Obstetric and long-term kidney outcomes in renal transplant recipients: a 40 year single-centre study

Female renal transplant recipients of childbearing age may ask what the outcomes are for pregnancy and whether pregnancy will affect graft function. We analyzed obstetric and transplant outcomes among renal transplant recipients in our center who have been pregnant between 1973 and 2013. A case−cohort study was performed identifying 83 pairs of pregnant and non-pregnant controls matched for sex, age, transplant vintage, and creatinine. There were 138 pregnancies reported from 89 renal transplant recipients. There were live births in 74% of pregnancies with high prevalence of prematurity (61%), low birth weight (52%), and pre-eclampsia (14%). Lower eGFR (OR 0.98; p = 0.05) and higher uPCR (OR 1.86; p = 0.02) at conception were independent predictors for poor composite obstetric outcome. Lower eGFR (OR 0.98; p = 0.04), higher uPCR (OR 1.50; p = 0.04), and live organ donation (OR 0.35; p = 0.02) were predictors of ≥20% loss of eGFR between immediately pre-pregnancy and one yr after delivery. There was no difference in eGFR at one, five, and 10 yr in pregnant women compared with non-pregnant controls and a pregnancy was not associated with poorer 10-yr transplant or 20-yr patient survival. Despite high rates of obstetric complications, most women had successful pregnancies with good long-term transplant function

Short term exendin-4 treatment reduces markers of metabolic disorders in female offspring of obese rat dams

© 2015 Elsevier Ltd. Objectives: Maternal obesity imposes significant health risks in the offspring including diabetes and dyslipidemia. We previously showed that the hypoglycaemic agent exendin-4 (Ex-4) administered from weaning can reverse the maternal impact of 'transmitted disorders' in such offspring. However daily injection for six-weeks was required and the beneficial effect may lapse upon drug withdrawal. This study aimed to investigate whether short term Ex-4 treatment during suckling period in a rodent model can reverse transmitted metabolic disorders due to maternal obesity. Methods: Maternal obesity was induced in female Sprague Dawley rats by high-fat diet feeding for 6 weeks, throughout gestation and lactation. Female offspring were treated with Ex-4 (5. μg/kg/day) between postnatal day (P) 4 and 14. Female offspring were harvested at weaning (P20). Lipid and glucose metabolic markers were measured in the liver and fat. Appetite regulators were measured in the plasma and hypothalamus. Results: Maternal obesity significantly increased body weight, fat mass, and liver weight in the offspring. There was an associated inhibition of peroxisomal proliferator activated receptor gamma coactivator 1α (PGC1α), increased fatty acid synthase (FASN) expression in the liver, and reduced adipocyte triglyceride lipase (ATGL) expression. It also increased the plasma gut hormone ghrelin and reduced glucagon-like peptide-1. Ex-4 treatment partially reversed the maternal impact on adiposity and impaired lipid metabolism in the offspring, with increased liver PGC1α and inhibition of FASN mRNA expression. Ex-4 treatment also increased the expression of a novel fat depletion gene a2-zinc-glycoprotein 1 in the fat tissue. Conclusion: Short term Ex-4 treatment during the suckling period significantly improved the metabolic profile in the offspring from the obese mothers at weaning. Long-term studies are needed to follow such offspring to adulthood to examine the sustained effects of Ex-4 in preventing the development of metabolic disease

Leveraging DNA-Methylation Quantitative-Trait Loci to Characterize the Relationship between Methylomic Variation, Gene Expression, and Complex Traits

Characterizing the complex relationship between genetic, epigenetic, and transcriptomic variation has the potential to increase understanding about the mechanisms underpinning health and disease phenotypes. We undertook a comprehensive analysis of common genetic variation on DNA methylation (DNAm) by using the Illumina EPIC array to profile samples from the UK Household Longitudinal study. We identified 12,689,548 significant DNA methylation quantitative trait loci (mQTL) associations (p 60 human traits by using summary-data-based Mendelian randomization (SMR) to identify 1,662 pleiotropic associations between 36 complex traits and 1,246 DNAm sites. We also use SMR to characterize the relationship between DNAm and gene expression and thereby identify 6,798 pleiotropic associations between 5,420 DNAm sites and the transcription of 1,702 genes. Our mQTL database and SMR results are available via a searchable online database as a resource to the research community

Bigmelon:Tools for analysing large DNA methylation datasets

Motivation The datasets generated by DNA methylation analyses are getting bigger. With the release of the HumanMethylationEPIC micro-array and datasets containing thousands of samples, analyses of these large datasets using R are becoming impractical due to large memory requirements. As a result there is an increasing need for computationally efficient methodologies to perform meaningful analysis on high dimensional data. Results Here we introduce the bigmelon R package, which provides a memory efficient workflow that enables users to perform the complex, large scale analyses required in epigenome wide association studies (EWAS) without the need for large RAM. Building on top of the CoreArray Genomic Data Structure file format and libraries packaged in the gdsfmt package, we provide a practical workflow that facilitates the reading-in, preprocessing, quality control and statistical analysis of DNA methylation data. We demonstrate the capabilities of the bigmelon package using a large dataset consisting of 1193 human blood samples from the Understanding Society: UK Household Longitudinal Study, assayed on the EPIC micro-array platform. copy; 2018 The Author(s). Published by Oxford University Press.</p

Characterisation of Peptide5 systemic administration for treating traumatic spinal cord injured rats

© 2017, Springer-Verlag GmbH Germany. Systemic administration of a Connexin43 mimetic peptide, Peptide5, has been shown to reduce secondary tissue damage and improve functional recovery after spinal cord injury (SCI). This study investigated safety measures and potential off-target effects of Peptide5 systemic administration. Rats were subjected to a mild contusion SCI using the New York University impactor. One cohort was injected intraperitoneally with a single dose of fluorescently labelled Peptide5 and euthanised at 2 or 4 h post-injury for peptide distribution analysis. A second cohort received intraperitoneal injections of Peptide5 or a scrambled peptide and was culled at 8 or 24 h post-injury for the analysis of connexin proteins and systemic cytokine profile. We found that Peptide5 did not cross the blood-spinal cord barrier in control animals, but reached the lesion area in the spinal cord-injured animals without entering non-injured tissue. There was no evidence that the systemic administration of Peptide5 modulates Connexin43 protein expression or hemichannel closure in the heart and lung tissue of SCI animals. The expression levels of other major connexin proteins including Connexin30 in astrocytes, Connexin36 in neurons and Connexin47 in oligodendrocytes were also unaltered by systemic delivery of Peptide5 in either the injured or non-injured spinal cords. In addition, systemic delivery of Peptide5 had no significant effect on the plasma levels of cytokines, chemokines or growth factors. These data indicate that the systemic delivery of Peptide5 is unlikely to cause any off-target or adverse effects and may thus be a safe treatment option for traumatic SCI

L-Carnitine and extendin-4 improve outcomes following moderate brain contusion injury

© 2018, The Author(s). There is a need for pharmaceutical agents that can reduce neuronal loss and improve functional deficits following traumatic brain injury (TBI). Previous research suggests that oxidative stress and mitochondrial dysfunction play a major role in neuronal damage after TBI. Therefore, this study aimed to investigate two drugs known to have antioxidant effects, L-carnitine and exendin-4, in rats with moderate contusive TBI. L-carnitine (1.5 mM in drinking water) or exendin-4 (15 µg/kg/day, ip) were given immediately after the injury for 2 weeks. Neurological function and brain histology were examined (24 h and 6 weeks post injury). The rats with TBI showed slight sensory, motor and memory functional deficits at 24 h, but recovered by 6 weeks. Both treatments improved sensory and motor functions at 24 h, while only exendin-4 improved memory. Both treatments reduced cortical contusion at 24 h and 6 weeks, however neither affected gliosis and inflammatory cell activation. Oxidative stress was alleviated and mitochondrial reactive oxygen species was reduced by both treatments, however only mitochondrial functional marker protein transporter translocase of outer membrane 20 was increased at 24 h post injury. In conclusion, L-carnitine and exendin-4 treatments immediately after TBI can improve neurological functional outcome and tissue integrity by reducing oxidative stress

Rapid GFAP and Iba1 Expression Changes in the Female Rat Brain following Spinal Cord Injury

Spinal cord injury (SCI) is a devastating condition often associated with sleep disorders, mood change and depression. Evidence suggests that rapid changes to supporting glia may predispose individuals with SCI to such comorbidities. Here, we interrogated the expression of astrocyte- and microglial-specific markers glial fibrillary acidic protein (GFAP) and ionized calcium binding adaptor molecule 1 (Iba1) in the rat brain in the first 24 hours following spinal cord injury (SCI). Female Sprague Dawley rats underwent thoracic laminectomy; half of the rats received a mild contusion injury at the level of the T10 vertebral body (SCI group), the other half did not (Sham group). Twenty-four hours post-surgery the rats were sacrificed, and the amygdala, periaqueductal grey, prefrontal cortex, hypothalamus, lateral thalamus, hippocampus (dorsal and ventral) were collected. GFAP and Iba1 mRNA and protein levels were measured by real-time qPCR and Western blot. In SCI rats, GFAP mRNA and protein expression increased in the amygdala and hypothalamus (*p<0.05). In contrast, gene and protein expression decreased in the thalamus (**p<0.01) and dorsal hippocampus (*p<0.05 and **p<0.01, respectively). Interestingly, Iba1 transcripts and proteins were significantly diminished only in the dorsal (*p<0.05 and **p<0.01, respectively) and ventral hippocampus, where gene expression diminished (*p<0.05 for both mRNA and protein). Considered together, these findings demonstrate that as early as 24 hours post-SCI there are region-specific disruptions of GFAP and Iba1 transcript and protein levels in higher brain regions

Moderate traumatic brain injury is linked to acute behaviour deficits and long term mitochondrial alterations

© 2016 John Wiley & Sons Australia, Ltd Traumatic brain injury (TBI) remains one of the leading causes of death and disability worldwide. Mild TBI may lead to neuropsychiatric sequelae, including memory loss and motor impairment. Mitochondrial dysfunction and oxidative stress have a contributory role in several neurological disorders; however, their association with mitophagy in mild TBI is unclear. TBI was induced in female Sprague Dawley (SD) rats using a New York University Impactor (10 g, impactor head 2.5 mm diameter, weight drop 50 mm) and compared to sham surgery controls. The novel object recognition and error ladder tests were performed at 24 hours and for 6 weeks post injury, and the brains were examined histologically to confirm the extent of injury. Mitochondria manganese superoxide dismutase (MnSOD) and the oxidative phosphorylation (OXPHOS) complexes I-V (CI-CV), as well as mitophagy markers, dynamin related protein 1 (DRP-1), LC3A/B and PTEN-induced putative kinase 1 (PINK-1), were measured in the penumbra by western blot. At 24 hours sham rats performed as expected on a novel object recognition test while TBI rats showed cognitive deficits at the early time points. TBI rats also showed more early motor deficits on a horizontal ladder, compared with the sham rats. MnSOD, OXPHOS CI, CIII and CV protein levels were significantly lower in the TBI group at 24 hours. DRP-1, LC3A/B I and II, and PINK-1 were increased at 6 weeks suggesting abnormal mitophagy. Moderate TBI caused immediate cognitive and mild motor functional deficits in the rats that did not persist. Reduced antioxidative capacity and possibly compromised mitochondrial function may affect the long term functional recovery

InterpolatedXY: a two-step strategy to normalise DNA methylation microarray data avoiding sex bias

Motivation Data normalization is an essential step to reduce technical variation within and between arrays. Due to the different karyotypes and the effects of X chromosome inactivation, females and males exhibit distinct methylation patterns on sex chromosomes; thus, it poses a significant challenge to normalize sex chromosome data without introducing bias. Currently, existing methods do not provide unbiased solutions to normalize sex chromosome data, usually, they just process autosomal and sex chromosomes indiscriminately. Results Here, we demonstrate that ignoring this sex difference will lead to introducing artificial sex bias, especially for thousands of autosomal CpGs. We present a novel two-step strategy (interpolatedXY) to address this issue, which is applicable to all quantile-based normalization methods. By this new strategy, the autosomal CpGs are first normalized independently by conventional methods, such as funnorm or dasen; then the corrected methylation values of sex chromosome-linked CpGs are estimated as the weighted average of their nearest neighbors on autosomes. The proposed two-step strategy can also be applied to other non-quantile-based normalization methods, as well as other array-based data types. Moreover, we propose a useful concept: the sex explained fraction of variance, to quantitatively measure the normalization effect. Availability and implementation The proposed methods are available by calling the function ‘adjustedDasen’ or ‘adjustedFunnorm’ in the latest wateRmelon package (https://github.com/schalkwyk/wateRmelon), with methods compatible with all the major workflows, including minfi