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King NE, Courtney JM, Brown LS, Fortune AJ, Blackburn NB, Fletcher JL, Cashion JM, Talbot J, Pébay A, Hewitt AW, Morris GP, Young KM, Cook AL, Sutherland BA. Induced pluripotent stem cell derived pericytes respond to mediators of proliferation and contractility. Stem Cell Res Ther 2024; 15:59. [PMID: 38433209 PMCID: PMC10910734 DOI: 10.1186/s13287-024-03671-x] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 02/16/2024] [Indexed: 03/05/2024] Open
Abstract
BACKGROUND Pericytes are multifunctional contractile cells that reside on capillaries. Pericytes are critical regulators of cerebral blood flow and blood-brain barrier function, and pericyte dysfunction may contribute to the pathophysiology of human neurological diseases including Alzheimers disease, multiple sclerosis, and stroke. Induced pluripotent stem cell (iPSC)-derived pericytes (iPericytes) are a promising tool for vascular research. However, it is unclear how iPericytes functionally compare to primary human brain vascular pericytes (HBVPs). METHODS We differentiated iPSCs into iPericytes of either the mesoderm or neural crest lineage using established protocols. We compared iPericyte and HBVP morphologies, quantified gene expression by qPCR and bulk RNA sequencing, and visualised pericyte protein markers by immunocytochemistry. To determine whether the gene expression of neural crest iPericytes, mesoderm iPericytes or HBVPs correlated with their functional characteristics in vitro, we quantified EdU incorporation following exposure to the key pericyte mitogen, platelet derived growth factor (PDGF)-BB and, contraction and relaxation in response to the vasoconstrictor endothelin-1 or vasodilator adenosine, respectively. RESULTS iPericytes were morphologically similar to HBVPs and expressed canonical pericyte markers. However, iPericytes had 1864 differentially expressed genes compared to HBVPs, while there were 797 genes differentially expressed between neural crest and mesoderm iPericytes. Consistent with the ability of HBVPs to respond to PDGF-BB signalling, PDGF-BB enhanced and a PDGF receptor-beta inhibitor impaired iPericyte proliferation. Administration of endothelin-1 led to iPericyte contraction and adenosine led to iPericyte relaxation, of a magnitude similar to the response evoked in HBVPs. We determined that neural crest iPericytes were less susceptible to PDGFR beta inhibition, but responded most robustly to vasoconstrictive mediators. CONCLUSIONS iPericytes express pericyte-associated genes and proteins and, exhibit an appropriate physiological response upon exposure to a key endogenous mitogen or vasoactive mediators. Therefore, the generation of functional iPericytes would be suitable for use in future investigations exploring pericyte function or dysfunction in neurological diseases.
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Affiliation(s)
- Natalie E King
- Tasmanian School of Medicine, College of Health and Medicine, University of Tasmania, Level 4, Medical Sciences Precinct, 17 Liverpool St, Hobart, TAS, 7000, Australia
| | - Jo-Maree Courtney
- Tasmanian School of Medicine, College of Health and Medicine, University of Tasmania, Level 4, Medical Sciences Precinct, 17 Liverpool St, Hobart, TAS, 7000, Australia
| | - Lachlan S Brown
- Tasmanian School of Medicine, College of Health and Medicine, University of Tasmania, Level 4, Medical Sciences Precinct, 17 Liverpool St, Hobart, TAS, 7000, Australia
| | - Alastair J Fortune
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Nicholas B Blackburn
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Jessica L Fletcher
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Jake M Cashion
- Tasmanian School of Medicine, College of Health and Medicine, University of Tasmania, Level 4, Medical Sciences Precinct, 17 Liverpool St, Hobart, TAS, 7000, Australia
| | - Jana Talbot
- Wicking Dementia Education and Research Centre, College of Health and Medicine, University of Tasmania, Hobart, Australia
| | - Alice Pébay
- Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Australia
- Department of Surgery, Royal Melbourne Hospital, The University of Melbourne, Melbourne, Australia
| | - Alex W Hewitt
- Tasmanian School of Medicine, College of Health and Medicine, University of Tasmania, Level 4, Medical Sciences Precinct, 17 Liverpool St, Hobart, TAS, 7000, Australia
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
- Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Australia
- Department of Surgery, Royal Melbourne Hospital, The University of Melbourne, Melbourne, Australia
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia
| | - Gary P Morris
- Tasmanian School of Medicine, College of Health and Medicine, University of Tasmania, Level 4, Medical Sciences Precinct, 17 Liverpool St, Hobart, TAS, 7000, Australia
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Anthony L Cook
- Wicking Dementia Education and Research Centre, College of Health and Medicine, University of Tasmania, Hobart, Australia
| | - Brad A Sutherland
- Tasmanian School of Medicine, College of Health and Medicine, University of Tasmania, Level 4, Medical Sciences Precinct, 17 Liverpool St, Hobart, TAS, 7000, Australia.
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Reale LA, Dyer MS, Perry SE, Young KM, Dickson TC, Woodhouse A, Blizzard CA. Pathologically mislocalised TDP-43 in upper motor neurons causes a die-forward spread of ALS-like pathogenic changes throughout the mouse corticomotor system. Prog Neurobiol 2023; 226:102449. [PMID: 37011806 DOI: 10.1016/j.pneurobio.2023.102449] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 02/02/2023] [Accepted: 03/24/2023] [Indexed: 04/03/2023]
Abstract
Alterations in upper motor neuron excitability are one of the earliest phenomena clinically detected in ALS, and in 97% of cases, the RNA/DNA binding protein, TDP-43, is mislocalised in upper and lower motor neurons. While these are two major pathological hallmarks in disease, our understanding of where disease pathology begins, and how it spreads through the corticomotor system, is incomplete. This project used a model where mislocalised TDP-43 was expressed in the motor cortex, to determine if localised cortical pathology could result in widespread corticomotor system degeneration. Mislocalised TDP-43 caused layer V excitatory neurons in the motor cortex to become hyperexcitable after 20 days of expression. Following cortical hyperexcitability, a spread of pathogenic changes through the corticomotor system was observed. By 30 days expression, there was a significant decrease in lower motor neuron number in the lumbar spinal cord. However, cell loss occurred selectively, with a significant loss in lumbar regions 1-3, and not lumbar regions 4-6. This regional vulnerability was associated with alterations in pre-synaptic excitatory and inhibitory proteins. Excitatory inputs (VGluT2) were increased in all lumbar regions, while inhibitory inputs (GAD65/67) were increased in lumbar regions 4-6 only. This data indicates that mislocalised TDP-43 in upper motor neurons can cause lower motor neuron degeneration. Furthermore, cortical pathology increased excitatory inputs to the spinal cord, to which local circuitry compensated with an upregulation of inhibition. These findings reveal how TDP-43 mediated pathology may spread through corticofugal tracts in ALS and identify a potential pathway for therapeutic intervention.
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Cashion JM, Young KM, Sutherland BA. How does neurovascular unit dysfunction contribute to multiple sclerosis? Neurobiol Dis 2023; 178:106028. [PMID: 36736923 DOI: 10.1016/j.nbd.2023.106028] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [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: 07/06/2022] [Revised: 01/17/2023] [Accepted: 01/30/2023] [Indexed: 02/04/2023] Open
Abstract
Multiple sclerosis is an inflammatory demyelinating disease of the central nervous system (CNS) and the most common non-traumatic cause of neurological disability in young adults. Multiple sclerosis clinical care has improved considerably due to the development of disease-modifying therapies that effectively modulate the peripheral immune response and reduce relapse frequency. However, current treatments do not prevent neurodegeneration and disease progression, and efforts to prevent multiple sclerosis will be hampered so long as the cause of this disease remains unknown. Risk factors for multiple sclerosis development or severity include vitamin D deficiency, cigarette smoking and youth obesity, which also impact vascular health. People with multiple sclerosis frequently experience blood-brain barrier breakdown, microbleeds, reduced cerebral blood flow and diminished neurovascular reactivity, and it is possible that these vascular pathologies are tied to multiple sclerosis development. The neurovascular unit is a cellular network that controls neuroinflammation, maintains blood-brain barrier integrity, and tightly regulates cerebral blood flow, matching energy supply to neuronal demand. The neurovascular unit is composed of vessel-associated cells such as endothelial cells, pericytes and astrocytes, however neuronal and other glial cell types also comprise the neurovascular niche. Recent single-cell transcriptomics data, indicate that neurovascular cells, particular cells of the microvasculature, are compromised within multiple sclerosis lesions. Large-scale genetic and small-scale cell biology studies also suggest that neurovascular dysfunction could be a primary pathology contributing to multiple sclerosis development. Herein we revisit multiple sclerosis risk factors and multiple sclerosis pathophysiology and highlight the known and potential roles of neurovascular unit dysfunction in multiple sclerosis development and disease progression. We also evaluate the suitability of the neurovascular unit as a potential target for future disease modifying therapies for multiple sclerosis.
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Affiliation(s)
- Jake M Cashion
- Tasmanian School of Medicine, College of Health and Medicine, University of Tasmania, Hobart, Tasmania, Australia
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania 7000, Australia
| | - Brad A Sutherland
- Tasmanian School of Medicine, College of Health and Medicine, University of Tasmania, Hobart, Tasmania, Australia.
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4
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Makowiecki K, Stevens N, Cullen CL, Zarghami A, Nguyen PT, Johnson L, Rodger J, Hinder MR, Barnett M, Young KM, Taylor BV. Safety of low-intensity repetitive transcranial magneTic brAin stimUlation foR people living with mUltiple Sclerosis (TAURUS): study protocol for a randomised controlled trial. Trials 2022; 23:626. [PMID: 35922816 PMCID: PMC9347125 DOI: 10.1186/s13063-022-06526-z] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 07/06/2022] [Indexed: 11/30/2022] Open
Abstract
Background Multiple sclerosis (MS) is an inflammatory and neurodegenerative disease, characterised by oligodendrocyte death and demyelination. Oligodendrocyte progenitor cells can differentiate into new replacement oligodendrocytes; however, remyelination is insufficient to protect neurons from degeneration in people with MS. We previously reported that 4 weeks of daily low-intensity repetitive transcranial magnetic stimulation (rTMS) in an intermittent theta-burst stimulation (iTBS) pattern increased the number of new myelinating oligodendrocytes in healthy adult mice. This study translates this rTMS protocol and aims to determine its safety and tolerability for people living with MS. We will also perform magnetic resonance imaging (MRI) and symptom assessments as preliminary indicators of myelin addition following rTMS. Methods Participants (N = 30, aged 18–65 years) will have a diagnosis of relapsing-remitting or secondary progressive MS. ≤2 weeks before the intervention, eligible, consenting participants will complete a physical exam, baseline brain MRI scan and participant-reported MS symptom assessments [questionnaires: Fatigue Severity Scale, Quality of Life (AQoL-8D), Hospital Anxiety and Depression Scale; and smartphone-based measures of cognition (electronic symbol digit modalities test), manual dexterity (pinching test, draw a shape test) and gait (U-Turn test)]. Participants will be pseudo-randomly allocated to rTMS (n=20) or sham (placebo; n=10), stratified by sex. rTMS or sham will be delivered 5 days per week for 4 consecutive weeks (20 sessions, 6 min per day). rTMS will be applied using a 90-mm circular coil at low-intensity (25% maximum stimulator output) in an iTBS pattern. For sham, the coil will be oriented 90° to the scalp, preventing the magnetic field from stimulating the brain. Adverse events will be recorded daily. We will evaluate participant blinding after the first, 10th and final session. After the final session, participants will repeat symptom assessments and brain MRI, for comparison with baseline. Participant-reported assessments will be repeated at 4-month post-allocation follow-up. Discussion This study will determine whether this rTMS protocol is safe and tolerable for people with MS. MRI and participant-reported symptom assessments will serve as preliminary indications of rTMS efficacy for myelin addition to inform further studies. Trial registration Australian New Zealand Clinical Trials Registry ACTRN12619001196134. Registered on 27 August 2019
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Affiliation(s)
- Kalina Makowiecki
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia.
| | - Natasha Stevens
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Carlie L Cullen
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Amin Zarghami
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Phuong Tram Nguyen
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Lewis Johnson
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Jennifer Rodger
- School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia.,Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia
| | - Mark R Hinder
- Sensorimotor Neuroscience and Ageing Research Lab, School of Psychological Sciences, University of Tasmania, Hobart, TAS, Australia
| | - Michael Barnett
- Sydney Neuroimaging Analysis Centre (SNAC), Sydney, NSW, Australia.,Brain & Mind Centre, University of Sydney, Sydney, NSW, Australia
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Bruce V Taylor
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
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Fortune AJ, Fletcher JL, Blackburn NB, Young KM. Using MS induced pluripotent stem cells to investigate MS aetiology. Mult Scler Relat Disord 2022; 63:103839. [DOI: 10.1016/j.msard.2022.103839] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 04/01/2022] [Accepted: 04/29/2022] [Indexed: 12/15/2022]
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Young KM, Rodeheffer RJ, Chen HH, Oh JK, Kane G. Left ventricular diastolic dysfunction, including an impaired myocardial relaxation pattern, predicts long-term cardiovascular and non-cardiovascular mortality in the community. Eur Heart J Cardiovasc Imaging 2022. [DOI: 10.1093/ehjci/jeab289.265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Funding Acknowledgements
Type of funding sources: None.
Background/Introduction
Prior studies have demonstrated abnormalities of diastolic function are independent predictors of heart failure and all-cause mortality. The optimal way to classify diastolic function has continued to evolve over time, particularly in those with preserved left ventricular ejection fraction. A notable change in the 2016 American Society of Echocardiography (ASE)/European Association of Cardiovascular Imaging (EACVI) guidelines is that individuals with impaired myocardial relaxation and normal filling pressure can be classified as normal diastolic function.
Purpose
To determine whether the association of diastolic dysfunction with increased risk of all-cause mortality is driven by cardiovascular or non-cardiovascular death. Second, to evaluate if the presence of an impaired myocardial relaxation inflow pattern without other diastolic abnormalities conveys a marker of increased risk.
Methods
This study utilized the Olmsted County Heart Function Study (OCHFS), a well characterized prospective adult community cohort with comprehensive echocardiography between 2001 and 2004 and long-term follow-up. Only individuals with measurable diastolic function were included (n = 1,104). Those with reduced left ventricular ejection fraction, more than moderate valve disease, or a clinical diagnosis of heart failure (n = 52); or indeterminate diastolic function (n = 47) were excluded. Diastolic function was assessed by the current Mayo Clinic diagnostic algorithm (Figure).
Results
A total of 695 individuals were classified as normal, 265 with impaired myocardial relaxation or grade 1 diastolic dysfunction, and 45 with grade 2-3 diastolic dysfunction. Those with diastolic dysfunction were older and had more comorbidities including diabetes, hypertension and coronary disease (Table). There were 264 deaths in the median follow up period of 15.2 years (IQR 14.4 – 18.0), including 173 non-cardiovascular and 81 cardiovascular deaths. Both cardiovascular and non-cardiovascular mortality were associated with the presence and grade of diastolic dysfunction (Table 1). Individuals classified as normal by 2016 ASE/EACVI criteria, but grade 1 by the Mayo algorithm had an increased risk of all-cause mortality after univariate analysis (HR 4.35, 95% CI (3.35, 5.65), p < 0.0001) compared to normal subjects and remained associated after adjustment for age (HR 1.55, 95% CI (1.15, 2.09), p < 0.0001. Subjects with a grade 1 pattern had a higher rate of cardiovascular mortality (ꭕ2 70.1, p < 0.0001).
Conclusions
Individuals with diastolic dysfunction, including those with an impaired relaxation mitral inflow, were at increased risk of mortality, particularly cardiovascular mortality. This study highlights the importance of separating grade 1 diastolic dysfunction from normal in the assessment of diastolic function as it represents a clinically significant risk marker of myocardial disease. Abstract Figure. Abstract Figure.
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Affiliation(s)
- KM Young
- Mayo Clinic, Rochester, United States of America
| | | | - HH Chen
- Mayo Clinic, Rochester, United States of America
| | - JK Oh
- Mayo Clinic, Rochester, United States of America
| | - G Kane
- Mayo Clinic, Rochester, United States of America
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Mehta A, Lu P, Taylor BV, Charlesworth J, Cook AL, Burdon KP, Hewitt AW, Young KM. Generation of MNZTASi001-A, a human pluripotent stem cell line from a person with primary progressive multiple sclerosis. Stem Cell Res 2021; 57:102568. [PMID: 34678664 DOI: 10.1016/j.scr.2021.102568] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [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: 09/07/2021] [Revised: 10/05/2021] [Accepted: 10/10/2021] [Indexed: 11/22/2022] Open
Abstract
Multiple sclerosis (MS) is a chronic autoimmune and neurodegenerative disease that results in immune cell infiltration of the central nervous system (CNS) and demyelination in young adults. Substantial progress has been made in developing disease modifying therapies for people with relapsing-remitting MS, but options remain limited for people with primary progressive MS (PPMS). PPMS accounts for ∼15% of MS diagnoses. Herein, we generated a human induced pluripotent stem cell line (hiPSC) from a person with clinically definite PPMS. This disease-specific hiPSC line will be useful for studying PPMS in vitro, allowing the generation of immune and CNS cell types.
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Affiliation(s)
- Ashish Mehta
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Peter Lu
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Bruce V Taylor
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Jac Charlesworth
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Anthony L Cook
- Wicking Dementia Research and Education Centre, University of Tasmania, Hobart, Australia
| | - Kathryn P Burdon
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Alex W Hewitt
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia.
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Ferreira S, Pitman KA, Summers BS, Wang S, Young KM, Cullen CL. Oligodendrogenesis increases in hippocampal grey and white matter prior to locomotor or memory impairment in an adult mouse model of tauopathy. Eur J Neurosci 2021; 54:5762-5784. [PMID: 32181929 PMCID: PMC8451881 DOI: 10.1111/ejn.14726] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 03/11/2020] [Accepted: 03/11/2020] [Indexed: 12/12/2022]
Abstract
Myelin and axon losses are associated with cognitive decline in healthy ageing but are worse in people diagnosed with tauopathy. To determine whether tauopathy is also associated with enhanced myelin plasticity, we evaluated the behaviour of OPCs in mice that expressed a human pathological variant of microtubule-associated protein tau (MAPTP301S ). By 6 months of age (P180), MAPTP301S mice overexpressed hyperphosphorylated tau and had developed reactive gliosis in the hippocampus but had not developed overt locomotor or memory impairment. By performing cre-lox lineage tracing of adult OPCs, we determined that the number of newborn oligodendrocytes added to the hippocampus, entorhinal cortex and fimbria was equivalent in control and MAPTP301S mice prior to P150. However, between P150 and P180, significantly more new oligodendrocytes were added to these regions in the MAPTP301S mouse brain. This large increase in new oligodendrocyte number was not the result of increased OPC proliferation, nor did it alter oligodendrocyte density in the hippocampus, entorhinal cortex or fimbria, which was equivalent in P180 wild-type and MAPTP301S mice. Furthermore, the proportion of hippocampal and fimbria axons with myelin was unaffected by tauopathy. However, the proportion of myelinated axons that were ensheathed by immature myelin internodes was significantly increased in the hippocampus and fimbria of P180 MAPTP301S mice, when compared with their wild-type littermates. These data suggest that MAPTP301S transgenic mice experience significant oligodendrocyte turnover, with newborn oligodendrocytes compensating for myelin loss early in the development of tauopathy.
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Affiliation(s)
- Solène Ferreira
- Menzies Institute for Medical ResearchUniversity of TasmaniaHobartTasmaniaAustralia
| | - Kimberley A. Pitman
- Menzies Institute for Medical ResearchUniversity of TasmaniaHobartTasmaniaAustralia
| | - Benjamin S. Summers
- Menzies Institute for Medical ResearchUniversity of TasmaniaHobartTasmaniaAustralia
| | - Shiwei Wang
- Menzies Institute for Medical ResearchUniversity of TasmaniaHobartTasmaniaAustralia
| | - Kaylene M. Young
- Menzies Institute for Medical ResearchUniversity of TasmaniaHobartTasmaniaAustralia
| | - Carlie L. Cullen
- Menzies Institute for Medical ResearchUniversity of TasmaniaHobartTasmaniaAustralia
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Fletcher JL, Makowiecki K, Cullen CL, Young KM. Oligodendrogenesis and myelination regulate cortical development, plasticity and circuit function. Semin Cell Dev Biol 2021; 118:14-23. [PMID: 33863642 DOI: 10.1016/j.semcdb.2021.03.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [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: 01/20/2021] [Revised: 03/23/2021] [Accepted: 03/25/2021] [Indexed: 12/17/2022]
Abstract
During cortical development and throughout adulthood, oligodendrocytes add myelin internodes to glutamatergic projection neurons and GABAergic inhibitory neurons. In addition to directing node of Ranvier formation, to enable saltatory conduction and influence action potential transit time, oligodendrocytes support axon health by communicating with axons via the periaxonal space and providing metabolic support that is particularly critical for healthy ageing. In this review we outline the timing of oligodendrogenesis in the developing mouse and human cortex and describe the important role that oligodendrocytes play in sustaining and modulating neuronal function. We also provide insight into the known and speculative impact that myelination has on cortical axons and their associated circuits during the developmental critical periods and throughout life, particularly highlighting their life-long role in learning and remembering.
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Affiliation(s)
- Jessica L Fletcher
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Kalina Makowiecki
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Carlie L Cullen
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia.
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Cullen CL, Pepper RE, Clutterbuck MT, Pitman KA, Oorschot V, Auderset L, Tang AD, Ramm G, Emery B, Rodger J, Jolivet RB, Young KM. Periaxonal and nodal plasticities modulate action potential conduction in the adult mouse brain. Cell Rep 2021; 34:108641. [PMID: 33472075 DOI: 10.1016/j.celrep.2020.108641] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [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: 05/22/2020] [Revised: 11/18/2020] [Accepted: 12/21/2020] [Indexed: 12/25/2022] Open
Abstract
Central nervous system myelination increases action potential conduction velocity. However, it is unclear how myelination is coordinated to ensure the temporally precise arrival of action potentials and facilitate information processing within cortical and associative circuits. Here, we show that myelin sheaths, supported by mature oligodendrocytes, remain plastic in the adult mouse brain and undergo subtle structural modifications to influence action potential conduction velocity. Repetitive transcranial magnetic stimulation and spatial learning, two stimuli that modify neuronal activity, alter the length of the nodes of Ranvier and the size of the periaxonal space within active brain regions. This change in the axon-glial configuration is independent of oligodendrogenesis and robustly alters action potential conduction velocity. Because aptitude in the spatial learning task was found to correlate with action potential conduction velocity in the fimbria-fornix pathway, modifying the axon-glial configuration may be a mechanism that facilitates learning in the adult mouse brain.
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Affiliation(s)
- Carlie L Cullen
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia
| | - Renee E Pepper
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia
| | | | - Kimberley A Pitman
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia
| | - Viola Oorschot
- Ramaciotti Centre for Cryo-Electron Microscopy, Monash University, Melbourne, VIC 3800, Australia
| | - Loic Auderset
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia
| | - Alexander D Tang
- Experimental and Regenerative Neuroscience, School of Biological Sciences, University of Western Australia, Perth, WA 6009, Australia
| | - Georg Ramm
- Ramaciotti Centre for Cryo-Electron Microscopy, Monash University, Melbourne, VIC 3800, Australia
| | - Ben Emery
- Jungers Center for Neurosciences Research, Department of Neurology, Oregon Health and Science University, Portland, OR 97239-3098, USA
| | - Jennifer Rodger
- Experimental and Regenerative Neuroscience, School of Biological Sciences, University of Western Australia, Perth, WA 6009, Australia; Perron Institute for Neurological and Translational Research, Perth, WA 6009, Australia
| | - Renaud B Jolivet
- Département de Physique Nucléaire et Corpusculaire, University of Geneva, 1211 Geneva 4, Switzerland
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia.
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11
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Cullen CL, O'Rourke M, Beasley SJ, Auderset L, Zhen Y, Pepper RE, Gasperini R, Young KM. Kif3a deletion prevents primary cilia assembly on oligodendrocyte progenitor cells, reduces oligodendrogenesis and impairs fine motor function. Glia 2020; 69:1184-1203. [PMID: 33368703 PMCID: PMC7986221 DOI: 10.1002/glia.23957] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [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] [Received: 09/16/2020] [Revised: 11/06/2020] [Accepted: 12/10/2020] [Indexed: 12/17/2022]
Abstract
Primary cilia are small microtubule‐based organelles capable of transducing signals from growth factor receptors embedded in the cilia membrane. Developmentally, oligodendrocyte progenitor cells (OPCs) express genes associated with primary cilia assembly, disassembly, and signaling, however, the importance of primary cilia for adult myelination has not been explored. We show that OPCs are ciliated in vitro and in vivo, and that they disassemble their primary cilia as they progress through the cell cycle. OPC primary cilia are also disassembled as OPCs differentiate into oligodendrocytes. When kinesin family member 3a (Kif3a), a gene critical for primary cilium assembly, was conditionally deleted from adult OPCs in vivo (Pdgfrα‐CreER™:: Kif3afl/fl transgenic mice), OPCs failed to assemble primary cilia. Kif3a‐deletion was also associated with reduced OPC proliferation and oligodendrogenesis in the corpus callosum and motor cortex and a progressive impairment of fine motor coordination.
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Affiliation(s)
- Carlie L Cullen
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Megan O'Rourke
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Shannon J Beasley
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Loic Auderset
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Yilan Zhen
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Renee E Pepper
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Robert Gasperini
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia.,School of Medicine, University of Tasmania, Hobart, Australia
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
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12
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Auderset L, Pitman KA, Cullen CL, Pepper RE, Taylor BV, Foa L, Young KM. Low-Density Lipoprotein Receptor-Related Protein 1 (LRP1) Is a Negative Regulator of Oligodendrocyte Progenitor Cell Differentiation in the Adult Mouse Brain. Front Cell Dev Biol 2020; 8:564351. [PMID: 33282858 PMCID: PMC7691426 DOI: 10.3389/fcell.2020.564351] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [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] [Received: 05/21/2020] [Accepted: 09/14/2020] [Indexed: 12/17/2022] Open
Abstract
Low-density lipoprotein receptor-related protein 1 (LRP1) is a large, endocytic cell surface receptor that is highly expressed by oligodendrocyte progenitor cells (OPCs) and LRP1 expression is rapidly downregulated as OPCs differentiate into oligodendrocytes (OLs). We report that the conditional deletion of Lrp1 from adult mouse OPCs (Pdgfrα-CreER :: Lrp1fl/fl) increases the number of newborn, mature myelinating OLs added to the corpus callosum and motor cortex. As these additional OLs extend a normal number of internodes that are of a normal length, Lrp1-deletion increases adult myelination. OPC proliferation is also elevated following Lrp1 deletion in vivo, however, this may be a secondary, homeostatic response to increased OPC differentiation, as our in vitro experiments show that LRP1 is a direct negative regulator of OPC differentiation, not proliferation. Deleting Lrp1 from adult OPCs also increases the number of newborn mature OLs added to the corpus callosum in response to cuprizone-induced demyelination. These data suggest that the selective blockade of LRP1 function on adult OPCs may enhance myelin repair in demyelinating diseases such as multiple sclerosis.
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Affiliation(s)
- Loic Auderset
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Kimberley A Pitman
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Carlie L Cullen
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Renee E Pepper
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Bruce V Taylor
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Lisa Foa
- School of Medicine, University of Tasmania, Hobart, TAS, Australia
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
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13
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Li F, Wing K, Wang JH, Luu CD, Bender JA, Chen J, Wang Q, Lu Q, Nguyen Tran MT, Young KM, Wong RCB, Pébay A, Cook AL, Hung SSC, Liu GS, Hewitt AW. Comparison of CRISPR/Cas Endonucleases for in vivo Retinal Gene Editing. Front Cell Neurosci 2020; 14:570917. [PMID: 33132845 PMCID: PMC7511709 DOI: 10.3389/fncel.2020.570917] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [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] [Received: 06/09/2020] [Accepted: 08/18/2020] [Indexed: 12/15/2022] Open
Abstract
CRISPR/Cas has opened the prospect of direct gene correction therapy for some inherited retinal diseases. Previous work has demonstrated the utility of adeno-associated virus (AAV) mediated delivery to retinal cells in vivo; however, with the expanding repertoire of CRISPR/Cas endonucleases, it is not clear which of these are most efficacious for retinal editing in vivo. We sought to compare CRISPR/Cas endonuclease activity using both single and dual AAV delivery strategies for gene editing in retinal cells. Plasmids of a dual vector system with SpCas9, SaCas9, Cas12a, CjCas9 and a sgRNA targeting YFP, as well as a single vector system with SaCas9/YFP sgRNA were generated and validated in YFP-expressing HEK293A cell by flow cytometry and the T7E1 assay. Paired CRISPR/Cas endonuclease and its best performing sgRNA was then packaged into an AAV2 capsid derivative, AAV7m8, and injected intravitreally into CMV-Cre:Rosa26-YFP mice. SpCas9 and Cas12a achieved better knockout efficiency than SaCas9 and CjCas9. Moreover, no significant difference in YFP gene editing was found between single and dual CRISPR/SaCas9 vector systems. With a marked reduction of YFP-positive retinal cells, AAV7m8 delivered SpCas9 was found to have the highest knockout efficacy among all investigated endonucleases. We demonstrate that the AAV7m8-mediated delivery of CRISPR/SpCas9 construct achieves the most efficient gene modification in neurosensory retinal cells in vivo.
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Affiliation(s)
- Fan Li
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia.,State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Centre, Sun Yat-sen University, Guangzhou, China
| | - Kristof Wing
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Jiang-Hui Wang
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
| | - Chi D Luu
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia.,Ophthalmology, Department of Surgery, The University of Melbourne, Parkville, VIC, Australia
| | - James A Bender
- Wicking Dementia Research and Education Centre, University of Tasmania, Hobart, TAS, Australia
| | - Jinying Chen
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia.,Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Qi Wang
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Qinyi Lu
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | | | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Raymond C B Wong
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia.,Ophthalmology, Department of Surgery, The University of Melbourne, Parkville, VIC, Australia
| | - Alice Pébay
- Department of Surgery, Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, Australia.,Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, VIC, Australia
| | - Anthony L Cook
- Wicking Dementia Research and Education Centre, University of Tasmania, Hobart, TAS, Australia
| | - Sandy S C Hung
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia.,Ophthalmology, Department of Surgery, The University of Melbourne, Parkville, VIC, Australia
| | - Guei-Sheung Liu
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia.,Ophthalmology, Department of Surgery, The University of Melbourne, Parkville, VIC, Australia
| | - Alex W Hewitt
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia.,Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
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14
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Ferreira S, Pitman KA, Wang S, Summers BS, Bye N, Young KM, Cullen CL. Amyloidosis is associated with thicker myelin and increased oligodendrogenesis in the adult mouse brain. J Neurosci Res 2020; 98:1905-1932. [PMID: 32557778 PMCID: PMC7540704 DOI: 10.1002/jnr.24672] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [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] [Received: 01/23/2020] [Revised: 05/03/2020] [Accepted: 05/25/2020] [Indexed: 12/15/2022]
Abstract
In Alzheimer's disease, amyloid plaque formation is associated with the focal death of oligodendrocytes and soluble amyloid β impairs the survival of oligodendrocytes in vitro. However, the response of oligodendrocyte progenitor cells (OPCs) to early amyloid pathology remains unclear. To explore this, we performed a histological, electrophysiological, and behavioral characterization of transgenic mice expressing a pathological form of human amyloid precursor protein (APP), containing three single point mutations associated with the development of familial Alzheimer's disease (PDGFB‐APPSw.Ind, also known as J20 mice). PDGFB‐APPSw.Ind transgenic mice had impaired survival from weaning, were hyperactive by 2 months of age, and developed amyloid plaques by 6 months of age, however, their spatial memory remained intact over this time course. Hippocampal OPC density was normal in P60‐P180 PDGFB‐APPSw.Ind transgenic mice and, by performing whole‐cell patch‐clamp electrophysiology, we found that their membrane properties, including their response to kainate (100 µM), were largely normal. However, by P100, the response of hippocampal OPCs to GABA was elevated in PDGFB‐APPSw.Ind transgenic mice. We also found that the nodes of Ranvier were shorter, the paranodes longer, and the myelin thicker for hippocampal axons in young adult PDGFB‐APPSw.Ind transgenic mice compared with wildtype littermates. Additionally, oligodendrogenesis was normal in young adulthood, but increased in the hippocampus, entorhinal cortex, and fimbria of PDGFB‐APPSw.Ind transgenic mice as pathology developed. As the new oligodendrocytes were not associated with a change in total oligodendrocyte number, these cells are likely required for cell replacement.
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Affiliation(s)
- Solène Ferreira
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Kimberley A Pitman
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Shiwei Wang
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Benjamin S Summers
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Nicole Bye
- School of Medicine, University of Tasmania, Hobart, Tasmania, Australia
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Carlie L Cullen
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
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15
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Pitman KA, Ricci R, Gasperini R, Beasley S, Pavez M, Charlesworth J, Foa L, Young KM. The voltage-gated calcium channel CaV1.2 promotes adult oligodendrocyte progenitor cell survival in the mouse corpus callosum but not motor cortex. Glia 2019; 68:376-392. [PMID: 31605513 PMCID: PMC6916379 DOI: 10.1002/glia.23723] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [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] [Received: 09/24/2018] [Revised: 09/02/2019] [Accepted: 09/10/2019] [Indexed: 12/21/2022]
Abstract
Throughout life, oligodendrocyte progenitor cells (OPCs) proliferate and differentiate into myelinating oligodendrocytes. OPCs express cell surface receptors and channels that allow them to detect and respond to neuronal activity, including voltage‐gated calcium channel (VGCC)s. The major L‐type VGCC expressed by developmental OPCs, CaV1.2, regulates their differentiation. However, it is unclear whether CaV1.2 similarly influences OPC behavior in the healthy adult central nervous system (CNS). To examine the role of CaV1.2 in adulthood, we conditionally deleted this channel from OPCs by administering tamoxifen to P60 Cacna1cfl/fl (control) and Pdgfrα‐CreER:: Cacna1cfl/fl (CaV1.2‐deleted) mice. Whole cell patch clamp analysis revealed that CaV1.2 deletion reduced L‐type voltage‐gated calcium entry into adult OPCs by ~60%, confirming that it remains the major L‐type VGCC expressed by OPCs in adulthood. The conditional deletion of CaV1.2 from adult OPCs significantly increased their proliferation but did not affect the number of new oligodendrocytes produced or influence the length or number of internodes they elaborated. Unexpectedly, CaV1.2 deletion resulted in the dramatic loss of OPCs from the corpus callosum, such that 7 days after tamoxifen administration CaV1.2‐deleted mice had an OPC density ~42% that of control mice. OPC density recovered within 2 weeks of CaV1.2 deletion, as the lost OPCs were replaced by surviving CaV1.2‐deleted OPCs. As OPC density was not affected in the motor cortex or spinal cord, we conclude that calcium entry through CaV1.2 is a critical survival signal for a subpopulation of callosal OPCs but not for all OPCs in the mature CNS.
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Affiliation(s)
- Kimberley A Pitman
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Raphael Ricci
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Robert Gasperini
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia.,School of Medicine, University of Tasmania, Hobart, Australia
| | - Shannon Beasley
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Macarena Pavez
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Jac Charlesworth
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Lisa Foa
- School of Medicine, University of Tasmania, Hobart, Australia
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
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16
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Cullen CL, Senesi M, Tang AD, Clutterbuck MT, Auderset L, O'Rourke ME, Rodger J, Young KM. Low-intensity transcranial magnetic stimulation promotes the survival and maturation of newborn oligodendrocytes in the adult mouse brain. Glia 2019; 67:1462-1477. [PMID: 30989733 PMCID: PMC6790715 DOI: 10.1002/glia.23620] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [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] [Received: 08/25/2018] [Revised: 03/05/2019] [Accepted: 03/25/2019] [Indexed: 11/23/2022]
Abstract
Neuronal activity is a potent extrinsic regulator of oligodendrocyte generation and central nervous system myelination. Clinically, repetitive transcranial magnetic stimulation (rTMS) is delivered to noninvasively modulate neuronal activity; however, the ability of rTMS to facilitate adaptive myelination has not been explored. By performing cre‐lox lineage tracing, to follow the fate of oligodendrocyte progenitor cells in the adult mouse brain, we determined that low intensity rTMS (LI‐rTMS), administered as an intermittent theta burst stimulation, but not as a continuous theta burst or 10 Hz stimulation, increased the number of newborn oligodendrocytes in the adult mouse cortex. LI‐rTMS did not alter oligodendrogenesis per se, but instead increased cell survival and enhanced myelination. These data suggest that LI‐rTMS can be used to noninvasively promote myelin addition to the brain, which has potential implications for the treatment of demyelinating diseases such as multiple sclerosis.
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Affiliation(s)
- Carlie L Cullen
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Matteo Senesi
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Alexander D Tang
- Experimental and Regenerative Neurosciences, School of Biological Sciences, University of Western Australia, Perth, Western Australia, Australia
| | | | - Loic Auderset
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Megan E O'Rourke
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Jennifer Rodger
- Experimental and Regenerative Neurosciences, School of Biological Sciences, University of Western Australia, Perth, Western Australia, Australia.,Brain Plasticity Lab, Perron Institute for Neurological and Translational Science, Perth, Western Australia, Australia
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
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17
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Stierli S, Napoli I, White IJ, Cattin AL, Monteza Cabrejos A, Garcia Calavia N, Malong L, Ribeiro S, Nihouarn J, Williams R, Young KM, Richardson WD, Lloyd AC. The regulation of the homeostasis and regeneration of peripheral nerve is distinct from the CNS and independent of a stem cell population. Development 2018; 145:dev170316. [PMID: 30413560 PMCID: PMC6307893 DOI: 10.1242/dev.170316] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 10/30/2018] [Indexed: 12/22/2022]
Abstract
Peripheral nerves are highly regenerative, in contrast to the poor regenerative capabilities of the central nervous system (CNS). Here, we show that adult peripheral nerve is a more quiescent tissue than the CNS, yet all cell types within a peripheral nerve proliferate efficiently following injury. Moreover, whereas oligodendrocytes are produced throughout life from a precursor pool, we find that the corresponding cell of the peripheral nervous system, the myelinating Schwann cell (mSC), does not turn over in the adult. However, following injury, all mSCs can dedifferentiate to the proliferating progenitor-like Schwann cells (SCs) that orchestrate the regenerative response. Lineage analysis shows that these newly migratory, progenitor-like cells redifferentiate to form new tissue at the injury site and maintain their lineage, but can switch to become a non-myelinating SC. In contrast, increased plasticity is observed during tumourigenesis. These findings show that peripheral nerves have a distinct mechanism for maintaining homeostasis and can regenerate without the need for an additional stem cell population.This article has an associated 'The people behind the papers' interview.
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Affiliation(s)
- Salome Stierli
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Ilaria Napoli
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Ian J White
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Anne-Laure Cattin
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Anthony Monteza Cabrejos
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Noelia Garcia Calavia
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Liza Malong
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Sara Ribeiro
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Julie Nihouarn
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Richard Williams
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia
| | - William D Richardson
- Wolfson Institute for Biomedical Research, University College London (UCL), Gower Street, London WC1E 6BT, UK
| | - Alison C Lloyd
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
- UCL Cancer Institute, University College London, Gower Street, London WC1E 6BT, UK
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18
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Pepper RE, Pitman KA, Cullen CL, Young KM. How Do Cells of the Oligodendrocyte Lineage Affect Neuronal Circuits to Influence Motor Function, Memory and Mood? Front Cell Neurosci 2018; 12:399. [PMID: 30524235 PMCID: PMC6262292 DOI: 10.3389/fncel.2018.00399] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [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] [Received: 07/30/2018] [Accepted: 10/17/2018] [Indexed: 12/11/2022] Open
Abstract
Oligodendrocyte progenitor cells (OPCs) are immature cells in the central nervous system (CNS) that can rapidly respond to changes within their environment by modulating their proliferation, motility and differentiation. OPCs differentiate into myelinating oligodendrocytes throughout life, and both cell types have been implicated in maintaining and modulating neuronal function to affect motor performance, cognition and emotional state. However, questions remain about the mechanisms employed by OPCs and oligodendrocytes to regulate circuit function, including whether OPCs can only influence circuits through their generation of new oligodendrocytes, or can play other regulatory roles within the CNS. In this review, we detail the molecular and cellular mechanisms that allow OPCs, newborn oligodendrocytes and pre-existing oligodendrocytes to regulate circuit function and ultimately influence behavioral outcomes.
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Affiliation(s)
- Renee E Pepper
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Kimberley A Pitman
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Carlie L Cullen
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
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19
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Handley EE, Pitman KA, Dawkins E, Young KM, Clark RM, Jiang TC, Turner BJ, Dickson TC, Blizzard CA. Synapse Dysfunction of Layer V Pyramidal Neurons Precedes Neurodegeneration in a Mouse Model of TDP-43 Proteinopathies. Cereb Cortex 2018; 27:3630-3647. [PMID: 27496536 DOI: 10.1093/cercor/bhw185] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
TDP-43 is a major protein component of pathological neuronal inclusions that are present in frontotemporal dementia and amyotrophic lateral sclerosis. We report that TDP-43 plays an important role in dendritic spine formation in the cortex. The density of spines on YFP+ pyramidal neurons in both the motor and somatosensory cortex of Thy1-YFP mice, increased significantly from postnatal day 30 (P30), to peak at P60, before being pruned by P90. By comparison, dendritic spine density was significantly reduced in the motor cortex of Thy1-YFP::TDP-43A315T transgenic mice prior to symptom onset (P60), and in the motor and somatosensory cortex at symptom onset (P90). Morphological spine-type analysis revealed that there was a significant impairment in the development of basal mushroom spines in the motor cortex of Thy1-YFP::TDP-43A315T mice compared to Thy1-YFP control. Furthermore, reductions in spine density corresponded to mislocalisation of TDP-43 immunoreactivity and lowered efficacy of synaptic transmission as determined by electrophysiology at P60. We conclude that mutated TDP-43 has a significant pathological effect at the dendritic spine that is associated with attenuated neural transmission.
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Affiliation(s)
- Emily E Handley
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia
| | - Kimberley A Pitman
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia
| | - Edgar Dawkins
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia
| | - Rosemary M Clark
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia
| | - Tongcui C Jiang
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia
| | - Bradley J Turner
- Florey Institute for Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC 3052, Australia
| | - Tracey C Dickson
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia
| | - Catherine A Blizzard
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia
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20
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Cullen CL, Young KM. Can Thyroid Hormone Analogues Be Used to Overcome Hypomyelination and Demyelination of the Central Nervous System? EBioMedicine 2017; 26:15-16. [PMID: 29128443 PMCID: PMC5832563 DOI: 10.1016/j.ebiom.2017.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 11/06/2017] [Indexed: 11/27/2022] Open
Affiliation(s)
- Carlie L Cullen
- Menzies Institute for Medical Research, University of Tasmania, 17 Liverpool St, Hobart 7000, Australia
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, 17 Liverpool St, Hobart 7000, Australia.
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21
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Brizuela M, Blizzard CA, Chuckowree JA, Pitman KA, Young KM, Dickson T. Mild Traumatic Brain Injury Leads to Decreased Inhibition and a Differential Response of Calretinin Positive Interneurons in the Injured Cortex. J Neurotrauma 2017; 34:2504-2517. [DOI: 10.1089/neu.2017.4977] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Affiliation(s)
- Mariana Brizuela
- Menzies Institute for Medical Research, University of Tasmania, Tasmania, Australia
| | | | - Jyoti A. Chuckowree
- Menzies Institute for Medical Research, University of Tasmania, Tasmania, Australia
| | - Kimberley A. Pitman
- Menzies Institute for Medical Research, University of Tasmania, Tasmania, Australia
| | - Kaylene M. Young
- Menzies Institute for Medical Research, University of Tasmania, Tasmania, Australia
| | - Tracey Dickson
- Menzies Institute for Medical Research, University of Tasmania, Tasmania, Australia
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22
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Gasperini RJ, Pavez M, Thompson AC, Mitchell CB, Hardy H, Young KM, Chilton JK, Foa L. How does calcium interact with the cytoskeleton to regulate growth cone motility during axon pathfinding? Mol Cell Neurosci 2017; 84:29-35. [PMID: 28765051 DOI: 10.1016/j.mcn.2017.07.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [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: 11/30/2016] [Revised: 07/27/2017] [Accepted: 07/28/2017] [Indexed: 02/04/2023] Open
Abstract
The precision with which neurons form connections is crucial for the normal development and function of the nervous system. The development of neuronal circuitry in the nervous system is accomplished by axon pathfinding: a process where growth cones guide axons through the embryonic environment to connect with their appropriate synaptic partners to form functional circuits. Despite intense efforts over many years to understand how this process is regulated, the complete repertoire of molecular mechanisms that govern the growth cone cytoskeleton and hence motility, remain unresolved. A central tenet in the axon guidance field is that calcium signals regulate growth cone behaviours such as extension, turning and pausing by regulating rearrangements of the growth cone cytoskeleton. Here, we provide evidence that not only the amplitude of a calcium signal is critical for growth cone motility but also the source of calcium mobilisation. We provide an example of this idea by demonstrating that manipulation of calcium signalling via L-type voltage gated calcium channels can perturb sensory neuron motility towards a source of netrin-1. Understanding how calcium signals can be transduced to initiate cytoskeletal changes represents a significant gap in our current knowledge of the mechanisms that govern axon guidance, and consequently the formation of functional neural circuits in the developing nervous system.
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Affiliation(s)
- Robert J Gasperini
- School of Medicine, University of Tasmania, Hobart, Tasmania 7001, Australia.
| | - Macarena Pavez
- School of Medicine, University of Tasmania, Hobart, Tasmania 7001, Australia.
| | - Adrian C Thompson
- School of Medicine, University of Tasmania, Hobart, Tasmania 7001, Australia.
| | - Camilla B Mitchell
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania 7001, Australia.
| | - Holly Hardy
- University of Exeter Medical School, Wellcome Wolfson Centre for Medical Research, Exeter EX2 5DW, United Kingdom.
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania 7001, Australia.
| | - John K Chilton
- University of Exeter Medical School, Wellcome Wolfson Centre for Medical Research, Exeter EX2 5DW, United Kingdom.
| | - Lisa Foa
- School of Medicine, University of Tasmania, Hobart, Tasmania 7001, Australia.
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Clark RM, Blizzard CA, Young KM, King AE, Dickson TC. Calretinin and Neuropeptide Y interneurons are differentially altered in the motor cortex of the SOD1 G93A mouse model of ALS. Sci Rep 2017; 7:44461. [PMID: 28294153 PMCID: PMC5353592 DOI: 10.1038/srep44461] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 02/08/2017] [Indexed: 12/13/2022] Open
Abstract
Increasing evidence indicates an excitatory/inhibitory imbalance may have a critical role in the pathogenesis of amyotrophic lateral sclerosis (ALS). Impaired inhibitory circuitry is consistently reported in the motor cortex of both familial and sporadic patients, closely associated with cortical hyperexcitability and ALS onset. Inhibitory network dysfunction is presumably mediated by intra-cortical inhibitory interneurons, however, the exact cell types responsible are yet to be identified. In this study we demonstrate dynamic changes in the number of calretinin- (CR) and neuropeptide Y-expressing (NPY) interneurons in the motor cortex of the familial hSOD1G93A ALS mouse model, suggesting their potential involvement in motor neuron circuitry defects. We show that the density of NPY-populations is significantly decreased by ~17% at symptom onset (8 weeks), and by end-stage disease (20 weeks) is significantly increased by ~30%. Conversely, the density of CR-populations is progressively reduced during later symptomatic stages (~31%) to end-stage (~36%), while CR-expressing interneurons also show alteration of neurite branching patterns at symptom onset. We conclude that a differential capacity for interneurons exists in the ALS motor cortex, which may not be a static phenomenon, but involves early dynamic changes throughout disease, implicating specific inhibitory circuitry.
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Affiliation(s)
- Rosemary M Clark
- Menzies Institute for Medical Research, University of Tasmania, Hobart, 7000, Australia
| | - Catherine A Blizzard
- Menzies Institute for Medical Research, University of Tasmania, Hobart, 7000, Australia
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, 7000, Australia
| | - Anna E King
- Wicking Dementia Research &Education Centre2, University of Tasmania, Hobart, 7000, Australia
| | - Tracey C Dickson
- Menzies Institute for Medical Research, University of Tasmania, Hobart, 7000, Australia
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24
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Wang S, Bolós M, Clark R, Cullen CL, Southam KA, Foa L, Dickson TC, Young KM. Amyloid β precursor protein regulates neuron survival and maturation in the adult mouse brain. Mol Cell Neurosci 2016; 77:21-33. [DOI: 10.1016/j.mcn.2016.09.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 08/12/2016] [Accepted: 09/19/2016] [Indexed: 01/08/2023] Open
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25
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Lahti M, Pussi K, Smerdon JA, Young KM, Sharma HR, McGrath R. Coverage-dependent structural phase transformations in the adsorption of pentacene on an aperiodically modulated Cu film. J Chem Phys 2016; 145:154707. [PMID: 27782456 DOI: 10.1063/1.4964920] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Surface ordering of pentacene molecules adsorbed on an aperiodic Cu surface has been studied with density functional theory (DFT) and scanning tunnelling microscopy as a function of coverage. Below 0.73 ML (5.3 × 1013 molecules cm-2), the adsorbate structure is row-like with the molecular axes aligned with the rows in the Cu structure. Between this coverage and 1 ML (7.3 × 1013 molecules cm-2), a structural phase with a checkerboard structure is seen. At this coverage region, the molecules are very close to each other which leads to unusual bending. At higher coverages, a further phase transition to a high-density row structure is seen for most of the film. DFT with van der Waals functionals is employed to study how the molecule-molecule and molecule-surface interactions evolve as a function of coverage.
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Affiliation(s)
- M Lahti
- School of Engineering Science, Lappeenranta University of Technology, P.O. Box 20, FIN-53851 Lappeenranta, Finland
| | - K Pussi
- School of Engineering Science, Lappeenranta University of Technology, P.O. Box 20, FIN-53851 Lappeenranta, Finland
| | - J A Smerdon
- Jeremiah Horrocks Institute for Mathematics, Physics and Astronomy, University of Central Lancashire, Preston PR1 2HE, United Kingdom
| | - K M Young
- Surface Science Research Centre, University of Liverpool, Oxford St., Liverpool L69 3BX, United Kingdom
| | - H R Sharma
- Surface Science Research Centre, University of Liverpool, Oxford St., Liverpool L69 3BX, United Kingdom
| | - R McGrath
- Surface Science Research Centre, University of Liverpool, Oxford St., Liverpool L69 3BX, United Kingdom
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26
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O’Rourke M, Cullen CL, Auderset L, Pitman KA, Achatz D, Gasperini R, Young KM. Evaluating Tissue-Specific Recombination in a Pdgfrα-CreERT2 Transgenic Mouse Line. PLoS One 2016; 11:e0162858. [PMID: 27626928 PMCID: PMC5023134 DOI: 10.1371/journal.pone.0162858] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 08/30/2016] [Indexed: 11/18/2022] Open
Abstract
In the central nervous system (CNS) platelet derived growth factor receptor alpha (PDGFRα) is expressed exclusively by oligodendrocyte progenitor cells (OPCs), making the Pdgfrα promoter an ideal tool for directing transgene expression in this cell type. Two Pdgfrα-CreERT2 mouse lines have been generated for this purpose which, when crossed with cre-sensitive reporter mice, allow the temporally restricted labelling of OPCs for lineage-tracing studies. These mice have also been used to achieve the deletion of CNS-specific genes from OPCs. However the ability of Pdgfrα-CreERT2 mice to induce cre-mediated recombination in PDGFRα+ cell populations located outside of the CNS has not been examined. Herein we quantify the proportion of PDGFRα+ cells that become YFP-labelled following Tamoxifen administration to adult Pdgfrα-CreERT2::Rosa26-YFP transgenic mice. We report that the vast majority (>90%) of PDGFRα+ OPCs in the CNS, and a significant proportion of PDGFRα+ stromal cells within the bone marrow (~38%) undergo recombination and become YFP-labelled. However, only a small proportion of the PDGFRα+ cell populations found in the sciatic nerve, adrenal gland, pituitary gland, heart, gastrocnemius muscle, kidney, lung, liver or intestine become YFP-labelled. These data suggest that Pdgfrα-CreERT2 transgenic mice can be used to achieve robust recombination in OPCs, while having a minimal effect on most PDGFRα+ cell populations outside of the CNS.
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Affiliation(s)
- Megan O’Rourke
- Menzies Institute for Medical Research, University of Tasmania, Liverpool Street, Hobart, Tasmania 7000, Australia
| | - Carlie L. Cullen
- Menzies Institute for Medical Research, University of Tasmania, Liverpool Street, Hobart, Tasmania 7000, Australia
| | - Loic Auderset
- Menzies Institute for Medical Research, University of Tasmania, Liverpool Street, Hobart, Tasmania 7000, Australia
| | - Kimberley A. Pitman
- Menzies Institute for Medical Research, University of Tasmania, Liverpool Street, Hobart, Tasmania 7000, Australia
| | - Daniela Achatz
- Menzies Institute for Medical Research, University of Tasmania, Liverpool Street, Hobart, Tasmania 7000, Australia
| | - Robert Gasperini
- Menzies Institute for Medical Research, University of Tasmania, Liverpool Street, Hobart, Tasmania 7000, Australia
- School of Medicine, University of Tasmania, Liverpool Street, Hobart, Tasmania 7000, Australia
| | - Kaylene M. Young
- Menzies Institute for Medical Research, University of Tasmania, Liverpool Street, Hobart, Tasmania 7000, Australia
- * E-mail:
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27
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Auderset L, Cullen CL, Young KM. Low Density Lipoprotein-Receptor Related Protein 1 Is Differentially Expressed by Neuronal and Glial Populations in the Developing and Mature Mouse Central Nervous System. PLoS One 2016; 11:e0155878. [PMID: 27280679 PMCID: PMC4900551 DOI: 10.1371/journal.pone.0155878] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 05/05/2016] [Indexed: 11/19/2022] Open
Abstract
The low density lipoprotein-receptor related protein 1 (LRP1) is a large endocytic cell surface receptor that is known to interact with a variety of ligands, intracellular adaptor proteins and other cell surface receptors to regulate cellular behaviours ranging from proliferation to cell fate specification, migration, axon guidance, and lipid metabolism. A number of studies have demonstrated that LRP1 is expressed in the brain, yet it is unclear which central nervous system cell types express LRP1 during development and in adulthood. Herein we undertake a detailed study of LRP1 expression within the mouse brain and spinal cord, examining a number of developmental stages ranging from embryonic day 13.5 to postnatal day 60. We report that LRP1 expression in the brain peaks during postnatal development. On a cellular level, LRP1 is expressed by radial glia, neuroblasts, microglia, oligodendrocyte progenitor cells (OPCs), astrocytes and neurons, with the exception of parvalbumin+ interneurons in the cortex. Most cell populations exhibit stable expression of LRP1 throughout development; however, the proportion of OPCs that express LRP1 increases significantly from ~69% at E15.5 to ~99% in adulthood. We also report that LRP1 expression is rapidly lost as OPCs differentiate, and is absent from all oligodendrocytes, including newborn oligodendrocytes. While LRP1 function has been primarily examined in mature neurons, these expression data suggest it plays a more critical role in glial cell regulation-where expression levels are much higher.
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Affiliation(s)
- Loic Auderset
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, 7000, Australia
| | - Carlie L. Cullen
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, 7000, Australia
| | - Kaylene M. Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, 7000, Australia
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28
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Pitman KA, Young KM. Activity-dependent calcium signalling in oligodendrocyte generation. Int J Biochem Cell Biol 2016; 77:30-34. [PMID: 27233230 DOI: 10.1016/j.biocel.2016.05.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [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: 04/08/2016] [Revised: 05/21/2016] [Accepted: 05/23/2016] [Indexed: 11/26/2022]
Abstract
Throughout postnatal life oligodendrocyte progenitor cells proliferate and differentiate into mature myelinating oligodendrocytes in the central nervous system. Neuronal activity is a major external signal controlling this process. Neurotransmitters, or other signalling molecules released in response to neuronal activity, evoke transient increases in intracellular calcium in oligodendrocyte progenitor cells. As calcium can mediate cellular processes, including the transcription of genes involved in oligodendrocyte progenitor cell division and maturation, a rise in intracellular calcium may be a key signal translating changes in neuronal activity into changes in oligodendrocyte progenitor cell behaviour. Here we review recent advances in our understanding of how neuronal activity can evoke calcium signalling in oligodendrocyte progenitor cells.
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Affiliation(s)
- Kimberley A Pitman
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania 7000, Australia
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania 7000, Australia.
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29
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Cullen CL, Young KM. How Does Transcranial Magnetic Stimulation Influence Glial Cells in the Central Nervous System? Front Neural Circuits 2016; 10:26. [PMID: 27092058 PMCID: PMC4820444 DOI: 10.3389/fncir.2016.00026] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 03/23/2016] [Indexed: 12/13/2022] Open
Abstract
Transcranial magnetic stimulation (TMS) is widely used in the clinic, and while it has a direct effect on neuronal excitability, the beneficial effects experienced by patients are likely to include the indirect activation of other cell types. Research conducted over the past two decades has made it increasingly clear that a population of non-neuronal cells, collectively known as glia, respond to and facilitate neuronal signaling. Each glial cell type has the ability to respond to electrical activity directly or indirectly, making them likely cellular effectors of TMS. TMS has been shown to enhance adult neural stem and progenitor cell (NSPC) proliferation, but the effect on cell survival and differentiation is less certain. Furthermore there is limited information regarding the response of astrocytes and microglia to TMS, and a complete paucity of data relating to the response of oligodendrocyte-lineage cells to this treatment. However, due to the critical and yet multifaceted role of glial cells in the central nervous system (CNS), the influence that TMS has on glial cells is certainly an area that warrants careful examination.
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Affiliation(s)
- Carlie L. Cullen
- Menzies Institute for Medical Research, University of TasmaniaHobart, TAS, Australia
| | - Kaylene M. Young
- Menzies Institute for Medical Research, University of TasmaniaHobart, TAS, Australia
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Russell S, Tubbs L, McLelland DJ, LePage V, Young KM, Huber P, Lumsden JS. Amyloid associated with neoplasia in two captive tricolour sharkminnows Balantiocheilus melanopterus Bleeker. J Fish Dis 2015; 38:561-565. [PMID: 25117633 DOI: 10.1111/jfd.12266] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2014] [Revised: 01/05/2014] [Accepted: 04/05/2014] [Indexed: 06/03/2023]
Abstract
Amyloid associated with pancreatic adenocarcinoma was discovered in two captive adult tricolour sharkminnows Balantiocheilus melanopterus Bleeker found dead in a freshwater display. Enlarged abdomens expanded by bloody ascitic fluid and grossly visible masses of abnormal tissue were present surrounding sections of the stomach and intestine. Histologically, the masses were composed of areas of well-organized exocrine pancreatic acini interspersed with cords of poorly differentiated, spindle-shaped cells that compressed and effaced normal parenchyma. These cells possessed small numbers of cytoplasmic zymogen granules; the exocrine nature of these cells was confirmed using transmission electron microscopy (TEM). Fibrovascular connective tissue of the hepatopancreas and mesenteries was expanded by lightly eosinophilic, hyaline, homogeneous acellular material. Similar material greatly expanded the tunica media of large blood vessels in the hepatopancreas. After staining with Congo red or thioflavin T, this material exhibited red-green dichroism under polarized light or bright green fluorescence under ultraviolet light (255 nm), respectively. The non-branching fibrils, of indeterminate length, had an approximate diameter of 10-20 nm using TEM. Although exocrine pancreatic neoplasia is relatively common in fish, the presence of amyloid is not. To our current knowledge, the latter has not yet been described in association with a neoplastic lesion in fish.
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Affiliation(s)
- S Russell
- Novartis Animal Health Inc., Victoria, PEI, Canada
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Brizuela M, Blizzard CA, Chuckowree JA, Dawkins E, Gasperini RJ, Young KM, Dickson TC. The microtubule-stabilizing drug Epothilone D increases axonal sprouting following transection injury in vitro. Mol Cell Neurosci 2015; 66:129-40. [PMID: 25684676 DOI: 10.1016/j.mcn.2015.02.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [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: 12/30/2014] [Revised: 02/03/2015] [Accepted: 02/06/2015] [Indexed: 11/26/2022] Open
Abstract
Neuronal cytoskeletal alterations, in particular the loss and misalignment of microtubules, are considered a hallmark feature of the degeneration that occurs after traumatic brain injury (TBI). Therefore, microtubule-stabilizing drugs are attractive potential therapeutics for use following TBI. The best-known drug in this category is Paclitaxel, a widely used anti-cancer drug that has produced promising outcomes when employed in the treatment of various animal models of nervous system trauma. However, Paclitaxel is not ideal for the treatment of patients with TBI due to its limited blood-brain barrier (BBB) permeability. Herein we have characterized the effect of the brain penetrant microtubule-stabilizing agent Epothilone D (Epo D) on post-injury axonal sprouting in an in vitro model of CNS trauma. Epo D was found to modulate axonal sprout number in a dose dependent manner, increasing the number of axonal sprouts generated post-injury. Elevated sprouting was observed when analyzing the total population of injured neurons, as well as in selective analysis of Thy1-YFP-labeled excitatory neurons. However, we found no effect of Epo D on axonal sprout length or outgrowth speed. These findings indicate that Epo D specifically affects injury-induced axonal sprout generation, but not net growth. Our investigation demonstrates that primary cultures of cortical neurons are tolerant of Epo D exposure, and that Epo D significantly increases their regenerative response following structural injury. Therefore Epo D may be a potent therapeutic for enhancing regeneration following CNS injury. This article is part of a Special Issue entitled 'Traumatic Brain Injury'.
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Affiliation(s)
- Mariana Brizuela
- Menzies Institute for Medical Research Tasmania, University of Tasmania, Hobart, Tasmania 7000, Australia
| | - Catherine A Blizzard
- Menzies Institute for Medical Research Tasmania, University of Tasmania, Hobart, Tasmania 7000, Australia
| | - Jyoti A Chuckowree
- Menzies Institute for Medical Research Tasmania, University of Tasmania, Hobart, Tasmania 7000, Australia
| | - Edgar Dawkins
- Menzies Institute for Medical Research Tasmania, University of Tasmania, Hobart, Tasmania 7000, Australia
| | - Robert J Gasperini
- Menzies Institute for Medical Research Tasmania, University of Tasmania, Hobart, Tasmania 7000, Australia
| | - Kaylene M Young
- Menzies Institute for Medical Research Tasmania, University of Tasmania, Hobart, Tasmania 7000, Australia
| | - Tracey C Dickson
- Menzies Institute for Medical Research Tasmania, University of Tasmania, Hobart, Tasmania 7000, Australia.
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Abstract
Amyloid-β precursor protein (APP) is well studied for its role in Alzheimer disease, although its normal function remains uncertain. It has been reported that APP stimulates the proliferation and neuronal differentiation of neural stem/progenitor cells (NSPCs). In this study we examined the role of APP in NSPC differentiation. To identify proteins that may mediate the effect of APP on NSPC differentiation, we used a gene array approach to find genes whose expression correlated with APP-induced neurogenesis. We found that the expression of neurogenin 2 (Ngn2), a basic helix-loop-helix transcription factor, was significantly down-regulated in NSPCs from APP knock-out mice (APPKO) and increased in APP transgenic (Tg2576) mice. Ngn2 overexpression in APPKO NSPCs promoted neuronal differentiation, whereas siRNA knockdown of Ngn2 expression in wild-type NSPCs decreased neuronal differentiation. The results demonstrate that APP-stimulated neuronal differentiation of NSPCs is mediated by Ngn2.
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Affiliation(s)
- Marta Bolós
- From the Menzies Research Institute Tasmania and
| | - Yanling Hu
- From the Menzies Research Institute Tasmania and
| | | | - Lisa Foa
- From the Menzies Research Institute Tasmania and School of Medicine, University of Tasmania, Hobart, Tasmania 7000, Australia
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Abstract
In this review, we outline the major neural plasticity mechanisms that have been identified in the adult central nervous system (CNS), and offer a perspective on how they regulate CNS function. In particular we examine how myelin plasticity can operate alongside neurogenesis and synaptic plasticity to influence information processing and transfer in the mature CNS.
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Affiliation(s)
- Megan O’Rourke
- Menzies Research Institute Tasmania, University of Tasmania, Hobart 7000, Australia
| | - Robert Gasperini
- Menzies Research Institute Tasmania, University of Tasmania, Hobart 7000, Australia
- The School of Medicine, University of Tasmania, Hobart 7000, Australia
| | - Kaylene M. Young
- Menzies Research Institute Tasmania, University of Tasmania, Hobart 7000, Australia
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Dawkins E, Gasperini R, Hu Y, Cui H, Vincent AJ, Bolós M, Young KM, Foa L, Small DH. The N-terminal fragment of the β-amyloid precursor protein of Alzheimer's disease (N-APP) binds to phosphoinositide-rich domains on the surface of hippocampal neurons. J Neurosci Res 2014; 92:1478-89. [PMID: 24916405 DOI: 10.1002/jnr.23422] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [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: 02/10/2014] [Revised: 04/22/2014] [Accepted: 05/09/2014] [Indexed: 11/11/2022]
Abstract
The function of the β-amyloid precursor protein (APP) of Alzheimer's disease is poorly understood. The secreted ectodomain fragment of APP (sAPPα) can be readily cleaved to produce a small N-terminal fragment (N-APP) that contains heparin-binding and metal-binding domains and that has been found to have biological activity. In the present study, we examined whether N-APP can bind to lipids. We found that N-APP binds selectively to phosphoinositides (PIPs) but poorly to most other lipids. Phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2 )-rich microdomains were identified on the extracellular surface of neurons and glia in primary hippocampal cultures. N-APP bound to neurons and colocalized with PIPs on the cell surface. Furthermore, the binding of N-APP to neurons increased the level of cell-surface PI(4,5)P2 and phosphatidylinositol 3,4,5-trisphosphate. However, PIPs were not the principal cell-surface binding site for N-APP, because N-APP binding to neurons was not inhibited by a short-acyl-chain PIP analogue, and N-APP did not bind to glial cells which also possessed PI(4,5)P2 on the cell surface. The data are explained by a model in which N-APP binds to two distinct components on neurons, one of which is an unidentified receptor and the second of which is a PIP lipid, which binds more weakly to a distinct site within N-APP. Our data provide further support for the idea that N-APP may be an important mediator of APP's biological activity.
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Affiliation(s)
- Edgar Dawkins
- Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia
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35
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Richardson AS, North KE, Graff M, Young KM, Mohlke KL, Lange LA, Lange EM, Harris KM, Gordon-Larsen P. Moderate to vigorous physical activity interactions with genetic variants and body mass index in a large US ethnically diverse cohort. Pediatr Obes 2014; 9:e35-46. [PMID: 23529959 PMCID: PMC3707946 DOI: 10.1111/j.2047-6310.2013.00152.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [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: 08/17/2012] [Revised: 02/06/2013] [Accepted: 01/31/2013] [Indexed: 12/23/2022]
Abstract
BACKGROUND Little is known about the interaction between genetic and behavioural factors during lifecycle risk periods for obesity and how associations vary across race/ethnicity. OBJECTIVE The objective of this study was to examine joint associations of adiposity-related single-nucleotide polymorphisms (SNPs) and moderate to vigorous physical activity (MVPA) with body mass index (BMI) in a diverse adolescent cohort. METHODS Using data from the National Longitudinal Study of Adolescent Health (n = 8113: Wave II 1996; ages 12-21, Wave III; ages 18-27), we assessed interactions of 41 well-established SNPs and MVPA with BMI-for-age Z-scores in European Americans (EA; n = 5077), African-Americans (AA; n = 1736) and Hispanic Americans (HA; n = 1300). RESULTS Of 97 assessed, we found nominally significant SNP-MVPA interactions on BMI-for-age Z-score in EA at GNPDA2 and FTO and in HA at LZTR2/SEC16B. In EA, the estimated effect of the FTO risk allele on BMI-for-age Z-score was lower (β = -0.13; 95% confidence interval [CI]: 0.08, 0.18) in individuals with ≥5 vs. <5 (β = 0.24; CI: 0.16, 0.32) bouts of MVPA per week (P for interaction 0.02). Race/ethnicity-pooled meta-analysis showed nominally significant interactions for SNPs at TFAP2B, POC5 and LYPLAL1. CONCLUSIONS High MVPA may attenuate underlying genetic risk for obesity during adolescence, a high-risk period for adult obesity.
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Affiliation(s)
- AS Richardson
- Carolina Population Center, University of North Carolina, Chapel Hill, North Carolina, USA,Department of Nutrition Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina, USA
| | - KE North
- Carolina Center for Genome Sciences, University of North Carolina, Chapel Hill, North Carolina, USA,Department of Epidemiology, University of North Carolina, Chapel Hill, North Carolina, USA
| | - M Graff
- Carolina Population Center, University of North Carolina, Chapel Hill, North Carolina, USA,Department of Epidemiology, University of North Carolina, Chapel Hill, North Carolina, USA
| | - KM Young
- Carolina Population Center, University of North Carolina, Chapel Hill, North Carolina, USA,Department of Epidemiology, University of North Carolina, Chapel Hill, North Carolina, USA
| | - KL Mohlke
- Carolina Center for Genome Sciences, University of North Carolina, Chapel Hill, North Carolina, USA,Department of Genetics, University of North Carolina, Chapel Hill, North Carolina, USA
| | - LA Lange
- Carolina Center for Genome Sciences, University of North Carolina, Chapel Hill, North Carolina, USA,Department of Genetics, University of North Carolina, Chapel Hill, North Carolina, USA
| | - EM Lange
- Carolina Center for Genome Sciences, University of North Carolina, Chapel Hill, North Carolina, USA,Department of Genetics, University of North Carolina, Chapel Hill, North Carolina, USA
| | - KM Harris
- Carolina Population Center, University of North Carolina, Chapel Hill, North Carolina, USA,Department of Sociology, North Carolina, USA
| | - P Gordon-Larsen
- Carolina Population Center, University of North Carolina, Chapel Hill, North Carolina, USA,Department of Nutrition Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina, USA
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Smerdon JA, Young KM, Lowe M, Hars SS, Yadav TP, Hesp D, Dhanak VR, Tsai AP, Sharma HR, McGrath R. Templated quasicrystalline molecular ordering. Nano Lett 2014; 14:1184-1189. [PMID: 24528205 DOI: 10.1021/nl403947b] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Quasicrystals are materials with long-range ordering but no periodicity. We report scanning tunneling microscopy (STM) observations of quasicrystalline molecular layers on 5-fold quasicrystal surfaces. The molecules adopt positions and orientations on the surface consistent with the quasicrystalline ordering of the substrate. Carbon-60 adsorbs atop sufficiently separated Fe atoms on icosahedral Al-Cu-Fe to form a unique quasicrystalline lattice, whereas further C60 molecules decorate remaining surface Fe atoms in a quasi-degenerate fashion. Pentacene (Pn) adsorbs at 10-fold symmetric points around surface-bisected rhombic triacontahedral clusters in icosahedral Ag-In-Yb. These systems constitute the first demonstrations of quasicrystalline molecular ordering on a template.
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Affiliation(s)
- J A Smerdon
- Jeremiah Horrocks Institute for Mathematics, Physics and Astronomy, University of Central Lancashire , Fylde Rd, Preston, Lancashire PR1 2HE, United Kingdom
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Graff M, North KE, Richardson AS, Young KM, Mohlke KL, Lange LA, Lange EM, Harris KM, Gordon-Larsen P. Screen time behaviours may interact with obesity genes, independent of physical activity, to influence adolescent BMI in an ethnically diverse cohort. Pediatr Obes 2013; 8:e74-9. [PMID: 24039247 PMCID: PMC3838440 DOI: 10.1111/j.2047-6310.2013.00195.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [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: 11/22/2012] [Revised: 06/12/2013] [Accepted: 07/06/2013] [Indexed: 01/27/2023]
Abstract
BACKGROUND There has been little investigation of gene-by-environment interactions related to sedentary behaviour, a risk factor for obesity defined as leisure screen time (ST; i.e. television, video and computer games). OBJECTIVE To test the hypothesis that limiting ST use attenuates the genetic predisposition to increased body mass index (BMI), independent of physical activity. DESIGN Using 7642 wave II participants of the National Longitudinal Study of Adolescent Health, (Add Health; mean = 16.4 years, 52.6% female), we assessed the interaction of ST (h week(-1) ) and 41 established obesity single nucleotide polymorphisms (SNPs) with age- and sex-specific BMI Z-scores in 4788 European-American (EA), 1612 African-American (AA) and 1242 Hispanic American (HA) adolescents. RESULTS Nominally significant SNP*ST interaction were found for FLJ35779 in EA, GNPDA2 in AA and none in HA (EA: beta [SE] = 0.016[0.007]), AA: beta [SE] = 0.016[0.011]) per 7 h week(-1) ST and one risk allele in relation to BMI Z-score. CONCLUSIONS While for two established BMI loci, we find evidence that high levels of ST exacerbate the influence of obesity susceptibility variants on body mass; overall, we do not find strong evidence for interactions between the majority of established obesity loci. However, future studies with larger sample sizes, or that may build on our current study and the growing published literature, are clearly warranted.
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Affiliation(s)
- M Graff
- Department of Epidemiology, University of North Carolina, Chapel
Hill, North Carolina, USA,Carolina Population Center, University of North Carolina, Chapel
Hill, North Carolina, USA
| | - KE North
- Department of Epidemiology, University of North Carolina, Chapel
Hill, North Carolina, USA,Carolina Center for Genome Sciences, University of North Carolina,
Chapel Hill, North Carolina, USA
| | - AS Richardson
- Carolina Population Center, University of North Carolina, Chapel
Hill, North Carolina, USA
| | - K M Young
- Department of Epidemiology, University of North Carolina, Chapel
Hill, North Carolina, USA,Carolina Population Center, University of North Carolina, Chapel
Hill, North Carolina, USA
| | - KL Mohlke
- Carolina Center for Genome Sciences, University of North Carolina,
Chapel Hill, North Carolina, USA,Department of Genetics, University of North Carolina, Chapel Hill,
North Carolina, USA
| | - LA Lange
- Carolina Center for Genome Sciences, University of North Carolina,
Chapel Hill, North Carolina, USA,Department of Genetics, University of North Carolina, Chapel Hill,
North Carolina, USA
| | - EM Lange
- Carolina Center for Genome Sciences, University of North Carolina,
Chapel Hill, North Carolina, USA,Department of Genetics, University of North Carolina, Chapel Hill,
North Carolina, USA
| | - KM Harris
- Carolina Population Center, University of North Carolina, Chapel
Hill, North Carolina, USA,Carolina Center for Genome Sciences, University of North Carolina,
Chapel Hill, North Carolina, USA,Department of Sociology, University of North Carolina, Chapel Hill,
North Carolina, USA
| | - P Gordon-Larsen
- Carolina Population Center, University of North Carolina, Chapel
Hill, North Carolina, USA,Department of Nutrition, University of North Carolina, Chapel Hill,
North Carolina, USA
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38
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Abstract
CNS white matter is subject to a novel form of neural plasticity which has been termed "myelin plasticity". It is well established that oligodendrocyte generation and the addition of new myelin internodes continue throughout normal adulthood. These new myelin internodes maybe required for the de novo myelination of previously unmyelinated axons, myelin sheath replacement, or even myelin remodeling. Each process could alter axonal conduction velocity, but to what end? We review the changes that occur within the white matter over the lifetime, the known regulators and mediators of white matter plasticity in the mature CNS, and the physiological role this plasticity may play in CNS function.
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Affiliation(s)
- S Wang
- Menzies Research Institute Tasmania, University of Tasmania, Hobart 7000, Australia
| | - K M Young
- Menzies Research Institute Tasmania, University of Tasmania, Hobart 7000, Australia.
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39
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Tamura R, Yadav TP, McLeod IM, Hesp D, Young KM, Nakamura T, Nishio K, Dhanak VR, McGrath R, Sharma HR. Scanning tunneling microscopy of a polygrain Al–Pd–Re quasicrystal: study of the relative surface stability. J Phys Condens Matter 2013; 25:395007. [PMID: 24018417 DOI: 10.1088/0953-8984/25/39/395007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Scanning tunneling microscopy and x-ray photoemission spectroscopy on a polygrain icosahedral (i-) Al–Pd–Re quasicrystal (QC) show the formation of the twofold surfaces with symmetry and composition expected from the bulk. The predominant occurrence of the twofold surface on the polygrain i-QC having random grain orientation, as well as preferential formation of terrace edges, kinks and voids along the twofold axes, consistently indicates that the twofold surface, which has the highest atomic density, is the most stable among all the crystallographic planes.
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40
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Small DH, Hu Y, Bolós M, Dawkins E, Foa L, Young KM. β-Amyloid precursor protein: function in stem cell development and Alzheimer's disease brain. NEURODEGENER DIS 2013; 13:96-8. [PMID: 23942027 DOI: 10.1159/000353686] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Accepted: 05/19/2013] [Indexed: 11/19/2022] Open
Abstract
Stem cell therapy may be a suitable approach for the treatment of many neurodegenerative diseases. However, one major impediment to the development of successful cell-based therapies is our limited understanding of the mechanisms that instruct neural stem cell behaviour, such as proliferation and cell fate specification. The β-amyloid precursor protein (APP) of Alzheimer's disease (AD) may play an important role in neural stem cell proliferation and differentiation. Our recent work shows that in vitro, APP stimulates neural stem or progenitor cell proliferation and neuronal differentiation. The effect on proliferation is mediated by an autocrine factor that we have identified as cystatin C. As cystatin C expression is also reported to inhibit the development of amyloid pathology in APP transgenic mice, our finding has implications for the possible use of cystatin C for the therapy of AD.
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Affiliation(s)
- David H Small
- Menzies Research Institute Tasmania and School of Medicine, University of Tasmania, Hobart, Tas., Australia
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41
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Hu Y, Hung AC, Cui H, Dawkins E, Bolós M, Foa L, Young KM, Small DH. Role of cystatin C in amyloid precursor protein-induced proliferation of neural stem/progenitor cells. J Biol Chem 2013; 288:18853-62. [PMID: 23671283 DOI: 10.1074/jbc.m112.443671] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The amyloid precursor protein (APP) is well studied for its role in Alzheimer disease. However, little is known about its normal function. In this study, we examined the role of APP in neural stem/progenitor cell (NSPC) proliferation. NSPCs derived from APP-overexpressing Tg2576 transgenic mice proliferated more rapidly than NSPCs from the corresponding background strain (C57Bl/6xSJL) wild-type mice. In contrast, NSPCs from APP knock-out (APP-KO) mice had reduced proliferation rates when compared with NSPCs from the corresponding background strain (C57Bl/6). A secreted factor, identified as cystatin C, was found to be responsible for this effect. Levels of cystatin C were higher in the Tg2576 conditioned medium and lower in the APP-KO conditioned medium. Furthermore, immunodepletion of cystatin C from the conditioned medium completely removed the ability of the conditioned medium to increase NSPC proliferation. The results demonstrate that APP expression stimulates NSPC proliferation and that this effect is mediated via an increase in cystatin C secretion.
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Affiliation(s)
- Yanling Hu
- Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania 7001, Australia
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42
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Young KM, Psachoulia K, Tripathi RB, Dunn SJ, Cossell L, Attwell D, Tohyama K, Richardson WD. Oligodendrocyte dynamics in the healthy adult CNS: evidence for myelin remodeling. Neuron 2013; 77:873-85. [PMID: 23473318 PMCID: PMC3842597 DOI: 10.1016/j.neuron.2013.01.006] [Citation(s) in RCA: 591] [Impact Index Per Article: 53.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/02/2013] [Indexed: 12/31/2022]
Abstract
Oligodendrocyte precursors (OPs) continue to proliferate and generate myelinating oligodendrocytes (OLs) well into adulthood. It is not known whether adult-born OLs ensheath previously unmyelinated axons or remodel existing myelin. We quantified OP division and OL production in different regions of the adult mouse CNS including the 4-month-old optic nerve, in which practically all axons are already myelinated. Even there, all OPs were dividing and generating new OLs and myelin at a rate higher than can be explained by first-time myelination of naked axons. We conclude that adult-born OLs in the optic nerve are engaged in myelin remodeling, either replacing OLs that die in service or intercalating among existing myelin sheaths. The latter would predict that average internode length should decrease with age. Consistent with that, we found that adult-born OLs elaborated much shorter but many more internodes than OLs generated during early postnatal life.
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Affiliation(s)
- Kaylene M Young
- Wolfson Institute for Biomedical Research and Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK
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Sharma HR, Smerdon JA, Young KM, McGrath R. Epitaxial Bi allotropes on quasicrystal surfaces as templates for adsorption of pentacene and fullerene. J Phys Condens Matter 2012; 24:354012. [PMID: 22898547 DOI: 10.1088/0953-8984/24/35/354012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The growth of Bi on surfaces of Al-based quasicrystals yields a quasicrystalline monolayer which is followed by the formation of crystalline islands of various forms depending on coverage, deposition flux and substrate temperature. We have used the Bi thin films consisting of both crystalline and quasicrystalline allotropes as substrates to study the deposition of C(60) and pentacene molecules. Scanning tunneling microscopy (STM) reveals substrate-dependent differences in molecular adsorption.
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Affiliation(s)
- H R Sharma
- Surface Science Research Centre and Department of Physics, University of Liverpool, Liverpool, UK.
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44
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Abstract
Cycling glial precursors-"NG2-glia"-are abundant in the developing and mature central nervous system (CNS). During development, they generate oligodendrocytes. In culture, they can revert to a multipotent state, suggesting that they might have latent stem cell potential that could be harnessed to treat neurodegenerative disease. This hope has been subdued recently by a series of fate-mapping studies that cast NG2-glia as dedicated oligodendrocyte precursors in the healthy adult CNS-though rare, neuron production in the piriform cortex remains a possibility. Following CNS damage, the repertoire of NG2-glia expands to include Schwann cells and possibly astrocytes-but so far not neurons. This reaffirms the central role of NG2-glia in myelin repair. The realization that oligodendrocyte generation continues throughout normal adulthood has seeded the idea that myelin genesis might also be involved in neural plasticity. We review these developments, highlighting areas of current interest, contention, and speculation.
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Affiliation(s)
- William D Richardson
- Wolfson Institute for Biomedical Research and Research Department of Cell and Developmental Biology, University College London (UCL), UK.
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45
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Baizabal JM, Cano-Martínez A, Valencia C, Santa-Olalla J, Young KM, Rietze RL, Bartlett PF, Covarrubias L. Glial commitment of mesencephalic neural precursor cells expanded as neurospheres precludes their engagement in niche-dependent dopaminergic neurogenesis. Stem Cells Dev 2011; 21:1047-58. [PMID: 21615282 DOI: 10.1089/scd.2011.0241] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Neural precursor cells (NPCs) with high proliferative potential are commonly expanded in vitro as neurospheres. As a population, neurosphere cells show long-term self-renewal capacity and multipotentiality in vitro. These features have led to the assumption that neurosphere cells represent an expansion of the endogenous NPCs residing within the embryonic and adult brain. If this is the case, in principle, bona-fide expansion of endogenous NPCs should not significantly affect their capacity to respond to their original niche of differentiation. To address this issue, we generated primary neurospheres from the dopaminergic niche of the ventral mesencephalon and then transplanted these cells to their original niche within mesencephalic explant cultures. Primary neurosphere cells showed poor capacity to generate dopaminergic neurons in the mesencephalic niche of dopaminergic neurogenesis. Instead, most primary neurosphere cells showed glial commitment as they differentiated into astrocytes in an exclusively neurogenic niche. Subculture of primary cells demonstrated that the neurosphere assay does not amplify niche-responsive dopaminergic progenitors. Further, neurospheres cells were largely unable to acquire the endogenous positional identity within the Nkx6.1(+), Nkx2.2(+), and Pax7(+) domains of mesencephalic explants. Finally, we demonstrate that our observations are not specific for embryonic mesencephalic cells, as NPCs in the adult subventricular zone also showed an intrinsic fate switch from neuronal to glial potential upon neurosphere amplification. Our data suggest that neurosphere formation does not expand the endogenous neurogenic NPCs but rather promotes amplification of gliogenic precursors that do not respond to niche-derived signals of cellular specification and differentiation.
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Affiliation(s)
- José-Manuel Baizabal
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, México
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46
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Reid A, Young KM, Lumsden JS. Rainbow trout Oncorhynchus mykiss ladderlectin, but not intelectin, binds viral hemorrhagic septicemia virus IVb. Dis Aquat Organ 2011; 95:137-143. [PMID: 21848121 DOI: 10.3354/dao02358] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The innate immune system of fish is critical for rapid detection and immediate response to infection, as well as to orchestrate the adaptive branch of the immune system. Rainbow trout Oncorhynchus mykiss ladderlectin and intelectin are plasma pattern recognition receptors (PRR) for bacterial and fungal pathogens of rainbow trout, but their role as PRRs for virus is unknown. Viral hemorrhagic septicemia virus (VHSV) IVb is a recently described fish pathogen in the Great Lakes, and rainbow trout can be experimentally infected. Using an indirect enzyme-linked immunosorbent assay, rainbow trout plasma ladderlectin significantly (p < 0.05) bound purified VHSV while intelectin did not. In addition, plasma ladderlectin but not intelectin was eluted from a VHSV-conjugated Toyopearl column using EDTA. Protein identification was confirmed with polyclonal antiserum used with slot immunoblot, 1-dimensional sodium dodecyl sulphate polyacrylamide electrophoresis, and Western immunoblot.
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Affiliation(s)
- A Reid
- Fish Pathology Laboratory, Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, Ontario N1G 2W1, Canada
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47
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Smerdon JA, Cross N, Dhanak VR, Sharma HR, Young KM, Lograsso TA, Ross AR, McGrath R. Structure and reactivity of Bi allotropes on the fivefold icosahedral Al-Pd-Mn quasicrystal surface. J Phys Condens Matter 2010; 22:345002. [PMID: 21403246 DOI: 10.1088/0953-8984/22/34/345002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The growth of Bi on a pseudomorphic Bi monolayer on the fivefold surface of the icosahedral Al-Pd-Mn quasicrystal has been investigated using low energy electron diffraction and scanning tunnelling microscopy. Initially randomly oriented pseudocubic islands are formed with a preference for an even number of layers. Subsequently a morphological transformation takes place to hexagonal Bi islands, which align along high symmetry directions of the substrate. The Bi flux is found to have a strong effect on which island structure is preferred. When C(60) is adsorbed on the three different allotropes of Bi present in this system, hexagonal C(60) islands are formed in each case. On the pseudocubic and hexagonal islands, the C(60) islands are aligned with the substrate. We discuss the energetic, kinetic and geometrical factors which influence the morphological transformation referred to above.
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Affiliation(s)
- J A Smerdon
- Surface Science Research Centre and Department of Physics, The University of Liverpool, Liverpool, UK
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48
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Carels RA, Wott CB, Young KM, Gumble A, Koball A, Oehlhof MW. Implicit, explicit, and internalized weight bias and psychosocial maladjustment among treatment-seeking adults. Eat Behav 2010; 11:180-5. [PMID: 20434066 DOI: 10.1016/j.eatbeh.2010.03.002] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2009] [Revised: 02/19/2010] [Accepted: 03/05/2010] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Weight bias among weight loss treatment-seeking adults has been understudied. This investigation examined the 1) levels of implicit, explicit, and internalized weight bias among overweight/obese treatment-seeking adults, 2) association between weight bias and psychosocial maladjustment (binge eating, body image, depression), and 3) association between participation in weight loss treatment and changes in weight bias. METHODS Fifty-four overweight and obese individuals (BMI > or = 27) recruited for a weight loss intervention completed measures of depression, body image, binge eating, and implicit, explicit, and internalized weight bias. RESULTS Participants evidenced significant implicit, explicit, and internalized weight bias. Greater weight bias was associated with greater depression, poorer body image, and increased binge eating. Despite significant reductions in negative internalized and explicit weight bias following treatment, weight bias remained strong. CONCLUSIONS Weight bias among treatment-seeking adults is associated with greater psychological maladjustment and may interfere with their ability to achieve optimal health and well-being.
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Affiliation(s)
- R A Carels
- Bowling Green State University, Department of Psychology, Bowling Green, OH 43403, United States.
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49
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Young KM, Mitsumori T, Pringle N, Grist M, Kessaris N, Richardson WD. An Fgfr3-iCreER(T2) transgenic mouse line for studies of neural stem cells and astrocytes. Glia 2010; 58:943-53. [PMID: 20155815 DOI: 10.1002/glia.20976] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The lack of markers for astrocytes, particularly gray matter astrocytes, significantly hinders research into their development and physiological properties. We previously reported that fibroblast growth factor receptor 3 (Fgfr3) is expressed by radial precursors in the ventricular zone of the embryonic neural tube and subsequently by differentiated astrocytes in gray and white matter. Here, we describe an Fgfr3-iCreER(T2) phage artificial chromosome transgenic mouse line that allows efficient tamoxifen-induced Cre recombination in Fgfr3-expressing cells, including radial glial cells in the embryonic neural tube and both fibrous and protoplasmic astrocytes in the mature central nervous system. This mouse strain will therefore be useful for studies of normal astrocyte biology and their responses to CNS injury or disease. In addition, Fgfr3-iCreER(T2) drives Cre recombination in all neurosphere-forming stem cells in the adult spinal cord and at least 90% of those in the adult forebrain subventricular zone. We made use of this to show that there is continuous accumulation of all major interneuron subtypes in the olfactory bulb (OB) from postnatal day 50 (P50) until at least P230 ( approximately 8 months of age). It therefore seems likely that adult-born interneurons integrate into existing circuitry and perform long-term functions in the adult OB.
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Affiliation(s)
- Kaylene M Young
- The Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, United Kingdom
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50
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Friedrichs KR, Thomas C, Plier M, Andrews GA, Chavey PS, Young KM. Evaluation of serum ferritin as a tumor marker for canine histiocytic sarcoma. J Vet Intern Med 2010; 24:904-11. [PMID: 20561186 DOI: 10.1111/j.1939-1676.2010.0543.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Canine histiocytic sarcoma (HS) is an aggressive malignancy. Hyperferritinemia has been documented in dogs with HS and could serve as a tumor marker aiding in diagnosis and treatment. In people, hyperferritinemia is found in inflammatory diseases, liver disease, and hemolysis, and thus may occur in dogs with these conditions. OBJECTIVE To determine if serum ferritin concentration is a tumor marker for canine HS. ANIMALS Dogs with HS (18), inflammatory diseases (20), liver disease (24), immune-mediated hemolytic anemia (IMHA) (15), and lymphoma (23). METHODS Prospective, observational, cohort study: Serum ferritin concentration was measured at initial diagnosis. Parametric methods were used to compare mean log ferritin concentrations among disease categories. Receiver-operating characteristic curves and likelihood ratios were used to evaluate serum ferritin concentration as a tumor marker. RESULTS Varying proportions of dogs with IMHA (94%), HS (89%), liver disease (79%), lymphoma (65%), and inflammatory diseases (40%) had hyperferritinemia. Dogs with IMHA had significantly higher mean ferritin concentration than dogs in all other categories. Dogs with HS had significantly higher mean ferritin concentration than those in the inflammatory disease and lymphoma categories. Mean serum ferritin concentration was not significantly different between dogs with HS and those with liver disease. Decision thresholds were determined to distinguish IMHA and HS from the other diseases associated with hyperferritinemia. CONCLUSION Hyperferritinemia is common in dogs with HS and, after IMHA is ruled out, the degree of hyperferritinemia may be useful in differentiating dogs with HS from dogs with inflammatory diseases, liver disease, and lymphoma.
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Affiliation(s)
- K R Friedrichs
- Department of Pathobiological Sciences, University of Wisconsin School of Veterinary Medicine, Madison, WI 53716, USA.
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