Hyperglycemia, hypoxia and their combination exert oxidative stress and changes in antioxidant gene expression: studies on cultured rat embryos

INTRODUCTION: Hyperglycemia and hypoxia are well‐known teratogens that may affect many animal species, including man. We hypothesize that a combination of hypoxia and hyperglycemia will increase embryonic damage produced by either factor individually. We investigated the interrelationship between hyperglycemia and hypoxia and their effects on genes involved in the balance of embryonic redox status. METHODS: Rat embryos (10.5‐day‐old) were cultured for 28 hr in culture medium with about 6 mg/ml of glucose and 20% oxygen (hyperglycemia), with 10% oxygen (hypoxia) and 2.4 g/ml glucose (normal) or a combination of both 6 mg/ml glucose and 10% oxygen. Antioxidant capacity was determined by activity and gene expression of antioxidant enzymes: Cu/Zn SOD, Mn‐SOD, CAT, and GSH‐px using real time PCR. RESULTS: Hyperglycemia, hypoxia, or their combination, decreased embryonic growth and induced a high rate (62–78%) of anomalies mainly of the nervous system, heart, and limbs. CAT mRNA and GSH‐px mRNA were decreased in the malformed embryos exposed to hyperglycemia, to hypoxia or their combination. CAT mRNA was also decreased in the nonmalformed embryos subjected to hyperglycemia and hypoxia. Cu/Zn SOD mRNA was increased in all experimental embryos whether malformed or not, whereas Mn‐SOD was drastically decreased. Total SOD and CAT like activity were changed very little in the experimental embryos compared to controls. CONCLUSIONS: Both hyperglycemia, hypoxia, and their combination reduce embryonic growth and development, induce embryonic anomalies, and modify the expression of the principle antioxidant genes. However, hypoxia does not seem to enhance the damaging effects of hyperglycemia except its effects of embryonic growth. Birth Defects Res (Part B) 92:231–239, 2011. © 2011 Wiley‐Liss, Inc.     

ESR Detection of 1O2 Reveals Enhanced Redox Activity in Illuminated Cell Cultures

Low-energy visible light (LEVL) has previously been found to modulate various processes in different biological systems. One explanation for the stimulatory effect of LEVL is light-induced reactive oxygen species formation. In the present study, both sperm and skin cells were illuminated with LEVL and were found to generate singlet oxygen (¹O₂). The detection of ¹O₂ was performed using a trapping probe, 2,2,6,6-tetramethyl-4-piperidone, coupled with electron paramagnetic resonance spectroscopy. In addition, we have shown that, together with ¹O₂ generation, LEVL illumination increases the reductive capacity of the cells, which explains the difficulties encountered in ¹O₂ detection. The potential of visible light to change the cellular redox state may explain the recently observed biostimulative effects exerted by LEVL.     

Transferrin gene frequencies of feral and domestic goats in New Zealand

Abstract

Blood plasma from three populations of feral goats (Capra hircus L.) and from five domestic breeds was analysed by polyacrylamide gel electrophoresis. The albumin locus was monomorphic in all samples. The macroglobulin locus was variable but lacked resolution on the gel. The transferrin (Tf) locus was polymorphic. The only two Tf alleles observed (Tf A and Tf B) did not vary from those described by other authors. Gene frequencies of the two Tf alleles showed that one feral population could be distinguished from the other two. Gene frequencies of domestic breeds were variable and showed no definitive pattern. Domestic breed type could not be recognised in the feral populations on the basis of transferrin analysis alone.     

First insights into the metagenome of Egyptian mummies using next-generation sequencing

We applied, for the first time, next-generation sequencing (NGS) technology on Egyptian mummies. Seven NGS datasets obtained from five randomly selected Third Intermediate to Graeco-Roman Egyptian mummies (806 BC–124AD) and two unearthed pre-contact Bolivian lowland skeletons were generated and characterised. The datasets were contrasted to three recently published NGS datasets obtained from cold-climate regions, i.e. the Saqqaq, the Denisova hominid and the Alpine Iceman. Analysis was done using one million reads of each newly generated or published dataset. Blastn and megablast results were analysed using MEGAN software. Distinct NGS results were replicated by specific and sensitive polymerase chain reaction (PCR) protocols in ancient DNA dedicated laboratories. Here, we provide unambiguous identification of authentic DNA in Egyptian mummies. The NGS datasets showed variable contents of endogenous DNA harboured in tissues. Three of five mummies displayed a human DNA proportion comparable to the human read count of the Saqqaq permafrost-preserved specimen. Furthermore, a metagenomic signature unique to mummies was displayed. By applying a “bacterial fingerprint”, discrimination among mummies and other remains from warm areas outside Egypt was possible. Due to the absence of an adequate environment monitoring, a bacterial bloom was identified when analysing different biopsies from the same mummies taken after a lapse of time of 1.5 years. Plant kingdom representation in all mummy datasets was unique and could be partially associated with their use in embalming materials. Finally, NGS data showed the presence of Plasmodium falciparum and Toxoplasma gondii DNA sequences, indicating malaria and toxoplasmosis in these mummies. We demonstrate that endogenous ancient DNA can be extracted from mummies and serve as a proper template for the NGS technique, thus, opening new pathways of investigation for future genome sequencing of ancient Egyptian individuals.     

Embryo transfer in fallow deer (Dama dama): superovulation, embryo recovery and laparoscopic transfer of fresh and cryopreserved embryos

Multiple ovulation-embryo transfer (MOET) protocols for farmed fallow deer (Dama dama ) were investigated in a series of 3 experiments. A total of 37 donors, of either European (D.d. dama ; n = 30) or Mesopotamian hybrid (D.d. mesopotamica x D.d. dama ; n =7) genotype, each received an intravaginal silastic device containing 0.3 g progesterone (CIDR((R))-type G device) for 14 d and injections of 0.5 units ovine FSH (8 x 0.06 unit injections from Days 10 to 14 of device insertion) and 100 IU PMSG (either with the first or last FSH injection). All donors received laparoscopic intrauterine inseminations of fresh semen (50 x 10(6) spermatozoa) from a Mesopotamian sire 36 h after withdrawal of CIDR((R)) devices. Embryos were recovered by laparotomy on Day 6 (Day 0 = estrus). Mean ovulation rates for the 3 experiments were 8.1, 9.8 and 7.0, with no effect of PMSG timing (P>0.10). However, embryo recovery rates, albeit low throughout the study (29.6%), were significantly improved with later PMSG administration (33.9 vs 20.1%; P<0.05). Hybrid and European donors performed in a similar manner. A range of embryo development stages was recovered throughout the study. In 2 experiments laparoscopic transfer of embryos to 48 recipient does treated previously with intravaginal CIDR((R)) devices for 14 d yielded a total pregnancy rate of 37.5%. In the experiment with fresh embryos, the use of clenbuterol to reduce uterine turgidity resulted in a higher proportion of does conceiving (3 4 ; 75%) compared with that of the untreated does (0 6 , 0%; P<0.05). In the second experiment, in which all the does routinely received clenbuterol, 10 19 (53%) and 5 19 (26%) does conceived following the transfer of fresh and cryopreserved embryos, respectively (P<0.05). While the overall efficiency of the MOET program was low (equivalent of 0.9 to 1.0 surrogate pregnancies per donor), improvements in the recovery rate of transferable embryos have considerable potential for genetic improvement of farm stock and captive propagation of endangered Mesopotamian fallow deer through maternal surrogacy programs.     

Lysine and threonine metabolism are subject to complex patterns of regulation in Arabidopsis

To study the regulation of lysine and threonine metabolism in plants, we have transformed Arabidopsis thaliana with chimeric genes encoding the two bacterial enzymes dihydrodipicolinate synthase (DHPS) and aspartate kinase (AK). These bacterial enzymes are much less sensitive to feedback inhibition by lysine and threonine than their plant counterparts. Transgenic plants expressing the bacterial DHPS overproduced lysine, but lysine levels were quite variable within and between transgenic genotypes and there was no direct correlation between the levels of free lysine and the activity of DHPS. The most lysine-overproducing plants also exhibited abnormal phenotypes. However, these phenotypes were detected only at early stages of plant growth, while at later stages, new buds emerged that looked completely normal and set seeds. Wild-type plants exhibited relatively high levels of free threonine, suggesting that in Arabidopsis AK regulation may be more relaxed than in other plants. This was also supported by the fact that expression of the bacterial AK did not cause any dramatic elevation in this amino acid. Yet, the relaxed regulation of threonine synthesis in Arabidopsis was not simply due to a reduced sensitivity of the endogenous AK to feedback inhibition by lysine and threonine because growth of wild-type plants, but not of transgenic plants expressing the bacterial AK, was arrested in media containing these two amino acids. The present results, combined with previous studies from our laboratory, suggest that the regulation of lysine and threonine metabolism is highly variable among plant species and is subject to complex biochemical, physiological and environmental controls. The suitability of these transgenic Arabidopsis plants for molecular and genetic dissection of lysine and threonine metabolism is also discussed.     

Study on the influence of caffeic acid against sodium valproate–induced nephrotoxicity in rats

Renal injury is a hallmark adverse reaction to sodium valproate (SVP), and caffeic acid (CAFF) is a phenolic compound that has anti‐inflammatory and antioxsidant properties. So, this investigation was assessed to evaluate the nephrotoxic potential of SVP and the defensive impact of CAFF against SVP nephrotoxicity. SVP was given at a dose of 500 mg/kg (i.p.) once daily for 2 weeks, while CAFF was given at a dose of 50 mg/kg (orally), simultaneously with SVP. Concurrent treatment with CAFF reduced urea and creatinine, lipid peroxidation (malondialdehyde), tumor necrosis factor alpha (TNF‐α), interferon gamma (IFN‐γ), nuclear factor kappa B (NF‐κB/p65), and transforming growth factor β (TGF‐β) levels. However, with increased glutathione content, CAFF also halted the activated Notch signaling cascade. Furthermore, CAFF suppressed caspase‐3 and inducible nitric oxide synthase expressions. To conclude, on the basis of the results obtained, CAFF proved to protect against SVP‐induced nephrotoxicity via its antioxidant, anti‐inflammatory, and antiapoptotic properties.     

Modulatory effects of some natural products on hepatotoxicity induced by combination of sodium valproate and paracetamol in rats

Possible hepatoprotective effect of Curcuma longa and/or Nigella sativa against hepatotoxicity induced by coadministration of sodium valproate (SV) and paracetamol was studied. Rats were divided into 10 groups, control groups 1, 2, 3, and 4 received vehicles, C. longa (200 mg/kg, p.o.), N. sativa (250 mg/kg, p.o.), or both herbs for 21 days, respectively. Toxicity groups 5, 6, and 7 received SV (300 mg/kg, i.p.), paracetamol (1000 mg/kg, p.o.) for the last 4 days or both for 21 days, respectively. Protection groups 8, 9, and 10 received C. longa, N. sativa, or both, respectively, 1 h before the administration of both the drugs for 21 days. SV and/or paracetamol significantly increased aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), total bilirubin, relative liver/body weight ratio, malondialdehyde (MDA), tumor necrosis factor alpha (TNF‐α), and caspase‐3 (Casp‐3) while significantly decreased albumin, total protein, glutathione (GSH) reduced, GSH peroxidase, and superoxide dismutase (SOD). Preadministration of C. longa and/or N. sativa caused protective effect against the hepatotoxicity induced by both drugs.     

Triassic turtle tracks and the origin of turtles

Turtle (Testudines) tracks, Chelonipus torquatus, reported from the early Middle Triassic (Anisian) of Germany, and Chelonipus isp. from the late Early Triassic (Spathian) of Wyoming and Utah, are the oldest fossil evidence of turtles, but have been omitted in recent discussions of turtle origins. These tracks provide significant clues as to how early the turtle Bauplan originated. Turtle trackways are quite distinctive: the manus and pes form tracks nearly parallel to the midline and indicate an unusually wide gait in which the trackway width is nearly equal to the stride length. These tracks do not fit what would be expected to be made by Triassic Pappochelys or Odontochelys, a supposed prototurtle and an early turtle, respectively. In contrast, these tracks are consistent with what would be expected from the Triassic turtles Proganochelys and Palaeochersis. The features inferred to be present in Triassic turtle tracks support the notion that Odontochelys is a derived aquatic branch of the turtle stem lineage rather than the ancestral state of all turtles. Chelonipus also resembles the Permian track Pachypes dolomiticus, generally assigned to a pareiasaur trackmaker. These revelations highlight the need to consider all available evidence regarding turtle origins, rather than just the body fossils.