1
|
Bennett JP. Making a Case for Adult Orthodontics With Clear Aligner Therapy Provided by the General Dentist. Compend Contin Educ Dent 2022; 43:e1-e4. [PMID: 36227146] [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: 06/16/2023]
Abstract
In today's "digital" world, where consumers are able to complete most every task, from grocery shopping to banking, from the comfort of their bed, a strong emphasis is placed on convenience and simplicity. For dental patients who want healthy, functional, and esthetically pleasing teeth and smiles, clear aligners can be utilized in a relatively expedient manner to create more optimal conditions for their overall dental wellness. With existing digital workflows, clinicians are able to provide patients a healthy and esthetic dentition more easily than in the past. Cases presented in this report demonstrate the use of OraFit™ clear aligners to correct simple malocclusions and help provide the patients with the smiles they desired.
Collapse
Affiliation(s)
- James P Bennett
- Past Guest Faculty, Case Western Reserve University School of Dental Medicine, Cleveland, Ohio; Private Practice, Westlake, Ohio
| |
Collapse
|
2
|
Onyango IG, Bennett JP, Stokin GB. Mitochondrially-Targeted Therapeutic Strategies for Alzheimer's Disease. Curr Alzheimer Res 2021; 18:753-771. [PMID: 34879805 PMCID: PMC9178515 DOI: 10.2174/1567205018666211208125855] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 06/24/2021] [Accepted: 10/07/2021] [Indexed: 11/22/2022]
Abstract
Alzheimer’s disease (AD) is an irreversible, progressive neurodegenerative disease and the most common cause of dementia among older adults. There are no effective treatments available for the disease, and it is associated with great societal concern because of the substantial costs of providing care to its sufferers, whose numbers will increase as populations age. While multiple causes have been proposed to be significant contributors to the onset of sporadic AD, increased age is a unifying risk factor. In addition to amyloid-β (Aβ) and tau protein playing a key role in the initiation and progression of AD, impaired mitochondrial bioenergetics and dynamics are likely major etiological factors in AD pathogenesis and have many potential origins, including Aβ and tau. Mitochondrial dysfunction is evident in the central nervous system (CNS) and systemically early in the disease process. Addressing these multiple mitochondrial deficiencies is a major challenge of mitochondrial systems biology. We review evidence for mitochondrial impairments ranging from mitochondrial DNA (mtDNA) mutations to epigenetic modification of mtDNA, altered gene expression, impaired mitobiogenesis, oxidative stress, altered protein turnover and changed organelle dynamics (fission and fusion). We also discuss therapeutic approaches, including repurposed drugs, epigenetic modifiers, and lifestyle changes that target each level of deficiency which could potentially alter the course of this progressive, heterogeneous Disease while being cognizant that successful future therapeutics may require a combinatorial approach.
Collapse
Affiliation(s)
- Isaac G Onyango
- Centre for Translational Medicine International Clinical Research Centre, St. Anne's University Hospital CZ-65691,Brno. Czech Republic
| | - James P Bennett
- Neurodegeneration Therapeutics 3050A Berkmar Drive Charlottesville, VA22901. United States
| | - Gorazd B Stokin
- Translational Aging and Neuroscience Program, Mayo Clinic, 200 First St. SW, Rochester, MN55905. United States
| |
Collapse
|
3
|
Bennett JP, Onyango IG. Energy, Entropy and Quantum Tunneling of Protons and Electrons in Brain Mitochondria: Relation to Mitochondrial Impairment in Aging-Related Human Brain Diseases and Therapeutic Measures. Biomedicines 2021; 9:225. [PMID: 33671585 PMCID: PMC7927033 DOI: 10.3390/biomedicines9020225] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [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] [Received: 01/05/2021] [Revised: 02/18/2021] [Accepted: 02/18/2021] [Indexed: 11/16/2022] Open
Abstract
Adult human brains consume a disproportionate amount of energy substrates (2-3% of body weight; 20-25% of total glucose and oxygen). Adenosine triphosphate (ATP) is a universal energy currency in brains and is produced by oxidative phosphorylation (OXPHOS) using ATP synthase, a nano-rotor powered by the proton gradient generated from proton-coupled electron transfer (PCET) in the multi-complex electron transport chain (ETC). ETC catalysis rates are reduced in brains from humans with neurodegenerative diseases (NDDs). Declines of ETC function in NDDs may result from combinations of nitrative stress (NS)-oxidative stress (OS) damage; mitochondrial and/or nuclear genomic mutations of ETC/OXPHOS genes; epigenetic modifications of ETC/OXPHOS genes; or defects in importation or assembly of ETC/OXPHOS proteins or complexes, respectively; or alterations in mitochondrial dynamics (fusion, fission, mitophagy). Substantial free energy is gained by direct O2-mediated oxidation of NADH. Traditional ETC mechanisms require separation between O2 and electrons flowing from NADH/FADH2 through the ETC. Quantum tunneling of electrons and much larger protons may facilitate this separation. Neuronal death may be viewed as a local increase in entropy requiring constant energy input to avoid. The ATP requirement of the brain may partially be used for avoidance of local entropy increase. Mitochondrial therapeutics seeks to correct deficiencies in ETC and OXPHOS.
Collapse
Affiliation(s)
| | - Isaac G. Onyango
- International Clinical Research Center, St. Anne’s University Hospital, CZ-65691 Brno, Czech Republic;
| |
Collapse
|
4
|
Abstract
Neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis are a heterogeneous group of debilitating disorders with multifactorial etiologies and pathogeneses that manifest distinct molecular mechanisms and clinical manifestations with abnormal protein dynamics and impaired bioenergetics. Mitochondrial dysfunction is emerging as an important feature in the etiopathogenesis of these age-related neurodegenerative diseases. The prevalence and incidence of these diseases is on the rise with the increasing global population and average lifespan. Although many therapeutic approaches have been tested, there are currently no effective treatment routes for the prevention or cure of these diseases. We present the current status of our knowledge and understanding of the involvement of mitochondrial dysfunction in these diseases and highlight recent advances in novel therapeutic strategies targeting neuronal bioenergetics as potential approach for treating these diseases.
Collapse
Affiliation(s)
- Isaac G Onyango
- Center for Translational Medicine, International Clinical Research Centre (ICRC), St. Anne's University Hospital, Brno, Czech Republic
| | - James P Bennett
- Neurodegeneration Therapeutics, 3050A Berkmar Drive, Charlottesville, VA, USA
| | - Gorazd B Stokin
- Center for Translational Medicine, International Clinical Research Centre (ICRC), St. Anne's University Hospital, Brno, Czech Republic
| |
Collapse
|
5
|
Bennett JP, Keeney PM. Alzheimer's and Parkinson's brain tissues have reduced expression of genes for mtDNA OXPHOS Proteins, mitobiogenesis regulator PGC-1α protein and mtRNA stabilizing protein LRPPRC (LRP130). Mitochondrion 2020; 53:154-157. [PMID: 32497722 DOI: 10.1016/j.mito.2020.05.012] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 05/18/2020] [Accepted: 05/26/2020] [Indexed: 12/31/2022]
Abstract
We used RNA sequencing (RNA-seq) to quantitate gene expression in total RNA extracts of vulnerable brain tissues from Alzheimer's disease (AD, frontal cortical ribbon) and Parkinson's disease (PD, ventral midbrain) subjects and phenotypically negative control subjects. Paired-end sequencing files were processed with HISAT2 aligner/Cufflinks quantitation against the hg38 human genome. We observed a significant decrease in gene expression of all mtDNA OXPHOS genes in AD and PD tissues. Gene expression of the master mitochondrial biogenesis regulator PGC-1α (PPARGC1A) was significantly reduced in AD; expression of genes for mitochondrial transcription factors A (TFAM) and B1/B2 (TFB1M/TFB2M) were not significantly changed in AD and PD tissues. 2-way ANOVAs showed significant reduction in AD brain Complex I subunits' expressions and nearly significant reductions in PD brain. We found a significant reduction in both AD and PD brain samples of expression of genes for leucine-rich pentatricopeptide repeat containing (LRPPRC, a.k.a. LRP130), a known mtRNA-stabilizing protein. Our findings suggest that AD and PD brain tissues have a reduction in mitochondrial ATP production derived from a reduction of mitobiogenesis and mtRNA stability. If true, increased brain expression of PGC-1α and/or LRPPRC may improve bioenergetics of AD and PD and alter the course of neurodegeneration in both conditions. (201 words).
Collapse
Affiliation(s)
- James P Bennett
- Neurodegeneration Therapeutics, Inc., Charlottesville, VA 22901, United States.
| | - Paula M Keeney
- Neurodegeneration Therapeutics, Inc., Charlottesville, VA 22901, United States
| |
Collapse
|
6
|
Bennett JP, Keeney PM, Brohawn DG. RNA Sequencing Reveals Small and Variable Contributions of Infectious Agents to Transcriptomes of Postmortem Nervous Tissues From Amyotrophic Lateral Sclerosis, Alzheimer's Disease and Parkinson's Disease Subjects, and Increased Expression of Genes From Disease-Activated Microglia. Front Neurosci 2019; 13:235. [PMID: 30983949 PMCID: PMC6447612 DOI: 10.3389/fnins.2019.00235] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [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] [Accepted: 02/27/2019] [Indexed: 12/11/2022] Open
Abstract
Nervous tissues from both humans with neurodegenerative diseases (NDD) and animals with genetic models of human NDD, such as rare monogenic causes of Amyotrophic Lateral Sclerosis (ALS), Alzheimer's disease (AD), and Parkinson's disease (PD), show activated microglia, suggesting a potential causal role for inflammation in pathogenesis of NDD. We performed paired-end (PE) RNA sequencing (RNA seq) of total RNA's extracted from frozen sections of cervical spinal cords from ALS and CTL subjects, frontal cortical gray matter ribbons of AD and CTL subjects, and ventral midbrains of PD and CTL subjects. Trimmed PE reads were aligned against the hg38 human transcriptome using Tophat2/Bowtie2 (ALS) or HISAT2 (AD and PD) and quantitated with Cufflinks. PE reads were also aligned using Bowtie2 against genomes from representative species of Toxoplasma gondii and Trichinella sp. T6 (parasitic infectious agents), Babesia microti and Borrelia burgdorferi (tick-vector borne agents), and Treponema denticola and Porphyromonas gingivalis, agents causing chronic gingivitis. Primary aligned reads of each agent in each tissue sample were quantitated with SAMtools. We found small percentages (<0.1%) of transcriptomes aligned with B. microti, B. burgdorferi, T. denticola, and P. gingivalis genomes and larger percentages aligned with T. gondii (0.1-0.2%) and Trichinella sp. T6 (1.0-1.1%) genomes. In AD specimens, but in no others, primary aligned transcriptome percentages, although small, approached significance for being greater in AD compared to CTL samples for B. burgdorferi (p = 0.067) and P. gingivalis (p = 0.068). Genes' expressions in postmortem tissues of AD and ALS but not PD revealed significant changes among disease-associated microglial (DAM) genes. Infectious agents' transcripts can be detected in RNA seq reads of both NDD and CTL tissues and vary from agent to agent. Expressions of Stage 1 and Stage 2 DAM genes significantly changed, suggesting the presence of Stages 1 and 2 DAM in our NDD tissue samples.
Collapse
Affiliation(s)
- James P Bennett
- Neurodegeneration Therapeutics, Inc., Charlottesville, VA, United States.,Parkinson's and Movement Disorders Center, Virginia Commonwealth University, Richmond, VA, United States
| | - Paula M Keeney
- Neurodegeneration Therapeutics, Inc., Charlottesville, VA, United States.,Parkinson's and Movement Disorders Center, Virginia Commonwealth University, Richmond, VA, United States
| | - David G Brohawn
- Parkinson's and Movement Disorders Center, Virginia Commonwealth University, Richmond, VA, United States.,Department of Medical Genetics, Virginia Commonwealth University, Richmond, VA, United States
| |
Collapse
|
7
|
Bennett JP. Medical hypothesis: Neurodegenerative diseases arise from oxidative damage to electron tunneling proteins in mitochondria. Med Hypotheses 2019; 127:1-4. [PMID: 31088629 DOI: 10.1016/j.mehy.2019.03.034] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Revised: 03/26/2019] [Accepted: 03/27/2019] [Indexed: 12/15/2022]
Abstract
Mitochondria likely arose from serial endosymbiosis by early eukaryotic cells and control electron flow to molecular oxygen to facilitate energy transformation. Mitochondria translate between the quantum and macroscopic worlds and utilize quantum tunneling of electrons to reduce activation energy barriers to electron flow. Electron tunneling has been extensively characterized in Complex I of the electron transport chain. Age-related increases in oxidative damage to these electron tunneling systems may account for decreased energy storage found in aged and neurodegenerative disease tissues, such as those from sufferers of amyotrophic lateral sclerosis (ALS), Alzheimer's disease (AD) and Parkinson's disease (PD). This hypothesis is testable. If correct, this hypothesis supports pre-symptomatic, mitochondrially-directed oxygen free radical scavenging therapies.
Collapse
Affiliation(s)
- James P Bennett
- Neurodegeneration Therapeutics, Inc., 3050A Berkmar Drive, Charlottesville, VA 22901-3450, United States.
| |
Collapse
|
8
|
Bennett JP, Keeney PM. RNA-Sequencing Reveals Similarities and Differences in Gene Expression in Vulnerable Brain Tissues of Alzheimer's and Parkinson's Diseases. J Alzheimers Dis Rep 2018; 2:129-137. [PMID: 30480256 PMCID: PMC6159702 DOI: 10.3233/adr-180072] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [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] [Accepted: 06/11/2018] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Neuropathological changes of Alzheimer's disease (AD) and Parkinson's disease (PD) can coexist in the same sample, suggesting possible common degenerative mechanisms. OBJECTIVE The objective of this study was to use RNA-sequencing to compare gene expression in AD and PD vulnerable brain regions and search for co-expressed genes. METHODS Total RNA was isolated from AD/CTL frontal cortex and PD/CTL ventral midbrain. Sequencing libraries were prepared, multiplex paired-end RNA sequencing was carried out, and bioinformatics analyses of gene expression used both publicly available (tophat2/bowtie2/Cufflinks) and commercial (Qlucore Omics Explorer) algorithms. RESULTS Both AD (frontal cortex, n = 10) and PD (ventral midbrain, n = 14) samples showed extensive heterogeneity of gene expression. Hierarchical clustering of heatmaps revealed two gene populations (AD, 376 genes; PD, 351 genes) that separated AD or PD from control samples at false-discovery rates (q) of <5% and fold changes of at least 1.3 (AD) or 1.5 (PD). 10,124 genes were co-expressed in our AD and PD samples. A very small group of these genes (n = 23) showed both low variances (<150; variance = standard deviation squared) and reduced expressions (>1.5-fold under-expression) in both AD and PD. Ingenuity Pathways Analyses (IPA, Qiagen) revealed loss of NAD biosynthesis and salvage as the major canonical pathway significantly altered in both AD and PD. CONCLUSIONS AD and PD in vulnerable brain regions appear to arise from and result in independent molecular genetic abnormalities, but we identified several under-expressed genes with potential to treat both diseases. NAD supplementation shows particular promise.
Collapse
Affiliation(s)
| | - Paula M. Keeney
- Neurodegeneration Therapeutics, Inc., Charlottesville, VA, USA
| |
Collapse
|
9
|
Abstract
A short-term clinical study on the effect of purified angiogenic and growth factors from human term placenta in the treatment of chronic varicose ulcers was carried out in 18 patients. Patients were randomly allocated to receive a maximum of two dressings containing or not containing these factors. The amount of granulation and epithelial tissue was clinically estimated 48 hours after each application. Patients treated with placental angiogenic and growth factors showed increased granulation and epithelial tissue. These results indicate that placental factors may be used for acceleration of wound healing.
Collapse
Affiliation(s)
- H Burgos
- Blond McIndoe Centre for Medical Research, Queen Victoria Hospital, East Grinstead, Sussex
| | | | | |
Collapse
|
10
|
|
11
|
Leonard CE, Fryman SP, Turner MP, Bennett JP, Carter DL, Sing AP. Abstract P4-15-08: Association of OncotypeDX® DCIS ScoreTM results with local recurrence in patients with DCIS treated on accelerated partial breast radiotherapy (APBI) protocols. Cancer Res 2018. [DOI: 10.1158/1538-7445.sabcs17-p4-15-08] [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: 11/16/2022]
Abstract
Abstract
Background: Ductal carcinoma in situ (DCIS) is a proliferation of malignant epithelial cells of the ducts and terminal lobular units of the breast that do not invade the basement membrane. The incidence of DCIS has increased markedly since the early 1980s, chiefly due to screening mammography. Whole breast radiotherapy has largely been used to treat breast DCIS after lumpectomy. More recently, APBI has increasingly been utilized for breast DCIS. Currently updated American Society of Radiation Oncology (ASTRO) APBI guidelines have included "low risk" DCIS (as defined by RTOG 9804 criteria). The following results further explore clinico-pathologic factors, in addition to the DCIS Score, in order to better define an appropriate DCIS population for APBI.
Methods: An exploratory analysis aimed to retrospectively measure the association between clinico-pathologic factors and the DCIS Score result, an optimized 12-gene expression algorithm, and risk of any local failure (in situ or IBC recurrence) in a cohort of women treated with local excision and APBI on prospective phase II (NCT01185145) and phase III (NCT01185132) clinical trials. Multifocal tumors were described only by local pathology and not determined or defined centrally. The DCIS Score assay was performed by quantitative RT-PCR on formalin-fixed paraffin-embedded DCIS tumor specimens by Genomic Health (Redwood City, CA). Descriptive statistics of the cohort and assay results overall and by clinical trial were derived. Univariable Cox proportional hazards regression was used to determine whether there was an association between local failure and categorized DCIS Score group (≥39 vs <39) or other clinico-pathologic factors on the pooled cohort of clinical trial patients.
Results: This analysis included 104 evaluable patients (N=18 from NCT01185145 and N=86 from NCT01185132). The median age was 60 (range: 41-80), 79% of patients were postmenopausal, and the median span of DCIS was 6 mm (range 2-25 mm). Over two-thirds of the cohort presented with necrosis (71%). The distribution of DCIS Score results ranged from 0 to 82, with 69% of patients having a DCIS Score result <39. The median follow-up time was longer at 8.2 years in NCT01185145 versus 3.0 years in NCT01185132. There was a total of 6 local recurrences. DCIS Score result was significantly associated with local recurrence in univariable modeling (hazard ratio=10.3 for ≥39 vs <39; p=0.0104). None of the other clinico-pathologic characteristics resulted in any significant correlation with locoregional recurrence. All results were highly variable due to the small number of events.
Conclusion: The DCIS Score assay demonstrated risk stratification in this cohort of patients treated with local excision and APBI pooled from two clinical trials. These results are consistent with those recently published by Rakovitch et al (J Natl Cancer Inst 2017). The cohort in this study was dominated by those in the phase III trial. Due to the small number of local recurrence events and limited follow-up time in the phase III trial, caution should be taken when interpreting the results. Further investigations are needed to confirm findings.
Citation Format: Leonard CE, Fryman SP, Turner MP, Bennett JP, Carter DL, Sing AP. Association of OncotypeDX® DCIS ScoreTM results with local recurrence in patients with DCIS treated on accelerated partial breast radiotherapy (APBI) protocols [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-15-08.
Collapse
Affiliation(s)
- CE Leonard
- Rocky Mountain Cancer Centers, Littleton, CO; Rocky Mountain Cancer Centers, Aurora, CO; Genomic Health, Inc., Redwood City, CA
| | - SP Fryman
- Rocky Mountain Cancer Centers, Littleton, CO; Rocky Mountain Cancer Centers, Aurora, CO; Genomic Health, Inc., Redwood City, CA
| | - MP Turner
- Rocky Mountain Cancer Centers, Littleton, CO; Rocky Mountain Cancer Centers, Aurora, CO; Genomic Health, Inc., Redwood City, CA
| | - JP Bennett
- Rocky Mountain Cancer Centers, Littleton, CO; Rocky Mountain Cancer Centers, Aurora, CO; Genomic Health, Inc., Redwood City, CA
| | - DL Carter
- Rocky Mountain Cancer Centers, Littleton, CO; Rocky Mountain Cancer Centers, Aurora, CO; Genomic Health, Inc., Redwood City, CA
| | - AP Sing
- Rocky Mountain Cancer Centers, Littleton, CO; Rocky Mountain Cancer Centers, Aurora, CO; Genomic Health, Inc., Redwood City, CA
| |
Collapse
|
12
|
C Ladd A, G Brohawn D, P Bennett J. Laser-captured spinal cord motorneurons from ALS subjects show increased gene expression in vacuolar ATPase networks. ACTA ACUST UNITED AC 2017. [DOI: 10.15761/jsin.1000182] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
13
|
Bennett JP, O'Brien LC, Brohawn DG. Pharmacological properties of microneurotrophin drugs developed for treatment of amyotrophic lateral sclerosis. Biochem Pharmacol 2016; 117:68-77. [PMID: 27498123 DOI: 10.1016/j.bcp.2016.08.001] [Citation(s) in RCA: 16] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 08/01/2016] [Indexed: 12/13/2022]
Abstract
Microneurotrophins (MNT's) are small molecule derivatives of dehydroepiandrosterone (DHEA) and do not have significant interactions with sex steroid receptors. MNT's retain high-affinity binding to protein tyrosine kinase (Trk) receptors and can mimic many pleiotropic actions of neurotrophin (NT) proteins on neurons. MNT's offer therapeutic potential for diseases such as amyotrophic lateral sclerosis (ALS) where motor neurons (MN) degenerate. MNT's cross artificial membranes mimicking the blood-brain barrier, are not major substrates for ABC (ATP-binding cassette) transporters and are metabolized rapidly by mouse but more slowly by human hepatocytes. A lead MNT (BNN27) and its mono-oxidation metabolites enter mouse brain rapidly. RNA-sequencing measured gene expression profiles of human H9eSC-(embryonic stem cell)-derived or CTL (control) subject iPSC-(induced pluripotential stem cell)-derived MN's exposed to NT proteins or MNT molecules. Expression ratios (relative to DMSO (dimethylsulfoxide) vehicle) were calculated, and the resulting top 500 gene lists were analyzed for Gene Ontology (GO) grouping using DAVID (Database for Annotation, Visualization and Integrated Discovery). The MNT's BNN20, BNN23, and BNN27 showed overlap of GO terms with NGF (nerve growth factor) and BDNF (brain-derived neurotrophic factor) in the H9eSC-derived MN's. In the iPSC-derived MN's two (BNN20, BNN27) showed overlap of GO terms with NGF or BDNF. Each NT protein had GO terms that did not overlap with any MNT in the MN cell lines.
Collapse
Affiliation(s)
- James P Bennett
- Parkinson's Disease Research Center, Virginia Commonwealth University, Richmond, VA, United States; Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, VA, United States; Department of Neurology, Virginia Commonwealth University, Richmond, VA, United States; Neurodegeneration Therapeutics, Inc., Charlottesville, VA, United States.
| | - Laura C O'Brien
- Parkinson's Disease Research Center, Virginia Commonwealth University, Richmond, VA, United States; Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, VA, United States
| | - David G Brohawn
- Parkinson's Disease Research Center, Virginia Commonwealth University, Richmond, VA, United States; Department of Human Genetics, Virginia Commonwealth University, Richmond, VA, United States
| |
Collapse
|
14
|
Bennett JP, Boulicault D. A spotlight on microneurotrophins: the future of amyotrophic lateral sclerosis treatment? Neurodegener Dis Manag 2016; 5:181-5. [PMID: 26107316 DOI: 10.2217/nmt.15.13] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
15
|
Rice AC, Ladd AC, Bennett JP. Postmortem Alzheimer's Disease Hippocampi Show Oxidative Phosphorylation Gene Expression Opposite that of Isolated Pyramidal Neurons. J Alzheimers Dis 2016; 45:1051-9. [PMID: 25720395 DOI: 10.3233/jad-142937] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [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: 11/15/2022]
Abstract
Causes of initiation and progression of sporadic Alzheimer's disease (sAD) are likely multiple and include impairment of mitochondrial bioenergetics. We analyzed RNA expression levels of multiple mitochondrial oxidative phosphorylation (OXPHOS) and biogenesis (mitobiogenesis) genes in unfixed hippocampal (WH) frozen sections (10 sAD; 9 CTL) and laser-captured hippocampal pyramidal neurons (PyNs, ~1000 neurons from each case) from 8 sAD and 7 CTL cases. Nuclear-encoded OXPHOS genes in WH were significantly increased in sAD, whereas in isolated sAD PyNs, these same genes were significantly decreased. Mitochondrial DNA-encoded genes were increased in sAD PyNs but showed a non-significant downward trend in sAD WH. Relationships among WH and PyN gene expression levels in sAD distributed in a different population compared to CTL. Principal component analysis (PCA) revealed clustering of CTL but widespread heterogeneity of sAD samples. In sAD, mitochondrial bioenergetics at the gene expression level are depressed in vulnerable PyNs. PCA revealed that CTL samples clustered together, whereas sAD samples varied widely. From the perspective of OXPHOS bioenergetics, sAD is a heterogeneous syndrome and not likely due to a single abnormality. Increased stimulation of nuclear-encoded OXPHOS gene expression in PyNs is a rational therapeutic approach for most but not all cases of sAD.
Collapse
Affiliation(s)
- Ann C Rice
- Parkinson's and Movement Disorders Center, Virginia Commonwealth University, Richmond, VA, USA Department of Neurology, Virginia Commonwealth University, Richmond, VA, USA
| | - Amy C Ladd
- Parkinson's and Movement Disorders Center, Virginia Commonwealth University, Richmond, VA, USA
| | - James P Bennett
- Parkinson's and Movement Disorders Center, Virginia Commonwealth University, Richmond, VA, USA Department of Neurology, Virginia Commonwealth University, Richmond, VA, USA Department of Psychiatry, Virginia Commonwealth University, Richmond, VA, USA Department of Physiology & Biophysics, Virginia Commonwealth University, Richmond, VA, USA
| |
Collapse
|
16
|
|
17
|
Bennett JP, Barcelo D. Changes Coming to Science of the Total Environment. Sci Total Environ 2015; 533:vi-vii. [PMID: 26319736 DOI: 10.1016/j.scitotenv.2015.07.128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
|
18
|
Lochmann TL, Thomas RR, Bennett JP, Taylor SM. Epigenetic Modifications of the PGC-1α Promoter during Exercise Induced Expression in Mice. PLoS One 2015; 10:e0129647. [PMID: 26053857 PMCID: PMC4460005 DOI: 10.1371/journal.pone.0129647] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [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: 12/01/2014] [Accepted: 05/12/2015] [Indexed: 11/18/2022] Open
Abstract
The transcriptional coactivator, PGC-1α, is known for its role in mitochondrial biogenesis. Although originally thought to exist as a single protein isoform, recent studies have identified additional promoters which produce multiple mRNA transcripts. One of these promoters (promoter B), approximately 13.7kb upstream of the canonical PGC-1α promoter (promoter A), yields alternative transcripts present at levels much lower than the canonical PGC-1α mRNA transcript. In skeletal muscle, exercise resulted in a substantial, rapid increase of mRNA of these alternative PGC-1α transcripts. Although the β2-adrenergic receptor was identified as a signaling pathway that activates transcription from PGC-1α promoter B, it is not yet known what molecular changes occur to facilitate PGC-1α promoter B activation following exercise. We sought to determine whether epigenetic modifications were involved in this exercise response in mouse skeletal muscle. We found that DNA hydroxymethylation correlated to increased basal mRNA levels from PGC-1α promoter A, but that DNA methylation appeared to play no role in the exercise-induced activation of PGC-1α promoter B. The level of the activating histone mark H3K4me3 increased with exercise 2–4 fold across PGC-1α promoter B, but remained unaltered past the canonical PGC-1α transcriptional start site. Together, these data show that epigenetic modifications partially explain exercise-induced changes in the skeletal muscle mRNA levels of PGC-1α isoforms.
Collapse
Affiliation(s)
- Timothy L. Lochmann
- Massey Cancer Center, Virginia Commonwealth University, Richmond, Virginia, United States of America
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Ravindar R. Thomas
- Parkinson’s Center, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - James P. Bennett
- Parkinson’s Center, Virginia Commonwealth University, Richmond, Virginia, United States of America
- Department of Neurology, Virginia Commonwealth University, Richmond, Virginia, United States of America
- Department of Psychiatry, Virginia Commonwealth University, Richmond, Virginia, United States of America
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Shirley M. Taylor
- Massey Cancer Center, Virginia Commonwealth University, Richmond, Virginia, United States of America
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, Virginia, United States of America
- * E-mail:
| |
Collapse
|
19
|
O'Brien LC, Keeney PM, Bennett JP. Differentiation of Human Neural Stem Cells into Motor Neurons Stimulates Mitochondrial Biogenesis and Decreases Glycolytic Flux. Stem Cells Dev 2015; 24:1984-94. [PMID: 25892363 DOI: 10.1089/scd.2015.0076] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Differentiation of human pluripotent stem cells (hPSCs) in vitro offers a way to study cell types that are not accessible in living patients. Previous research suggests that hPSCs generate ATP through anaerobic glycolysis, in contrast to mitochondrial oxidative phosphorylation (OXPHOS) in somatic cells; however, specialized cell types have not been assessed. To test if mitobiogenesis is increased during motor neuron differentiation, we differentiated human embryonic stem cell (hESC)- and induced pluripotent stem cell-derived human neural stem cells (hNSCs) into motor neurons. After 21 days of motor neuron differentiation, cells increased mRNA and protein levels of genes expressed by postmitotic spinal motor neurons. Electrophysiological analysis revealed voltage-gated currents characteristic of excitable cells and action potential formation. Quantitative PCR revealed an increase in peroxisome proliferator-activated receptor gamma coactivator 1-α (PGC-1α), an upstream regulator of transcription factors involved in mitobiogenesis, and several of its downstream targets in hESC-derived cultures. This correlated with an increase in protein expression of respiratory subunits, but no increase in protein reflecting mitochondrial mass in either cell type. Respiration analysis revealed a decrease in glycolytic flux in both cell types on day 21 (D21), suggesting a switch from glycolysis to OXPHOS. Collectively, our findings suggest that mitochondrial biogenesis, but not mitochondrial mass, is increased during differentiation of hNSCs into motor neurons. These findings help us to understand human motor neuron mitobiogenesis, a process impaired in amyotrophic lateral sclerosis, a neurodegenerative disease characterized by death of motor neurons in the brain and spinal cord.
Collapse
Affiliation(s)
- Laura C O'Brien
- 1 Department of Physiology and Biophysics, Virginia Commonwealth University , Richmond, Virginia
| | - Paula M Keeney
- 2 VCU Parkinson's and Movement Disorders Center, Virginia Commonwealth University , Richmond, Virginia
| | - James P Bennett
- 1 Department of Physiology and Biophysics, Virginia Commonwealth University , Richmond, Virginia.,2 VCU Parkinson's and Movement Disorders Center, Virginia Commonwealth University , Richmond, Virginia.,3 Department of Neurology, Virginia Commonwealth University , Richmond, Virginia.,4 Department of Psychiatry, Virginia Commonwealth University , Richmond, Virginia
| |
Collapse
|
20
|
Ladd AC, Keeney PM, Govind MM, Bennett JP. Mitochondrial oxidative phosphorylation transcriptome alterations in human amyotrophic lateral sclerosis spinal cord and blood. Neuromolecular Med 2014; 16:714-26. [PMID: 25081190 DOI: 10.1007/s12017-014-8321-y] [Citation(s) in RCA: 28] [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: 04/22/2014] [Accepted: 07/18/2014] [Indexed: 12/12/2022]
Abstract
Origins of onset and progression of motor neurodegeneration in amyotrophic lateral sclerosis (ALS) are not clearly known, but may include impairment of mitochondrial bioenergetics. We used quantitative PCR approaches to analyze the mitochondrial oxidative phosphorylation (OXPHOS) transcriptomes of spinal cord tissue and peripheral blood mononuclear cells (PBMC) from persons with sporadic ALS compared with those without neurological disease. Expression measurements of 88 different nuclear (n) and mitochondrial (mt) DNA-encoded OXPHOS genes showed mtDNA-encoded respiratory gene expression was significantly decreased in ALS spinal cord by 78-84% (ANOVA p < 0.002). We observed the same phenomenon in freshly isolated PBMC from ALS patients (reduced 24-35%, ANOVA p < 0.001) and reproduced it in a human neural stem cell model treated with 2',3'-dideoxycytidine (ddC) (reduced 52-78%, ANOVA p < 0.001). nDNA-encoded OXPHOS genes showed heterogeneously and mostly decreased expression in ALS spinal cord tissue. In contrast, ALS PBMC and ddC-treated stem cells showed no significant change in expression of nDNA OXPHOS genes compared with controls. Genes related to mitochondrial biogenesis (PGC-1α, TFAM, ERRα, NRF1, NRF2 and POLG) were queried with inconclusive results. Here, we demonstrate there is a systemic decrease in mtDNA gene expression in ALS central and peripheral tissues that support pursuit of bioenergetic-enhancing therapies. We also identified a combined nDNA and mtDNA gene set (n = 26), downregulated in spinal cord tissue that may be useful as a biomarker in the development of cell-based ALS models.
Collapse
Affiliation(s)
- Amy C Ladd
- Parkinson's and Movement Disorders Center, Virginia Commonwealth University, P.O. Box 980312, Richmond, VA, 23298, USA,
| | | | | | | |
Collapse
|
21
|
Abstract
Parkinson's disease (PD) can include a progressive frontal lobe α-synucleinopathy with disability from cognitive decline and cortico-limbic dysregulation that may arise from bioenergetic impairments. We examined in PD frontal cortex regulation of mitochondrial biogenesis (mitobiogenesis) and its effects on Complex-I. We quantified expression of 33 nuclear genome (nDNA)-encoded and 7 mitochondrial genome (mtDNA)-encoded Complex-I genes, 6 Complex-I assembly factors and multiple mitobiogenesis genes. We related these findings to levels of Complex-I proteins and NADH-driven electron flow in mitochondria from these same specimens reported in earlier studies. We found widespread, decreased expression of nDNA Complex-I genes that correlated in some cases with mitochondrial Complex-I protein levels, and of ACAD9, a Complex-I assembly factor. mtDNA-transcribed Complex-I genes showed ~ constant expression within each PD sample but variable expression across PD samples that correlated with NRF1. Relationships among PGC-1α and its downstream targets NRF1 and TFAM were very similar in PD and CTL and were related to mitochondrial NADH-driven electron flow. MicroRNA arrays revealed multiple miRNA's regulated >2-fold predicted to interact with PGC-1α or its upstream regulators. Exposure of cultured human neurons to NO, rotenone and TNF-alpha partially reproduced mitobiogenesis down-regulation. In PD frontal cortex mitobiogenesis signaling relationships are maintained but down-regulated, correlate with impaired mitochondrial NADH-driven electron flow and may arise from combinations of nitrosative/oxidative stresses, inflammatory cytokines, altered levels of mitobiogenesis gene-interacting microRNA's, or other unknown mechanisms. Stimulation of mitobiogenesis in PD may inhibit rostral disease progression and appearance of secondary symptoms referable to frontal cortex.
Collapse
Affiliation(s)
- Ravindar R Thomas
- Parkinson's Disease Research Center, Virginia Commonwealth University, Richmond, VA 23298, USA
| | | | | |
Collapse
|
22
|
Thomas RR, Khan SM, Smigrodzki RM, Onyango IG, Dennis J, Khan OM, Portelli FR, Bennett JP. RhTFAM treatment stimulates mitochondrial oxidative metabolism and improves memory in aged mice. Aging (Albany NY) 2013; 4:620-35. [PMID: 23075607 PMCID: PMC3492226 DOI: 10.18632/aging.100488] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Mitochondrial function declines with age in postmitotic tissues such as brain, heart and skeletal muscle. Despite weekly exercise, aged mice showed substantial losses of mtDNA gene copy numbers and reductions in mtDNA gene transcription and mitobiogenesis signaling in brain and heart. We treated these mice with weekly intravenous injections of recombinant human mitochondrial transcription factor A (rhTFAM). RhTFAM treatment for one month increased mitochondrial respiration in brain, heart and muscle, POLMRT expression and mtDNA gene transcription in brain, and PGC-1 alpha mitobiogenesis signaling in heart. RhTFAM treatment reduced oxidative stress damage to brain proteins, improved memory in Morris water maze performance and increased brain protein levels of BDNF and synapsin. Microarray analysis showed co-expression of multiple Gene Ontology families in rhTFAM-treated aged brains compared to young brains. RhTFAM treatment reverses age-related memory impairments associated with loss of mitochondrial energy production in brain, increases levels of memory-related brain proteins and improves mitochondrial respiration in brain and peripheral tissues.
Collapse
Affiliation(s)
- Ravindar R Thomas
- Parkinson's Disease Center, Virginia Commonwealth University, Richmond, VA 23298, USA
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Cronin-Furman EN, Borland MK, Bergquist KE, Bennett JP, Trimmer PA. Mitochondrial quality, dynamics and functional capacity in Parkinson's disease cybrid cell lines selected for Lewy body expression. Mol Neurodegener 2013; 8:6. [PMID: 23351342 PMCID: PMC3577453 DOI: 10.1186/1750-1326-8-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [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: 08/31/2012] [Accepted: 01/21/2013] [Indexed: 12/13/2022] Open
Abstract
Background Lewy bodies (LB) are a neuropathological hallmark of Parkinson’s disease (PD) and other synucleinopathies. The role their formation plays in disease pathogenesis is not well understood, in part because studies of LB have been limited to examination of post-mortem tissue. LB formation may be detrimental to neuronal survival or merely an adaptive response to other ongoing pathological processes. In a human cytoplasmic hybrid (cybrid) neural cell model that expresses mitochondrial DNA from PD patients, we observed spontaneous formation of intracellular protein aggregates (“cybrid LB” or CLB) that replicate morphological and biochemical properties of native, cortical LB. We studied mitochondrial morphology, bioenergetics and biogenesis signaling by creating stable sub-clones of three PD cybrid cell lines derived from cells expressing CLB. Results Cloning based on CLB expression had a differential effect on mitochondrial morphology, movement and oxygen utilization in each of three sub-cloned lines, but no long-term change in CLB expression. In one line (PD63CLB), mitochondrial function declined compared to the original PD cybrid line (PD63Orig) due to low levels of mtDNA in nucleoids. In another cell line (PD61Orig), the reverse was true, and cellular and mitochondrial function improved after sub-cloning for CLB expression (PD61CLB). In the third cell line (PD67Orig), there was no change in function after selection for CLB expression (PD67CLB). Conclusions Expression of mitochondrial DNA derived from PD patients in cybrid cell lines induced the spontaneous formation of CLB. The creation of three sub-cloned cybrid lines from cells expressing CLB resulted in differential phenotypic changes in mitochondrial and cellular function. These changes were driven by the expression of patient derived mitochondrial DNA in nucleoids, rather than by the presence of CLB. Our studies suggest that mitochondrial DNA plays an important role in cellular and mitochondrial dysfunction in PD. Additional studies will be needed to assess the direct effect of CLB expression on cellular and mitochondrial function.
Collapse
Affiliation(s)
- Emily N Cronin-Furman
- Parkinson's and Movement Disorders Center, Virginia Commonwealth University, Richmond, VA 23298, USA
| | | | | | | | | |
Collapse
|
24
|
Abstract
Impaired brain energy production, reflected by reduced cortical glucose metabolism seen on 2-FDG PET scans, has emerged as a robust biomarker of mild cognitive impairment (MCI). Progression from MCI to Alzheimer's disease (AD) shows further decline of cortical 2-FDG uptake, implying worsening bioenergetics. We characterized respiration, respiratory protein levels, and gene expressions for mitochondrial DNA (mtDNA), mitochondrial biogenesis, and antioxidative signaling in preparations from postmortem AD and control frontal cortex. Mitochondrial respiration was maintained in frozen brain mitochondria and reduced by approximately two-thirds in AD due to loss of mitochondrial mass. Levels of most respiratory proteins were preserved, but expressions of gene families for mtDNA, mitobiogenesis, and mitochondrial/cytosolic antioxidant enzymes were reduced in AD cortex. None of these changes in AD were related to elevated levels of amyoid-β1-42 peptide. For unclear reasons, mitochondrial biogenesis is suppressed in AD frontal cortex, leading to reduced mitochondrial mass and impaired mitochondrial respiratory capacity. Downregulation of antioxidant proteins further threatens neuronal function. Altering progression of AD appears to require both correction of impaired mitobiogenesis and restoration of antioxidant protection.
Collapse
Affiliation(s)
- Kisha J Young-Collier
- Neuroscience Graduate Program and Medical Scientist Training Program, University of Virginia School of Medicine, Charlottesville, VA, USA
| | | | | |
Collapse
|
25
|
Iyer S, Rao RR, Gnaiger E, Bennett JP. Mitochondrial gene therapy improves respiration and biogenesis in mitochondrial diseases of children and adults. Mitochondrion 2012. [DOI: 10.1016/j.mito.2012.07.026] [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: 10/27/2022]
|
26
|
Abstract
The prion diseases sheep scrapie and cervid chronic wasting disease are transmitted, in part, via an environmental reservoir of infectivity; prions released from infected animals persist in the environment and can cause disease years later. Central to controlling disease transmission is the identification of methods capable of inactivating these agents on the landscape. We have found that certain lichens, common, ubiquitous, symbiotic organisms, possess a serine protease capable of degrading prion protein (PrP) from prion-infected animals. The protease functions against a range of prion strains from various hosts and reduces levels of abnormal PrP by at least two logs. We have now tested more than twenty lichen species from several geographical locations and from various taxa and found that approximately half of these species degrade PrP. Critical next steps include examining the effect of lichens on prion infectivity and cloning the protease responsible for PrP degradation. The impact of lichens on prions in the environment remains unknown. We speculate that lichens could have the potential to degrade prions when they are shed from infected animals onto lichens or into environments where lichens are abundant. In addition, lichens are frequently consumed by cervids and many other animals and the effect of dietary lichens on prion disease transmission should also be considered.
Collapse
Affiliation(s)
- Cynthia M Rodriguez
- USGS National Wildlife Health Center; Department of Bacteriology, University of Wisconsin, Madison, WI, USA
| | | | | |
Collapse
|
27
|
Iyer S, Xiao E, Alsayegh K, Eroshenko N, Riggs MJ, Bennett JP, Rao RR. Mitochondrial gene replacement in human pluripotent stem cell-derived neural progenitors. Gene Ther 2012; 19:469-75. [PMID: 21918550 PMCID: PMC11071659 DOI: 10.1038/gt.2011.134] [Citation(s) in RCA: 18] [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: 03/14/2011] [Revised: 07/13/2011] [Accepted: 08/05/2011] [Indexed: 12/22/2022]
Abstract
Human pluripotent stem cell-derived neural progenitor (hNP) cells are an excellent resource for understanding early neural development and neurodegenerative disorders. Given that many neurodegenerative disorders can be correlated with defects in the mitochondrial genome, optimal utilization of hNP cells requires an ability to manipulate and monitor changes in the mitochondria. Here, we describe a novel approach that uses recombinant human mitochondrial transcription factor A (rhTFAM) protein to transfect and express a pathogenic mitochondrial genome (mtDNA) carrying the G11778A mutation associated with Leber's hereditary optic neuropathy (LHON) disease, into dideoxycytidine (ddC)-treated hNPs. Treatment with ddC reduced endogenous mtDNA and gene expression, without loss of hNP phenotypic markers. Entry of G11778A mtDNA complexed with the rhTFAM was observed in mitochondria of ddC-hNPs. Expression of the pathogenic RNA was confirmed by restriction enzyme analysis of the SfaN1-digested cDNA. On the basis of the expression of neuron-specific class III beta-tubulin, neuronal differentiation occurred. Our results show for the first time that pathogenic mtDNA can be introduced and expressed into hNPs without loss of phenotype or neuronal differentiation potential. This mitochondrial gene replacement technology allows for creation of in vitro stem cell-based models useful for understanding neuronal development and treatment of neurodegenerative disorders.
Collapse
Affiliation(s)
- S Iyer
- Center for the Study of Biological Complexity, Life Sciences Program, Virginia Commonwealth University, Richmond, VA, USA
| | - E Xiao
- Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA, USA
- Current address: Neuroimaging Core; Genes, Cognition, and Psychosis Program, National Institute of Mental Health, Bethesda, MD, USA
| | - K Alsayegh
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, VA, USA
| | - N Eroshenko
- Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA, USA
- School of Engineering and Applied Sciences, Harvard University, Boston, MA, USA
| | - MJ Riggs
- Integrated Life Sciences Program, Virginia Commonwealth University, Richmond, VA, USA
| | - JP Bennett
- Parkinson’s Disease Center, Virginia Commonwealth University, Richmond, VA, USA
- Department of Neurology, Virginia Commonwealth University, Richmond, VA, USA
| | - RR Rao
- Center for the Study of Biological Complexity, Life Sciences Program, Virginia Commonwealth University, Richmond, VA, USA
- Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA, USA
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, VA, USA
- Integrated Life Sciences Program, Virginia Commonwealth University, Richmond, VA, USA
| |
Collapse
|
28
|
Iyer S, Bergquist K, Young K, Gnaiger E, Rao RR, Bennett JP. Mitochondrial gene therapy improves respiration, biogenesis, and transcription in G11778A Leber's hereditary optic neuropathy and T8993G Leigh's syndrome cells. Hum Gene Ther 2012; 23:647-57. [PMID: 22390282 DOI: 10.1089/hum.2011.177] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Many incurable mitochondrial disorders result from mutant mitochondrial DNA (mtDNA) and impaired respiration. Leigh's syndrome (LS) is a fatal neurodegenerative disorder of infants, and Leber's hereditary optic neuropathy (LHON) causes blindness in young adults. Treatment of LHON and LS cells harboring G11778A and T8993G mutant mtDNA, respectively, by >90%, with healthy donor mtDNA complexed with recombinant human mitochondrial transcription factor A (rhTFAM), improved mitochondrial respiration by ∼1.2-fold in LHON cells and restored >50% ATP synthase function in LS cells. Mitochondrial replication, transcription, and translation of key respiratory genes and proteins were increased in the short term. Increased NRF1, TFAMB1, and TFAMA expression alluded to the activation of mitochondrial biogenesis as a mechanism for improving mitochondrial respiration. These results represent the development of a therapeutic approach for LHON and LS patients in the near future.
Collapse
Affiliation(s)
- Shilpa Iyer
- Center for the Study of Biological Complexity, Life Sciences, Virginia Commonwealth University, Richmond, VA 23284-3020, USA.
| | | | | | | | | | | |
Collapse
|
29
|
Johnson CJ, Bennett JP, Biro SM, Duque-Velasquez JC, Rodriguez CM, Bessen RA, Rocke TE. Degradation of the disease-associated prion protein by a serine protease from lichens. PLoS One 2011; 6:e19836. [PMID: 21589935 PMCID: PMC3092769 DOI: 10.1371/journal.pone.0019836] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Accepted: 04/18/2011] [Indexed: 11/19/2022] Open
Abstract
The disease-associated prion protein (PrPTSE), the probable
etiological agent of the transmissible spongiform encephalopathies (TSEs), is
resistant to degradation and can persist in the environment. Lichens,
mutualistic symbioses containing fungi, algae, bacteria and occasionally
cyanobacteria, are ubiquitous in the environment and have evolved unique
biological activities allowing their survival in challenging ecological niches.
We investigated PrPTSE inactivation by lichens and found acetone
extracts of three lichen species (Parmelia sulcata,
Cladonia rangiferina and Lobaria
pulmonaria) have the ability to degrade prion protein (PrP) from
TSE-infected hamsters, mice and deer. Immunoblots measuring PrP levels and
protein misfolding cyclic amplification indicated at least two logs of
reductions in PrPTSE. Degradative activity was not found in closely
related lichen species or in algae or a cyanobacterium that inhabit lichens.
Degradation was blocked by Pefabloc SC, a serine protease inhibitor, but not
inhibitors of other proteases or enzymes. Additionally, we found that PrP levels
in PrPTSE-enriched preps or infected brain homogenates are also
reduced following exposure to freshly-collected P. sulcata or
an aqueous extract of the lichen. Our findings indicate that these lichen
extracts efficiently degrade PrPTSE and suggest that some lichens
could have potential to inactivate TSE infectivity on the landscape or be a
source for agents to degrade prions. Further work to clone and characterize the
protease, assess its effect on TSE infectivity and determine which organism or
organisms present in lichens produce or influence the protease activity is
warranted.
Collapse
Affiliation(s)
- Christopher J Johnson
- Prion Research Laboratory, United States Geological Survey National Wildlife Health Center, Madison, Wisconsin, United States of America.
| | | | | | | | | | | | | |
Collapse
|
30
|
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized clinically by progressive decline in memory and cognition and pathologically by extracellular amyloid-beta (Abeta) deposits and intraneuronal aggregates of hyperphosphorylated tau. Since its proposal in 1992, the amyloid cascade hypothesis implicates Abeta overproduction as a causative event in disease pathogenesis, and this thinking has predominated the field's understanding of AD pathogenesis and the development of potential therapeutics (i.e., Abeta-reducing agents). Though Abeta has been shown to induce AD pathology, unanswered questions for sporadic AD development suggests this hypothesis is best applied to familial disease only. The more recent mitochondrial cascade hypothesis is supported by data showing that early impairments of mitochondrial dysfunction and oxidative stress may precede Abeta overproduction and deposition. However, the development of Abeta-reducing agents continues. Unfortunately, these agents have not been efficiently tested for their effect on one of the earliest AD pathologies, i.e., mitochondrial dysfunction. This paper will review supporting data for the amyloid and mitochondrial cascade hypotheses, reports of the effects of secretase inhibitors on AD-phenotypic cells and animals, and begin to look at a potential role for gamma-secretase, which is localized to mitochondria, in AD-related mitochondrial dysfunction.
Collapse
Affiliation(s)
- Kisha J Young
- Neuroscience Graduate Program and Medical Scientist Training Program, University of Virginia School of Medicine, Charlottesville, VA, USA
| | | |
Collapse
|
31
|
Thomas RR, Khan SM, Portell FR, Smigrodzki RM, Bennett JP. Recombinant human mitochondrial transcription factor A stimulates mitochondrial biogenesis and ATP synthesis, improves motor function after MPTP, reduces oxidative stress and increases survival after endotoxin. Mitochondrion 2010; 11:108-18. [PMID: 20727424 DOI: 10.1016/j.mito.2010.08.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Revised: 07/15/2010] [Accepted: 08/06/2010] [Indexed: 11/17/2022]
Abstract
Recombinant human mitochondrial transcription factor A protein (rhTFAM) was evaluated for its acute effects on cultured cells and chronic effects in mice. Fibroblasts incubated with rhTFAM acutely increased respiration in a chloramphenicol-sensitive manner. SH-SY5Y cells showed rhTFAM concentration-dependent reduction of methylpyridinium (MPP(+))-induced oxidative stress and increases in lowered ATP levels and viability. Mice treated with weekly i.v. rhTFAM showed increased mitochondrial gene copy number, complex I protein levels and ATP production rates; oxidative damage to proteins was decreased ~50%. rhTFAM treatment improved motor recovery rate after treatment with MPTP and dose-dependently improved survival in the lipopolysaccharide model of endotoxin sepsis.
Collapse
Affiliation(s)
- Ravindar R Thomas
- Morris Udall Parkinson's Disease Research Center of Excellence, University of Virginia, Charlottesville, VA, United States
| | | | | | | | | |
Collapse
|
32
|
Onyango IG, Ahn JY, Tuttle JB, Bennett JP, Swerdlow RH. Nerve growth factor attenuates oxidant-induced β-amyloid neurotoxicity in sporadic Alzheimer's disease cybrids. J Neurochem 2010; 114:1605-18. [PMID: 20561151 DOI: 10.1111/j.1471-4159.2010.06871.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Although mitochondrial dysfunction has been linked to Alzheimer's disease (AD), it is not fully understood how this dysfunction may induce neuronal death. In this study, we show that transmitochondrial hybrid cells (cybrids) expressing mitochondrial genes from patients with sporadic AD (SAD) have substantial alterations in basal upstream tyrosine kinase signaling and downstream serine-threonine kinase signaling that are mediated by intracellular free radicals. This is associated with reduced tropomyocin receptor kinase (TrkA) and p75 neurotrophin receptor receptor expression that profoundly alters nerve growth factor signaling, increases generation of Aβ and decreases viability. Many of these observed effects in SAD cybrids would be predicted to increase risk of premature neuronal death and reduce resistance to stressors and add further support for the pathogenic role of mtDNA expression in the pathogenesis of SAD.
Collapse
Affiliation(s)
- Isaac G Onyango
- Department of Neurology, University of Kansas Medical Center, Kansas City, Kansas, USA.
| | | | | | | | | |
Collapse
|
33
|
Keeney PM, Bennett JP. ALS spinal neurons show varied and reduced mtDNA gene copy numbers and increased mtDNA gene deletions. Mol Neurodegener 2010; 5:21. [PMID: 20504367 PMCID: PMC2889994 DOI: 10.1186/1750-1326-5-21] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [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: 04/13/2010] [Accepted: 05/26/2010] [Indexed: 12/13/2022] Open
Abstract
Background Spinal cord neurons of ALS patients demonstrate reduced cytochrome oxidase histochemical activity, and ALS spinal cord tissues have increased mitochondrial DNA (mtDNA) point mutations and depleted mtDNA levels. It is presently unknown whether mtDNA abnormalities are present in single human ALS neurons. Results Using laser capture microdissection (LCM) we isolated several hundred individual anterior spinal neurons from unfixed, frozen sections of 10 ALS and 7 age-matched CTL cervical spinal cords. DNA from each individual neuron was analyzed with multiplex qPCR for ND2, CO3, and ND4, three mitochondrial DNA genes encoding respiratory proteins. Scatterplots of individual spinal neuron results showed extensive heterogeneity of mtDNA gene levels across 4-5 orders of magnitude that were much more clustered in single Purkinje neurons isolated from CTL cerebella. Plots of ratios of ND4/ND2 and CO3/ND2 showed that many but not all ALS neurons from individuals contained low ratios of these mtDNA genes, implying greater abundances of mtDNA deletions in the major arc. Single CTL cerebellar Purkinje neurons did not contain high levels of apparent mtDNA deletions observed in anterior spinal neurons. Conclusions At the time of ALS subjects' deaths, many but not all surviving anterior neurons in their cervical spinal cords have reduced mtDNA gene levels and increased mtDNA deletion abundances that arise for unclear reasons. If these anterior spinal neuron mtDNA gene deficiencies contribute to bioenergetic impairments, reduced synaptic function and increased risk of degeneration, then introduction into mitochondria and expression of intact mtDNA, now available through use of recently developed recombinant human TFAM, may reverse the course of ALS.
Collapse
Affiliation(s)
- Paula M Keeney
- Department of Neurology, University of Virginia, Charlottesville, Virginia, USA.
| | | |
Collapse
|
34
|
Keeney PM, Quigley CK, Dunham LD, Papageorge CM, Iyer S, Thomas RR, Schwarz KM, Trimmer PA, Khan SM, Portell FR, Bergquist KE, Bennett JP. Mitochondrial gene therapy augments mitochondrial physiology in a Parkinson's disease cell model. Hum Gene Ther 2009; 20:897-907. [PMID: 19374590 DOI: 10.1089/hum.2009.023] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Neurodegeneration in Parkinson's disease (PD) affects mainly dopaminergic neurons in the substantia nigra, where age-related, increasing percentages of cells lose detectable respiratory activity associated with depletion of intact mitochondrial DNA (mtDNA). Replenishment of mtDNA might improve neuronal bioenergetic function and prevent further cell death. We developed a technology ("ProtoFection") that uses recombinant human mitochondrial transcription factor A (TFAM) engineered with an N-terminal protein transduction domain (PTD) followed by the SOD2 mitochondrial localization signal (MLS) to deliver mtDNA cargo to the mitochondria of living cells. MTD-TFAM (MTD = PTD + MLS = "mitochondrial transduction domain") binds mtDNA and rapidly transports it across plasma membranes to mitochondria. For therapeutic proof-of-principle we tested ProtoFection technology in Parkinson's disease cybrid cells, using mtDNA generated from commercially available human genomic DNA (gDNA; Roche). Nine to 11 weeks after single exposures to MTD-TFAM + mtDNA complex, PD cybrid cells with impaired respiration and reduced mtDNA genes increased their mtDNA gene copy numbers up to 24-fold, mtDNA-derived RNAs up to 35-fold, TFAM and ETC proteins, cell respiration, and mitochondrial movement velocities. Cybrid cells with no or minimal basal mitochondrial impairments showed reduced or no responses to treatment, suggesting the possibility of therapeutic selectivity. Exposure of PD but not control cybrid cells to MTD-TFAM protein alone or MTD-TFAM + mtDNA complex increased expression of PGC-1alpha, suggesting activation of mitochondrial biogenesis. ProtoFection technology for mitochondrial gene therapy holds promise for improving bioenergetic function in impaired PD neurons and needs additional development to define its pharmacodynamics and delineate its molecular mechanisms. It also is unclear whether single-donor gDNA for generating mtDNA would be a preferred therapeutic compared with the pooled gDNA used in this study.
Collapse
Affiliation(s)
- Paula M Keeney
- Morris K. Udall Parkinson's Disease Research Center of Excellence, University of Virginia, Charlottesville, VA 22908, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Keeney PM, Dunham LD, Quigley CK, Morton SL, Bergquist KE, Bennett JP. Cybrid models of Parkinson's disease show variable mitochondrial biogenesis and genotype-respiration relationships. Exp Neurol 2009; 220:374-82. [PMID: 19815014 DOI: 10.1016/j.expneurol.2009.09.025] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2009] [Revised: 09/23/2009] [Accepted: 09/28/2009] [Indexed: 01/01/2023]
Abstract
Sporadic Parkinson's disease (sPD) is a nervous system-wide disease that presents with a bradykinetic movement disorder and frequently progresses to include depression and cognitive impairment. Cybrid models of sPD are based on expression of sPD platelet mitochondrial DNA (mtDNA) in neural cells and demonstrate some similarities to sPD brains. In sPD and CTL cybrids we characterized aspects of mitochondrial biogenesis, mtDNA genomics, composition of the respirasome and the relationships among isolated mitochondrial and intact cell respiration. Cybrid mtDNA levels varied and correlated with expression of PGC-1 alpha, a transcriptional co-activator regulator of mitochondrial biogenesis. Levels of mtDNA heteroplasmic mutations were asymmetrically distributed across the mitochondrial genome; numbers of heteroplasmies were more evenly distributed. Neither levels nor numbers of heteroplasmies distinguished sPD from CTL. sPD cybrid mitochondrial ETC subunit protein levels were not altered. Isolated mitochondrial complex I respiration rates showed limited correlation with whole cell complex I respiration rates in both sPD and CTL cybrids. Intact cell respiration during the normoxic-anoxic transition yielded K(m) values for oxygen that directly related to respiration rates in CTL but not in sPD cell lines. Both sPD and CTL cybrid cells are substantially heterogeneous in mitochondrial genomic and physiologic properties. Our results suggest that mtDNA depletion may occur in sPD neurons and could reflect impairment of mitochondrial biogenesis. Cybrids remain a valuable model for some aspects of sPD but their heterogeneity mitigates against a simple designation of sPD phenotype in this cell model.
Collapse
Affiliation(s)
- Paula M Keeney
- Morris K. Udall Parkinson's Research Center of Excellence, University of Virginia, PO Box 800394, Charlottesville, VA 22908, USA
| | | | | | | | | | | |
Collapse
|
36
|
Arthur CR, Morton SL, Dunham LD, Keeney PM, Bennett JP. Parkinson's disease brain mitochondria have impaired respirasome assembly, age-related increases in distribution of oxidative damage to mtDNA and no differences in heteroplasmic mtDNA mutation abundance. Mol Neurodegener 2009; 4:37. [PMID: 19775436 PMCID: PMC2761382 DOI: 10.1186/1750-1326-4-37] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [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: 08/12/2009] [Accepted: 09/23/2009] [Indexed: 12/21/2022] Open
Abstract
Background Sporadic Parkinson's disease (sPD) is a nervous system-wide disease that presents with a bradykinetic movement disorder and is frequently complicated by depression and cognitive impairment. sPD likely has multiple interacting causes that include increased oxidative stress damage to mitochondrial components and reduced mitochondrial bioenergetic capacity. We analyzed mitochondria from postmortem sPD and CTL brains for evidence of oxidative damage to mitochondrial DNA (mtDNA), heteroplasmic mtDNA point mutations and levels of electron transport chain proteins. We sought to determine if sPD brains possess any mtDNA genotype-respiratory phenotype relationships. Results Treatment of sPD brain mtDNA with the mitochondrial base-excision repair enzyme 8-oxyguanosine glycosylase-1 (hOGG1) inhibited, in an age-dependent manner, qPCR amplification of overlapping ~2 kbase products; amplification of CTL brain mtDNA showed moderate sensitivity to hOGG1 not dependent on donor age. hOGG1 mRNA expression was not different between sPD and CTL brains. Heteroplasmy analysis of brain mtDNA using Surveyor nuclease® showed asymmetric distributions and levels of heteroplasmic mutations across mtDNA but no patterns that statistically distinguished sPD from CTL. sPD brain mitochondria displayed reductions of nine respirasome proteins (respiratory complexes I-V). Reduced levels of sPD brain mitochondrial complex II, III and V, but not complex I or IV proteins, correlated closely with rates of NADH-driven electron flow. mtDNA levels and PGC-1α expression did not differ between sPD and CTL brains. Conclusion PD brain mitochondria have reduced mitochondrial respiratory protein levels in complexes I-V, implying a generalized defect in respirasome assembly. These deficiencies do not appear to arise from altered point mutational burden in mtDNA or reduction of nuclear signaling for mitochondrial biogenesis, implying downstream etiologies. The origin of age-related increases in distribution of oxidative mtDNA damage in sPD but not CTL brains is not clear, tracks with but does not determine the sPD phenotype, and may indicate a unique consequence of aging present in sPD that could contribute to mtDNA deletion generation in addition to mtDNA replication, transcription and sequencing errors. sPD frontal cortex experiences a generalized bioenergetic deficiency above and beyond aging that could contribute to mood disorders and cognitive impairments.
Collapse
Affiliation(s)
- Charles R Arthur
- Morris K Udall Parkinson's Disease Research Center of Excellence, University of Virginia School of Medicine, Charlottesville, VA 22908, USA.
| | | | | | | | | |
Collapse
|
37
|
Abstract
Parkinson's disease (PD) is the eponym attached to the most prevalent neurodegenerative movement disorder of adults, derived from observations of an early nineteenth century physician and paleontologist, James Parkinson, and is now recognized to encompass much more than a movement disorder clinically or dopamine neuron death pathologically. Most PD ( approximately 90%) is sporadic (sPD), is associated with mitochondrial deficiencies and has been studied in cell and animal models arising from the use of mitochondrial toxins that unfortunately have not predicted clinical efficacy to slow disease progression in humans. We have extensively studied the cytoplasmic hybrid ("cybrid") model of sPD in which donor mtDNAs are introduced into and expressed in neural tumor cells with identical nuclear genetic and environmental backgrounds. sPD cybrids demonstrate many abnormalities in which increased oxidative stress drives downstream antioxidant response and cell death activating signaling pathways. sPD cybrids regulate mitochondrial ETC genes and gene ontology families like sPD brain. sPD cybrids spontaneously form Lewy bodies and Lewy neurites, linking mtDNA expression to neuropathology, and demonstrate impaired organelle transport in processes and reduced mitochondrial respiration. Our recent studies show that near-infrared laser light therapy normalizes mitochondrial movement and can stimulate respiration in sPD cybrid neurons, and mitochondrial gene therapy can restore respiration and stimulate mitochondrial ETC gene and protein expression. sPD cybrids have provided multiple lines of circumstantial evidence linking mtDNA to sPD pathogenesis and can serve as platforms for therapy development. sPD cybrid models can be improved by the use of non-tumor human stem cell-derived neural precursor cells and by an introduction of postmortem brain mtDNA to test its causality directly.
Collapse
Affiliation(s)
- Patricia A Trimmer
- Morris K. Udall Parkinson's Disease Research Center of Excellence, Department of Neurology, University of Virginia, Charlottesville, 22908, USA.
| | | |
Collapse
|
38
|
Wang H, Larriviere KS, Keller KE, Ware KA, Burns TM, Conaway MA, Lacomis D, Pattee GL, Phillips LH, Solenski NJ, Zivkovic SA, Bennett JP. R(+) pramipexole as a mitochondrially focused neuroprotectant: Initial early phase studies in ALS. ACTA ACUST UNITED AC 2009; 9:50-8. [DOI: 10.1080/17482960701791234] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
39
|
Iyer S, Thomas RR, Portell FR, Dunham LD, Quigley CK, Bennett JP. Recombinant mitochondrial transcription factor A with N-terminal mitochondrial transduction domain increases respiration and mitochondrial gene expression. Mitochondrion 2009; 9:196-203. [PMID: 19460293 DOI: 10.1016/j.mito.2009.01.012] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2008] [Revised: 01/26/2009] [Accepted: 01/27/2009] [Indexed: 10/21/2022]
Abstract
We developed a scalable procedure to produce human mitochondrial transcription factor A (TFAM) modified with an N-terminal protein transduction domain (PTD) and mitochondrial localization signal (MLS) that allow it to cross membranes and enter mitochondria through its "mitochondrial transduction domain" (MTD=PTD+MLS). Alexa488-labeled MTD-TFAM rapidly entered the mitochondrial compartment of cybrid cells carrying the G11778A LHON mutation. MTD-TFAM reversibly increased respiration and levels of respiratory proteins. In vivo treatment of mice with MTD-TFAM increased motor endurance and complex I-driven respiration in mitochondria from brain and skeletal muscle. MTD-TFAM increases mitochondrial bioenergetics and holds promise for treatment of mitochondrial diseases involving deficiencies of energy production.
Collapse
Affiliation(s)
- Shilpa Iyer
- Center for the Study of Neurodegenerative Diseases and The Morris K. Udall Parkinson's Disease Research Center of Excellence, University of Virginia, PO Box 800394, Charlottesville, VA 22908, United States
| | | | | | | | | | | |
Collapse
|
40
|
Iyer S, Khan S, Portell F, Thomas R, Borland K, Quigley C, Dunham L, Bennett JP. 5. Protein-mediated mtDNA Transfection (“Protofection®”) Increases Respiration and Mitochondrial DNA Gene Copy Numbers and Expression in G11778A LHON Cybrids. Mitochondrion 2009. [DOI: 10.1016/j.mito.2008.12.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
41
|
Borland MK, Trimmer PA, Rubinstein JD, Keeney PM, Mohanakumar K, Liu L, Bennett JP. Chronic, low-dose rotenone reproduces Lewy neurites found in early stages of Parkinson's disease, reduces mitochondrial movement and slowly kills differentiated SH-SY5Y neural cells. Mol Neurodegener 2008; 3:21. [PMID: 19114014 PMCID: PMC2631511 DOI: 10.1186/1750-1326-3-21] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [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: 11/20/2008] [Accepted: 12/29/2008] [Indexed: 11/30/2022] Open
Abstract
Background Parkinson's disease, the most common adult neurodegenerative movement disorder, demonstrates a brain-wide pathology that begins pre-clinically with alpha-synuclein aggregates ("Lewy neurites") in processes of gut enteric and vagal motor neurons. Rostral progression into substantia nigra with death of dopamine neurons produces the motor impairment phenotype that yields a clinical diagnosis. The vast majority of Parkinson's disease occurs sporadically, and current models of sporadic Parkinson's disease (sPD) can utilize directly infused or systemic neurotoxins. Results We developed a differentiation protocol for human SH-SY5Y neuroblastoma that yielded non-dividing dopaminergic neural cells with long processes that we then exposed to 50 nM rotenone, a complex I inhibitor used in Parkinson's disease models. After 21 days of rotenone, ~60% of cells died. Their processes retracted and accumulated ASYN-(+) and UB-(+) aggregates that blocked organelle transport. Mitochondrial movement velocities were reduced by 8 days of rotenone and continued to decline over time. No cytoplasmic inclusions resembling Lewy bodies were observed. Gene microarray analyses showed that the majority of genes were under-expressed. qPCR analyses of 11 mtDNA-encoded and 10 nDNA-encoded mitochondrial electron transport chain RNAs' relative expressions revealed small increases in mtDNA-encoded genes and lesser regulation of nDNA-encoded ETC genes. Conclusion Subacute rotenone treatment of differentiated SH-SY5Y neuroblastoma cells causes process retraction and partial death over several weeks, slowed mitochondrial movement in processes and appears to reproduce the Lewy neuritic changes of early Parkinson's disease pathology but does not cause Lewy body inclusions. The overall pattern of transcriptional regulation is gene under-expression with minimal regulation of ETC genes in spite of rotenone's being a complex I toxin. This rotenone-SH-SY5Y model in a differentiated human neural cell mimics changes of early Parkinson's disease and may be useful for screening therapeutics for neuroprotection in that disease stage.
Collapse
Affiliation(s)
- M Kathleen Borland
- Center for the Study of Neurodegenerative Diseases and Morris K, Udall Parkinson's Disease Research Center of Excellence, University of Virginia, Charlottesville, Virginia, USA.
| | | | | | | | | | | | | |
Collapse
|
42
|
Oliveira AP, Pampulha ME, Bennett JP. A two-year field study with transgenic Bacillus thuringiensis maize: effects on soil microorganisms. Sci Total Environ 2008; 405:351-357. [PMID: 18656246 DOI: 10.1016/j.scitotenv.2008.05.046] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2007] [Revised: 04/04/2008] [Accepted: 05/30/2008] [Indexed: 05/26/2023]
Abstract
We evaluated the changes of some soil microbiological characteristics due to the use of transgenic maize expressing Bacillus thuringiensis (Bt) toxin. A two-year field experiment was conducted (2003 and 2004). Two lines of transgenic Bt maize that express the Cry1Ab protein (event 176 and MON 810) and their near-isogenic non-Bt lines were used. Rhizosphere and non-rhizosphere soils were collected and measurements were performed during the maize cultural cycle and immediately at pre-harvest. Key soil microbiological parameters measured included the numbers of culturable aerobic bacteria, including actinomycetes, and fungi, the activity of dehydrogenase and nitrogenase enzymes and ATP content. There were clear seasonal effects in the microbial parameters as evidenced by the consistent changes in sampling dates across the two years. Differences in the measured variables were also observed between rhizosphere and non-rhizosphere soils. However, under our field conditions, the presence of Bt maize did not cause, in a general way, changes in the microbial populations of the soil or in the activity of the microbial community.
Collapse
Affiliation(s)
- Adília P Oliveira
- Departamento de Botânica e Engenharia Biológica, Instituto Superior de Agronomia, Universidade Técnica de Lisboa (UTLisbon), Tapada da Ajuda, Lisboa, Portugal.
| | | | | |
Collapse
|
43
|
Borland MK, Mohanakumar KP, Rubinstein JD, Keeney PM, Xie J, Capaldi R, Dunham LD, Trimmer PA, Bennett JP. Relationships among molecular genetic and respiratory properties of Parkinson's disease cybrid cells show similarities to Parkinson's brain tissues. Biochim Biophys Acta Mol Basis Dis 2008; 1792:68-74. [PMID: 18973805 DOI: 10.1016/j.bbadis.2008.09.014] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2008] [Revised: 09/10/2008] [Accepted: 09/24/2008] [Indexed: 12/01/2022]
Abstract
We have studied sporadic Parkinson's disease (sPD) from expression of patient mitochondrial DNA (mtDNA) in neural cells devoid of their own mtDNA, the "cybrid" model. In spite of reproducing several properties of sPD brain, it remains unclear whether sPD cybrid cells reflect more complex sPD brain bioenergetic pathophysiology. We characterized and correlated respiration of intact sPD cybrid cells with electron transport chain (ETC) protein assembly, complex I ETC gene expression and ETC protein levels in sPD brain. We also assayed expression for multiple ETC genes coded by mtDNA and nuclear DNA (nDNA) in sPD cybrid cells and brain. sPD cybrid cells have reduced levels of mtDNA genes, variable compensatory normalization of mitochondrial gene expression and show robust correlations with mitochondrial ETC gene expression in sPD brains. Relationships among ETC protein levels predict impaired complex I-mediated respiration in sPD brain. That sPD cybrid cells and sPD brain samples show very correlated regulation of nDNA and mtDNA ETC transcriptomes suggests similar bioenergetic physiologies. We propose that further insights into sPD pathogenesis will follow elucidation of mechanisms leading to reduced mtDNA gene levels in sPD cybrids. This will require characterization of the abnormalities and dynamics of mtDNA changes propagated through sPD cybrids over time.
Collapse
Affiliation(s)
- M Kathleen Borland
- Center for the Study of Neurodegenerative Diseases, University of Virginia, Charlottesville, Virginia, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Ayrault S, Clochiatti R, Carrot F, Daudin L, Bennett JP. Factors to consider for trace element deposition biomonitoring surveys with lichen transplants. Sci Total Environ 2007; 372:717-27. [PMID: 17157898 DOI: 10.1016/j.scitotenv.2006.10.032] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2006] [Revised: 09/27/2006] [Accepted: 10/18/2006] [Indexed: 05/12/2023]
Abstract
A trace element deposition biomonitoring experiment with transplants of the fruticose lichen Evernia prunastri was developed, aimed at monitoring the effects of different exposure parameters (exposure orientation and direct rain) and to the elements Ti, V, Cr, Co, Cu, Zn, Rb, Cd, Sb and Pb. Accumulations were observed for most of the elements, confirming the ability of Evernia transplants for atmospheric metal deposition monitoring. The accumulation trends were mainly affected by the exposure orientation and slightly less so by the protection from rain. The zonation of the trace elements inside the thallus was also studied. It was concluded that trace element concentrations were not homogeneous in Evernia, thus imposing some cautions on the sampling approach. A nuclear microprobe analysis of an E. prunastri transplanted thallus in thin cross-sections concluded that the trace elements were mainly concentrated on the cortex of the thallus, except Zn, Ca and K which were also present in the internal layers. The size of the particles deposited or entrapped on the cortex surface averaged 7 microm. A list of key parameters to ensure the comparability of surveys aiming at observing temporal or spatial deposition variation is presented.
Collapse
Affiliation(s)
- Sophie Ayrault
- Laboratoire des Sciences du Climat et de l'Environnement, CEA-CNRS-UVSQ, F-91198 Gif-sur-Yvette, France.
| | | | | | | | | |
Collapse
|
45
|
Bennett JP, Jepsen EA, Roth JA. Field responses of Prunus serotina and Asclepias syriaca to ozone around southern Lake Michigan. Environ Pollut 2006; 142:354-66. [PMID: 16343714 DOI: 10.1016/j.envpol.2005.09.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2005] [Revised: 08/23/2005] [Accepted: 09/27/2005] [Indexed: 05/05/2023]
Abstract
Higher ozone concentrations east of southern Lake Michigan compared to west of the lake were used to test hypotheses about injury and growth effects on two plant species. We measured approximately 1000 black cherry trees and over 3000 milkweed stems from 1999 to 2001 for this purpose. Black cherry branch elongation and milkweed growth and pod formation were significantly higher west of Lake Michigan while ozone injury was greater east of Lake Michigan. Using classification and regression tree (CART) analyses we determined that departures from normal precipitation, soil nitrogen and ozone exposure/peak hourly concentrations were the most important variables affecting cherry branch elongation, and milkweed stem height and pod formation. The effects of ozone were not consistently comparable with the effects of soil nutrients, weather, insect or disease injury, and depended on species. Ozone SUM06 exposures greater than 13 ppm-h decreased cherry branch elongation 18%; peak 1-h exposures greater than 93 ppb reduced milkweed stem height 13%; and peak 1-h concentrations greater than 98 ppb reduced pod formation 11% in milkweed.
Collapse
Affiliation(s)
- J P Bennett
- U.S. Geological Survey and Institute for Environmental Studies, University of Wisconsin, Madison, WI 53706, USA.
| | | | | |
Collapse
|
46
|
Keeney PM, Xie J, Capaldi RA, Bennett JP. Parkinson's disease brain mitochondrial complex I has oxidatively damaged subunits and is functionally impaired and misassembled. J Neurosci 2006; 26:5256-64. [PMID: 16687518 PMCID: PMC6674236 DOI: 10.1523/jneurosci.0984-06.2006] [Citation(s) in RCA: 536] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Loss of mitochondrial complex I catalytic activity in the electron transport chain (ETC) is found in multiple tissues from individuals with sporadic Parkinson's disease (PD) and is a property of some PD model neurotoxins. Using special ETC subunit-specific and complex I immunocapture antibodies directed against the entire complex I macroassembly, we quantified ETC proteins and protein oxidation of complex I subunits in brain mitochondria from 10 PD and 12 age-matched control (CTL) samples. We measured nicotinamide adenine dinucleotide (NADH)-driven electron transfer rates through complex I and correlated these with complex I subunit oxidation levels and reductions of its 8 kDa subunit. PD brain complex I shows 11% increase in ND6, 34% decrease in its 8 kDa subunit and contains 47% more protein carbonyls localized to catalytic subunits coded for by mitochondrial and nuclear genomes We found no changes in levels of ETC proteins from complexes II-V. Oxidative damage patterns to PD complex I are reproduced by incubation of CTL brain mitochondria with NADH in the presence of rotenone but not by exogenous oxidant. NADH-driven electron transfer rates through complex I inversely correlate with complex I protein oxidation status and positively correlate with reduction in PD 8 kDa subunit. Reduced complex I function in PD brain mitochondria appears to arise from oxidation of its catalytic subunits from internal processes, not from external oxidative stress, and correlates with complex I misassembly. This complex I auto-oxidation may derive from abnormalities in mitochondrial or nuclear encoded subunits, complex I assembly factors, rotenone-like complex I toxins, or some combination.
Collapse
|
47
|
Onyango IG, Tuttle JB, Bennett JP. Brain-derived growth factor and glial cell line-derived growth factor use distinct intracellular signaling pathways to protect PD cybrids from H2O2-induced neuronal death. Neurobiol Dis 2005; 20:141-54. [PMID: 16137575 DOI: 10.1016/j.nbd.2005.02.009] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [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] [Received: 09/20/2004] [Revised: 02/21/2005] [Accepted: 02/23/2005] [Indexed: 10/25/2022] Open
Abstract
The cause of idiopathic PD is obscure, and most cases are sporadic. Oxidative stress and deficiency of various neurotrophic factors (NTFs) could be factors triggering neurodegeneration in the substantia nigra (SN). Cytoplasmic hybrid cells (cybrids) made from mitochondrial DNA of idiopathic PD subjects have reduced glutathione (GSH) levels and increased vulnerability to H2O2. Brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) rescue PD cybrids from H2O2-induced cell death. GDNF mediated effects require Src kinase and phosphatidylinositol 3-kinase (PI3K)/Akt activation. Inhibiting either PI3K/Akt or ERK pathways blocks the effects of BDNF. Inhibiting p38MAPK and c-Jun N-terminal kinase (JNK) pathways enhances the neuroprotective effects of both NTFs. These results demonstrate that expression of PD mitochondrial genes in cybrids increases vulnerability to oxidative stress that is ameliorated by both BDNF and GDNF, which utilize distinct signaling cascades to increase intracellular GSH and enhance survival-promoting cell signaling.
Collapse
Affiliation(s)
- Isaac G Onyango
- Department of Neuroscience, University of Virginia School of Medicine, PO Box 801392, Charlottesville, VA 22908, USA.
| | | | | |
Collapse
|
48
|
Onyango IG, Tuttle JB, Bennett JP. Altered intracellular signaling and reduced viability of Alzheimer's disease neuronal cybrids is reproduced by beta-amyloid peptide acting through receptor for advanced glycation end products (RAGE). Mol Cell Neurosci 2005; 29:333-43. [PMID: 15911356 DOI: 10.1016/j.mcn.2005.02.012] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [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] [Received: 11/10/2004] [Revised: 01/24/2005] [Accepted: 02/22/2005] [Indexed: 11/22/2022] Open
Abstract
Activation of apoptosis by increased production of amyloid beta peptides (Abeta) has been implicated in neuronal cell death of Alzheimer's disease (AD). We used mitochondrial transgenic cybrid models of sporadic AD (SAD), which overproduce Abeta compared to control (CTL) cybrids, to investigate the effects of endogenously generated Abeta on intracellular signaling pathways and viability. Reducing SAD Abeta production with gamma-secretase inhibition altered the total phosphorylation profile of SAD cybrid to one similar to CTL cybrids and enhanced viability to approximately CTL cybrid levels. Treating CTL cybrids with exogenous Abeta or conditioned media (CM) from SAD cybrids activated the signaling pathways active in SAD cybrids under basal condition and decreased viability. Antibodies against receptor for advanced glycation end products (RAGE) blocked Abeta-induced activation of the p38, JNK pathways, and NF-kappaB in CTL cybrids and offered protection against the neurotoxic effects of Abeta. Expression of SAD mitochondrial genes in cybrids activates stress-related signaling pathways and reduces viability. This SAD phenotype is produced by endogenously generated Abeta and can be replicated by exogenous Abeta acting through RAGE.
Collapse
Affiliation(s)
- Isaac G Onyango
- Center for the Study of Neurodegenerative Diseases, University of Virginia School of Medicine, Charlottesville, VA 22908, USA.
| | | | | |
Collapse
|
49
|
Thiffault C, Bennett JP. Cyclical mitochondrial deltapsiM fluctuations linked to electron transport, F0F1 ATP-synthase and mitochondrial Na+/Ca+2 exchange are reduced in Alzheimer's disease cybrids. Mitochondrion 2005; 5:109-19. [PMID: 16050977 DOI: 10.1016/j.mito.2004.12.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [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] [Received: 06/09/2004] [Revised: 10/12/2004] [Accepted: 12/20/2004] [Indexed: 10/25/2022]
Abstract
Reduced complex IV, increased oxidative stress and beta amyloid peptide secretion in Alzheimer's disease (AD) can be replicated in cybrid models. We characterized cyclical mitochondrial deltapsiM fluctuations ('flickering') in neuroblastoma cells and AD/CTL cybrids. Flickering was blocked by ATP-synthase inhibition, was not observed in rho0 cells and was not blocked by antioxidant treatment. Flickering was not affected by the Ca(+2) uniporter antagonist Ru360 but was eliminated by BAPTA or CGP37137 blockade of the mitochondrial Na(+)/Ca(+2) exchanger. AD cybrid mitochondria showed reduced flickering. Flickering seems to represent coupling of deltapsiM to F0F1 ATP-synthase; reduction of flickering in AD cybrids suggests dysfunction of this coupling.
Collapse
Affiliation(s)
- Christine Thiffault
- Department of Neurology, Center for the Study of Neurodegenerative Diseases, University of Virginia, PO Box 800394, Charlottesville, VA 22908, USA
| | | |
Collapse
|
50
|
Onyango IG, Tuttle JB, Bennett JP. Activation of p38 and N-acetylcysteine-sensitive c-Jun NH2-terminal kinase signaling cascades is required for induction of apoptosis in Parkinson's disease cybrids. Mol Cell Neurosci 2005; 28:452-61. [PMID: 15737736 DOI: 10.1016/j.mcn.2004.10.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [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] [Received: 12/16/2003] [Revised: 10/08/2004] [Accepted: 10/12/2004] [Indexed: 11/16/2022] Open
Abstract
Cytoplasmic hybrid cells (cybrids) are created by selective amplification of mitochondrial genes against constant nuclear genetic and environmental backgrounds. Cybrids from patients with sporadic Parkinson's disease (PD) recapitulate disease features such as decreased complex I activity, increased oxidative stress, elevated activation of NF-kappaB, and production of Lewy body inclusions. We examined the activation of signaling pathways and NF-kappaB in PD cybrids after exposure to MAPK inhibitors and/or the antioxidant N-acetylcysteine (NAC). Under basal replicating conditions, PD cybrids have decreased viability that is associated with increased DNA condensation and poly-ADP ribose polymerase (PARP) cleavage as well as elevated p38 and JNK activity. Pharmacological inhibition of oxidative stress diminished the elevated p38, JNK activity and PARP cleavage, and enhanced PD cybrid viability. PD mitochondrial genes expressed in cybrids stimulate pro-apoptotic cell signaling and biochemistry through oxidative stress. These results support development of antioxidative therapeutics for PD.
Collapse
Affiliation(s)
- Isaac G Onyango
- Center for the Study of Neurodegenerative Diseases, University of Virginia School of Medicine, Charlottesville, Virginia 22908, USA.
| | | | | |
Collapse
|