| 1. |
- Eeva, Tapio, et al.
(författare)
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Geographical trends in the yolk carotenoid composition of the pied flycatcher (Ficedula hypoleuca)
- 2011
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Ingår i: Oecologia. - : Springer Science and Business Media LLC. - 0029-8549 .- 1432-1939. ; 165:2, s. 277-287
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Tidskriftsartikel (refereegranskat)abstract
- Carotenoids in the egg yolks of birds are considered to be important antioxidants and immune stimulants during the rapid growth of embryos. Yolk carotenoid composition is strongly affected by the carotenoid composition of the female's diet at the time of egg formation. Spatial and temporal differences in carotenoid availability may thus be reflected in yolk concentrations. To assess whether yolk carotenoid concentrations or carotenoid profiles show any large-scale geographical trends or differences among habitats, we collected yolk samples from 16 European populations of the pied flycatcher, Ficedula hypoleuca. We found that the concentrations and proportions of lutein and some other xanthophylls in the egg yolks decreased from Central Europe northwards. The most southern population (which is also the one found at the highest altitude) also showed relatively low carotenoid levels. Concentrations of beta-carotene and zeaxanthin did not show any obvious geographical gradients. Egg yolks also contained proportionally more lutein and other xanthophylls in deciduous than in mixed or coniferous habitats. We suggest that latitudinal gradients in lutein and xanthophylls reflect the lower availability of lutein-rich food items in the northern F. hypoleuca populations and in montane southern populations, which start egg-laying earlier relative to tree phenology than the Central European populations. Similarly, among-habitat variation is likely to reflect the better availability of lutein-rich food in deciduous forests. Our study is the first to indicate that the concentration and profile of yolk carotenoids may show large-scale spatial variation among populations in different parts of the species' geographical range. Further studies are needed to test the fitness effects of this geographical variation.
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| 2. |
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| 3. |
- Kaarniranta, Kai, et al.
(författare)
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Geldanamycin activates Hsp70 response and attenuates okadaic acid-induced cytotoxicity in human retinal pigment epithelial cells.
- 2005
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Ingår i: Brain Research. Molecular Brain Research. - : Elsevier. - 0169-328X .- 1872-6941. ; 137:1-2, s. 126-131
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Tidskriftsartikel (refereegranskat)abstract
- Reversible protein phosphorylation regulates the biological activities of many human proteins involved in crucial cellular processes, e.g., protein-protein interactions, cell signaling, gene transcription, cell growth, and death. A malfunction of cellular homeostasis in retinal pigment epithelial (RPE) cells is involved in the age-related retinal degeneration. In this study, we examined cytotoxicity in human RPE cells subjected to the protein phosphatase inhibitor, okadaic acid (OA). Moreover, the influence of Hsp90 inhibitor geldanamycin (GA), a benzoquinone ansamycin, in cytoprotection was assessed. Hsp70 protein levels were analyzed by Western blot. Cellular viability was determined by LDH and MTT assays. To study apoptotic cell death, caspase-3 enzyme activity was measured by assaying the cleavage of a fluorescent peptide substrate and Hoechst dye was used to visualize nuclear morphology. OA treatment caused morphological changes and induced cytotoxicity by caspase-3-independent manner in the RPE cells. No evidence of nuclear fragmentation was observed in response to OA. Interestingly, GA treatment accumulated Hsp70 protein and attenuated OA-induced cytotoxicity. This study suggests that Hsp70 and Hsp90 are closely related to cytoprotection of RPE cells in response to protein phosphatase inhibition.
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| 4. |
- Kaarniranta, Kai, et al.
(författare)
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Geldanamycin increases 4-hydroxynonenal (HNE)-induced cell death in human retinal pigment epithelial cells.
- 2005
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Ingår i: Neuroscience Letters. - : Elsevier. - 0304-3940 .- 1872-7972. ; 382:1-2, s. 185-190
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Tidskriftsartikel (refereegranskat)abstract
- Development of age-related macular degeneration (AMD) is associated with functional abnormalities and cell death in retinal pigment epithelial (RPE) cells attributable to oxidative stress. To minimize the adverse effects of oxidative stress, cells activate their defence systems, e.g., via increased expression of heat shock protein (Hsp), activation of stress sensitive AP-1 and NF-kappaB transcription factors. In this study, we examined the accumulation of Hsp70 protein, activation of AP-1 and NF-kappaB transcription factors in human ARPE-19 cells subjected to a 4-hydroxynonenal (HNE)-induced oxidative stress. In addition, the influence of Hsp90 inhibitor geldanamycin (GA) was studied in HNE-treated cells. Mitochondrial metabolic activity and apoptosis were determined to evaluate cell death in the ARPE-19 cells. The ARPE-19 cells showed increased accumulation of Hsp70 protein before of the cytotoxic hallmarks appearing in response to HNE. In contrast, increased DNA-binding activities of AP-1 or NF-kappaB transcription factors were not seen under HNE insults. Interestingly, GA significantly increased cell death in the HNE-treated cells, which was involved in caspase-3 independent apoptosis. This study reveals that the Hsps have an important role in the cytoprotection of RPE cells subjected to HNE-derived oxidative stress.
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| 5. |
- Kaarniranta, Kai, et al.
(författare)
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Neuronal cells show regulatory differences in the hsp70 gene response.
- 2002
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Ingår i: Brain Research. Molecular Brain Research. - : Elsevier. - 0169-328X .- 1872-6941. ; 101:1-2, s. 136-140
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Tidskriftsartikel (refereegranskat)abstract
- The synthesis of heat shock proteins (Hsps), encoded by heat shock genes, is increased in response to various stress stimuli. Hsps function as molecular chaperones, they dissociate cytotoxic stress-induced protein aggregates within cells and ensure improved survival. Induction of heat shock genes is mainly regulated at the transcriptional level. The stress responsive transcription factor, heat shock factor 1 (HSF1), is involved in the transcriptional induction of the heat shock genes. Our objective was to examine how hsp70 genes are regulated in different transformed and primary neurons upon exposure to elevated temperature. Our findings reveal that the Hsp70 response is regulated at the translational level in Neuro-2a neuroblastoma cells, while the IMR-32 neuroblastoma cells respond to stress by the classical HSF1-driven transcriptional regulatory mechanism. Primary rat hippocampal neurons show a lack of HSF1 and induction of the hsp70 gene. These observations suggest that neuronal cells display different hsp70 gene expression patterns which range from undetected response to transcriptional and posttranscriptional regulation during heat stress.
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| 6. |
- Kaarniranta, Kai, et al.
(författare)
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Silmäpohjan rappeumatauti - vaikea ongelma lääkärille [Age-related macular degeneration--a difficult problem for the patient and for the ophthalmologist].
- 2003
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Ingår i: Duodecim. - 0012-7183 .- 2242-3281. ; 119:10, s. 935-942
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Tidskriftsartikel (refereegranskat)abstract
- Silmänpohjan ikärappeuma on yleisin näkövammaisuutta aiheuttava silmäsairaus länsimaissa. Yli 65-vuotiaista 10–20 % kärsii sen aiheuttamista keskeisen näköalueen korjaantumattomista häiriöistä. Väestön vanhetessa ikärappeuman esiintyvyys on lisääntynyt. Sairauden kliiniset ja histopatologiset muutokset tunnetaan hyvin, mutta etiologia on tuntematon, ehkäisystä on niukasti tietoa ja hoitovaihtoehdot ovat vähäiset. Silmänpohjan ikärappeumasta on muodostunut yksi vaikeimmista ongelmista silmälääkäreille ja oftalmologian tutkijoille.
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| 7. |
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| 8. |
- Ruuskanen, Suvi, et al.
(författare)
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Geographical Variation in Egg Mass and Egg Content in a Passerine Bird
- 2011
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 6:11, s. e25360-
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Tidskriftsartikel (refereegranskat)abstract
- Reproductive, phenotypic and life-history traits in many animal and plant taxa show geographic variation, indicating spatial variation in selection regimes. Maternal deposition to avian eggs, such as hormones, antibodies and antioxidants, critically affect development of the offspring, with long-lasting effects on the phenotype and fitness. Little is however known about large-scale geographical patterns of variation in maternal deposition to eggs. We studied geographical variation in egg components of a passerine bird, the pied flycatcher (Ficedula hypoleuca), by collecting samples from 16 populations and measuring egg and yolk mass, albumen lysozyme activity, yolk immunoglobulins, yolk androgens and yolk total carotenoids. We found significant variation among populations in most egg components, but ca. 90% of the variation was among individuals within populations. Population however explained 40% of the variation in carotenoid levels. In contrast to our hypothesis, we found geographical trends only in carotenoids, but not in any of the other egg components. Our results thus suggest high within-population variation and leave little scope for local adaptation and genetic differentiation in deposition of different egg components. The role of these maternally-derived resources in evolutionary change should be further investigated.
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| 9. |
- Salminen, Antero, et al.
(författare)
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Emerging role of p62/sequestosome-1 in the pathogenesis of Alzheimer's disease
- 2012
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Ingår i: Progress in Neurobiology. - : Elsevier BV. - 0301-0082 .- 1873-5118. ; 96:1, s. 87-95
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Forskningsöversikt (refereegranskat)abstract
- The p62/sequestosome-1 is a multifunctional protein containing several protein-protein interaction domains. Through these interactions p62 is involved in the regulation of cellular signaling and protein trafficking, aggregation and degradation. p62 protein can bind through its UBA motif to ubiquitinated proteins and control their aggregation and degradation via either autophagy or proteasomes. p62 protein has been reported to be seen in association with the intracellular inclusions in primary and secondary tauopathies, α-synucleinopathies and other neurodegenerative brain disorders displaying inclusions with misfolded proteins. In Alzheimer's disease (AD), p62 protein is associated with neurofibrillary tangles composed primarily of hyperphosphorylated tau protein and ubiquitin. Increasing evidence indicates that p62 has an important role in the degradation of tau protein. The lack of p62 protein expression provokes the tau pathology in mice. Recent studies have demonstrated that the p62 gene expression and cytoplasmic p62 protein levels are significantly reduced in the frontal cortex of AD patients. Decline in the level of p62 protein can disturb the signaling pathways of Nrf2, cyclic AMP and NF-κB and in that way increase oxidative stress and impair neuronal survival. We will review here the molecular and functional characteristics of p62 protein and outline its potential role in the regulation of Alzheimer's pathogenesis.
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| 10. |
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