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The SNARE machinery is involved in apical plasma membrane trafficking in MDCK cells.
We have investigated the controversial involvement of components of the SNARE (soluble N-ethyl maleimide-sensitive factor [NSF] attachment protein [SNAP] receptor) machinery in membrane traffic to the apical plasma membrane of polarized epithelial (MDCK) cells. Overexpression of syntaxin 3, but not of syntaxins 2 or 4, caused an inhibition of TGN to apical transport and apical recycling, and leads to an accumulation of small vesicles underneath the apical plasma membrane. All other tested transport steps were unaffected by syntaxin 3 overexpression. Botulinum neurotoxin E, which cleaves SNAP-23, and antibodies against alpha-SNAP inhibit both TGN to apical and basolateral transport in a reconstituted in vitro system. In contrast, we find no evidence for an involvement of N-ethyl maleimide-sensitive factor in TGN to apical transport, whereas basolateral transport is NSF-dependent. We conclude that syntaxin 3, SNAP-23, and alpha-SNAP are involved in apical membrane fusion. These results demonstrate that vesicle fusion with the apical plasma membrane does not use a mechanism that is entirely unrelated to other cellular membrane fusion events, but uses isoforms of components of the SNARE machinery, which suggests that they play a role in providing specificity to polarized membrane traffic
Az „osztály halála” Tamás Gáspár Miklós és az értékkritikai iskola szemléletének tükrében
Tanulmányomban az „osztályok halála” diskurzust, ezen belĂĽl is Ulrich Beck kockázattársadalom koncepciĂłját vizsgálom az Ă©rtĂ©kkritikai Marx-olvasat tĂĽkrĂ©ben. Moishe Postone Ă©s Tamás Gáspár MiklĂłs meglátásaira alapozva egy olyan Ă©rtelmezĂ©st mutatok be, amely lehetĹ‘sĂ©get ad kĂ©t kĂĽlönbözĹ‘, a „hagyományos” Ă©s az „értĂ©kkritikai” Marx közötti kĂĽlönbsĂ©gtĂ©telre. ElĹ‘bbi kifejezĂ©ssel azok az elmĂ©letek jelölhetĹ‘k, amelyek a kapitalizmust a magántulajdonban gyökerezĹ‘, piac által közvetĂtett osztályviszonyok terminusaiban ragadják meg, illetve az uralom kategĂłriáját fĹ‘kĂ©pp az osztályelnyomás fogalmai mentĂ©n határozzák meg. Az Ă©rtĂ©kkritikai nĂ©zĹ‘pont ezzel szemben az Ă©rtĂ©k Ă©s az absztrakt munka kritikai elemzĂ©sĂ©n keresztĂĽl ragadja meg a kapitalizmus struktĂşráját. Ezáltal olyan absztrakt uralmi formát feltĂ©telez, amely az Ă©rtĂ©k Ă©s az Ă©rtĂ©ktermelĹ‘ munka törtĂ©netileg specifikus társadalmi formáira vezethetĹ‘ vissza. Amellett Ă©rvelek, hogy a kĂ©sei Marx által használt osztálysĂ©ma elsĹ‘sorban a kapitalizmus strukturális sajátosságait ragadja meg Ă©s nem a kĂĽlönbözĹ‘ társadalmi csoportok szociokulturális aspektusainak, illetve egyenlĹ‘tlen viszonyainak feltĂ©rkĂ©pezĂ©sĂ©re szolgál. Ulrich Beck Ă©s az osztály halála mellett Ă©rvelĹ‘k releváns Ă©szrevĂ©teleket fogalmaznak meg a javak elosztásával Ă©s az ehhez kapcsolĂłdĂł társadalmi jelensĂ©gekkel kapcsolatban, e kritikák viszont csupán a hagyományos marxizmusra vonatkoztathatĂłk
Fetal Epidermal Differentiation and Barrier Development In Vivo is Accelerated by Nuclear Hormone Receptor Activators1
Nuclear receptors which interact with the retinoid X receptor are involved in the regulation of epidermal differentiation and development. We have recently shown that activators of the peroxisome proliferator-activated receptor and of the farnesoid X-activated receptor accelerate epidermal barrier maturation in fetal rat skin in vitro. In this study we asked whether cutaneous development in utero was affected by peroxisome proliferator-activated receptor or farnesoid X-activated receptor activators, or by an activator of another retinoid X receptor partner, liver X receptor. Activators of the peroxisome proliferator-activated receptor (clofibrate or linoleic acid), farnesoid X-activated receptor (farnesol or juvenile hormone III), or liver X receptor (22R-hydroxycholesterol), were injected into the amniotic fluid of fetal rats on gestational day 17. Fetal epidermal barrier function and morphology was assessed on day 19. Whereas vehicle-treated fetal rats displayed no measurable barrier (transepidermal water loss > 10 mg per cm2 per h), a measurable barrier was induced by the intra-amniotic administration of all activators tested (transepidermal water loss range 4.0–8.5 mg per cm2 per h). By light microscopy, control pups lacked a well-defined stratum corneum, whereas a distinct stratum corneum and a thickened stratum granulosum were present in treated pups. By electron microscopy, the extracellular spaces of the stratum corneum in control pups revealed a paucity of mature lamellar unit structures, whereas these structures filled the stratum corneum interstices in treated pups. Additionally, protein and mRNA levels of loricrin and filaggrin, two structural proteins of stratum corneum, were increased in treated epidermis, as were the activities of two lipid catabolic enzymes critical to stratum corneum function, β-glucocerebrosidase and steroid sulfatase. Finally, peroxisome proliferator-activated receptor-α and -δ and liver X receptor-α and -β mRNAs were detected in fetal epidermis by reverse transcriptase–polymerase chain reaction and northern analyses. The presence of these receptors and the ability of their activators to stimulate epidermal barrier and stratum corneum development suggest a physiologic role for peroxisome proliferator-activated receptor and liver X receptor and their endogenous ligands in the regulation of cutaneous development
Effect of fenofibrate on microcirculation and wound healing in healthy and diabetic mice
<p>Abstract</p> <p>Objective</p> <p>Disturbances in wound healing in patients with hyperglycaemic blood sugar values are a common clinical problem. Recent studies identified PPARα-ligands as potential skin therapeutic agents. The aim of this study was to investigate the effects of oral fenofibrate treatment on dermal wound healing and micro-circulatory parameters in diabetic mice.</p> <p>Methods</p> <p>Dermal wounds were created in CD-1 mice. Mice were randomized into four treatment groups: diabetic mice treated (dbf) or not-treated with fenofibrate (dbnf). As controls served non-diabetic mice treated (ndf) or not-treated with fenofibrate (ndnf). At various points in time microcirculation was analyzed by intravital fluorescent microscopy to determine wound surface area, vessel diameter, plasma leakage, functional capillary density, and leukocyte/endothelium interaction.</p> <p>Results</p> <p>The dbf-mice showed a significantly increased diameter of the venules and the arterioles up to 3 days after wound creation compared to dbnf-mice. However, wound healing was not improved in dbf-compared to dbnf-mice. Surprisingly, all microcirculatory parameter (vessel diameter, plasma leakage and functional capillary density) were not deteriorated in dbnf-compared to ndnf-mice.</p> <p>Conclusion</p> <p>We confirm that high blood sugar values lead to a delayed wound healing, but this could not traced back to altered microcirculatory patterns. Furthermore, in dbf-mice an improved vasodilatatory function of small vessels could be detected, but with no substantial effect on wound healing. Further studies are needed to clarify, if topical application of fenofibrate might be beneficial.</p
Peroxisome proliferator-activated receptor agonists (PPARs): a promising prospect in the treatment of psoriasis and psoriatic arthritis
Szegénység, liberális kormányzás és társadalmi struktúra
Tanulmányomban a társadalmi struktĂşra koncepciĂłinak törtĂ©neti alakulásával Ă©s elmĂ©leti alapjaival foglalkozom. Arra keresem a választ, hogy a statisztikai apparátusok Ă©s politikai gondolkodĂłk mikĂ©nt hoztak lĂ©tre kĂĽlönbözĹ‘ kategĂłriákat a társadalmi struktĂşra ábrázolására a 18–19. században Ă©s ezek mikĂ©nt viszonyulnak – Michel Foucault fogalmai alapján – a biopolitika Ă©s a „kormányzatiság” aspektusaihoz. PĂ©ldakĂ©nt a korabeli Anglia társadalmának jellemzĹ‘ivel foglalkozom, Ă©s az osztályszerkezet kategĂłriáinak kialakĂtására fĂłkuszálok jelesĂĽl, hogy milyen társadalmi környezetben hozták lĂ©tre ezeket, Ă©s ez milyen mĂłdon kapcsolĂłdik a nĂ©pessĂ©g kormányozhatĂłságának kĂ©rdĂ©seihez. A hangsĂşlyt a szegĂ©nysĂ©g kezelĂ©sĂ©ben bekövetkezett változásokra helyezve mutatom be, hogy a kormányzatiság milyen szempontokkal szolgálhat a társadalmi struktĂşra elemzĂ©sĂ©hez. Ennek bemutatásához leginkább Mitchell Dean Ă©s Polányi Károly elemzĂ©seire támaszkodom; e kĂ©t szerzĹ‘ gondolatai alapján szemlĂ©ltetem, hogy mikĂ©nt alakultak át azok a szempontok, amelyek alapján a szegĂ©nyeket Ă©s a társadalom egyĂ©b kĂĽlönbözĹ‘ szegmenseit csoportokba, illetve osztályokba rendeztĂ©k, s ez hogyan kapcsolĂłdott a korabeli bĂ©rmunkás, illetve ipari munkavállalĂłi „életforma” lĂ©trehozásához, továbbá a „liberális kormányzás” aspektusaihoz. Amellett Ă©rvelek, hogy biopolitikai struktĂşraelmĂ©letekkĂ©nt Ă©rtelmezhetĹ‘k azok a megközelĂtĂ©sek, amelyek a liberális kormányzás szempontjai alapján formálĂłdnak Ă©s a szociokulturális, illetve szocioökonĂłmiai egyenlĹ‘tlensĂ©geket az önszabályozĂł piac működĂ©si keretein belĂĽl vizsgálják
Occurrence of leucocytes in the intracellular granules in the enterocytes of the jejunum of newborn pigs
Lenten cell: Ultrastructure, absorptive properties, and enzyme expression of a novel type of cell in the newborn and suckling pig intestinal epithelium
Topical Peroxisome Proliferator Activated Receptor-α Activators Reduce Inflammation in Irritant and Allergic Contact Dermatitis Models11The authors declared no conflict of interest.
Peroxisome proliferator activated receptor-α agonists suppress transforming growth factor-α-induced matrix metalloproteinase-9 expression in human keratinocytes
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