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Erbacher C, Britz S, Dinkel P, Klein T, Sauer M, Stigloher C, Üçeyler N. Interaction of human keratinocytes and nerve fiber terminals at the neuro-cutaneous unit. eLife 2024; 13:e77761. [PMID: 38225894 PMCID: PMC10791129 DOI: 10.7554/elife.77761] [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: 02/09/2022] [Accepted: 12/19/2023] [Indexed: 01/17/2024] Open
Abstract
Traditionally, peripheral sensory neurons are assumed as the exclusive transducers of external stimuli. Current research moves epidermal keratinocytes into focus as sensors and transmitters of nociceptive and non-nociceptive sensations, tightly interacting with intraepidermal nerve fibers at the neuro-cutaneous unit. In animal models, epidermal cells establish close contacts and ensheath sensory neurites. However, ultrastructural morphological and mechanistic data examining the human keratinocyte-nerve fiber interface are sparse. We investigated this exact interface in human skin applying super-resolution array tomography, expansion microscopy, and structured illumination microscopy. We show keratinocyte ensheathment of afferents and adjacent connexin 43 contacts in native skin and have applied a pipeline based on expansion microscopy to quantify these parameter in skin sections of healthy participants versus patients with small fiber neuropathy. We further derived a fully human co-culture system, visualizing ensheathment and connexin 43 plaques in vitro. Unraveling human intraepidermal nerve fiber ensheathment and potential interaction sites advances research at the neuro-cutaneous unit. These findings are crucial on the way to decipher the mechanisms of cutaneous nociception.
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Affiliation(s)
| | - Sebastian Britz
- Imaging Core Facility, Biocenter, University of WürzburgWürzburgGermany
| | - Philine Dinkel
- Department of Neurology, University Hospital of WürzburgWürzburgGermany
| | - Thomas Klein
- Department of Neurology, University Hospital of WürzburgWürzburgGermany
| | - Markus Sauer
- Department of Biotechnology and Biophysics, University of WürzburgWürzburgGermany
| | | | - Nurcan Üçeyler
- Department of Neurology, University Hospital of WürzburgWürzburgGermany
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Shin SM, Baek EJ, Oh DY, Kim KH, Kim KJ, Park EJ. Functional validation of co-culture model of human keratinocytes and neuronal cell line for sensitive skin by using transient receptor potential channel vanilloid subfamily member 1 antagonist. Skin Res Technol 2023; 29:e13275. [PMID: 36704884 PMCID: PMC9838752 DOI: 10.1111/srt.13275] [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: 08/22/2022] [Accepted: 12/23/2022] [Indexed: 01/11/2023]
Abstract
BACKGROUND Sensitive skin is a subjective cutaneous hyper-reactivity that occurs in response to various innocuous stimuli. Keratinocytes have recently been shown to participate in sensory transduction by releasing many neuroactive molecules that bind to intra-epidermal free nerve endings and modulate nociception. In the literature, the characterization of these interactions has been based on the co-culture of keratinocyte and mammalian-origin neuronal cell lines. In this study, we established an in vitro model based on a co-culture of primary human keratinocytes and differentiated SH-SY5Y cells, a human neuronal cell line. METHODS Human epidermal keratinocytes and SH-SY5Y cells were monocultured and co-cultured. Changes in calcium influx, substance P, inflammatory cytokines, and neuropeptides between the monoculture and co-culture groups treated with capsaicin only and capsaicin with transient receptor potential channel vanilloid subfamily member 1 (TRPV1) antagonist, trans-4-tert-butylcyclohexanol (TTBC), together. In addition, the difference in stinging sensation was evaluated by applying it to the volunteers. RESULTS When SH-SY5Y cells were co-cultured with keratinocytes, they had no significant effect on axonal development. Substance P was also released after capsaicin treatment and reduced by TTBC under co-culture conditions. Moreover, the expression of inflammatory cytokines and neuropeptides was significantly increased in co-cultured keratinocytes compared to that under monoculture conditions. In addition, the stinging sensation was significantly induced after the application of capsaicin in vivo and was relieved after the application of the TRPV1 antagonist. CONCLUSION We demonstrated that the novel co-culture model is functionally valid through capsaicin and TRPV1 antagonist. We also confirmed that TTBC could be used for the treatment of sensitive skin through a co-culture model and in vivo tests. This co-culture model of keratinocytes and SH-SY5Y cells may be useful in vitro alternatives for studying the close communication between keratinocytes and neuronal cells and for screening therapeutic drugs for sensitive skin.
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Affiliation(s)
- Sun Mee Shin
- Department of Dermatology, Hallym Institute for Translational Medicine, Anyang, Korea
| | - Eun Joo Baek
- Department of Dermatology, Hallym University Sacred Heart Hospital, Anyang, Korea
| | - Dong Yeol Oh
- Department of Dermatology, Hallym University Sacred Heart Hospital, Anyang, Korea
| | - Kwang Ho Kim
- Department of Dermatology, Hallym University Sacred Heart Hospital, Anyang, Korea
| | - Kwang Joong Kim
- Department of Dermatology, Hallym University Sacred Heart Hospital, Anyang, Korea
| | - Eun Joo Park
- Department of Dermatology, Hallym University Sacred Heart Hospital, Anyang, Korea
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Cutaneous innervation in impaired diabetic wound healing. Transl Res 2021; 236:87-108. [PMID: 34029747 PMCID: PMC8380642 DOI: 10.1016/j.trsl.2021.05.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/09/2021] [Accepted: 05/11/2021] [Indexed: 12/11/2022]
Abstract
Type 2 diabetes is associated with several potential comorbidities, among them impaired wound healing, chronic ulcerations, and the requirement for lower extremity amputation. Disease-associated abnormal cellular responses, infection, immunological and microvascular dysfunction, and peripheral neuropathy are implicated in the pathogenesis of the wound healing impairment and the diabetic foot ulcer. The skin houses a dense network of sensory nerve afferents and nerve-derived modulators, which communicate with epidermal keratinocytes and dermal fibroblasts bidirectionally to effect normal wound healing after trauma. However, the mechanisms through which cutaneous innervation modulates wound healing are poorly understood, especially in humans. Better understanding of these mechanisms may provide the basis for targeted treatments for chronic diabetic wounds. This review provides an overview of wound healing pathophysiology with a focus on neural involvement in normal and diabetic wound healing, as well as future therapeutic perspectives to address the unmet needs of diabetic patients with chronic wounds.
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Differential impact of keratinocytes and fibroblasts on nociceptor degeneration and sensitization in small fiber neuropathy. Pain 2021; 162:1262-1272. [PMID: 33196576 DOI: 10.1097/j.pain.0000000000002122] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 10/20/2020] [Indexed: 02/07/2023]
Abstract
ABSTRACT Peripheral denervation and pain are hallmarks of small fiber neuropathy (SFN). We investigated the contribution of skin cells on nociceptor degeneration and sensitization. We recruited 56 patients with SFN and 31 healthy controls and collected skin punch biopsies for immunohistochemical and immunocytochemical analysis of netrin-1 (NTN1) and proinflammatory and anti-inflammatory cytokine expression patterns. We further applied coculture systems with murine dorsal root ganglion (DRG) neurons for skin cell-nerve interaction studies and patch-clamp analysis. Human keratinocytes attract murine DRG neuron neurites, and the gene expression of the axon guidance cue NTN1 is higher in keratinocytes of patients with SFN than in controls. NTN1 slows and reduces murine sensory neurite outgrowth in vitro, but does not alter keratinocyte cytokine expression. In the naive state, keratinocytes of patients with SFN show a higher expression of transforming growth factor-β1 (P < 0.05), while fibroblasts display higher expression of the algesic cytokines interleukin (IL)-6 (P < 0.01) and IL-8 (P < 0.05). IL-6 incubation of murine DRG neurons leads to an increase in action potential firing rates compared with baseline (P < 0.01). Our data provide evidence for a differential effect of keratinocytes and fibroblasts on nociceptor degeneration and sensitization in SFN compared with healthy controls and further supports the concept of cutaneous nociception.
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Ho HKY, Bigliardi PL, Stelmashenko O, Ramasamy S, Postlethwaite M, Bigliardi-Qi M. Functionally expressed bitter taste receptor TAS2R14 in human epidermal keratinocytes serves as a chemosensory receptor. Exp Dermatol 2021; 30:216-225. [PMID: 33253444 DOI: 10.1111/exd.14250] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 10/30/2020] [Accepted: 11/23/2020] [Indexed: 01/23/2023]
Abstract
Traditionally, it is theorized that skin sensation is initiated when cutaneous sensory afferents and Merkel cells receive sensory stimuli, while epidermal keratinocytes were deemed to have no role. However, mounting evidence has shown that keratinocytes can initiate skin sensation by receiving sensory stimuli and transmitting sensory information to sensory afferents. Knowledge regarding the mechanisms by which keratinocytes receive exogenous stimuli is limited, with TRP channels and olfactory receptors having been proposed to serve as receptors for exogenous stimuli in keratinocytes. Recently, expression analyses have demonstrated the expression of multiple TAS2R genes in human skin. TAS2Rs are chemosensory GPCRs employed by taste cells to detect bitter-tasting substances. However, only subtypes TAS2R1 and TAS2R38 have been characterized in epidermal keratinocytes. We present evidence suggesting that subtype TAS2R14 is functionally expressed in epidermal keratinocytes. TAS2R14 transcripts and protein were detected in primary and N/TERT-1 keratinocytes. Additionally, keratinocytes responded to α-thujone, a TAS2R14 ligand, with an increase in intracellular free Ca2+ concentration. The tastant-evoked Ca2+ signals were found to be mediated by wild-type TAS2R14 and heterotrimeric G proteins. We conclude that TAS2R14 serves as a chemosensory receptor in epidermal keratinocytes and hypothesize that it enables the cells to recognize potentially harmful chemical substances.
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Affiliation(s)
- Hilary Kung-Yu Ho
- Agency for Science, Technology and Research, Institute of Medical Biology, Singapore, Singapore
| | - Paul Lorenz Bigliardi
- Department of Dermatology, University of Minnesota, Twin Cities, Minneapolis, MN, USA
| | - Olga Stelmashenko
- Agency for Science, Technology and Research, Institute of Medical Biology, Singapore, Singapore
| | - Srinivas Ramasamy
- Agency for Science, Technology and Research, Skin Research Institute Singapore, Singapore, Singapore
| | - Michael Postlethwaite
- Agency for Science, Technology and Research, Institute of Medical Biology, Singapore, Singapore
| | - Mei Bigliardi-Qi
- Department of Dermatology, University of Minnesota, Twin Cities, Minneapolis, MN, USA
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Kreß L, Üçeyler N. [Pain prevention: what is in the pipeline?]. Schmerz 2020; 35:53-58. [PMID: 33185763 DOI: 10.1007/s00482-020-00515-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 10/07/2020] [Accepted: 10/09/2020] [Indexed: 10/23/2022]
Abstract
Approximately 10% of the German population report chronic pain that has at least a moderate influence on everyday life. For instance, patients in Germany often experience an oversupply of diagnostics and therapy when suffering from mild back pain, while the care of patients with severe, chronic pain remains insufficient. Multimodal and interdisciplinary therapies are generally too seldomly used. Potentially preventive procedures are insufficiently investigated and used in current clinical practice and little is known about the mechanisms underlying chronification processes. In Germany, pain is still largely neglected in current clinical and basic science, as well as research funding. Furthermore, existing projects are often insufficiently connected with each other, thereby missing the unique opportunity of building synergies. To improve medical pain care and to enable participation in activities of daily life with the maximum radius, interdisciplinary clinical programs and cross-linking of basic and clinical research is necessary. The main objectives are to: (1) Strengthen basic research to investigate the underlying mechanisms of pain development and maintenance as well as of chronification processes; (2) improve patient care by adequate application of diagnostic, therapeutic, and preventive procedures; (3) consolidate interdisciplinarity in pain research and patient care; (4) maintain participation of patients in social and in everyday life; and (5) achieve and maintain high quality standards in pain patient care. The following article provides an overview of the measures and advances currently being taken in pain research in Germany to close the above-mentioned gaps. The focus lies on current and future developments in the field of pain prevention.
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Affiliation(s)
- Luisa Kreß
- Neurologische Klinik und Poliklinik, Universitätsklinikum Würzburg, Josef-Schneider-Str. 11, 97080, Würzburg, Deutschland
| | - Nurcan Üçeyler
- Neurologische Klinik und Poliklinik, Universitätsklinikum Würzburg, Josef-Schneider-Str. 11, 97080, Würzburg, Deutschland.
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Karl F, Wußmann M, Kreß L, Malzacher T, Fey P, Groeber-Becker F, Üçeyler N. Patient-derived in vitro skin models for investigation of small fiber pathology. Ann Clin Transl Neurol 2019; 6:1797-1806. [PMID: 31464071 PMCID: PMC6764636 DOI: 10.1002/acn3.50871] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 07/24/2019] [Accepted: 07/30/2019] [Indexed: 12/24/2022] Open
Abstract
Objective To establish individually expandable primary fibroblast and keratinocyte cultures from 3‐mm skin punch biopsies for patient‐derived in vitro skin models to investigate of small fiber pathology. Methods We obtained 6‐mm skin punch biopsies from the calf of two patients with small fiber neuropathy (SFN) and two healthy controls. One half (3 mm) was used for diagnostic intraepidermal nerve fiber density (IENFD). From the second half, we isolated and cultured fibroblasts and keratinocytes. Cells were used to generate patient‐derived full‐thickness three‐dimensional (3D) skin models containing a dermal and epidermal component. Cells and skin models were characterized morphologically, immunocyto‐ and ‐histochemically (vimentin, cytokeratin (CK)‐10, CK 14, ki67, collagen1, and procollagen), and by electrical impedance. Results Distal IENFD was reduced in the SFN patients (2 fibers/mm each), while IENFD was normal in the controls (8 fibers/mm, 7 fibers/mm). Two‐dimensional (2D) cultured skin cells showed normal morphology, adequate viability, and proliferation, and expressed cell‐specific markers without relevant difference between SFN patient and healthy control. Using 2D cultured fibroblasts and keratinocytes, we obtained subject‐derived 3D skin models. Morphology of the 3D model was analogous to the respective skin biopsy specimens. Both, the dermal and the epidermal layer carried cell‐specific markers and showed a homogenous expression of extracellular matrix proteins. Interpretation Our protocol allows the generation of disease‐specific 2D and 3D skin models, which can be used to investigate the cross‐talk between skin cells and sensory neurons in small fiber pathology.
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Affiliation(s)
- Franziska Karl
- Department of Neurology, University of Würzburg, Josef-Schneider-Str. 11, 97080, Würzburg, Germany
| | - Maximiliane Wußmann
- Translational Center Regenerative Therapies, Fraunhofer Institute for Silicate Research, Neunerplatz 2, 97082, Würzburg, Germany
| | - Luisa Kreß
- Department of Neurology, University of Würzburg, Josef-Schneider-Str. 11, 97080, Würzburg, Germany
| | - Tobias Malzacher
- Department of Neurology, University of Würzburg, Josef-Schneider-Str. 11, 97080, Würzburg, Germany
| | - Phillip Fey
- Translational Center Regenerative Therapies, Fraunhofer Institute for Silicate Research, Neunerplatz 2, 97082, Würzburg, Germany
| | - Florian Groeber-Becker
- Translational Center Regenerative Therapies, Fraunhofer Institute for Silicate Research, Neunerplatz 2, 97082, Würzburg, Germany.,Department of Tissue Engineering & Regenerative Medicine, University Hospital Würzburg, Röntgenring 11, 97070, Würzburg, Germany
| | - Nurcan Üçeyler
- Department of Neurology, University of Würzburg, Josef-Schneider-Str. 11, 97080, Würzburg, Germany
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Lebonvallet N, Laverdet B, Misery L, Desmoulière A, Girard D. New insights into the roles of myofibroblasts and innervation during skin healing and innovative therapies to improve scar innervation. Exp Dermatol 2018; 27:950-958. [DOI: 10.1111/exd.13681] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/26/2018] [Indexed: 12/11/2022]
Affiliation(s)
- Nicolas Lebonvallet
- Department of Dermatology and EA4685 “Laboratory Interactions Neurons-Keratinocytes”; Faculty of Medicine and Health Sciences; University of Western Brittany; Brest France
| | - Betty Laverdet
- Department of Physiology and EA6309 “Myelin Maintenance and Peripheral Neuropathies”; Faculty of Pharmacy; University of Limoges; Limoges France
| | - Laurent Misery
- Department of Dermatology and EA4685 “Laboratory Interactions Neurons-Keratinocytes”; Faculty of Medicine and Health Sciences; University of Western Brittany; Brest France
| | - Alexis Desmoulière
- Department of Physiology and EA6309 “Myelin Maintenance and Peripheral Neuropathies”; Faculty of Pharmacy; University of Limoges; Limoges France
| | - Dorothée Girard
- Department of Physiology and EA6309 “Myelin Maintenance and Peripheral Neuropathies”; Faculty of Pharmacy; University of Limoges; Limoges France
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Abstract
The process of recovery from skin wounding can be protracted and painful, and scarring may lead to weakness of the tissue, unpleasant sensations such as pain or itch, and unfavorable cosmetic outcomes. Moreover, some wounds simply fail to heal and become a chronic burden for the sufferer. Understanding the mechanisms underlying wound healing and the concomitant sensory disorders and how they might be manipulated for therapeutic benefit has attracted much interest in recent years, and here we discuss the latest developments in the field, focusing on the emergent roles of the peripheral opioid receptor (OPr) system.
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Affiliation(s)
- Mei Bigliardi-Qi
- Experimental Dermatology Group, Institute of Medical Biology, A*STAR, Singapore, Singapore, 138648.
| | - Paul Bigliardi
- NUH/NUS, National University Hospital/National University of Singapore, Singapore, Singapore, 119228
- Experimental Dermatology Group, Institute of Medical Biology, A*STAR, Singapore, Singapore, 138648
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Talagas M, Lebonvallet N, Leschiera R, Marcorelles P, Misery L. What about physical contacts between epidermal keratinocytes and sensory neurons? Exp Dermatol 2017; 27:9-13. [DOI: 10.1111/exd.13411] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/03/2017] [Indexed: 01/01/2023]
Affiliation(s)
- Matthieu Talagas
- Laboratory of Interactions Neurons Keratinocytes (EA4685); Faculty of Medicine and Health Sciences; University of Western Brittany; Brest France
- Department of Pathology; Brest University Hospital; Brest France
- IBSAM (Institut Brestois de Santé Agro Matière); University of Western Brittany; Brest France
| | - Nicolas Lebonvallet
- Laboratory of Interactions Neurons Keratinocytes (EA4685); Faculty of Medicine and Health Sciences; University of Western Brittany; Brest France
- IBSAM (Institut Brestois de Santé Agro Matière); University of Western Brittany; Brest France
| | - Raphael Leschiera
- Laboratory of Interactions Neurons Keratinocytes (EA4685); Faculty of Medicine and Health Sciences; University of Western Brittany; Brest France
- IBSAM (Institut Brestois de Santé Agro Matière); University of Western Brittany; Brest France
| | - Pascale Marcorelles
- Laboratory of Interactions Neurons Keratinocytes (EA4685); Faculty of Medicine and Health Sciences; University of Western Brittany; Brest France
- Department of Pathology; Brest University Hospital; Brest France
- IBSAM (Institut Brestois de Santé Agro Matière); University of Western Brittany; Brest France
| | - Laurent Misery
- Laboratory of Interactions Neurons Keratinocytes (EA4685); Faculty of Medicine and Health Sciences; University of Western Brittany; Brest France
- IBSAM (Institut Brestois de Santé Agro Matière); University of Western Brittany; Brest France
- Department of Dermatology; Brest University Hospital; Brest France
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