Diese Arbeit verdeutlicht die Wirkung von Chondroitinsulfat auf die Synthese von Prostaglandin E2 in humanen mesenchymalen Stromazellen in Abhängigkeit ihres Sulfatierungsgrades. MSC zeichnen sich durch ihre antiinflammatorischen Eigenschaften aus und haben damit einen modulierenden Effekt auf Wundheilungsprozesse. Als Vorläuferzellen von Osteoblasten sind sie direkt an der Knochenneubildung beteiligt. Eine persistierende Entzündung hat eine kontinuierliche Freisetzung von Zytokinen, wie IL-1 zur Folge. Es konnte gezeigt werden, dass IL-1 in hMSC zu einer Freisetzung von PGE2 führt. Unter kurzzeitiger Wirkung stimuliert PGE2 die Knochenneubildung. Eine langanhaltende Präsenz leitet dagegen die Bildung des Faktors RANKL, einen die Osteoklastogenese stimulierenden Faktor, ein. Seit langem ist der positive Effekt von Chondroitinsulfat in chronischen Entzündungsprozessen, wie Rheumatoider Arthritis, bekannt. Zudem werden sie in aktuellen Studien als Beschichtungsbestandteile von Knochenimplantaten verwendet. Sie führten hier zu einer besseren Bioinduktivität und Biokonduktivität. Bisher ist dennoch der molekulare Wirkmechanismus nicht genau beschrieben. Die Schwierigkeit besteht darin, dass die molekularen Signalkaskaden für die einzelnen Kulturmoldelle Unterschiede aufweisen und kein ubiquitärer Mechanismus dargestellt wird. In hMSC führte die Stimulation mit IL-1 unter vorheriger Zugabe von Chondroitinsulfat zu einer Reduktion der PGE2 Freisetzung. Der Effekt des hochsulfatierten sCS3 war gegenüber dem nativen C4S verstärkt. Die reduzierende Wirkung von C4S setzte verzögert ein. Es ist bereits bekannt, dass die negative Ladung der CS zu einer Bindung von Zytokinen führt. Dadurch wird eventuell die Konzentration der Zytokine, wie IL-1 im Bereich der Zellrezeptoren erniedrigt und führt zu einer verringerten Stimulation der Zelle. Denkbar ist auch die Beeinflussung der intrazellulären Signaltransduktionskaskade durch die Bindung der CS an einen speziellen, bisher unbekannten, Membranrezeptor. Die entscheidenden Enzyme der PGE2 Synthese sind die Cyclooxygenase-2 (Cox-2) und die mikrosomale Prostaglandin E Synthase 1 (mPGES1). Die mRNA beider Enzyme war unabhängig vom Sulfatierungsgrad der CS reduziert. Dieser Effekt konnte auf Protein-ebene nicht belegt werden. Die produzierte Proteinmenge an mPGES1 wird durch IL-1 induziert, bleibt aber auch durch Zugabe von CS unverändert. Somit kann von einer erhöhten Translationseffizient und mRNA Stabilität der mPGES1 RNA ausgegangen werden. MAPK Kinasen sind entscheidende Schnittstellen bei der Regulation der mRNA Stabilität als auch der Aktivität von Transkriptionsfaktoren. In dieser Studie konnte die MAPK p38 als entscheidendes Enzym bei der Wirkung von CS auf die PGE2 Synthese ermittelt werden. Dabei führten sowohl das natürliche C4S als auch das hochsulfatierte sCS3 zu einer verringerten Aktivierung. Der Transkriptionsfaktor NfkB ist einer von mehreren, die an den Promotorbereichen der beiden induzierbaren PGE2 Enzyme, Cox-2 und mPGES1, binden. Es ist anzunehmen, dass die hier aufgezeigte verringerte Aktivität von NfkB als auch die verhinderte Translokation in den Zellkern eine reduzierte Transkription der jeweiligen mRNA bedingten. Abhängig vom untersuchten Modell und den verwendeten Kulturbedingungen können diese Prozesse moduliert sein. Die Erkenntnisse dieser experimentellen Arbeit liefern einen weiteren wichtigen Baustein zum Verständnis der molekularbiologischen Abläufe während entzündlicher Prozesse. Die Verwendung von Chondroitinsulfat, insbesondere hochsulfatiertes CS, in Kombination mit hMSC kann gezielt zu einer Verringerung der Entzündungsreaktion während der Implantateinheilung führen. Die durch PGE2 hervorgerufenen Symptome, wie erhöhte Gefäßpermeabilität, Schwellung und verstärktes Schmerzempfinden begründen diese positiven Effekte.

京都大学 / 0048 / 新制・論文博士 / 博士(医学) / 乙第13138号 / 論医博第2138号 / 新制||医||1025(附属図書館) / (主査)教授 伊達 洋至, 教授 坂井 義治, 教授 武藤 学 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM

Erythema is a hallmark skin response to excessive ultraviolet radiation (UVR) and is associated with cutaneous inflammation. Both are mediated by inflammatory mediators including nitric oxide (NO), prostaglandin E2 (PGE2) and chemoattractants such as 12-hydroxyeicosatetraenoic acid (12-HETE) leading to vasodilation and increased leukocyte infiltration. The erythematous response is more pronounced in individuals with low basal melanin levels or who fail to respond to UVR with a robust up-regulation of melanogenesis. While melanin production is a key function of melanocytes, these cells can also produce NO and PGE2, and are located in close proximity to the dermal vasculature. It has been hypothesized that melanocytes with poor melanogenic capacity may participate in the inflammatory response to UVR. The aim of this project was to investigate the inflammatory response in the skin of individuals with either skin phototype (SPT) 1 or 4 to UVR. Sixteen normal healthy individuals were selected for study (8 SPT-1 & 8 SPT-4). Buttock skin was investigated by immunohistochemistry for leukocyte subtypes, eicosanoid producing enzymes and NO synthases under basal and UVR-stimulated conditions. In addition primary cultures of epidermal melanocytes (EM) were established from 16 individuals (8 SPT-1 & 8 SPT-4) and assessed for the presence of eicosanoid-producing enzymes, melanogenic enzymes and NO synthases, by immunocytochemistry, Polymerase Chain Reaction and Western Blotting and for the production of the main pro-inflammatory eicosanoid PGE2 by ELISA and Mass Spectrometry. Moreover, the fatty acid composition of cultured melanocytes was assessed by Gas Chromatography. Results showed that individuals with SPT-1 had significantly greater neutrophil infiltration into the epidermis than those with SPT-4 at 24 hrs post-UVR. Moreover, CD3+ lymphocyte infiltration into the dermis was significantly greater in individuals with SPT-4 than those with SPT-1 at 24 and 72 hrs post-UVR. NOS-1, NOS-3, 12-LOX and COX-2 expression were significantly increased in SPT-1 skin, while NOS-2 and 15-LOX were significantly increased in SPT-4 skin. As 12-LOX and COX-2 products are chemoattractive (for neutrophils) and pro-inflammatory respectively these data could explain the greater observed neutrophil infiltration in SPT-1. The 15-LOX product (15-HETE) is anti-inflammatory and may suggest that 15-LOX up-regulation in SPT-4 skin may aid resolution of the sunburn response, which in part may be mediated by CD3+ lymphocytes and a class-switch in eicosanoid production from COX to LOX products. Melanocyte primary cultures surprisingly showed that SPT was not correlated with melanin content or melanogenic enzyme expression/activity suggesting that all melanocytes in vitro contained the necessary cellular machinery to produce melanin. This finding may reflect also their equal treatment under these enriched culture conditions, which may or may not be available to these cells in situ. Moreover, all melanocytes expressed the necessary machinery (PLA2, COX-1, cPGES) to produce PGE2. However, only some cultures did so at baseline and in response to UVR, and this was not correlated with SPT. A positive correlation was found however between expression level of dopachrome tautomerase (DCT) and protection against PGE2 production in response to UVR, which may suggest a novel role for DCT unrelated to melanogenesis. In summary this research project has generated data that highlights differences between the skin of individuals with SPT-1 and those with SPT-4, and may provide evidence that the keratinocyte partner contributes significantly to the SPT-associated response. This research may also suggest DCT as a novel therapeutic target to protect EM from participation in the UVR-associated inflammatory response in skin. / Wellcome Trust

<p>  </p> <p>A historically important reaction, the Ueno-Stork reaction promotes, through the use of toxic organotin species, the cyclization of a haloacetal onto an alkene generating bicyclic acetals. This reaction has been used over the years in several total syntheses of biologically relevant natural products, especially the prostaglandin class of natural products. Herein, will be described the development of a novel nickel-catalyzed Ueno-Stork cyclization reaction, which no toxic organotin and radical promoters are used, and instead a greener, operationally friendly, and non-toxic earth abundant nickel catalyst is applied. Optimization studies, substrate scope, scalability, relative stereochemistry of the bicyclic acetals, as well as derivatization of the products were studied. Furthermore, the newly developed reaction was applied on the total synthesis of tricyclic-PGDM Methyl ester, a prostaglandin D2 metabolite of important clinical relevance that currently suffers from material supply issues.</p> <p>Cyclopropanol ring opening reactions have different reactivity modes. Either a metal homoenolate species or a b-keto radical species can be formed after ring opening depending on the reaction conditions applied. More specifically, hydroxycyclopropanols have been studied to access several important motifs present in an array of natural products and medicinally important molecules. The Dai group has used this strategy to access several motifs through intramolecular trapping of the homoenolate species with and without the presence of carbon monoxide to generate oxaspirolactones, THF/THP-fused bicyclic lactones, and disubstituted THF/THP heterocycles. Herein, it will be discussed the application of similar concepts to access new classes of heterocycles 4-ketovalerolactones and 3-furanones. The optimization of two reaction conditions to selectively synthesize each product starting from the same starting material was studied. Furthermore, the substrate scope, scale-up, and derivatization studies of each motif will be disclosed. </p>

No description available.

No / Human saphenous vein endothelial cells (HSVECs) derived from primary cultures of adult human veins constitute an excellent in vitro model for studying human endothelial metabolism. In this study we report the14C-labelled prostanoid profile of HSVECs under resting and stimulated conditions and the effect of the n-3 polyunsaturated fatty acids eicosapentaenoic acid and docosahexaenoic acid on them. Results indicate that HSVECs while under resting conditions produce mainly prostaglandin F2 ¿(PGF2 ¿). After stimulation with calcium ionophore A23187, the cells were found to synthesise PGI2, PGE2and PGF2¿as major products and thromboxane B2and PGD2as minor products. Production of14C-labelled hydroxyeicosatetraenoic acids was not detected. Eicosapentaenoic acid was found to inhibit basal and stimulated prostanoid production whereas docosahexaenoic acid inhibited basal but strongly increased stimulated prostanoid production. These results may offer the basis for further studies aiming to investigate targets for pharmacological intervention in inflammatory conditions.

Iberische und Eurasische Luchse zeigen einen saisonalen Monoöstrus. Nach der Ovulation findet man frisch gebildete (freshCL) und physiologisch persistierende Gelbkörper (corpora lutea, perCL). Funktionelle perCL verhindern eine Ovulation außerhalb der Zuchtsaison durch konstant erhöhte Progesteron-(P4)-Plasmawerte. Hauskatzen zeigen einen saisonalen Polyöstrus. Nach der Ovulation werden CL gebildet, deren Lebensspanne in Abhängigkeit von einer Trächtigkeit durch unterschiedliche P4-Plasmaprofile charakterisiert ist. Ziel der Dissertation war es, die Synthese und Rezeption von Steroiden und Prostaglandinen (PG) in CL von Feliden zu untersuchen, um potentiell luteotrophe und luteolytische Faktoren zu identifizieren. Während der Gelbkörperphase trächtiger und nicht-trächtiger Katzen weisen CL gleicher Histomorphologie, unabhängig vom Vorhandensein einer Trächtigkeit, ähnliche steroidogene Kapazitäten auf. Die Abnahme der CL-Funktion spiegelt sich im graduellen Verlust der Steroidbiogenese wider. Bei Luchsen ist die steroidogene Kapazität der perCL im Proöstrus herabgesetzt, aber im Metöstrus wieder verstärkt. Die steroidogene Kapazität ist demnach mit verschiedenen CL-Stadien und dem Reproduktionszyklus assoziiert. Die Synthese und Rezeption von PGE2 erfolgen bei Katze und Luchs unabhängig vom CL-Stadium und dem Reproduktionszyklus. Hohe Werte an luteotrophem PGE2 in perCL könnten für die funktionelle und strukturelle CL-Persistenz beim Luchs verantwortlich sein. Der feline CL ist zur Bindung von luteolytischem PGF2alpha fähig, jedoch ist die Kapazität zur Synthese begrenzt. Feliden weisen keine PGF2alpha-assoziierte luteale Regression in Abwesenheit einer Trächtigkeit auf. Allerdings wurden Höchstwerte an PGF2alpha in der Plazenta, wie auch im Plasma (PGFM), im letzten Trächtigkeitstrimester der Katze gemessen. Folglich ist die feline Plazenta zur Synthese von luteolytischem PGF2alpha fähig, welches die CL-Regression und Geburt am Ende der Trächtigkeit ermöglicht. / Iberian and Eurasian lynxes exhibit a seasonal monooestrus. After ovulation, freshly formed (freshCL) coexist with physiologically persistent luteal bodies (corpora lutea, perCL). Functional perCL prevent ovulation outside the breeding season through constantly elevated plasma progesterone (P4) levels. Domestic cats show a seasonal polyoestrus. After ovulation, CL are built with lifespans being characterised by different plasma P4 profiles dependent on pregnancy. The aim of the dissertation was to characterise the synthesis and reception of steroids and prostaglandins (PGs) in CL of felids to identify potential luteotrophic and luteolytic factors. During the luteal lifespan of pregnant and non-pregnant cats, CL of equal histomorphology exhibit similar steroidogenic capacities, irrespectively of an ongoing pregnancy. The functional demise of CL mirrors the gradual loss of steroid biogenesis. In lynxes, the steroidogenic capacity of perCL is limited at prooestrus, but is enhanced again during metoestrus. The steroidogenic capacity is thus associated with different CL stages and the reproductive cycle. The synthesis and reception of PGE2 in cat and lynx is independent on the CL stage and reproductive cycle. High levels of luteotrophic PGE2 in perCL might be responsible for the functional and structural CL persistence in lynxes. The feline CL is capable of binding luteolytic PGF2alpha; however, the capacity to synthesise PGF2alpha is limited. Felids show no PGF2alpha-associated luteal regression in the absence of pregnancy. Interestingly, peak levels of PGF2alpha in the placenta, as well as in plasma (PGFM), were measured during the last trimester of pregnancy in the cat. Therefore, the feline placenta is capable of synthesising luteolytic PGF2alpha, which enables CL regression and parturition at the end of pregnancy.

L’arthrose (OA) est une maladie dégénérative et multifactorielle caractérisée par une destruction de cartilage, une formation d’ostéophytes et une inflammation au niveau de la membrane synoviale. Le 4-hydroxynonénal (HNE), un produit final de la peroxydation lipidique, a été identifié récemment comme un facteur catabolique et un médiateur inflammatoire dans le cartilage arthrosique humain. Notre projet vise à étudier l’effet du HNE sur la régulation de la prostaglandine E2 synthase-1 microsomale (mPGES-1) et de la protéine activante 5-lipoxygénase (FLAP)/5-lipoxygénase (5-LOX) dans les chondrocytes arthrosiques humains. Lorsque les cellules sont traitées une seule fois avec 10 µM HNE, les résultats de Western blot et de PCR en temps réel montrent que l’expression de la cyclooxygénase-2 (COX-2) et de la mPGES-1 augmente de manière significative et atteint respectivement le maximum après 8 et 16 heures d’incubation puis diminue graduellement. Cependant, lorsque les cellules sont traitées plusieurs fois avec 10 µM HNE à 2 heures d’intervalle, l’expression de la COX-2 et de la mPGES-1 augmente en fonction du temps sans subir une baisse après 24 heures d’incubation. Le HNE induit l’activité du promoteur de la mPGES-1 via l’activation du facteur de transcription Egr-1. L’investigation de la 2ème voie du métabolisme de l’acide arachidonique, à savoir 5-LOX/FLAP, montre que le HNE induit l’expression de FLAP après 24 heures de stimulation et celle de 5-LOX seulement après 48 heures. Ceci semble survenir à l’étape de transcription au cours de laquelle HNE induit l’expression de l’ARNm et l’activité du promoteur du gène 5-LOX. Nous avons démontré aussi que le niveau de leukotriène B4 (LTB4) augmente et suit le même profil que celui de la 5-LOX. L’étude des mécanismes moléculaires susceptibles d’être impliqués dans la régulation de la 5-LOX/FLAP par le HNE montre que ce dernier stimule leur expression via l’action de prostaglandine E2 (PGE2) et du facteur de croissance transformant-beta 1 (TGF-β1). En conclusion, notre étude démontre que le HNE induit à court-terme d’incubation la voie de COX-2/mPGES-1 puis par la suite stimule celle de FLAP/5-LOX à long-terme d’incubation dans les chondrocytes arthrosiques humains. Ces résultats suggèrent que la mPGES-1 et 5-LOX/FLAP sont des potentielles cibles thérapeutiques intéressantes pour contrôler la production de PGE2 et LTB4 dans OA. / 4-hydroxynonenal (HNE), a lipid peroxidation end-product, is produced abundantly in osteoarthritic (OA) articular tissues. Recently, we reported that HNE-induced cyclooxygenase-2 (COX-2) decreased gradually in human OA chondrocytes after 8 h of incubation. This study aimed to investigate whether COX-2 down-regulation is attributed to HNE depletion and is responsible for the switch from COX-2 to 5-lipoxygenase-activating protein (FLAP)/5-lipoxygenase (5-LOX). Treatment of chondrocytes with 10 µM HNE induced prostaglandin E2 (PGE2) release as well as COX-2 and microsomal prostaglandin E2 synthase-1 (mPGES-1) expression at the protein and mRNA levels, with a plateau reached at 8-16 h of incubation, followed by a subsequent decline. However, 8 repeated treatments with 10 µM HNE prevented the reduction of COX-2 and mPGES-1 expression. We demonstrated that HNE induced mPGES-1 promoter activity mainly through transcription factor Egr-1 activation. On the other hand, when COX-2 expression decreased, leukotriene B4 (LTB4) level rose after a long period of stimulation (48 and 72 h). At the mRNA level, HNE induced FLAP and 5-LOX expression after 24 and 48 h of stimulation, respectively. The addition of a nonspecific COX-2 inhibitor (naproxen) to cultured chondrocytes revealed that FLAP and 5-LOX regulation by HNE required PGE2 production. Furthermore, our data showed that 10 µM HNE significantly induced transforming growth factor-beta 1 (TGF-β1) production. The addition of anti-TGF-β antibody to culture medium reduced HNE-induced 5-LOX/FLAP expression by 40%, indicating the involvement of a TGF-β1-dependent mechanism. Our data demonstrate that the shunt to the FLAP/5-LOX pathway in HNE-induced human OA chondrocytes is attributed to COX-2 inhibition, probably due to HNE depletion. PGE2 and TGF-β1 are suggested to be involved in this regulation. Further experiments are in progress to determine other molecular mechanisms underlying this switch in OA chondrocytes.

L’arthrose (OA) est une maladie dégénérative et multifactorielle caractérisée par une destruction de cartilage, une formation d’ostéophytes et une inflammation au niveau de la membrane synoviale. Le 4-hydroxynonénal (HNE), un produit final de la peroxydation lipidique, a été identifié récemment comme un facteur catabolique et un médiateur inflammatoire dans le cartilage arthrosique humain. Notre projet vise à étudier l’effet du HNE sur la régulation de la prostaglandine E2 synthase-1 microsomale (mPGES-1) et de la protéine activante 5-lipoxygénase (FLAP)/5-lipoxygénase (5-LOX) dans les chondrocytes arthrosiques humains. Lorsque les cellules sont traitées une seule fois avec 10 µM HNE, les résultats de Western blot et de PCR en temps réel montrent que l’expression de la cyclooxygénase-2 (COX-2) et de la mPGES-1 augmente de manière significative et atteint respectivement le maximum après 8 et 16 heures d’incubation puis diminue graduellement. Cependant, lorsque les cellules sont traitées plusieurs fois avec 10 µM HNE à 2 heures d’intervalle, l’expression de la COX-2 et de la mPGES-1 augmente en fonction du temps sans subir une baisse après 24 heures d’incubation. Le HNE induit l’activité du promoteur de la mPGES-1 via l’activation du facteur de transcription Egr-1. L’investigation de la 2ème voie du métabolisme de l’acide arachidonique, à savoir 5-LOX/FLAP, montre que le HNE induit l’expression de FLAP après 24 heures de stimulation et celle de 5-LOX seulement après 48 heures. Ceci semble survenir à l’étape de transcription au cours de laquelle HNE induit l’expression de l’ARNm et l’activité du promoteur du gène 5-LOX. Nous avons démontré aussi que le niveau de leukotriène B4 (LTB4) augmente et suit le même profil que celui de la 5-LOX. L’étude des mécanismes moléculaires susceptibles d’être impliqués dans la régulation de la 5-LOX/FLAP par le HNE montre que ce dernier stimule leur expression via l’action de prostaglandine E2 (PGE2) et du facteur de croissance transformant-beta 1 (TGF-β1). En conclusion, notre étude démontre que le HNE induit à court-terme d’incubation la voie de COX-2/mPGES-1 puis par la suite stimule celle de FLAP/5-LOX à long-terme d’incubation dans les chondrocytes arthrosiques humains. Ces résultats suggèrent que la mPGES-1 et 5-LOX/FLAP sont des potentielles cibles thérapeutiques intéressantes pour contrôler la production de PGE2 et LTB4 dans OA. / 4-hydroxynonenal (HNE), a lipid peroxidation end-product, is produced abundantly in osteoarthritic (OA) articular tissues. Recently, we reported that HNE-induced cyclooxygenase-2 (COX-2) decreased gradually in human OA chondrocytes after 8 h of incubation. This study aimed to investigate whether COX-2 down-regulation is attributed to HNE depletion and is responsible for the switch from COX-2 to 5-lipoxygenase-activating protein (FLAP)/5-lipoxygenase (5-LOX). Treatment of chondrocytes with 10 µM HNE induced prostaglandin E2 (PGE2) release as well as COX-2 and microsomal prostaglandin E2 synthase-1 (mPGES-1) expression at the protein and mRNA levels, with a plateau reached at 8-16 h of incubation, followed by a subsequent decline. However, 8 repeated treatments with 10 µM HNE prevented the reduction of COX-2 and mPGES-1 expression. We demonstrated that HNE induced mPGES-1 promoter activity mainly through transcription factor Egr-1 activation. On the other hand, when COX-2 expression decreased, leukotriene B4 (LTB4) level rose after a long period of stimulation (48 and 72 h). At the mRNA level, HNE induced FLAP and 5-LOX expression after 24 and 48 h of stimulation, respectively. The addition of a nonspecific COX-2 inhibitor (naproxen) to cultured chondrocytes revealed that FLAP and 5-LOX regulation by HNE required PGE2 production. Furthermore, our data showed that 10 µM HNE significantly induced transforming growth factor-beta 1 (TGF-β1) production. The addition of anti-TGF-β antibody to culture medium reduced HNE-induced 5-LOX/FLAP expression by 40%, indicating the involvement of a TGF-β1-dependent mechanism. Our data demonstrate that the shunt to the FLAP/5-LOX pathway in HNE-induced human OA chondrocytes is attributed to COX-2 inhibition, probably due to HNE depletion. PGE2 and TGF-β1 are suggested to be involved in this regulation. Further experiments are in progress to determine other molecular mechanisms underlying this switch in OA chondrocytes.

Human skin has distinct lipid metabolism and production of bioactive lipid mediators that can be modulated by nutritional supplementation with omega-3 polyunsaturated fatty acids (n-3 PUFA), of which eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids exert anti-inflammatory effects. The aims of this project were to gain better understanding of their individual mechanisms in human epidermis and dermis. HaCaT keratinocytes, 46BR.1N fibroblasts, primary human epidermal keratinocytes and dermal fibroblasts were treated with EPA or DHA for 72h and then sham-irradiated or exposed to 15 mJ/cm2 ultraviolet radiation (UVR). Viability was measured by the MTT assay. The expression of cyclooxygenase-2 (COX-2), microsomal prostaglandin synthase-1 (mPGES-1) and 15-hydroxyprostaglandin dehydrogenase (15-PGDH) proteins was explored by western blotting. Human skin explants (n=4 donors) were cultured for 3 or 6 days and supplemented with EPA, DHA or vehicle. Culture media were collected to evaluate tissue damage and PUFA cytotoxicity (lactate dehydrogenase assay). Epidermal and dermal lipid profiles were assessed by gas chromatography and liquid chromatography coupled to tandem mass spectrometry. Primary keratinocytes were treated with fatty acids and various lipid mediators for 48h. Their effect was determined by the scratch assay and transepithelial electrical resistance. UVR upregulated COX-2 in HaCaT and primary epidermal keratinocytes, but did not affect mPGES-1 and 15-PGDH protein expression. UVR upregulated COX-2 and mPGES-1 in 46BR.1N fibroblasts but had no effect on 15-PGDH expression. The same UVR dose did not alter the expression of COX-2, mPGES-1 and 15-PGDH in primary dermal fibroblasts. Only EPA attenuated COX-2 expression in HaCaT and primary keratinocytes and either EPA or DHA had any effect in 46BR.1N and primary fibroblasts. Skin explants showed initial post-biopsy tissue damage. EPA and DHA supplementation augmented cellular levels of the corresponding fatty acids in both epidermis and dermis to a different extent. Increased uptake of DHA in the dermis was accompanied by reduced arachidonic acid levels. EPA treatment stimulated the production of PGE3 and various HEPE in epidermis, while DHA treatment caused high levels of HDHA species in dermis. N-3 PUFA and their derivatives delayed wound healing, cell migration and epidermal barrier permeability, while n-6 PUFA lipids showed the opposite effect. Overall, these findings suggest that EPA and DHA differently affect skin cells and skin, with EPA preference in epidermis and DHA in the dermis. These results highlight the importance of differential skin responses that could be important in skin health and disease.