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Schultheis N, Connell A, Kapral A, Becker RJ, Mueller R, Shah S, O'Donnell M, Roseman M, Swanson L, DeGuara S, Wang W, Yin F, Saini T, Weiss RJ, Selleck SB. Altering heparan sulfate suppresses cell abnormalities and neuron loss in Drosophila presenilin model of Alzheimer Disease. iScience 2024; 27:110256. [PMID: 39109174 PMCID: PMC11302002 DOI: 10.1016/j.isci.2024.110256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 05/06/2024] [Accepted: 06/10/2024] [Indexed: 08/10/2024] Open
Abstract
We examined the function of heparan-sulfate-modified proteoglycans (HSPGs) in pathways affecting Alzheimer disease (AD)-related cell pathology in human cell lines and mouse astrocytes. Mechanisms of HSPG influences on presenilin-dependent cell loss were evaluated in Drosophila using knockdown of the presenilin homolog, Psn, together with partial loss-of-function of sulfateless (sfl), a gene specifically affecting HS sulfation. HSPG modulation of autophagy, mitochondrial function, and lipid metabolism were shown to be conserved in human cell lines, Drosophila, and mouse astrocytes. RNA interference (RNAi) of Ndst1 reduced intracellular lipid levels in wild-type mouse astrocytes or those expressing humanized variants of APOE, APOE3, and APOE4. Neuron-directed knockdown of Psn in Drosophila produced apoptosis and cell loss in the brain, phenotypes suppressed by reductions in sfl expression. Abnormalities in mitochondria, liposomes, and autophagosome-derived structures in animals with Psn knockdown were also rescued by reduction of sfl. These findings support the direct involvement of HSPGs in AD pathogenesis.
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Affiliation(s)
- Nicholas Schultheis
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Alyssa Connell
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Alexander Kapral
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Robert J. Becker
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Richard Mueller
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Shalini Shah
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Mackenzie O'Donnell
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Matthew Roseman
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Lindsey Swanson
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Sophia DeGuara
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Weihua Wang
- Center for Innovation in Brain Science and Department of Pharmacology, University of Arizona, Tucson, AZ 85721, USA
| | - Fei Yin
- Center for Innovation in Brain Science and Department of Pharmacology, University of Arizona, Tucson, AZ 85721, USA
| | - Tripti Saini
- Department of Biochemistry and Molecular Biology, Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - Ryan J. Weiss
- Department of Biochemistry and Molecular Biology, Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - Scott B. Selleck
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
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Schultheis N, Connell A, Kapral A, Becker RJ, Mueller R, Shah S, O'Donnell M, Roseman M, Wang W, Yin F, Weiss R, Selleck SB. Heparan sulfate modified proteins affect cellular processes central to neurodegeneration and modulate presenilin function. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.23.576895. [PMID: 38328107 PMCID: PMC10849577 DOI: 10.1101/2024.01.23.576895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Mutations in presenilin-1 (PSEN1) are the most common cause of familial, early-onset Alzheimer's disease (AD), typically producing cognitive deficits in the fourth decade. A variant of APOE, APOE3 Christchurch (APOE3ch) , was found associated with protection from both cognitive decline and Tau accumulation in a 70-year-old bearing the disease-causing PSEN1-E280A mutation. The amino acid change in ApoE3ch is within the heparan sulfate (HS) binding domain of APOE, and purified APOEch showed dramatically reduced affinity for heparin, a highly sulfated form of HS. The physiological significance of ApoE3ch is supported by studies of a mouse bearing a knock-in of this human variant and its effects on microglia reactivity and Aβ-induced Tau deposition. The studies reported here examine the function of heparan sulfate-modified proteoglycans (HSPGs) in cellular and molecular pathways affecting AD-related cell pathology in human cell lines and mouse astrocytes. The mechanisms of HSPG influences on presenilin- dependent cell loss and pathology were evaluated in Drosophila using knockdown of the presenilin homolog, Psn , together with partial loss of function of sulfateless (sfl) , a homolog of NDST1 , a gene specifically affecting HS sulfation. HSPG modulation of autophagy, mitochondrial function, and lipid metabolism were shown to be conserved in cultured human cell lines, Drosophila , and mouse astrocytes. RNAi of Ndst1 reduced intracellular lipid levels in wild-type mouse astrocytes or those expressing humanized variants of APOE, APOE3 , and APOE4 . RNA-sequence analysis of human cells deficient in HS synthesis demonstrated effects on the transcriptome governing lipid metabolism, autophagy, and mitochondrial biogenesis and showed significant enrichment in AD susceptibility genes identified by GWAS. Neuron-directed knockdown of Psn in Drosophila produced cell loss in the brain and behavioral phenotypes, both suppressed by simultaneous reductions in sfl mRNA levels. Abnormalities in mitochondria, liposome morphology, and autophagosome-derived structures in animals with Psn knockdown were also rescued by simultaneous reduction of sfl. sfl knockdown reversed Psn- dependent transcript changes in genes affecting lipid transport, metabolism, and monocarboxylate carriers. These findings support the direct involvement of HSPGs in AD pathogenesis.
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