1
|
Seitzman GD, Keenan JD, Lietman TM, Ruder K, Zhong L, Chen C, Liu Y, Yu D, Abraham T, Hinterwirth A, Doan T. Human Conjunctival Transcriptome in Acanthamoeba Keratitis: An Exploratory Study. Cornea 2024; 43:1272-1277. [PMID: 38771726 PMCID: PMC11371541 DOI: 10.1097/ico.0000000000003545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 02/26/2024] [Indexed: 05/23/2024]
Abstract
PURPOSE The purpose of this study was to identify conjunctival transcriptome differences in patients with Acanthamoeba keratitis compared with keratitis with no known associated pathogen. METHODS The host conjunctival transcriptome of 9 patients with Acanthamoeba keratitis (AK) is compared with the host conjunctival transcriptome of 13 patients with pathogen-free keratitis. Culture and/or confocal confirmed Acanthamoeba in 8 of 9 participants with AK who underwent metagenomic RNA sequencing as the likely pathogen. Cultures were negative in all 13 cases where metagenomic RNA sequencing did not identify a pathogen. RESULTS Transcriptome analysis identified 36 genes differently expressed between patients with AK and patients with presumed sterile, or pathogen-free, keratitis. Gene enrichment analysis revealed that some of these genes participate in several biologic pathways important for cellular signaling, ion transport and homeostasis, glucose transport, and mitochondrial metabolism. Notable relatively differentially expressed genes with potential relevance to Acanthamoeba infection included CPS1 , SLC35B4 , STEAP2 , ATP2B2 , NMNAT3 , and AKAP12 . CONCLUSIONS This research suggests that the local transcriptome in Acanthamoeba keratitis may be sufficiently robust to be detected in the conjunctiva and that corneas infected with Acanthamoeba may be distinguished from the inflamed cornea where no pathogen was identified. Given the low sensitivity for corneal cultures, identification of differentially expressed genes may serve as a suggestive transcriptional signature allowing for a complementary diagnostic technique to identify this blinding parasite. Knowledge of differentially expressed genes may also direct investigation of disease pathophysiology and suggest novel pathways for therapeutic targets.
Collapse
Affiliation(s)
- Gerami D Seitzman
- Francis I. Proctor Foundation, University of California, San Francisco, California; and
- Department of Ophthalmology, University of California, San Francisco, California
| | - Jeremy D Keenan
- Francis I. Proctor Foundation, University of California, San Francisco, California; and
- Department of Ophthalmology, University of California, San Francisco, California
| | - Thomas M Lietman
- Francis I. Proctor Foundation, University of California, San Francisco, California; and
- Department of Ophthalmology, University of California, San Francisco, California
| | - Kevin Ruder
- Francis I. Proctor Foundation, University of California, San Francisco, California; and
| | - Lina Zhong
- Francis I. Proctor Foundation, University of California, San Francisco, California; and
| | - Cindi Chen
- Francis I. Proctor Foundation, University of California, San Francisco, California; and
| | - YuHeng Liu
- Francis I. Proctor Foundation, University of California, San Francisco, California; and
| | - Danny Yu
- Francis I. Proctor Foundation, University of California, San Francisco, California; and
| | - Thomas Abraham
- Francis I. Proctor Foundation, University of California, San Francisco, California; and
| | - Armin Hinterwirth
- Francis I. Proctor Foundation, University of California, San Francisco, California; and
| | - Thuy Doan
- Francis I. Proctor Foundation, University of California, San Francisco, California; and
- Department of Ophthalmology, University of California, San Francisco, California
| |
Collapse
|
2
|
Chandrasekaran K, Najimi N, Sagi AR, Yarlagadda S, Salimian M, Arvas MI, Hedayat AF, Kevas Y, Kadakia A, Kristian T, Russell JW. NAD + Precursors Reverse Experimental Diabetic Neuropathy in Mice. Int J Mol Sci 2024; 25:1102. [PMID: 38256175 PMCID: PMC10816262 DOI: 10.3390/ijms25021102] [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: 11/16/2023] [Revised: 01/05/2024] [Accepted: 01/13/2024] [Indexed: 01/24/2024] Open
Abstract
Abnormal NAD+ signaling has been implicated in axonal degeneration in diabetic peripheral neuropathy (DPN). We hypothesized that supplementing NAD+ precursors could alleviate DPN symptoms through increasing the NAD+ levels and activating the sirtuin-1 (SIRT1) protein. To test this, we exposed cultured Dorsal Root Ganglion neurons (DRGs) to Nicotinamide Riboside (NR) or Nicotinamide Mononucleotide (NMN), which increased the levels of NAD+, the SIRT1 protein, and the deacetylation activity that is associated with increased neurite growth. A SIRT1 inhibitor blocked the neurite growth induced via NR or NMN. We then induced neuropathy in C57BL6 mice with streptozotocin (STZ) or a high fat diet (HFD) and administered NR or NMN for two months. Both the STZ and HFD mice developed neuropathy, which was reversed through the NR or NMN administration: sensory function improved, nerve conduction velocities normalized, and intraepidermal nerve fibers were restored. The NAD+ levels and SIRT1 activity were reduced in the DRGs from diabetic mice but were preserved with the NR or NMN treatment. We also tested the effect of NR or NMN administration in mice that overexpress the SIRT1 protein in neurons (nSIRT1 OE) and found no additional benefit from the addition of the drug. These findings suggest that supplementing with NAD+ precursors or activating SIRT1 may be a promising treatment for DPN.
Collapse
Affiliation(s)
- Krish Chandrasekaran
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (K.C.); (N.N.); (S.Y.); (M.I.A.); (A.F.H.); (Y.K.); (A.K.)
| | - Neda Najimi
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (K.C.); (N.N.); (S.Y.); (M.I.A.); (A.F.H.); (Y.K.); (A.K.)
| | - Avinash R. Sagi
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (K.C.); (N.N.); (S.Y.); (M.I.A.); (A.F.H.); (Y.K.); (A.K.)
| | - Sushuma Yarlagadda
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (K.C.); (N.N.); (S.Y.); (M.I.A.); (A.F.H.); (Y.K.); (A.K.)
| | - Mohammad Salimian
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (K.C.); (N.N.); (S.Y.); (M.I.A.); (A.F.H.); (Y.K.); (A.K.)
| | - Muhammed Ikbal Arvas
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (K.C.); (N.N.); (S.Y.); (M.I.A.); (A.F.H.); (Y.K.); (A.K.)
| | - Ahmad F. Hedayat
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (K.C.); (N.N.); (S.Y.); (M.I.A.); (A.F.H.); (Y.K.); (A.K.)
| | - Yanni Kevas
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (K.C.); (N.N.); (S.Y.); (M.I.A.); (A.F.H.); (Y.K.); (A.K.)
| | - Anand Kadakia
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (K.C.); (N.N.); (S.Y.); (M.I.A.); (A.F.H.); (Y.K.); (A.K.)
| | - Tibor Kristian
- Department of Anesthesiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA;
- Veterans Affairs Medical Center, Baltimore, MD 21201, USA
| | - James W. Russell
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (K.C.); (N.N.); (S.Y.); (M.I.A.); (A.F.H.); (Y.K.); (A.K.)
- Veterans Affairs Medical Center, Baltimore, MD 21201, USA
- CAMC Institute for Academic Medicine, 415 Morris Street Suite 300, Charleston, WV 25301, USA
| |
Collapse
|
3
|
Dogan EO, Bouley J, Zhong J, Harkins AL, Keeler AM, Bosco DA, Brown RH, Henninger N. Genetic ablation of Sarm1 attenuates expression and mislocalization of phosphorylated TDP-43 after mouse repetitive traumatic brain injury. Acta Neuropathol Commun 2023; 11:206. [PMID: 38124145 PMCID: PMC10731794 DOI: 10.1186/s40478-023-01709-4] [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: 08/15/2023] [Accepted: 12/06/2023] [Indexed: 12/23/2023] Open
Abstract
Traumatic brain injury (TBI), particularly when moderate-to-severe and repetitive, is a strong environmental risk factor for several progressive neurodegenerative disorders. Mislocalization and deposition of transactive response DNA binding protein 43 (TDP-43) has been reported in both TBI and TBI-associated neurodegenerative diseases. It has been hypothesized that axonal pathology, an early event after TBI, may promote TDP-43 dysregulation and serve as a trigger for neurodegenerative processes. We sought to determine whether blocking the prodegenerative Sarm1 (sterile alpha and TIR motif containing 1) axon death pathway attenuates TDP-43 pathology after TBI. We subjected 111 male Sarm1 wild type, hemizygous, and knockout mice to moderate-to-severe repetitive TBI (rTBI) using a previously established injury paradigm. We conducted serial neurological assessments followed by histological analyses (NeuN, MBP, Iba-1, GFAP, pTDP-43, and AT8) at 1 month after rTBI. Genetic ablation of the Sarm1 gene attenuated the expression and mislocalization of phosphorylated TDP-43 (pTDP-43) and accumulation of pTau. In addition, Sarm1 knockout mice had significantly improved cortical neuronal and axonal integrity, functional deficits, and improved overall survival after rTBI. In contrast, removal of one Sarm1 allele delayed, but did not prevent, neurological deficits and neuroaxonal loss. Nevertheless, Sarm1 haploinsufficient mice showed significantly less microgliosis, pTDP-43 pathology, and pTau accumulation when compared to wild type mice. These data indicate that the Sarm1-mediated prodegenerative pathway contributes to pathogenesis in rTBI including the pathological accumulation of pTDP-43. This suggests that anti-Sarm1 therapeutics are a viable approach for preserving neurological function after moderate-to-severe rTBI.
Collapse
Affiliation(s)
- Elif O Dogan
- Department of Neurology, University of Massachusetts Chan Medical School, 55 Lake Ave, North, Worcester, MA, 01655, USA
| | - James Bouley
- Department of Neurology, University of Massachusetts Chan Medical School, 55 Lake Ave, North, Worcester, MA, 01655, USA
| | - Jianjun Zhong
- Department of Neurology, University of Massachusetts Chan Medical School, 55 Lake Ave, North, Worcester, MA, 01655, USA
- Department of Neurosurgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Ashley L Harkins
- Department of Neurology, University of Massachusetts Chan Medical School, 55 Lake Ave, North, Worcester, MA, 01655, USA
- Graduate Program in Neuroscience, Morningside Graduate School of Biomedical Sciences, University of Massachusetts Chan Medical School, Worcester, MA, 01655, USA
- Horae Gene Therapy Center, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
| | - Allison M Keeler
- Horae Gene Therapy Center, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
- Department of Pediatrics, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
- NeuroNexus Institute, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
| | - Daryl A Bosco
- Department of Neurology, University of Massachusetts Chan Medical School, 55 Lake Ave, North, Worcester, MA, 01655, USA
| | - Robert H Brown
- Department of Neurology, University of Massachusetts Chan Medical School, 55 Lake Ave, North, Worcester, MA, 01655, USA
| | - Nils Henninger
- Department of Neurology, University of Massachusetts Chan Medical School, 55 Lake Ave, North, Worcester, MA, 01655, USA.
- Department of Psychiatry, University of Massachusetts Chan Medical School, 55 Lake Ave, North, Worcester, MA, 01655, USA.
| |
Collapse
|