1
|
Kostallari E, Wei B, Sicard D, Li J, Cooper SA, Gao J, Dehankar M, Li Y, Cao S, Yin M, Tschumperlin DJ, Shah VH. Stiffness is associated with hepatic stellate cell heterogeneity during liver fibrosis. Am J Physiol Gastrointest Liver Physiol 2022; 322:G234-G246. [PMID: 34941452 PMCID: PMC8793867 DOI: 10.1152/ajpgi.00254.2021] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The fibrogenic wound-healing response in liver increases stiffness. Stiffness mechanotransduction, in turn, amplifies fibrogenesis. Here, we aimed to understand the distribution of stiffness in fibrotic liver, how it impacts hepatic stellate cell (HSC) heterogeneity, and identify mechanisms by which stiffness amplifies fibrogenic responses. Magnetic resonance elastography and atomic force microscopy demonstrated a heterogeneous distribution of liver stiffness at macroscopic and microscopic levels, respectively, in a carbon tetrachloride (CCl4) mouse model of liver fibrosis as compared with controls. High stiffness was mainly attributed to extracellular matrix dense areas. To identify a stiffness-sensitive HSC subpopulation, we performed single-cell RNA sequencing (scRNA-seq) on primary HSCs derived from healthy versus CCl4-treated mice. A subcluster of HSCs was matrix-associated with the most upregulated pathway in this subpopulation being focal adhesion signaling, including a specific protein termed four and a half LIM domains protein 2 (FHL2). In vitro, FHL2 expression was increased in primary human HSCs cultured on stiff matrix as compared with HSCs on soft matrix. Moreover, FHL2 knockdown inhibited fibronectin and collagen 1 expression, whereas its overexpression promoted matrix production. In summary, we demonstrate stiffness heterogeneity at the whole organ, lobular, and cellular level, which drives an amplification loop of fibrogenesis through specific focal adhesion molecular pathways.NEW & NOTEWORTHY The fibrogenic wound-healing response in liver increases stiffness. Here, macro and microheterogeneity of liver stiffness correlate with HSC heterogeneity in a hepatic fibrosis mouse model. Fibrogenic HSCs localized in stiff collagen-high areas upregulate the expression of focal adhesion molecule FHL2, which, in turn, promotes extracellular matrix protein expression. These results demonstrate that stiffness heterogeneity at the whole organ, lobular, and cellular level drives an amplification loop of fibrogenesis through specific focal adhesion molecular pathways.
Collapse
Affiliation(s)
- Enis Kostallari
- 1Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota
| | - Bo Wei
- 1Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota,2Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu, China
| | - Delphine Sicard
- 3Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
| | - Jiahui Li
- 4Department of Radiology, Mayo Clinic, Rochester, Minnesota
| | - Shawna A. Cooper
- 5Department of Biochemistry and Molecular Biology, Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, Minnesota
| | - Jinhang Gao
- 1Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota,2Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu, China
| | - Mrunal Dehankar
- 6Division of Computational Biology, Department of Quantitative Health Sciences, Mayo Clinic, Rochester, Minnesota
| | - Ying Li
- 6Division of Computational Biology, Department of Quantitative Health Sciences, Mayo Clinic, Rochester, Minnesota
| | - Sheng Cao
- 1Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota
| | - Meng Yin
- 4Department of Radiology, Mayo Clinic, Rochester, Minnesota
| | | | - Vijay H. Shah
- 1Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota
| |
Collapse
|