Neutrophil gelatinase-associated lipocalin is an extracellular protein produced mostly in kidney. Recently, it has become a promising biomarker of renal damage in vivo. On the other hand, the validation of NGAL as a biomarker for nephrotoxicity estimation in vitro has not been characterized in detail yet. Since the HK-2 cells are frequently used human kidney cell line, we aimed to characterize the production of NGAL in these cells and to evaluate NGAL as a possible marker of cell impairment. We used heavy metals (mercury, cadmium), peroxide, drugs (acetaminophen, gentamicin) and cisplatin to mimic nephrotoxicity. HK-2 cells were incubated with selected compounds for 1-24h and cell viability was measured together with extracellular NGAL production. We proved that HK-2 cells possess a capacity to produce NGAL in amount of 2pg/ml/h. We found a change in cell viability after 24h incubation with all tested toxic compounds. The largest decrease of the viability was detected in mercury, acetaminophen, cisplatin and gentamicin. Unexpectedly, we found also a significant decrease in NGAL production in HK-2 cells treated with these toxins for 24h: to 11±5%, 54±5%, 57±6% and 76±9% respectively, compared with controls (=100%). Our results were followed with qPCR analysis when we found no significant increase in LCN2 gene expression after 24h incubation. We conclude that extracellular NGAL production negatively correlates with HK-2 cell impairment.
- MeSH
- Acute Kidney Injury chemically induced metabolism MeSH
- Biomarkers metabolism MeSH
- Cell Line MeSH
- Cisplatin toxicity MeSH
- Gentamicins toxicity MeSH
- Cadmium toxicity MeSH
- Humans MeSH
- Lipocalin-2 genetics metabolism MeSH
- Acetaminophen toxicity MeSH
- Mercury toxicity MeSH
- tert-Butylhydroperoxide toxicity MeSH
- Cell Survival drug effects MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
Skin exposure to ultraviolet (UV) light evokes a complex stress response in keratinocytes. Keratin filament organization provides structural stability and mechanical integrity of keratinocytes. Involucrin is a transglutaminase substrate protein contributing to the formation of insoluble cornified envelopes. However, a more complex role for keratins and involucrin has been proposed, including the regulation of cell stress response. The aim was to evaluate modulations of keratin 1, 10 and involucrin expression in HaCaT in the light of the complex response of these cells to UV-B radiation, including effects on c-Jun and matrix metalloproteinase 1 (MMP-1) gene expression and production of interleukin (IL) 6 and 8. A UV-B (300±5 nm) dose of 10 mJ/cm(2) was selected since this dose resulted in a partial decrease in cell viability in contrast to higher UV-B doses, which induced complete cell death 48 h after treatment. The UV-B radiation induced significant expression of keratin 1 and 10 and decreased expression of involucrin. This was accompanied by increased expression of c-Jun and MMP-1 and IL-6 and IL-8 production. The data suggest that the expression of keratin 1, 10 and involucrin is modulated in HaCaT keratinocytes as a part of the complex stress response to UV radiation.
- Publication type
- Journal Article MeSH
Insects tend to feed on related hosts. The phylogenetic composition of host plant communities thus plays a prominent role in determining insect specialization, food web structure, and diversity. Previous studies showed a high preference of insect herbivores for congeneric and confamilial hosts suggesting that some levels of host plant relationships may play more prominent role that others. We aim to quantify the effects of host phylogeny on the structure of quantitative plant-herbivore food webs. Further, we identify specific patterns in three insect guilds with different life histories and discuss the role of host plant phylogeny in maintaining their diversity. We studied herbivore assemblages in three temperate forests in Japan and the Czech Republic. Sampling from a canopy crane, a cherry picker and felled trees allowed a complete census of plant-herbivore interactions within three 0·1 ha plots for leaf chewing larvae, miners, and gallers. We analyzed the effects of host phylogeny by comparing the observed food webs with randomized models of host selection. Larval leaf chewers exhibited high generality at all three sites, whereas gallers and miners were almost exclusively monophagous. Leaf chewer generality dropped rapidly when older host lineages (5-80 myr) were collated into a single lineage but only decreased slightly when the most closely related congeneric hosts were collated. This shows that leaf chewer generality has been maintained by feeding on confamilial hosts while only a few herbivores were shared between more distant plant lineages and, surprisingly, between some congeneric hosts. In contrast, miner and galler generality was maintained mainly by the terminal nodes of the host phylogeny and dropped immediately after collating congeneric hosts into single lineages. We show that not all levels of host plant phylogeny are equal in their effect on structuring plant-herbivore food webs. In the case of generalist guilds, it is the phylogeny of deeper plant lineages that drives the food web structure whereas the terminal relationships play minor roles. In contrast, the specialization and abundance of monophagous guilds are affected mainly by the terminal parts of the plant phylogeny and do not generally reflect deeper host phylogeny.
- MeSH
- Herbivory * MeSH
- Phylogeny * MeSH
- Insecta growth & development physiology MeSH
- Larva physiology MeSH
- Forests * MeSH
- Plant Leaves physiology MeSH
- Magnoliopsida classification MeSH
- Food Chain * MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Czech Republic MeSH
- Japan MeSH
- MeSH
- Cell Membrane metabolism drug effects MeSH
- Rats MeSH
- RNA, Messenger biosynthesis MeSH
- Antibodies, Monoclonal diagnostic use MeSH
- ATP Binding Cassette Transporter, Subfamily B biosynthesis genetics MeSH
- Placenta metabolism MeSH
- Placentation MeSH
- Pregnancy MeSH
- Vesicular Transport Proteins biosynthesis genetics MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Pregnancy MeSH
- Animals MeSH
Liver regeneration in mammals is a unique phenomenon attracting scientific interest for decades. It is a valuable model for basic biology research of cell cycle control as well as for clinically oriented studies of wide and heterogeneous group of liver diseases. This article provides a concise review of current knowledge about the liver regeneration, focusing mainly on rat partial hepatectomy model. The three main recognized phases of the regenerative response are described. The article also summarizes history of molecular biology approaches to the topic and finally comments on obstacles in interpreting the data obtained from large scale microarray-based gene expression analyses.
- MeSH
- Gene Expression MeSH
- Financing, Organized MeSH
- Liver metabolism MeSH
- Humans MeSH
- Liver Regeneration physiology genetics MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Review MeSH
Decades of liver regeneration studies still left the termination phase least elucidated. However regeneration ending mechanisms are clinicaly relevant. We aimed to analyse the timing and transcriptional control of the latest phase of liver regeneration, both controversial. Male Wistar rats were subjected to 2/3 partial hepatectomy with recovery lasting from 1 to 14 days. Time-series microarray data were assessed by innovative combination of hierarchical clustering and principal component analysis and validated by real-time RT-PCR. Hierarchical clustering and principal component analysis in agreement distinguished three temporal phases of liver regeneration. We found 359 genes specifically altered during late phase regeneration. Gene enrichment analysis and manual review of microarray data suggested five pathways worth further study: PPAR signalling pathway; lipid metabolism; complement, coagulation and fibrinolytic cascades; ECM remodelling and xenobiotic biotransformation. Microarray findings pertinent for termination phase were substantiated by real-time RT-PCR. In conclusion, transcriptional profiling mapped late phase of liver regeneration beyond 5th day of recovery and revealed 5 pathways specifically acting at this time. Inclusion of longer post-surgery intervals brought improved coverage of regeneration time dynamics and is advisable for further works. Investigation into the workings of suggested pathways
- MeSH
- Transcription, Genetic MeSH
- Hepatectomy MeSH
- Liver * metabolism MeSH
- Rats MeSH
- Lipid Metabolism MeSH
- Disease Models, Animal MeSH
- Liver Diseases * genetics metabolism veterinary MeSH
- Rats, Wistar MeSH
- Peroxisome Proliferator-Activated Receptors metabolism MeSH
- Liver Regeneration * MeSH
- Gene Expression Regulation MeSH
- Transcriptome * MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Male MeSH
- Animals MeSH
