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Asian Journal of Surgery Jun 2024
PubMed: 38876870
DOI: 10.1016/j.asjsur.2024.05.266 -
Fibrosis (Hong Kong, China) Dec 2023The composition of extracellular matrix (ECM) is altered during pathologic scarring in damaged organs including the lung. One major change in the ECM involves the...
The composition of extracellular matrix (ECM) is altered during pathologic scarring in damaged organs including the lung. One major change in the ECM involves the cross-linking of collagen, which promotes fibroblast to myofibroblast differentiation. We examined the role of lysyl oxidase (LOX)-like 2 in lung progenitors and fibroblasts cultured from normal or IPF lung samples and in a humanized mouse model of IPF using a monoclonal antibody (Simtuzumab). Primary lung fibroblasts from normal donor lungs and IPF lung explants were examined for expression of LOXL2. Targeting LOXL2 with Simtuzumab on normal and IPF fibroblasts was examined both and for synthetic, functional, and profibrotic properties. LOXL2 was increased at transcript and protein level in IPF compared with normal lung samples. In a dose-dependent manner, Simtuzumab enhanced differentiation of fibroblasts into myofibroblasts. Inhibition of LOXL2 also enhanced fibroblast invasion and accelerated the outgrowth of fibroblasts from dissociated human lung cell preparations. Finally, preventative or delayed delivery of Simtuzumab enhanced lung fibrosis in a humanized mouse model of pulmonary fibrosis. Consistent with its failure in a Phase 2 clinical trial, Simtuzumab exhibited no therapeutic efficacy in translational and assays.
PubMed: 38873180
DOI: 10.35534/fibrosis.2023.10007 -
Physiological Reports Jun 2024ERK3/MAPK6 activates MAP kinase-activated protein kinase (MK)-5 in selected cell types. Male MK5 haplodeficient mice show reduced hypertrophy and attenuated increase in...
ERK3/MAPK6 activates MAP kinase-activated protein kinase (MK)-5 in selected cell types. Male MK5 haplodeficient mice show reduced hypertrophy and attenuated increase in Col1a1 mRNA in response to increased cardiac afterload. In addition, MK5 deficiency impairs cardiac fibroblast function. This study determined the effect of reduced ERK3 on cardiac hypertrophy following transverse aortic constriction (TAC) and fibroblast biology in male mice. Three weeks post-surgery, ERK3, but not ERK4 or p38α, co-immunoprecipitated with MK5 from both sham and TAC heart lysates. The increase in left ventricular mass and myocyte diameter was lower in TAC-ERK3 than TAC-ERK3 hearts, whereas ERK3 haploinsufficiency did not alter systolic or diastolic function. Furthermore, the TAC-induced increase in Col1a1 mRNA abundance was diminished in ERK3 hearts. ERK3 immunoreactivity was detected in atrial and ventricular fibroblasts but not myocytes. In both quiescent fibroblasts and "activated" myofibroblasts isolated from adult mouse heart, siRNA-mediated knockdown of ERK3 reduced the TGF-β-induced increase in Col1a1 mRNA. In addition, intracellular type 1 collagen immunoreactivity was reduced following ERK3 depletion in quiescent fibroblasts but not myofibroblasts. Finally, knocking down ERK3 impaired motility in both atrial and ventricular myofibroblasts. These results suggest that ERK3 plays an important role in multiple aspects of cardiac fibroblast biology.
Topics: Animals; Male; Mice; Fibroblasts; Collagen Type I; Collagen Type I, alpha 1 Chain; Myocardium; Mitogen-Activated Protein Kinase 6; Mice, Inbred C57BL; Protein Serine-Threonine Kinases; Intracellular Signaling Peptides and Proteins; Mitogen-Activated Protein Kinase 3; Cells, Cultured; Cardiomegaly; Myocytes, Cardiac
PubMed: 38872461
DOI: 10.14814/phy2.16108 -
Cellular & Molecular Immunology Jun 2024Managing renal fibrosis is challenging owing to the complex cell signaling redundancy in diseased kidneys. Renal fibrosis involves an immune response dominated by...
Managing renal fibrosis is challenging owing to the complex cell signaling redundancy in diseased kidneys. Renal fibrosis involves an immune response dominated by macrophages, which activates myofibroblasts in fibrotic niches. However, macrophages exhibit high heterogeneity, hindering their potential as therapeutic cell targets. Herein, we aimed to eliminate specific macrophage subsets that drive the profibrotic immune response in the kidney both temporally and spatially. We identified the major profibrotic macrophage subset (Fn1Spp1Arg1) in the kidney and then constructed a 12-mer glycopeptide that was designated as bioactivated in vivo assembly PK (BIVA-PK) to deplete these cells. BIVA-PK specifically binds to and is internalized by profibrotic macrophages. By inducing macrophage cell death, BIVA-PK reshaped the renal microenvironment and suppressed profibrotic immune responses. The robust efficacy of BIVA-PK in ameliorating renal fibrosis and preserving kidney function highlights the value of targeting macrophage subsets as a potential therapy for patients with CKD.
PubMed: 38871810
DOI: 10.1038/s41423-024-01190-6 -
Oral Surgery, Oral Medicine, Oral... May 2024
PubMed: 38871621
DOI: 10.1016/j.oooo.2024.04.105 -
Annales D'endocrinologie Jun 2024This lecture delves into the pivotal role of adipose tissue in obesity and its response to weight loss, particularly via bariatric surgery. Adipose tissue, responsible... (Review)
Review
This lecture delves into the pivotal role of adipose tissue in obesity and its response to weight loss, particularly via bariatric surgery. Adipose tissue, responsible for storing excess energy, undergoes significant changes during obesity, marked by inflammation and fibrosis. Bariatric surgery, serving as a model, allow the exploration of adipose tissue remodeling post-weight loss, inducing metabolic and fibro-inflammatory shifts. Despite successful weight loss, inflammation and fibrosis persist, as evidenced by changes in immune cells, altered cytokine profiles and the accumulation of extracellular matrix (ECM). Unfortunately, these lingering effects impair the normal adipose tissue function. In this context, adipose progenitors, an heterogenous resident population of mesenchymal stromal cells, display functions important to fibrosis development, capable of differentiating into myofibroblasts and contributing to ECM deposition. Particularly, a distinct subpopulation of adipose progenitors with high CD9 expression (CD9high) is associated with fibrosis and insulin resistance in human obesity. The persistence of fibrosis post-weight loss poses challenges, correlating with metabolic dysfunction despite improved glucose tolerance. A comprehensive understanding of the mechanisms driving adipose tissue remodeling and fibrosis post-weight loss is imperative for the development of effective treatments for obesity. The intricate interplay between adipose tissue, inflammation, and fibrosis underscores the necessity for further in-depth research to elucidate these mechanisms and formulate targeted therapies for obesity-related complications.
Topics: Humans; Bariatric Surgery; Adipose Tissue; Obesity; Fibrosis; Weight Loss; Inflammation; Insulin Resistance
PubMed: 38871506
DOI: 10.1016/j.ando.2024.05.008 -
Population modeling analyses of crizotinib in pediatric patients with ALK-positive advanced cancers.Pediatric Blood & Cancer Jun 2024Alterations in the ALK (anaplastic lymphoma kinase) gene play a critical role in pathogenesis of anaplastic large cell lymphoma (ALCL). Crizotinib is a small molecule...
BACKGROUND
Alterations in the ALK (anaplastic lymphoma kinase) gene play a critical role in pathogenesis of anaplastic large cell lymphoma (ALCL). Crizotinib is a small molecule competitive inhibitor of ALK, ROS1, and MET kinases and was approved for pediatric patients with ALK-positive relapsed or refractory, systemic ALCL, and ALK-positive unresectable, recurrent, or refractory inflammatory myofibroblastic tumors (IMT).
PROCEDURE
Crizotinib data from pediatric patients with relapsed or refractory solid tumors, IMT, or ALCL were included in the analyses. All patients received crizotinib orally at doses ranging from 100 to 365 mg/m twice daily (BID). PopPK analyses were conducted to characterize crizotinib disposition in pediatric patients. Exposure-response (ER) safety and antitumor analyses were conducted to characterize relationships between crizotinib dose or exposure with safety and antitumor activity endpoints of interest.
RESULTS
The population pharmacokinetic (popPK), ER safety, and ER antitumor analysis included 98, 110, and 36 pediatric patients, respectively. A one-compartment pharmacokinetic model with allometric scaling, first-order elimination, and first-order absorption with lag time adequately described the data. Natural log-transformed model-predicted crizotinib AUC (steady-state area under the concentration-time curve) demonstrated a significant, positive relationship with Grade ≥3 NEUTROPENIA and Any Grade VISION DISORDER. Crizotinib dose demonstrated a positive relationship with objective response rate.
CONCLUSIONS
No significant differences in PK were identified across a wide range of ages or across tumor types, suggesting body surface area (BSA)-based dosing adequately adjusted for differences in patient size to achieve similar systemic crizotinib exposures across young children and adolescent pediatric patients. None of the myelosuppressive events except Grade ≥3 NEUTROPENIA had significant relationships identified with crizotinib dose or exposure, suggesting crizotinib is a tolerable treatment with less hematological toxicity than traditional chemotherapy regimens for pediatric patients with ALK-mutated cancers. Results from the presented analyses support the pediatric dosing recommendations in the product label.
PubMed: 38867367
DOI: 10.1002/pbc.31139 -
Stem Cell Research & Therapy Jun 2024Hypertrophic scarring results from myofibroblast differentiation and persistence during wound healing. Currently no effective treatment for hypertrophic scarring exists...
BACKGROUND
Hypertrophic scarring results from myofibroblast differentiation and persistence during wound healing. Currently no effective treatment for hypertrophic scarring exists however, autologous fat grafting has been shown to improve scar elasticity, appearance, and function. The aim of this study was to understand how paracrine factors from adipose tissues and adipose-derived stromal cells (ADSC) affect fibroblast to myofibroblast differentiation.
METHODS
The transforming growth factor-β1 (TGF-β1) induced model of myofibroblast differentiation was used to test the effect of conditioned media from adipose tissue, ADSC or lipid on the proportion of fibroblasts and myofibroblasts.
RESULTS
Adipose tissue conditioned media inhibited the differentiation of fibroblasts to myofibroblasts but this inhibition was not observed following treatment with ADSC or lipid conditioned media. Hepatocyte growth factor (HGF) was readily detected in the conditioned medium from adipose tissue but not ADSC. Cells treated with HGF, or fortinib to block HGF, demonstrated that HGF was not responsible for the inhibition of myofibroblast differentiation. Conditioned media from adipose tissue was shown to reduce the proportion of myofibroblasts when added to fibroblasts previously treated with TGF-β1, however, conditioned media treatment was unable to significantly reduce the proportion of myofibroblasts in cell populations isolated from scar tissue.
CONCLUSIONS
Cultured ADSC or adipocytes have been the focus of most studies, however, this work highlights the importance of considering whole adipose tissue to further our understanding of fat grafting. This study supports the use of autologous fat grafts for scar treatment and highlights the need for further investigation to determine the mechanism.
Topics: Myofibroblasts; Transforming Growth Factor beta1; Adipose Tissue; Cell Differentiation; Culture Media, Conditioned; Humans; Hepatocyte Growth Factor; Paracrine Communication; Phenotype; Cells, Cultured; Fibroblasts; Adipocytes; Stromal Cells
PubMed: 38867276
DOI: 10.1186/s13287-024-03776-3 -
Journal of Translational Medicine Jun 2024Fibrogenesis within ovarian endometrioma (endometrioma), mainly induced by transforming growth factor-β (TGF-β), is characterized by myofibroblast over-activation and...
BACKGROUND
Fibrogenesis within ovarian endometrioma (endometrioma), mainly induced by transforming growth factor-β (TGF-β), is characterized by myofibroblast over-activation and excessive extracellular matrix (ECM) deposition, contributing to endometrioma-associated symptoms such as infertility by impairing ovarian reserve and oocyte quality. However, the precise molecular mechanisms that underpin the endometrioma- associated fibrosis progression induced by TGF-β remain poorly understood.
METHODS
The expression level of lysine acetyltransferase 14 (KAT14) was validated in endometrium biopsies from patients with endometrioma and healthy controls, and the transcription level of KAT14 was further confirmed by analyzing a published single-cell transcriptome (scRNA-seq) dataset of endometriosis. We used overexpression, knockout, and knockdown approaches in immortalized human endometrial stromal cells (HESCs) or human primary ectopic endometrial stromal cells (EcESCs) to determine the role of KAT14 in TGF-β-induced fibrosis. Furthermore, an adeno-associated virus (AAV) carrying KAT14-shRNA was used in an endometriosis mice model to assess the role of KAT14 in vivo.
RESULTS
KAT14 was upregulated in ectopic lesions from endometrioma patients and predominantly expressed in activated fibroblasts. In vitro studies showed that KAT14 overexpression significantly promoted a TGF-β-induced profibrotic response in endometrial stromal cells, while KAT14 silencing showed adverse effects that could be rescued by KAT14 re-enhancement. In vivo, Kat14 knockdown ameliorated fibrosis in the ectopic lesions of the endometriosis mouse model. Mechanistically, we showed that KAT14 directly interacted with serum response factor (SRF) to promote the expression of α-smooth muscle actin (α-SMA) by increasing histone H4 acetylation at promoter regions; this is necessary for TGF-β-induced ECM production and myofibroblast differentiation. In addition, the knockdown or pharmacological inhibition of SRF significantly attenuated KAT14-mediating profibrotic effects under TGF-β treatment. Notably, the KAT14/SRF complex was abundant in endometrioma samples and positively correlated with α-SMA expression, further supporting the key role of KAT14/SRF complex in the progression of endometrioma-associated fibrogenesis.
CONCLUSION
Our results shed light on KAT14 as a key effector of TGF-β-induced ECM production and myofibroblast differentiation in EcESCs by promoting histone H4 acetylation via co-operating with SRF, representing a potential therapeutic target for endometrioma-associated fibrosis.
Topics: Adult; Animals; Female; Humans; Mice; Endometriosis; Endometrium; Fibrosis; Histone Acetyltransferases; Myofibroblasts; Serum Response Factor; Stromal Cells; Transforming Growth Factor beta; Up-Regulation; Adaptor Proteins, Signal Transducing
PubMed: 38867256
DOI: 10.1186/s12967-024-05243-2 -
Biomedicine & Pharmacotherapy =... Jul 2024Peritoneal fibrosis, a common complication observed in long-term peritoneal dialysis patients, can gradually lead to ultrafiltration failure and the development of...
Peritoneal fibrosis, a common complication observed in long-term peritoneal dialysis patients, can gradually lead to ultrafiltration failure and the development of encapsulating peritoneal sclerosis. Although mechanisms of peritoneal fibrosis have been proposed, effective therapeutic options are unsatisfactory. Recently, several tyrosine kinase inhibitors have proven to be anti-fibrosis in rodent models. To assess the potential therapeutic effects of tyrosine kinase inhibitors on peritoneal fibrosis in the larger animal model, a novel porcine model of peritoneal fibrosis induced by 40 mM methylglyoxal in 2.5 % dialysate was established, and two different doses (20 mg/kg and 30 mg/kg) of sorafenib were given orally to evaluate their therapeutic efficacy in this study. Our results showed that sorafenib effectively reduced adhesions between peritoneal organs and significantly diminished the thickening of both the parietal and visceral peritoneum. Angiogenesis, vascular endothelial growth factor A production, myofibroblast infiltration, and decreased endothelial glycocalyx resulting from dialysate and methylglyoxal stimulations were also alleviated with sorafenib. However, therapeutic efficacy in ameliorating loss of mesothelial cells, restoring decreased ultrafiltration volume, and improving elevated small solutes transport rates was limited. In conclusion, this study demonstrated that sorafenib could potentially be used for peritoneal fibrosis treatment, but applying sorafenib alone might not be sufficient to fully rescue methylglyoxal-induced peritoneal defects.
Topics: Animals; Sorafenib; Pyruvaldehyde; Peritoneal Fibrosis; Protein Kinase Inhibitors; Swine; Female; Disease Models, Animal; Phenylurea Compounds; Vascular Endothelial Growth Factor A; Peritoneum; Tyrosine Kinase Inhibitors
PubMed: 38865848
DOI: 10.1016/j.biopha.2024.116905