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Heggli I, Mengis T, Laux C, Opitz L, Herger N, Menghini D, Schuepbach R, Farshad-Amacker N, Brunner F, Fields A, Farshad M, Distler O, Dudli S. Low back pain patients with Modic type 1 changes exhibit distinct bacterial and non-bacterial subtypes. Osteoarthr Cartil Open 2024; 6:100434. [PMID: 38322145 PMCID: PMC10844677 DOI: 10.1016/j.ocarto.2024.100434] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 12/13/2023] [Accepted: 01/08/2024] [Indexed: 02/08/2024] Open
Abstract
Objectives Modic type 1 changes (MC1) are vertebral endplate bone marrow (BM) lesions observed on magnetic resonance images in sub-populations of chronic low back pain (CLBP) patients. The etiopathogenesis remains unknown and treatments that modify the underlying pathomechanisms do not exist. We hypothesized that two biological MC1 subtypes exist: a bacterial and a non-bacterial. This would have important implications for developing treatments targeting the underlying pathomechanisms. Methods Intervertebral disc (IVD) samples adjacent to MC1 (n = 34) and control (n = 11) vertebrae were collected from patients undergoing spinal fusion. Cutibacterium acnes (C.acnes) genome copy numbers (GCNs) were quantified in IVD tissues with 16S qPCR, transcriptomic signatures and cytokine profiles were determined in MC1 and control BM by RNA sequencing and immunoassay. Finally, we assessed if C.acnes GCNs are associated with blood plasma cytokines. Results IVD tissues from control levels had <870 C.acnes GCNs/gram IVD. MC1-adjacent IVDs had either "low" (<870) or "high" (>870) C.acnes GCNs. MC1 patients with "high" C.acnes GCNs had upregulated innate immune cell signatures (neutrophil, macrophage/monocyte) and pro-inflammatory cytokines related to neutrophil and macrophage/monocyte function in the BM, consistent with a host defense against bacterium. MC1 patients with "low" C.acnes GCNs had increased adaptive immune cell signatures (T-and B-cell) in the BM and elevated IL-13 blood plasma levels. Conclusion Our study provides the first evidence for the existence of bacterial (C.acnes "high") and non-bacterial (C.acnes "low") subtypes in MC1 patients with CLBP. This supports the need for different treatment strategies.
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Affiliation(s)
- I. Heggli
- Center of Experimental Rheumatology, Department of Rheumatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
- Department of Physical Medicine and Rheumatology, Balgrist University Hospital, Balgrist Campus, University of Zurich, Zurich, Switzerland
| | - T. Mengis
- Center of Experimental Rheumatology, Department of Rheumatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
- Department of Physical Medicine and Rheumatology, Balgrist University Hospital, Balgrist Campus, University of Zurich, Zurich, Switzerland
| | - C.J. Laux
- Department of Orthopedics, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
| | - L. Opitz
- Functional Genomics Center Zurich, University and ETH Zurich, Zurich, Zurich, Switzerland
| | - N. Herger
- Center of Experimental Rheumatology, Department of Rheumatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
- Department of Physical Medicine and Rheumatology, Balgrist University Hospital, Balgrist Campus, University of Zurich, Zurich, Switzerland
| | - D. Menghini
- Center of Experimental Rheumatology, Department of Rheumatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
- Department of Physical Medicine and Rheumatology, Balgrist University Hospital, Balgrist Campus, University of Zurich, Zurich, Switzerland
| | - R. Schuepbach
- Unit of Clinical and Applied Research, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
| | - N.A. Farshad-Amacker
- Department of Radiology, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
| | - F. Brunner
- Department of Physical Medicine and Rheumatology, Balgrist University Hospital, Balgrist Campus, University of Zurich, Zurich, Switzerland
| | - A.J. Fields
- Department of Orthopaedic Surgery, University of California San Francisco, San Francisco, CA, USA
| | - M. Farshad
- Department of Orthopedics, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
| | - O. Distler
- Center of Experimental Rheumatology, Department of Rheumatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
- Department of Physical Medicine and Rheumatology, Balgrist University Hospital, Balgrist Campus, University of Zurich, Zurich, Switzerland
| | - S. Dudli
- Center of Experimental Rheumatology, Department of Rheumatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
- Department of Physical Medicine and Rheumatology, Balgrist University Hospital, Balgrist Campus, University of Zurich, Zurich, Switzerland
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Heggli I, Blache U, Herger N, Mengis T, Jaeger PK, Schuepbach R, Farshad-Amacker N, Brunner F, Snedeker JG, Farshad M, Distler O, Dudli S. FGF2 overrides key pro-fibrotic features of bone marrow stromal cells isolated from Modic type 1 change patients. Eur Cell Mater 2022; 44:101-114. [PMID: 36254571 DOI: 10.22203/ecm.v044a07] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Extensive extracellular matrix production and increased cell-matrix adhesion by bone marrow stromal cells (BMSCs) are hallmarks of fibrotic alterations in the vertebral bone marrow known as Modic type 1 changes (MC1). MC1 are associated with non-specific chronic low-back pain. To identify treatment targets for MC1, in vitro studies using patient BMSCs are important to reveal pathological mechanisms. For the culture of BMSCs, fibroblast growth factor 2 (FGF2) is widely used. However, FGF2 has been shown to suppress matrix synthesis in various stromal cell populations. The aim of the present study was to investigate whether FGF2 affected the in vitro study of the fibrotic pathomechanisms of MC1-derived BMSCs. Transcriptomic changes and changes in cell-matrix adhesion of MC1-derived BMSCs were compared to intra-patient control BMSCs in response to FGF2. RNA sequencing and quantitative real-time polymerase chain reaction revealed that pro-fibrotic genes and pathways were not detectable in MC1-derived BMSCs when cultured in the presence of FGF2. In addition, significantly increased cell-matrix adhesion of MC1-derived BMSCs was abolished in the presence of FGF2. In conclusion, the data demonstrated that FGF2 overrides key pro-fibrotic features of MC1 BMSCs in vitro. Usage of FGF2-supplemented media in studies of fibrotic mechanisms should be critically evaluated as it could override normally dominant biological and biophysical cues.
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Affiliation(s)
- I Heggli
- Balgrist Campus AG, Lengghalde 5, 8008 Zurich,
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Heggli I, Epprecht S, Juengel A, Schuepbach R, Farshad-Amacker N, German C, Mengis T, Herger N, Straumann L, Baumgartner S, Betz M, Spirig JM, Wanivenhaus F, Ulrich N, Bellut D, Brunner F, Farshad M, Distler O, Dudli S. Pro-fibrotic phenotype of bone marrow stromal cells in Modic type 1 changes. Eur Cell Mater 2021; 41:648-667. [PMID: 34101158 DOI: 10.22203/ecm.v041a42] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Modic type 1 changes (MC1) are painful vertebral bone marrow lesions frequently found in patients suffering from chronic low-back pain. Marrow fibrosis is a hallmark of MC1. Bone marrow stromal cells (BMSCs) are key players in other fibrotic bone marrow pathologies, yet their role in MC1 is unknown. The present study aimed to characterise MC1 BMSCs and hypothesised a pro-fibrotic role of BMSCs in MC1. BMSCs were isolated from patients undergoing lumbar spinal fusion from MC1 and adjacent control vertebrae. Frequency of colony-forming unit fibroblast (CFU-F), expression of stem cell surface markers, differentiation capacity, transcriptome, matrix adhesion, cell contractility as well as expression of pro-collagen type I alpha 1, α-smooth muscle actin, integrins and focal adhesion kinase (FAK) were compared. More CFU-F and increased expression of C-X-C-motif-chemokine 12 were found in MC1 BMSCs, possibly indicating overrepresentation of a perisinusoidal BMSC population. RNA sequencing analysis showed enrichment in extracellular matrix proteins and fibrosis-related signalling genes. Increases in pro-collagen type I alpha 1 expression, cell adhesion, cell contractility and phosphorylation of FAK provided further evidence for their pro-fibrotic phenotype. Moreover, a leptin receptor high expressing (LEPRhigh) BMSC population was identified that differentiated under transforming growth factor beta 1 stimulation into myofibroblasts in MC1 but not in control BMSCs. In conclusion, pro-fibrotic changes in MC1 BMSCs and a LEPRhigh MC1 BMSC subpopulation susceptible to myofibroblast differentiation were found. Fibrosis is a hallmark of MC1 and a potential therapeutic target. A causal link between the pro-fibrotic phenotype and clinical characteristics needs to be demonstrated.
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Affiliation(s)
- I Heggli
- Centre of Experimental Rheumatology, Balgrist Campus AG, Lengghalde 5, 8008 Zurich,
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Heggli I, Schüpbach R, Herger N, Schweizer TA, Juengel A, Farshad-Amacker N, Betz M, Spirig JM, Wanivenhaus F, Ulrich NH, Brunner F, Zinkernagel AS, Farshad M, Distler O, Dudli S. OP0083 INFECTIOUS AND AUTOINFLAMMATORY MODIC TYPE 1 CHANGES HAVE DIFFERENT PATHOMECHANISMS. Ann Rheum Dis 2021. [DOI: 10.1136/annrheumdis-2021-eular.825] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Background:Modic type 1 changes (MC1) are vertebral bone marrow (BM) edema that associate with non-specific low back pain (LBP). Two etiologies have been described. In the infectious etiology the anaerobic aerotolerant Cutibacterium acnes (C. acnes) invades damaged intervertebral discs (IVDs) resulting in disc infection and endplate damage, which leads to the evocation of an immune response. In the autoinflammatory etiology disc and endplate damage lead to the exposure of immune privileged disc cells and matrix to leukocytes, thereby evoking an immune response in the BM. Different etiologies require different treatment strategies. However, it is unknown if etiology-specific pathological mechanisms exist.Objectives:The aim of this study was to identify etiology-specific dysregulated pathways of MC1 and to perform in-depth analysis of immune cell populations of the autoinflammatory etiology.Methods:BM aspirates and biopsies were obtained from LBP patients with MC1 undergoing spinal fusion. Aspirates/biopsies were taken prior screw insertion through the pedicle screw trajectory. From each patient, a MC1 and an intra-patient control aspiration/biopsy from the adjacent vertebral level was taken. If C. acnes in IVDs adjacent to MC1 were detected by anaerobic bacterial culture, patients were assigned to the infectious, otherwise to the autoinflammatory etiology.Total RNA was isolated from aspirates and sequenced (Novaseq) (infectious n=3 + 3, autoinflammatory n=5 + 5). Genes were considered as differentially expressed (DEG) if p-value < 0.01 and log2fc > ± 0.5. Gene ontology (GO) enrichment was performed in R (GOseq), gene set enrichment analysis (GSEA) with GSEA software.Changes in cell populations of the autoinflammatory etiology were analyzed with single cell RNA sequencing (scRNAseq): Control and MC1 biopsies (n=1 + 1) were digested, CD45+CD66b- mononuclear cells isolated with fluorescence activated cell sorting (FACS), and 10000 cells were sequenced (10x Genomics). Seurat R toolkit was used for quality-control, clustering, and differential expression analysis.Transcriptomic changes (n=5 + 5) of CD45+CD66b+ neutrophils isolated with flow cytometry from aspirates were analyzed as for total bulk RNAseq. Neutrophil activation (n=3 + 3) was measured as CD66b+ expression with flow cytometry. CD66bhigh and CD66blow fractions in MC1 and control neutrophils were compared with paired t-test.Results:Comparing MC1 to control in total bulk RNAseq, 204 DEG in the autoinflammatory and 444 DEG in the infectious etiology were identified with only 67 shared genes (Fig. 1a). GO enrichment revealed “T-cell activation” (p = 2.50E-03) in the autoinflammatory and “complement activation, classical pathway” (p=1.1E-25) in the infectious etiology as top enriched upregulated biological processes (BP) (Fig 1b). ScRNAseq of autoinflammatory MC1 showed an overrepresentation of T-cells (p= 1.00E-34, OR=1.54) and myelocytes (neutrophil progenitor cells) (p=4.00E-05, OR=2.27) indicating an increased demand of these cells (Fig. 1c). Bulk RNAseq analysis of neutrophils from the autoinflammatory etiology revealed an activated, pro-inflammatory phenotype (Fig 1d), which was confirmed with more CD66bhigh neutrophils in MC1 (+11.13 ± 2.71%, p=0.02) (Fig. 1e).Figure 1.(a) Venn diagram of DEG from total bulk RNAseq (b) Top enriched upregulated BP of autoinflammatory (left) and infectious (right) etiology (c) Cell clustering of autoinflammatory MC1 BM (d) Enrichment of “inflammatory response” gene set in autoinflammatory MC1 neutrophils (e) Representative histogram of CD66b+ expression in MC1 and control neutrophils.Conclusion:Autoinflammatory and infectious etiologies of MC1 have different pathological mechanisms. T-cell and neutrophil activation seem to be important in the autoinflammatory etiology. This has clinical implication as it could be explored for diagnostic approaches to distinguish the two MC1 etiologies and supports developing targeted treatments for both etiologies.Disclosure of Interests:None declared
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Stroeve S, Dudli S, Kolm I, Heggli I, Herger N, Catanzaro S, Schweizer A, Calcagni M, Distler O, Brunner F, Juengel A. OP0085 ALTERED EXPRESSION OF NEUROTROPHINS AND THEIR RECEPTORS IN THE SKIN OF PATIENT WITH COMPLEX REGIONAL PAIN SYNDROME (CRPS). Ann Rheum Dis 2021. [DOI: 10.1136/annrheumdis-2021-eular.830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Background:Complex regional pain syndrome (CRPS) is a rare painful condition that usually appears after trauma or surgery of the extremities. Symptoms include pain, sensory, sudomotor and vasomotor disturbances, trophic changes and impaired motor function. The course varies from mild to chronic disease with a high impact on daily functioning and quality of life. In skin tissue, sustained inflammatory, fibrotic processes together with reduced epidermal nerve fibers are reported. Neurotrophins and their receptors are mediators in cell-to-cell communication and key mediators of pain signalingObjectives:The aim of this study was to identify differential expression of neurotrophins and their receptors in the skin and skin fibroblasts of patients with CRPSMethods:Healthy controls (HC) and patients with acute CRPS with symptoms for less than 6 months fulfilling the Budapest criteria were recruited. Pain scores were evaluated by numeric rating scale (0=no pain, 100=maximal) and body perception was assessed using the Bath Body Perception Disturbance Scale (BBPDS) (0=no perception disturbance, 57=maximal perception disturbance).Skin biopsies of the affected and/or non-affected side were taken. Immunohistochemistry on formalin-fixed, paraffin-embedded skin tissue slides was used to show NT3 expression in skin tissues. Blinded analysis was done by an experienced dermato-pathologist determined staining graduated by 0= none, 1= sparse, 2=moderate, 3= dense.Skin fibroblast were isolated from skin biopsies by outgrowth cultures (CRPS, affected side, n=6 and HC, n=5). Cells (passage 3-6) were starved and subsequently stimulated with TNFα (10 ng/ml) or TGFβ (10 ng/ml) for 24 h to mimic active disease and total RNA was isolated by miRNeasy kit. Gene expression of neurotrophins (NGF, BDNF, and NT3) and neurotrophin receptors (NGFR, TrkA, TrkB and TrkC) was measured by quantitative real time PCR and quantified using the ΔΔCq method with GAPDH as a reference gene. ELISA was used to analyze NT3 protein expression in cell culture supernatants.Results:In 5 of 9 patients with CRPS immunohistological staining of NT3 showed an higher expression (from low to moderate) in the affected side versus the non-affected side. In 4 of 9 patients the expression of NT3 was high in the non-affected side (moderate/dense) and stayed high in the affected side.Of interest, the patients with increasing expression of NT3 in the affected side showed increased pain scores (max pain 80+/-10.95, n=5 versus 48.16+/-18.16, n=4, p=0.059 and changed body perception 26.8+/-8.68 n=5 versus 6.5+/-3.91, n=4, p=0.016).Isolated skin fibroblasts from the affected side of patients with CRPS compared to healthy skin fibroblasts showed higher basal gene expression of NT3 (log2 fold-change= 1.9 +/- 0.4, p= 0.005) and NGFR (log2 fold-change= 3.6 +/- 2.1, p=0.014). TNFα stimulated CRPS skin fibroblasts showed higher expression for NT3 (log2 fold-change= 2.1 +/- 1.2, p=0.002) compared to HC. TGFb stimulated skin fibroblasts of patients with CRPS showed higher expression of NT3 (log2 fold-change= 1.4+/-0.8, p=0.019), NGFR (log2 fold-change= 2.6 +/- 1.8, p=0.036) and TrkC (log2 fold-change= 2.3 +/- 1.8, p=0.032) compared to HC.On protein level, NT3 showed a tendency of upregulation in unstimulated fibroblasts from CRPS patients comparing to HC (CRPS mean= 8.0 +/- 2.2 pg/ml, HC mean= 6.3 +/- 1.8 pg/ml, p=0.25). After TNFα stimulation, protein level of NT3 was significantly higher in CRPS skin fibroblasts (CRPS mean= 10.6 +/- 2.4 pg/ml, HC mean= 4.8 +/- 1.3 pg/ml, p=0.004).Conclusion:These data indicate a new role of skin fibroblasts in CRPS. Differential basal and stimulated expression of NT3, the receptor for NT3 (TrkC) and NGFR, the common receptor for all neurotrophins, indicates deregulated communication of fibroblasts with the sensory nerve fibers in CRPS. This might contribute to the dysregulated healing process and sustained pain.Disclosure of Interests:Sanne Stroeve: None declared, Stefan Dudli: None declared, Isabel Kolm: None declared, Irina Heggli: None declared, Nick Herger: None declared, Sabrina Catanzaro: None declared, Andreas Schweizer: None declared, Maurizio Calcagni Speakers bureau: Arthrex, Consultant of: Medartis, Arthrex, SilkBiomaterials, Grant/research support from: Medartis, Oliver Distler: None declared, Florian Brunner: None declared, Astrid Juengel: None declared
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Storelvmo T, Boos WR, Herger N. Cirrus cloud seeding: a climate engineering mechanism with reduced side effects? Philos Trans A Math Phys Eng Sci 2014; 372:rsta.2014.0116. [PMID: 25404685 DOI: 10.1098/rsta.2014.0116] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Climate engineering, the intentional alteration of Earth's climate, is a multifaceted and controversial topic. Numerous climate engineering mechanisms (CEMs) have been proposed, and the efficacies and potential undesired consequences of some of them have been studied in the safe environments of numerical models. Here, we present a global modelling study of a so far understudied CEM, namely the seeding of cirrus clouds to reduce their lifetimes in the upper troposphere, and hence their greenhouse effect. Different from most CEMs, the intention of cirrus seeding is not to reduce the amount of solar radiation reaching Earth's surface. This particular CEM rather targets the greenhouse effect, by reducing the trapping of infrared radiation by high clouds. This avoids some of the caveats that have been identified for solar radiation management, for example, the delayed recovery of stratospheric ozone or drastic changes to Earth's hydrological cycle. We find that seeding of mid- and high-latitude cirrus clouds has the potential to cool the planet by about 1.4 K, and that this cooling is accompanied by only a modest reduction in rainfall. Intriguingly, seeding of the 15% of the globe with the highest solar noon zenith angles at any given time yields the same global mean cooling as a seeding strategy that involves 45% of the globe. In either case, the cooling is strongest at high latitudes, and could therefore serve to prevent Arctic sea ice loss. With the caveat that there are still significant uncertainties associated with ice nucleation in cirrus clouds and its representation in climate models, cirrus seeding appears to represent a powerful CEM with reduced side effects.
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Affiliation(s)
- T Storelvmo
- Department of Geology and Geophysics, Yale University, 210 Whitney Avenue, New Haven, CT 06511, USA
| | - W R Boos
- Department of Geology and Geophysics, Yale University, 210 Whitney Avenue, New Haven, CT 06511, USA
| | - N Herger
- Institute for Atmospheric and Climate Science, ETH-Zurich, Zurich, Switzerland
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