Differential patterns of dehydroabietic acid biotransformation by Nicotiana tabacum and Catharanthus roseus cells

The aim of this study was to use whole cell catalysts as tools for modification of selected resin acids in order to obtain value-added functional derivatives. The enzymatic bioconversion capacities of two plant species were tested towards dehydroabietic acid. Dehydroabietic acid (DHA) is an abundant resin acid in conifers, representing a natural wood protectant. It is also one of the constituents found in by-products of the kraft chemical pulping industry. DHA was fed to tobacco (Nicotiana tabacum) and Madagascar periwinkle (Catharanthus roseus) plant cell and tissue cultures and bioconversion product formation was monitored using NMR analysis. Both plant species took up DHA from culture medium, and various types of typical detoxification processes occurred in both cultures. In addition, diverse responses to DHA treatment were observed, including differences in uptake kinetics, chemical modification of added substrate and changes in overall metabolism of the cells. Interestingly, Catharanthus roseus, a host species for pharmaceutically valuable terpenoid indole alkaloids, exhibited a very different bioconversion pattern for exogenously applied DHA than tobacco, which does not possess a terpenoid indole pathway. In tobacco, DHA is readily glycosylated in the carbonyl group, whereas in periwinkle it is proposed that a cytochrome P450-catalyzed enzymatic detoxification reaction takes place before the formation of glycosylated product.     

The derivation of clinical-grade human embryonic stem cell lines

The pluripotent nature of human embryonic stem cells (hESC) has attracted great interest in using them as a source of cells or tissue in cell therapy. However, in order to be used in regenerative medicine, the pluripotent hESC lines should be established and propagated according to good manufacturing practice quality requirements. The cultures should be animal substance free in order to exclude the risk of infections and immunogenity. They should also be genetically and epigenetically normal. The detailed molecular mechanisms of their pluripotency are still not defined. Using human feeder cells, a medium containing only human proteins, the mechanical isolation of the inner cell mass and mechanical passaging of hESC, is a safe option until a functional defined medium containing physiological concentrations of regulatory factors is available.     

Association of serum adiponectin concentration to lipid and glucose metabolism in healthy humans.

BACKGROUND: Adiponectin is a recently discovered plasma protein with many associations to glucose and lipid metabolism. Due to its central role in cardiovascular diseases and insulin resistance, we studied the relationship between serum adiponectin and factors reflecting glucose and lipid metabolism. METHODS AND RESULTS: Thirty healthy participants (20M/10F, age 32.0 +/- 2.1 years, BMI 25.8 +/- 0.9 kg/m (2) and HbA (1c) 5.2 +/- 0.1 %) were studied four times at approximately one week intervals. The effects of a 4-hour euglycemic hyperinsulinemia (40 mU/m (2)/min), saline infusion (control), oral glucose, and oral fat load on serum adiponectin were studied. No significant correlation was found between serum adiponectin and insulin sensitivity before (r = 0.25) or after adjustment for age, BMI and gender (r = 0.04). Adiponectin concentration correlated inversely with HbA (1c) (r = - 0.43, p < 0.05), insulin concentration (r = - 0.38, p < 0.05) and triglyceride concentration (r = - 0.42, p < 0.05) but positively with HDL cholesterol (r = 0.38, p < 0.05). Metabolic procedures had no effect on serum adiponectin. CONCLUSIONS: Our findings favor the interpretation that adiponectin is not causally related to insulin sensitivity in healthy participants. The strongest associations of adiponectin in healthy participants are to be found to lipid metabolism. Serum levels of adiponectin are very stable and not acutely affected by hyperinsulinemia, oral glucose or fat load.     

The lysyl hydroxylase isoforms are widely expressed during mouse embryogenesis, but obtain tissue- and cell-specific patterns in the adult

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.     

Spatial and temporal expression pattern of germ layer markers during human embryonic stem cell differentiation in embryoid bodies

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.     

Hypoxic preconditioning advances CXCR4 and CXCR7 expression by activating HIF-1α in MSCs

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.     

Derivation and characterization of three new human embryonic stem cell lines in Finland

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).     

Hormone,vitamin and contaminant status during the moulting/fasting period in ringed seals (Pusa [Phoca] hispida) from Svalbard

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.     

Second cancers following the diagnosis of Merkel cell carcinoma: A nationwide cohort study

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.     

Women With Hypertensive Pregnancies Have Difficulties in Regaining Pre‐pregnancy Weight and Show Metabolic Disturbances

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.