| 1. |
- Altmae, Signe, et al.
(author)
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Endometrial transcriptome analysis indicates superiority of natural over artificial cycles in recurrent implantation failure patients undergoing frozen embryo transfer
- 2016
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In: Reproductive BioMedicine Online. - : Elsevier BV. - 1472-6483 .- 1472-6491. ; 32:6, s. 597-613
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Journal article (peer-reviewed)abstract
- Little consensus has been reached on the best protocol for endometrial preparation for frozen embryo transfer (FET). It is not known how, and to what extent, hormone supplementation in artificial cycles influences endometrial preparation for embryo implantation at a molecular level, especially in patients who have experienced recurrent implantation failure. Transcriptome analysis of 15 endometrial biopsy samples at the time of embryo implantation was used to compare two different endometrial preparation protocols, natural versus artificial cycles, for FET in women who have experienced recurrent implantation failure compared with fertile women. IPA and DAVID were used for functional analyses of differentially expressed genes. The TRANSFAC database was used to identify oestrogen and progesterone response elements upstream of differentially expressed genes. Cluster analysis demonstrated that natural cycles are associated with a better endometrial receptivity transcriptome than artificial cycles. Artificial cycles seemed to have a stronger negative effect on expression of genes and pathways crucial for endometrial receptivity, including ESR2, FSHR, LEP, and several interleukins and matrix metalloproteinases. Significant overrepresentation of oestrogen response elements among the genes with deteriorated expression in artificial cycles (P < 0.001) was found; progesterone response elements predominated in genes with amended expression with artificial cycles (P = 0.0052).
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| 2. |
- Kilk, Kalle, et al.
(author)
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Evaluation of transportan 10 in PEI mediated plasmid delivery assay
- 2005
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In: Journal of Controlled Release. - : Elsevier BV. - 0168-3659 .- 1873-4995. ; 103:2, s. 511-23
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Journal article (peer-reviewed)abstract
- Cell-penetrating peptides (CPPs) are novel high-capacity delivery vectors for different bioactive cargoes. We have evaluated the CPP transportan 10 (TP10) as a delivery vector in different in vitro plasmid delivery assays. Tested methods include: TP10 crosslinked to a plasmid via a peptide nucleic acid (PNA) oligomer, TP10 conjugation with polyethyleneimine (PEI), and addition of unconjugated TP10 to standard PEI transfection assay. We found that without additional DNA condensing agents, TP10 has poor transfection abilities. However, the presence of TP10 increases the transfection efficiency several folds compared to PEI alone. At as low concentrations as 0.6 nM, TP10–PNA constructs were found to enhance plasmid delivery up to 3.7-fold in Neuro-2a cells. Interestingly, the transfection efficiency was most significant at low PEI concentrations, allowing reduced PEI concentration without loss of gene delivery. No increase in cytotoxicity due to TP10 was observed and the uptake mechanism was determined to be endocytosis, as previously reported for PEI mediated transfection. In conclusion, TP10 can enhance PEI mediated transfection at relatively low concentrations and may help to develop future gene delivery systems with reduced toxicity.
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| 3. |
- Kokaia, Zaal, et al.
(author)
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Brain insults in rats induce increased expression of the BDNF gene through differential use of multiple promoters
- 1994
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In: European Journal of Neuroscience. - : Wiley. - 1460-9568 .- 0953-816X. ; 6:4, s. 587-596
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Journal article (peer-reviewed)abstract
- The rat brain-derived neurotrophic factor (BDNF) gene consists of four short 5'-exons linked to separate promoters and one 3'-exon encoding the mature BDNF protein. Using in situ hybridization we demonstrate here that kindling-induced seizures, cerebral ischaemia and insulin-induced hypoglycaemic coma increase BDNF mRNA levels through insult- and region-specific usage of three promoters within the BDNF gene. Both brief (2 min) and longer (10 min) periods of forebrain ischaemia induced significant and major increases only of exon III mRNA in the dentate gyrus. Following hypoglycaemic coma (1 and 30 min), exon III mRNA was markedly elevated in the dentate gyrus and, in addition, exon I mRNA showed a moderate increase. Single and recurrent (n = 40) hippocampal seizures significantly increased expression of exon I, II and III mRNAs in the dentate gyrus granule cells. After recurrent seizures, including generalized convulsions, there were also major increases of both exon I and III mRNAs in the CA3 region, amygdala, piriform cortex and neocortex, whereas in the hippocampal CA1 sector marked elevations were detected only for exon III mRNA. The insults had no effect on the level of exon IV mRNA in the brain. The region- and insult-specific pattern of promoter activation might be of importance for the effectiveness of protective responses as well as for the regulation of plastic changes following brain insults.
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| 4. |
- Kokaia, Zaal, et al.
(author)
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Co-expression of TrkB and TrkC receptors in CNS neurones suggests regulation by multiple neurotrophins
- 1995
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In: NeuroReport. - : Ovid Technologies (Wolters Kluwer Health). - 1473-558X .- 0959-4965. ; 6:5, s. 769-772
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Journal article (peer-reviewed)abstract
- Using double-label in situ hybridization, we have explored the possibility that individual CNS neurones can co-express mRNAs for the high-affinity receptors of brain-derived neurotrophic factor and neurotrophin-3, TrkB and TrkC, respectively. The vast majority of TrkC mRNA-containing neurones in the hippocampal formation and cerebral cortex were also labelled for TrkB mRNA. Cells expressing only TrkB or TrkC mRNA were very scarce in these regions, representing < 15% of all labelled cells. These findings suggest that the same cortical or hippocampal neurone can be regulated by several members of the neurotrophin family, which may be important both during development and in response to physiological activity and pathological conditions.
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| 5. |
- Kokaia, Zaal, et al.
(author)
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Regulation of brain-derived neurotrophic factor gene expression after transient middle cerebral artery occlusion with and without brain damage
- 1995
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In: Experimental Neurology. - : Elsevier BV. - 0014-4886. ; 136:1, s. 73-88
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Journal article (peer-reviewed)abstract
- Levels of mRNA for c-fos, nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), TrkB, and TrkC were studied using in situ hybridization in the rat brain at different reperfusion times after unilateral middle cerebral artery occlusion (MCAO). Short-term (15 min) MCAO, which does not cause neuronal death, induced elevated BDNF mRNA expression confined to ipsilateral frontal and cingulate cortices outside the ischemic area. With a longer duration of MCAO (2 h), which leads to cortical infarction, the increase was more marked and elevated BDNF mRNA levels were also detected bilaterally in dentate granule cells and CA1 and CA3 pyramidal neurons. Maximum expression was found after 2 h of reperfusion. At 24 h BDNF mRNA expression had returned to control values. In the ischemic core of the parietal cortex only scattered neurons were expressing high levels of BDNF mRNA after 15 min and 2 h of MCAO. Analysis of different BDNF transcripts showed that MCAO induced a marked increase of exon III mRNA but only small increases of exon I and II mRNAs in cortex and hippocampus. In contrast to BDNF mRNA, elevated expression of c-fos mRNA was observed in the entire ipsilateral cerebral cortex, including the ischemic core, after both 15 min and 2 h of MCAO. Two hours of MCAO also induced transient, bilateral increases of NGF and TrkB mRNA levels and a decrease of NT-3 mRNA expression, confined to dentate granule cells. The upregulation of BDNF mRNA expression in cortical neurons after MCAO is probably triggered by glutamate through a spreading depression-like mechanism. The lack of response of the BDNF gene in the ischemic core may be due to suppression of signal transduction or transcription factor synthesis caused by the ischemia. The observed pattern of gene expression after MCAO agrees well with a neuroprotective role of BDNF in cortical neurons. However, elevated levels of NGF and BDNF protein could also increase synaptic efficacy in the postischemic phase, which may promote epileptogenesis.
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