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Frontiers in Immunology 2024Osteoarthritis (OA) is the most common form of arthritis, characterized by osteophyte formation, cartilage degradation, and structural and cellular alterations of the... (Review)
Review
Osteoarthritis (OA) is the most common form of arthritis, characterized by osteophyte formation, cartilage degradation, and structural and cellular alterations of the synovial membrane. Activated fibroblast-like synoviocytes (FLS) of the synovial membrane have been identified as key drivers, secreting humoral mediators that maintain inflammatory processes, proteases that cause cartilage and bone destruction, and factors that drive fibrotic processes. In normal tissue repair, fibrotic processes are terminated after the damage has been repaired. In fibrosis, tissue remodeling and wound healing are exaggerated and prolonged. Various stressors, including aging, joint instability, and inflammation, lead to structural damage of the joint and micro lesions within the synovial tissue. One result is the reduced production of synovial fluid (lubricants), which reduces the lubricity of the cartilage areas, leading to cartilage damage. In the synovial tissue, a wound-healing cascade is initiated by activating macrophages, Th2 cells, and FLS. The latter can be divided into two major populations. The destructive thymocyte differentiation antigen (THY)1 phenotype is restricted to the synovial lining layer. In contrast, the THY1 phenotype of the sublining layer is classified as an invasive one with immune effector function driving synovitis. The exact mechanisms involved in the transition of fibroblasts into a myofibroblast-like phenotype that drives fibrosis remain unclear. The review provides an overview of the phenotypes and spatial distribution of FLS in the synovial membrane of OA, describes the mechanisms of fibroblast into myofibroblast activation, and the metabolic alterations of myofibroblast-like cells.
Topics: Humans; Osteoarthritis; Fibroblasts; Animals; Phenotype; Fibrosis; Synoviocytes; Synovial Membrane
PubMed: 38895122
DOI: 10.3389/fimmu.2024.1385006 -
International Journal of Molecular... May 2024Pancreatic ductal adenocarcinoma (PDAC) is the most aggressive cancer with striking fibrosis, and its mortality rate is ranked second across human cancers.... (Review)
Review
Pancreatic ductal adenocarcinoma (PDAC) is the most aggressive cancer with striking fibrosis, and its mortality rate is ranked second across human cancers. Cancer-associated fibroblasts (CAFs) play a critical role in PDAC progression, and we reviewed the molecular understanding of PDAC CAFs and novel therapeutic potential at present. CAFs-associated genes (CAFGs) were tentatively classified into three categories by stroma specificity representing stroma/epithelia expression ratios (SE ratios). The recent classification using single cell transcriptome technology clarified that CAFs were composed of myofibroblasts (myCAFs), inflammatory CAFs (iCAFs), and other minor ones (e.g., POSTN-CAFs and antigen presenting CAFs, apCAFs). is a myCAFs marker, and myCAFs depletion by diphtheria toxin induces the rapid accumulation of cytotoxic T lymphocytes (CTLs) and therefore augment PDL1 antibody treatments. This finding proposes that myCAFs may be a critical regulator of tumor immunity in terms of PDAC progression. myCAFs are located in CAFs adjacent to tumor cells, while iCAFs marked by and/or are distant from tumor cells, where hypoxic and acidic environments being located in iCAFs putatively due to poor blood supply is consistent with and expressions. iCAFs may be shared with SASP (secretion-associated phenotypes) in senescent CAFs. myCAFs are classically characterized by CAFGs induced by , while chemoresistant CAFs with SASP may dependent on expression and accompanied by STAT3 activation. Recently, it was found that the unique metabolism of CAFs can be targeted to prevent PDAC progression, where PDAC cells utilize glucose, whereas CAFs in turn utilize lactate, which may be epigenetically regulated, mediated by its target genes including . In summary, CAFs have unique molecular characteristics, which have been rigorously clarified as novel therapeutic targets of PDAC progression.
Topics: Humans; Carcinoma, Pancreatic Ductal; Pancreatic Neoplasms; Cancer-Associated Fibroblasts; Gene Expression Regulation, Neoplastic; Tumor Microenvironment; Animals
PubMed: 38892190
DOI: 10.3390/ijms25116003 -
Cells Jun 2024Polycystic kidney disease (PKD) is characterized by extensive cyst formation and progressive fibrosis. However, the molecular mechanisms whereby the...
Polycystic kidney disease (PKD) is characterized by extensive cyst formation and progressive fibrosis. However, the molecular mechanisms whereby the loss/loss-of-function of Polycystin 1 or 2 (PC1/2) provokes fibrosis are largely unknown. The small GTPase RhoA has been recently implicated in , and we identified the RhoA/cytoskeleton/myocardin-related transcription factor (MRTF) pathway as an emerging mediator of epithelium-induced fibrogenesis. Therefore, we hypothesized that MRTF is activated by PC1/2 loss and plays a critical role in the fibrogenic reprogramming of the epithelium. The loss of PC1 or PC2, induced by siRNA in vitro, activated RhoA and caused cytoskeletal remodeling and robust nuclear MRTF translocation and overexpression. These phenomena were also manifested in PKD1 (RC/RC) and PKD2 (WS25/-) mice, with MRTF translocation and overexpression occurring predominantly in dilated tubules and the cyst-lining epithelium, respectively. In epithelial cells, a large cohort of PC1/PC2 downregulation-induced genes was MRTF-dependent, including cytoskeletal, integrin-related, and matricellular/fibrogenic proteins. Epithelial MRTF was necessary for the paracrine priming of the fibroblast-myofibroblast transition. Thus, MRTF acts as a prime inducer of epithelial fibrogenesis in PKD. We propose that RhoA is a common upstream inducer of both histological hallmarks of PKD: cystogenesis and fibrosis.
Topics: Animals; Fibrosis; Mice; rhoA GTP-Binding Protein; Polycystic Kidney Diseases; TRPP Cation Channels; Epithelial Cells; Humans; Trans-Activators; Cytoskeleton; Mice, Inbred C57BL
PubMed: 38891116
DOI: 10.3390/cells13110984 -
Cells May 2024Pulmonary fibrosis is a chronic, progressive, irreversible lung disease characterized by fibrotic scarring in the lung parenchyma. This condition involves the excessive... (Review)
Review
Pulmonary fibrosis is a chronic, progressive, irreversible lung disease characterized by fibrotic scarring in the lung parenchyma. This condition involves the excessive accumulation of extracellular matrix (ECM) due to the aberrant activation of myofibroblasts in the alveolar environment. Transforming growth factor beta (TGF-β) signaling is a crucial driver of fibrogenesis because it promotes excessive ECM deposition, thereby leading to scar formation and lung damage. A primary target of TGF-β signaling in fibrosis is Collagen Triple Helix Repeat Containing 1 (CTHRC1), a secreted glycoprotein that plays a pivotal role in ECM deposition and wound repair. TGF-β transcriptionally regulates CTHRC1 in response to tissue injury and controls the wound healing response through functional activity. CTHRC1 may also play an essential role in re-establishing and maintaining tissue homeostasis after wound closure by modulating both the TGF-β and canonical Wnt signaling pathways. This dual function suggests that CTHRC1 regulates tissue remodeling and homeostasis. However, deregulated CTHRC1 expression in pathogenic fibroblasts has recently emerged as a hallmark of fibrosis in multiple organs and tissues. This review highlights recent studies suggesting that CTHRC1 can serve as a diagnostic and prognostic biomarker for fibrosis in idiopathic pulmonary fibrosis, systemic sclerosis, and post-COVID-19 lung fibrosis. Notably, CTHRC1 expression is responsive to antifibrotic drugs that target the TGF-β pathway, such as pirfenidone and bexotegrast, indicating its potential as a biomarker of treatment success. These findings suggest that CTHRC1 may present new opportunities for diagnosing and treating patients with lung fibrosis.
Topics: Humans; Fibroblasts; Extracellular Matrix Proteins; Pulmonary Fibrosis; Animals; Transforming Growth Factor beta; Extracellular Matrix; Idiopathic Pulmonary Fibrosis
PubMed: 38891078
DOI: 10.3390/cells13110946 -
Journal of Nanobiotechnology Jun 2024Diabetic kidney disease (DKD), a chronic kidney disease, is characterized by progressive fibrosis caused due to persistent hyperglycemia. The development of fibrosis in...
Diabetic kidney disease (DKD), a chronic kidney disease, is characterized by progressive fibrosis caused due to persistent hyperglycemia. The development of fibrosis in DKD determines the patient prognosis, but no particularly effective treatment. Here, small extracellular vesicles derived from mesenchymal stem cells (MSC-sEV) have been used to treat DKD fibrosis. Single-cell RNA sequencing was used to analyze 27,424 cells of the kidney, we have found that a novel fibrosis-associated TGF-βArg1 macrophage subpopulation, which expanded and polarized in DKD and was noted to be profibrogenic. Additionally, ActinCol4a5 mesangial cells in DKD differentiated into myofibroblasts. Multilineage ligand-receptor and cell-communication analysis showed that fibrosis-associated macrophages activated the TGF-β/Smad2/3/YAP signal axis, which promotes mesangial fibrosis-like change and accelerates renal fibrosis niche. Subsequently, the transcriptome sequencing and LC-MS/MS analysis indicated that MSC-sEV intervention could restore the levels of the kinase ubiquitin system in DKD and attenuate renal interstitial fibrosis via delivering CK1δ/β-TRCP to mediate YAP ubiquitination degradation in mesangial cells. Our findings demonstrate the unique cellular and molecular mechanisms of MSC-sEV in treating the DKD fibrosis niche at a single-cell level and provide a novel therapeutic strategy for renal fibrosis.
Topics: Extracellular Vesicles; Fibrosis; Mesenchymal Stem Cells; Animals; Mice; Single-Cell Analysis; Diabetic Nephropathies; Transcriptome; Male; Mice, Inbred C57BL; Humans; Macrophages; Signal Transduction; Transforming Growth Factor beta1; Mesangial Cells; Kidney
PubMed: 38890734
DOI: 10.1186/s12951-024-02613-2 -
Communications Biology Jun 2024Organ fibrosis causes collagen fiber overgrowth and impairs organ function. Cardiac fibrosis after myocardial infarction impairs cardiac function significantly,...
Organ fibrosis causes collagen fiber overgrowth and impairs organ function. Cardiac fibrosis after myocardial infarction impairs cardiac function significantly, pulmonary fibrosis reduces gas exchange efficiency, and liver fibrosis disturbs the natural function of the liver. Its development is associated with the differentiation of fibroblasts into myofibroblasts and increased collagen synthesis. Fibrosis has organ specificity, defined by the heterogeneity of fibroblasts. Although this heterogeneity is established during embryonic development, it has not been defined yet. Fibroblastic differentiation of induced pluripotent stem cells (iPSCs) recapitulates the process by which fibroblasts acquire diversity. Here, we differentiated iPSCs into cardiac, hepatic, and dermal fibroblasts and analyzed their properties using single-cell RNA sequencing. We observed characteristic subpopulations with different ratios in each organ-type fibroblast group, which contained both resting and distinct ACTA2 myofibroblasts. These findings provide crucial information on the ontogeny-based heterogeneity of fibroblasts, leading to the development of therapeutic strategies to control fibrosis.
Topics: Humans; Induced Pluripotent Stem Cells; Fibroblasts; Cell Differentiation; Myofibroblasts; Cells, Cultured; Single-Cell Analysis; Fibrosis
PubMed: 38890483
DOI: 10.1038/s42003-024-06419-8 -
Trends in Molecular Medicine Jun 2024Cellular senescence is a key hallmark of aging. It has now emerged as a key mediator in normal tissue turnover and is associated with a variety of age-related diseases,... (Review)
Review
Cellular senescence is a key hallmark of aging. It has now emerged as a key mediator in normal tissue turnover and is associated with a variety of age-related diseases, including organ-specific fibrosis and systemic sclerosis (SSc). This review discusses the recent evidence of the role of senescence in tissue fibrosis, with an emphasis on SSc, a systemic autoimmune rheumatic disease. We discuss the physiological role of these cells, their role in fibrosis, and that targeting these cells specifically could be a new therapeutic avenue in fibrotic disease. We argue that targeting senescent cells, with senolytics or senomorphs, is a viable therapeutic target in fibrotic diseases which remain largely intractable.
PubMed: 38890028
DOI: 10.1016/j.molmed.2024.05.012 -
Redox Biology Jun 2024Myofibroblasts are key cellular effectors of corneal wound healing from trauma, surgery, or infection. However, their persistent deposition of disorganized extracellular...
Myofibroblasts are key cellular effectors of corneal wound healing from trauma, surgery, or infection. However, their persistent deposition of disorganized extracellular matrix can also cause corneal fibrosis and visual impairment. Recent work showed that the PPARγ agonist Troglitazone can mitigate established corneal fibrosis, and parallel in vitro data suggested this occurred through inhibition of the mitochondrial pyruvate carrier (MPC) rather than PPARγ. In addition to oxidative phosphorylation (Ox-Phos), pyruvate and other mitochondrial metabolites provide carbon for the synthesis of biological macromolecules. However, it is currently unclear how these roles selectively impact fibrosis. Here, we performed bioenergetic, metabolomic, and epigenetic analyses of corneal fibroblasts treated with TGF-β1 to stimulate myofibroblast trans-differentiation, with further addition of Troglitazone or the MPC inhibitor UK5099, to identify MPC-dependencies that may facilitate remodeling and loss of the myofibroblast phenotype. Our results show that a shift in energy metabolism is associated with, but not sufficient to drive cellular remodeling. Metabolites whose abundances were sensitive to MPC inhibition suggest that sustained carbon influx into the Krebs' cycle is prioritized over proline synthesis to fuel collagen deposition. Furthermore, increased abundance of acetyl-CoA and increased histone H3 acetylation suggest that epigenetic mechanisms downstream of metabolic remodeling may reinforce cellular phenotypes. Overall, our results highlight a novel molecular target and metabolic vulnerability that affects myofibroblast persistence in the context of corneal wounding.
PubMed: 38889622
DOI: 10.1016/j.redox.2024.103235 -
European Journal of Nuclear Medicine... Jun 2024Hepatic fibrosis develops as a response to chronic liver injury, resulting in the formation of fibrous scars. This process is initiated and driven by collagen-producing...
PURPOSE
Hepatic fibrosis develops as a response to chronic liver injury, resulting in the formation of fibrous scars. This process is initiated and driven by collagen-producing activated myofibroblasts which reportedly express high levels of platelet derived growth factor receptor-β (PDGFRβ). We therefore regard PDGFRβ as an anchor for diagnosis and therapy. The Fibrobody® SP02SP26-ABD is a biparatopic VHH-construct targeting PDGFRβ. Here, we explore its potential as a theranostic vector for liver fibrosis.
METHODS
Specificity, cross-species binding, and cellular uptake of SP02SP26-ABD was assessed using human, mouse and rat PDGFRβ ectodomains and PDGFRβ-expressing cells. Cellular uptake by PDGFRβ-expressing cells was also evaluated by equipping the Fibrobody® with auristatinF and reading out in vitro cytotoxicity. The validity of PDGFRβ as a marker for active fibrosis was confirmed in human liver samples and 3 mouse models of liver fibrosis (DDC, CCl, CDA-HFD) through immunohistochemistry and RT-PCR. After radiolabeling of DFO*-SP02SP26-ABD with Zr, its in vivo targeting ability was assessed in healthy mice and mice with liver fibrosis by PET-CT imaging, ex vivo biodistribution and autoradiography.
RESULTS
SP02SP26-ABD shows similar nanomolar affinity for human, mouse and rat PDGFRβ. Cellular uptake and hence subnanomolar cytotoxic potency of auristatinF-conjugated SP02SP26-ABD was observed in PDGFRβ-expressing cell lines. Immunohistochemistry of mouse and human fibrotic livers confirmed co-localization of PDGFRβ with markers of active fibrosis. In all three liver fibrosis models, PET-CT imaging and biodistribution analysis of [Zr]Zr-SP02SP26-ABD revealed increased PDGFRβ-specific uptake in fibrotic livers. In the DDC model, liver uptake was 12.15 ± 0.45, 15.07 ± 0.90, 20.23 ± 1.34, and 20.93 ± 4.35%ID/g after 1,2,3 and 4 weeks of fibrogenesis, respectively, compared to 7.56 ± 0.85%ID/g in healthy mice. Autoradiography revealed preferential uptake in the fibrotic (PDGFRβ-expressing) periportal areas.
CONCLUSION
The anti-PDGFRβ Fibrobody® SP02SP26-ABD shows selective and high-degree targeting of activated myofibroblasts in liver fibrosis, and qualifies as a vector for diagnostic and therapeutic purposes.
PubMed: 38888612
DOI: 10.1007/s00259-024-06785-9 -
Biochemistry. Biokhimiia May 2024Extensive skin damage requires specialized therapy that stimulates regeneration processes without scarring. The possibility of using combination of a collagen gel...
Extensive skin damage requires specialized therapy that stimulates regeneration processes without scarring. The possibility of using combination of a collagen gel application as a wound dressing and fibroblast attractant with verteporfin as an antifibrotic agent was examined in vivo and in vitro. In vitro effects of verteporfin on viability and myofibroblast markers expression were evaluated using fibroblasts isolated from human scar tissue. In vivo the collagen gel and verteporfin (individually and in combination) were applied into the wound to investigate scarring during skin regeneration: deviations in skin layer thickness, collagen synthesis, and extracellular matrix fibers were characterized. The results indicate that verteporfin reduces fibrotic phenotype by suppressing expression of the contractile protein Sm22α without inducing cell death. However, administration of verteporfin in combination with the collagen gel disrupts its ability to direct wound healing in a scarless manner, which may be related to incompatibility of the mechanisms by which collagen and verteporfin control regeneration.
Topics: Verteporfin; Humans; Collagen; Fibroblasts; Animals; Wound Healing; Antifibrotic Agents; Cells, Cultured; Tissue Scaffolds; Cicatrix; Male; Fibrosis; Skin
PubMed: 38880654
DOI: 10.1134/S0006297924050146