Aquaporins (AQPs) are water channel proteins responsible for water homeostasis and important for proper functioning of all body systems, including reproductive structures. This study was designed to determine their localization and quantitative changes in the pig ovary during different stages of the estrous cycle and early pregnancy. The expression of AQP 1, 5 and 9 proteins was determined by immunocytochemistry and Western blot analyses. AQP1 was found in the plasma membranes of capillary endothelium, AQP5 - in the plasma membranes of granulosa cells of developing follicles and flattened follicle cells of the primordial follicles, and AQP9 - in granulosa cells of the developing follicles. In the cyclic pigs, the expression of AQP1 and 5 proteins was the highest on Days 18-20, but did not change significantly between Days 2-4, 10-12 and 14-16 of the cycle. In pregnant pigs (Days 14-16 and 30-32), the expression of AQP1 and 5 did not change and was similar to that observed during Days 10-12 and 14-16. In turn, AQP9 expression did not change between all studied periods. In conclusion, studied AQP are localized in different cells populations, the endothelial and granulosa cells, and AQP1 and 5 seem to be crucial for follicular development in pigs., A. Skowronska, P. Mlotkowska, M. Eliszewski, S. Nielsen, M. T. Skowronski., and Obsahuje bibliografii
Estrogen replacement therapy could play a role in the reduction of injury associated with cerebral ischemia in vivo, which could be, at least partially, a consequence of estrogen influence of glutamate buffering by astrocytes during hypoxia/ischemia. Estrogen exerts biological effects through interaction with its two receptors: estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ), which are both expressed in astrocytes. This study explored effects of hypoxia and glucose deprivation (HGD), alone or followed by 1 h recovery, on ERα and ERβ expression in primary rat astrocyte cultures following 1 h exposure to: a) 5 % CO2 in air (control group-CG); b) 2 % O2/5 % CO2 in N2 with glucose deprivation (HGD group-HGDG); or c) the HGDG protocol followed by 1 h CG protocol (recovery group-RG). ER α mRNA expression decreased in HGDG. At the protein level, full-length ER α (67 kDa) and three ER α -immunoreactive protein bands (63, 60 and 52 kDa) were detected. A significant decrease in the 52 kDa band was seen in HGDG, wh ile a significant decrease in expression of the full length ERα was seen in the RG. ERβ mRNA and protein expression (a 54 kDa single band) did not change. The observed decrease in ER α protein may limit estrogen-mediated signalling in astrocytes during hypoxia and recovery., M. D. Al-Bader, S. A. Malatiali, Z. B. Redzic., and Obsahuje bibliografii a bibliografické odkazy
Many stress conditions are ac companied by skeletal muscle dysfunction and regeneration, which is essentially a recapitulation of the embryonic development. However, regeneration usually occurs under conditions of hypo thalamus-pituitary -adrenal gland axis activation and therefore incr eased glucocorticoid (GC) levels. Glucocorticoid receptor (GR), the main determinant of cellular responsiveness to GCs, exists in two isoforms (GRα and GRβ ) in humans. While the role of GR α is well characterized, GRβ remains an elusive player in GC si gnalling. To elucidate basic characteristics of GC signalling in the regenerating human skeletal muscle we assessed GRα and GCβ expression pattern in cultured human myoblasts and myotubes and their response to 24-hour dexamethasone (DEX) treatment. There was no difference in GRα mRNA and protein expression or DEX-mediated GRα down-regulation in myoblasts and myotubes. GRβ mRNA level was very low in myoblasts and remained unaffected by differentiation and/or DEX. GRβ protein could not be detected. These results indicate that response to GCs is established very early during human skeletal muscle regeneration and that it remains practically unchanged before innervation is established. Very low GRβ mRNA expression and inability to detect GRβ protein suggests that GRβ is not a major player in the early stages of human skeletal muscle regeneration., D. Filipović ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Hypoxia-inducible factor-1α (HIF-1α) transcriptionally regulates expression of several target genes in protecting tissues against hypoxia. With hypoxic stress, vascular endothelial growth factor (VEGF) is a signal protein produced by cells and further contributes to improvement of vascular functions and restoring the oxygen supply to tissues. In this current study, we first hypothesized that the protein levels of HIF-1α and VEGF are reduced in skeletal muscles of plateau animals [China Qinghai- Tibetan plateau pikas (ochotona curzoniae)] in response to hypoxia as compared with control animals [normal lowland Sprague-Dawley (SD) rats]. We further hypothesized that HIF-1α plays a role in regulating expression of VEGF in skeletal muscle. Note that HIF-1α and VEGF were determined by using two-site immunoenzymatic assay (ELISA) methods. Our results demonstrated that hypoxic stress induced by exposure of lower O2 (6 h) significantly increased the levels of HIF-1α and VEGF in the oxidative and glycolytic muscles of SD rats and pikas (P<0.05 vs. normoxic conditions). Notably, the increases in HIF-1α and VEGF were significantly less in pikas (P<0.05, vs. SD controls) than in SD rats. In addition, a linear relationship was observed between amplified HIF-1α and VEGF in oxidative muscle (r=0.76 and P<0.01) and glycolytic muscle (r=0.72 and P<0.01) and inhibiting HIF-1α significantly decreased expression of VEGF induced by hypoxic stress in skeletal muscles (P<0.05). Overall, our findings suggest that (1) responsiveness of HIF-1α and VEGF in skeletal muscles to hypoxic stress is blunted in plateau animals, and (2) HIF-1α has a regulatory effect on VEGF under hypoxic environment., H.-C. Xie, J.-P. He, J.-F. Zhu, J.-G. Li., and Obsahuje bibliografii
Accumulation of adipose tissue in lower body lowers risk of cardiovascular and metabolic disorders. The molecular basis of this protective effect of gluteofemoral depot is not clear. The aim of this study was to compare the profile of expression of inflammation-related genes in su bcutaneous gluteal (sGAT) and abdominal (sAAT) adipose tissue at baseline and in response to multiphase weight-reducing dietary intervention (DI). 14 premenopausal healthy obese women underwent a 6 months’ DI consisting of 1 month very-low-calorie-diet (VLCD), subsequent 2 months’ low-calori e-diet and 3 months’ weight maintenance diet (WM). Paired samples of sGAT and sAAT were obtained before and at the end of VLCD and WM periods. mRNA expression of 17 genes (macrophage markers, cytokines) was measured using RT-qPCR on chip-platform. At baseline, there were no differences in gene expression of macrophage markers and cytokines between sGAT and sAAT. The dynamic changes induced by DI were similar in both depots for all genes except for three cytokines (IL6, IL10, CCL2) that differed in their response during weight maintenance phase. The results show that, in obese women, there are no major differences between sGAT and sAAT in expression of inflammation-related genes at baseline conditions and in response to the weight-reducing DI., L. Mališová ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
The present studies investigated changes in expression of mRNA for adenosine A1, A2a, A2b, and A3 receptors in samples of HL-60 promyelocytic cells differing in the actual presence of cells in various phases of the cell cycle induced by the double thymidine block method. Real-time PCR technique was used for obtaining data on mRNA expression. Statistical analysis of the data revealed that the mRNA ex pression of adenosine A1, A2a, and A3 receptors is dependent on the cell cycle phase. G0/G1 and G2/M phases were characterized by a higher mRNA expression of adenosine A1 receptors and a lower one of adenosine A2a and A3 receptors whereas the opposite was true for the S phase. Interestingly, expression of mRNA of the adenosine A2b receptors was independent on the cell cycle phase. The results indicate the plasticity of mRNA expression of adenosine receptors in the investigated promyelocytic cells and its interaction with physiological mechanisms of the cell cycle., M. Hofer ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Gastrointestinal form is the second stage of acute radiation syndrome (ARS) with a threshold dose of 8 Gy in man. It represents an absolutely lethal clinical-pathological unit, necro-hemorrhagic enteritis and proctocolitis, with unknown causal therapy. Elk-1 is a protein acting as a transcription factor activating specified genes. The purpose of our study was to examine the expression of phospho-Elk-1 in irradiated jejunum and transversal colon of rats with radiation-induced enterocolitis and to assess the importance of this transcriptional factor as a biodosimetric marker of radiation-induced enteropathy. The laboratory rats were randomly divided into 21 groups, 10 animals per group, and irradiated with whole body γ-irradiation of 1, 5, 10, 15, and 20 Gy. Samples of jejunum and transversal colon were taken 24, 48, 72, and 96 hours later, immunohisto-chemically stained, and the phospho-Elk-1 expression was examined using computer image analysis. A group of 10 sham-irradiated animals was used as control. Significantly increased expression of phospho-Elk-1 in rat jejunum has been found in all time intervals after irradiation by sublethal doses of 1 and 5 Gy, whereas after the irradiation by lethal doses, the expression of phospho-Elk-1 in rat jejunum varied considerably. Significantly increased expression of phospho-Elk-1 in transversal colon has also been found in the first days after irradiation by sublethal doses of 1 and 5 Gy. After irradiation by lethal doses, tere was no uniform pattern of the changes in the expression of phospho-Elk-1 in rat transversal colon. The detection of phospho-Elk-1 might be considered as a suitable and very sensitive biodosimetric marker of radiation-induced injury of small and large intestine. According to our knowledge, this is the first study on the phospho-Elk-1 expression in irradiated jejunum and transversal colon in the rat., D. Driák, J. Österreicher, Z. Řeháková, Z. Vilasová, J. Vávrová., and Obsahuje bibliografii a bibliografické odkazy
Serotonin receptors have been found in several reproductive organs as well as in the central nervous system. Serotonin-binding sites have been demonstrated in duck ovarian follicles and the testis, hamster ovaries, human granulosa cells and mouse placenta. Local production of serotonin by the rat ovary, oviduct, uterus and testis has also been reported. We analyzed the expression of three types of serotonin receptors: 5-HT1B, 5-HT2C and 5-HT1D by reverse transcription-polymerase chain reaction in mouse unfertilized oocytes and preimplantation embryos from zygotes to the blastocyst stage in vivo. Transcripts for 5-HT1B and 5-HT2C serotonin receptors were detected neither in unfertilized oocytes nor at any stages of in vivo developing preimplantation embryos. Serotonin 5-HT1D receptor mRNA was present in unfertilized oocytes, zygotes, 2-cell embryos, compacted morulae and in vivo produced expanded blatocysts. The expression of the mRNA 5-HT1D serotonin receptor was also detected in blastocysts cultured in vitro. When added to the culture medium, specific serotonin 5-HT1D agonist sumatriptan (1 μM) significantly inhibited the development of mouse embryos cultured in vitro. Demonstration of the expression of 5-HT1D serotonin receptor in mouse oocytes and preimplantation embryos supports the idea of a functional serotonin (5-HT1D) receptor in early mammalian development., J. Veselá, P. Rehák, J. Mihalik, S. Czikková, J. Pokorný, J. Koppel., and Obsahuje bibliografii
a1_We have investigated expression of skeletal calsequestrin (CSQ1) and fiber type composition in normal and regenerated fast and slow skeletal muscles and in the left heart ventricles of euthyroid (EU), hypothyroid (HY) and hyperthyroid (TH) adult inbred Lewis strain rats. The CSQ1 level was determined by SDS-PAGE followed by Western blot analysis. CSQ1 gene expression was assessed using reverse transcription and subsequent real time polymerase chain reaction. Muscle regeneration was achieved by intramuscular grafting of either soleus or extensor digitorum longus (EDL) from 3- to 4-week-old rats to either EDL or soleus muscle of 2-month-old rats. The fiber type composition was assessed by a stereological method applied to stained muscle cross sections. We found that the protein and mRNA levels for CSQ1 were highest in the EDL muscle, the relative CSQ1 protein levels in the soleus muscle were two times lower and the transcript levels more than 5 times lower compared to the EDL. In the left heart ventricle, protein isoform and CSQ1 transcript were also present, although at protein level, CSQ1 was hardly detectable. TH status increased and HY status decreased the expression of CSQ1 in the EDL, but its relative levels in the soleus and in the heart did not change. The regenerated soleus transplanted into EDL, as well as EDL transplanted into soleus exhibited protein and mRNA levels of CSQ1 corresponding to the host muscle and not to the graft source. TH status increased the percentages of the fastest 2X/D and 2B fibers at the expense of slow type 1 and fast 2A fibers in the EDL and that of fast 2A fibers in the soleus at the expense of slow type 1 fibers. HY status led to converse fiber type changes., a2_We suggest that the observed changes in CSQ1 levels in TH and HY compared to EU rats can be related to fiber type changes caused by alteration of the thyroid status rather than to the direct effect of thyroid hormones on CSQ1 gene expression., T. Soukup ... [et al.]., and Obsahuje seznam literatury