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71.
Antti M. Salo Laura Sipil Raija Sormunen Heli Ruotsalainen Seppo Vainio Raili Myllyl 《Matrix biology》2006,25(8):475-483
Lysyl hydroxylase catalyzes the hydroxylation of lysine residues in collagenous sequences. Three isoforms (LH1, LH2 and LH3) of lysyl hydroxylase have been characterized, and LH2 is present as two alternatively spliced forms. In order to better understand the functional differences between the isoforms in vivo, the expression of the different isoforms was studied in mouse embryos and adult tissues. Our data indicate a widespread expression of all isoforms during embryogenesis, whereas the expression profiles become more specialized in adult tissues. The expression of LH2 was more tissue-specific, whereas a uniform and housekeeping like behavior was observed for LH3. Some cells express both LH2 and LH3, while a clear cell specificity was seen in some tissues. Moreover, immunoelectron microscopy revealed differences in the localization of LH2 and LH3. LH2 was localized intracellularly in the ER in all tissues studied, whereas the localization of LH3 was either intracellular or extracellular or both, depending on the tissue. Furthermore, our data indicate that the alternative splicing of LH2 is developmentally regulated. The short form of LH2 (LH2a) is the predominant form until E11.5; the long form (LH2b) dominates thereafter and is the major form in many adult tissues. Interestingly, however, adult mouse kidney and testis express exclusively the short form, LH2a. The results reveal a specific regulation for the expression of LH isoforms as well as for alternative splicing of LH2 during embryogenesis and in different tissues. 相似文献
72.
73.
Mari Pekkanen-Mattila Markku Pelto-Huikko Ville Kujala Riitta Suuronen Heli Skottman Katriina Aalto-Setälä Erja Kerkelä 《Histochemistry and cell biology》2010,133(5):595-606
Human embryonic stem cell (hESC) differentiation in embryoid bodies (EBs) provides a valuable tool to study the interplay
of different germ layers and their influence on cell differentiation. The gene expression of the developing EBs has been shown
in many studies, but the protein expression and the spatial composition of different germ layers in human EBs have not been
systematically studied. The aim of the present work was to study the temporal and spatial organisation of germ layers based
on the expression of mesoderm (Brachyury T), endoderm (AFP) and ectoderm (SOX1) markers during the early stages of differentiation
in eight hESC lines. Tissue multi-array technology was applied to study the protein expression of a large number of EBs. According
to our results, EB formation and the organisation of germ layers occurred in a similar manner in all the lines. During 12 days
of differentiation, all the germ layer markers were present, but no obvious distinct trajectories were formed. However, older
EBs were highly organised in structure. Pluripotency marker OCT3/4 expression persisted unexpectedly long in the differentiating
EBs. Cavity formation was observed in the immunocytological sections, and caspase-3 expression was high, suggesting a role
of apoptosis in hESC differentiation and/or EB formation. The expression of Brachyury T was notably low in all the lines,
also those with the best cardiac differentiation capacity, while the expression of SOX1 was higher in some lines, suggesting
that the neural differentiation propensity may be detectable already in the early stages of EB differentiation. 相似文献
74.
Hongbao Liu Guanqun Ge Xiaohui Luo Yang Li Heli Xiang Xiaoming Ding Puxun Tian Xiaohui Tian 《Biochemical and biophysical research communications》2010,401(4):509-515
Recent evidence indicated that sublethal hypoxic preconditioning (HP) of bone marrow-derived mesenchymal stem cells (MSCs) before transplantation could ameliorate their capacity to survive and engraft in the target tissue through yet undefined mechanisms. In this study, we demonstrated that HP (3% oxygen) induced the high expression of both chemokine stromal-derived factor-1 (SDF-1) receptors, CXCR4 and CXCR7, in MSCs. HP also improved in vitro migration, adhesion and survival of MSCs. Although SDF-1-induced migration of HP-MSCs was only abolished by an anti-CXCR4 antibody, both CXCR4 and CXCR7 were responsible for elevated adhesion of HP-MSCs. Moreover, CXCR7 but not CXCR4 was essential for the resistance to oxidative stress of HP-MSC. In addition, HP also evoked an increase in expression of hypoxia-inducible factor-1 (HIF-1α) and phosphorylation of Akt. The chemical inducers of HIF-1α, desferrioxamine (DFX) and cobalt chloride (CoCl2), induced upregulation of CXCR4 and CXCR7 expression in MSCs under normoxic conditions. Contrarily, blockade of HIF-1α by siRNA and inhibition of Akt by either wortmannin or LY294002 abrogated upregulation of HP-induced CXCR4 and CXCR7 in MSCs. Collectively, these findings provide evidence for a crucial role of PI3K/Akt-HIF-1α-CXCR4/CXCR7 pathway on enhanced migration, adhesion and survival of HP-MSCs in vitro. 相似文献
75.
Heli Skottman 《In vitro cellular & developmental biology. Animal》2010,46(3-4):206-209
Human embryonic stem cell (hESC) lines can be established from the preimplantation embryos. Due to their ability to differentiate into all three embryonic layers, hESC are of significant interest as a renewable source of cell material for different applications, especially for cell replacement therapy. Since the establishment of the first hESC lines in 1998, several studies have described the derivation and culture of new hESC lines using various derivation methods and culture conditions. Our group has currently established eight new hESC lines of which three of the latest ones are described in a more detailed way in this report. The described lines have been established using mechanical derivation methods for surplus bad quality embryos and culture conditions containing human foreskin fibroblast feeder cells and serum-free culture medium. All the new lines have a normal karyotype and typical hESC characteristics analyzed in vitro. The described hESC lines are available for research purposes upon request (www.regea.fi). 相似文献
76.
Heli Routti Bjørn Munro Jenssen Christian Lydersen Christina Bäckman Augustine Arukwe Madeleine Nyman Kit M. Kovacs Geir Wing Gabrielsen 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2010,155(1):70-76
This study investigates the potential effects of moulting, and the concomitant period of fasting undertaken by ringed seals, on hormone, vitamin and contaminant status in adult animals in a population from Svalbard, Norway, which has relatively low contaminant levels. Concentrations of circulating total and free thyroxine and triiodothyronine, circulating and hepatic vitamin A, hepatic persistent organic pollutants and their circulating hydroxyl metabolites were higher in moulting seals compared to pre-moulting seals. The opposite trend was observed for body condition, circulating calcitriol levels and hepatic mRNA expression of thyroid hormone receptor β. No differences were observed for circulating or hepatic vitamin E levels or hepatic mRNA expressions for deioidinase 1 or 2, or retinoic acid receptor α between the two seal groups. The observed differences are likely the result of increased metabolic rates required during moulting to maintain thermal balance and replace the pelage, in combination with mobilization of lipid soluble compounds from blubber stores during the fasting period that is associated with moulting. The present study shows that contaminant levels and their relationships with physiological or endogenous variables can be highly confounded by moulting/fasting status. Thus, moulting status and body condition should be taken into consideration when using variables related to thyroid, calcium or vitamin A homeostasis as biomarkers for contaminant effects. 相似文献
77.
Virve Koljonen Heli Kukko Erkki Tukiainen Tom Böhling Risto Sankila Heikki Joensuu Eero Pukkala 《Cancer epidemiology》2010,34(1):62-65
Merkel cell carcinoma (MCC) is a rare neuroendocrine carcinoma of the skin. MCCs and some other skin cancers, such as basal cell carcinomas, frequently harbour Merkel cell polyomavirus DNA. The purpose of the study was to investigate the frequency of second cancers following the diagnosis of MCC. We studied the incidence of second primary cancers after the diagnosis of MCC from the files of the Finnish Cancer Registry in 1979–2006. Among the 172 MCC patients identified a total of 34 second primary cancers were detected in 30 individuals after the diagnosis of MCC. Female MCC patients were diagnosed with 25 subsequent cancers (SIR, 2.35; 95% CI, 1.52–3.47; p < 0.001) and male patients with 9 cancers (SIR, 2.32, 95% CI, 1.06–4.40; p < 0.05). The MCC patients had an increased risk for a subsequent cancer (any site) compared to age-, gender- and calendar period-matched general population (standardized incidence ratio [SIR] 2.34; 95% confidence interval [CI], 1.62–3.27). The risks for basal cell carcinoma of the skin (O = 11), SIR, 3.48; 95% CI, 1.74–6.22 and chronic lymphocytic leukemia (O = 2), SIR, 17.9; 95% CI, 2.16–64.6 were significantly elevated. The SIRs for an overall second primary cancer risk did not change markedly with time since the diagnosis of MCC. We conclude that patients diagnosed with MCC have an increased risk for a second cancer. This risk may in part result from shared etiological factors between MCC and other tumour types, such as immunosuppression or possibly Merkel cell polyomavirus infection. 相似文献
78.
Katariina Suntio Heli Saarelainen Tomi Laitinen Pirjo Valtonen Nonna Heiskanen Tiina Lyyra‐Laitinen Esko Vanninen Seppo Heinonen 《Obesity (Silver Spring, Md.)》2010,18(2):282-286
The aim was to determine maternal weight gain and body composition during pregnancy and 3 months postpartum in women with uncomplicated singleton and twin pregnancies and in women with gestational diabetes (GDM) and gestational hypertension (GH). This prospective study includes four groups of subjects: those with an uncomplicated pregnancy (n = 32), those with a diagnosis of GH (n = 28), those with a diagnosis of GDM (n = 52), and those with twin pregnancy (n = 11). Their body compositions were estimated by a bioimpedance analysis and fasting lipids and glucose levels were determined during the pregnancy and 3 months after pregnancy. Women with GDM were 11.7 kg heavier than the reference group before pregnancy, whereas weight before pregnancy was not different in other investigated groups. Weight loss after delivery was attenuated in GH group. Percentage body fat remained elevated in women with GDM (34.1 ± 7.0%) and hypertension (31.5 ± 6.4%) at 3 months after pregnancy. Also their total cholesterol and low‐density lipoprotein (LDL)‐cholesterol levels as well as fasting glucose remained elevated in comparison to values of the reference group. In conclusion, women with hypertensive pregnancies, though not overweight before pregnancy, gain and retain excess gestational weight and this leads to metabolic abnormalities similar to those seen in women GDM. Thus, postpartum period appears to be critical for weight management and interventional programs are called for. 相似文献
79.
Sirén H Karttunen A 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2003,783(1):113-124
This study presents the optimization of a microemulsion electrokinetic chromatographic (MEEKC) electrolyte solution by using UV detection and with the method, simultaneous separations of chemically, biochemically and pharmaceutically related anionic and cationic compounds. Representatives of the compound groups were from isoflavonoids, benzodiazepines, metanephrines, diuretics and peptide hormones. The MEEKC separations under basic conditions were first optimized using a two-component isoflavonoid mixture as the sample and an electrolyte containing 10 mM tetraborate as the main buffer (pH 9.5). The stable microemulsion phase was adjusted with various amounts of octane, 1-butanol and sodium dodecyl sulfate (SDS). An only acidified electrolyte solution used in the study was made of phosphoric acid (pH 1.8) containing octane, SDS and ethyl acetate. The analyses with isoflavonoids showed that electrophoretic mobilities of the investigated compounds were highly related to the concentrations of SDS and 1-butanol with linear and parabolic correlation, respectively. However, addition of octane gave linear correlation only at low concentrations. In most cases four to six structurally related compounds and even 13 diuretics with various polar properties were separated from each other in basic microemulsion medium. The acidified MEEKC electrolyte gave good resolution for anionic metanephrines. 相似文献
80.
Shengjuan Hu Yan Zhou Yanhong Deng Yang Bo Xianmei Chen Wei Yang Ruichun Shi Wei Zhao Zhanbing Hou Jianping Hu Jianguo Liu Xilong Zhang Heli Yong Ping Wang Fei Li Hailong Qi Xiaoyun Wang Lijuan Jin Ting Cui Haijiang Yong Xue Li Bin Yang Yuehua Yu Bin Ma Lei Fu Xuemei Wang Zhen Ma Na Tang Yanjie You Jianyang Guo Xiaobing Yu Li Yao Ruiping Gao Yanling Li Ruijuan Xin Jianfang Liu Zhenzi Cao Hongliang Li Linke Ma Shoucheng Ma Ying Cao Yuanyuan Tang Jun Liu Qian Hao Xiaofei Li Xuemei Li Rui Mu Min Niu Xiaoming Su Hengjun Gao 《Helicobacter》2023,28(3):e12960