Transcriptional changes in ascorbate-glutathione cycle under drought conditions

Ascorbate-glutathione cycle has an important role in defensive processes against oxidative damage generated by drought stress. Changes in expression patterns, subjected to reduced amount of irrigation solution, of ascorbate peroxidase (APX), monodehydroascorbate reductase (MDAR) and dehydroascorbate reductase (DHAR) as enzyme families of this cycle were studied comparing a drought tolerant (Triticum aestivum cv. Plainsman V) and a drought sensitive (Triticum aestivum cv. Cappelle Desprez) wheat genotype. Relative transcript level of isoenzymes localized in distinct subcellular organelles showed significant differences between the two genotypes at the beginning of treatment. Among APX isoenzymes, a thylakoid-bound (tAPX), two stromal (sAPX1, sAPX2), one of the two cytosolic (cAPX1) and a peroxisomal (mAPX) APXs displayed higher relative transcript level in the drought tolerant genotype. The same was observed in case of cytosolic (cDHAR) and stromal (sDHAR) DHARs. However, relative transcript levels of MDHAR isoenzymes were similar in both genotypes. Under drought conditions, the initial relative transcript levels of distinct isoenzymes changed differently comparing the two genotypes leading to the final conclusion that the drought tolerant genotype up-regulates mostly the cytosolic APXs and MDARs to maintain the cellular ascorbate redox state, however in the drought sensitive genotype, sAPX and sDHAR are induced to fill the same function

Regulatory Networks Contributing to Psoriasis Susceptibility

The non-involved, healthy-looking skin of psoriatic pa- tients displays inherent characteristics that make it pro- ne to develop typical psoriatic symptoms. Our primary aim was to identify genes and proteins that are diffe- rentially regulated in the non-involved psoriatic and the normal epidermis, and to discover regulatory networks responsible for these differences. A cDNA microarray ex- periment was performed to compare the gene expression proiles of 4 healthy and 4 psoriatic non-involved epider- mis samples in response to T-cell lymphokine induction in organotypic cultures. We identiied 61 annotated genes and another 11 expressed transcripts that were differen- tially regulated in the psoriatic tissues. Bioinformatics analysis suggested that the regulation of cell morpholo- gy, development and cell death is abnormal, and that the metabolism of small molecules and lipids is differentially regulated in psoriatic epidermis. Our results indicate that one of the early steps of psoriasis pathogenesis may be the abnormal regulation of IL-23A and IL-1B genes in psoriatic keratinocytes. Key words: non-involved psoriatic epidermis; T-cell lymphokines; gene expression analysis; regulatory networks; IL-23A

PPIG, SFRS-18 és LUC7L3 Splicing regulárok vizsgálata szinkronizált, immortalizált sejtvonalakban és pikkelysömörben

Az mRNS érés (splicing) folyamatának vizsgálata egészen újfajta megközelítésnek számít a pikkelysömör kutatásban: a splicing mechanizmus e betegségben tapasztalt eltéréseiről mindössze néhány közlemény jelent meg napjainkig. Egy nemrég elvégzett microarray vizsgálatban több olyan gént is azonosítottunk, amelyek T-limfokin kezelés hatására eltérő kifejeződés változással reagálnak, majd bioinformatikai módszerekkel tovább elemeztük azokat. A gének között három olyat is találtunk (serine/ arginine-rich splicing factor 18 (SFRS18), peptydilpropyl isomerase G (PPIG), luc-7 like 3 (LUC7L3)) amelyek funkciója az mRNS érés szabályozásához kötődik. A PPIG, SFRS18 és LUC7L3 gének kifejeződését szinkronizált, immortalizált sejtvonalak segítségével követtük. Két független sejtvonal (HaCaT és HPV-KER) esetében is azt tapasztaltuk, hogy a splicing regulátorok kifejeződési mintázata jelentős hasonlóságot mutat. Ezekből az eredményekből arra következtettünk, hogy a gének upstream regulációja közös transzkripciós faktorok útján valósulhat meg. A splicing gének fehérjeszintű expresszióját is meghatároztuk Western blot technika segítségével. Előkísérleteinkben azt találtuk, hogy az SFRS18 és a PPIG expressziója fehérje szinten is hasonlóságot mutat a szinkronizált, immortalizált HPV-KER sejtekben. Az in vitro analízisek mellett egészséges és pikkelysömörös betegekből származó tünetes és tünetmentes mintákon is megvizsgáltuk, miként alakul a három fehérje expressziója. Kísérleteink során megmutattuk, hogy a PPIG fehérje expressziós mintázata és kifejeződésének mennyisége is jelentősen megváltozik: a tünetmentes bőrben a PPIG festődése fokozottnak mutatkozott és eloszlása is eltér az egészséges bőrétől. Eredményeink alapján úgy gondoljuk, hogy a splicing szabályozás eltéréseinek fontos szerepe lehet a pikkelysömör tüneteinek kifejlődésében. A splicing folyamatának további tanulmányozása nagyban segítheti a betegség komplex molekuláris hátterének megértését

COP1 Contributes to UVB-Induced Signaling in Human Keratinocytes

UVB irradiation has been shown to trigger a broad range of changes in gene expression in human skin; however, factors governing these events are still not well understood. In this study, we show that human constitutive photomorphogenic protein-1 (huCOP1), an E3 ligase, contributes to the orchestration of UVB response of keratinocytes. Accordingly, our data show that (i) huCOP1 protein is expressed both in the nucleus and in the cytoplasm of cultured keratinocytes, (ii) UVB reduces the levels of the huCOP1 mRNA and protein, and (iii) induces changes in the subcellular localization of huCOP1. Finally, we show that gene-specific silencing of huCOP1 induces the accumulation of the tumor suppressor p53 protein, which is further increased after UVB irradiation

Detection of enteric viral and bacterial pathogens associated with paediatric diarrhoea in Goroka, Papua New Guinea

Objectives: The aim of this study was to investigate the viral and bacterial causes of acute watery diarrhoea in hospitalized children in Papua New Guinea. Methods: A retrospective analysis was conducted on stool samples collected from 199 children (age < 5 years) admitted to the paediatric ward of Goroka General Hospital from August 2009 through November 2010. A large range of viral and bacterial enteric pathogens were targeted using real-time PCR/RT-PCR assays. Results: Young children were much more likely to be admitted with acute gastroenteritis, with 62.8% of patients aged <1 year and 88.4% aged <2 years. An enteric pathogen was detected in 69.8% (n = 138) of patients. The most commonly detected pathogens were Shigella spp (26.6%), rotavirus (25.6%), adenovirus types 40/41 (11.6%), enterotoxigenic Escherichia coli (11.1%), enteropathogenic E. coli (8.5%), norovirus G2 (6.0%), and Campylobacter spp (4.0%). Norovirus G1, sapovirus, and Salmonella spp were also detected, but below our statistical limit of detection. Vibrio cholerae and astrovirus were not detected in any patients. Mixed infections were detected in 22.1% of patients, with Shigella and rotavirus most commonly detected in co-infections with other pathogens. Conclusions: This study demonstrates that Shigella and rotavirus are the major pathogens associated with acute paediatric gastroenteritis in this setting

Splicing regulation disturbances in psoriasis pathogenesis

In a recently performed cDNA microarray experiment we identified three splicing regulators (serine/arginine-rich splicing factor 18 (SFRS18), peptydilpropyl isomerase G (PPIG), luc-7 like3 (LUC7L3) that where differentially expressed in response to T-lymphokines in healthy and psoriatic non-involved epidermis samples. We and others have previously shown that the oncofetal splice variant of fibronectin - the isoform containing the EDA domain (EDA+) - is overexpressed in psoriatic non-involved epidermis. In this study we investigated whether SFRS18, LUC7L3 and PPIG are able to alter the ratio of the normal (EDA-) and psoriasis-associated (EDA+) variant. To this aim the expressions of the splicing regulators were silenced in immortalized keratinocytes (HPV-KER). We found that the EDA+/EDA- ratio was altered upon silencing of LUC7L3 and PPIG: before silencing the expression level of EDA+ fibronectin isoform was higher than the EDA- fibronectin, but as a result of silencing the amount of the two splice variants became comparable. In addition, the expression patterns of the splicing regulators were compared in two different synchronized, immortalized cell lines, HaCaT and HPV-KER cells. Gene and protein expression patterns of the three regulators were very similar in both cell lines during their proliferation and differentiation suggesting that they may share common regulation