1
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Sundman MH, Avila De Vault BE, Chen AYC, Madhavan L, Fuglevand AJ, Chou YH. The (hyper)excitable brain: what can a ubiquitous TMS measure reveal about cognitive aging? Neurobiol Aging 2023; 132:250-252. [PMID: 37827912 PMCID: PMC10982121 DOI: 10.1016/j.neurobiolaging.2023.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 09/16/2023] [Accepted: 09/18/2023] [Indexed: 10/14/2023]
Affiliation(s)
- Mark H Sundman
- Brain Imaging and TMS Laboratory, Department of Psychology, University of Arizona, Tucson, AZ, USA
| | | | - Allison Yu-Chin Chen
- Brain Imaging and TMS Laboratory, Department of Psychology, University of Arizona, Tucson, AZ, USA
| | - Lalitha Madhavan
- Departments of Neurology and Molecular and Cellular Biology, College of Medicine, University of Arizona, Tucson, AZ, USA; Evelyn F McKnight Brain Institute, Arizona Center on Aging, and BIO5 Institute, University of Arizona, Tucson, AZ, USA
| | - Andrew J Fuglevand
- Departments of Physiology and Neuroscience, College of Medicine, University of Arizona, Tucson, AZ, USA
| | - Ying-Hui Chou
- Brain Imaging and TMS Laboratory, Department of Psychology, University of Arizona, Tucson, AZ, USA; Evelyn F McKnight Brain Institute, Arizona Center on Aging, and BIO5 Institute, University of Arizona, Tucson, AZ, USA.
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2
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Corenblum MJ, McRobbie-Johnson A, Carruth E, Bernard K, Luo M, Mandarino LJ, Peterson S, Sans-Fuentes MA, Billheimer D, Maley T, Eggers ED, Madhavan L. Parallel neurodegenerative phenotypes in sporadic Parkinson's disease fibroblasts and midbrain dopamine neurons. Prog Neurobiol 2023; 229:102501. [PMID: 37451330 DOI: 10.1016/j.pneurobio.2023.102501] [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: 01/23/2023] [Revised: 06/29/2023] [Accepted: 07/10/2023] [Indexed: 07/18/2023]
Abstract
Understanding the mechanisms causing Parkinson's disease (PD) is vital to the development of much needed early diagnostics and therapeutics for this debilitating condition. Here, we report cellular and molecular alterations in skin fibroblasts of late-onset sporadic PD subjects, that were recapitulated in matched induced pluripotent stem cell (iPSC)-derived midbrain dopamine (DA) neurons, reprogrammed from the same fibroblasts. Specific changes in growth, morphology, reactive oxygen species levels, mitochondrial function, and autophagy, were seen in both the PD fibroblasts and DA neurons, as compared to their respective controls. Additionally, significant alterations in alpha synuclein expression and electrical activity were also noted in the PD DA neurons. Interestingly, although the fibroblast and neuronal phenotypes were similar to each other, they differed in their nature and scale. Furthermore, statistical analysis revealed potential novel associations between various clinical measures of the PD subjects and the different fibroblast and neuronal data. In essence, these findings encapsulate spontaneous, in-tandem, disease-related phenotypes in both sporadic PD fibroblasts and iPSC-based DA neurons, from the same patient, and generates an innovative model to investigate PD mechanisms with a view towards rational disease stratification and precision treatments.
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Affiliation(s)
- M J Corenblum
- Department of Neurology, University of Arizona, Tucson, AZ, United States
| | - A McRobbie-Johnson
- Physiological Sciences Graduate Program, University of Arizona, Tucson, AZ, United States
| | - E Carruth
- Physiology Undergraduate Program, University of Arizona, Tucson, AZ, United States
| | - K Bernard
- Physiological Sciences Graduate Program, University of Arizona, Tucson, AZ, United States
| | - M Luo
- Department of Medicine, University of Arizona, Tucson, AZ, United States
| | - L J Mandarino
- Department of Medicine, University of Arizona, Tucson, AZ, United States
| | - S Peterson
- Statistical Consulting Lab, BIO5 Institute, University of Arizona, Tucson, AZ, United States
| | - M A Sans-Fuentes
- Statistical Consulting Lab, BIO5 Institute, University of Arizona, Tucson, AZ, United States
| | - D Billheimer
- Statistical Consulting Lab, BIO5 Institute, University of Arizona, Tucson, AZ, United States
| | - T Maley
- Physiological Sciences Graduate Program, University of Arizona, Tucson, AZ, United States
| | - E D Eggers
- Departments of Physiology and Biomedical Engineering, University of Arizona, Tucson, AZ, United States
| | - L Madhavan
- Department of Neurology, University of Arizona, Tucson, AZ, United States; Evelyn F McKnight Brain Institute and BIO5 Institute, University of Arizona, Tucson, AZ, United States.
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3
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Anandhan A, Nguyen N, Syal A, Dreher LA, Dodson M, Zhang DD, Madhavan L. Erratum to "NRF2 Loss Accentuates Parkinsonian Pathology and Behavioral Dysfunction in Human α-Synuclein Overexpressing Mice". Aging Dis 2023:AD.2023.10917. [PMID: 37728584 DOI: 10.14336/ad.2023.10917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 09/17/2023] [Indexed: 09/21/2023] Open
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4
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Corenblum MJ, McRobbie-Johnson A, Carruth E, Bernard K, Luo M, Mandarino LJ, Peterson S, Billheimer D, Maley T, Eggers ED, Madhavan L. Parallel Neurodegenerative Phenotypes in Sporadic Parkinson's Disease Fibroblasts and Midbrain Dopamine Neurons. bioRxiv 2023:2023.02.10.527867. [PMID: 36798207 PMCID: PMC9934693 DOI: 10.1101/2023.02.10.527867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Understanding the mechanisms causing Parkinson's disease (PD) is vital to the development of much needed early diagnostics and therapeutics for this debilitating condition. Here, we report cellular and molecular alterations in skin fibroblasts of late-onset sporadic PD subjects, that were recapitulated in matched induced pluripotent stem cell (iPSC)-derived midbrain dopamine (DA) neurons, reprogrammed from the same fibroblasts. Specific changes in growth, morphology, reactive oxygen species levels, mitochondrial function, and autophagy, were seen in both the PD fibroblasts and DA neurons, as compared to their respective controls. Additionally, significant alterations in alpha synuclein expression and electrical activity were also noted in the PD DA neurons. Interestingly, although the fibroblast and neuronal phenotypes were similar to each other, they also differed in their nature and scale. Furthermore, statistical analysis revealed novel associations between various clinical measures of the PD subjects and the different fibroblast and neuronal data. In essence, these findings encapsulate spontaneous, in-tandem, disease-related phenotypes in both sporadic PD fibroblasts and iPSC-based DA neurons, from the same patient, and generates an innovative model to investigate PD mechanisms with a view towards rational disease stratification and precision treatments.
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5
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Jandova J, Park S, Corenblum M, Madhavan L, Snell J, Wondrak G. 639 Identification of experimental therapeutics overcoming NRAS-based BRAFi-resistant malignant melanoma targeting brain metastases in a bioluminescent murine model. J Invest Dermatol 2022. [DOI: 10.1016/j.jid.2022.05.650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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6
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Jandova J, Park SL, Corenblum MJ, Madhavan L, Snell JA, Rounds L, Wondrak GT. Mefloquine induces ER stress and apoptosis in BRAFi-resistant A375-BRAF V600E /NRAS Q61K malignant melanoma cells targeting intracranial tumors in a bioluminescent murine model. Mol Carcinog 2022; 61:603-614. [PMID: 35417045 PMCID: PMC9133119 DOI: 10.1002/mc.23407] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [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: 12/23/2021] [Revised: 03/15/2022] [Accepted: 03/27/2022] [Indexed: 02/03/2023]
Abstract
Molecularly targeted therapeutics have revolutionized the treatment of BRAFV600E -driven malignant melanoma, but the rapid development of resistance to BRAF kinase inhibitors (BRAFi) presents a significant obstacle. The use of clinical antimalarials for the investigational treatment of malignant melanoma has shown only moderate promise, attributed mostly to inhibition of lysosomal-autophagic adaptations of cancer cells, but identification of specific antimalarials displaying single-agent antimelanoma activity has remained elusive. Here, we have screened a focused library of clinically used artemisinin-combination therapeutic (ACT) antimalarials for the apoptotic elimination of cultured malignant melanoma cell lines, also examining feasibility of overcoming BRAFi-resistance comparing isogenic melanoma cells that differ only by NRAS mutational status (BRAFi-sensitive A375-BRAFV600E /NRASQ61 vs. BRAFi-resistant A375-BRAFV600E /NRASQ61K ). Among ACT antimalarials tested, mefloquine (MQ) was the only apoptogenic agent causing melanoma cell death at low micromolar concentrations. Comparative gene expression-array analysis (A375-BRAFV600E /NRASQ61 vs. A375-BRAFV600E /NRASQ61K ) revealed that MQ is a dual inducer of endoplasmic reticulum (ER) and redox stress responses that precede MQ-induced loss of viability. ER-trackerTM DPX fluorescence imaging and electron microscopy indicated ER swelling, accompanied by rapid induction of ER stress signaling (phospho-eIF2α, XBP-1s, ATF4). Fluo-4 AM-fluorescence indicated the occurrence of cytosolic calcium overload observable within seconds of MQ exposure. In a bioluminescent murine model employing intracranial injection of A375-Luc2 (BRAFV600E /NRASQ61K ) cells, an oral MQ regimen efficiently antagonized brain tumor growth. Taken together, these data suggest that the clinical antimalarial MQ may be a valid candidate for drug repurposing aiming at chemotherapeutic elimination of malignant melanoma cells, even if metastasized to the brain and BRAFi-resistant.
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Affiliation(s)
- Jana Jandova
- Department of Pharmacology and Toxicology, RK Coit College of Pharmacy & UA Cancer Center, University of Arizona, Tucson, Arizona, USA
| | - Sophia L. Park
- Department of Pharmacology and Toxicology, RK Coit College of Pharmacy & UA Cancer Center, University of Arizona, Tucson, Arizona, USA
| | - Mandi J. Corenblum
- Department of Neurology, Evelyn F McKnight Brain Institute and BIO5 Institute, University of Arizona, Tucson, Arizona, USA
| | - Lalitha Madhavan
- Department of Neurology, Evelyn F McKnight Brain Institute and BIO5 Institute, University of Arizona, Tucson, Arizona, USA
| | - Jeremy A. Snell
- Department of Pharmacology and Toxicology, RK Coit College of Pharmacy & UA Cancer Center, University of Arizona, Tucson, Arizona, USA
| | - Liliana Rounds
- Department of Pharmacology and Toxicology, RK Coit College of Pharmacy & UA Cancer Center, University of Arizona, Tucson, Arizona, USA
| | - Georg T. Wondrak
- Department of Pharmacology and Toxicology, RK Coit College of Pharmacy & UA Cancer Center, University of Arizona, Tucson, Arizona, USA
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7
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Apostol CR, Bernard K, Tanguturi P, Molnar G, Bartlett MJ, Szabò L, Liu C, Ortiz JB, Saber M, Giordano KR, Green TRF, Melvin J, Morrison HW, Madhavan L, Rowe RK, Streicher JM, Heien ML, Falk T, Polt R. Design and Synthesis of Brain Penetrant Glycopeptide Analogues of PACAP With Neuroprotective Potential for Traumatic Brain Injury and Parkinsonism. Front Drug Discov (Lausanne) 2022; 1. [PMID: 35237767 PMCID: PMC8887546 DOI: 10.3389/fddsv.2021.818003] [Citation(s) in RCA: 4] [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] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
There is an unmet clinical need for curative therapies to treat neurodegenerative disorders. Most mainstay treatments currently on the market only alleviate specific symptoms and do not reverse disease progression. The Pituitary adenylate cyclase-activating polypeptide (PACAP), an endogenous neuropeptide hormone, has been extensively studied as a potential regenerative therapeutic. PACAP is widely distributed in the central nervous system (CNS) and exerts its neuroprotective and neurotrophic effects via the related Class B GPCRs PAC1, VPAC1, and VPAC2, at which the hormone shows roughly equal activity. Vasoactive intestinal peptide (VIP) also activates these receptors, and this close analogue of PACAP has also shown to promote neuronal survival in various animal models of acute and progressive neurodegenerative diseases. However, PACAP's poor pharmacokinetic profile (non-linear PK/PD), and more importantly its limited blood-brain barrier (BBB) permeability has hampered development of this peptide as a therapeutic. We have demonstrated that glycosylation of PACAP and related peptides promotes penetration of the BBB and improves PK properties while retaining efficacy and potency in the low nanomolar range at its target receptors. Furthermore, judicious structure-activity relationship (SAR) studies revealed key motifs that can be modulated to afford compounds with diverse selectivity profiles. Most importantly, we have demonstrated that select PACAP glycopeptide analogues (2LS80Mel and 2LS98Lac) exert potent neuroprotective effects and anti-inflammatory activity in animal models of traumatic brain injury and in a mild-toxin lesion model of Parkinson's disease, highlighting glycosylation as a viable strategy for converting endogenous peptides into robust and efficacious drug candidates.
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Affiliation(s)
- Christopher R Apostol
- Department of Chemistry and Biochemistry, BIO5, The University of Arizona, Tucson, AZ, United States
| | - Kelsey Bernard
- Graduate Interdisciplinary Program in Physiological Sciences, The University of Arizona, Tucson, AZ, United States
| | | | - Gabriella Molnar
- Department of Pharmacology, College of Medicine, The University of Arizona, Tucson, AZ, United States
| | - Mitchell J Bartlett
- Department of Neurology, College of Medicine, The University of Arizona, Tucson, AZ, United States
| | - Lajos Szabò
- Department of Chemistry and Biochemistry, BIO5, The University of Arizona, Tucson, AZ, United States
| | - Chenxi Liu
- Department of Chemistry and Biochemistry, BIO5, The University of Arizona, Tucson, AZ, United States
| | - J Bryce Ortiz
- Barrow Neurological Institute at Phoenix Children's Hospital, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States.,Department of Child Health, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States.,Phoenix Veteran Affairs Health Care System, Phoenix, AZ, United States
| | - Maha Saber
- Barrow Neurological Institute at Phoenix Children's Hospital, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States.,Department of Child Health, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States
| | - Katherine R Giordano
- Barrow Neurological Institute at Phoenix Children's Hospital, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States.,Department of Child Health, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States.,Phoenix Veteran Affairs Health Care System, Phoenix, AZ, United States
| | - Tabitha R F Green
- Department of Child Health, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States
| | - James Melvin
- Department of Child Health, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States.,Department of Biological Sciences, University of Bath, Bath, United Kingdom
| | - Helena W Morrison
- College of Nursing, University of Arizona, Tucson, AZ, United States
| | - Lalitha Madhavan
- Graduate Interdisciplinary Program in Physiological Sciences, The University of Arizona, Tucson, AZ, United States.,Department of Neurology, College of Medicine, The University of Arizona, Tucson, AZ, United States
| | - Rachel K Rowe
- Barrow Neurological Institute at Phoenix Children's Hospital, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States.,Department of Child Health, The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, United States.,Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, United States
| | - John M Streicher
- Department of Pharmacology, College of Medicine, The University of Arizona, Tucson, AZ, United States
| | - Michael L Heien
- Department of Chemistry and Biochemistry, BIO5, The University of Arizona, Tucson, AZ, United States
| | - Torsten Falk
- Graduate Interdisciplinary Program in Physiological Sciences, The University of Arizona, Tucson, AZ, United States.,Department of Pharmacology, College of Medicine, The University of Arizona, Tucson, AZ, United States.,Department of Neurology, College of Medicine, The University of Arizona, Tucson, AZ, United States
| | - Robin Polt
- Department of Chemistry and Biochemistry, BIO5, The University of Arizona, Tucson, AZ, United States
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8
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Anandhan A, Nguyen N, Syal A, Dreher LA, Dodson M, Zhang DD, Madhavan L. NRF2 Loss Accentuates Parkinsonian Pathology and Behavioral Dysfunction in Human α-Synuclein Overexpressing Mice. Aging Dis 2021; 12:964-982. [PMID: 34221542 PMCID: PMC8219498 DOI: 10.14336/ad.2021.0511] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [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: 03/06/2021] [Accepted: 05/11/2021] [Indexed: 12/14/2022] Open
Abstract
Nuclear factor (erythroid-derived 2)-like 2 (NRF2) is a central regulator of cellular stress responses and its transcriptional activation promotes multiple cellular defense and survival mechanisms. The loss of NRF2 has been shown to increase oxidative and proteotoxic stress, two key pathological features of neurodegenerative disorders such as Parkinson’s disease (PD). Moreover, compromised redox homeostasis and protein quality control can cause the accumulation of pathogenic proteins, including alpha-synuclein (α-Syn) which plays a key role in PD. However, despite this link, the precise mechanisms by which NRF2 may regulate PD pathology is not clear. In this study, we generated a humanized mouse model to study the importance of NRF2 in the context of α-Syn-driven neuropathology in PD. Specifically, we developed NRF2 knockout and wild-type mice that overexpress human α-Syn (hα-Syn+/Nrf2-/- and hα-Syn+/Nrf2+/+ respectively) and tested changes in their behavior through nest building, challenging beam, and open field tests at three months of age. Cellular and molecular alterations in α-Syn, including phosphorylation and subsequent oligomerization, as well as changes in oxidative stress, inflammation, and autophagy were also assessed across multiple brain regions. It was observed that although monomeric α-Syn levels did not change, compared to their wild-type counterparts, hα-Syn+/Nrf2-/- mice exhibited increased phosphorylation and oligomerization of α-Syn. This was associated with a loss of tyrosine hydroxylase expressing dopaminergic neurons in the substantia nigra, and more pronounced behavioral deficits reminiscent of early-stage PD, in the hα-Syn+/Nrf2-/- mice. Furthermore, hα-Syn+/Nrf2-/- mice showed significantly amplified oxidative stress, greater expression of inflammatory markers, and signs of increased autophagic burden, especially in the midbrain, striatum and cortical brain regions. These results support an important role for NRF2, early in PD progression. More broadly, it indicates NRF2 biology as fundamental to PD pathogenesis and suggests that targeting NRF2 activation may delay the onset and progression of PD.
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Affiliation(s)
- Annadurai Anandhan
- 1Pharmacology and Toxicology, University of Arizona, Tucson, AZ, USA.,2Department of Neurology, University of Arizona, Tucson, AZ, USA
| | - Nhat Nguyen
- 3Physiology Undergraduate Program, Tucson, AZ, USA
| | - Arjun Syal
- 4Neuroscience and Cognitive Science Undergraduate Program, Tucson, AZ, USA
| | - Luke A Dreher
- 5Ecology and Evolutionary Biology Undergraduate Program, Tucson, AZ, USA
| | - Matthew Dodson
- 1Pharmacology and Toxicology, University of Arizona, Tucson, AZ, USA
| | - Donna D Zhang
- 1Pharmacology and Toxicology, University of Arizona, Tucson, AZ, USA
| | - Lalitha Madhavan
- 2Department of Neurology, University of Arizona, Tucson, AZ, USA.,6Evelyn F McKnight Brain Institute and Bio5 Institute, University of Arizona, Tucson, AZ, USA
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9
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Anandhan A, Kirwan KR, Corenblum MJ, Madhavan L. Enhanced NRF2 expression mitigates the decline in neural stem cell function during aging. Aging Cell 2021; 20:e13385. [PMID: 34128307 PMCID: PMC8208782 DOI: 10.1111/acel.13385] [Citation(s) in RCA: 5] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 04/10/2021] [Accepted: 05/05/2021] [Indexed: 12/14/2022] Open
Abstract
Although it is known that aging affects neural stem progenitor cell (NSPC) biology in fundamental ways, the underlying dynamics of this process are not fully understood. Our previous work identified a specific critical period (CP) of decline in NSPC activity and function during middle age (13–15 months), and revealed the reduced expression of the redox‐sensitive transcription factor, NRF2, as a key mediator of this process. Here, we investigated whether augmenting NRF2 expression could potentially mitigate the NSPC decline across the identified CP. NRF2 expression in subventricular zone (SVZ) NSPCs was upregulated via GFP tagged recombinant adeno‐associated viral vectors (AAV‐NRF2‐eGFP), and its cellular and behavioral effects compared to animals that received control vectors (AAV‐eGFP). The vectors were administered into the SVZs of aging rats, at time points either before or after the CP. Results indicate that animals that had received AAV‐NRF2‐eGFP, prior to the CP (11 months of age), exhibited substantially improved behavioral function (fine olfactory discrimination and motor tasks) in comparison to those receiving control viruses. Further analysis revealed that NSPC proliferation, self‐renewal, neurogenesis, and migration to the olfactory bulb had significantly increased upon NRF2 upregulation. On the other hand, increasing NRF2 after the CP (at 20 months of age) produced no notable changes in NSPC activity at either cellular or behavioral levels. These results, for the first time, indicate NRF2 pathway modulation as a means to support NSPC function with age and highlight a critical time‐dependency for activating NRF2 to enhance NSPC function.
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Affiliation(s)
- Annadurai Anandhan
- Department of Neurology University of Arizona Tucson AZ USA
- Pharmacology and Toxicology University of Arizona Tucson AZ USA
| | - Konner R. Kirwan
- Neuroscience and Cognitive Science Undergraduate Program Tucson AZ USA
| | | | - Lalitha Madhavan
- Department of Neurology University of Arizona Tucson AZ USA
- Bio5 Institute University of ArizonaTucsonAZUSA
- Evelyn F McKnight Brain Institute University of Arizona Tucson AZ USA
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10
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Dodson M, Anandhan A, Zhang DD, Madhavan L. An NRF2 Perspective on Stem Cells and Ageing. Front Aging 2021; 2:690686. [PMID: 36213179 PMCID: PMC9536878 DOI: 10.3389/fragi.2021.690686] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Accepted: 06/03/2021] [Indexed: 04/24/2023]
Abstract
Redox and metabolic mechanisms lie at the heart of stem cell survival and regenerative activity. NRF2 is a major transcriptional controller of cellular redox and metabolic homeostasis, which has also been implicated in ageing and lifespan regulation. However, NRF2's role in stem cells and their functioning with age is only just emerging. Here, focusing mainly on neural stem cells, which are core to adult brain plasticity and function, we review recent findings that identify NRF2 as a fundamental player in stem cell biology and ageing. We also discuss NRF2-based molecular programs that may govern stem cell state and function with age, and implications of this for age-related pathologies.
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Affiliation(s)
- Matthew Dodson
- Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ, United States
| | - Annadurai Anandhan
- Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ, United States
- Department of Neurology, University of Arizona, Tucson, AZ, United States
| | - Donna D. Zhang
- Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ, United States
| | - Lalitha Madhavan
- Department of Neurology, University of Arizona, Tucson, AZ, United States
- Evelyn F. McKnight Brain Institute and Bio5 Institute, University of Arizona, Tucson, AZ, United States
- *Correspondence: Lalitha Madhavan,
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11
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Abstract
NRF2, a transcription factor that has been deemed the master regulator of cellular redox homeostasis, declines with age. NRF2 transcriptionally upregulates genes that combat oxidative stress; therefore, loss of NRF2 allows oxidative stress to go unmitigated and drive the aging phenotype. Oxidative stress is a common theme among the key features associated with the aging process, collectively referred to as the "Hallmarks of Aging", as it disrupts proteostasis, alters genomic stability, and leads to cell death. In this review, we outline the role that oxidative stress and the reduction of NRF2 play in each of the Hallmarks of Aging, including how they contribute to the onset of neurodegenerative disorders, cancer, and other age-related pathologies.
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Affiliation(s)
- Cody J Schmidlin
- Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ, USA
| | - Matthew B Dodson
- Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ, USA
| | - Lalitha Madhavan
- Department of Neurology, University of Arizona, Tucson, AZ, USA; Evelyn F McKnight Brain institute and Center for Innovation in Brain Science, University of Arizona, Tucson, AZ, USA
| | - Donna D Zhang
- Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ, USA; University of Arizona Cancer Center, University of Arizona, Tucson, AZ, USA.
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12
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Ray S, Corenblum MJ, Anandhan A, Reed A, Ortiz FO, Zhang DD, Barnes CA, Madhavan L. A Role for Nrf2 Expression in Defining the Aging of Hippocampal Neural Stem Cells. Cell Transplant 2018; 27:589-606. [PMID: 29871525 PMCID: PMC6041888 DOI: 10.1177/0963689718774030] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [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] [Indexed: 11/17/2022] Open
Abstract
Redox mechanisms are emerging as essential to stem cell function given their capacity to
influence a number of important signaling pathways governing stem cell survival and
regenerative activity. In this context, our recent work identified the reduced expression
of nuclear factor (erythroid-derived 2)-like 2, or Nrf2, in mediating the decline in
subventricular zone neural stem progenitor cell (NSPC) regeneration during aging. Since
Nrf2 is a major transcription factor at the heart of cellular redox regulation and
homeostasis, the current study investigates the role that it may play in the aging of
NSPCs that reside within the other major mammalian germinal niche located in the
subgranular zone (SGZ) of the dentate gyrus (DG) of the hippocampus. Using rats from
multiple aging stages ranging from newborn to old age, and aging Nrf2 knockout mice, we
first determined that, in contrast with subventricular zone (SVZ) NSPCs, Nrf2 expression
does not significantly affect overall DG NSPC viability with age. However, DG NSPCs
resembled SVZ stem cells, in that Nrf2 expression controlled their proliferation and the
balance of neuronal versus glial differentiation particularly in relation to a specific
critical period during middle age. Also, importantly, this Nrf2-based control of NSPC
regeneration was found to impact functional neurogenesis-related hippocampal behaviors,
particularly in the Morris water maze and in pattern separation tasks. Furthermore, the
enrichment of the hippocampal environment via the transplantation of Nrf2-overexpressing
NSPCs was able to mitigate the age-related decline in DG stem cell regeneration during the
critical middle-age period, and significantly improved pattern separation abilities. In
summary, these results emphasize the importance of Nrf2 in DG NSPC regeneration, and
support Nrf2 upregulation as a potential approach to advantageously modulate DG NSPC
activity with age.
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Affiliation(s)
- S Ray
- 1 Department of Neurology, University of Arizona, Tucson, AZ, USA.,2 Undergraduate Biology Research Program, University of Arizona, Tucson, AZ, USA.,3 Neuroscience and Cognitive Science Undergraduate Program, Tucson, AZ, USA
| | - M J Corenblum
- 1 Department of Neurology, University of Arizona, Tucson, AZ, USA
| | - A Anandhan
- 1 Department of Neurology, University of Arizona, Tucson, AZ, USA
| | - A Reed
- 1 Department of Neurology, University of Arizona, Tucson, AZ, USA.,3 Neuroscience and Cognitive Science Undergraduate Program, Tucson, AZ, USA
| | - F O Ortiz
- 1 Department of Neurology, University of Arizona, Tucson, AZ, USA.,3 Neuroscience and Cognitive Science Undergraduate Program, Tucson, AZ, USA
| | - D D Zhang
- 4 Pharmacology and Toxicology, University of Arizona, Tucson, AZ, USA
| | - C A Barnes
- 5 Departments of Psychology & Neuroscience, University of Arizona, Tucson, AZ, USA.,6 Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ, USA
| | - L Madhavan
- 1 Department of Neurology, University of Arizona, Tucson, AZ, USA.,6 Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ, USA
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13
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Teves JMY, Bhargava V, Kirwan KR, Corenblum MJ, Justiniano R, Wondrak GT, Anandhan A, Flores AJ, Schipper DA, Khalpey Z, Sligh JE, Curiel-Lewandrowski C, Sherman SJ, Madhavan L. Parkinson's Disease Skin Fibroblasts Display Signature Alterations in Growth, Redox Homeostasis, Mitochondrial Function, and Autophagy. Front Neurosci 2018; 11:737. [PMID: 29379409 PMCID: PMC5770791 DOI: 10.3389/fnins.2017.00737] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [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: 08/25/2017] [Accepted: 12/18/2017] [Indexed: 12/27/2022] Open
Abstract
The discovery of biomarkers for Parkinson's disease (PD) is challenging due to the heterogeneous nature of this disorder, and a poor correlation between the underlying pathology and the clinically expressed phenotype. An ideal biomarker would inform on PD-relevant pathological changes via an easily assayed biological characteristic, which reliably tracks clinical symptoms. Human dermal (skin) fibroblasts are accessible peripheral cells that constitute a patient-specific system, which potentially recapitulates the PD chronological and epigenetic aging history. Here, we compared primary skin fibroblasts obtained from individuals diagnosed with late-onset sporadic PD, and healthy age-matched controls. These fibroblasts were studied from fundamental viewpoints of growth and morphology, as well as redox, mitochondrial, and autophagic function. It was observed that fibroblasts from PD subjects had higher growth rates, and appeared distinctly different in terms of morphology and spatial organization in culture, compared to control cells. It was also found that the PD fibroblasts exhibited significantly compromised mitochondrial structure and function when assessed via morphological and oxidative phosphorylation assays. Additionally, a striking increase in baseline macroautophagy levels was seen in cells from PD subjects. Exposure of the skin fibroblasts to physiologically relevant stress, specifically ultraviolet irradiation (UVA), further exaggerated the autophagic dysfunction in the PD cells. Moreover, the PD fibroblasts accumulated higher levels of reactive oxygen species (ROS) coupled with lower cell viability upon UVA treatment. In essence, these studies highlight primary skin fibroblasts as a patient-relevant model that captures fundamental PD molecular mechanisms, and supports their potential utility to develop diagnostic and prognostic biomarkers for the disease.
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Affiliation(s)
- Joji M. Y. Teves
- Graduate Interdisciplinary Program in Applied Biosciences, University of Arizona, Tucson, AZ, United States
| | - Vedanshi Bhargava
- Neuroscience and Cognitive Science Undergraduate Program, Undergraduate Biology Research Program, University of Arizona, Tucson, AZ, United States
| | - Konner R. Kirwan
- Neuroscience and Cognitive Science Undergraduate Program, Undergraduate Biology Research Program, University of Arizona, Tucson, AZ, United States
| | - Mandi J. Corenblum
- Department of Neurology, University of Arizona, Tucson, AZ, United States
| | - Rebecca Justiniano
- Pharmacology and Toxicology, University of Arizona, Tucson, AZ, United States
| | - Georg T. Wondrak
- Pharmacology and Toxicology, University of Arizona, Tucson, AZ, United States
| | - Annadurai Anandhan
- Department of Neurology, University of Arizona, Tucson, AZ, United States
| | - Andrew J. Flores
- Graduate Interdisciplinary Program in Physiological Sciences, University of Arizona, Tucson, AZ, United States
| | - David A. Schipper
- Department of Surgery, University of Arizona, Tucson, AZ, United States
| | - Zain Khalpey
- Department of Surgery, University of Arizona, Tucson, AZ, United States
| | - James E. Sligh
- Department of Medicine, University of Arizona, Tucson, AZ, United States
| | | | - Scott J. Sherman
- Department of Neurology, University of Arizona, Tucson, AZ, United States
| | - Lalitha Madhavan
- Department of Neurology, University of Arizona, Tucson, AZ, United States,The Evelyn F McKnight Brain Institute, University of Arizona, Tucson, AZ, United States,*Correspondence: Lalitha Madhavan
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14
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Corenblum MJ, Madhavan L. Small-scale Propagation of Human iPSCs in Serum-free Conditions for Routine Immunocytochemical Characterization. J Vis Exp 2017. [PMID: 28287577 DOI: 10.3791/55260] [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] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
There is great interest in utilizing human induced pluripotent stem cells (hiPSCs) for disease modeling and cell therapeutics due to their patient specificity and characteristic stemness. However, the pluripotency of iPSCs, which is essential to their functionality, must be confirmed before these cells can be used in such applications. While a rigorous characterization of iPSCs, through different cellular and functional assays is necessary to establish their pluripotency, routine assessment of pluripotency maintenance can be achieved more simply and effectively through immunocytochemical techniques. Here, we present a systematic protocol for culturing hiPSCs, in a scaled-down manner, to particularly facilitate the verification of their pluripotent state using immunocytochemistry. More specifically, this methodology encompasses an efficient and cost-effective means of growing iPSCs in serum-free conditions and plating them on small chamber slides or glass coverslips ideal for immunocytochemistry.
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15
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Corenblum MJ, Ray S, Remley QW, Long M, Harder B, Zhang DD, Barnes CA, Madhavan L. Reduced Nrf2 expression mediates the decline in neural stem cell function during a critical middle-age period. Aging Cell 2016; 15:725-36. [PMID: 27095375 PMCID: PMC4933666 DOI: 10.1111/acel.12482] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/21/2016] [Indexed: 12/14/2022] Open
Abstract
Although it is known that the regenerative function of neural stem/progenitor cells (NSPCs) declines with age, causal mechanisms underlying this phenomenon are not understood. Here, we systematically analyze subventricular zone (SVZ) NSPCs, in various groups of rats across the aging spectrum, using in vitro and in vivo histological and behavioral techniques. These studies indicate that although NSPC function continuously declines with advancing age, there is a critical time period during middle age (13–15 months) when a striking reduction in NSPC survival and regeneration (proliferation and neuronal differentiation) occurs. The studies also indicate that this specific temporal pattern of NSPC deterioration is functionally relevant at a behavioral level and correlates with the decreasing expression of the redox‐sensitive transcription factor, Nrf2, in the NSPCs. When Nrf2 expression was suppressed in ‘young’ NSPCs, using short interfering RNAs, the survival and regeneration of the NSPCs was significantly compromised and mirrored ‘old’ NSPCs. Conversely, Nrf2 overexpression in ‘old’ NSPCs rendered them similar to ‘young’ NSPCs, and they showed increased survival and regeneration. Furthermore, examination of newborn Nrf2 knockout (Nrf2 −/−) mice revealed a lower number of SVZ NSPCs in these animals, when compared to wild‐type controls. In addition, the proliferative and neurogenic potential of the NSPCs was also compromised in the Nrf2−/− mice. These results identify a novel regulatory role for Nrf2 in NSPC function during aging and have important implications for developing NSPC‐based strategies to support healthy aging and to treat age‐related neurodegenerative disorders.
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Affiliation(s)
| | - Sneha Ray
- Department of Neurology University of Arizona Tucson AZ USA
- Neuroscience and Cognitive Science Undergraduate Program Undergraduate Biology Research Program University of Arizona Tucson AZ USA
| | - Quentin W. Remley
- Department of Neurology University of Arizona Tucson AZ USA
- Neuroscience and Cognitive Science Undergraduate Program Undergraduate Biology Research Program University of Arizona Tucson AZ USA
| | - Min Long
- Pharmacology and Toxicology University of Arizona Tucson AZ USA
| | - Bryan Harder
- Pharmacology and Toxicology University of Arizona Tucson AZ USA
| | - Donna D. Zhang
- Pharmacology and Toxicology University of Arizona Tucson AZ USA
| | - Carol A. Barnes
- Department of Neurology University of Arizona Tucson AZ USA
- Departments of Psychology & Neuroscience University of Arizona Tucson AZ USA
- Evelyn F McKnight Brain Institute University of Arizona Tucson AZ USA
| | - Lalitha Madhavan
- Department of Neurology University of Arizona Tucson AZ USA
- Evelyn F McKnight Brain Institute University of Arizona Tucson AZ USA
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16
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Corenblum MJ, Flores AJ, Badowski M, Harris DT, Madhavan L. Systemic human CD34(+) cells populate the brain and activate host mechanisms to counteract nigrostriatal degeneration. Regen Med 2016; 10:563-77. [PMID: 26237701 DOI: 10.2217/rme.15.32] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
AIM Here we investigated the neuroprotective potential of systemic CD34(+) human cord blood cells (hCBCs) in a 6-hydroxydopamine rat model of Parkinson's disease. METHODS Purified CD34(+) hCBCs were intravenously administered to rats subjected to 6-hydroxydopamine 24 h earlier, and behavioral and immunohistological analysis performed. RESULTS CD34(+) hCBC administration significantly prevented host nigrostriatal degeneration inducing behavioral recovery in treated rats. Although donor hCBCs did not differentiate into neural phenotypes, they stimulated the production of new neuroblasts and angiogenesis, and reduced gliosis in recipient animals. Importantly, surviving donor hCBCs were identified, and their tissue distribution pattern correlated with the observed therapeutic effects. CONCLUSION Peripherally applied CD34(+) hCBCs can migrate into brain tissues and elicit host-based protective mechanisms to support the survival of midbrain dopamine neurons.
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Affiliation(s)
- Mandi J Corenblum
- Department of Neurology, University of Arizona, 1501, N Campbell Ave., Tucson, AZ 85724, USA
| | - Andrew J Flores
- Department of Neurology, University of Arizona, 1501, N Campbell Ave., Tucson, AZ 85724, USA.,Physiological Sciences Graduate Program, University of Arizona, Tucson, AZ 85724, USA
| | - Michael Badowski
- Department of Immunobiology, University of Arizona, Tucson, AZ 85724-5221, USA
| | - David T Harris
- Department of Immunobiology, University of Arizona, Tucson, AZ 85724-5221, USA
| | - Lalitha Madhavan
- Department of Neurology, University of Arizona, 1501, N Campbell Ave., Tucson, AZ 85724, USA
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17
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Umashankar A, Corenblum MJ, Ray S, Valdez M, Yoshimaru ES, Trouard TP, Madhavan L. Effects of the iron oxide nanoparticle Molday ION Rhodamine B on the viability and regenerative function of neural stem cells: relevance to clinical translation. Int J Nanomedicine 2016; 11:1731-48. [PMID: 27175074 PMCID: PMC4854246 DOI: 10.2147/ijn.s102006] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
An essential component of developing successful neural stem cell (NSC)-based therapies involves the establishment of methodologies to noninvasively monitor grafted NSCs within brain tissues in real time. In this context, ex vivo labeling with ultrasmall superparamagnetic iron oxide (USPIO) particles has been shown to enable efficient tracking of transplanted NSCs via magnetic resonance imaging (MRI). However, whether and how USPIO labeling affects the intrinsic biology of NSCs is not thoroughly understood, and remains an active area of investigation. Here, we perform a comprehensive examination of rat NSC survival and regenerative function upon labeling with the USPIO, Molday ION Rhodamine B (MIRB), which allows for dual magnetic resonance and optical imaging. After optimization of labeling efficiency, two specific doses of MIRB (20 and 50 μg/mL) were chosen and were followed for the rest of the study. We observed that both MIRB doses supported the robust detection of NSCs, over an extended period of time in vitro and in vivo after transplantation into the striata of host rats, using MRI and post hoc fluorescence imaging. Both in culture and after neural transplantation, the higher 50 μg/mL MIRB dose significantly reduced the survival, proliferation, and differentiation rate of the NSCs. Interestingly, although the lower 20 μg/mL MIRB labeling did not produce overtly negative effects, it increased the proliferation and glial differentiation of the NSCs. Additionally, application of this dose also changed the morphological characteristics of neurons and glia produced after NSC differentiation. Importantly, the transplantation of NSCs labeled with either of the two MIRB doses upregulated the immune response in recipient animals. In particular, in animals receiving the 50 μg/mL MIRB-labeled NSCs, this immune response consisted of an increased number of CD68+-activated microglia, which appeared to have phagocytosed MIRB particles and cells contributing to an exaggerated MRI signal dropout in the animals. Overall, these results indicate that although USPIO particles, such as MIRB, may have advantageous labeling and magnetic resonance-sensitive features for NSC tracking, a further examination of their effects might be necessary before they can be used in clinical scenarios of cell-based transplantation.
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Affiliation(s)
- Abhishek Umashankar
- Department of Neurology, University of Arizona, Tucson, AZ, USA; Neuroscience and Cognitive Science Undergraduate Program, Undergraduate Biology Research Program, University of Arizona, Tucson, AZ, USA
| | | | - Sneha Ray
- Department of Neurology, University of Arizona, Tucson, AZ, USA; Neuroscience and Cognitive Science Undergraduate Program, Undergraduate Biology Research Program, University of Arizona, Tucson, AZ, USA
| | - Michel Valdez
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ, USA
| | - Eriko S Yoshimaru
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ, USA
| | - Theodore P Trouard
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ, USA; Evelyn F McKnight Brain Institute, University of Arizona, Tucson, AZ, USA
| | - Lalitha Madhavan
- Department of Neurology, University of Arizona, Tucson, AZ, USA; Evelyn F McKnight Brain Institute, University of Arizona, Tucson, AZ, USA
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18
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Madhavan L, Daley BF, Davidson BL, Boudreau RL, Lipton JW, Cole-Strauss A, Steece-Collier K, Collier TJ. Sonic Hedgehog Controls the Phenotypic Fate and Therapeutic Efficacy of Grafted Neural Precursor Cells in a Model of Nigrostriatal Neurodegeneration. PLoS One 2015; 10:e0137136. [PMID: 26340267 PMCID: PMC4560385 DOI: 10.1371/journal.pone.0137136] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [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: 04/20/2015] [Accepted: 08/12/2015] [Indexed: 02/06/2023] Open
Abstract
The expression of soluble growth and survival promoting factors by neural precursor cells (NPCs) is suggested to be a prominent mechanism underlying the protective and regenerative effects of these cells after transplantation. Nevertheless, how and to what extent specific NPC-expressed factors contribute to therapeutic effects is not well understood. Using RNA silencing, the current study investigated the roles of two donor NPC molecules, namely glial cell-line derived neurotrophic factor (GDNF) and sonic hedgehog (SHH), in the protection of substantia nigra dopamine neurons in rats treated with 6-hydroxydopamine (6-OHDA). Analyses indicate that as opposed to the knock-down of GDNF, SHH inhibition caused a profound decline in nigrostriatal neuroprotection. Further, SHH silencing also curbed endogenous neurogenesis and the migration of host brdU+/dcx+ neural precursors into the striatum, which was present in the animals receiving control or GDNF silenced NPCs. A change in graft phenotype, mainly reflected by a reduced proportion of undifferentiated nestin+ cells, as well as a significantly greater host microglial activity, suggested an important role for these processes in the attenuation of neuroprotection and neurogenesis upon SHH silencing. Overall these studies reveal core mechanisms fundamental to grafted NPC-based therapeutic effects, and delineate the particular contributions of two graft-expressed molecules, SHH and GDNF, in mediating midbrain dopamine neuron protection, and host plasticity after NPC transplantation.
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Affiliation(s)
- Lalitha Madhavan
- Department of Neurology, University of Arizona, Tucson, Arizona, 85724, United States of America
- * E-mail:
| | - Brian F. Daley
- Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, Michigan, 49503, United States of America
| | - Beverly L. Davidson
- Center for Cell and Molecular Therapy, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, 19104, United States of America
| | - Ryan L. Boudreau
- Department of Internal Medicine, University of Iowa, Iowa City, Iowa, 52242, United States of America
| | - Jack W. Lipton
- Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, Michigan, 49503, United States of America
| | - Allyson Cole-Strauss
- Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, Michigan, 49503, United States of America
| | - Kathy Steece-Collier
- Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, Michigan, 49503, United States of America
| | - Timothy J. Collier
- Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, Michigan, 49503, United States of America
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19
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Paumier KL, Sortwell CE, Madhavan L, Terpstra B, Daley BF, Collier TJ. Tricyclic antidepressant treatment evokes regional changes in neurotrophic factors over time within the intact and degenerating nigrostriatal system. Exp Neurol 2015; 266:11-21. [PMID: 25681575 DOI: 10.1016/j.expneurol.2015.02.005] [Citation(s) in RCA: 20] [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] [Received: 11/04/2014] [Revised: 01/07/2015] [Accepted: 02/04/2015] [Indexed: 01/16/2023]
Abstract
In addition to alleviating depression, trophic responses produced by antidepressants may regulate neural plasticity in the diseased brain, which not only provides symptomatic benefit but also potentially slows the rate of disease progression in Parkinson's disease (PD). Recent in vitro and in vivo data provide evidence that neurotrophic factors such as brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) may be key mediators of the therapeutic response to antidepressants. As such, we conducted a cross-sectional time-course study to determine whether antidepressant-mediated changes in neurotrophic factors occur in relevant brain regions in response to amitriptyline (AMI) treatment before and after intrastriatal 6-hydroxydopamine (6OHDA). Adult male Wistar rats were divided into seven cohorts and given daily injections (i.p.) of AMI (5mg/kg) or saline throughout the duration of the study. In parallel, various cohorts of intact or parkinsonian animals were sacrificed at specific time points to determine the impact of AMI treatment on trophic factor levels in the intact and degenerating nigrostriatal system. The left and right hemispheres of the substantia nigra, striatum, frontal cortex, piriform cortex, hippocampus, and anterior cingulate cortex were dissected, and BDNF and GDNF levels were measured with ELISA. Results show that chronic AMI treatment elicits effects in multiple brain regions and differentially regulates levels of BDNF and GDNF depending on the region. Additionally, AMI halts the progressive degeneration of dopamine (DA) neurons elicited by an intrastriatal 6-OHDA lesion. Taken together, these results suggest that AMI treatment elicits significant trophic changes important to DA neuron survival within both the intact and degenerating nigrostriatal system.
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Affiliation(s)
- Katrina L Paumier
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA.
| | - Caryl E Sortwell
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA
| | | | - Brian Terpstra
- The Parkinson's Disease Rehabilitation Institute, Cincinnati, OH, USA
| | - Brian F Daley
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA
| | - Timothy J Collier
- Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI, USA
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20
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Paumier KL, Siderowf AD, Auinger P, Oakes D, Madhavan L, Espay AJ, Revilla FJ, Collier TJ. Tricyclic antidepressants delay the need for dopaminergic therapy in early Parkinson's disease. Mov Disord 2012; 27:880-7. [PMID: 22555881 DOI: 10.1002/mds.24978] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Revised: 02/01/2012] [Accepted: 02/26/2012] [Indexed: 12/13/2022] Open
Abstract
This study examined whether antidepressants delay the need for dopaminergic therapy or change the degree of motor impairment and disability in a population of early Parkinson's disease (PD) patients. Preclinical studies have indicated that antidepressants modulate signaling pathways involved in cell survival and plasticity, suggesting they may serve to both treat PD-associated depression and slow disease progression. A patient-level meta-analysis included 2064 patients from the treatment and placebo arms of the following trials: FS1, FS-TOO, ELLDOPA, QE2, TEMPO, and PRECEPT. Depression severity was determined at baseline, and antidepressant use was reported in a medication log each visit. Kaplan-Meier curves and time-dependent Cox proportional hazards models determined associations between depression severity and antidepressant use with the primary outcome, time to initiation of dopaminergic therapy. ANCOVAs determined associations with the secondary outcome, degree of motor impairment and disability, reported as annualized change in UPDRS scores from baseline to final visit. When controlling for baseline depression, the initiation of dopaminergic therapy was delayed for subjects taking tricyclic antidepressants compared with those not taking antidepressants. No significant differences were found in UPDRS scores for subjects taking antidepressants compared with those not taking antidepressants. Tricyclic antidepressants are associated with a delay in reaching the end point of need to start dopaminergic therapy. The lack of change in overall UPDRS scores suggests the delay was not attributable to symptomatic effects.
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Affiliation(s)
- Katrina L Paumier
- Department of Neurology, University of Cincinnati, Cincinnati, Ohio, USA
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21
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Madhavan L, Daley BF, Sortwell CE, Collier TJ. Endogenous neural precursors influence grafted neural stem cells and contribute to neuroprotection in the parkinsonian rat. Eur J Neurosci 2012; 35:883-95. [PMID: 22417168 DOI: 10.1111/j.1460-9568.2012.08019.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Neuroprotective and neurorescue effects after neural stem/precursor cell (NPC) transplantation have been reported, but the mechanisms underlying such phenomena are not well understood. Our recent findings in a rat Parkinson's disease (PD) model indicate that transplantation of NPCs before a 6-hydroxydopamine (6-OHDA) insult can result in nigrostriatal protection which is associated with endogenous NPC proliferation, migration and neurogenesis. Here, we sought to determine whether the observed endogenous NPC response (i) contributes to transplanted NPC-mediated neuroprotection; and/or (ii) affects graft phenotype and function. Host Fischer 344 rats were administered the antimitotic agent cytosine-β-d-arabinofuranoside (Ara-C) to eliminate actively proliferating endogenous neural precursors before being transplanted with NPCs and treated with 6-OHDA to induce nigrostriatal degeneration. Behavioral and histological analyses demonstrate that the neuroprotective response observed in NPC transplanted animals which had not received Ara-C was significantly attenuated in animals which did receive pre-transplant Ara-C. Also, while grafts in Ara-C-treated animals showed no decrease in cell number, they exhibited significantly reduced expression of the neural stem cell regulators nestin and sonic hedgehog. In addition, inhibition of the endogenous NPC response resulted in an exaggerated host glial reaction. Overall, the study establishes for the first time that endogenous NPCs contribute to transplanted NPC-mediated therapeutic effects by affecting both grafted and mature host cells in unique ways. Thus, both endogenous and transplanted NPCs are important in creating an environment suitable for neural protection and rescue, and harnessing their synergistic interaction may lead to the optimization of cell-based therapies for PD.
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Affiliation(s)
- Lalitha Madhavan
- Department of Neurology, University of Cincinnati, Cincinnati, OH, USA
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22
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Gombash SE, Lipton JW, Collier TJ, Madhavan L, Steece-Collier K, Cole-Strauss A, Terpstra BT, Spieles-Engemann AL, Daley BF, Wohlgenant SL, Thompson VB, Manfredsson FP, Mandel RJ, Sortwell CE. Striatal pleiotrophin overexpression provides functional and morphological neuroprotection in the 6-hydroxydopamine model. Mol Ther 2011; 20:544-54. [PMID: 22008908 DOI: 10.1038/mt.2011.216] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Neurotrophic factors are integrally involved in the development of the nigrostriatal system and in combination with gene therapy, possess great therapeutic potential for Parkinson's disease (PD). Pleiotrophin (PTN) is involved in the development, maintenance, and repair of the nigrostriatal dopamine (DA) system. The present study examined the ability of striatal PTN overexpression, delivered via psueudotyped recombinant adeno-associated virus type 2/1 (rAAV2/1), to provide neuroprotection and functional restoration from 6-hydroxydopamine (6-OHDA). Striatal PTN overexpression led to significant neuroprotection of tyrosine hydroxylase immunoreactive (THir) neurons in the substantia nigra pars compacta (SNpc) and THir neurite density in the striatum, with long-term PTN overexpression producing recovery from 6-OHDA-induced deficits in contralateral forelimb use. Transduced striatal PTN levels were increased threefold compared to adult striatal PTN expression and approximated peak endogenous developmental levels (P1). rAAV2/1 vector exclusively transduced neurons within the striatum and SNpc with approximately half the total striatal volume routinely transduced using our injection parameters. Our results indicate that striatal PTN overexpression can provide neuroprotection for the 6-OHDA lesioned nigrostriatal system based upon morphological and functional measures and that striatal PTN levels similar in magnitude to those expressed in the striatum during development are sufficient to provide neuroprotection from Parkinsonian insult.
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Affiliation(s)
- Sara E Gombash
- Department of Neurology, University of Cincinnati, Cincinnati, Ohio, USA
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23
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Kordower JH, Dodiya HB, Kordower AM, Terpstra B, Paumier K, Madhavan L, Sortwell C, Steece-Collier K, Collier TJ. Transfer of host-derived α synuclein to grafted dopaminergic neurons in rat. Neurobiol Dis 2011; 43:552-7. [PMID: 21600984 DOI: 10.1016/j.nbd.2011.05.001] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2011] [Accepted: 05/03/2011] [Indexed: 10/18/2022] Open
Abstract
Multiple laboratories have recently demonstrated that long-term dopaminergic transplants form Lewy bodies in patients with Parkinson's disease. Debate has arisen as to whether these Lewy bodies form from the transfer of α synuclein from the host to the graft or whether they form from intrinsic responses of the graft from being placed into what was, or became, an inflammatory focus. To test whether the former hypothesis was possible, we grafted fetal rat ventral mesencephalon into the dopamine depleted striatum of rats that had previously received 6-hydroxydopamine lesions. One month after the transplant, rats received viral over expression of human α synuclein (AAV2/6-α synuclein) or green fluorescent protein (AAV2/6-GFP) into the striatum rostral to the grafts. Care was taken to make sure that the AAV injections were sufficiently distal to the graft so no cells would be directly transfected. All rats were sacrificed five weeks after the virus injections. Double label immunohistochemistry combined with confocal microscopy revealed that a small number of grafted tyrosine hydroxylase (TH) neurons (5.7% ± 1.5% (mean ± SEM) of grafted dopamine cells) expressed host derived α synuclein but none of the grafted cells expressed host-derived GFP. The α synuclein in a few of these cells was misfolded and failed to be digested with proteinase K. These data indicate that it is possible for host derived α synuclein to transfer to grafted neurons supporting the concept that this is one possible mechanism by which grafted dopamine neurons form Lewy bodies in Parkinson's disease patients.
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Affiliation(s)
- Jeffrey H Kordower
- Department of Neurological Sciences, Rush University Medical Center, Chicago, Illinois 60612, USA.
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24
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Spieles-Engemann AL, Behbehani MM, Collier TJ, Wohlgenant SL, Steece-Collier K, Paumier K, Daley BF, Gombash S, Madhavan L, Mandybur GT, Lipton JW, Terpstra BT, Sortwell CE. Stimulation of the rat subthalamic nucleus is neuroprotective following significant nigral dopamine neuron loss. Neurobiol Dis 2010; 39:105-15. [PMID: 20307668 DOI: 10.1016/j.nbd.2010.03.009] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Revised: 02/24/2010] [Accepted: 03/10/2010] [Indexed: 10/19/2022] Open
Abstract
Deep brain stimulation of the subthalamic nucleus (STN-DBS) is efficacious in treating the motor symptoms of Parkinson's disease (PD). However, the impact of STN-DBS on the progression of PD is unknown. Previous preclinical studies have demonstrated that STN-DBS can attenuate the degeneration of a relatively intact nigrostriatal system from dopamine (DA)-depleting neurotoxins. The present study examined whether STN-DBS can provide neuroprotection in the face of prior significant nigral DA neuron loss similar to PD patients at the time of diagnosis. STN-DBS between 2 and 4 weeks after intrastriatal 6-hydroxydopamine (6-OHDA) provided significant sparing of DA neurons in the SN of rats. This effect was not due to inadvertent lesioning of the STN and was dependent upon proper electrode placement. Since STN-DBS appears to have significant neuroprotective properties, initiation of STN-DBS earlier in the course of PD may provide added neuroprotective benefits in addition to its ability to provide symptomatic relief.
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Madhavan L, Daley B, Boudreau R, Cole-Strauss A, Collier T. P2.189 Neural stem cell mediated neuroprotection in a rat model of Parkinson's disease: role of endogenous precursors and graft-expressed molecules. Parkinsonism Relat Disord 2009. [DOI: 10.1016/s1353-8020(09)70540-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Madhavan L, Collier TJ. A synergistic approach for neural repair: cell transplantation and induction of endogenous precursor cell activity. Neuropharmacology 2009; 58:835-44. [PMID: 19853620 DOI: 10.1016/j.neuropharm.2009.10.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Revised: 10/12/2009] [Accepted: 10/15/2009] [Indexed: 12/11/2022]
Abstract
Stem cell research offers enormous potential for treating many diseases of the nervous system. At present, therapeutic strategies in stem cell research segregate into two approaches: cell transplantation or endogenous cell stimulation. Realistically, future cell therapies will most likely involve a combination of these two approaches, a theme of our current research. Here, we propose that there exists a 'synergy' between exogenous (transplanted) and endogenous stem cell actions that can be utilized to achieve therapeutic ends. Elucidating mechanisms underlying this exogenous-endogenous stem cell synergism may lead to the development of optimal cell therapies for neural disorders.
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Affiliation(s)
- Lalitha Madhavan
- Department of Neurology, University of Cincinnati, Cincinnati, OH 45267, USA.
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Madhavan L, Daley BF, Paumier KL, Collier TJ. Transplantation of subventricular zone neural precursors induces an endogenous precursor cell response in a rat model of Parkinson's disease. J Comp Neurol 2009; 515:102-15. [PMID: 19399899 DOI: 10.1002/cne.22033] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Realistically, future stem cell therapies for neurological conditions including Parkinson's disease (PD) will most probably entail combination treatment strategies, involving both the stimulation of endogenous cells and transplantation. Therefore, this study investigates these two modes of neural precursor cell (NPC) therapy in concert in order to determine their interrelationships in a rat PD model. Human placental alkaline phosphatase (hPAP)-labeled NPCs were transplanted unilaterally into host rats which were subsequently infused ipsilaterally with 6-hydroxydopamine (6-OHDA). The reaction of host NPCs to the transplantation and 6-OHDA was tracked by bromodeoxyuridine (BrdU) labeling. Two weeks after transplantation, in animals transplanted with NPCs we found evidence of elevated host subventricular zone NPC proliferation, neurogenesis, and migration to the graft site. In these animals, we also observed a significant preservation of striatal tyrosine hydroxylase (TH) expression and substantia nigra TH cell number. We have seen no evidence that neuroprotection is a product of dopamine neuron replacement by NPC-derived cells. Rather, the NPCs expressed glial cell line-derived neurotrophic factor (GDNF), sonic hedgehog (Shh), and stromal cell-derived factor 1 alpha (SDF1alpha), providing a molecular basis for the observed neuroprotection and endogenous NPC response to transplantation. In summary, our data suggests plausible synergy between exogenous and endogenous NPC actions, and that NPC implantation before the 6-OHDA insult can create a host microenvironment conducive to stimulation of endogenous NPCs and protection of mature nigral neurons.
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Affiliation(s)
- Lalitha Madhavan
- Department of Neurology, University of Cincinnati, Cincinnati, Ohio 45267, USA
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Madhavan L, Ourednik V, Ourednik J. Increased "vigilance" of antioxidant mechanisms in neural stem cells potentiates their capability to resist oxidative stress. Stem Cells 2006; 24:2110-9. [PMID: 16728559 DOI: 10.1634/stemcells.2006-0018] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Although the potential value of transplanted and endogenous neural stem cells (NSCs) for the treatment of the impaired central nervous system (CNS) has widely been accepted, almost nothing is known about their sensitivity to the hostile microenvironment in comparison to surrounding, more mature cell populations. Since many neuropathological insults are accompanied by oxidative stress, this report compared the alertness of antioxidant defense mechanisms and cell survival in NSCs and postmitotic neural cells (PNCs). Both primary and immortalized cells were analyzed. At steady state, NSCs distinguished themselves in their basal mitochondrial metabolism from PNCs by their lower reactive oxygen species (ROS) levels and higher expression of the key antioxidant enzymes uncoupling protein 2 (UCP2) and glutathione peroxidase (GPx). Following exposure to the mitochondrial toxin 3-nitropropionic acid, PNC cultures were marked by rapidly decreasing mitochondrial activity and increasing ROS content, both entailing complete cell loss. NSCs, in contrast, reacted by fast upregulation of UCP2, GPx, and superoxide dismutase 2 and successfully recovered from an initial deterioration. This recovery could be abolished by specific antioxidant inhibition. Similar differences between NSCs and PNCs regarding redox control efficiency were detected in both primary and immortalized cells. Our first in vivo data from the subventricular stem cell niche of the adult mouse forebrain corroborated the above observations and revealed strong baseline expression of UCP2 and GPx in the resident, proliferating NSCs. Thus, an increased "vigilance" of antioxidant mechanisms might represent an innate characteristic of NSCs, which not only defines their cell fate, but also helps them to encounter oxidative stress in diseased CNS.
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Affiliation(s)
- Lalitha Madhavan
- Department of Biomedical Sciences, College of Veterinary Medicine 2052, Iowa State University, Ames, 50011, USA
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Abstract
Here, we present our preliminary data showing that neural stem cells (NSCs) can prevent the degeneration of striatal neurons when transplanted into the CNS prior to intoxication with 3-nitropropionic acid (3-NP). In the adult CNS, the number of NSCs, a major source of neural cell populations and plasticity-modulating factors, is relatively low if compared to that of the developing brain. This, together with the adult growth-inhibitory environment, limits its regenerative capacity. Our recent observation has shown that grafted NSCs may rescue/protect neurons in the chronically impaired mesostriatal system. On the basis of this study and because we were also intrigued by our recent observations regarding the rescue/protective role of NSCs in vitro, we decided to test the hypothesis that grafted NSCs can also be deposited preventively in the CNS (and perhaps join the pool of endogenous NSCs of the intact host brain) for later buffering and maintenance of homeostasis when the host is exposed to oxidative stress.
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Affiliation(s)
- Lalitha Madhavan
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
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Mathew AT, Zacharias P, Ponnambathayil S, Kumar A, Madhavan L, Harris M, Ramakrishnan KG, Bhagyanathan PV. Massive gastrointestinal bleeding in a patient with AIDS. Natl Med J India 2005; 18:76-7. [PMID: 15981442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Cytomegalovirus enteritis can lead to gastrointestinal bleeding in patients with the acquired immune deficiency syndrome. The commonest site of involvement is the colon, followed by the stomach and terminal ileum. Most of these lesions can be diagnosed by colonoscopy or gastroscopy. We present our experience of a patient with cytomegalovirus infection involving only the proximal jejunum causing massive lower gastrointestinal bleeding. Conventional endoscopy and imaging had failed to locate the source of bleeding. Enteroscopy performed at the time of laparotomy showed an ulcerated lesion in the jejunum. Resection followed by histological examination of the resected area confirmed the diagnosis of cytomegalovirus infection. In addition to highly active antiretroviral therapy, ganciclovir was given for 14 days in a dose of 5 mg/kg twice a day and tapered over a period of 3 months. There has been no further episode of gastrointestinal bleeding over a follow up of 9 months.
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Affiliation(s)
- A T Mathew
- Malabar Institute of Medical Sciences, Mini Bypass Road, Govinthapuram, Calicut 673016, Kerala, India.
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Madhavan L, Freed WJ, Anantharam V, Kanthasamy AG. 5-hydroxytryptamine 1A receptor activation protects against N-methyl-D-aspartate-induced apoptotic cell death in striatal and mesencephalic cultures. J Pharmacol Exp Ther 2003; 304:913-23. [PMID: 12604665 DOI: 10.1124/jpet.102.044370] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Apoptosis and glutamate-mediated excitotoxicity may play a role in the pathogenesis of many neurodegenerative disorders, including Parkinson's disease (PD). In the present study, we investigated whether stimulation of the 5-hydroxytryptamine 1A (5-HT1A) receptor attenuates N-methyl-D-aspartate- (NMDA) and 1-methyl-4-phenylpyridinium (MPP(+))-induced apoptotic cell death in cell culture models. A brief exposure (20 min) of M213-2O striatal cells to NMDA and glutamate produced a delayed increase in caspase-3 activity and DNA fragmentation in a dose- and time-dependent manner. NMDA-induced caspase-3 activity and DNA fragmentation were almost completely blocked by the 5-HT1A agonists 8-hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT) and (R)-5-fluoro-8 hydroxy-2-(dipropylamino)-tetralin (R-UH-301). Additionally, the protective effects of 8-OH-DPAT and R-UH-301 on NMDA-induced caspase-3 activation and apoptosis were reversed by pretreatment with the 5-HT1A antagonists N-[2-[4-(2-methoxyphenyl)-1-piperazinyl] ethyl]-N-(2-pyridinyl) cyclohexane carboxamide (WAY 100635) and S-UH-301, respectively. Similarly, dose- and time-dependent increases in caspase-3 activity and DNA fragmentation were observed in rat primary mesencephalic neurons after a brief exposure to NMDA and glutamate. Caspase-3 activation and DNA fragmentation in primary mesencephalic neurons were almost completely inhibited by 8-OH-DPAT. This neuroprotective effect of 8-OH-DPAT was reversed by WAY 100635. Additionally, 8-OH-DPAT blocked tyrosine hydroxylase (TH)-positive cell death after NMDA exposure and also almost completely attenuated the NMDA-induced Ca(2+) influx in primary mesencephalic cultures. Furthermore, 8-OH-DPAT and R-UH-301 blocked apoptotic cell death in the primary mesencephalic neurons that were exposed to the Parkinsonian toxin MPP(+). Together, these results suggest that 5-HT1A receptor stimulation may be a promising pharmacological approach in the development of neuroprotective agents for PD.
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Affiliation(s)
- Lalitha Madhavan
- Parkinson's Disorder Research Laboratory, Department of Biomedical Sciences, Iowa State University, Ames, Iowa 50011-1250, USA
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