Showing items 1 - 5 of 5

Your selections:

Genes influencing circadian differences in blood pressure in hypertensive mice

- Marques, Francine, Campain, Anna, Davern, Pamela, Yang, Yee, Head, Geoffrey, Morris, Brian

  • Authors: Marques, Francine , Campain, Anna , Davern, Pamela , Yang, Yee , Head, Geoffrey , Morris, Brian
  • Date: 2011
  • Type: Text , Journal article
  • Relation: PLoS ONE Vol. 6, no. 4 (April 2011 2011), p. e19203
  • Full Text:
  • Reviewed:
  • Description: Essential hypertension is a common multifactorial heritable condition in which increased sympathetic outflow from the central nervous system is involved in the elevation in blood pressure (BP), as well as the exaggerated morning surge in BP that is a risk factor for myocardial infarction and stroke in hypertensive patients. The Schlager BPH/2J mouse is a genetic model of hypertension in which increased sympathetic outflow from the hypothalamus has an important etiological role in the elevation of BP. Schlager hypertensive mice exhibit a large variation in BP between the active and inactive periods of the day, and also show a morning surge in BP. To investigate the genes responsible for the circadian variation in BP in hypertension, hypothalamic tissue was collected from BPH/2J and normotensive BPN/3J mice at the 'peak' (n = 12) and 'trough' (n = 6) of diurnal BP. Using Affymetrix GeneChip® Mouse Gene 1.0 ST Arrays, validation by quantitative real-time PCR and a statistical method that adjusted for clock genes, we identified 212 hypothalamic genes whose expression differed between 'peak' and 'trough' BP in the hypertensive strain. These included genes with known roles in BP regulation, such as vasopressin, oxytocin and thyrotropin releasing hormone, as well as genes not recognized previously as regulators of BP, including chemokine (C-C motif) ligand 19, hypocretin and zinc finger and BTB domain containing 16. Gene ontology analysis showed an enrichment of terms for inflammatory response, mitochondrial proton-transporting ATP synthase complex, structural constituent of ribosome, amongst others. In conclusion, we have identified genes whose expression differs between the peak and trough of 24-hour circadian BP in BPH/2J mice, pointing to mechanisms responsible for diurnal variation in BP. The findings may assist in the elucidation of the mechanism for the morning surge in BP in essential hypertension.
  • Description: C1

Longer leukocyte telomeres are associated with ultra-endurance exercise independent of cardiovascular risk factors

- Denham, Joshua, Nelson, Christopher, O'Brien, Brendan, Nankervis, Scott, Denniff, Matthew, Harvey, Jack, Marques, Francine, Codd, Veryan, Zukowska-Szczechowska, Ewa, Samani, Nilesh, Tomaszewski, Maciej, Charchar, Fadi

Acute exercise leads to regulation of Telomere-Associated genes and MicroRNA expression in immune Cells

- Chilton, Warrick, Marques, Francine, West, Jenny, Kannourakis, George, Berzins, Stuart, O'Brien, Brendan, Charchar, Fadi

  • Authors: Chilton, Warrick , Marques, Francine , West, Jenny , Kannourakis, George , Berzins, Stuart , O'Brien, Brendan , Charchar, Fadi
  • Date: 2014
  • Type: Text , Journal article
  • Relation: PloS One Vol. 9, no. 4 (2014), p. e92088
  • Full Text:
  • Reviewed:
  • Description: Telomeres are specialized nucleoprotein structures that protect chromosomal ends from degradation. These structures progressively shorten during cellular division and can signal replicative senescence below a critical length. Telomere length is predominantly maintained by the enzyme telomerase. Significant decreases in telomere length and telomerase activity are associated with a host of chronic diseases; conversely their maintenance underpins the optimal function of the adaptive immune system. Habitual physical activity is associated with longer leukocyte telomere length; however, the precise mechanisms are unclear. Potential hypotheses include regulation of telomeric gene transcription and/or microRNAs (miRNAs). We investigated the acute exercise-induced response of telomeric genes and miRNAs in twenty-two healthy males (mean age = 24.1±1.55 years). Participants undertook 30 minutes of treadmill running at 80% of peak oxygen uptake. Blood samples were taken before exercise, immediately post-exercise and 60 minutes post-exercise. Total RNA from white blood cells was submitted to miRNA arrays and telomere extension mRNA array. Results were individually validated in white blood cells and sorted T cell lymphocyte subsets using quantitative real-time PCR (qPCR). Telomerase reverse transcriptase (TERT) mRNA (P = 0.001) and sirtuin-6 (SIRT6) (P<0.05) mRNA expression were upregulated in white blood cells after exercise. Fifty-six miRNAs were also differentially regulated post-exercise (FDR <0.05). In silico analysis identified four miRNAs (miR-186, miR-181, miR-15a and miR-96) that potentially targeted telomeric gene mRNA. The four miRNAs exhibited significant upregulation 60 minutes post-exercise (P<0.001). Telomeric repeat binding factor 2, interacting protein (TERF2IP) was identified as a potential binding target for miR-186 and miR-96 and demonstrated concomitant downregulation (P<0.01) at the corresponding time point. Intense cardiorespiratory exercise was sufficient to differentially regulate key telomeric genes and miRNAs in white blood cells. These results may provide a mechanistic insight into telomere homeostasis and improved immune function and physical health. Funding NHMRC

Resveratrol, by modulating RNA processing factor levels, can influence the alternative splicing of Pre-mRNAs

- Markus, M. Andrea, Marques, Francine, Morris, Brian

  • Authors: Markus, M. Andrea , Marques, Francine , Morris, Brian
  • Date: 2011
  • Type: Text , Journal article
  • Relation: PLoS ONE Vol. 6, no. 12 (2011), p. e28926
  • Full Text:
  • Reviewed:
  • Description: Alternative pre-mRNA splicing defects can contribute to, or result from, various diseases, including cancer. Aberrant mRNAs, splicing factors and other RNA processing factors have therefore become targets for new therapeutic interventions. Here we report that the natural polyphenol resveratrol can modulate alternative splicing in a target-specific manner. We transfected minigenes of several alternatively spliceable primary mRNAs into HEK293 cells in the presence or absence of 1, 5, 20 and 50 μM resveratrol and measured exon levels by semi-quantitative PCR after separation by agarose gel electrophoresis. We found that 20 µg/ml and 50 µg/ml of resveratrol affected exon inclusion of SRp20 and SMN2 pre-mRNAs, but not CD44v5 or tau pre-mRNAs. By Western blotting and immunofluorescence we showed that this effect may be due to the ability of resveratrol to change the protein level but not the localization of several RNA processing factors. The processing factors that increased significantly were ASF/SF2, hnRNPA1 and HuR, but resveratrol did not change the levels of RBM4, PTBP1 and U2AF35. By means of siRNA-mediated knockdown we depleted cells of SIRT1, regarded as a major target of resveratrol, and showed that the effect on splicing was not dependent on SIRT1. Our results suggest that resveratrol might be an attractive small molecule to treat diseases in which aberrant splicing has been implicated, and justify more extensive research on the effects of resveratrol on the splicing machinery.
  • Description: C1

Plasma lipocalin-2/NGAL is stable over 12 weeks and is not modulated by exercise or dieting

- Nakai, Michael, Prestes, Priscilla, O’Brien, Brendan, Charchar, Fadi, Marques, Francine

  • Authors: Nakai, Michael , Prestes, Priscilla , O’Brien, Brendan , Charchar, Fadi , Marques, Francine
  • Date: 2021
  • Type: Text , Journal article
  • Relation: Scientific Reports Vol. 11, no. 1 (2021), p.
  • Full Text:
  • Reviewed:
  • Description: Amongst other immune cells, neutrophils play a key role in systemic inflammation leading to cardiovascular disease and can release inflammatory factors, including lipocalin-2 (LCN2). LCN2 drives cardiac hypertrophy and plays a role in maladaptive remodelling of the heart and has been associated with renal injury. While lifestyle factors such as diet and exercise are known to attenuate low-grade inflammation, their ability to modulate plasma LCN2 levels is unknown. Forty-eight endurance athletes and 52 controls (18–55 years) underwent measurement for various cardiovascular health indicators, along with plasma LCN2 concentration. No significant difference in LCN2 concentration was seen between the two groups. LCN2 was a very weak predictor or absent from models describing blood pressures or predicting athlete status. In another cohort, 57 non-diabetic overweight or obese men and post-menopausal women who fulfilled Adult Treatment Panel III metabolic syndrome criteria were randomly allocated into either a control, modified Dietary Approaches to Stop Hypertension (DASH) diet, or DASH and exercise group. Pre- and post-intervention demographic, cardiovascular health indicators, and plasma LCN2 expression were measured in each individual. While BMI fell in intervention groups, LCN2 levels remained unchanged within and between all groups, as illustrated by strong correlations between LCN2 concentrations pre- and 12 weeks post-intervention (r = 0.743, P < 0.0001). This suggests that circulating LCN2 expression are stable over a period of at least 12 weeks and is not modifiable by diet and exercise. © 2021, The Author(s). *Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Priscilla Prestes, Brendan O'Brien, Fadi Charchar and Francine Marques” is provided in this record** .
  • 1