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Wareing N, Mills TW, Collum S, Wu M, Revercomb L, Girard R, Lyons M, Skaug B, Bi W, Ali MA, Koochak H, Flores AR, Yang Y, Zheng WJ, Swindell W, Assassi S, Karmouty-Quintana H. Deletion of adipocyte Sine Oculis Homeobox Homolog 1 prevents lipolysis and attenuates skin fibrosis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.22.595271. [PMID: 38826482 PMCID: PMC11142148 DOI: 10.1101/2024.05.22.595271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Background The cardinal feature of systemic sclerosis (SSc) is skin thickening and tightening. Targetable mechanisms for skin features remain elusive. Drugs successful in treating internal organ manifestations have failed efficacy in skin. Dermal white adipose tissue (DWAT) is amongst the understudied contributors to skin manifestations. This study proposes the role of sine oculis homeobox homolog 1 ( SIX1 ), a gene previously unrecognized as a contributor to dermal lipoatrophy characteristic of early skin fibrosis in SSc. Methods Skin gene expression of SIX1 was analyzed in the GENISOS and PRESS SSc cohorts. Correlation analysis was performed with Spearman rank analysis. Novel mouse models were developed using the Cre-loxp system to knock out Six1 in all cells and mature adipocytes. Subcutaneous bleomycin was used to model early DWAT atrophy and dermal fibrosis characteristic of SSc. Findings SIX1 was upregulated in SSc skin, the expression of which correlates with adipose-associated genes and molecular pathways. Genetic deletion of Six1 in all cells in mice challenged with bleomycin abrogated end-stage fibrotic gene expression and dermal adipocyte shrinkage. Adipocyte specific Six1 deletion was able to attenuate the early increase in skin thickness, a hallmark of experimental skin fibrosis. Further studies revealed a link between elevated SIX1 and increased expression of SERPINE1 and its protein PAI-1 which are known pro-fibrotic mediators. Interpretation This work identifies SIX1 as an early marker of skin fibrosis in SSc. We also demonstrate a causative role of Six1 in skin fibrosis by promoting adipocyte loss and show that deletion of Six1 in adipocytes has the potential of impacting early disease progression. Research in context Evidence before this study: Skin thickening and tightening are leading causes of morbidity in systemic sclerosis (SSc). The authors previously reported that the aberrantly expressed developmental transcription factor sine oculis homeobox homology 1 (SIX1) drives pulmonary fibrosis. However, the contribution of SIX1 to skin fibrosis and associated dermal fat loss remains unknown.Added value of this study: The role of dermal fat loss in skin fibrosis is not fully understood. Studies have shown that adipocytes can transition to mesenchymal cells promoting fibrosis, consistent with loss of the dermal white adipose layer. Our research provides insight into a novel molecular mechanism of lipodystrophy important for skin fibrosis in SSc. We identified the upregulation of SIX1 in adipocytes in skin from patients with SSc which was associated with the progression of skin fibrosis. We found elevated Six1 in mouse dermal adipocytes of early fibrotic skin. Ubiquitous and adipose-specific loss of Six1 decreased markers of experimental skin fibrosis in mice which recapitulate cardinal features of SSc dermal fibrosis. Increased SIX1 expression is linked with elevated levels of Serpine1 the gene that codes for the protein plasminogen activator inhibitor (PAI)-1. This is important since PAI-1 is a known pro-fibrotic agent in the skin that contributes to the deposition of extracellular matrix (ECM) products. Implications of all the available evidence: Fat atrophy may represent a targetable contributor to early systemic sclerosis manifestations. This is as it precedes skin fibrosis and the use of topical agent which are usually lipophilic can help us target dermal adipocytes. Our results show that SIX1 could be an important early marker for skin fibrosis in SSc that can also be targeted therapeutically.
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Jimenez SA, Piera-Velazquez S. Cellular Transdifferentiation: A Crucial Mechanism of Fibrosis in Systemic Sclerosis. Curr Rheumatol Rev 2024; 20:388-404. [PMID: 37921216 DOI: 10.2174/0115733971261932231025045400] [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: 05/12/2023] [Revised: 07/13/2023] [Accepted: 07/27/2023] [Indexed: 11/04/2023]
Abstract
Systemic Sclerosis (SSc) is a systemic autoimmune disease of unknown etiology with a highly complex pathogenesis that despite extensive investigation is not completely understood. The clinical and pathologic manifestations of the disease result from three distinct processes: 1) Severe and frequently progressive tissue fibrosis causing exaggerated and deleterious accumulation of interstitial collagens and other extracellular matrix molecules in the skin and various internal organs; 2) extensive fibroproliferative vascular lesions affecting small arteries and arterioles causing tissue ischemic alterations; and 3) cellular and humoral immunity abnormalities with the production of numerous autoantibodies, some with very high specificity for SSc. The fibrotic process in SSc is one of the main causes of disability and high mortality of the disease. Owing to its essentially universal presence and the severity of its clinical effects, the mechanisms involved in the development and progression of tissue fibrosis have been extensively investigated, however, despite intensive investigation, the precise molecular mechanisms have not been fully elucidated. Several recent studies have suggested that cellular transdifferentiation resulting in the phenotypic conversion of various cell types into activated myofibroblasts may be one important mechanism. Here, we review the potential role that cellular transdifferentiation may play in the development of severe and often progressive tissue fibrosis in SSc.
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Affiliation(s)
- Sergio A Jimenez
- Department of Dermatology and Cutaneous Biology, Jefferson Institute of Molecular Medicine and Scleroderma Center, Thomas Jefferson University, Philadelphia 19107, USA
| | - Sonsoles Piera-Velazquez
- Department of Dermatology and Cutaneous Biology, Jefferson Institute of Molecular Medicine and Scleroderma Center, Thomas Jefferson University, Philadelphia 19107, USA
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Niemczyk A, Waśkiel-Burnat A, Zaremba M, Czuwara J, Rudnicka L. The profile of adipokines associated with fibrosis and impaired microcirculation in systemic sclerosis. Adv Med Sci 2023; 68:298-305. [PMID: 37696138 DOI: 10.1016/j.advms.2023.09.001] [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: 02/06/2023] [Revised: 05/03/2023] [Accepted: 09/02/2023] [Indexed: 09/13/2023]
Abstract
PURPOSE Adipokines belong to a group of molecules mostly produced by adipose tissue. Abnormalities in the secretion of several adipokines have already implicated to play a pathogenic role in systemic sclerosis (SSc). However, the possible role of numerous molecules still needs to be clarified. The aim of the study was to determine whether the altered level of selected circulating adipokines might correlate with the intensity of fibrosis and vasculopathy in the course of SSc. MATERIALS AND METHODS Serum concentrations of chemerin, adipsin, retinol-binding protein 4, apelin, visfatin, omentin-1, and vaspin were determined with ELISA in the sera of patients with SSc (n = 55) and healthy controls (n = 25). RESULTS The serum concentration of adipsin (p = 0.03) and visfatin (p = 0.04) was significantly increased and the level of retinol-binding protein 4 (p = 0.03) was decreased in diffuse compared to limited cutaneous SSc. Moreover, serum adipsin level correlated positively with the intensity of skin fibrosis measured with the modified Rodnan skin score (r = 0.31, p = 0.02) and was significantly higher in patients with pulmonary arterial hypertension than in those without the condition (p = 0.03). The concentrations of adipsin (p = 0.01) and visfatin (p = 0.04) were significantly increased and the level of apelin (p = 0.02) was decreased in patients with active digital ulcerations compared to individuals without this complication. CONCLUSION Adipsin may be considered a pivotal protein in the development of both fibrosis and impaired microcirculation. Its abnormal concentration reflects the intensity of skin thickening and the presence of pulmonary arterial hypertension. Adipsin, visfatin, and apelin are adipose tissue-derived molecules associated with digital vasculopathy.
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Affiliation(s)
- Anna Niemczyk
- Department of Dermatology, Medical University of Warsaw, Warsaw, Poland.
| | | | - Michał Zaremba
- Department of Dermatology, Medical University of Warsaw, Warsaw, Poland
| | - Joanna Czuwara
- Department of Dermatology, Medical University of Warsaw, Warsaw, Poland
| | - Lidia Rudnicka
- Department of Dermatology, Medical University of Warsaw, Warsaw, Poland
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Jimenez SA, Piera-Velazquez S. Probable role of exosomes in the extension of fibrotic alterations from affected to normal cells in systemic sclerosis. Rheumatology (Oxford) 2023; 62:999-1008. [PMID: 35944210 PMCID: PMC9977136 DOI: 10.1093/rheumatology/keac451] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/14/2022] [Accepted: 08/02/2022] [Indexed: 11/13/2022] Open
Abstract
SSc is a systemic autoimmune disease of unknown etiology characterized by frequently progressive cutaneous and internal organ fibrosis causing severe disability, organ failure and high mortality. A remarkable feature of SSc is the extension of the fibrotic alterations to nonaffected tissues. The mechanisms involved in the extension of fibrosis have remained elusive. We propose that this process is mediated by exosome microvesicles released from SSc-affected cells that induce an activated profibrotic phenotype in normal or nonaffected cells. Exosomes are secreted microvesicles involved in an intercellular communication system. Exosomes can transfer their macromolecular content to distant target cells and induce paracrine effects in the recipient cells, changing their molecular pathways and gene expression. Confirmation of this hypothesis may identify the molecular mechanisms responsible for extension of the SSc fibrotic process from affected cells to nonaffected cells and may allow the development of novel therapeutic approaches for the disease.
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Affiliation(s)
- Sergio A Jimenez
- Jefferson Institute of Molecular Medicine and The Scleroderma Center, Thomas Jefferson University, Philadelphia, PA, USA
| | - Sonsoles Piera-Velazquez
- Jefferson Institute of Molecular Medicine and The Scleroderma Center, Thomas Jefferson University, Philadelphia, PA, USA
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Sun C, Zhu H, Wang Y, Han Y, Zhang D, Cao X, Alip M, Nie M, Xu X, Lv L, Feng X, Sun L, Wang D. Serum metabolite differences detected by HILIC UHPLC-Q-TOF MS in systemic sclerosis. Clin Rheumatol 2023; 42:125-134. [PMID: 36127550 DOI: 10.1007/s10067-022-06372-z] [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: 04/08/2022] [Revised: 09/01/2022] [Accepted: 09/03/2022] [Indexed: 01/11/2023]
Abstract
BACKGROUND Systemic sclerosis (SSc) is a chronic autoimmune disease characterized by extensive fibrosis and vascular damage. Vasculopathy, activation of the immune system, and diffuse fibrosis are all involved in the fatal pathogenesis of SSc. However, little metabolomic research has been conducted in SSc. METHODS This study included 30 SSc patients and 30 healthy individuals. The metabolite differences in serum samples were analyzed using ultra-high-pressure liquid chromatography and quadrupole-time-of-flight mass spectrometry. Meanwhile, serum metabolites were analyzed in patients with systemic involvement (lung or skin fibrosis). RESULTS A total of 2360 ion peaks were detected, all of which were attributable to 38 metabolites. These metabolites primarily consisted of fatty acids, amino acids, and glycerophospholipids, which were the major metabolic pathways altered in SSc patients. Glutamine metabolism was the main pathway altered in SSc patients with lung involvement, whereas amino acid metabolism and steroid hormone biosynthesis were the main pathways altered in SSc patients with skin involvement. CONCLUSION These findings suggested that metabolic profiles and pathways differed between SSc patients and healthy people, potentially providing new targets for SSc-directed therapeutics and diagnostics. Key Points • Metabolic profiles and pathways differed between SSc patients and healthy people. • The levels of trans-dehydroandrosterone are substantially lower in lcSSc than in dcSSc, potentially providing new targets for SSc patients with skin involvement. • L-glutamine could be used as a serum metabolic marker and a therapeutic target for SSc patients with lung involvement.
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Affiliation(s)
- Chen Sun
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, People's Republic of China
| | - Huimin Zhu
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, People's Republic of China
| | - Yun Wang
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, People's Republic of China
| | - Yichen Han
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, People's Republic of China
| | - Dongdong Zhang
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, People's Republic of China
| | - Xi Cao
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, People's Republic of China
| | - Mihribangvl Alip
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, People's Republic of China
| | - Min Nie
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, People's Republic of China
| | - Xue Xu
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, People's Republic of China
| | - Liangjing Lv
- Department of Rheumatology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Xuebing Feng
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, People's Republic of China.
| | - Lingyun Sun
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, People's Republic of China.
| | - Dandan Wang
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, People's Republic of China.
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He X, Shi Y, Zeng Z, Tang B, Xiao X, Yu J, Zou P, Liu J, Xiao Y, Luo Y, Xiao R. Intimate intertwining of the pathogenesis of hypoxia and systemic sclerosis: A transcriptome integration analysis. Front Immunol 2022; 13:929289. [PMID: 36389675 PMCID: PMC9660309 DOI: 10.3389/fimmu.2022.929289] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 09/13/2022] [Indexed: 03/30/2024] Open
Abstract
OBJECTIVES Systemic sclerosis (SSc) is an autoimmune disease caused by various pathogenic factors, including hypoxia. Hypoxia stimulates the production of the extracellular matrix to promote fibrosis. However, the integrated function and the underlying mechanism of hypoxia in SSc are unclear. METHODS In the present study, we used Agilent SurePrint G3 Human Gene Expression v3 for the transcriptional sequencing of fibroblasts with and without hypoxia to detect differentially expressed genes (DEGs) in hypoxia. We analyzed the results with the transcriptome data of SSc lesions (GSE95065) to select the co-DEGs. Then, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed on the basis of the co-DEGs using the R package ClusterProfiler, which showed that hypoxia and cross talk of hypoxia with other pathogenic factors are involved in the pathogenesis of SSc. Furthermore, we constructed a protein-protein interaction (PPI) network of co-DEGs and screened two significant functional expression modules. RESULTS We identified nine hub genes (ALDH1A1, EGF, NOX4, LYN, DNTT, PTGS2, TKT, ACAA2, and ALDH3A1). These genes affect the pentose phosphate pathway, oxidative stress, and lipolysis. CONCLUSION Our study provides insights into the mechanisms underlying the effects of hypoxia on SSc pathogenesis, which will help to better understand SSc pathogenesis and develop new therapeutic strategies for SSc.
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Affiliation(s)
- Xinglan He
- Hunan Key Laboratory of Medical Epigenetics, Department of Dermatology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Yaqian Shi
- Hunan Key Laboratory of Medical Epigenetics, Department of Dermatology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Zhuotong Zeng
- Hunan Key Laboratory of Medical Epigenetics, Department of Dermatology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Bingsi Tang
- Hunan Key Laboratory of Medical Epigenetics, Department of Dermatology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Xuan Xiao
- Hunan Key Laboratory of Medical Epigenetics, Department of Dermatology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Jiangfan Yu
- Hunan Key Laboratory of Medical Epigenetics, Department of Dermatology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Puyu Zou
- Hunan Key Laboratory of Medical Epigenetics, Department of Dermatology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Jiani Liu
- Hunan Key Laboratory of Medical Epigenetics, Department of Dermatology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Yangfan Xiao
- Department of Anesthesiology, Clinical Nursing Teaching and Research Section, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Yangyang Luo
- Department of Dermatology, Hunan Children's Hospital, Changsha, China
| | - Rong Xiao
- Hunan Key Laboratory of Medical Epigenetics, Department of Dermatology, The Second Xiangya Hospital, Central South University, Changsha, China
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