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Forsell P, Parrado Fernández C, Nilsson B, Sandin J, Nordvall G, Segerdahl M. Positive Allosteric Modulators of Trk Receptors for the Treatment of Alzheimer's Disease. Pharmaceuticals (Basel) 2024; 17:997. [PMID: 39204102 DOI: 10.3390/ph17080997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2024] [Revised: 07/19/2024] [Accepted: 07/25/2024] [Indexed: 09/03/2024] Open
Abstract
Neurotrophins are important regulators of neuronal and non-neuronal functions. As such, the neurotrophins and their receptors, the tropomyosin receptor kinase (Trk) family of receptor tyrosine kinases, has attracted intense research interest and their role in multiple diseases including Alzheimer's disease has been described. Attempts to administer neurotrophins to patients have been reported, but the clinical trials have so far have been hampered by side effects or a lack of clear efficacy. Thus, much of the focus during recent years has been on identifying small molecules acting as agonists or positive allosteric modulators (PAMs) of Trk receptors. Two examples of successful discovery and development of PAMs are the TrkA-PAM E2511 and the pan-Trk PAM ACD856. E2511 has been reported to have disease-modifying effects in preclinical models, whereas ACD856 demonstrates both a symptomatic and a disease-modifying effect in preclinical models. Both molecules have reached the stage of clinical development and were reported to be safe and well tolerated in clinical phase 1 studies, albeit with different pharmacokinetic profiles. These two emerging small molecules are interesting examples of possible novel symptomatic and disease-modifying treatments that could complement the existing anti-amyloid monoclonal antibodies for the treatment of Alzheimer's disease. This review aims to present the concept of positive allosteric modulators of the Trk receptors as a novel future treatment option for Alzheimer's disease and other neurodegenerative and cognitive disorders, and the current preclinical and clinical data supporting this new concept. Preclinical data indicate dual mechanisms, not only as cognitive enhancers, but also a tentative neurorestorative function.
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Affiliation(s)
- Pontus Forsell
- AlzeCure Pharma AB, Hälsovägen 7, 141 57 Huddinge, Sweden
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Alfred Nobels allé 23, 141 52 Huddinge, Sweden
| | - Cristina Parrado Fernández
- AlzeCure Pharma AB, Hälsovägen 7, 141 57 Huddinge, Sweden
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Alfred Nobels allé 23, 141 52 Huddinge, Sweden
| | - Boel Nilsson
- AlzeCure Pharma AB, Hälsovägen 7, 141 57 Huddinge, Sweden
| | - Johan Sandin
- AlzeCure Pharma AB, Hälsovägen 7, 141 57 Huddinge, Sweden
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Alfred Nobels allé 23, 141 52 Huddinge, Sweden
| | - Gunnar Nordvall
- AlzeCure Pharma AB, Hälsovägen 7, 141 57 Huddinge, Sweden
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Alfred Nobels allé 23, 141 52 Huddinge, Sweden
| | - Märta Segerdahl
- AlzeCure Pharma AB, Hälsovägen 7, 141 57 Huddinge, Sweden
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Alfred Nobels allé 23, 141 52 Huddinge, Sweden
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Chaldakov GN, Aloe L, Yanev SG, Fiore M, Tonchev AB, Vinciguerra M, Evtimov NT, Ghenev P, Dikranian K. Trackins (Trk-Targeting Drugs): A Novel Therapy for Different Diseases. Pharmaceuticals (Basel) 2024; 17:961. [PMID: 39065809 PMCID: PMC11279958 DOI: 10.3390/ph17070961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2024] [Revised: 06/19/2024] [Accepted: 07/17/2024] [Indexed: 07/28/2024] Open
Abstract
Many routes may lead to the transition from a healthy to a diseased phenotype. However, there are not so many routes to travel in the opposite direction; that is, therapy for different diseases. The following pressing question thus remains: what are the pathogenic routes and how can be they counteracted for therapeutic purposes? Human cells contain >500 protein kinases and nearly 200 protein phosphatases, acting on thousands of proteins, including cell growth factors. We herein discuss neurotrophins with pathogenic or metabotrophic abilities, particularly brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), pro-NGF, neurotrophin-3 (NT-3), and their receptor Trk (tyrosine receptor kinase; pronounced "track"). Indeed, we introduced the word trackins, standing for Trk-targeting drugs, that play an agonistic or antagonistic role in the function of TrkBBDNF, TrkCNT-3, TrkANGF, and TrkApro-NGF receptors. Based on our own published results, supported by those of other authors, we aim to update and enlarge our trackins concept, focusing on (1) agonistic trackins as possible drugs for (1a) neurotrophin-deficiency cardiometabolic disorders (hypertension, atherosclerosis, type 2 diabetes mellitus, metabolic syndrome, obesity, diabetic erectile dysfunction and atrial fibrillation) and (1b) neurodegenerative diseases (Alzheimer's disease, Parkinson's disease, and multiple sclerosis), and (2) antagonistic trackins, particularly TrkANGF inhibitors for prostate and breast cancer, pain, and arrhythmogenic right-ventricular dysplasia. Altogether, the druggability of TrkANGF, TrkApro-NGF, TrkBBDNF, and TrkCNT-3 receptors via trackins requires a further translational pursuit. This could provide rewards for our patients.
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Affiliation(s)
- George N. Chaldakov
- Departments of Anatomy and Cell Biology and Translational Stem Cell Biology, Research Institute, Medical University, 9002 Varna, Bulgaria
| | - Luigi Aloe
- Fondazione Iret, Tecnopolo R. Levi-Montalcini, Ozzano dell’Emilia, 40064 Bologna, Italy
| | - Stanislav G. Yanev
- Institute of Neurobiology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
| | - Marco Fiore
- Institute of Biochemistry and Cell Biology, National Research Council, IBBC-CNR, 00185 Rome, Italy
| | - Anton B. Tonchev
- Departments of Anatomy and Cell Biology and Translational Stem Cell Biology, Research Institute, Medical University, 9002 Varna, Bulgaria
| | - Manlio Vinciguerra
- Department of Translational Stem Cell Biology, Research Institute, Medical University, 9002 Varna, Bulgaria
| | - Nikolai T. Evtimov
- Department of Urology, University St Anna Hospital, 9002 Varna, Bulgaria
| | - Peter Ghenev
- Department of General and Clinical Pathology, Medical University, 9002 Varna, Bulgaria
| | - Krikor Dikranian
- Department of Neuroscience, Medical School, Washington University, St. Louis, MO 63110, USA
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Shen S, Zhang Y. Restoration of corneal epithelial barrier function: A possible target for corneal neovascularization. Ocul Surf 2024; 34:38-49. [PMID: 38901546 DOI: 10.1016/j.jtos.2024.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 06/10/2024] [Accepted: 06/11/2024] [Indexed: 06/22/2024]
Abstract
Corneal neovascularization (CoNV) is the second leading common cause of vision impairment worldwide and is a blinding pathological alteration brought on by ocular trauma, infection, and other factors. There are some limitations in the treatment of CoNV, hence it's critical to look into novel therapeutic targets. The corneal epithelial barrier, which is the initial barrier of the ocular surface, is an important structure that shields the eye from changes in the internal environment or invasion by the external environment. This study sought to collate evidence on the regulation of corneal epithelial barrier injury on the activation of vascular endothelial cells (VECs), basement membrane (BM) degradation, differentiation, migration, and proliferation of VECs, vascular maturation and stability, and other key processes in CoNV, so as to provide a novel concept for CoNV therapy targeting corneal epithelial barrier repair.
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Affiliation(s)
- Sitong Shen
- Department of Ophthalmology, The Second Hospital of Jilin University, 218 Ziqiang Street, Nanguan District, Changchun, Jilin Province, 130041, China
| | - Yan Zhang
- Department of Ophthalmology, The Second Hospital of Jilin University, 218 Ziqiang Street, Nanguan District, Changchun, Jilin Province, 130041, China; Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200080, China.
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Lin N, Chen X, Liu H, Gao N, Liu Z, Li J, Pflugfelder SC, Li DQ. Ectoine Enhances Mucin Production Via Restoring IL-13/IFN-γ Balance in a Murine Dry Eye Model. Invest Ophthalmol Vis Sci 2024; 65:39. [PMID: 38935032 PMCID: PMC11216279 DOI: 10.1167/iovs.65.6.39] [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: 04/08/2024] [Accepted: 05/25/2024] [Indexed: 06/28/2024] Open
Abstract
Purpose This study aimed to explore protective effects and potential mechanism of ectoine, a natural osmoprotectant, on ocular surface mucin production in dry eye disease. Methods A dry eye model was established in C57BL/6 mice exposed to desiccating stress (DS) with untreated (UT) mice as controls. DS mice were topically treated with 2.0% ectoine or PBS vehicle. Corneal epithelial defects were assessed by Oregon Green Dextran (OGD) fluorescent staining. Conjunctival goblet cells, ocular mucins, and T help (Th) cytokines were evaluated by immunofluorescent staining or ELISA, and RT-qPCR. Results Compared with UT mice, corneal epithelial defects were detected as strong punctate OGD fluorescent staining in DS mice with vehicle, whereas ectoine treatment largely reduced OGD staining to near-normal levels. Conjunctival goblet cell density and cell size decreased markedly in DS mice, but was significantly recovered by ectoine treatment. The protein production and mRNA expression of two gel-forming secreted MUC5AC and MUC2, and 4 transmembrane mucins, MUC1, MUC4, MUC16, and MUC15, largely decreased in DS mice, but was restored by ectoine. Furthermore, Th2 cytokine IL-13 was inhibited, whereas Th1 cytokine IFN-γ was stimulated at protein and mRNA levels in conjunctiva and draining cervical lymph nodes (CLNs) of DS mice, leading to decreased IL-13/IFN-γ ratio. Interestingly, 2.0% ectoine reversed their alternations and restored IL-13/IFN-γ balance. Conclusions Our findings demonstrate that topical ectoine significantly reduces corneal damage, and enhances goblet cell density and mucin production through restoring imbalanced IL-13/IFN-γ signaling in murine dry eye model. This suggests therapeutic potential of natural osmoprotectant ectoine for dry eye disease.
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Affiliation(s)
- Na Lin
- Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Xin Chen
- Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Haixia Liu
- Allergan, an AbbVie company, Irvine, California, United States
| | - Ning Gao
- Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States
- Department of Ophthalmology, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Zhao Liu
- Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States
- Department of Ophthalmology, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Jin Li
- Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Stephen C. Pflugfelder
- Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States
| | - De-Quan Li
- Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States
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Alam J, Yaman E, Silva GCV, Chen R, de Paiva CS, Stepp MA, Pflugfelder SC. Single cell analysis of short-term dry eye induced changes in cornea immune cell populations. Front Med (Lausanne) 2024; 11:1362336. [PMID: 38560382 PMCID: PMC10978656 DOI: 10.3389/fmed.2024.1362336] [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: 12/28/2023] [Accepted: 02/28/2024] [Indexed: 04/04/2024] Open
Abstract
Background Dry eye causes corneal inflammation, epitheliopathy and sensorineural changes. This study evaluates the hypothesis that dry eye alters the percentages and transcriptional profiles of immune cell populations in the cornea. Methods Desiccating stress (DS) induced dry eye was created by pharmacologic suppression of tear secretion and exposure to drafty low humidity environment. Expression profiling of corneal immune cells was performed by single-cell RNA sequencing (scRNA-seq). Cell differentiation trajectories and cell fate were modeled through RNA velocity analysis. Confocal microscopy was used to immunodetect corneal immune cells. Irritation response to topical neurostimulants was assessed. Results Twelve corneal immune cell populations based on their transcriptional profiles were identified at baseline and consist of monocytes, resident (rMP) and MMP12/13 high macrophages, dendritic cells (cDC2), neutrophils, mast cells, pre T/B cells, and innate (γDT, ILC2, NK) and conventional T and B lymphocytes. T cells and resident macrophages (rMP) were the largest populations in the normal cornea comprising 18.6 and 18.2 percent, respectively. rMP increased to 55.2% of cells after 5 days of DS. Significant changes in expression of 1,365 genes (adj p < 0.0001) were noted in rMP with increases in cytokines and chemokines (Tnf, Cxcl1, Ccl12, Il1rn), inflammatory markers (Vcam, Adam17, Junb), the TAM receptor (Mertk), and decreases in complement and MHCII genes. A differentiation trajectory from monocytes to terminal state rMP was found. Phagocytosis, C-type lectin receptor signaling, NF-kappa B signaling and Toll-like receptor signaling were among the pathways with enhanced activity in these cells. The percentage of MRC1+ rMPs increased in the cornea and they were observed in the basal epithelium adjacent to epithelial nerve plexus. Concentration of the chemokine CXCL1 increased in the cornea and it heightened irritation/pain responses to topically applied hypertonic saline. Conclusion These findings indicate that DS recruits monocytes that differentiate to macrophages with increased expression of inflammation associated genes. The proximity of these macrophages to cornea nerves and their expression of neurosensitizers suggests they contribute to the corneal sensorineural changes in dry eye.
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Affiliation(s)
- Jehan Alam
- Ocular Surface Center, Department of Ophthalmology, Baylor College of Medicine, Houston, TX, United States
| | - Ebru Yaman
- Ocular Surface Center, Department of Ophthalmology, Baylor College of Medicine, Houston, TX, United States
| | - Gerda Cristal Villalba Silva
- Human Genome Sequencing Center, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Rui Chen
- Human Genome Sequencing Center, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Cintia S. de Paiva
- Ocular Surface Center, Department of Ophthalmology, Baylor College of Medicine, Houston, TX, United States
| | - Mary Ann Stepp
- Departments of Anatomy, Regenerative Biology and Ophthalmology, The George Washington University Medical School and Health Sciences, Washington, DC, United States
| | - Stephen C. Pflugfelder
- Ocular Surface Center, Department of Ophthalmology, Baylor College of Medicine, Houston, TX, United States
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Thompson T, Pewklang T, Piyanuch P, Wanichacheva N, Kamkaew A, Burgess K. A fluorescent electrophile for CLIPS: self indicating TrkB binders. Org Biomol Chem 2024; 22:506-512. [PMID: 38111346 PMCID: PMC10863675 DOI: 10.1039/d3ob01654d] [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] [Indexed: 12/20/2023]
Abstract
Combination of cysteine-containing peptides with electrophiles provides efficient access to cyclo-organopeptides. However, there are no routes to intrinsically fluorescent cyclo-organopeptides containing robust, brilliant fluorophores emitting at wavelengths longer than cellular autofluorescence. We show such fluorescent cyclo-organopeptides can be made via SNAr reactions of cysteine-containing peptides with a BODIPY system. Seven compounds of this type were prepared to test as probes; six contained peptide sequences corresponding to loop regions in brain-derived neurotrophic factor and neurotrophic factor 4 (BDNF and NT-4) which bind tropomyocin receptor kinase B (TrkB). Cellular assays in serum-free media indicated two of the six key compounds induced survival of HEK293 cells stably transfected with TrkB whereas a control did not. The two compounds inducing cell survival bound TrkB on those cells (Kd ∼40 and 47 nM), illustrating how intrinsically fluorescent cyclo-organopeptides can be assayed for quantifiable binding to surface receptors in cell membrane environments.
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Affiliation(s)
- Tye Thompson
- Department of Chemistry, Texas A & M University, Box 30012, College Station, TX 77842-3012, USA.
| | - Thitima Pewklang
- Department of Chemistry, Texas A & M University, Box 30012, College Station, TX 77842-3012, USA.
- School of Chemistry, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
| | - Pornthip Piyanuch
- Department of Chemistry, Faculty of Science, Silpakorn University, Nakhon Pathom 73000, Thailand
| | - Nantanit Wanichacheva
- Department of Chemistry, Faculty of Science, Silpakorn University, Nakhon Pathom 73000, Thailand
| | - Anyanee Kamkaew
- School of Chemistry, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
| | - Kevin Burgess
- Department of Chemistry, Texas A & M University, Box 30012, College Station, TX 77842-3012, USA.
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Abu-Romman A, Scholand KK, Pal-Ghosh S, Yu Z, Kelagere Y, Yazdanpanah G, Kao WWY, Coulson-Thomas VJ, Stepp MA, de Paiva CS. Conditional deletion of CD25 in the corneal epithelium reveals sex differences in barrier disruption. Ocul Surf 2023; 30:57-72. [PMID: 37516317 PMCID: PMC10812880 DOI: 10.1016/j.jtos.2023.07.008] [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: 05/02/2023] [Revised: 07/06/2023] [Accepted: 07/25/2023] [Indexed: 07/31/2023]
Abstract
PURPOSE IL-2 promotes activation, clonal expansion, and deletion of T cells. IL-2 signals through its heterotrimeric receptor (IL-2R) consisting of the CD25, CD122 and CD132 chains. CD25 knockout (KO) mice develop Sjögren Syndrome-like disease. This study investigates whether corneal CD25/IL-2 signaling is critical for ocular health. METHODS Eyes from C57BL/6 mice were collected and prepared for immunostaining or in-situ hybridization. Bulk RNA sequencing was performed on the corneal epithelium from wild-type and CD25KO mice. We generated a conditional corneal-specific deletion of CD25 in the corneal epithelium (CD25Δ/ΔCEpi). Corneal barrier function was evaluated based on the uptake of a fluorescent dye. Mice were subjected to unilateral corneal debridement, followed by epithelial closure over time. RESULTS In C57BL/6 mice, CD25 mRNA was expressed in ocular tissues. Protein expression of CD25, CD122, and CD132 was confirmed in the corneal epithelium. Delayed corneal re-epithelization was seen in female but not male CD25KO mice. There were 771 differentially expressed genes in the corneal epithelium of CD25KO compared to wild-type mice. While barrier function is disrupted in CD25Δ/ΔCEpi mice, re-epithelialization rates are not delayed. CONCLUSIONS All three chains of the IL-2R are expressed in the corneal epithelium. Our results indicate for the first time, deleting CD25 systemically in all tissues in the mouse and deleting CD25 locally in just the corneal epithelium compromises corneal epithelial barrier function, leading to dry eye disease in female mice. Future studies are needed to delineate the pathways used by IL-2 signaling to influence cornea homeostasis.
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Affiliation(s)
- Anmar Abu-Romman
- Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, TX, United States.
| | - Kaitlin K Scholand
- Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, TX, United States; Department of Biosciences, Rice University, Houston, TX, United States.
| | - Sonali Pal-Ghosh
- Department of Anatomy and Cell Biology, The George Washington University School of Medicine and Health Sciences, Washington, DC, United States.
| | - Zhiyuan Yu
- Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, TX, United States.
| | - Yashaswini Kelagere
- Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, TX, United States.
| | - Ghasem Yazdanpanah
- Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, TX, United States.
| | - Winston W-Y Kao
- Department of Ophthalmology, University of Cincinnati, Cincinnati, OH, United States.
| | | | - Mary Ann Stepp
- Department of Anatomy and Cell Biology, The George Washington University School of Medicine and Health Sciences, Washington, DC, United States; Department of Ophthalmology, The George Washington University School of Medicine and Health Sciences, Washington, DC, United States.
| | - Cintia S de Paiva
- Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, TX, United States; Department of Biosciences, Rice University, Houston, TX, United States.
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8
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Panthagani J, Suleiman K, Vincent RC, Ong HS, Wallace GR, Rauz S. Conjunctival transcriptomics in ocular mucous membrane pemphigoid. Ocul Surf 2023; 30:142-149. [PMID: 37690517 DOI: 10.1016/j.jtos.2023.09.005] [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: 05/19/2023] [Revised: 09/07/2023] [Accepted: 09/07/2023] [Indexed: 09/12/2023]
Abstract
PURPOSE Ocular Mucous Membrane Pemphigoid (OcMMP) is an orphan disease characterized by chronic autoimmune-driven conjunctival inflammation leading to progressive scarring, debilitating symptoms, and blinding sequelae. This feasibility study aims to demonstrate conjunctival genetic transcriptomic analyses as a putative tool for interrogation of pathogenic signaling pathways in OcMMP. METHODS Conjunctival RNA profiling using the NanoString nCounter Human Fibrosis panel was undertaken on RNA extracted from conjunctival swabs obtained from 6 MMP patients (8 eyes; 4 M/2F; median age 78 [range 64-84] years); and 8 age-matched control participants (15 eyes; 3 M/5F; median age 69.5 [range 69-88] years). Data from 770 genes were analyzed with ROSALIND HyperScale architecture and stratified according to the level of clinically visible bulbar conjunctival inflammation. Normalization, fold-changes (≥+1.5-fold or ≤ -1.5-fold) and p-values adjustment (<0.05) using the Benjamini-Hochberg method were calculated. RESULTS 93 differentially expressed genes (DEGs) were observed between OcMMP versus controls of which 48 were upregulated, and 45 downregulated. The top 4 upregulated DEGs represented fibrosis (COL3A1, COL1A1, FN1 and THBS1) while the key under-expressed genes (SCIN, HMGS2, XCL1/2) were indicative of ocular surface failure (goblet cell loss, keratinization, vulnerability to secondary infections). Forty-four pathways had a global significance score ≥2, the most significant being those related to extracellular matrix (ECM) remodeling, synthesis, and degradation. These pathways were accentuated in eyes with visible inflammation. CONCLUSIONS NanoString methodology acquired via a simple conjunctival swab identifies profibrotic genes in OcMMP group and differentiates inflamed eyes. Longitudinal sampling and following investigative intervention will further mechanistic insight and development of novel biomarkers to monitor disease progression.
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Affiliation(s)
- Jesse Panthagani
- Academic Unit of Ophthalmology, Institute of Inflammation and Ageing, University of Birmingham, UK; Birmingham and Midland Eye Centre, Sandwell and West Birmingham NHS Trust, Birmingham, UK
| | - Kusy Suleiman
- Academic Unit of Ophthalmology, Institute of Inflammation and Ageing, University of Birmingham, UK; Birmingham and Midland Eye Centre, Sandwell and West Birmingham NHS Trust, Birmingham, UK
| | - Rachel C Vincent
- Academic Unit of Ophthalmology, Institute of Inflammation and Ageing, University of Birmingham, UK
| | - Hon Shing Ong
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore; Corneal and External Diseases Department, Singapore National Eye Centre, Singapore, Singapore; Ophthalmology & Visual Sciences Academic Clinical Programme, Duke-NUS Medical School, Singapore
| | - Graham R Wallace
- Academic Unit of Ophthalmology, Institute of Inflammation and Ageing, University of Birmingham, UK
| | - Saaeha Rauz
- Academic Unit of Ophthalmology, Institute of Inflammation and Ageing, University of Birmingham, UK; Birmingham and Midland Eye Centre, Sandwell and West Birmingham NHS Trust, Birmingham, UK.
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9
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A, B, C's of Trk Receptors and Their Ligands in Ocular Repair. Int J Mol Sci 2022; 23:ijms232214069. [PMID: 36430547 PMCID: PMC9695972 DOI: 10.3390/ijms232214069] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 10/29/2022] [Accepted: 11/06/2022] [Indexed: 11/16/2022] Open
Abstract
Neurotrophins are a family of closely related secreted proteins that promote differentiation, development, and survival of neurons, which include nerve growth factor (NGF), brain-derived neurotrophic factor, neurotrophin-3, and neurotrophin-4. All neurotrophins signal through tropomyosin receptor kinases (TrkA, TrkB, and TrkC) which are more selective to NGF, brain-derived neurotrophic factor, and neurotrophin-3, respectively. NGF is the most studied neurotrophin in the ocular surface and a human recombinant NGF has reached clinics, having been approved to treat neurotrophic keratitis. Brain-derived neurotrophic factor, neurotrophin-3, and neurotrophin-4 are less studied neurotrophins in the ocular surface, even though brain-derived neurotrophic factor is well characterized in glaucoma, retina, and neuroscience. Recently, neurotrophin analogs with panTrk activity and TrkC selectivity have shown promise as novel drugs for treating dry eye disease. In this review, we discuss the biology of the neurotrophin family, its role in corneal homeostasis, and its use in treating ocular surface diseases. There is an unmet need to investigate parenteral neurotrophins and its analogs that activate TrkB and TrkC selectively.
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