizer (LA-Cer) for mild-to-moderate psoriasis vulgaris. We randomized 178 patients from both northern and southern regions of China into two groups: 81 patients in the control group received mometasone furoate (MF, 0.1%) cream, while MF in combination with LA-Cer was administered to 86 patients in the treatment group for 4 weeks. The LA-Cer-MF group maintained the use of moisturizer after topical glucocorticoid administration. The primary endpoint, Psoriasis Area and Severity Index 50 (PASI 50) response, revealed the superiority of LA-Cer-MF with lower relapse rates at week 8. The use of the LA-Cer-containing moisturizer as maintenance therapy resulted in a continuous improvement in the clinical state in terms of body surface area, PASI, investigators' assessment of skin dryness and desquamation, and Physician Global Assessment of Psoriasis score, and in the patients' quality of life. Thus, the LA-Cer-containing moisturizer is a promising agent to prevent and treat psoriasis as it enhances the therapeutic effect induced by topical glucocorticoids and delays relapse.

Topics: Adult; Ceramides; China; Double-Blind Method; Female; Humans; Linoleic Acid; Male; Psoriasis; Quality of Life; Severity of Illness Index; Treatment Outcome

A complex assembly of lipids including fatty acids, cholesterol, and ceramides is vital to the integrity of the mammalian epidermal barrier. The formation of this barrier requires oxidation of the substrate fatty acid, linoleic acid (LA), which is initiated by the enzyme 12R-lipoxygenase (LOX). In the epidermis, unoxidized LA is primarily found in long-chain acylceramides termed esterified omega-hydroxy sphingosine (EOS)/phytosphingosine/hydroxysphingosine (collectively EOx). The precise structure and localization of LOX-oxidized EOx in the human epidermis is unknown, as is their regulation in diseases such as psoriasis, one of the most common inflammatory diseases affecting the skin. Here, using precursor LC/MS/MS, we characterized multiple intermediates of EOx, including 9-HODE, 9,10-epoxy-13-HOME, and 9,10,13-TriHOME, in healthy human epidermis likely to be formed via the epidermal LOX pathways. The top layers of the skin contained more LA, 9-HODE, and 9,10,13-TriHOME EOSs, whereas 9,10-epoxy-13-HOME EOS was more prevalent deeper in the stratum corneum. In psoriatic lesions, levels of native EOx and free HODEs and HOMEs were significantly elevated, whereas oxidized species were generally reduced. A transcriptional network analysis of human psoriatic lesions identified significantly elevated expression of the entire biosynthetic/metabolic pathway for oxygenated ceramides, suggesting a regulatory function for EOx lipids in reconstituting epidermal integrity. The role of these new lipids in progression or resolution of psoriasis is currently unknown. We also discovered the central coordinated role of the zinc finger protein transcription factor, ZIC1, in driving the phenotype of this disease. In summary, long-chain oxygenated ceramide metabolism is dysregulated at the lipidomic level in psoriasis, likely driven by the transcriptional differences also observed, and we identified ZIC1 as a potential regulatory target for future therapeutic interventions.

Topics: Ceramides; Humans; Linoleic Acid; Lipidomics; Molecular Structure; Psoriasis

Chronic pain and itch are common hypersensitivity syndromes that are affected by endogenous mediators. We applied a systems-based, translational approach to predict, discover, and characterize mediators of pain and itch that are regulated by diet and inflammation. Profiling of tissue-specific precursor abundance and biosynthetic gene expression predicted that inflamed skin would be abundant in four previously unknown 11-hydroxy-epoxy- or 11-keto-epoxy-octadecenoate linoleic acid derivatives and four previously identified 9- or 13-hydroxy-epoxy- or 9- or 13-keto-epoxy-octadecenoate linoleic acid derivatives. All of these mediators were confirmed to be abundant in rat and human skin by mass spectrometry. However, only the two 11-hydroxy-epoxy-octadecenoates sensitized rat dorsal root ganglion neurons to release more calcitonin gene-related peptide (CGRP), which is involved in pain transmission, in response to low pH (which mimics an inflammatory state) or capsaicin (which activates ion channels involved in nociception). The two 11-hydroxy-epoxy-octadecenoates share a 3-hydroxy-

Topics: Adult; Aged; Aged, 80 and over; Animals; Case-Control Studies; Female; Humans; In Vitro Techniques; Inflammation; Linoleic Acid; Male; Mice; Middle Aged; Nociceptors; Pain; Pruritus; Psoriasis; Rats; Rats, Sprague-Dawley; Receptors, Calcitonin Gene-Related Peptide; Sensory Receptor Cells; Skin; Systems Analysis

Fatty acid-binding proteins (FABPs) are postulated to serve as lipid shuttles that solubilize hydrophobic fatty acids and deliver them to appropriate intracellular sites. Epidermal FABP (E-FABP/FABP5) is predominantly expressed in keratinocytes and is overexpressed in the actively proliferating tissue characteristic of psoriasis and wound healing. In this study, we found decreased expression of the differentiation-specific proteins keratin 1, involucrin, and loricrin in E-FABP(-/-) keratinocytes relative to E-FABP(+/+) keratinocytes. We also determined that incorporation of linoleic acid was significantly reduced in E-FABP(-/-) keratinocytes. Although linoleic acid did not directly affect keratinocyte differentiation, keratin 1 expression was induced by the linoleic acid derivative 13(S)-hydroxyoctadecadienoic acid (13(S)-HODE), and this induction was concomitant with increased NF-κB activity. In E-FABP(-/-) keratinocytes, the expression of 13(S)-HODE and the subsequent induction of NF-κB activity was lower than in wild-type keratinocytes. The reduction of linoleic acid in E-FABP(-/-) keratinocytes led to decreased cellular 13(S)-HODE content, resulting in decreased keratin 1 expression through downregulation of NF-κB activity. The regulation of fatty acid metabolism by E-FABP during keratinocyte differentiation suggests that E-FABP may have a role in the pathogenesis of psoriasis.

Topics: Animals; Cell Differentiation; Cells, Cultured; Disease Models, Animal; Epidermis; Fatty Acid-Binding Proteins; Fatty Acids; Keratin-1; Keratinocytes; Linoleic Acid; Linoleic Acids; Membrane Proteins; Mice; Mice, Knockout; Neoplasm Proteins; NF-kappa B; Protein Precursors; Psoriasis; Signal Transduction

Psoriasis is uncommonly seen in Africans, probably partly due to genetic factors. However, the dietary habits of Africans may provide another explanation, which is explored in this paper. Maize, the staple diet in most parts of Africa, is high in linoleic acid but low in other polyunstaturated fatty acids and riboflavin. Linoleic acid is a precursor of prostaglandin E2 (PGE2) and its high intake, especially in the absence of other polyunsaturated fatty acids (PUFAs) and riboflavin, results in high tissue production of PGE2. PGE2 is known to suppress cellular immunity, resulting in decreased expression of psoriasis.

Topics: Black People; Diet; Humans; Linoleic Acid; Psoriasis; Zea mays

The principal in vivo oxygenase products of arachidonic acid and linoleic acid in psoriatic skin scales are 12-hydroxyeicosatetraenoic acid (R/S ratio = 5.7), 13-hydroxyoctadecadienoic acid (S/R = 1.9), and 9-hydroxyoctadecadienoic acid (R/S = 2.4). Definition of the enzymatic origin of these fatty acid derivatives is an important step in assessing their possible role in the pathogenesis of psoriasis. Psoriatic skin scales were incubated with radiolabeled arachidonic acid and linoleic acid and the monohydroxylated derivatives produced in vitro were characterized. The products of incubation with [3H]arachidonic acid were an enantiopure 15(S)-[3H]hydroxyeicosatetraenoic acid and a nonracemic mixture of the 12-[3H]hydroxyeicosatetraenoic acid steroisomers (R/S ratio = 4.5). An enantiopure 13(S)-[14C]hydroxyoctadecadienoic acid was produced from [14C]linoleic acid. No radiolabeled products were derived from incubations with heat-denatured scales. These results provide evidence for two distinct oxygenase activities that are preserved in psoriatic skin scales. One is that of an omega-6 oxygenase with strict (S) stereospecificity, consistent with the activity of a lipoxygenase. This enzyme activity appears to be similar to that of the 15-lipoxygenase which has been described in cultured human keratinocytes. The second activity is that of an arachidonic acid 12(R)-oxygenase that has not been observed in normal human epidermis but which appears to be expressed in psoriatic epidermis.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Arachidonic Acid; Arachidonic Acids; Chromatography, High Pressure Liquid; Humans; Hydroxyeicosatetraenoic Acids; Linoleic Acid; Linoleic Acids; Oxidation-Reduction; Oxygenases; Psoriasis; Skin; Stereoisomerism

Two different lipoxygenases have been identified in human and rat epidermis. One lipoxygenase has a (n-9)-specificity, converts arachidonic acid into 12-hydroxyeicosatetraenoic acid (12-HETE), and has been described by several investigators. Linoleic acid is not a substrate for this enzyme. The other lipoxygenase, with (n-6)-specificity, converts arachidonic acid into 15-HETE and linoleic acid into 13-hydroxyoctadecadienoic acid (13-HOD). Especially the latter lipoxygenase is thought to be involved in the regulation of the differentiation of the skin cells into a proper water-barrier layer. Linoleate is supposed to be the physiological substrate; this fatty acid is especially present in characteristic sphingolipids with unique structures.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Arachidonic Acid; Arachidonic Acids; Chromatography, High Pressure Liquid; Epidermis; Humans; Hydroxyeicosatetraenoic Acids; Linoleic Acid; Linoleic Acids; Linoleic Acids, Conjugated; Lipoxygenase; Psoriasis; Skin

Plasma phospholipids of patients with psoriasis have significantly reduced levels of dihomogammalinolenic acid (20:3n-6), arachidonic acid (20:4n-6) and adrenic acid (22:4n-6), the precursors of the 1, 2 and homo-2 series of prostaglandins (PGs). Concentrations of the 3 series PG precursor, eicosapentaenoic acid (20:5n-3) were normal. Hospital treatment with a coal tar regime produced a rise in 20:3n-6 to levels which were significantly above normal.

Topics: 8,11,14-Eicosatrienoic Acid; Adult; Coal Tar; Fatty Acids; Fatty Acids, Essential; Female; Humans; Linoleic Acid; Linoleic Acids; Male; Oleic Acid; Oleic Acids; Palmitic Acid; Palmitic Acids; Phospholipids; Prostaglandins; Psoriasis

Topics: Arachidonic Acid; Linoleic Acid; Psoriasis