Development and validation of a gene expression test to identify hard-to-heal chronic venous leg ulcers.

BACKGROUND: Chronic venous leg ulcers pose a significant burden to healthcare systems, and predicting wound healing is challenging. The aim of this study was to develop a genetic test to evaluate the propensity of a chronic ulcer to heal. METHODS: Sequential refinement and testing of a gene expression signature was conducted using three distinct cohorts of human wound tissue. The expression of candidate genes was screened using a cohort of acute and chronic wound tissue and normal skin with quantitative transcript analysis. Genes showing significant expression differences were combined and examined, using receiver operating characteristic (ROC) curve analysis, in a controlled prospective study of patients with venous leg ulcers. A refined gene signature was evaluated using a prospective, blinded study of consecutive patients with venous ulcers. RESULTS: The initial gene signature, comprising 25 genes, could identify the outcome (healing versus non-healing) of chronic venous leg ulcers (area under the curve (AUC) 0·84, 95 per cent c.i. 0·73 to 0·94). Subsequent refinement resulted in a final 14-gene signature (WD14), which performed equally well (AUC 0·88, 0·80 to 0·97). When examined in a prospective blinded study, the WD14 signature could also identify wounds likely to demonstrate signs of healing (AUC 0·73, 0·62 to 0·84). CONCLUSION: A gene signature can identify people with chronic venous leg ulcers that are unlikely to heal.

Effects of sporidesmin on cultured biliary tract cells from Romney lambs that differed in their sensitivity to sporidesmin.

AIMS To investigate the effects of sporidesmin on cells cultured from the epithelial surface of sheep gallbladder walls, and to examine cellular responses to sporidesmin using cultures prepared from the gallbladders of sheep from selection lines that differed in sensitivity to sporidesmin-induced liver damage. METHODS Gallbladders were obtained following slaughter of lambs that were selected for resistance or susceptibility to sporidesmin-induced liver damage, or were not selected (controls). Monolayer cell cultures were established after incubation of excised gallbladders with protease to detach the lining epithelial cells from the muscular and connective tissue of the gallbladder wall. Released cells were harvested and transferred to culture flasks or dishes, then incubated with 1 µg/mL sporidesmin and were examined at 5 minute intervals, up to 3 hours, using light microscopy to monitor loss of attachment of cultured cells. Immunofluorescence staining of cell cultures was used to identify cytokeratin 19 as a marker for biliary epithelial cells, and to characterise sporidesmin-induced change in the cellular distribution of actin microfilaments. Gallbladder size was also measured. RESULTS In cultures incubated with sporidesmin, cells at the margins of sheets of cells showed the first signs of change, becoming unanchored from the culture vessels while remaining attached to the cell mass. This was followed by progressive detachment of sheets of cells and clumps of rounded cells. Disruption of cytoplasmic actin microfilaments with accumulation of actin in the cytoplasm adjacent to the plasma membrane preceded major detachment of cells. Cells from susceptible line lambs were extensively rounded up within 1 hour with complete or almost complete detachment within 2 hours, whereas cultures from resistant line lambs generally only contained detaching rounded-up cells at the periphery of monolayers within 2 hours; detachment observed in cells from the control line lambs was intermediate. There was a trend for gallbladders to be smaller in male lambs from the resistant line compared to the control or susceptible lines. CONCLUSIONS Altered cell adhesion and disruption of microfilament actin in biliary cell cultures incubated with sporidesmin suggest that biliary tract pathology may be due to the effects of the toxin on cytoplasmic and cell surface protein networks that affect the integrity of the epithelial lining of the biliary tract. These effects can be interpreted in terms of the hepatobiliary pathology of facial eczema, including potential differences in sensitivity of biliary tract cells that may contribute to inherited resistance and susceptibility to sporidesmin and hence facial eczema.

Animal physiology and genetic aspects of ryegrass staggers in grazing sheep.

Ryegrass staggers (RGS) is a metabolic disease of herbivores, caused by the ingestion of perennial ryegrass (Lolium perenne L.) containing a fungal endophyte (Neotyphodium lolii) which produces a tremorgenic toxin, lolitrem B. RGS has a major economic impact for agriculture in New Zealand as well as internationally. Management of RGS in grazing sheep can be problematic, and there is an incomplete knowledge of the interaction between the toxin and the grazing animal. This review is focused on recent advances in understanding the molecular physiology of RGS in the affected animal as well as the influence of animal genetics on the degree of susceptibility to RGS. Investigations to date suggest that the primary target for toxin is the large conductance, calcium-activated, potassium (BK) channel, resulting in disruption of neuromuscular junction signalling. Genetic investigation has established the existence of genes influencing resistance to RGS, however their identity has not been confirmed and their impact has not been established. Studies to date suggest that a multi-gene selection approach will be necessary in order to develop an effective selection tool for use in the agricultural industries.

Intracellular localization and induction of a dynamic RNA-editing event of macro-algal V-ATPase subunit A (VHA-A) in response to copper.

A V-ATPase subunit A protein (VHA-A) transcript together with a variant (C793 to U), which introduces a stop codon truncating the subunit immediately downstream of its ATP binding site, was identified within a Fucus vesiculosus cDNA from a heavy metal contaminated site. This is intriguing because the VHA-A subunit is the crucial catalytic subunit responsible for the hydrolysis of ATP that drives ion transport underlying heavy metal detoxification pathways. We employed a chemiluminescent hybridization protection assay to quantify the proportion of both variants directly from mRNA while performing quantification of total transcript using Q-PCR. Polyclonal antisera raised against recombinant VHA-A facilitated simultaneous detection of parent and truncated VHA-A and revealed its cellular and subcellular localization. By exploiting laboratory exposures and samples from an environmental copper gradient, we showed that total VHA-A transcript and protein, together with levels of the truncated variant, were induced by copper. The absence of a genomic sequence representing the truncated variant suggests a RNA editing event causing the production of the truncated VHA-A. Based on these observations, we propose RNA editing as a novel molecular process underpinning VHA trafficking and intracellular sequestration of heavy metals under stress.

Effects of quantitative trait loci and the myostatin locus on trace and macro elements (minerals) in bovine liver, muscle and kidney.

A quantitative trait locus (QTL) study of the concentrations of 14 trace and macro elements (minerals) in tissues of beef cattle was conducted in New Zealand. Back-cross calves with Jersey and Limousin ancestry (202 heifers and 211 steers) were generated using first-cross sires. This paper reports on testing for effects of QTL on the concentrations of minerals in liver, kidney and muscle in cattle at slaughter, following a growth phase during which rearing and finishing stages were on pasture. Fifteen QTL were identified (P < 0.05) on a genome-wide basis in combined-sire and within-sire analyses. In addition, the possible effect of the Limousin myostatin F94L allele was tested by fitting each calf's myostatin genotype, and 16 QTL were identified. Twelve were in common with those QTL identified previously, comprising six affecting the liver (copper and zinc, on two chromosomes each; plus iron and molybdenum), three affecting the kidney (calcium, copper and iron), and three affecting muscle (iron, strontium and zinc).

Hemizygosity at the elastin locus in a developmental disorder, Williams syndrome.

Williams syndrome (WS) is a developmental disorder affecting connective tissue and the central nervous system. A common feature of WS, supravalvular aortic stenosis, is also a distinct autosomal dominant disorder caused by mutations in the elastin gene. In this study, we identified hemizygosity at the elastin locus using genetic analyses in four familial and five sporadic cases of WS. Fluorescent in situ hybridization and quantitative Southern analyses confirmed these findings, demonstrating inherited and de novo deletions of the elastin gene. These data indicate that deletions involving one elastin allele cause WS and implicate elastin hemizygosity in the pathogenesis of the disease.

A gene for Crouzon craniofacial dysostosis maps to the long arm of chromosome 10.

Crouzon craniofacial dysostosis (CFD) is an autosomal dominant craniofacial disorder characterized by premature craniosynostosis, shallow orbits and hypoplastic maxilla. To map the gene responsible, we have used a mapping strategy of testing for linkage to known developmental genes. Analysis of a large kindred established linkage between CFD and three loci (D10S190, D10S209 and D10S216) that span a 13 cM region on chromosome 10q. A maximum pairwise lod score of 4.42 (theta = 0) at D10S190 was obtained and the addition of a second kindred produced a combined pairwise lod score of 5.32 (theta = 0) at the same locus. The developmental gene, PAX2, located within this region, is an attractive candidate gene.

Prolonged voluntary wheel running reveals unique adaptations in mdx mice treated with microdystrophin constructs ± the nNOS-binding site.

We tested the effects of prolonged voluntary wheel running on the muscle function of mdx mice treated with one of two different microdystrophin constructs. At 7 weeks of age mdx mice were injected with a single dose of AAV9-CK8-microdystrophin with (gene therapy 1, GT1) or without (gene therapy 2, GT2) the nNOS-binding domain and were assigned to one of four gene therapy treated groups: mdxRGT1 (run, GT1), mdxGT1 (no run, GT1), or mdxRGT2 (run,GT2), mdxGT2 (no run, GT2). There were two mdx untreated groups injected with excipient: mdxR (run, no gene therapy) and mdx (no run, no gene therapy). A third no treatment group, Wildtype (WT) received no injection and did not run. mdxRGT1, mdxRGT2 and mdxR performed voluntary wheel running for 52 weeks; WT and remaining mdx groups were cage active. Robust expression of microdystrophin occurred in diaphragm, quadriceps, and heart muscles of all treated mice. Dystrophic muscle pathology was high in diaphragms of non-treated mdx and mdxR mice and improved in all treated groups. Endurance capacity was rescued by both voluntary wheel running and gene therapy alone, but their combination was most beneficial. All treated groups increased in vivo plantarflexor torque over both mdx and mdxR mice. mdx and mdxR mice displayed ∼3-fold lower diaphragm force and power compared to WT values. Treated groups demonstrated partial improvements in diaphragm force and power, with mdxRGT2 mice experiencing the greatest improvement at ∼60% of WT values. Evaluation of oxidative red quadriceps fibers revealed the greatest improvements in mitochondrial respiration in mdxRGT1 mice, reaching WT levels. Interestingly, mdxGT2 mice displayed diaphragm mitochondrial respiration values similar to WT but mdxRGT2 animals showed relative decreases compared to the no run group. Collectively, these data demonstrate that either microdystrophin construct combined with voluntary wheel running increased in vivo maximal muscle strength, power, and endurance. However, these data also highlighted important differences between the two microdystrophin constructs. GT1, with the nNOS-binding site, improved more markers of exercise-driven adaptations in metabolic enzyme activity of limb muscles, while GT2, without the nNOS-binding site, demonstrated greater protection of diaphragm strength after chronic voluntary endurance exercise but decreased mitochondrial respiration in the context of running.

Genetic mapping of quantitative trait loci for meat quality and muscle metabolic traits in cattle.

A whole-genome scan was carried out in New Zealand and Australia to detect quantitative trait loci (QTL) for live animal and carcass composition traits and meat quality attributes in cattle. Backcross calves (385 heifers and 398 steers) were generated, with Jersey and Limousin backgrounds. The New Zealand cattle were reared and finished on pasture, whilst Australian cattle were reared on grass and finished on grain for at least 180 days. This paper reports on meat quality traits (tenderness measured as shear force at 4-5 ages on two muscles as well as associated traits of meat colour, pH and cooking loss) and a number of metabolic traits. For meat quality traits, 18 significant QTL (P < 0.05), located in nine linkage groups, were detected on a genome-wise basis, in combined-sire (seven QTL) or within-sire analyses (11 QTL). For metabolic traits, 11 significant QTL (P < 0.05), located in eight linkage groups, were detected on a genome-wise basis, in combined-sire (five QTL) or within-sire analyses (six QTL). BTA2 and BTA3 had QTL for both metabolic traits and meat quality traits. Six significant QTL for meat quality and metabolic traits were found at the proximal end of chromosome 2. BTA2 and BTA29 were the most common chromosomes harbouring QTL for meat quality traits; QTL for improved tenderness were associated with Limousin-derived and Jersey-derived alleles on these two chromosomes, respectively.

Genetic variation in the beta, beta-carotene-9', 10'-dioxygenase gene and association with fat colour in bovine adipose tissue and milk.

beta, beta-carotene-9', 10'-dioxygenase (BCO2) plays a role in cleaving beta-carotene eccentrically, and may be involved in the control of adipose and milk colour in cattle. The bovine BCO2 gene was sequenced as a potential candidate gene for a beef fat colour QTL on chromosome (BTA) 15. A single nucleotide base change located in exon 3 causes the substitution of a stop codon (encoded by the A allele) for tryptophan(80) (encoded by the G allele) (c. 240G>A, p.Trp80stop, referred to herein as SNP W80X). Association analysis showed significant differences in subcutaneous fat colour and beta-carotene concentration amongst cattle with different BCO2 genotypes. Animals with the BCO2 AA genotype had more yellow beef fat and a higher beta-carotene concentration in adipose tissues than those with the GA or GG genotype. QTL mapping analysis with the BCO2 SNP W80X fitted as a fixed effect confirmed that this SNP is likely to represent the quantitative trait nucleotide (QTN) for the fat colour-related traits on BTA 15. Moreover, animals with the AA genotype had yellower milk colour and a higher concentration of beta-carotene in the milk.

Quantitative trait loci for organ weights and adipose fat composition in Jersey and Limousin back-cross cattle finished on pasture or feedlot.

A QTL study of live animal and carcass traits in beef cattle was carried out in New Zealand and Australia. Back-cross calves (385 heifers and 398 steers) were generated, with Jersey and Limousin backgrounds. This paper reports on weights of eight organs (heart, liver, lungs, kidneys, spleen, gastro-intestinal tract, fat, and rumen contents) and 12 fat composition traits (fatty acid (FA) percentages, saturated and monounsaturated FA subtotals, and fat melting point). The New Zealand cattle were reared and finished on pasture, whilst Australian cattle were reared on grass and finished on grain for at least 180 days. For organ weights and fat composition traits, 10 and 12 significant QTL locations (P<0.05), respectively, were detected on a genome-wide basis, in combined-sire or within-sire analyses. Seven QTL significant for organ weights were found at the proximal end of chromosome 2. This chromosome carries a variant myostatin allele (F94L), segregating from the Limousin ancestry, and this is a positional candidate for the QTL. Ten significant QTL for fat composition were found on chromosomes 19 and 26. Fatty acid synthase and stearoyl-CoA desaturase (SCD1), respectively, are positional candidate genes for these QTL. Two FA QTL found to be common to sire groups in both populations were for percentages of C14:0 and C14:1 (relative to all FAs) on chromosome 26, near the SCD1 candidate gene.

A genome-screen experiment to detect quantitative trait loci affecting resistance to facial eczema disease in sheep.

Facial eczema (FE) is a secondary photosensitization disease arising from liver cirrhosis caused by the mycotoxin sporidesmin. The disease affects sheep, cattle, deer and goats, and costs the New Zealand sheep industry alone an estimated NZ$63M annually. A long-term sustainable solution to this century-old FE problem is to breed for disease-resistant animals by marker-assisted selection. As a step towards finding a diagnostic DNA test for FE sensitivity, we have conducted a genome-scan experiment to screen for quantitative trait loci (QTL) affecting this trait in Romney sheep. Four F(1) sires, obtained from reciprocal matings of FE resistant and susceptible selection-line animals, were used to generate four outcross families. The resulting half-sib progeny were artificially challenged with sporidesmin to phenotype their FE traits measured in terms of their serum levels of liver-specific enzymes, namely gamma-glutamyl transferase and glutamate dehydrogenase. In a primary screen using selective genotyping on extreme progeny of each family, a total of 244 DNA markers uniformly distributed over all 26 ovine autosomes (with an autosomal genome coverage of 79-91%) were tested for linkage to the FE traits. Data were analysed using Haley-Knott regression. The primary screen detected one significant and one suggestive QTL on chromosomes 3 and 8 respectively. Both the significant and suggestive QTL were followed up in a secondary screen where all progeny were genotyped and analysed; the QTL on chromosome 3 was significant in this analysis.

Quantitative trait loci for live animal and carcass composition traits in Jersey and Limousin back-cross cattle finished on pasture or feedlot.

A quantitative trait locus (QTL) study was carried out in two countries, recording live animal and carcass composition traits. Back-cross calves (385 heifers and 398 steers) were generated, with Jersey and Limousin breed backgrounds. The New Zealand cattle were reared on pasture to carcass weights averaging 229 kg, whilst the Australian cattle were reared on grass and finished on grain (for at least 180 days) to carcass weights averaging 335 kg. From 11 live animal traits and 31 carcass composition traits respectively, 5 and 22 QTL were detected in combined-sire analyses, which were significant (P < 0.05) on a genome-wise basis. Fourteen significant traits for carcass composition QTL were on chromosome 2 and these were traits associated with muscling and fatness. This chromosome carried a variant myostatin allele (F94L), segregating from the Limousin ancestry. Despite very different cattle management systems between the two countries, the two populations had a large number of QTL in common. Of the 18 traits which were common to both countries, and which had significant QTL at the genome-wise level, eight were significant in both countries.

Variation in bull beef quality due to ultimate muscle pH is correlated to endopeptidase and small heat shock protein levels.

This study set out to determine if ultimate pH (pH(u)) affected the performance of intracellular small heat shock protein and endopeptidase dynamics in muscle during beef ageing. Longissimus dorsi muscles from 39 Angus or Limousin×Angus bulls were examined to see if pH(u) achieved at 22h post mortem (rigor) affected tenderness and water holding capacity of beef. Samples were segregated into three pH(u) groups termed high (pH>6.3), intermediate (5.73 days post mortem for intermediate pH(u) beef. High levels of alpha ß-crystallin (aßC) at 22h post mortem coincided with delayed muscle protein degradation for low pH(u) beef. Our results support the hypothesis that aßC shields myofibrils and buffers against endopeptidase degradation of beef structure during ageing.

Marinobufagenin inhibits proliferation and migration of cytotrophoblast and CHO cells.

Marinobufagenin (MBG) is an endogenous mammalian cardiotonic steroid that is involved in the inhibition of the sodium pump Na(+)/K(+)-ATPase. Increased plasma levels of MBG have been reported in patients with volume expansion-mediated hypertension and preeclampsia. We have recently demonstrated that MBG impairs both the proliferation and growth factor-induced migration of human first trimester cytotrophoblast (CTB) cells, crucial for proper placental development. However, the intracellular signaling mechanisms regulating the MBG-induced impairment of CTB differentiation, migration and invasion are unknown. The human extravillous CTB cell line SGHPL-4 was utilized for this study. The phosphorylation of MAP kinase protein ERK1/2 was evaluated by Cellular Activation of Signaling ELISA (CASE) in control CTB cells and those treated with MBG. MBG at concentrations of 10 and 100nM inhibited CTB cell proliferation, migration and invasion (60%, 50% and 50%, respectively). MBG also caused a significant decrease in the phosphorylation of ERK1/2. In addition, MBG decreased proliferation, migration, and ERK1/2 activity in another motile cell line, CHO cells. Another sodium pump inhibitor, ouabain, similarly decreased proliferation and ERK1/2 activity in CTB and CHO cells. These data suggest that the changes observed in cell function may be mediated by inhibition of Na(+)/K(+)-ATPase. We demonstrate that the MBG-induced impairment of CTB cell proliferation, migration and invasion is associated with decreased ERK1/2 activity which may be mediated by inhibition of Na(+)/K(+)-ATPase.

Supravalvular aortic stenosis associated with a deletion disrupting the elastin gene.

Supravalvular aortic stenosis (SVAS) is an inherited vascular disease that can cause heart failure and death. SVAS can be inherited as an autosomal dominant trait or as part of a developmental disorder, Williams syndrome (WS). In recent studies we presented evidence suggesting that a translocation disrupting the elastin gene caused SVAS in one family while deletions involving the entire elastin locus caused WS. In this study, pulsed-field, PCR, and Southern analyses showed that a 100-kb deletion of the 3' end of the elastin gene cosegregated with the disease in another SVAS family. DNA sequence analysis localized the breakpoint between elastin exons 27 and 28, the same region disrupted by the SVAS-associated translocation. These data indicate that mutations in the elastin gene cause SVAS and suggest that elastin exons 28-36 may encode critical domains for vascular development.

Native and a synthetic analogue of the malignancy-associated parathyroid hormone-like protein have in vitro transforming growth factor-like properties.

A human parathyroid-like protein (PLP) has recently been isolated and cloned from human tumors associated with the paraneoplastic syndrome, humoral hypercalcemia of malignancy. PLP shares NH2-terminal amino acid sequence similarity with PTH but has a unique primary structure thereafter. Studies reported to date have indicated that both native and synthetic amino-terminal PLP polypeptides display actions in vivo and in vitro that are similar to those of PTH. We report here that purified native PLP and synthetic 36Tyr(1-36)amide human PLP induce epidermal growth factor-dependent transformation of NRK 49F cells in soft agar. Further, the synthetic peptide induces a significant increase in the biosynthesis of fibronectin by human dermal fibroblasts. (1-34)PTH does not display either of these biological activities. These data indicate that there are qualitative differences between PTH and the recently identified PLP. The latter hormone appears to possess transforming growth factor-like properties that may be relevant to its physiological actions.

Heritability of resistance to infestation with the body louse, Bovicola ovis, in Romney sheep bred for differences in resistance or resilience to gastro-intestinal nematode parasites.

The inheritance of resistance to louse infestation and the related allergic skin disease, cockle, was examined in Romney lambs. The lambs used in the study were the 2001- and 2004-born progeny of four experimental breeding lines ("Resistant", "Susceptible", "Resilient" and "Control") developed as part of a long-term study of the genetics of host resistance (maintenance of low faecal egg count (FEC) under nematode challenge) or resilience (maintenance of health and productivity under nematode challenge irrespective of FEC) to nematode parasites in sheep. Between 13 and 22 progeny (equally distributed between males and females, where possible) from each of five sires in each line were selected each year for this trial. All lambs (n=701) were examined for lice (Bovicola ovis) before artificial infestation; in 2001 the lambs were free of natural infestation, whilst in 2004 naturally acquired infestation was evident. In November 2001 and May 2002, approximately 60 B. ovis were transferred to each lamb, followed by monitoring at approximately 2-monthly intervals until August 2002. Similar procedures, but with fewer monitoring times, were repeated on the 2004 lambs. Overall, lambs in the Control line were significantly more susceptible to louse infestation and cockle compared with those in the other three lines (P<0.001). Least squares-means (SEM) of log-transformed louse score for the control, resistant, susceptible and resilient lines, respectively, were 2.178 (0.045), 1.499 (0.050), 1.618 (0.050) and 1.587 (0.044), and for cockle score were 1.36 (0.05), 0.76 (0.05), 0.95 (0.05) and 0.78 (0.05). From all progeny together, the heritability of log-transformed louse score was 0.22 (Standard Error (SE) 0.06) in autumn and 0.34 (SE 0.08) in winter, with a value of 0.44 (SE 0.09) when these data were combined. These estimates were similar to those obtained for resistance to gastro-intestinal nematodes in these breeding lines, using log-transformed FECs. Heritability estimates for cockle score in autumn, winter and when combined were 0.06 (SE 0.04), 0.45 (SE 0.09) and 0.40 (SE 0.09), respectively. The genetic correlations of mean log-transformed louse score with mean cockle score and levels of two different louse antigens in wool were, respectively, 0.97 (SE 0.04), 0.96 (SE 0.08) and 0.95 (SE 0.09). However, there was no significant genetic correlation between louse scores and FEC. These results suggest that selective breeding would be effective in reducing louse infestation and cockle in sheep, but that differences in louse burdens were not related to differences in nematode burdens as indicated by FECs.

A review of genetic resistance to disease in Bos taurus cattle.

Cattle show considerable variability in their responses to a wide range of disease challenges, and much of the variability is genetic. This review highlights genetic variation in disease susceptibility in Bos taurus cattle, with variation found at the breed level and also within breeds. Disease challenges come from bacteria and viruses, parasites and feed-borne toxins. For an animal to survive, it needs its own mechanisms for resisting these challenges, or for being resilient to them, or it must be protected artificially from them. Disease challenges have been classified as 'diseases from without', but there is also another class of genetic diseases resulting from inborn errors of metabolism, which might be called 'diseases from within'. Degrees of inheritance (heritabilities) are reviewed for a range of economically important traits including resistance to mastitis, ketosis, lameness, nematode parasites, external parasites, eye disease, respiratory disorders, tuberculosis, brucellosis, Johne's disease, foot-and-mouth disease, bovine spongiform encephalopathy, metabolic disorders caused by toxins found on the feed, and threshold levels of minerals and metabolites. Many, but not all, of the above require an immune response as part of the fight against an external challenge, and measurements have been made of general immune response as a way of describing or predicting how an animal will respond. There are now some examples of industry or breed societies applying selection for resistance to one or more diseases as part of a complete breeding objective in dairy cattle, beef cattle or dual purpose livestock. In most cases, industry and breed societies are in the early stages of applying effective selection pressure for resistance to specific cattle diseases, with the notable exceptions of Scandinavian cattle schemes, which lead the world in this respect.

Marinobufagenin impairs first trimester cytotrophoblast differentiation.

Preeclampsia is a pregnancy-specific syndrome that is the leading cause of maternal death during pregnancy in the developed world. In preeclampsia, a combination of immunological, genetic and environmental factors can lead to altered cytotrophoblast (CTB) invasion of the uterine wall, a process that is critical for normal placental development and pregnancy maintenance. Marinobufagenin (MBG) is an endogenous inhibitor of the sodium pump Na(+)/K(+) ATPase, and increased plasma MBG is associated with hypertension, chronic renal failure and preeclampsia. In the present study, the effects of MBG on CTB differentiation and invasion were investigated utilizing the first trimester extravillous CTB cell line SGHPL-4. MBG significantly inhibited SGHPL-4 proliferation in a dose-dependent manner. In addition, growth factor-induced migration and invasion were significantly inhibited by MBG treatment. These findings demonstrate that MBG impairs CTB differentiation along the invasive pathway. Elucidating the mechanisms by which MBG impairs placental development may increase our understanding of fetal and maternal pathologies associated with preeclampsia.