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Carman BL, Qin S, Predescu DN, Jana M, Cortese R, Aldred MA, Gozal D, Mokhlesi B, Predescu SA. Dysregulation of the Long Non-coding RNA Xist Expression in Male Patients with Pulmonary Arterial Hypertension. Am J Pathol 2024:S0002-9440(24)00166-4. [PMID: 38705381 DOI: 10.1016/j.ajpath.2024.04.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 03/10/2024] [Accepted: 04/09/2024] [Indexed: 05/07/2024]
Abstract
Pulmonary arterial hypertension (PAH) is a sex-biased disease with female gender as a significant risk factor. Recently, we reported that increased expression of the long non-coding (lnc)RNA Xist, as induced by an intersectin-1s protein fragment with proliferative potential (EHITSN), may explain the sexual dimorphism of female pulmonary artery endothelial cells (ECs) and at least in part, the imbalance sex/ratio of PAH. Xist is essential for X-chromosome inactivation and dosage compensation of X-linked genes. Increased Xist expression was also detected in a subset of ECs and lung tissue samples of male PAH patients. The role of different Xist expression levels in ECs of male PAH patients (ECPAH) was studied in several lines of male ECPAH in conjunction with molecular, biochemical, morphological, and functional approaches. Male ECPAH showed on average 10.3-fold increase in high Xist vs. low Xist, a significant association between Xist levels and their proliferative potential, and a heterogeneous methylation of the Xist/Tsix locus. Interestingly, Xist up-regulation in male ECPAH decreases the expression of Klf2, via EHITSN interaction with EZH2, the catalytic subunit of the polycomb repressive complex 2. Moreover, the studies demonstrate that EHITSN-triggered p38/Elk1/c-Fos signaling is a pathological mechanism central to ECPAH proliferation and the dynamic crosstalk with cell cycle regulatory proteins ccna1/ccnd2, and Xist-EZH2-Klf2 interaction participate directly and differentially in establishing the proliferative profile of male ECPAH.
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Affiliation(s)
- Brandon L Carman
- Division of Pulmonary, Critical Care and Sleep Medicine, Rush University Medical Center, Chicago, IL
| | - Shanshan Qin
- Division of Pulmonary, Critical Care and Sleep Medicine, Rush University Medical Center, Chicago, IL
| | - Dan N Predescu
- Division of Pulmonary, Critical Care and Sleep Medicine, Rush University Medical Center, Chicago, IL
| | - Malabendu Jana
- Department of Neurological Science, Rush University Medical Center
| | - Rene Cortese
- Child Health Research Institute, University of Missouri, Colombia, MO
| | - Micheala A Aldred
- Division of Pulmonary, Critical Care, Sleep and Occupational Medicine, Indiana University School of Medicine, Indianapolis, IN
| | - David Gozal
- Joan C, Edwards School of Medicine, Marshall University, Huntington, WV
| | - Babak Mokhlesi
- Division of Pulmonary, Critical Care and Sleep Medicine, Rush University Medical Center, Chicago, IL
| | - Sanda A Predescu
- Division of Pulmonary, Critical Care and Sleep Medicine, Rush University Medical Center, Chicago, IL.
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Ivraghi MS, Zamanian MY, Gupta R, Achmad H, Alsaab HO, Hjazi A, Romero‐Parra RM, Alwaily ER, Hussien BM, Hakimizadeh E. Neuroprotective effects of gemfibrozil in neurological disorders: Focus on inflammation and molecular mechanisms. CNS Neurosci Ther 2024; 30:e14473. [PMID: 37904726 PMCID: PMC10916451 DOI: 10.1111/cns.14473] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 08/15/2023] [Accepted: 09/03/2023] [Indexed: 11/01/2023] Open
Abstract
BACKGROUND Gemfibrozil (Gem) is a drug that has been shown to activate PPAR-α, a nuclear receptor that plays a key role in regulating lipid metabolism. Gem is used to lower the levels of triglycerides and reduce the risk of coronary heart disease in patients. Experimental studies in vitro and in vivo have shown that Gem can prevent or slow the progression of neurological disorders (NDs), including cerebral ischemia (CI), Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis (MS). Neuroinflammation is known to play a significant role in these disorders. METHOD The literature review for this study was conducted by searching Scopus, Science Direct, PubMed, and Google Scholar databases. RESULT The results of this study show that Gem has neuroprotective effects through several cellular and molecular mechanisms such as: (1) Gem has the ability to upregulate pro-survival factors (PGC-1α and TFAM), promoting the survival and function of mitochondria in the brain, (2) Gem strongly inhibits the activation of NF-κB, AP-1, and C/EBPβ in cytokine-stimulated astroglial cells, which are known to increase the expression of iNOS and the production of NO in response to proinflammatory cytokines, (3) Gem protects dopamine neurons in the MPTP mouse model of PD by increasing the expression of PPARα, which in turn stimulates the production of GDNF in astrocytes, (4) Gem reduces amyloid plaque pathology, reduces the activity of glial cells, and improves memory, (5) Gem increases myelin genes expression (MBP and CNPase) via PPAR-β, and (6) Gem increases hippocampal BDNF to counteract depression. CONCLUSION According to the study, Gem was investigated for its potential therapeutic effect in NDs. Further research is needed to fully understand the therapeutic potential of Gem in NDs.
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Affiliation(s)
| | - Mohammad Yasin Zamanian
- Neurophysiology Research CenterHamadan University of Medical SciencesHamadanIran
- Department of Pharmacology and Toxicology, School of PharmacyHamadan University of Medical SciencesHamadanIran
| | - Reena Gupta
- Institute of Pharmaceutical Research, GLA UniversityMathuraIndia
| | - Harun Achmad
- Department of Pediatric Dentistry, Faculty of DentistryHasanuddin UniversityMakassarIndonesia
| | - Hashem O. Alsaab
- Pharmaceutics and Pharmaceutical TechnologyTaif UniversityTaifSaudi Arabia
| | - Ahmed Hjazi
- Department of Medical Laboratory SciencesCollege of Applied Medical Sciences, Prince Sattam bin Abdulaziz UniversityAl‐KharjSaudi Arabia
| | | | - Enas R. Alwaily
- Microbiology Research GroupCollege of Pharmacy, Al‐Ayen UniversityThi‐QarIraq
| | - Beneen M. Hussien
- Medical Laboratory Technology DepartmentCollege of Medical Technology, The Islamic UniversityNajafIraq
| | - Elham Hakimizadeh
- Physiology‐Pharmacology Research CenterResearch Institute of Basic Medical Sciences, Rafsanjan University of Medical SciencesRafsanjanIran
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Raha S, Paidi RK, Dutta D, Pahan K. Cinnamic acid, a natural plant compound, exhibits neuroprotection in a mouse model of Sandhoff disease via PPARα. NeuroImmune Pharm Ther 2024; 3:17-32. [PMID: 38532783 PMCID: PMC10961485 DOI: 10.1515/nipt-2023-0027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Accepted: 02/26/2024] [Indexed: 03/28/2024]
Abstract
Tay-Sachs disease (TSD) and its severe form Sandhoff disease (SD) are autosomal recessive lysosomal storage metabolic disorders, which often result into excessive GM2 ganglioside accumulation predominantly in lysosomes of nerve cells. Although patients with these diseases appear normal at birth, the progressive accumulation of undegraded GM2 gangliosides in neurons leads to early death accompanied by manifestation of motor difficulties and gradual loss of behavioral skills. Unfortunately, there is still no effective treatment available for TSD/SD. The present study highlights the importance of cinnamic acid (CA), a naturally occurring aromatic fatty acid present in a number of plants, in inhibiting the disease process in a transgenic mouse model of SD. Oral administration of CA significantly attenuated glial activation and inflammation and reduced the accumulation of GM2 gangliosides/glycoconjugates in the cerebral cortex of Sandhoff mice. Besides, oral CA also improved behavioral performance and increased the survival of Sandhoff mice. While assessing the mechanism, we found that oral administration of CA increased the level of peroxisome proliferator-activated receptor α (PPARα) in the brain of Sandhoff mice and that oral CA remained unable to reduce glycoconjugates, improve behavior and increase survival in Sandhoff mice lacking PPARα. Our results indicate a beneficial function of CA that utilizes a PPARα-dependent mechanism to halt the progression of SD and thereby increase the longevity of Sandhoff mice.
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Affiliation(s)
- Sumita Raha
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA
| | - Ramesh K Paidi
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA
| | - Debashis Dutta
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA
| | - Kalipada Pahan
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA
- Division of Research and Development, Jesse Brown Veterans Affairs Medical Center, Chicago, IL, USA
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Jana M, Prieto S, Gorai S, Dasarathy S, Kundu M, Pahan K. Muscle-building supplement β-hydroxy β-methylbutyrate stimulates the maturation of oligodendroglial progenitor cells to oligodendrocytes. J Neurochem 2024. [PMID: 38419348 DOI: 10.1111/jnc.16084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 01/10/2024] [Accepted: 02/06/2024] [Indexed: 03/02/2024]
Abstract
Oligodendrocytes are the myelinating cells in the CNS and multiple sclerosis (MS) is a demyelinating disorder that is characterized by progressive loss of myelin. Although oligodendroglial progenitor cells (OPCs) should be differentiated into oligodendrocytes, for multiple reasons, OPCs fail to differentiate into oligodendrocytes in MS. Therefore, increasing the maturation of OPCs to oligodendrocytes may be of therapeutic benefit for MS. The β-hydroxy β-methylbutyrate (HMB) is a muscle-building supplement in humans and this study underlines the importance of HMB in stimulating the maturation of OPCs to oligodendrocytes. HMB treatment upregulated the expression of different maturation markers including PLP, MBP, and MOG in cultured OPCs. Double-label immunofluorescence followed by immunoblot analyses confirmed the upregulation of OPC maturation by HMB. While investigating mechanisms, we found that HMB increased the maturation of OPCs isolated from peroxisome proliferator-activated receptor β-/- (PPARβ-/- ) mice, but not PPARα-/- mice. Similarly, GW6471 (an antagonist of PPARα), but not GSK0660 (an antagonist of PPARβ), inhibited HMB-induced maturation of OPCs. GW9662, a specific inhibitor of PPARγ, also could not inhibit HMB-mediated stimulation of OPC maturation. Furthermore, PPARα agonist GW7647, but neither PPARβ agonist GW0742 nor PPARγ agonist GW1929, alone increased the maturation of OPCs. Finally, HMB treatment of OPCs led to the recruitment of PPARα, but neither PPARβ nor PPARγ, to the PLP gene promoter. These results suggest that HMB stimulates the maturation of OPCs via PPARα and that HMB may have therapeutic prospects in remyelination.
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Affiliation(s)
- Malabendu Jana
- Department of Neurological Sciences, Rush University Medical Center, Chicago, Illinois, USA
- Division of Research and Development, Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois, USA
| | - Shelby Prieto
- Department of Neurological Sciences, Rush University Medical Center, Chicago, Illinois, USA
| | - Sukhamoy Gorai
- Department of Neurological Sciences, Rush University Medical Center, Chicago, Illinois, USA
| | - Sridevi Dasarathy
- Department of Neurological Sciences, Rush University Medical Center, Chicago, Illinois, USA
| | - Madhuchhanda Kundu
- Department of Neurological Sciences, Rush University Medical Center, Chicago, Illinois, USA
| | - Kalipada Pahan
- Department of Neurological Sciences, Rush University Medical Center, Chicago, Illinois, USA
- Division of Research and Development, Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois, USA
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Gonzalez-Rodriguez M, Marin-Valencia I. Metabolic Determinants of Cerebellar Circuit Formation and Maintenance. Cerebellum 2023:10.1007/s12311-023-01641-2. [PMID: 38123901 DOI: 10.1007/s12311-023-01641-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/27/2023] [Indexed: 12/23/2023]
Abstract
Cells configure their metabolism in a synchronized and timely manner to meet their energy demands throughout development and adulthood. Transitions of developmental stages are coupled to metabolic shifts, such that glycolysis is highly active during cell proliferation, whereas oxidative phosphorylation prevails in postmitotic states. In the cerebellum, metabolic transitions are remarkable given its protracted developmental timelines. Such distinctive feature, along with its high neuronal density and metabolic demands, make the cerebellum highly vulnerable to metabolic insults. Despite the expansion of metabolomic approaches to uncover biological mechanisms, little is known about the role of metabolism on cerebellar development and maintenance. To illuminate the intricate connections between metabolism, physiology, and cerebellar disorders, we examined here the impact of metabolism on cerebellar growth, maturation, and adulthood through the lens of inborn errors of metabolism.
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Affiliation(s)
- Manuel Gonzalez-Rodriguez
- The Abimael Laboratory of Neurometabolism, Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Isaac Marin-Valencia
- The Abimael Laboratory of Neurometabolism, Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
- Departments of Neuroscience, Genetics and Genomics Medicine, and Pediatrics Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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Centa JL, Stratton MP, Pratt MA, Osterlund Oltmanns JR, Wallace DG, Miller SA, Weimer JM, Hastings ML. Protracted CLN3 Batten disease in mice that genetically model an exon-skipping therapeutic approach. Mol Ther Nucleic Acids 2023; 33:15-27. [PMID: 37359347 PMCID: PMC10285469 DOI: 10.1016/j.omtn.2023.05.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 05/31/2023] [Indexed: 06/28/2023]
Abstract
Genetic mutations that disrupt open reading frames and cause translation termination are frequent causes of human disease and are difficult to treat due to protein truncation and mRNA degradation by nonsense-mediated decay, leaving few options for traditional drug targeting. Splice-switching antisense oligonucleotides offer a potential therapeutic solution for diseases caused by disrupted open reading frames by inducing exon skipping to correct the open reading frame. We have recently reported on an exon-skipping antisense oligonucleotide that has a therapeutic effect in a mouse model of CLN3 Batten disease, a fatal pediatric lysosomal storage disease. To validate this therapeutic approach, we generated a mouse model that constitutively expresses the Cln3 spliced isoform induced by the antisense molecule. Behavioral and pathological analyses of these mice demonstrate a less severe phenotype compared with the CLN3 disease mouse model, providing evidence that antisense oligonucleotide-induced exon skipping can have therapeutic efficacy in treating CLN3 Batten disease. This model highlights how protein engineering through RNA splicing modulation can be an effective therapeutic approach.
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Affiliation(s)
- Jessica L. Centa
- Center for Genetic Diseases, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
| | - Matthew P. Stratton
- Center for Genetic Diseases, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
- School of Graduate and Postdoctoral Studies, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
| | - Melissa A. Pratt
- Pediatrics and Rare Diseases Group, Sanford Research, Sioux Falls, SD 57104, USA
| | | | - Douglas G. Wallace
- Department of Psychology, Northern Illinois University, DeKalb, IL 60115, USA
| | - Steven A. Miller
- Psychology Department, College of Health Professionals, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
| | - Jill M. Weimer
- Pediatrics and Rare Diseases Group, Sanford Research, Sioux Falls, SD 57104, USA
- Department of Pediatrics, Sanford School of Medicine, University of South Dakota, Sioux Falls, SD 57104, USA
| | - Michelle L. Hastings
- Center for Genetic Diseases, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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Chakrabarti S, Gorai S, Pahan K. A simple protocol for isolating microglia from adult mouse brain. NeuroImmune Pharm Ther 2023; 2:293-300. [PMID: 37885917 PMCID: PMC10474378 DOI: 10.1515/nipt-2023-0014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Accepted: 07/20/2023] [Indexed: 10/28/2023]
Abstract
Objectives Although microglia are activated in adult and aged brains resulting in neurodegenerative and neuroinflammatory disorders, most of the cell culture studies on microglia deal with neonatal microglia because of ease of isolation. Microglia could be isolated from adult brains, but it requires separation by density gradient centrifugation, magnetic beads, etc. Here, we describe a simple protocol of isolating highly purified microglia from adult mouse brains. Methods Our protocol involves dilution with sterile PBS or media, regular centrifugation, and plating on poly-D-lysine-coated flasks. Results These adult microglia expressed the inducible nitric oxide synthase in response to preformed α-syn fibril, an etiological reagent of Parkinson's disease, and bacterial lipopolysaccharides, one of the prototype proinflammatory stimuli. Moreover, these adult microglia exhibited phagocytosis, which was stimulated by LPS treatment. Conclusions These results suggest that adult microglia isolated by our procedure are functional and that these adult microglia could be used for studies related to neurodegenerative disorders.
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Affiliation(s)
- Sudipta Chakrabarti
- Department of Neurological Sciences, Rush University Medical Center, Chicago, USA
| | - Sukhamoy Gorai
- Department of Neurological Sciences, Rush University Medical Center, Chicago, USA
| | - Kalipada Pahan
- Department of Neurological Sciences, Rush University Medical Center, Chicago, USA
- Division of Research and Development, Jesse Brown Veterans Affairs Medical Center, Chicago, USA
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Zhang L, Li Z, Zhang L, Qin Y, Yu D. Dissecting the multifaced function of transcription factor EB (TFEB) in human diseases: From molecular mechanism to pharmacological modulation. Biochem Pharmacol 2023; 215:115698. [PMID: 37482200 DOI: 10.1016/j.bcp.2023.115698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 07/15/2023] [Accepted: 07/18/2023] [Indexed: 07/25/2023]
Abstract
The transcription factor EB (TFEB) is a transcription factor of the MiT/TFE family that translocations from the cytoplasm to the nucleus in response to various stimuli, including lysosomal stress and nutrient starvation. By activating genes involved in lysosomal function, autophagy, and lipid metabolism, TFEB plays a crucial role in maintaining cellular homeostasis. Dysregulation of TFEB has been implicated in various diseases, including cancer, neurodegenerative diseases, metabolic diseases, cardiovascular diseases, infectious diseases, and inflammatory diseases. Therefore, modulating TFEB activity with agonists or inhibitors may have therapeutic potential. In this review, we reviewed the recently discovered regulatory mechanisms of TFEB and their impact on human diseases. Additionally, we also summarize the existing TFEB inhibitors and agonists (targeted and non-targeted) and discuss unresolved issues and future research directions in the field. In summary, this review sheds light on the crucial role of TFEB, which may pave the way for its translation from basic research to practical applications, bringing us closer to realizing the full potential of TFEB in various fields.
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Affiliation(s)
- Lijuan Zhang
- Department of Pharmacy, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu 610072, China; Personalized Drug Therapy Key Laboratory of Sichuan Province, School of Medicine, University of Electronic Science and Technology of China, Chengdu 610072, China
| | - Zhijia Li
- Sichuan Engineering Research Center for Biomimetic Synthesis of Natural Drugs, School of Life Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China
| | - Lan Zhang
- Sichuan Engineering Research Center for Biomimetic Synthesis of Natural Drugs, School of Life Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China.
| | - Yuan Qin
- The Center of Gastrointestinal and Minimally Invasive Surgery, Department of General Surgery, The Third People's Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, Chengdu 610031, China; Medical Research Center, The Third People's Hospital of Chengdu, The Affiliated Hospital of Southwest Jiaotong University, Chengdu 610031, China.
| | - Dongke Yu
- Department of Pharmacy, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu 610072, China; Personalized Drug Therapy Key Laboratory of Sichuan Province, School of Medicine, University of Electronic Science and Technology of China, Chengdu 610072, China.
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Bullock G, Johnson GS, Pattridge SG, Mhlanga-Mutangadura T, Guo J, Cook J, Campbell RS, Vite CH, Katz ML. A Homozygous MAN2B1 Missense Mutation in a Doberman Pinscher Dog with Neurodegeneration, Cytoplasmic Vacuoles, Autofluorescent Storage Granules, and an α-Mannosidase Deficiency. Genes (Basel) 2023; 14:1746. [PMID: 37761886 PMCID: PMC10531151 DOI: 10.3390/genes14091746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 08/28/2023] [Accepted: 08/29/2023] [Indexed: 09/29/2023] Open
Abstract
A 7-month-old Doberman Pinscher dog presented with progressive neurological signs and brain atrophy suggestive of a hereditary neurodegenerative disorder. The dog was euthanized due to the progression of disease signs. Microscopic examination of tissues collected at the time of euthanasia revealed massive accumulations of vacuolar inclusions in cells throughout the central nervous system, suggestive of a lysosomal storage disorder. A whole genome sequence generated with DNA from the affected dog contained a likely causal, homozygous missense variant in MAN2B1 that predicted an Asp104Gly amino acid substitution that was unique among whole genome sequences from over 4000 dogs. A lack of detectable α-mannosidase enzyme activity confirmed a diagnosis of a-mannosidosis. In addition to the vacuolar inclusions characteristic of α-mannosidosis, the dog exhibited accumulations of autofluorescent intracellular inclusions in some of the same tissues. The autofluorescence was similar to that which occurs in a group of lysosomal storage disorders called neuronal ceroid lipofuscinoses (NCLs). As in many of the NCLs, some of the storage bodies immunostained strongly for mitochondrial ATP synthase subunit c protein. This protein is not a substrate for α-mannosidase, so its accumulation and the development of storage body autofluorescence were likely due to a generalized impairment of lysosomal function secondary to the accumulation of α-mannosidase substrates. Thus, it appears that storage body autofluorescence and subunit c accumulation are not unique to the NCLs. Consistent with generalized lysosomal impairment, the affected dog exhibited accumulations of intracellular inclusions with varied and complex ultrastructural features characteristic of autophagolysosomes. Impaired autophagic flux may be a general feature of this class of disorders that contributes to disease pathology and could be a target for therapeutic intervention. In addition to storage body accumulation, glial activation indicative of neuroinflammation was observed in the brain and spinal cord of the proband.
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Affiliation(s)
- Garrett Bullock
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA; (G.B.); (G.S.J.); (S.G.P.); (T.M.-M.); (J.G.)
| | - Gary S. Johnson
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA; (G.B.); (G.S.J.); (S.G.P.); (T.M.-M.); (J.G.)
| | - Savannah G. Pattridge
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA; (G.B.); (G.S.J.); (S.G.P.); (T.M.-M.); (J.G.)
| | - Tendai Mhlanga-Mutangadura
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA; (G.B.); (G.S.J.); (S.G.P.); (T.M.-M.); (J.G.)
| | - Juyuan Guo
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA; (G.B.); (G.S.J.); (S.G.P.); (T.M.-M.); (J.G.)
| | - James Cook
- Specialists in Companion Animal Neurology, Clearwater, FL 33765, USA;
| | - Rebecca S. Campbell
- Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (R.S.C.); (C.H.V.)
| | - Charles H. Vite
- Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (R.S.C.); (C.H.V.)
| | - Martin L. Katz
- Neurodegenerative Diseases Research Laboratory, Department of Ophthalmology, School of Medicine, University of Missouri, Columbia, MO 65212, USA
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