1
|
Reda A, Hategan LA, McLean TAB, Creighton SD, Luo JQ, Chen SES, Hua S, Winston S, Reeves I, Padmanabhan A, Dahi TA, Ramzan F, Brimble MA, Murphy PJ, Walters BJ, Stefanelli G, Zovkic IB. Role of the histone variant H2A.Z.1 in memory, transcription, and alternative splicing is mediated by lysine modification. Neuropsychopharmacology 2024:10.1038/s41386-024-01817-2. [PMID: 38366138 DOI: 10.1038/s41386-024-01817-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 01/30/2024] [Accepted: 02/01/2024] [Indexed: 02/18/2024]
Abstract
Creating long-lasting memories requires learning-induced changes in gene expression, which are impacted by epigenetic modifications of DNA and associated histone proteins. Post-translational modifications (PTMs) of histones are key regulators of transcription, with different PTMs producing unique effects on gene activity and behavior. Although recent studies implicate histone variants as novel regulators of memory, effects of PTMs on the function of histone variants are rarely considered. We previously showed that the histone variant H2A.Z suppresses memory, but it is unclear if this role is impacted by H2A.Z acetylation, a PTM that is typically associated with positive effects on transcription and memory. To answer this question, we used a mutation approach to manipulate acetylation on H2A.Z without impacting acetylation of other histone types. Specifically, we used adeno-associated virus (AAV) constructs to overexpress mutated H2A.Z.1 isoforms that either mimic acetylation (acetyl-mimic) by replacing lysines 4, 7 and 11 with glutamine (KQ), or H2A.Z.1 with impaired acetylation (acetyl-defective) by replacing the same lysines with alanine (KA). Expressing the H2A.Z.1 acetyl-mimic (H2A.Z.1KQ) improved memory under weak learning conditions, whereas expressing the acetyl-defective H2A.Z.1KA generally impaired memory, indicating that the effect of H2A.Z.1 on memory depends on its acetylation status. RNA sequencing showed that H2A.Z.1KQ and H2A.Z.1KA uniquely impact the expression of different classes of genes in both females and males. Specifically, H2A.Z.1KA preferentially impacts genes involved in synaptic function, suggesting that acetyl-defective H2A.Z.1 impairs memory by altering synaptic regulation. Finally, we describe, for the first time, that H2A.Z is also involved in alternative splicing of neuronal genes, whereby H2A.Z depletion, as well as expression of H2A.Z.1 lysine mutants influence transcription and splicing of different gene targets, suggesting that H2A.Z.1 can impact behavior through effects on both splicing and gene expression. This is the first study to demonstrate that direct manipulation of H2A.Z post-translational modifications regulates memory, whereby acetylation adds another regulatory layer by which histone variants can fine tune higher brain functions through effects on gene expression and splicing.
Collapse
Affiliation(s)
- Anas Reda
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON, M5S 3G3, Canada
| | - Luca A Hategan
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON, M5S 3G3, Canada
| | - Timothy A B McLean
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON, M5S 3G3, Canada
| | - Samantha D Creighton
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON, L5L 1C6, Canada
| | - Jian Qi Luo
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON, M5S 3G3, Canada
| | - Sean En Si Chen
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON, M5S 3G3, Canada
| | - Shan Hua
- Departments of Biology and Biomedical Genetics, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Stephen Winston
- Department of Surgery and Graduate school of Biomedical Sciences, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Isaiah Reeves
- Department of Surgery and Graduate school of Biomedical Sciences, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Aditya Padmanabhan
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON, L5L 1C6, Canada
| | - Tarkan A Dahi
- Department of Biology, University of Toronto Mississauga, Mississauga, ON, L5L 1C6, Canada
| | - Firyal Ramzan
- Department of Biology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - Mark A Brimble
- Department of Host-Microbe Interactions, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Patrick J Murphy
- Departments of Biology and Biomedical Genetics, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Brandon J Walters
- Department of Biology, University of Toronto Mississauga, Mississauga, ON, L5L 1C6, Canada
| | - Gilda Stefanelli
- Department of Biology, University of Ottawa, Ottawa, ON, K1N 6N5, Canada.
| | - Iva B Zovkic
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON, L5L 1C6, Canada.
| |
Collapse
|
2
|
Ramzan F, Abrar F, Mishra GG, Liao LMQ, Martin DDO. Lost in traffic: consequences of altered palmitoylation in neurodegeneration. Front Physiol 2023; 14:1166125. [PMID: 37324388 PMCID: PMC10268010 DOI: 10.3389/fphys.2023.1166125] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 05/12/2023] [Indexed: 06/17/2023] Open
Abstract
One of the first molecular events in neurodegenerative diseases, regardless of etiology, is protein mislocalization. Protein mislocalization in neurons is often linked to proteostasis deficiencies leading to the build-up of misfolded proteins and/or organelles that contributes to cellular toxicity and cell death. By understanding how proteins mislocalize in neurons, we can develop novel therapeutics that target the earliest stages of neurodegeneration. A critical mechanism regulating protein localization and proteostasis in neurons is the protein-lipid modification S-acylation, the reversible addition of fatty acids to cysteine residues. S-acylation is more commonly referred to as S-palmitoylation or simply palmitoylation, which is the addition of the 16-carbon fatty acid palmitate to proteins. Like phosphorylation, palmitoylation is highly dynamic and tightly regulated by writers (i.e., palmitoyl acyltransferases) and erasers (i.e., depalmitoylating enzymes). The hydrophobic fatty acid anchors proteins to membranes; thus, the reversibility allows proteins to be re-directed to and from membranes based on local signaling factors. This is particularly important in the nervous system, where axons (output projections) can be meters long. Any disturbance in protein trafficking can have dire consequences. Indeed, many proteins involved in neurodegenerative diseases are palmitoylated, and many more have been identified in palmitoyl-proteomic studies. It follows that palmitoyl acyl transferase enzymes have also been implicated in numerous diseases. In addition, palmitoylation can work in concert with cellular mechanisms, like autophagy, to affect cell health and protein modifications, such as acetylation, nitrosylation, and ubiquitination, to affect protein function and turnover. Limited studies have further revealed a sexually dimorphic pattern of protein palmitoylation. Therefore, palmitoylation can have wide-reaching consequences in neurodegenerative diseases.
Collapse
|
3
|
Alagaratnam J, Sabin CA, Garvey LJ, Ramzan F, Winston A, Fidler S, Mackie NE. Evaluating virological outcomes in people with HIV on stable antiretroviral therapy with reduced frequency of HIV viral load monitoring during the COVID-19 pandemic. HIV Med 2023. [PMID: 36895110 DOI: 10.1111/hiv.13474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 02/14/2023] [Indexed: 03/11/2023]
Abstract
OBJECTIVES In response to the COVID-19 pandemic, HIV outpatient attendances were restricted from March 2020, resulting in reduced frequency of HIV viral load (VL) monitoring (previously 6-monthly) in clinically stable and virologically suppressed people living with HIV (PLWH). We investigated virological outcomes during this period of reduced monitoring and compared with the previous year, prior to the COVID-19 pandemic. METHODS People living with HIV with undetectable VL (<200 HIV RNA copies /mL) on antiretroviral therapy (ART) were identified from March 2018 to February 2019. We determined VL outcomes during the pre-COVD-19 period (March 2019-February 2020) and the COVID-19 period (March 2020-February 2021) when monitoring was restricted. Frequency and longest durations between VL tests in each period were evaluated, and virological sequelae in those with detectable VL were determined. RESULTS Of 2677 PLWH virologically suppressed on ART (March 2018-February 2019), VLs were measured and undetectable in 2571 (96.0%) and 2003 (77.9%) in the pre-COVID and COVID periods, respectively. Mean (SD) numbers of VL tests were 2.3 (1.08) and 1.1 (0.83) and mean longest duration between VL tests was 29.5 weeks (SD 8.25, 3.1% were ≥12 months) and 43.7 weeks (12.64, 28.4% were ≥12 months), in the pre-COVID and COVID periods, respectively. Of 45 individuals with one or more detectable VL during the COVID-19 period, two developed new drug resistance mutations. CONCLUSION Reduced VL monitoring was not associated with poorer virological outcomes in the majority of stable individuals receiving ART. One in 20 individuals had not returned for VL testing after ≥31 months and the risk of harm in these individuals is unknown.
Collapse
Affiliation(s)
- J Alagaratnam
- Department of Genitourinary Medicine & HIV, St Mary's Hospital, Imperial College Healthcare NHS Trust, London, UK.,Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, UK
| | - C A Sabin
- Institute for Global Health, University College London, London, UK.,National Institute for Health and Care Research (NIHR) Health Protection Research Unit (HPRU) in Blood Borne and Sexually Transmitted Infections at UCL, UK
| | - L J Garvey
- Department of Genitourinary Medicine & HIV, St Mary's Hospital, Imperial College Healthcare NHS Trust, London, UK
| | - F Ramzan
- Department of Genitourinary Medicine & HIV, St Mary's Hospital, Imperial College Healthcare NHS Trust, London, UK
| | - A Winston
- Department of Genitourinary Medicine & HIV, St Mary's Hospital, Imperial College Healthcare NHS Trust, London, UK.,Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, UK
| | - S Fidler
- Department of Genitourinary Medicine & HIV, St Mary's Hospital, Imperial College Healthcare NHS Trust, London, UK.,Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, UK
| | - N E Mackie
- Department of Genitourinary Medicine & HIV, St Mary's Hospital, Imperial College Healthcare NHS Trust, London, UK
| |
Collapse
|
4
|
Phung T, Ramzan F, Monks DA. Hormone-dependent sexual responses of female mice in response to manual genital stimulation. Horm Behav 2023; 151:105338. [PMID: 36868148 DOI: 10.1016/j.yhbeh.2023.105338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 01/31/2023] [Accepted: 02/18/2023] [Indexed: 03/05/2023]
Abstract
Although copulatory behavior is thought to have a strong innate basis in mice, there is also clear evidence that sexual experience shapes its expression. Reinforcement of behavior through rewarding genital tactile stimulation is a primary candidate mechanism for this modification. In rats, manual tactile clitoral stimulation is rewarding only when it is temporally distributed, which is hypothesized to result from an innate preference for species-typical copulatory patterning. Here we test this hypothesis using mice, which have a temporal copulatory pattern which is distinctly less temporally distributed than that of rats. Female mice received manual clitoral stimulation which was either temporally continuous every second, or stimulation which was temporally distributed, occurring every 5 s, This pattern of stimulation was paired with environmental cues in a conditioned place preference apparatus to assess reward. Neural activation in response to this stimulation was evaluated by measuring FOS immunoreactivity. Results indicated that both temporal patterns of clitoral stimulation were rewarding, but that continuous stimulation better reproduced brain activation associated with sexual reward. Furthermore, continuous, but not distributed stimulation elicited a lordosis response in some females, and this response increased within and across days. Sexual reward, neural activation and lordosis resulting from tactile genital stimulation were eliminated by ovariectomy and restored with combined 17β-estradiol and progesterone treatment but not 17β-estradiol treatment alone. These observations are consistent with the hypothesis that sexual reward resulting from species-typical genital tactile stimulation has a permissive effect on copulatory behavior of female mice.
Collapse
Affiliation(s)
- Thanh Phung
- Department of Psychology, University of Toronto Mississauga, Canada; Department of Cell and Systems Biology, University of Toronto, Canada
| | - Firyal Ramzan
- Department of Psychology, University of Toronto Mississauga, Canada; Department of Biology, University of Waterloo, ON, Canada
| | - D Ashley Monks
- Department of Psychology, University of Toronto Mississauga, Canada; Department of Cell and Systems Biology, University of Toronto, Canada.
| |
Collapse
|
5
|
Ramzan F, Baumbach J, Monks AD, Zovkic IB. Histone H2A.Z is required for androgen receptor-mediated effects on fear memory. Neurobiol Learn Mem 2020; 175:107311. [PMID: 32916283 DOI: 10.1016/j.nlm.2020.107311] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 08/13/2020] [Accepted: 08/26/2020] [Indexed: 12/12/2022]
Abstract
Epigenetic factors translate environmental signals into stable outcomes, but how they are influenced by regulators of plasticity remain unclear. We previously showed that androgen receptor overexpression inhibited fear memory in male mice and increased expression of the histone variant H2A.Z, a novel epigenetic regulator of memory. Here, we used conditional-inducible H2A.Z knockout mice to investigate how H2A.Z deletion influences androgenic regulation of fear memory. We showed that conditional inducible H2A.Z deletion blocked memory-enhancing effects of androgen depletion (induced by gonadectomy), and of pharmacological inhibition of the androgen receptor with flutamide. Similarly, H2A.Z deletion blocked the memory-reducing effects of DHT, and DHT treatment in cultured hippocampal neurons altered H2A.Z binding, suggesting that AR is an H2A.Z regulator in neurons. Overall, these data show that fear memory formation is regulated by interactions between sex hormones and epigenetic factors, which has implications for sex differences in fear-related disorders.
Collapse
Affiliation(s)
- Firyal Ramzan
- University of Toronto Mississauga, Department of Psychology, Mississauga, Ontario L5L 1C6, Canada
| | - Jennet Baumbach
- University of Toronto Mississauga, Department of Psychology, Mississauga, Ontario L5L 1C6, Canada
| | - Ashley D Monks
- University of Toronto Mississauga, Department of Psychology, Mississauga, Ontario L5L 1C6, Canada
| | - Iva B Zovkic
- University of Toronto Mississauga, Department of Psychology, Mississauga, Ontario L5L 1C6, Canada.
| |
Collapse
|
6
|
Swift-Gallant A, Coome LA, Ramzan F, Monks DA. Non-androgenic testicular mediation of androphilia in male mice with global overexpression of androgen receptors. Behav Brain Res 2020; 391:112694. [PMID: 32428632 DOI: 10.1016/j.bbr.2020.112694] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 04/22/2020] [Accepted: 05/04/2020] [Indexed: 10/24/2022]
Abstract
Sexual attraction is robustly sexually differentiated among mammalian species. Gonadal androgens acting perinatally and in adulthood are required for male-typical preference for female sexual cues. Recent evidence suggests that at the high extent of AR signaling, male mice show an increased preference for same-sex odor cues. These findings were found only in mice that overexpress AR globally in all tissues (CMV-AR), whereas neural AR overexpression (Nestin-AR) did not affect sexual preference. The present studies investigated the endocrine basis of this phenotype and examined whether preference for male or female stimulus animals (partner preference) was also affected in these transgenic animals. We manipulated adult gonadal hormones in male mice that overexpress AR globally and males that overexpress AR only in neural tissue. We replicate the finding that androphilia is increased in gonadally intact CMV-AR males, and these males exhibited reduced neural activation in response to estrus female odors. Testosterone treatment of gonadectomized CMV-AR males was sufficient to induce a gynephilic olfactory preference, while a gynephilic partner preference was induced with gonadectomy alone. These findings suggest that altered sexual preference of CMV-AR male mice is mediated by inhibitory activational functions of the testes. Together, these results suggest that at the high extent of AR signaling, non-neural AR via the gonads, can promote androphilia.
Collapse
Affiliation(s)
- A Swift-Gallant
- Department of Psychology, Memorial University of Newfoundland, St. John's, NL, Canada
| | - L A Coome
- Department of Psychology, University of Toronto, Toronto, ON, Canada; Department of Psychology, University of Toronto Mississauga, Mississauga, ON, Canada
| | - F Ramzan
- Department of Psychology, University of Toronto, Toronto, ON, Canada; Department of Psychology, University of Toronto Mississauga, Mississauga, ON, Canada
| | - D A Monks
- Department of Psychology, University of Toronto, Toronto, ON, Canada; Department of Cells and Systems Biology, University of Toronto, Toronto, ON, Canada; Department of Psychology, University of Toronto Mississauga, Mississauga, ON, Canada.
| |
Collapse
|
7
|
Ramzan F, D'Souza RF, Durainayagam BR, Milan AM, Roy NC, Kruger MC, Henry CJ, Mitchell CJ, Cameron-Smith D. Inflexibility of the plasma miRNA response following a high-carbohydrate meal in overweight insulin-resistant women. Genes Nutr 2020; 15:2. [PMID: 32042348 PMCID: PMC7001289 DOI: 10.1186/s12263-020-0660-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 01/15/2020] [Indexed: 12/14/2022]
Abstract
Context Metabolic inflexibility is a characteristic of insulin resistance, limiting the ability to transiently regulate oxidative metabolism and gene expression in response to nutrient availability. Little is known of the flexibility of post-transcriptional regulation, including circulatory miRNAs (c-miRNAs). Design The abundances of targeted c-miRNAs, with reported functions in metabolic regulation, were analysed in response to a high-carbohydrate meal in healthy weight insulin-sensitive (IS) and overweight insulin-resistant (IR) women. Participants Age-matched healthy weight IS (n = 20, BMI = 24.3 ± 0.70) and overweight IR (n = 20, BMI = 28.6 ± 0.67) women. Methods An abundance of c-miRNAs was quantified prior to and following a high-carbohydrate breakfast meal (2500 kJ; 50% carbohydrate, 20% fat and 27% protein). Target genes of the differentially regulated c-miRNA were measured in RNA extracted from circulatory peripheral blood mononuclear cells (PBMCs). Results In healthy weight IS women, both miR-15a-5p (p = 0.03) and miR-17-5p (p < 0.01) levels were halved at 4 h post-meal. These miRNA remained unaltered following the same meal in the overweight IR women. Furthermore, amongst genes targeted by these miRNA, CPT1A (p = 0.01) and IL8 (p = 0.03) had also reduced expression 4 h post-meal only in the healthy weight IS women. Conclusions The study findings provide preliminary evidence for a possible extension of metabolic inflexibility to include c-miRNAs. Trial registration The clinical trial is registered with Australian New Zealand Clinical Trials Registry under Trial registration: ANZCTR: ACTRN12615001108505. Registered on 21 October 2015.
Collapse
Affiliation(s)
- F Ramzan
- 1The Liggins Institute, The University of Auckland, 85 Park Road, Grafton, Private Bag, 92019, Auckland, 1142 New Zealand.,2The Riddet Institute, Palmerston North, New Zealand
| | - R F D'Souza
- 1The Liggins Institute, The University of Auckland, 85 Park Road, Grafton, Private Bag, 92019, Auckland, 1142 New Zealand.,3School of Medical Sciences, The University of Auckland, Auckland, New Zealand
| | - B R Durainayagam
- 1The Liggins Institute, The University of Auckland, 85 Park Road, Grafton, Private Bag, 92019, Auckland, 1142 New Zealand
| | - A M Milan
- 1The Liggins Institute, The University of Auckland, 85 Park Road, Grafton, Private Bag, 92019, Auckland, 1142 New Zealand
| | - N C Roy
- 2The Riddet Institute, Palmerston North, New Zealand.,4Food Nutrition & Health Team, AgResearch Ltd, Palmerston North, New Zealand.,The High-Value Nutrition National Science Challenge, Auckland, New Zealand
| | - M C Kruger
- 6Institute of Food Science and Technology, Massey University, Palmerston North, New Zealand
| | - C J Henry
- 7Clinical Nutrition Research Centre, Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research, Singapore, 117609 Singapore
| | - C J Mitchell
- 1The Liggins Institute, The University of Auckland, 85 Park Road, Grafton, Private Bag, 92019, Auckland, 1142 New Zealand.,8School of Kinesiology, The University of British Columbia, Vancouver, Canada
| | - D Cameron-Smith
- 1The Liggins Institute, The University of Auckland, 85 Park Road, Grafton, Private Bag, 92019, Auckland, 1142 New Zealand.,2The Riddet Institute, Palmerston North, New Zealand.,9Food & Bio-Based Products Group, AgResearch Ltd, Palmerston North, New Zealand.,10Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research (ASTAR), Singapore, 117609 Singapore
| |
Collapse
|
8
|
Ramzan F, D'Souza RF, Durainayagam BR, Milan AM, Markworth JF, Miranda-Soberanis V, Sequeira IR, Roy NC, Poppitt SD, Mitchell CJ, Cameron-Smith D. Circulatory miRNA biomarkers of metabolic syndrome. Acta Diabetol 2020; 57:203-214. [PMID: 31435783 DOI: 10.1007/s00592-019-01406-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 08/08/2019] [Indexed: 12/19/2022]
Abstract
AIMS Circulatory microRNAs (c-miRNAs) exert important roles in the molecular dysregulation of cardio-metabolic diseases. However, little is known whether dysregulated miRNA expression occurs when risk factors are elevated, as in the metabolic syndrome (MetS). This study quantified c-miRNA expression in individuals with MetS compared to healthy, further examining the relationship of gene pathways with the underlying pathogenesis. METHODS Expression of 26 miRNAs was quantified in plasma from 40 women (20 healthy and 20 MetS) and 39 men (20 healthy and 19 MetS) by qPCR. In silico analysis was performed to investigate biological effects of the dysregulated miRNAs. Dysregulated miRNA expression was further validated in an independent cohort of 20 women (10 healthy and 10 MetS). RESULTS Regression model adjusted for age and sex identified miR-15a-5p, miR-17-5p, miR-370-3p and miR-375 as important predictors of MetS presence. Analysis of predictive miRNAs in the validation cohort strengthened the relationship with miR-15a-5p and miR-17-5p expression. These miRNAs share genes involved in the regulation of metabolic pathways including insulin, wnt, fatty acid metabolism and AMPK. CONCLUSIONS miR-15a-5p and miR-17-5p were identified as predictive biomarkers of MetS, irrespective of sexes, further demonstrating the relationship of c-miRNAs to known pathways of metabolic disturbances present in cardio-metabolic diseases.
Collapse
Affiliation(s)
- F Ramzan
- Liggins Institute, The University of Auckland, 85 Park Road, Grafton, Private Bag 92019, Auckland, 1142, New Zealand
- The Riddet Institute, Massey University, Palmerston North, New Zealand
| | - R F D'Souza
- Liggins Institute, The University of Auckland, 85 Park Road, Grafton, Private Bag 92019, Auckland, 1142, New Zealand
| | - B R Durainayagam
- Liggins Institute, The University of Auckland, 85 Park Road, Grafton, Private Bag 92019, Auckland, 1142, New Zealand
| | - A M Milan
- Liggins Institute, The University of Auckland, 85 Park Road, Grafton, Private Bag 92019, Auckland, 1142, New Zealand
| | - J F Markworth
- Liggins Institute, The University of Auckland, 85 Park Road, Grafton, Private Bag 92019, Auckland, 1142, New Zealand
| | | | - I R Sequeira
- The High-Value Nutrition National Science Challenge, Auckland, New Zealand
- Human Nutrition Unit, Department of Medicine, School of Biological Sciences, The University of Auckland, Auckland, New Zealand
| | - N C Roy
- Food Nutrition and Health Team, AgResearch Grasslands, Palmerston North, New Zealand
- The Riddet Institute, Massey University, Palmerston North, New Zealand
- The High-Value Nutrition National Science Challenge, Auckland, New Zealand
- Food and Bio-Based Products Group, AgResearch Ltd., Palmerston North, New Zealand
| | - S D Poppitt
- The Riddet Institute, Massey University, Palmerston North, New Zealand
- The High-Value Nutrition National Science Challenge, Auckland, New Zealand
- Human Nutrition Unit, Department of Medicine, School of Biological Sciences, The University of Auckland, Auckland, New Zealand
| | - C J Mitchell
- Liggins Institute, The University of Auckland, 85 Park Road, Grafton, Private Bag 92019, Auckland, 1142, New Zealand
- School of Kinesiology, The University of British Columbia, Vancouver, Canada
| | - D Cameron-Smith
- Liggins Institute, The University of Auckland, 85 Park Road, Grafton, Private Bag 92019, Auckland, 1142, New Zealand.
- The Riddet Institute, Massey University, Palmerston North, New Zealand.
- Food and Bio-Based Products Group, AgResearch Ltd., Palmerston North, New Zealand.
| |
Collapse
|
9
|
Francis-Morris A, Mackie NE, Eliahoo J, Ramzan F, Fidler S, Pollock KM. Compromised CD4:CD8 ratio recovery in people living with HIV aged over 50 years: an observational study. HIV Med 2019; 21:109-118. [PMID: 31617962 PMCID: PMC7003811 DOI: 10.1111/hiv.12800] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/05/2019] [Indexed: 11/28/2022]
Abstract
OBJECTIVES Persistent CD4:CD8 ratio inversion (< 1) is associated with mortality in older people. We investigated the interaction of the effects of baseline CD8 count and age at HIV diagnosis on CD4:CD8 ratio recovery with antiretroviral therapy (ART). METHODS An observational study (1 January 2007 to 31 December 2016) was carried out using routinely collected data from the HIV outpatient services at Imperial College Healthcare NHS Trust, London, UK. CD4 and CD8 counts, prior to and during ART, treatment during primary HIV infection (PHI) and HIV-1 viral load were included in univariate and multivariate analyses using Cox proportional hazard regression. RESULTS Data were included for 876 patients starting ART, where HIV suppression was achieved. Of these patients, 741 of 876 (84.6%) were male and 507 of 876 (57.9%) were Caucasian. The median time on ART was 38 [interquartile range (IQR) 17-66] months. CD8 count change on ART was bidirectional; low CD8 counts (≤ 600 cells/μL) increased and high CD8 counts (> 900 cells/μL) decreased. The median pre-ART CD4:CD8 ratio was 0.41 (IQR 0.24-0.63), and recovery (≥ 1) occurred in 274 of 876 patients (31.3%). Pre- and post-ART CD4:CD8 ratios were lower in those aged > 50 years compared with young adults aged 18-30 years (P < 0.001 and P = 0.002, respectively). After adjustment, younger age at HIV diagnosis (P < 0.001) and treatment during PHI (P < 0.001) were favourable for CD4:CD8 ratio normalization. CONCLUSIONS Older age (> 50 years) at HIV diagnosis was associated with persistent CD4:CD8 ratio inversion, whereas treatment of PHI was protective. These findings confirm the need for testing and early treatment of people aged > 50 years, and could be used in a risk management algorithm for enhanced surveillance.
Collapse
Affiliation(s)
- A Francis-Morris
- Section of Virology, Department of Infectious Disease, Imperial College London, London, UK
| | - N E Mackie
- Jefferiss Wing, Imperial College Healthcare NHS Trust, London, UK
| | - J Eliahoo
- Statistical Advisory Service, Imperial College London, London, UK
| | - F Ramzan
- Jefferiss Wing, Imperial College Healthcare NHS Trust, London, UK
| | - S Fidler
- Section of Virology, Department of Infectious Disease, Imperial College London, London, UK.,National Institute for Health Research Imperial Biomedical Research Centre, London, UK
| | - K M Pollock
- Section of Virology, Department of Infectious Disease, Imperial College London, London, UK.,Jefferiss Wing, Imperial College Healthcare NHS Trust, London, UK.,National Institute for Health Research Imperial Biomedical Research Centre, London, UK
| |
Collapse
|
10
|
Ramzan F, Phung T, Swift-Gallant A, Coome LA, Holmes MM, Monks DA. Both neural and global androgen receptor overexpression affect sexual dimorphism in the mouse brain. J Neuroendocrinol 2019; 31:e12715. [PMID: 30920021 DOI: 10.1111/jne.12715] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 03/14/2019] [Accepted: 03/22/2019] [Indexed: 01/28/2023]
Abstract
Testosterone is the main endocrine mechanism mediating sexual differentiation of the mammalian brain, although testosterone signalling is complex and important mechanistic questions remain. Notably, the extent to which testosterone acts via androgen receptors (AR) in this process remains unknown and it is also not clear where testosterone acts in the body to produce sexual dimorphisms in neuroanatomy. To address these questions, we used a transgenic mouse model of Cre/loxP-driven AR overexpression in which AR was induced selectively in neural tissue (Nestin-cre) or in all tissues (CMV-cre). We then studied sexually dimorphic features of several well-characterised sexual dimorphisms: calbindin-immunoreactive neurones in the medial preoptic area (CALB-SDN), tyrosine hydroxylase neurones in the anteroventral periventricular nucleus, and vasopressin-immunoreactive neurones originating in the bed nucleus of the stria terminalis and their projections in the lateral septum. We additionally evaluated oestrogen receptor α immunoreactivity in these nuclei. Briefly, we found that global but not neural overexpression of AR resulted in masculinisation of CALB-SDN nucleus volume, cell number and cell size in transgenic females. Furthermore, neural AR overexpression resulted in increased oestrogen receptor α staining in females compared to males in the medial preoptic area. AR overexpression did not affect other measures. Overall, the results of the present study provide support for the hypothesis that androgenic mechanisms external to the nervous system can affect sexual differentiation of the brain.
Collapse
Affiliation(s)
- Firyal Ramzan
- Department of Psychology, University of Toronto Mississauga, Mississauga, Ontario, Canada
| | - Thanh Phung
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Ashlyn Swift-Gallant
- Department of Psychology, University of Toronto Mississauga, Mississauga, Ontario, Canada
- Department of Psychology, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Lindsay A Coome
- Department of Psychology, University of Toronto Mississauga, Mississauga, Ontario, Canada
| | - Melissa M Holmes
- Department of Psychology, University of Toronto Mississauga, Mississauga, Ontario, Canada
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - D Ashley Monks
- Department of Psychology, University of Toronto Mississauga, Mississauga, Ontario, Canada
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
11
|
Blandy O, Honeyford K, Gharbi M, Thomas A, Ramzan F, Ellington M, Hope R, Holmes A, Johnson A, Aylin P, Woodford N, Sriskandan S. Factors that impact on the burden of Escherichia coli bacteraemia: multivariable regression analysis of 2011–2015 data from West London. J Hosp Infect 2019; 101:120-128. [DOI: 10.1016/j.jhin.2018.10.024] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 10/30/2018] [Indexed: 11/24/2022]
|
12
|
Zeng N, Prodhan U, D'Souza RF, Ramzan F, Mitchell SM, Sharma P, Knowles SO, Roy NC, Sjödin A, Wagner KH, Milan AM, Cameron-Smith D, Mitchell CJ. Regulation of Amino Acid Transporters and Sensors in Response to a High protein Diet: A Randomized Controlled Trial in Elderly Men. J Nutr Health Aging 2019; 23:354-363. [PMID: 30932134 DOI: 10.1007/s12603-019-1171-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND The mammalian target of rapamycin complex 1 (mTORC1) is fundamental for many cellular processes, yet it is often dysregulated with aging. Increased amino acid (AA) availability is correlated with the expression of AA transporters (AAT) and mTORC1 activity. Although many AA sensors and mediators have been proposed to relay the AA signal to mTORC1, it has not yet been determined if chronic dietary intervention affects the expression of AAT, sensors and mediators and their relationships with mTORC1 activity. OBJECTIVE AND DESIGN This study investigated whether the consumption of a diet containing either the current recommended daily allowance (RDA) of protein intake (0.8 g/kg/d) or twice the RDA (2RDA) for ten weeks affected the expression of targets associated with AA transport, sensing and mTORC1 regulation in 26 older men (70-81 years). METHOD Muscle biopsies were collected before and after the intervention under fasting conditions. Diets were controlled by providing fully prepared meals and snacks. Western blot and quantitative polymerase chain reaction were used to measure protein and gene expression respectively. RESULTS Consumption of 2RDA reduced the protein expression of L-type amino acid transporter 1 (LAT1). However, plasma leucine concentration and basal mTORC1 activity were unaltered. The downregulation of LAT1 did not affect the expression of AA sensors and mediators, including leucyl tRNA synthetase (LRS), cytosolic arginine sensor for mTORC1 (CASTOR1), Sestrin2 and Rag proteins. Instead, total ribosomal protein S6 (RPS6) was upregulated with 2RDA. CONCLUSION Ten weeks of 2RDA diet did not affect the fasting mTORC1 signaling, but increased total RPS6 might suggest improved muscular translational capacity to maintain muscular mass.
Collapse
Affiliation(s)
- N Zeng
- Dr. Cameron Mitchell Faculty of Education | School of Kinesiology, The University of British Columbia | Vancouver Campus, 2553 Wesbrook Mall | Vancouver British Columbia | V6T 1Z3 Canada, Phone 604 827 2072| Cell 604 790 3815,
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Ramzan F, Azam AB, Monks DA, Zovkic IB. Androgen receptor is a negative regulator of contextual fear memory in male mice. Horm Behav 2018; 106:10-18. [PMID: 30172646 DOI: 10.1016/j.yhbeh.2018.08.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Revised: 08/21/2018] [Accepted: 08/29/2018] [Indexed: 10/28/2022]
Abstract
Although sex-hormones have a well-documented role in memory formation, most literature has focused on estrogens, whereas the role of androgens and their receptor (the androgen receptor; AR) in fear memory is relatively unexplored. To address this gap, we used a transgenic mouse model of AR overexpression (CMV-AR) to determine if AR regulates fear memory, and if this effect can be reversed either by the removal of circulating androgens via gonadectomy, or by antagonising AR activity with flutamide. We found that AR overexpression results in reduced freezing in response to foot shock, and that this difference is reversed with both gonadectomy and flutamide treatment. Differences between genotypes were reinstated by testosterone replacement in gonadectomized mice, suggesting that reduced fear memory in mutants results from AR activation by testosterone and is not secondary to group differences in circulating testosterone. Potential transcriptional mechanisms by which CMV-AR exerts its effects on fear memory were assessed by quantitating the expression of memory-related genes in area CA1 of the hippocampus. Several genes that are altered with AR inhibition and activation, including genes that encode for the histone variant H2A.Z, cholinergic receptors, glutamate receptors, and brain-derived neurotrophic factor. Overall, our findings suggest that AR is a negative regulator of fear memory and identify potential gene targets through which AR may mediate this effect.
Collapse
Affiliation(s)
- Firyal Ramzan
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON, Canada
| | - Amber B Azam
- Department of Cell and Systems Biology, University of Toronto Mississauga, Mississauga, ON, Canada
| | - D Ashley Monks
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON, Canada; Department of Cell and Systems Biology, University of Toronto Mississauga, Mississauga, ON, Canada
| | - Iva B Zovkic
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON, Canada.
| |
Collapse
|
14
|
Coome LA, Swift-Gallant A, Ramzan F, Melhuish Beaupre L, Brkic T, Monks DA. Neural androgen receptor overexpression affects cell number in the spinal nucleus of the bulbocavernosus. J Neuroendocrinol 2017; 29. [PMID: 28833628 DOI: 10.1111/jne.12515] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 07/25/2017] [Accepted: 08/15/2017] [Indexed: 12/27/2022]
Abstract
The spinal nucleus of the bulbocavernosus (SNB) is a sexually dimorphic neuromuscular system in which the masculinisation of cell number is assumed to depend on the action of perinatal androgen in non-neural targets, whereas the masculinisation of cell size is assumed to depend primarily on the action of adult androgen on SNB cells themselves. To test these hypotheses, we characterised the SNB of Cre/loxP transgenic mice that overexpress androgen receptor (AR) throughout the body (CMV-AR) or in neural tissue only (Nestin-AR). Additionally, we examined the effects of androgen manipulation in male mutants and wild-type (WT) controls. We reproduced the expected sex differences in both motoneurone number and size, as well as the expected adult androgen dependence of SNB size. We found effects of genotype such that both Nestin-AR and CMV-AR have more SNB motoneurones than WT littermates and also that CMV-AR females have larger SNB motoneurones than Nes-AR or WT females. These results raise the possibility that AR can act in neurones and/or glia to rescue SNB motoneurones, as well as on non-neural AR to increase SNB cell size.
Collapse
Affiliation(s)
- L A Coome
- Psychology, University of Toronto Mississauga, Mississauga, ON, Canada
| | - A Swift-Gallant
- Psychology, University of Toronto Mississauga, Mississauga, ON, Canada
| | - F Ramzan
- Psychology, University of Toronto Mississauga, Mississauga, ON, Canada
| | | | - T Brkic
- Psychology, University of Toronto Mississauga, Mississauga, ON, Canada
| | - D A Monks
- Psychology, University of Toronto Mississauga, Mississauga, ON, Canada
- Cells and Systems Biology, University of Toronto, Toronto, ON, Canada
| |
Collapse
|
15
|
Abstract
OBJECTIVE Urgent care centres' (UCCs) hours were developed with the aim of reducing inappropriate emergency department (ED) attendances in England. We aimed to examine the presenting complaint and outcomes of care in 2 general practitioner (GP)-led UCCs with extended opening times. DESIGN Retrospective observational epidemiological study using routinely collected data. SETTING 2 GP-led UCCs in London, colocated with a hospital ED. PARTICIPANTS All children aged under 5 years, attending 2 GP-led UCCs over a 3-year period. OUTCOMES Outcomes of care for the children including: primary diagnosis; registration status with a GP; destination following review within the UCC; and any medication prescribed. Comparison between GP-led UCC visit rates and routine general practices was also made. RESULTS 3% (n=7747/282 947) of all attenders at the GP-led UCCs were children aged under 5 years. The most common reason for attendance was a respiratory illness (27%), followed by infectious illness (17%). 18% (n=1428) were either upper respiratory tract infections or viral infections. The majority (91%) of children attending were registered with a GP, and over two-thirds of attendances were 'out of hours'. Overall 79% were seen and discharged home. Preschool children were more likely to attend their GP (47.0 per 100) than a GP-led UCC (9.4 per 100; 95% CI 8.9 to 10.0). CONCLUSIONS Two-thirds of preschool children attending GP-led UCCs do so out of hours, despite the majority being registered with a GP. The case mix is comparable with those presenting to an ED setting, with the majority managed exclusively by the GPs in the UCC before discharge home. Further work is required to understand the benefits of a GP-led urgent system in influencing future use of services especially emergency care.
Collapse
Affiliation(s)
- S Gnani
- Department of Primary Care and Public Health, Imperial College London, London, UK
| | - S Morton
- Department of Primary Care and Public Health, Imperial College London, London, UK
| | - F Ramzan
- Department of Primary Care and Public Health, Imperial College London, London, UK
| | - M Davison
- North End Medical Centre, London, UK
| | - T Ladbrooke
- London Central and West Unscheduled Care Collaborative, London, UK
| | - A Majeed
- Department of Primary Care and Public Health, Imperial College London, London, UK
| | - S Saxena
- Department of Primary Care and Public Health, Imperial College London, London, UK
| |
Collapse
|
16
|
Abstract
Testosterone, acting via estrogenic and androgenic pathways, is the major endocrine mechanism promoting sexual differentiation of the mammalian nervous system and behavior, but we have an incomplete knowledge of which cells and tissues mediate these effects. To distinguish between neural and nonneural actions of androgens in sexual differentiation of brain and behavior, we generated a loxP-based transgenic mouse, which overexpresses androgen receptors (ARs) when activated by Cre. We used this transgene to overexpress AR globally in all tissues using a cytomegalovirus (CMV)-Cre driver (CMV-AR), and we used a Nestin-Cre driver to overexpress AR only in neural tissue (Nes-AR). We then examined whether neural or global AR overexpression can affect socio-sexual behaviors using a resident-intruder paradigm. We found that both neural and global AR overexpression resulted in decreased aggressive behaviors and increased thrusting during mounting of intruders, consistent with a neural site of action. Global, but not neural, AR overexpression in males led to an increase in same-sex anogenital investigation. Together, these results suggest novel roles for nonneural AR in sexual differentiation of mice, and indicate that excess AR can lead to a paradoxical reduction of male-typical behavior.
Collapse
Affiliation(s)
- Ashlyn Swift-Gallant
- Departments of Psychology (A.S.-G., L.A.C., F.R., D.A.M.), Neuroscience (L.A.C., F.R., D.A.M.), and Cells and Systems Biology (D.A.M.), University of Toronto, Toronto, Ontario, Canada M5S 3G3; and Department of Psychology (A.S.-G., L.A.C., F.R., D.A.M.), University of Toronto, Mississauga, Mississauga, Ontario, Canada L5L 1C6
| | - Lindsay A Coome
- Departments of Psychology (A.S.-G., L.A.C., F.R., D.A.M.), Neuroscience (L.A.C., F.R., D.A.M.), and Cells and Systems Biology (D.A.M.), University of Toronto, Toronto, Ontario, Canada M5S 3G3; and Department of Psychology (A.S.-G., L.A.C., F.R., D.A.M.), University of Toronto, Mississauga, Mississauga, Ontario, Canada L5L 1C6
| | - Firyal Ramzan
- Departments of Psychology (A.S.-G., L.A.C., F.R., D.A.M.), Neuroscience (L.A.C., F.R., D.A.M.), and Cells and Systems Biology (D.A.M.), University of Toronto, Toronto, Ontario, Canada M5S 3G3; and Department of Psychology (A.S.-G., L.A.C., F.R., D.A.M.), University of Toronto, Mississauga, Mississauga, Ontario, Canada L5L 1C6
| | - D Ashley Monks
- Departments of Psychology (A.S.-G., L.A.C., F.R., D.A.M.), Neuroscience (L.A.C., F.R., D.A.M.), and Cells and Systems Biology (D.A.M.), University of Toronto, Toronto, Ontario, Canada M5S 3G3; and Department of Psychology (A.S.-G., L.A.C., F.R., D.A.M.), University of Toronto, Mississauga, Mississauga, Ontario, Canada L5L 1C6
| |
Collapse
|
17
|
Amiel C, Williams B, Ramzan F, Islam S, Ladbrooke T, Majeed A, Gnani S. Reasons for attending an urban urgent care centre with minor illness: a questionnaire study. Emerg Med J 2014; 31:e71-5. [DOI: 10.1136/emermed-2012-202016] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|