Showing items 1 - 20 of 116

A modified MTS proliferation assay for suspended cells to avoid the interference by hydralazine and β-Mercaptoethanol

- Wang, Yutang, Nguyen, Dinh, Anesi, Jack, Kelly, Jason, Ahmady, Fahima, Charchar, Fadi

  • Authors: Wang, Yutang , Nguyen, Dinh , Anesi, Jack , Kelly, Jason , Ahmady, Fahima , Charchar, Fadi
  • Date: 2021
  • Type: Text , Journal article
  • Relation: Assay and Drug Development Technologies Vol. 19, no. 3 (2021), p. 184-190. https://purl.org/au-research/grants/nhmrc/1062671
  • Full Text:
  • Reviewed:
  • Description: The 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay is one of the most commonly used tests of cell proliferation. Hydralazine has been reported to interfere with the performance of the MTS assay when used on adherent cells. This study aimed to investigate whether hydralazine interferes with the performance of the MTS assay on suspended cells. THP-1 (a monocytic leukemia cell line) cells were cultured in the presence or absence of hydralazine (0, 10, 50, 100, and 500 μM) for 2 or 24 h. Cell numbers were analyzed using the MTS, trypan blue exclusion, or microscopic assays. A modified version of the standard MTS assay was established by centrifuging the cells and replacing the test medium with fresh culture medium immediately before the addition of the MTS reagent. Culture of THP-1 cells with hydralazine at concentrations of 50, 100, and 500 μM for 2 h increased absorbance (p < 0.001) in the standard MTS assay, whereas both the trypan blue exclusion assay and microscopy suggested no change in cell numbers. Culture of THP-1 cells with 100 and 500 μm hydralazine for 24 h increased absorbance (p < 0.05) in the standard MTS assay; however, trypan blue exclusion and microscopy suggested a decrease in cell numbers. In a cell-free system, hydralazine (100 and 500 μM) increased absorbance in a time- and concentration-dependent manner. The modified MTS assay produced results consistent with trypan blue exclusion and microscopy using THP-1 cells. In addition, the modified MTS assay produced reliable results when K562 and Jurkat cells were incubated with hydralazine or β-mercaptoethanol (βME). In conclusion, a simple modification of the standard MTS assay overcame the interference of hydralazine and βME when assessing suspended cells. © Copyright 2021, Mary Ann Liebert, Inc., publishers 2021. *Please note that there are multiple authors for this article therefore only the name of the Federation University Australia affiliates “Yutang Wang, Dinh Nguyen, Jack Anesi, Jason Kelly, Fahima Ahmady, Fadi Charchar" is provided in this record**

Epigenome-wide association study of kidney function identifies trans-ethnic and ethnic-specific loci

- Breeze, Charles, Batorsky, Anna, Lee, Mi, Szeto, Mindy, Charchar, Fadi

  • Authors: Breeze, Charles , Batorsky, Anna , Lee, Mi , Szeto, Mindy , Charchar, Fadi
  • Date: 2021
  • Type: Text , Journal article
  • Relation: Genome Medicine Vol. 13, no. 1 (Apr 30 2021), p.
  • Full Text:
  • Reviewed:
  • Description: Background DNA methylation (DNAm) is associated with gene regulation and estimated glomerular filtration rate (eGFR), a measure of kidney function. Decreased eGFR is more common among US Hispanics and African Americans. The causes for this are poorly understood. We aimed to identify trans-ethnic and ethnic-specific differentially methylated positions (DMPs) associated with eGFR using an agnostic, genome-wide approach. Methods The study included up to 5428 participants from multi-ethnic studies for discovery and 8109 participants for replication. We tested the associations between whole blood DNAm and eGFR using beta values from Illumina 450K or EPIC arrays. Ethnicity-stratified analyses were performed using linear mixed models adjusting for age, sex, smoking, and study-specific and technical variables. Summary results were meta-analyzed within and across ethnicities. Findings were assessed using integrative epigenomics methods and pathway analyses. Results We identified 93 DMPs associated with eGFR at an FDR of 0.05 and replicated 13 and 1 DMPs across independent samples in trans-ethnic and African American meta-analyses, respectively. The study also validated 6 previously published DMPs. Identified DMPs showed significant overlap enrichment with DNase I hypersensitive sites in kidney tissue, sites associated with the expression of proximal genes, and transcription factor motifs and pathways associated with kidney tissue and kidney development. Conclusions We uncovered trans-ethnic and ethnic-specific DMPs associated with eGFR, including DMPs enriched in regulatory elements in kidney tissue and pathways related to kidney development. These findings shed light on epigenetic mechanisms associated with kidney function, bridging the gap between population-specific eGFR-associated DNAm and tissue-specific regulatory context.

Establishment of sex difference in circulating uric acid is associated with higher testosterone and lower sex hormone-binding globulin in adolescent boys

- Wang, Yutang, Charchar, Fadi

  • Authors: Wang, Yutang , Charchar, Fadi
  • Date: 2021
  • Type: Text , Journal article
  • Relation: Scientific Reports Vol. 11, no. 1 (2021), p.
  • Relation: https://purl.org/au-research/grants/nhmrc/1062671
  • Full Text:
  • Reviewed:
  • Description: Men have higher circulating levels of uric acid than women. This sex difference is suspected to be a result of suppressive effects of estradiol on uric acid. If so, estradiol would be inversely associated with circulating uric acid. This study aimed to test this hypothesis. This cross-sectional study included 9472 participants (weighted sample size of 184,342,210) aged 12–80 years from the 2013 to 2016 US National Health and Nutrition Examination Survey. Associations of sex hormones with uric acid were analyzed using weighted least squares regression, adjusting for demographic characteristics, lifestyle risk factors, and comorbidities. Neither free nor bioavailable estradiol was inversely associated with circulating uric acid in adolescent boys or girls, or adult men or women, or perimenopausal women after full adjustment. The sex difference in uric acid was established during adolescence as a result of a dramatic increase in uric acid in adolescent boys. During adolescence, the increase in estradiol in girls over time was accompanied by a relatively unchanged level of uric acid. All three fractions of estradiol (free, bioavailable, and total) were positively associated with uric acid in adolescent boys and girls after full adjustment. In adolescent boys, all three fractions of testosterone were positively associated with serum uric acid, and sex hormone-binding globulin was inversely associated with uric acid after full adjustment. These results suggest that estradiol is not inversely associated with circulating uric acid in adolescents and the establishment of sex difference in circulating uric acid during adolescence is associated with higher testosterone and lower sex hormone-binding globulin in adolescent boys. © 2021, The Author(s).

Hyperuricemia is independently associated with hypertension in men under 60 years in a general Chinese population

- Qian, Tingting, Sun, Hui, Xu, Qun, Charchar, Fadi, Wang, Yutang

  • Authors: Qian, Tingting , Sun, Hui , Xu, Qun , Charchar, Fadi , Wang, Yutang
  • Date: 2021
  • Type: Text , Journal article
  • Relation: Journal of Human Hypertension Vol. 35, no. 11 (2021), p. 1020-1028
  • Relation: https://purl.org/au-research/grants/nhmrc/1062671
  • Full Text: false
  • Reviewed:
  • Description: Hyperuricemia has been associated with hypertension, however, whether this association exists across all decades of adult life is unknown. This study aimed to assess the association between hyperuricemia and hypertension in relation to age. This retrospective cross-sectional study included a total of 22,556 adult Chinese people who attended Health Physical Examination in a Chinese hospital. Participants were aged between 18 and 95 years (mean [standard deviation], 45.4 [14.0]). Serum uric acid levels and blood pressure were measured. Associations between serum uric acid and blood pressure, and between hyperuricemia and hypertension diagnosis were analyzed using linear or logistic regression, adjusting for confounding risk factors including age, sex, total cholesterol, high-density lipoprotein cholesterol, and fasting blood glucose. Sub-analysis was stratified by age and sex. Before adjustment, high serum uric acid was associated with higher systolic blood pressure (β = 0.214, P < 0.001) and higher diastolic blood pressure (β = 0.271, P < 0.001). Hyperuricemia was associated with hypertension diagnosis (OR, 1.763; 95% CI, 1.635–1.901; P < 0.001) in an unadjusted analysis. These findings remained significant after adjusting for confounding factors. Sub-analysis suggested that the association between uric acid and blood pressure was weaker in older age groups and the association between hyperuricemia and hypertension was limited to people under 60 years. Hyperuricemia was independently associated with hypertension diagnosis in men but not in women, and the independent association between hyperuricemia and hypertension only presented in men under 60 years. This study suggests that hyperuricemia is independently associated with hypertension in Chinese men under 60 years. © 2020, The Author(s), under exclusive licence to Springer Nature Limited part of Springer Nature. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Fadi Charchar and Yutang Wang” is provided in this record**

Noncoding genes on sex chromosomes and their function in sex determination, dosage compensation, male traits, and diseases

- Maier, Michelle, McInerney, Molly-Rose, Graves, Jennifer, Charchar, Fadi

  • Authors: Maier, Michelle , McInerney, Molly-Rose , Graves, Jennifer , Charchar, Fadi
  • Date: 2021
  • Type: Text , Journal article , Review
  • Relation: Sexual Development Vol. 15, no. 5-6 (2021), p. 432-440
  • Relation: http://purl.org/au-research/grants/nhmrc/1123472
  • Full Text:
  • Reviewed:
  • Description: The mammalian Y chromosome has evolved in many species into a specialized chromosome that contributes to sex development among other male phenotypes. This function is well studied in terms of protein-coding genes. Less is known about the noncoding genome on the Y chromosome and its contribution to both sex development and other traits. Once considered junk genetic material, noncoding RNAs are now known to contribute to the regulation of gene expression and to play an important role in refining cellular functions. The prime examples are noncoding genes on the X chromosome, which mitigate the differential dosage of genes on sex chromosomes. Here, we discuss the evolution of noncoding RNAs on the Y chromosome and the emerging evidence of how micro, long, and circular noncoding RNAs transcribed from the Y chromosome contribute to sex differentiation. We briefly touch on emerging evidence that these noncoding RNAs also contribute to some other important clinical phenotypes in humans. © 2021 S. Karger AG. All rights reserved.

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** .

Plasma proteomics of renal function: A transethnic meta-analysis and mendelian randomization study

- Matías-García, Pamela, Wilson, Rory, Guo, Qi, Zaghlool, Shaza, Charchar, Fadi

  • Authors: Matías-García, Pamela , Wilson, Rory , Guo, Qi , Zaghlool, Shaza , Charchar, Fadi
  • Date: 2021
  • Type: Text , Journal article
  • Relation: Journal of the American Society of Nephrology Vol. 32, no. 7 (2021), p. 1747-1763
  • Full Text:
  • Reviewed:
  • Description: Background Studies on the relationship between renal function and the human plasma proteome have identified several potential biomarkers. However, investigations have been conducted largely in European populations, and causality of the associations between plasma proteins and kidney function has never been addressed. Methods A cross-sectional study of 993 plasma proteins among 2882 participants in four studies of European and admixed ancestries (KORA, INTERVAL, HUNT, QMDiab) identified transethnic associations between eGFR/CKD and proteomic biomarkers. For the replicated associations, two-sample bidirectional Mendelian randomization (MR) was used to investigate potential causal relationships. Publicly available datasets and transcriptomic data from independent studies were used to examine the association between gene expression in kidney tissue and eGFR. Results In total, 57 plasma proteins were associated with eGFR, including one novel protein. Of these, 23 were additionally associated with CKD. The strongest inferred causal effect was the positive effect of eGFR on testican-2, in line with the known biological role of this protein and the expression of its protein-coding gene (SPOCK2) in renal tissue. We also observed suggestive evidence of an effect of melanoma inhibitory activity (MIA), carbonic anhydrase III, and cystatin-M on eGFR. Conclusions In a discovery-replication setting, we identified 57 proteins transethnically associated with eGFR. The revealed causal relationships are an important stepping stone in establishing testican-2 as a clinically relevant physiological marker of kidney disease progression, and point to additional proteins warranting further investigation. © 2021 by the American Society of Nephrology

Reduced renal function may explain the higher prevalence of hyperuricemia in older people

- Wang, Yutang, Zhang, Wanlin, Qian, Tingting, Sun, Hui, Xu, Qun, Hou, Xujuan, Hu, Wenqi, Zhang, Guang, Drummond, Grant, Sobey, Chris, Charchar, Fadi, Golledge, Jonathan, Yang, Guang

  • Authors: Wang, Yutang , Zhang, Wanlin , Qian, Tingting , Sun, Hui , Xu, Qun , Hou, Xujuan , Hu, Wenqi , Zhang, Guang , Drummond, Grant , Sobey, Chris , Charchar, Fadi , Golledge, Jonathan , Yang, Guang
  • Date: 2021
  • Type: Text , Journal article
  • Relation: Scientific Reports Vol. 11, no. 1 (2021), p.
  • Relation: https://purl.org/au-research/grants/nhmrc/1062671
  • Full Text:
  • Reviewed:
  • Description: This study aimed to investigate the contribution of renal dysfunction to enhanced hyperuricemia prevalence in older people. A cohort of 13,288 Chinese people aged between 40 and 95 years were recruited from January to May 2019. Serum uric acid concentration and estimated glomerular filtration rate [eGFR] were measured. The associations between age or eGFR and serum uric acid or hyperuricemia were analyzed using linear or binary logistic regression adjusting for risk factors. Uric acid concentration and prevalence of hyperuricemia were greater in older participants. Adjustment for reduced renal function (eGFR < 60 mL/min/1.73 m2) eliminated the associations between older age and higher uric acid concentration and between older age and higher prevalence of hyperuricemia diagnosis, whereas adjustment for other risk factors did not change those associations. Lower eGFR was associated with higher uric acid concentration both before (β = − 0.296, P < 0.001) and after adjustment for age (β = − 0.313, P < 0.001). Reduced renal function was associated with hyperuricemia diagnosis both before (odds ratio, OR, 3.64; 95% CI 3.10–4.28; P < 0.001) and after adjustment for age (adjusted OR, 3.82; 95% CI 3.22–4.54; P < 0.001). Mean serum uric acid and prevalence of hyperuricemia were higher in people with eGFR < 60 mL/min/1.73 m2 than those with eGFR ≥ 60 mL/min/1.73 m2. The prevalence of reduced renal function increased with older age (P < 0.001). This study suggests that reduced renal function can explain the increased uric acid levels and hyperuricemia diagnoses in older people. © 2021, The Author(s).

Secondary stroke prevention in polish adults: Results from the lipidogram2015 study

- Labuz-Roszak, Beata, Banach, Maciej, Skrzypek, Michal, Windak, Adam, Charchar, Fadi

  • Authors: Labuz-Roszak, Beata , Banach, Maciej , Skrzypek, Michal , Windak, Adam , Charchar, Fadi
  • Date: 2021
  • Type: Text , Journal article
  • Relation: Journal of Clinical Medicine Vol. 10, no. 19 (2021), p.
  • Full Text:
  • Reviewed:
  • Description: Background: The purpose of the study was to evaluate secondary stroke prevention in Poland and its association with sociodemographic factors, place of residence, and concomitant cardiovascular risk factors. Material and methods: From all patients in LIPIDOGRAM2015 Study (n = 13,724), 268 subjects had a history of ischaemic stroke and were included. Results: 165 subjects (61.6%) used at least one preventive medication. Oral antiplatelet and anticoagulation agents were used by 116 (43.3%) and 70 (26.1%) patients, respectively. Only 157 (58.6%) participants used lipid-lowering drugs, and 205 (76.5%) were treated with antihypertensive drugs. Coronary heart disease (CHD) and dyslipidaemia were associated with antiplatelet treatment (p = 0.047 and p = 0.012, respectively). A history of atrial fibrillation, CHD, and previous myocardial infarction correlated with anticoagulant treatment (p = 0.001, p = 0.011, and p < 0.0001, respectively). Age, gender, time from stroke onset, place of residence, and level of education were not associated with antiplatelet or anticoagulant treatment. Only 31.7% of patients were engaged in regular physical activity, 62% used appropriate diet, and 13.6% were current smokers. Conclusions: In Poland drugs and lifestyle modification for secondary stroke prevention are not commonly adhered to. Educational programmes for physicians and patients should be developed to improve application of effective secondary prevention of stroke. © 2021 by the authors. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Fadi Charchar” is provided in this record**

The differences in the prevalence of cardiovascular disease, its risk factors, and achievement of therapeutic goals among urban and rural primary care patients in Poland: Results from the LIPIDOGRAM 2015 study

- Studziński, Krzysztof, Tomasik, Tomasz, Windak, Adam, Banach, Maciej, Charchar, Fadi

  • Authors: Studziński, Krzysztof , Tomasik, Tomasz , Windak, Adam , Banach, Maciej , Charchar, Fadi
  • Date: 2021
  • Type: Text , Journal article
  • Relation: Journal of Clinical Medicine Vol. 10, no. 23 (2021), p.
  • Full Text:
  • Reviewed:
  • Description: A nationwide cross-sectional study, LIPIDOGRAM2015, was carried out in Poland in the years 2015 and 2016. A total of 438 primary care physicians enrolled 13,724 adult patients that sought medical care in primary health care practices. The prevalence of hypertension, diabetes mellitus, dyslipidaemia, and CVD were similar in urban and rural areas (49.5 vs. 49.4%; 13.7 vs. 13.1%; 84.2 vs. 85.2%; 14.4 vs. 14.2%, respectively). The prevalence of obesity (32.3 vs. 37.5%, p < 0.01) and excessive waist circumference (77.5 vs. 80.7%, p < 0.01), as well as abdominal obesity (p = 43.2 vs. 46.4%, p < 0.01), were higher in rural areas in both genders. Mean levels of LDL-C (128 vs. 130 mg/dL, p = 0.04) and non-HDL-C (147 vs. 148 mg/dL, p = 0.03) were slightly higher in rural populations. Altogether, 14.3% of patients with CVD from urban areas and 11.3% from rural areas reached LDL <70 mg/dL (p = 0.04). There were no important differences in the prevalence of hypertension, diabetes, dyslipidaemia, and CVD, or in mean levels of blood pressure, cholesterol fractions, glucose, and HbA1c between Polish urban and rural primary care patient populations. A high proportion of patients in cities and an even-higher proportion in rural areas did not reach the recommended targets for blood pressure, LDL-C, and HbA1c, indicating the need for novel CVD-prevention programs. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Fadi Charchar” is provided in this record**

Uncovering genetic mechanisms of hypertension through multi-omic analysis of the kidney

- Eales, James, Jiang, Xiao, Xu, Xiaoguang, Prestes, Priscilla, Charchar, Fadi

  • Authors: Eales, James , Jiang, Xiao , Xu, Xiaoguang , Prestes, Priscilla , Charchar, Fadi
  • Date: 2021
  • Type: Text , Journal article
  • Relation: Nature Genetics Vol. 53, no. 5 (2021), p. 630-637
  • Full Text: false
  • Reviewed:
  • Description: The kidney is an organ of key relevance to blood pressure (BP) regulation, hypertension and antihypertensive treatment. However, genetically mediated renal mechanisms underlying susceptibility to hypertension remain poorly understood. We integrated genotype, gene expression, alternative splicing and DNA methylation profiles of up to 430 human kidneys to characterize the effects of BP index variants from genome-wide association studies (GWASs) on renal transcriptome and epigenome. We uncovered kidney targets for 479 (58.3%) BP-GWAS variants and paired 49 BP-GWAS kidney genes with 210 licensed drugs. Our colocalization and Mendelian randomization analyses identified 179 unique kidney genes with evidence of putatively causal effects on BP. Through Mendelian randomization, we also uncovered effects of BP on renal outcomes commonly affecting patients with hypertension. Collectively, our studies identified genetic variants, kidney genes, molecular mechanisms and biological pathways of key relevance to the genetic regulation of BP and inherited susceptibility to hypertension. © 2021, Crown.

2020 International Society of Hypertension global hypertension practice guidelines

- Unger, Thomas, Borghi, Claudio, Charchar, Fadi, Khan, Nadia, Poulter, Neil

2020 International Society of Hypertension global hypertension practice guidelines

- Unger, Thomas, Borghi, Claudio, Charchar, Fadi, Khan, Nadia, Poulter, Neil, Prabhakaran, Dorairaj, Ramirez, Agustin, Schlaich, Markus, Stergiou, George, Tomaszewski, Maciej, Wainford, Richard, Williams, Bryan, Schutte, Aletta

A guide to the short, long and circular RNAs in hypertension and cardiovascular disease

- Prestes, Priscilla, Maier, Michelle, Woods, Bradley, Charchar, Fadi

  • Authors: Prestes, Priscilla , Maier, Michelle , Woods, Bradley , Charchar, Fadi
  • Date: 2020
  • Type: Text , Journal article , Review
  • Relation: International Journal of Molecular Sciences Vol. 21, no. 10 (2020)
  • Full Text:
  • Reviewed:
  • Description: Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in adults in developed countries. CVD encompasses many diseased states, including hypertension, coronary artery disease and atherosclerosis. Studies in animal models and human studies have elucidated the contribution of many genetic factors, including non-coding RNAs. Non-coding RNAs are RNAs not translated into protein, involved in gene expression regulation post-transcriptionally and implicated in CVD. Of these, circular RNAs (circRNAs) and microRNAs are relevant. CircRNAs are created by the back-splicing of pre-messenger RNA and have been underexplored as contributors to CVD. These circRNAs may also act as biomarkers of human disease, as they can be extracted from whole blood, plasma, saliva and seminal fluid. CircRNAs have recently been implicated in various disease processes, including hypertension and other cardiovascular disease. This review article will explore the promising and emerging roles of circRNAs as potential biomarkers and therapeutic targets in CVD, in particular hypertension. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.

An improved 3-(4,5-dmethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl )-2H-tetrazolium proliferation assay to overcome the interference of hydralazine

- Wang, Yutang, Nguyen, Dinh, Yang, Guang, Anesi, Jack, Chai, Zhonglin, Charchar, Fadi, Golledge, Jonathan

  • Authors: Wang, Yutang , Nguyen, Dinh , Yang, Guang , Anesi, Jack , Chai, Zhonglin , Charchar, Fadi , Golledge, Jonathan
  • Date: 2020
  • Type: Text , Journal article
  • Relation: Assay and Drug Development Technologies Vol. 18, no. 8 (Dec 2020), p. 379-384
  • Relation: https://purl.org/au-research/grants/nhmrc/1062671
  • Full Text:
  • Reviewed:
  • Description: The MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] assay is one of the most commonly used assays to assess cell proliferation and cytotoxicity, but is subject to interference by testing compounds. Hydralazine, an antihypertensive drug, is commonly investigated in multiple fields such as heart failure, cancer, and blood pressure research. This study reported interference of the MTS assay by hydralazine and a simple modification overcoming this interference. Vascular smooth muscle cells were cultured in the presence or absence of hydralazine (0, 10, 50,100, and 500 mu M) for 2 or 24 h. Cell numbers were analyzed using MTS, trypan blue exclusion, or microscopic assays. A modified version of the standard MTS assay was established, in which an additional step was added replacing the test medium, containing hydralazine, with fresh culture medium immediately before the addition of the MTS reagent. Culture with hydralazine at concentrations of 50, 100, and 500 mu M for 2 h increased absorbance (p< 0.05) in the standard MTS assay, whereas microscopy suggested no change in cell numbers. Culture with 500 mu m hydralazine for 24 h increased absorbance (p< 0.05) in the standard MTS assay, however, trypan blue exclusion and microscopy suggested a decrease in cell numbers. In a cell-free system, hydralazine (>= 10 mu M) increased absorbance in a concentration-dependent manner. The modified MTS assay produced results consistent with trypan blue exclusion and microscopy. In conclusion, a simple modification of the standard MTS assay overcame the interference of hydralazine and may be useful to avoid interference from other tested compounds.

Discovery of rare variants associated with blood pressure regulation through meta-analysis of 1.3 million individuals

- Surendran, Praveen, Feofanova, Elena, Lahrouchi, Najim, Ntalla, Ionna, Karthikeyan, Savita, Cook, James, Chen, Lingyan, Mifsud, Borbala, Yao, Chen, Kraja, Aldi, Cartwright, James, Hellwege, Jacklyn, Giri, Ayush, Tragante, Vinicius, Thorleifsson, Gudmar, Liu, Dajiang, Prins, Bram, Stewart, Isobel, Cabrera, Claude, Eales, James, Akbarov, Artur, Auer, Paul, Charchar, Fadi, Howson, Joanna, LifeLines Cohort, Study, Epic, C. V. D., Epic InterAct, Understanding Society Scientific, Group, Million Veteran, Program

Highlights from the International Society of Hypertension's New Investigators Network during 2019

- Kruger, Ruan, Brunström, Mattias, Burger, Dylan, Charchar, Fadi, Climie, Rachel, Mirabito, Colafell, Kempny, Katrina, Korostovtseva, Lyudimila, Marques, Francine, Picone, Dean, Romero, Cesar, Steckelings, Ulrike, Velkoska, Elena, Wainford, Richard, Wynne, Brandi, Zanuzzi, Matias

Hypertension and renin-angiotensin system blockers are not associated with expression of angiotensin-converting enzyme 2 (ACE2) in the kidney

- Jiang, Xiao, Eales, James, Scannali, David, Prestes, Priscilla, Charchar, Fadi

  • Authors: Jiang, Xiao , Eales, James , Scannali, David , Prestes, Priscilla , Charchar, Fadi
  • Date: 2020
  • Type: Text , Journal article
  • Relation: European Heart Journal Vol. 41, no. 48 (2020), p. 4580-4588
  • Full Text:
  • Reviewed:
  • Description: Aims Angiotensin-converting enzyme 2 (ACE2) is the cellular entry point for severe acute respiratory syndrome coronavirus (SARS-CoV-2) - the cause of coronavirus disease 2019 (COVID-19). However, the effect of renin-angiotensin system (RAS)-inhibition on ACE2 expression in human tissues of key relevance to blood pressure regulation and COVID-19 infection has not previously been reported. Methods and results We examined how hypertension, its major metabolic co-phenotypes, and antihypertensive medications relate to ACE2 renal expression using information from up to 436 patients whose kidney transcriptomes were characterized by RNA-sequencing. We further validated some of the key observations in other human tissues and/or a controlled experimental model. Our data reveal increasing expression of ACE2 with age in both human lungs and the kidney. We show no association between renal expression of ACE2 and either hypertension or common types of RAS inhibiting drugs. We demonstrate that renal abundance of ACE2 is positively associated with a biochemical index of kidney function and show a strong enrichment for genes responsible for kidney health and disease in ACE2 coexpression analysis. Conclusion Our results indicate that neither hypertension nor antihypertensive treatment is likely to alter the expression of the key entry receptor for SARS-CoV-2 in the human kidney. Our data further suggest that in the absence of SARS-CoV-2 infection, kidney ACE2 is most likely nephro-protective but the age-related increase in its expression within lungs and kidneys may be relevant to the risk of SARS-CoV-2 infection. © The Author(s) 2020. *Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliates “James Eales", "Priscilla Prestes" and "Fadi Charchar” are provided in this record**

May measurement month 2019 the global blood pressure screening campaign of the International Society of Hypertension

- Beaney, Thomas, Schutte, Aletta, Stergiou, George, Borghi, Claudio, Burger, Dylan, Charchar, Fadi, Cro, Suzie, Diaz, Alejandro, Damasceno, Albertino, Espeche, Walter, Jose, Arun, Khan, Nadia, Kokubo, Yoshihiro, Maheshwari, Anuj, Marin, Marcos, More, Arun, Neupane, Dinesh, Nilsson, Peter, Patil, Mansi, Prabhakaran, Dorairaj, Ramirez, Agustin, Rodriguez, Pablo, Schlaich, Markus, Steckelings, Ulrike, Tomaszewski, Maciej, Unger, Thomas, Wainford, Richard, Wang, Jiguang, Williams, Bryan, Poulter, Neil, M. M. M. Investigators

Neural suppression of miRNA-181a in the kidney elevates renin expression and exacerbates hypertension in Schlager mice

- Jackson, Kristy, Gueguen, Cindy, Lim, Kyungjoon, Eikelis, Nina, Stevenson, Emily, Charchar, Fadi, Lambert, Gavin, Burke, Sandra, Paterson, Madeleine, Marques, Francine, Head, Geoffrey

  • Authors: Jackson, Kristy , Gueguen, Cindy , Lim, Kyungjoon , Eikelis, Nina , Stevenson, Emily , Charchar, Fadi , Lambert, Gavin , Burke, Sandra , Paterson, Madeleine , Marques, Francine , Head, Geoffrey
  • Date: 2020
  • Type: Text , Journal article
  • Relation: Hypertension Research Vol. 43, no. 11 (2020), p. 1152-1164
  • Full Text: false
  • Reviewed:
  • Description: BPH/2J mice are a genetic model of hypertension with overactivity of the sympathetic nervous system (SNS) and renin–angiotensin system (RAS). BPH/2J display higher renal renin mRNA and low levels of its negative regulator microRNA-181a (miR-181a). We hypothesise that high renal SNS activity may reduce miR-181a expression, which contributes to elevated RAS activity and hypertension in BPH/2J. Our aim was to determine whether in vivo administration of a renal-specific miR-181a mimic or whether renal denervation could increase renal miR-181a abundance to reduce renal renin mRNA, RAS activity and hypertension in BPH/2J mice. Blood pressure (BP) in BPH/2J and normotensive BPN/3J mice was measured via radiotelemetry probes. Mice were administered miR-181a mimic or a negative control (1–25 nmol, i.v., n = 6–10) with BP measured for 48 h after each dose or they underwent renal denervation or sham surgery (n = 7–9). Injection of 5–25 nmol miR-181a mimic reduced BP in BPH/2J mice after 36–48 h (−5.3 ± 1.8, −6.1 ± 1.9 mmHg, respectively, P < 0.016). Treatment resulted in lower renal renin and inflammatory marker (TLR4) mRNA levels in BPH/2J. The mimic abolished the hypotensive effect of blocking the RAS with enalaprilat (P < 0.01). No differences between mimic or vehicle were observed in BPN/3J mice except for a higher level of renal angiotensinogen in the mimic-treated mice. Renal miR-181a levels that were lower in sham BPH/2J mice were greater following renal denervation and were thus similar to those of BPN/3J. Our findings suggest that the reduced renal miR-181a may partially contribute to the elevated BP in BPH/2J mice, through an interaction between the renal sympathetic nerves and miR-181a regulation of the RAS. © 2020, The Japanese Society of Hypertension.
  • Description: This work was supported by a grant from the National Health & Medical Research Council of Australia (NHMRC, Project grant 1065714) and in part by the Victorian Government’s OIS Program. Investigators were supported by NHMRC/National Heart Foundation (NHF) Postdoctoral Fellowships (NHMRC APP1091688 to KLJ, NHMRC APP1052659 and NHF PF12M6785 and 101185 to FZM) and NHMRC Research Fellowships (APP1042492 to GWL and APP1002186 to GAH).