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Glass TJ, Russell JA, Fisher EH, Ostadi M, Aori N, Yu YE, Connor NP. Altered tongue muscle contractile properties coincide with altered swallow function in the adult Ts65Dn mouse model of down syndrome. Front Neurol 2024; 15:1384572. [PMID: 38585362 PMCID: PMC10995394 DOI: 10.3389/fneur.2024.1384572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 03/08/2024] [Indexed: 04/09/2024] Open
Abstract
Purpose Down syndrome (DS) is a developmental disability associated with difficulties in deglutition. The adult Ts65Dn mouse model of DS has been previously shown to have differences in measures of swallowing compared with euploid controls. However, the putative mechanisms of these differences in swallowing function are unclear. This study tested the hypothesis that the Ts65Dn genotype is associated with atypical measures of tongue muscle contractile properties, coinciding with atypical swallow function. Methods Adult (5-month-old) Ts65Dn (n = 15 female, 14 male) and euploid sibling controls (n = 16 female, 14 male) were evaluated through videofluoroscopy swallow studies (VFSS) to quantify measures of swallowing performance including swallow rate and inter-swallow interval (ISI). After VFSS, retrusive tongue muscle contractile properties, including measures of muscle fatigue, were determined using bilateral hypoglossal nerve stimulation. Results The Ts65Dn group had significantly slower swallow rates, significantly greater ISI times, significantly slower rates of tongue force development, and significantly greater levels of tongue muscle fatigue, with lower retrusive tongue forces than controls in fatigue conditions. Conclusion Tongue muscle contractile properties are altered in adult Ts65Dn and coincide with altered swallow function.
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Affiliation(s)
- Tiffany J. Glass
- Department of Surgery, Division of Otolaryngology, University of Wisconsin-Madison, Madison, WI, United States
| | - John A. Russell
- Department of Surgery, Division of Otolaryngology, University of Wisconsin-Madison, Madison, WI, United States
| | - Erin H. Fisher
- Department of Surgery, Division of Otolaryngology, University of Wisconsin-Madison, Madison, WI, United States
| | - Marziyeh Ostadi
- Department of Surgery, Division of Otolaryngology, University of Wisconsin-Madison, Madison, WI, United States
- Department of Communication Sciences and Disorders, University of Wisconsin-Madison, Madison, WI, United States
| | - Nanyumuzi Aori
- Department of Surgery, Division of Otolaryngology, University of Wisconsin-Madison, Madison, WI, United States
| | - Y. Eugene Yu
- The Children’s Guild Foundation Down Syndrome Research Program, Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center, Buffalo, NY, United States
- Genetics, Genomics and Bioinformatics Program, State University of New York at Buffalo, Buffalo, NY, United States
| | - Nadine P. Connor
- Department of Surgery, Division of Otolaryngology, University of Wisconsin-Madison, Madison, WI, United States
- Department of Communication Sciences and Disorders, University of Wisconsin-Madison, Madison, WI, United States
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2
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Cisterna B, Boschi F, Lacavalla MA, Vattemi GNA, Zancanaro C, Malatesta M. Physical training promotes remodeling of the skeletal muscle extracellular matrix: An ultrastructural study in a murine model of Down syndrome. Microsc Res Tech 2023; 86:1517-1528. [PMID: 37381675 DOI: 10.1002/jemt.24379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 06/15/2023] [Accepted: 06/16/2023] [Indexed: 06/30/2023]
Abstract
Down syndrome (DS) is a genetically based disease caused by triplication of chromosome 21. DS is characterized by multi-systemic premature aging associated with deficit in motor coordination, balance, and postural control. Using a morphological, morphometrical, and immunocytochemical ultrastructural approach, this study investigated in vastus lateralis muscle of Ts65Dn mouse, a murine model of DS, the effect of an adapted physical training on the extracellular matrix (ECM) characteristics and whether the forecasted exercise-induced ECM remodeling impacts on sarcomere organization. Morphometry demonstrated thicker basement membrane and larger collagen bundles with larger interfibrillar spacing as well as irregularly arrayed myofibrils and lower telethonin density on Z-lines in trisomic versus euploid sedentary mice. In agreement with the multi-systemic premature aging described in DS, these ECM alterations were similar to those previously observed in skeletal muscle of aged mice. Adapted physical training induced remodeling of ECM in both trisomic and euploid mice, that is, enlargement of the collagen bundles associated with hypertrophy of collagen fibrils and reduction of the interfibrillar spacing. A re-alignment of the myofibrils and a higher telethonin density on Z-line was found in trisomic mice. Altogether, our findings suggest that physical training is an effective tool in limiting/counteracting the trisomy-associated musculoskeletal structural anomalies. The current findings constitute a solid experimental background for further study investigating the possible positive effect of physical training on skeletal muscle performance. RESEARCH HIGHLIGHTS: Vastus lateralis muscle of trisomic mice shows aging-like alterations of extracellular matrix. Training promotes extracellular matrix remodeling. Training may be an effective tool to counteract trisomy-associated alterations of skeletal muscle.
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Affiliation(s)
- Barbara Cisterna
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Federico Boschi
- Department of Engineering for Innovation Medicine, University of Verona, Verona, Italy
| | - Maria Assunta Lacavalla
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | | | - Carlo Zancanaro
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Manuela Malatesta
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
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3
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DeRuisseau LR, Receno CN, Cunningham C, Bates ML, Goodell M, Liang C, Eassa B, Pascolla J, DeRuisseau KC. Breathing and Oxygen Carrying Capacity in Ts65Dn and Down Syndrome. FUNCTION 2023; 4:zqad058. [PMID: 37954975 PMCID: PMC10634617 DOI: 10.1093/function/zqad058] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 09/29/2023] [Accepted: 10/03/2023] [Indexed: 11/14/2023] Open
Abstract
Individuals with Down syndrome (Ds) are at increased risk of respiratory infection, aspiration pneumonia, and apnea. The Ts65Dn mouse is a commonly used model of Ds, but there have been no formal investigations of awake breathing and respiratory muscle function in these mice. We hypothesized that breathing would be impaired in Ts65Dn vs. wild-type (WT), and would be mediated by both neural and muscular inputs. Baseline minute ventilation was not different at 3, 6, or 12 mo of age. However, VT/Ti, a marker of the neural drive to breathe, was lower in Ts65Dn vs. WT and central apneas were more prevalent. The response to breathing hypoxia was not different, but the response to hypercapnia was attenuated, revealing a difference in carbon dioxide sensing, and/or motor output in Ts65Dn. Oxygen desaturations were present in room air, demonstrating that ventilation may not be sufficient to maintain adequate oxygen saturation in Ts65Dn. We observed no differences in arterial PO2 or PCO2, but Ts65Dn had lower hemoglobin and hematocrit. A retrospective medical record review of 52,346 Ds and 52,346 controls confirmed an elevated relative risk of anemia in Ds. We also performed eupneic in-vivo electromyography and in-vitro muscle function and histological fiber typing of the diaphragm, and found no difference between strains. Overall, conscious respiration is impaired in Ts65Dn, is mediated by neural mechanisms, and results in reduced hemoglobin saturation. Oxygen carrying capacity is reduced in Ts65Dn vs. WT, and we demonstrate that individuals with Ds are also at increased risk of anemia.
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Affiliation(s)
- Lara R DeRuisseau
- Department of Basic Sciences, University of Health Sciences and Pharmacy, St. Louis, MO 63110, USA
| | - Candace N Receno
- Department of Exercise Science and Athletic Training, Ithaca College, Ithaca, NY 14850, USA
| | - Caitlin Cunningham
- Department of Statistics, Mathematics and Computer Science, Le Moyne College, Syracuse, NY 13214, USA
| | - Melissa L Bates
- Departments of Health and Human Physiology, Internal Medicine, and the Stead Family Department of Pediatrics, University of Iowa, Iowa City, IA 52242, USA
| | - Morgan Goodell
- Lake Erie College of Osteopathic Medicine, Elmira, NY 14901, USA
| | - Chen Liang
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY 14642,USA
| | - Brianna Eassa
- Department of Biological Sciences, Le Moyne College, Syracuse, NY 13214, USA
| | - Jessica Pascolla
- Department of Basic Sciences, University of Health Sciences and Pharmacy, St. Louis, MO 63110, USA
| | - Keith C DeRuisseau
- Department of Basic Sciences, University of Health Sciences and Pharmacy, St. Louis, MO 63110, USA
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4
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Boschi F. How to estimate the sarcomere size based on oblique sections of skeletal muscle. J Anat 2023; 243:648-657. [PMID: 37243921 PMCID: PMC10485579 DOI: 10.1111/joa.13892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 05/02/2023] [Accepted: 05/17/2023] [Indexed: 05/29/2023] Open
Abstract
Ultrastructural analysis of muscular biopsy is based on images of longitudinal sections of the fibers. Sometimes, due to experimental limitations, the resulting sections are instead oblique, and no accurate morphological information can be extracted with standard analysis methods. Thus, the biopsy is performed again, but this is too invasive and time-consuming. In this study, we focused our attention on the sarcomere's shape and we investigated which is the structural information that can be obtained from oblique sections. A routine was written in MATLAB to allow the visualization of how a sarcomere's section appears in ultrastructural images obtained by Transmission Electron Microscopy (TEM) at different secant angles. The routine was used also to analyze the intersection between a cylinder and a plane to show how the Z-bands and M-line lengths vary at different secant angles. Moreover, we explored how to calculate sarcomere's radius and length as well as the secant angle from ultrastructural images, based only on geometrical considerations (Pythagorean theorem and trigonometric functions). The equations to calculate these parameters starting from ultrastructural image measurements were found. Noteworthy, to obtain the real sarcomere length in quasi-longitudinal sections, a small correction in the standard procedure is needed and highlighted in the text. In conclusion, even non-longitudinal sections of skeletal muscles can be used to extrapolate morphological information of sarcomeres, which are important parameters for diagnostic purposes.
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Affiliation(s)
- Federico Boschi
- Department of Engineering of Innovation MedicineUniversity of VeronaVeronaItaly
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Rozen EJ, Ozeroff CD, Allen MA. RUN(X) out of blood: emerging RUNX1 functions beyond hematopoiesis and links to Down syndrome. Hum Genomics 2023; 17:83. [PMID: 37670378 PMCID: PMC10481493 DOI: 10.1186/s40246-023-00531-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 08/29/2023] [Indexed: 09/07/2023] Open
Abstract
BACKGROUND RUNX1 is a transcription factor and a master regulator for the specification of the hematopoietic lineage during embryogenesis and postnatal megakaryopoiesis. Mutations and rearrangements on RUNX1 are key drivers of hematological malignancies. In humans, this gene is localized to the 'Down syndrome critical region' of chromosome 21, triplication of which is necessary and sufficient for most phenotypes that characterize Trisomy 21. MAIN BODY Individuals with Down syndrome show a higher predisposition to leukemias. Hence, RUNX1 overexpression was initially proposed as a critical player on Down syndrome-associated leukemogenesis. Less is known about the functions of RUNX1 in other tissues and organs, although growing reports show important implications in development or homeostasis of neural tissues, muscle, heart, bone, ovary, or the endothelium, among others. Even less is understood about the consequences on these tissues of RUNX1 gene dosage alterations in the context of Down syndrome. In this review, we summarize the current knowledge on RUNX1 activities outside blood/leukemia, while suggesting for the first time their potential relation to specific Trisomy 21 co-occurring conditions. CONCLUSION Our concise review on the emerging RUNX1 roles in different tissues outside the hematopoietic context provides a number of well-funded hypotheses that will open new research avenues toward a better understanding of RUNX1-mediated transcription in health and disease, contributing to novel potential diagnostic and therapeutic strategies for Down syndrome-associated conditions.
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Affiliation(s)
- Esteban J Rozen
- Crnic Institute Boulder Branch, BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave., Boulder, CO, 80303, USA.
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, 12700 East 19th Avenue, Aurora, CO, 80045, USA.
| | - Christopher D Ozeroff
- Crnic Institute Boulder Branch, BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave., Boulder, CO, 80303, USA
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, 12700 East 19th Avenue, Aurora, CO, 80045, USA
- Department of Molecular, Cellular and Developmental Biology, University of Colorado Boulder, 1945 Colorado Ave., Boulder, CO, 80309, USA
| | - Mary Ann Allen
- Crnic Institute Boulder Branch, BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave., Boulder, CO, 80303, USA.
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, 12700 East 19th Avenue, Aurora, CO, 80045, USA.
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Inguscio CR, Lacavalla MA, Cisterna B, Zancanaro C, Malatesta M. Physical Training Chronically Stimulates the Motor Neuron Cell Nucleus in the Ts65Dn Mouse, a Model of Down Syndrome. Cells 2023; 12:1488. [PMID: 37296609 PMCID: PMC10252427 DOI: 10.3390/cells12111488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 05/20/2023] [Accepted: 05/24/2023] [Indexed: 06/12/2023] Open
Abstract
Down syndrome (DS) is a genetically-based disease based on the trisomy of chromosome 21 (Hsa21). DS is characterized by intellectual disability in association with several pathological traits among which early aging and altered motor coordination are prominent. Physical training or passive exercise were found to be useful in counteracting motor impairment in DS subjects. In this study we used the Ts65Dn mouse, a widely accepted animal model of DS, to investigate the ultrastructural architecture of the medullary motor neuron cell nucleus taken as marker of the cell functional state. Using transmission electron microscopy, ultrastructural morphometry, and immunocytochemistry we carried out a detailed investigation of possible trisomy-related alteration(s) of nuclear constituents, which are known to vary their amount and distribution as a function of nuclear activity, as well as the effect of adapted physical training upon them. Results demonstrated that trisomy per se affects nuclear constituents to a limited extent; however, adapted physical training is able to chronically stimulate pre-mRNA transcription and processing activity in motor neuron nuclei of trisomic mice, although to a lesser extent than in their euploid mates. These findings are a step towards understanding the mechanisms underlying the positive effect of physical activity in DS.
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Affiliation(s)
| | | | | | - Carlo Zancanaro
- Department of Neurosciences, Biomedicine and Movement Sciences, Anatomy and Histology Section, University of Verona, Strada Le Grazie 8, I-37134 Verona, Italy; (C.R.I.); (M.A.L.); (B.C.); (M.M.)
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7
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Melo GLR, Moraes MR, Nascimento EF, Boato EM, Beal FLR, Stone W, da Cunha Nascimento D. Field-based versus laboratory-based estimates of muscle quality index in adolescents with and without Down syndrome. JOURNAL OF INTELLECTUAL DISABILITY RESEARCH : JIDR 2022; 66:1000-1008. [PMID: 35734961 DOI: 10.1111/jir.12959] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 06/06/2022] [Accepted: 06/08/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Low muscle quality index (MQI) is a potential risk of developing functional impairments in older people. However, considering that individuals with Down syndrome (DS) present with a faster decline in biological aging, an investigation on MQI in individuals with DS is necessary. The aims of this present cross-sectional study were to compare (1) MQI between adolescents with and without DS and (2) evaluate laboratory versus field-based estimates of MQI. METHODS Fifty-six adolescents were recruited and separated into two groups: DS (n = 30, 13 boys and 17 girls; age: 12.38 ± 3.07 years) and a control (non-DS; n = 26, 9 boys and 17 girls; age: 12.46 ± 2.88 years). Laboratory MQI was derived from the ratio of grip strength to arm muscle mass (in kg) measured by dual-energy X-ray absorptiometry (DXA). Field-based MQI was quantified from the ratio of hand grip strength (HGS) to body mass index (BMI). For statistical analyses, a two-way ANOVA was conducted for group comparisons, and a Pearson correlation was used to test the association between field MQI and laboratory MQI. RESULTS Adolescents with DS displayed lower field (P = 0.001), laboratory MQI estimates (P = 0.001) and HGS (P = 0.001) as compared non-DS. Also, there was a strong correlation effect between field MQI and laboratory MQI estimates (P < 0.001, R = 0.81). CONCLUSION Adolescents with DS have lower field and laboratory MQI compared with adolescents without DS. Simpler field MQI might be used in daily clinical practice, with special attention to those with DS.
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Affiliation(s)
- G L R Melo
- Department of Physical Education, Catholic University of Brasília, Brasília, Brazil
| | - M R Moraes
- Department of Physical Education, Catholic University of Brasília, Brasília, Brazil
| | - E F Nascimento
- Department of Physical Education, Catholic University of Brasília, Brasília, Brazil
- Department of Physical Education, Secretary of the State of Education of the Federal District, Brasília, Brazil
| | - E M Boato
- Department of Physical Education, Secretary of the State of Education of the Federal District, Brasília, Brazil
| | - F L R Beal
- Department of Gerontology, Catholic University of Brasília, Brasília, Brazil
| | - W Stone
- Department of School of Kinesiology Recreation and Sport, Western Kentucky University, Bowling Green, FL, USA
| | - D da Cunha Nascimento
- Department of Physical Education, Catholic University of Brasília, Brasília, Brazil
- Department of Gerontology, Catholic University of Brasília, Brasília, Brazil
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8
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Cisterna B, Malatesta M, Zancanaro C, Boschi F. A computational approach to quantitatively define sarcomere dimensions and arrangement in skeletal muscle. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2021; 211:106437. [PMID: 34624632 DOI: 10.1016/j.cmpb.2021.106437] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 09/18/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND AND OBJECTIVE The skeletal muscle is composed of integrated tissues mainly composed of myofibers i.e., long, cylindrical syncytia, whose cytoplasm is mostly occupied by parallel myofibrils. In section, each myofibril is organized in serially end-to-end arranged sarcomeres connected by Z lines. In muscle disorders, these structural and functional units can undergo structural alterations in terms of Z-line and sarcomere lengths, as well as lateral alignment of Z-line among adjacent myofibrils. In this view, objectifying alterations of the myofibril and sarcomere architecture would provide a solid foundation for qualitative observations. In this work, specific quantitative parameters characterizing the sarcomere and myofibril arrangement were defined using a computerized analysis of ultrastructural images. METHODS computerized analysis was carried out on transmission electron microscopy pictures of the murine vastus lateralis muscle. Samples from both euploid (control) and trisomic (showing myofiber alterations) Ts65Dn mice were used. Two routines were written in MATLAB to measure specific structural parameters on sarcomeres and myofibrils. The output included the Z-line, M-line, and sarcomere lengths, the Aspect Ratio (AsR) and Curviness (Cur) sarcomere shape parameters, myofibril axis (α angle), and the H parameter (evaluation of sequence of Z-lines of adjacent myofibrils). RESULTS Both routines worked well in control (euploid) skeletal muscle yielding consistent quantitative data of sarcomere and myofibril structural organization. In comparison with euploid, trisomic muscle showed statistically significant lower Z-line length, similar M-line length, and statistically significant lower sarcomere length. Both AsR and Cur were statistically significantly lower in trisomic muscle, suggesting the sarcomere is barrel-shaped in the latter. The angle (α) distribution showed that the sarcomere axes are almost parallel in euploid muscle, while a large variability occurs in trisomic tissue. The mean value of H was significantly higher in trisomic versus euploid muscle indicating that Z-lines are not perfectly aligned in trisomic muscle. CONCLUSIONS Our procedure allowed us to accurately extract and quantify sarcomere and myofibril parameters from the high-resolution electron micrographs thereby yielding an effective tool to quantitatively define trisomy-associated muscle alterations. These results pave the way to future objective quantification of skeletal muscle changes in pathological conditions. SHORT ABSTRACT The skeletal muscle is composed of integrated tissues mainly composed of myofibers i.e., long, cylindrical syncytia, whose cytoplasm is mostly occupied by parallel myofibrils organized in serially end-to-end arranged sarcomeres. Several pieces of evidence have highlighted that in muscle disorders and diseases the sarcomere structure may be altered. Therefore, objectifying alterations of the myofibril and sarcomere architecture would provide a solid foundation for qualitative observations. A computerized analysis was carried out on transmission electron microscopy images of euploid (control) and trisomic (showing myofiber alterations) skeletal muscle. Two routines were written in MATLAB to measure nine sarcomere and myofibril structural parameters. Our computational method confirmed and expanded on previous qualitative ultrastructural findings defining several trisomy-associated skeletal muscle alterations. The proposed procedure is a potentially useful tool to quantitatively define skeletal muscle changes in pathological conditions involving the sarcomere.
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Affiliation(s)
- Barbara Cisterna
- Anatomy and Histology Section, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Strada Le Grazie 8, Verona 37134, Italy
| | - Manuela Malatesta
- Anatomy and Histology Section, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Strada Le Grazie 8, Verona 37134, Italy
| | - Carlo Zancanaro
- Anatomy and Histology Section, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Strada Le Grazie 8, Verona 37134, Italy
| | - Federico Boschi
- Department of Computer Science, University of Verona, Strada Le Grazie 15, Verona 37134, Italy.
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Alldred MJ, Lee SH, Stutzmann GE, Ginsberg SD. Oxidative Phosphorylation Is Dysregulated Within the Basocortical Circuit in a 6-month old Mouse Model of Down Syndrome and Alzheimer's Disease. Front Aging Neurosci 2021; 13:707950. [PMID: 34489678 PMCID: PMC8417045 DOI: 10.3389/fnagi.2021.707950] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 07/13/2021] [Indexed: 01/14/2023] Open
Abstract
Down syndrome (DS) is the primary genetic cause of intellectual disability (ID), which is due to the triplication of human chromosome 21 (HSA21). In addition to ID, HSA21 trisomy results in a number of neurological and physiological pathologies in individuals with DS, including progressive cognitive dysfunction and learning and memory deficits which worsen with age. Further exacerbating neurological dysfunction associated with DS is the concomitant basal forebrain cholinergic neuron (BFCN) degeneration and onset of Alzheimer's disease (AD) pathology in early mid-life. Recent single population RNA sequencing (RNA-seq) analysis in the Ts65Dn mouse model of DS, specifically the medial septal cholinergic neurons of the basal forebrain (BF), revealed the mitochondrial oxidative phosphorylation pathway was significantly impacted, with a large subset of genes within this pathway being downregulated. We further queried oxidative phosphorylation pathway dysregulation in Ts65Dn mice by examining genes and encoded proteins within brain regions comprising the basocortical system at the start of BFCN degeneration (6 months of age). In select Ts65Dn mice we demonstrate significant deficits in gene and/or encoded protein levels of Complex I-V of the mitochondrial oxidative phosphorylation pathway in the BF. In the frontal cortex (Fr Ctx) these complexes had concomitant alterations in select gene expression but not of the proteins queried from Complex I-V, suggesting that defects at this time point in the BF are more severe and occur prior to cortical dysfunction within the basocortical circuit. We propose dysregulation within mitochondrial oxidative phosphorylation complexes is an early marker of cognitive decline onset and specifically linked to BFCN degeneration that may propagate pathology throughout cortical memory and executive function circuits in DS and AD.
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Affiliation(s)
- Melissa J Alldred
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY, United States.,Departments of Psychiatry, New York University Grossman School of Medicine, New York, NY, United States
| | - Sang Han Lee
- Center for Biomedical Imaging and Neuromodulation, Nathan Kline Institute, Orangeburg, NY, United States.,Department of Child and Adolescent Psychiatry, New York University Grossman School of Medicine, New York, NY, United States
| | - Grace E Stutzmann
- Center for Neurodegenerative Disease and Therapeutics, Discipline of Neuroscience, Rosalind Franklin University/The Chicago Medical School, North Chicago, IL, United States
| | - Stephen D Ginsberg
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY, United States.,Departments of Psychiatry, New York University Grossman School of Medicine, New York, NY, United States.,Neuroscience & Physiology, New York University Grossman School of Medicine, New York, NY, United States.,NYU Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, United States
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