A fotoreceptor-fejlődés sejt- és molekuláris biológiája = Cell and molecular biology of photoreceptor development

Az opszinváltás szabályozása fajonként eltérő, tiroxin és TRbéta2 nélkülözhetetlen a zöld csapfejlődéshez. A receptormegoszlás időbeli és térbeli mintázatával igazoltuk a tiroxint mediáló TRbéta2 szerepét. Tenyésztő módszerünkkel a fotoreceptor-differenciálódás szérummentes környezetben is végbemegy, a világon először definitív médiumban vizsgálható. Más faktorok (A- és E-vitamin, BDNF) is hatnak a pigment-expresszióra. Szelektív neurotrophin antagonisták az opszin és a TrkB receptor kapcsoltságára utalnak. Az erythropoietin retinális expressziója HIF1-α szabályozás alatt áll és időben változik a fejlődés korai szakaszában. Szemnyitás után a retinában lecsökken a transzdukciós molekulák szintje, kivéve a fotoreceptorokat. A sejttestben szintetizálódnak, közös lipid rafton kerülnek a kültagba és játszanak szerepet a fejlődésben. Az STK38L gén homozigóta mutációja befolyásolja a fotoreceptor-fejlődést. Sejthalál és proliferáció egyaránt jelen van. Hibrid sejtek jelennek meg pálcika-, kisebb mértékben S-opszin termeléssel. A differenciált, mutáns sejtek a degenerációs gén hatására megőrzik osztódóképességüket. A melatonin éjszaka termelődik, éjjeli világítás a hormontermelés gátlásával patológiás folyamatokat (emlő és colorectalis carcinoma) okozhat. A pineális szerv emlősben elvesztette fotoreceptor működését és szimpatikus rostokon a retinából kap információt. Mivel a pineális melatoninképzést rövidhullámú fény gátolja, éjjeli műszakban hosszúhullámú megvilágítást kell használni. | Regulation of opsin-switch varies across species. Thyroxin and TRß2 receptor is essential for green cone development. Spatial and temporal receptor distribution proved the role of TRß2 mediating thyroxin. Photoreceptor differentiation is completed in our culture method in serum-free medium, allowing its examination in a definitive paradigm. Other factors such as Vitamins A and E, BDNF) also influence visual pigment expression. Selective neurotrophin antagonists reveal the close connection of opsin and Trkß. Retinal expression of erythropoietin is under the regulation of HIF1-α, and changes during development. Transduction molecule levels decrease after eye opening, except for photoreceptors. They are synthesized in the cell body, located and transported in the outer segment on common lipid rafts and play a developmental role. Homozygotic mutation of STK38L influences photoreceptor development. Cell death and proliferation are equally present. Hybrid photoreceptors appear that express rod and, to a lesser extent, S-opsin. The degenerated, hybrid mutants retain their capacity to divide. Melatonin is produced at night. Nocturnal light exposition inhibiting hormone production may generate pathological processes (e.g.: carcinomas). The pineal organ in mammals has lost its photoreceptor function and receives information from the retina via sympathetic fibers. Since short wave light inhibits melatonin production, long-wave illumination is recommended during night-shift

Localization of Caveolin-1 and C-Src in Mature and Differentiating Photoreceptors: Raft Proteins Co-Distribute with Rhodopsin During Development

Numerous biochemical and morphological studies have provided insight into the distribution pattern of caveolin-1 and the presence of membrane rafts in the vertebrate retina. To date however, studies have not addressed the localization profile of raft specific proteins during development. Therefore the purpose of our studies was to follow the localization pattern of caveolin-1, phospho-caveolin-1 and c-src in the developing retina and compare it to that observed in adults. Specific antibodies were used to visualize the distribution of caveolin-1, c-src, a kinase phosphorylating caveolin-1, and phospho-caveolin-1. The labeling pattern of this scaffolded complex was compared to those of rhodopsin and rhodopsin kinase. Samples were analyzed at various time points during postnatal development and compared to adult retinas. The immunocytochemical studies were complemented with immunoblots and immunoprecipitation studies. In the mature retina caveolin-1 and c-src localized mainly to the cell body and IS of photoreceptors, with only very weakly labeled OS. In contrast, phospho-caveolin-1 was only detectable in the OS of photoreceptors. During development we followed the expression and distribution profile of these proteins in a temporal sequence with special attention to the period when OS formation is most robust. Double labeling immunocytochemistry and immunoprecipitation showed rhodopsin to colocalize and co-immunoprecipitate with caveolin-1 and c-src. Individual punctate structures between the outer limiting membrane and the outer plexiform layer were seen at P10 to be labeled by both rhodopsin and caveolin-1 as well as by rhodopsin and c-src, respectively. These studies suggest that membrane raft specific proteins are co-distributed during development, thereby pointing to a role for such complexes in OS formation. In addition, the presence of small punctate structures containing caveolin-1, c-src and rhodopsin raise the possibility that these proteins may transport together to OS during development and that caveolin-1 exists predominantly in a phosphorylated form in the OS. © 2011 Springer Science+Business Media B.V

Localization of Caveolin-1 and C-Src in Mature and Differentiating Photoreceptors: Raft Proteins Co-Distribute With Rhodopsin During Development

Numerous biochemical and morphological studies have provided insight into the distribution pattern of caveolin-1 and the presence of membrane rafts in the vertebrate retina. To date however, studies have not addressed the localization profile of raft specific proteins during development. Therefore the purpose of our studies was to follow the localization pattern of caveolin-1, phospho-caveolin-1 and c-src in the developing retina and compare it to that observed in adults. Specific antibodies were used to visualize the distribution of caveolin-1, c-src, a kinase phosphorylating caveolin-1, and phospho-caveolin-1. The labeling pattern of this scaffolded complex was compared to those of rhodopsin and rhodopsin kinase. Samples were analyzed at various time points during postnatal development and compared to adult retinas. The immunocytochemical studies were complemented with immunoblots and immunoprecipitation studies. In the mature retina caveolin-1 and c-src localized mainly to the cell body and IS of photoreceptors, with only very weakly labeled OS. In contrast, phospho-caveolin-1 was only detectable in the OS of photoreceptors. During development we followed the expression and distribution profile of these proteins in a temporal sequence with special attention to the period when OS formation is most robust. Double labeling immunocytochemistry and immunoprecipitation showed rhodopsin to colocalize and co-immunoprecipitate with caveolin-1 and c-src. Individual punctate structures between the outer limiting membrane and the outer plexiform layer were seen at P10 to be labeled by both rhodopsin and caveolin-1 as well as by rhodopsin and c-src, respectively. These studies suggest that membrane raft specific proteins are co-distributed during development, thereby pointing to a role for such complexes in OS formation. In addition, the presence of small punctate structures containing caveolin-1, c-src and rhodopsin raise the possibility that these proteins may transport together to OS during development and that caveolin-1 exists predominantly in a phosphorylated form in the OS. © 2011 Springer Science+Business Media B.V

A relatív légnedvesség városi keresztmetszet menti éjszakai eloszlásának vizsgálata esettanulmányok segítségével, Szegeden = Case studies on the nocturnal distribution of relative air humidity along a representative urban cross-section, in Szeged

Based on the mobile measurements carried out between April 2002 and March 2003 in Szeged (Hungary), we examine the influence of urban and meteorological factors on relative air humidity. Besides its relevance in urban climatology, present results can be utilized in human comfort investigations as well. The city of 160,000 inhabitants is situated in the south-eastern part of Hungary at 79 m above sea level on a flat plain with no large water bodies nearby. The described environmental conditions make this town a suitable place for studying an almost undisturbed urban climate. In the present work we use a ca. 10 km long representative cross-section of the urban area consisting of every characteristic land-use type of Szeged. Applying some case studies, tasks include determination and demonstration of the nocturnal peculiarity of air humidity as a function of urban (ratio of built-up area, distance from the centre), meteorological (temperature, wind speed, cloudiness, surface covered by snow) and anthropogenic factors, respectively. As the results show, strong connection can be detected not only between air humidity and the above-mentioned parameters, but also between air humidity as well as the development of urban heat island