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Elmounedi N, Bahloul W, Keskes H. Current Therapeutic Strategies of Intervertebral Disc Regenerative Medicine. Mol Diagn Ther 2024:10.1007/s40291-024-00729-7. [PMID: 39158834 DOI: 10.1007/s40291-024-00729-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/30/2024] [Indexed: 08/20/2024]
Abstract
Intervertebral disc degeneration (IDD) is one of the most frequent causes of low back pain. No treatment is currently available to delay the progression of IDD. Conservative treatment or surgical interventions is only used to target the symptoms of IDD rather than treat the underlying cause. Currently, numerous potential therapeutic strategies are available, including molecular therapy, gene therapy, and cell therapy. However, the hostile environment of degenerated discs is a major problem that has hindered the clinical applicability of such approaches. In this regard, the design of drugs using alternative delivery systems (macro-, micro-, and nano-sized particles) may resolve this problem. These can protect and deliver biomolecules along with helping to improve the therapeutic effect of drugs via concentrating, protecting, and prolonging their presence in the degenerated disc. This review summarizes the research progress of diagnosis and the current options for treating IDD.
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Affiliation(s)
- Najah Elmounedi
- Cell Therapy and Experimental Surgery of Musculoskeletal System LR18SP11 Lab, Sfax Faculty of Medicine, Majida Boulila Road, 3029, Sfax, Tunisia.
| | - Walid Bahloul
- Cell Therapy and Experimental Surgery of Musculoskeletal System LR18SP11 Lab, Sfax Faculty of Medicine, Majida Boulila Road, 3029, Sfax, Tunisia
- Department of Orthopedics and Traumatology, CHU Habib Bourguiba, Sfax, Tunisia
| | - Hassib Keskes
- Cell Therapy and Experimental Surgery of Musculoskeletal System LR18SP11 Lab, Sfax Faculty of Medicine, Majida Boulila Road, 3029, Sfax, Tunisia
- Department of Orthopedics and Traumatology, CHU Habib Bourguiba, Sfax, Tunisia
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Wang L, Jin K, Li N, Xu P, Yuan H, Ramaraju H, Hollister SJ, Fan Y. Innovative design of minimal invasive biodegradable poly(glycerol-dodecanoate) nucleus pulposus scaffold with function regeneration. Nat Commun 2023; 14:3865. [PMID: 37391454 PMCID: PMC10313828 DOI: 10.1038/s41467-023-39604-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 06/21/2023] [Indexed: 07/02/2023] Open
Abstract
Minimally invasive biodegradable implants with regeneration have been a frontier trend in clinic. Degeneration of nucleus pulposus (NP) is irreversible in most of spine diseases, and traditional spinal fusion or discectomy usually injure adjacent segments. Here, an innovative minimally invasive biodegradable NP scaffold with function regeneration inspired by cucumber tendril is developed using shape memory polymer poly(glycerol-dodecanoate) (PGD), whose mechanical property is controlled to the similar with human NP by adjusting synthetic parameters. The chemokine stromal cell-derived factor-1α (SDF-1α) is immobilized to the scaffold recruiting autologous stem cells from peripheral tissue, which has better ability of maintaining disc height, recruiting autologous stem cells, and inducing regeneration of NP in vivo compared to PGD without chemokine group and hydrogel groups significantly. It provides an innovative way to design minimally invasive implants with biodegradation and functional recovery, especially for irreversible tissue injury, including NP, cartilage and so on.
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Affiliation(s)
- Lizhen Wang
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Kaixiang Jin
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Nan Li
- Department of Spine Surgery, Beijing Jishuitan Hospital, The Fourth Clinical Medical College of Peking University, Beijing, 100035, China
| | - Peng Xu
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Hao Yuan
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Harsha Ramaraju
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Drive, Atlanta, GA, 30332, USA
| | - Scott J Hollister
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Drive, Atlanta, GA, 30332, USA
| | - Yubo Fan
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, School of Engineering Medicine, Beihang University, Beijing, 100083, China.
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Therapeutic Strategies for IVD Regeneration through Hyaluronan/SDF-1-Based Hydrogel and Intravenous Administration of MSCs. Int J Mol Sci 2021; 22:ijms22179609. [PMID: 34502517 PMCID: PMC8431759 DOI: 10.3390/ijms22179609] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 08/28/2021] [Accepted: 08/30/2021] [Indexed: 12/19/2022] Open
Abstract
Intervertebral disc (IVD) degeneration involves a complex cascade of events, including degradation of the native extracellular matrix, loss of water content, and decreased cell numbers. Cell recruitment strategies for the IVD have been increasingly explored, aiming to recruit either endogenous or transplanted cells. This study evaluates the IVD therapeutic potential of a chemoattractant delivery system (HAPSDF5) that combines a hyaluronan-based thermoreversible hydrogel (HAP) and the chemokine stromal cell derived factor-1 (SDF-1). HAPSDF5 was injected into the IVD and was combined with an intravenous injection of mesenchymal stem/stromal cells (MSCs) in a pre-clinical in vivo IVD lesion model. The local and systemic effects were evaluated two weeks after treatment. The hydrogel by itself (HAP) did not elicit any adverse effect, showing potential to be administrated by intradiscal injection. HAPSDF5 induced higher cell numbers, but no evidence of IVD regeneration was observed. MSCs systemic injection seemed to exert a role in IVD regeneration to some extent through a paracrine effect, but no synergies were observed when HAPSDF5 was combined with MSCs. Overall, this study shows that although the injection of chemoattractant hydrogels and MSC recruitment are feasible approaches for IVD, IVD regeneration using this strategy needs to be further explored before successful clinical translation.
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Platelet-Derived Growth Factor Stimulated Migration of Bone Marrow Mesenchymal Stem Cells into an Injectable Gelatin-Hydroxyphenyl Propionic Acid Matrix. Biomedicines 2021; 9:biomedicines9020203. [PMID: 33671438 PMCID: PMC7923108 DOI: 10.3390/biomedicines9020203] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 01/26/2021] [Accepted: 02/01/2021] [Indexed: 12/22/2022] Open
Abstract
Bone marrow mesenchymal stem cells (bMSCs) are responsible in the repair of injured tissue through differentiation into multiple cell types and secretion of paracrine factors, and thus have a broad application profile in tissue engineering/regenerative medicine, especially for the musculoskeletal system. The lesion due to injury or disease may be a closed irregular-shaped cavity deep within tissue necessitating an injectable biomaterial permissive of host (endogenous) cell migration, proliferation and differentiation. Gelatin-hydroxyphenyl propionic acid (Gtn-HPA) is a natural biopolymer hydrogel which is covalently cross-linked by horseradish peroxidase (HRP) and hydrogen peroxide (H2O2) in situ and can be delivered to the lesion by needle injection. Growth factors and cytokines can be directly incorporated into the gel or into nano- and micro-particles, which can be employed for sustained release of biomolecules while maintaining their bioactivity. In this study, we selected polyelectrolyte complex nanoparticles (PCNs) prepared with dextran sulfate and chitosan as the carrier for platelet-derived growth factor (PDGF)-BB and stromal cell-derived factor (SDF)-1α, which have been tested effectively in recruiting stem cells. Our in vitro results showed a high degree of viability of bMSCs through the process of Gtn-HPA covalent cross-linking gelation. The Gtn-HPA matrix was highly permissive of bMSC migration, proliferation, and differentiation. PDGF-BB (20 ng/mL) directly incorporated into the gel and, alternatively, released from PCNs stimulated bMSC migration and proliferation. There were only small differences in the results for the direct incorporation of PDGF into the gel compared with its release from PCNs, and for increased doses of the growth factor (200 ng/mL and 2 µg/mL). In contrast, SDF-1α elicited an increase in migration and proliferation only when released from PCNs; its effect on migration was notably less than PDGF-BB. The in vitro results demonstrate that PDGF-BB substantially increases migration of bMSCs into Gtn-HPA and their proliferation in the gel, and that these benefits can be derived from incorporation of a relatively low dose of the growth factor directly into the gel. These findings commend the use of Gtn-HPA/PDGF-BB as an injectable therapeutic agent to treat defects in musculoskeletal tissues.
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Vainieri ML, Alini M, Yayon A, van Osch GJVM, Grad S. Mechanical Stress Inhibits Early Stages of Endogenous Cell Migration: A Pilot Study in an Ex Vivo Osteochondral Model. Polymers (Basel) 2020; 12:polym12081754. [PMID: 32781503 PMCID: PMC7466115 DOI: 10.3390/polym12081754] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 07/25/2020] [Accepted: 08/03/2020] [Indexed: 01/07/2023] Open
Abstract
Cell migration has a central role in osteochondral defect repair initiation and biomaterial-mediated regeneration. New advancements to reestablish tissue function include biomaterials and factors promoting cell recruitment, differentiation and tissue integration, but little is known about responses to mechanical stimuli. In the present pilot study, we tested the influence of extrinsic forces in combination with biomaterials releasing chemoattractant signals on cell migration. We used an ex vivo mechanically stimulated osteochondral defect explant filled with fibrin/hyaluronan hydrogel, in presence or absence of platelet-derived growth factor-BB or stromal cell-derived factor 1, to assess endogenous cell recruitment into the wound site. Periodic mechanical stress at early time point negatively influenced cell infiltration compared to unloaded samples, and the implementation of chemokines to increase cell migration was not efficient to overcome this negative effect. The gene expression at 15 days of culture indicated a marked downregulation of matrix metalloproteinase (MMP)13 and MMP3, a decrease of β1 integrin and increased mRNA levels of actin in osteochondral samples exposed to complex load. This work using an ex vivo osteochondral mechanically stimulated advanced platform demonstrated that recurrent mechanical stress at early time points impeded cell migration into the hydrogel, providing a unique opportunity to improve our understanding on management of joint injury.
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Affiliation(s)
- Maria L. Vainieri
- AO Research Institute Davos, 7270 Davos, Switzerland; (M.L.V.); (M.A.)
- Department of Orthopaedics, Erasmus MC, University Medical Center Rotterdam, 3015 CN Rotterdam, The Netherlands;
| | - Mauro Alini
- AO Research Institute Davos, 7270 Davos, Switzerland; (M.L.V.); (M.A.)
| | - Avner Yayon
- ProCore Ltd., Weizmann Science Park, 7 Golda Meir St., Ness Ziona 70400, Israel;
| | - Gerjo J. V. M. van Osch
- Department of Orthopaedics, Erasmus MC, University Medical Center Rotterdam, 3015 CN Rotterdam, The Netherlands;
- Department of Otorhinolaryngology, Erasmus MC, University Medical Center Rotterdam, 3015 CN Rotterdam, The Netherlands
- Department of Biomedical Engineering, University of Technology Delft, 2628 CD Delft, The Netherlands
| | - Sibylle Grad
- AO Research Institute Davos, 7270 Davos, Switzerland; (M.L.V.); (M.A.)
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
- Correspondence: ; Tel.: +41-81-4142480
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Frapin L, Clouet J, Chédeville C, Moraru C, Samarut E, Henry N, André M, Bord E, Halgand B, Lesoeur J, Fusellier M, Guicheux J, Le Visage C. Controlled release of biological factors for endogenous progenitor cell migration and intervertebral disc extracellular matrix remodelling. Biomaterials 2020; 253:120107. [PMID: 32450408 DOI: 10.1016/j.biomaterials.2020.120107] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 04/20/2020] [Accepted: 05/06/2020] [Indexed: 02/06/2023]
Abstract
The recent description of resident stem/progenitor cells in degenerated intervertebral discs (IVDs) supports the notion that their regenerative capacities could be harnessed to stimulate endogenous repair of the nucleus pulposus (NP). In this study, we developed a delivery system based on pullulan microbeads (PMBs) for sequential release of the chemokine CCL-5 to recruit these disc stem/progenitor cells to the NP tissue, followed by the release of the growth factors TGF-β1 and GDF-5 to induce the synthesis of a collagen type II- and aggrecan-rich extracellular matrix (ECM). Bioactivity of released CCL5 on human adipose-derived stem cells (hASCs), selected to mimic disc stem/progenitors, was demonstrated using a Transwell® chemotaxis assay. The regenerative effects of loaded PMBs were investigated in ex vivo spontaneously degenerated ovine IVDs. Fluorescent hASCs were seeded on the top cartilaginous endplates (CEPs); the degenerated NPs were injected with PMBs loaded with CCL5, TGF-β1, and GDF-5; and the IVDs were then cultured for 3, 7, and 28 days to allow for cell migration and disc regeneration. The PMBs exhibited sustained release of biological factors for 21 days. Ex vivo migration of seeded hASCs from the CEP toward the NP was demonstrated, with the cells migrating a significantly greater distance when loaded PMBs were injected (5.8 ± 1.3 mm vs. 3.5 ± 1.8 mm with no injection of PMBs). In ovine IVDs, the overall NP cellularity, the collagen type II and the aggrecan staining intensities, and the Tie2+ progenitor cell density in the NP were increased at day 28 compared to the control groups. Considered together, PMBs loaded with CCL5/TGF-β1/GDF-5 constitute an innovative and promising strategy for controlled release of growth factors to promote cell recruitment and extracellular matrix remodelling.
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Affiliation(s)
- Leslie Frapin
- Inserm, UMR 1229, RMeS, Regenerative Medicine and Skeleton, Université de Nantes, ONIRIS, Nantes, F-44042, France; Université de Nantes, UFR Odontologie, Nantes, F-44042, France
| | - Johann Clouet
- Inserm, UMR 1229, RMeS, Regenerative Medicine and Skeleton, Université de Nantes, ONIRIS, Nantes, F-44042, France; Université de Nantes, UFR Odontologie, Nantes, F-44042, France; CHU Nantes, Pharmacie Centrale, PHU 11, Nantes, F-44093, France; Université de Nantes, UFR Sciences Biologiques et Pharmaceutiques, Nantes, F-44035, France
| | - Claire Chédeville
- Inserm, UMR 1229, RMeS, Regenerative Medicine and Skeleton, Université de Nantes, ONIRIS, Nantes, F-44042, France; Université de Nantes, UFR Odontologie, Nantes, F-44042, France
| | - Constantin Moraru
- Inserm, UMR 1229, RMeS, Regenerative Medicine and Skeleton, Université de Nantes, ONIRIS, Nantes, F-44042, France; Université de Nantes, UFR Odontologie, Nantes, F-44042, France; CHU Nantes, Service de Neurotraumatologie, PHU4 OTONN, Nantes, F-44093, France
| | - Edouard Samarut
- Inserm, UMR 1229, RMeS, Regenerative Medicine and Skeleton, Université de Nantes, ONIRIS, Nantes, F-44042, France; Université de Nantes, UFR Odontologie, Nantes, F-44042, France; CHU Nantes, Service de Neurotraumatologie, PHU4 OTONN, Nantes, F-44093, France
| | - Nina Henry
- Inserm, UMR 1229, RMeS, Regenerative Medicine and Skeleton, Université de Nantes, ONIRIS, Nantes, F-44042, France; Université de Nantes, UFR Odontologie, Nantes, F-44042, France
| | - Manon André
- Inserm, UMR 1229, RMeS, Regenerative Medicine and Skeleton, Université de Nantes, ONIRIS, Nantes, F-44042, France; Université de Nantes, UFR Odontologie, Nantes, F-44042, France; SC3M -"Electron Microscopy, Microcharacterization, and Functional Morphohistology Imaging" Core Facility, Structure Fédérative de Recherche François Bonamy, INSERM - UMS016, CNRS 3556, CHU Nantes, Université de Nantes, Nantes, Nantes, F-04402, France
| | - Eric Bord
- Inserm, UMR 1229, RMeS, Regenerative Medicine and Skeleton, Université de Nantes, ONIRIS, Nantes, F-44042, France; Université de Nantes, UFR Odontologie, Nantes, F-44042, France; CHU Nantes, Service de Neurotraumatologie, PHU4 OTONN, Nantes, F-44093, France
| | - Boris Halgand
- Inserm, UMR 1229, RMeS, Regenerative Medicine and Skeleton, Université de Nantes, ONIRIS, Nantes, F-44042, France; Université de Nantes, UFR Odontologie, Nantes, F-44042, France; CHU Nantes, PHU4 OTONN, Nantes, F-44093, France
| | - Julie Lesoeur
- Inserm, UMR 1229, RMeS, Regenerative Medicine and Skeleton, Université de Nantes, ONIRIS, Nantes, F-44042, France; Université de Nantes, UFR Odontologie, Nantes, F-44042, France; SC3M -"Electron Microscopy, Microcharacterization, and Functional Morphohistology Imaging" Core Facility, Structure Fédérative de Recherche François Bonamy, INSERM - UMS016, CNRS 3556, CHU Nantes, Université de Nantes, Nantes, Nantes, F-04402, France
| | - Marion Fusellier
- Inserm, UMR 1229, RMeS, Regenerative Medicine and Skeleton, Université de Nantes, ONIRIS, Nantes, F-44042, France; Université de Nantes, UFR Odontologie, Nantes, F-44042, France; Department of Diagnostic Imaging, CRIP, National Veterinary School (ONIRIS), Nantes, F-44307, France
| | - Jérôme Guicheux
- Inserm, UMR 1229, RMeS, Regenerative Medicine and Skeleton, Université de Nantes, ONIRIS, Nantes, F-44042, France; Université de Nantes, UFR Odontologie, Nantes, F-44042, France; SC3M -"Electron Microscopy, Microcharacterization, and Functional Morphohistology Imaging" Core Facility, Structure Fédérative de Recherche François Bonamy, INSERM - UMS016, CNRS 3556, CHU Nantes, Université de Nantes, Nantes, Nantes, F-04402, France; CHU Nantes, PHU4 OTONN, Nantes, F-44093, France.
| | - Catherine Le Visage
- Inserm, UMR 1229, RMeS, Regenerative Medicine and Skeleton, Université de Nantes, ONIRIS, Nantes, F-44042, France; Université de Nantes, UFR Odontologie, Nantes, F-44042, France.
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Yao CH, Chen KY, Cheng MH, Chen YS, Huang CH. Effect of genipin crosslinked chitosan scaffolds containing SDF-1 on wound healing in a rat model. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2020; 109:110368. [DOI: 10.1016/j.msec.2019.110368] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 10/22/2019] [Accepted: 10/24/2019] [Indexed: 10/25/2022]
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Abstract
STUDY DESIGN Review article. OBJECTIVE A review of the literature on current strategies utilized in intervertebral regeneration and repair efforts. METHODS A review of the literature and analysis of the data to provide an updated review on current concepts of intervertebral disc repair and regeneration efforts. RESULTS Multiple regenerative strategies for intervertebral disc regeneration are being employed to reduce pain and improve quality of life. Current promising strategies include molecular therapy, gene therapy, cell-based therapy, and augmentation with biomaterials. Multiple clinical trials studying biologic, cell-based, and scaffold-based injectable therapies are currently being investigated. CONCLUSION Low back pain due to intervertebral disc disease represents a significant health and societal burden. Current promising strategies include molecular therapy, gene therapy, cell-based therapy, and augmentation with biomaterials. To date, there are no Food and Drug Administration-approved intradiscal therapies for discogenic back pain, and there are no large randomized trials that have shown clinically significant improvement with any investigational regenerative treatment. Multiple clinical trials studying biologic, cell-based, or scaffold-based injectable therapies are being currently investigated.
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Affiliation(s)
- Derek G. Ju
- Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | | | - Hyun W. Bae
- Cedars-Sinai Medical Center, Los Angeles, CA, USA
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Elmansi AM, Awad ME, Eisa NH, Kondrikov D, Hussein KA, Aguilar-Pérez A, Herberg S, Periyasamy-Thandavan S, Fulzele S, Hamrick MW, McGee-Lawrence ME, Isales CM, Volkman BF, Hill WD. What doesn't kill you makes you stranger: Dipeptidyl peptidase-4 (CD26) proteolysis differentially modulates the activity of many peptide hormones and cytokines generating novel cryptic bioactive ligands. Pharmacol Ther 2019; 198:90-108. [PMID: 30759373 PMCID: PMC7883480 DOI: 10.1016/j.pharmthera.2019.02.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Dipeptidyl peptidase 4 (DPP4) is an exopeptidase found either on cell surfaces where it is highly regulated in terms of its expression and surface availability (CD26) or in a free/circulating soluble constitutively available and intrinsically active form. It is responsible for proteolytic cleavage of many peptide substrates. In this review we discuss the idea that DPP4-cleaved peptides are not necessarily inactivated, but rather can possess either a modified receptor selectivity, modified bioactivity, new antagonistic activity, or even a novel activity relative to the intact parent ligand. We examine in detail five different major DPP4 substrates: glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), peptide tyrosine-tyrosine (PYY), and neuropeptide Y (NPY), and stromal derived factor 1 (SDF-1 aka CXCL12). We note that discussion of the cleaved forms of these five peptides are underrepresented in the research literature, and are both poorly investigated and poorly understood, representing a serious research literature gap. We believe they are understudied and misinterpreted as inactive due to several factors. This includes lack of accurate and specific quantification methods, sample collection techniques that are inherently inaccurate and inappropriate, and a general perception that DPP4 cleavage inactivates its ligand substrates. Increasing evidence points towards many DPP4-cleaved ligands having their own bioactivity. For example, GLP-1 can work through a different receptor than GLP-1R, DPP4-cleaved GIP can function as a GIP receptor antagonist at high doses, and DPP4-cleaved PYY, NPY, and CXCL12 can have different receptor selectivity, or can bind novel, previously unrecognized receptors to their intact ligands, resulting in altered signaling and functionality. We believe that more rigorous research in this area could lead to a better understanding of DPP4's role and the biological importance of the generation of novel cryptic ligands. This will also significantly impact our understanding of the clinical effects and side effects of DPP4-inhibitors as a class of anti-diabetic drugs that potentially have an expanding clinical relevance. This will be specifically relevant in targeting DPP4 substrate ligands involved in a variety of other major clinical acute and chronic injury/disease areas including inflammation, immunology, cardiology, stroke, musculoskeletal disease and injury, as well as cancer biology and tissue maintenance in aging.
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Affiliation(s)
- Ahmed M Elmansi
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC 29403, United States; Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC 29403, United States
| | - Mohamed E Awad
- Department of Oral Biology, School of Dentistry, Augusta University, Augusta, GA 30912, United States
| | - Nada H Eisa
- Georgia Cancer Center, Augusta University, Augusta, GA 30912, United States; Department of Biochemistry, Faculty of Pharmacy, Mansoura University, Mansoura, 35516, Egypt
| | - Dmitry Kondrikov
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC 29403, United States; Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC 29403, United States
| | - Khaled A Hussein
- Department of Surgery and Medicine, National Research Centre, Cairo, Egypt
| | - Alexandra Aguilar-Pérez
- Department of Anatomy and Cell Biology, Indiana University School of Medicine in Indianapolis, IN, United States; Department of Cellular and Molecular Biology, School of Medicine, Universidad Central del Caribe, Bayamon, 00956, Puerto Rico; Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA 30912, United States
| | - Samuel Herberg
- Departments of Ophthalmology & Cell and Dev. Bio., SUNY Upstate Medical University, Syracuse, NY 13210, United States
| | | | - Sadanand Fulzele
- Department of Orthopaedic Surgery, Medical College of Georgia, Augusta University, Augusta, GA 30912, United States; Center for Healthy Aging, Medical College of Georgia, Augusta University, Augusta, GA, 30912, United States
| | - Mark W Hamrick
- Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA 30912, United States; Department of Orthopaedic Surgery, Medical College of Georgia, Augusta University, Augusta, GA 30912, United States; Center for Healthy Aging, Medical College of Georgia, Augusta University, Augusta, GA, 30912, United States
| | - Meghan E McGee-Lawrence
- Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA 30912, United States; Department of Orthopaedic Surgery, Medical College of Georgia, Augusta University, Augusta, GA 30912, United States; Center for Healthy Aging, Medical College of Georgia, Augusta University, Augusta, GA, 30912, United States
| | - Carlos M Isales
- Department of Orthopaedic Surgery, Medical College of Georgia, Augusta University, Augusta, GA 30912, United States; Center for Healthy Aging, Medical College of Georgia, Augusta University, Augusta, GA, 30912, United States; Division of Endocrinology, Diabetes and Metabolism, Medical College of Georgia, Augusta University, Augusta, GA 30912, United States
| | - Brian F Volkman
- Biochemistry Department, Medical College of Wisconsin, Milwaukee, WI 53226, United States
| | - William D Hill
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC 29403, United States; Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC 29403, United States; Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA 30912, United States; Department of Orthopaedic Surgery, Medical College of Georgia, Augusta University, Augusta, GA 30912, United States; Center for Healthy Aging, Medical College of Georgia, Augusta University, Augusta, GA, 30912, United States.
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