An inflammatory myofibroblastic tumour (IMT) is a rare neoplasm of mesenchymal origin, defined by myofibroblastic spindle cells accompanied by inflammatory cells, lymphocytes and eosinophils. Its symptomatology depends on the involved site and tends to mimic a malignant tumour clinically and radiologically. The head and neck region accounts for 5% of all IMTs. Here, we report a case of a 35-year-old woman, with no medical history, who presented with a mouth-opening limitation of 8 mm evolving for three years and occurring six months after of a wisdom tooth extraction. She also experienced a recent occurrence of left eye ptosis and a converging strabismus. On examination, the patient had a body temperature at 37°C, with hypoesthaesia of the left chin and infraorbital area, without any other abnormality. Laboratory examinations did not reveal a biological inflammatory syndrome or rhabdomyolysis. The infectious investigations were all negative, as well as the immunological tests, in particular negative for anti-AChR and anti-MuSK antibodies. On the facial computed tomography (CT) scan, we noted an active reshuffle in the left mandible ascending branch with a thickening of the ipsilateral pterygoid muscles and the left temporal meningeal tissue. After corticosteroid therapy 0.7 mg/kg/j, we obtained an improvement in the patient\'s mouth-opening, thus a biopsy of the lesion was performed under local anaesthesia, revealing IMT. The patient continued the corticosteroids therapy with a progressive tapering resulting in a marked clinical improvement of the mouth-opening limitation and her ptosis.
CONCLUSIONS: An inflammatory myofibroblastic tumour (IMT) is a challenging disease.Given the variable clinical and radiological presentation of the disease, it is of paramount importance to know it, to be swiftly recognised so diagnosis can be promptly made.The adapted treatment should be immediately started to prevent possible life-threatening outcomes.

BACKGROUND: Irreversible pulmonary fibrosis induced by paraquat is the most prevalent cause of death in patients with paraquat poisoning. Pulmonary fibrosis is characterized by abnormal deposition of extracellular matrix (ECM). Currently, the role of fibrotic ECM microenvironment in paraquat-induced pulmonary fibrosis has not been established.
METHODS: Rat pulmonary fibrosis model was induced by paraquat, ATN-161 (an integrin-β1 antagonist) was given to investigate their effect on Rat survival and pulmonary fibrosis. Lungs were decellularized to generate normal and fibrotic acellular ECM scaffolds using Triton and SDS. Fibroblasts were cocultured with ECM scaffolds to established 3D culture systems to investigate the relationship between fibrotic ECM and the differentiation of fibroblasts. Then we explored the effect of fibrotic ECM microenvironment systematically promoting on integrin-β1/FAK/ERK1/2 pathway and established 3D culture systems to investigate the relationship between fibrotic ECM and the differentiation of fibroblasts.
RESULTS: Antagonism of integrin-β1 could alleviate paraquat-induced pulmonary fibrosis and ameliorate survival status of rats. Compared to normal ECM, fibrotic extracellular microenvironment promoted the differentiation of fibroblasts to myofibroblasts. Antagonism of integrin-β1 could also ameliorate the promotion of fibrotic extracellular microenvironment on differentiation of fibroblasts to myofibroblasts. Fibrotic ECM microenvironment promotes fibroblasts transforming into myofibroblasts through integrin-β1/FAK/ERK1/2 signaling pathway. Moreover, this phenomenon holds independent on exogenous integrin-β1.
CONCLUSIONS: Activation of integrin-β1/FAK/ERK1/2 pathway aggravates paraquat-induced pulmonary fibrosis depend on fibrotic ECM and integrin-β1 may be a prospective therapeutic target for paraquat-induced pulmonary fibrosis in the future.

Portal vein thrombosis (PVT) is a challenging and controversial complication of cirrhosis. Experimental models that reproduce cirrhotic PVT and effective pharmacological therapies are limited. We aimed to investigate the nature course and mechanisms of PVT in cirrhosis. A novel PVT model was developed via two-step total portal vein ligation in healthy and thioacetamide (TAA)-cirrhotic rats. Circulating and liver-infiltrating neutrophils were isolated from individuals with cirrhosis to examine neutrophil extracellular traps (NETs) and explore their unique characteristics and implications in PVT-associated fibrosis in cirrhosis. We further validated macrophage-myofibroblast transition (MMT) via multiplex immunofluorescence and single-cell sequencing. In the experimental model, cirrhosis promoted PVT development and portal vein intimal thickening. Interestingly, cirrhosis promoted spontaneous resolution of PVT due to instability of thrombus structure, along with pulmonary and intrahepatic clots. NETs-MMT mediate cirrhotic PVT and PVT-associated fibrosis, including fibrotic thrombus remodeling and increased hepatic collagen deposition. Mechanistically, caspase-4-dependent activation of neutrophils and GSDMD mediated the formation of NETs. The extracellular DNA of NETs promoted TGF-β1/Smad3-driven MMT. Inhibiting GSDMD with disulfiram suppressed cirrhotic PVT and prevented associated fibrosis. The cirrhotic PVT model reflected the following three main characteristics of cirrhotic PVT: spontaneous resolution, immunothrombosis, and intimal fibrosis. Targeting NETs with GSDMD inhibitors may serve as a new therapeutic concept to treat cirrhotic PVT.

The switching of the fibroblast phenotype to myofibroblast is a hallmark of a wide variety of tissue pathologies. This phenotypical switch is known to be influenced not only by humoral factors such as TGF-β, but also by mechanical and physical cues in the cellular environment, and is accompanied by distinctive changes in cell morphology. However, the causative link between these cues, the concomitant morphological changes, and the resulting phenotypic switch remain elusive. Here, we use protein micropatterning to spatially control dermal fibroblast adhesion without invoking exogenous mechanical changes and demonstrate that varying the spatial configuration of focal adhesions (FAs) is sufficient to direct fibroblast phenotype. We further developed an automated morphometry analysis pipeline, which revealed FA eccentricity as the primary determinant of cell-state positioning along the spectrum of fibroblast phenotype. Moreover, linear fibronectin patterns that constrain the FAs were found to promote a further phenotype transition, characterized by dispersed expression of alpha-smooth muscle actin, pointing to an interesting possibility of controlling fibroblast phenotype beyond the canonical fibroblast-myofibroblast axis. Together, our study reveals that the spatial configuration of adhesion to the cellular microenvironment is a key factor governing fibroblast morphotype and phenotype, shedding new light on fibroblast phenotype regulation.

The transition of fibroblasts to myofibroblasts (FMT) represents a pivotal process in wound healing, tissue repair, and fibrotic diseases. This intricate transformation involves dynamic changes in cellular morphology, gene expression, and extracellular matrix remodeling. While extensively studied at the molecular level, recent research has illuminated the regulatory roles of non-coding RNAs (ncRNAs) in orchestrating FMT. This review explores the emerging roles of ncRNAs, including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), in regulating this intricate process. NcRNAs interface with key signaling pathways, transcription factors, and epigenetic mechanisms to fine-tune gene expression during FMT. Their functions are critical in maintaining tissue homeostasis, and disruptions in these regulatory networks have been linked to pathological fibrosis across various tissues. Understanding the dynamic roles of ncRNAs in FMT bears therapeutic promise. Targeting specific ncRNAs holds potential to mitigate exaggerated myofibroblast activation and tissue fibrosis. However, challenges in delivery and specificity of ncRNA-based therapies remain. In summary, ncRNAs emerge as integral regulators in the symphony of FMT, orchestrating the balance between quiescent fibroblasts and activated myofibroblasts. As research advances, these ncRNAs appear to be prospects for innovative therapeutic strategies, offering hope in taming the complexities of fibrosis and restoring tissue equilibrium.

Fibrosis is characterized by excessive deposition of extracellular matrix proteins, particularly collagen, caused by myofibroblasts in response to chronic inflammation. Although G protein-coupled receptors (GPCRs) are among the targets of current antifibrotic drugs, no drug has yet been approved to stop fibrosis progression. Herein, we aimed to identify GPCRs with profibrotic effects. In gene expression analysis of mouse lungs with induced fibrosis, eight GPCRs were identified, showing a >2-fold increase in mRNA expression after fibrosis induction. Among them, we focused on Gpr176 owing to its significant correlation with a myofibroblast marker α-smooth muscle actin (αSMA), the profibrotic factor transforming growth factor β1 (TGFβ1), and collagen in a human lung gene expression database. Similar to the lung fibrosis model, increased Gpr176 expression was also observed in other organs affected by fibrosis, including the kidney, liver, and heart, suggesting its role in fibrosis across various organs. Furthermore, fibroblasts abundantly expressed Gpr176 compared to alveolar epithelial cells, endothelial cells, and macrophages in the fibrotic lung. GPR176 expression was unaffected by TGFβ1 stimulation in rat renal fibroblast NRK-49 cells, whereas knockdown of Gpr176 by siRNA reduced TGFβ1-induced expression of αSMA, fibronectin, and collagen as well as Smad2 phosphorylation. This suggested that Gpr176 regulates fibroblast activation. Consequently, Gpr176 acts in a profibrotic manner, and inhibiting its activity could potentially prevent myofibroblast differentiation and improve fibrosis. Developing a GPR176 inverse agonist or allosteric modulator is a promising therapeutic approach for fibrosis.

Idiopathic pulmonary fibrosis is a lethal, progressive, and irreversible condition that has become a significant focus of medical research due to its increasing incidence. This rising trend presents substantial challenges for patients, healthcare providers, and researchers. Despite the escalating burden of pulmonary fibrosis, the available therapeutic options remain limited. Currently, the United States Food and Drug Administration has approved two drugs for the treatment of pulmonary fibrosis-nintedanib and pirfenidone. However, their therapeutic effectiveness is limited, and they cannot reverse the fibrosis process. Additionally, these drugs are associated with significant side effects. Myofibroblasts play a central role in the pathophysiology of pulmonary fibrosis, significantly contributing to its progression. Consequently, strategies aimed at inhibiting myofibroblast differentiation or promoting their dedifferentiation hold promise as effective treatments. This review examines the regulation of myofibroblast dedifferentiation, exploring various signaling pathways, regulatory targets, and potential pharmaceutical interventions that could provide new directions for therapeutic development.

Nonalcoholic steatohepatitis (NASH) and alcoholic hepatitis (AH) affect a large part of the general population worldwide. Dysregulation of lipid metabolism and alcohol toxicity drive disease progression by the activation of hepatic stellate cells and the capillarization of liver sinusoidal endothelial cells. Collagen deposition, along with sinusoidal remodeling, alters sinusoid structure, resulting in hepatic inflammation, portal hypertension, liver failure, and other complications. Efforts were made to develop treatments for NASH and AH. However, the success of such treatments is limited and unpredictable. We report a strategy for NASH and AH treatment involving the induction of integrin αvβ3-mediated cell apoptosis using a rationally designed protein (ProAgio). Integrin αvβ3 is highly expressed in activated hepatic stellate cells (αHSCs), the angiogenic endothelium, and capillarized liver sinusoidal endothelial cells (caLSECs). ProAgio induces the apoptosis of these disease-driving cells, therefore decreasing collagen fibril, reversing sinusoid remodeling, and reducing immune cell infiltration. The reversal of sinusoid remodeling reduces the expression of leukocyte adhesion molecules on LSECs, thus decreasing leukocyte infiltration/activation in the diseased liver. Our studies present a novel and effective approach for NASH and AH treatment.

Contrary to the initial belief that myofibroblasts are terminally differentiated cells, myofibroblasts have now been widely recognized as an activation state that is reversible. Therefore, strategies targeting myofibroblast to be a quiescent state may be an effective way for antihypertrophic scar therapy. Graphene quantum dots (GQDs), a novel zero-dimensional and carbon-based nanomaterial, have recently garnered significant interest in nanobiomedicine, owing to their excellent biocompatibility, tunable photoluminescence, and superior physiological stability. Although multiple nanoparticles have been used to alleviate hypertrophic scars, a GQD-based therapy has not been reported. Our in vivo studies showed that GQDs exhibited significant antiscar efficacy, with scar appearance improvement, collagen reduction and rearrangement, and inhibition of myofibroblast overproliferation. Further in vitro experiments revealed that GQDs inhibited α-SMA expression, collagen synthesis, and cell proliferation and migration, inducing myofibroblasts to become quiescent fibroblasts. Mechanistic studies have demonstrated that the effect of GQDs on myofibroblast proliferation blocked cell cycle progression by disrupting the cyclin-CDK-E2F axis. This study suggests that GQDs, which promote myofibroblast-to-fibroblast transition, could be a novel antiscar nanomedicine for the treatment of hypertrophic scars and other types of pathological fibrosis.

UNASSIGNED: Bladder cancer (BC), as a common type of cancer, has a poor prognosis, also some common invasive prognostic or therapeutic markers are difficult to obtain, which makes further treatment of BC difficult. Glycyl-tRNA synthetase (GARS), as one of the aminoacyl-tRNA synthetases that charge tRNAs with their cognate amino acids, has been identified as a target in many diseases, including tumors.
UNASSIGNED: Bioassay analysis revealed that GARS was in high expression in most cancer tissues. The expression of GARS gene in BC tissues could assess the prognosis of BC patients, and the expression in urinary extracellular vesicles (uEVs) of patients was positively correlated with the expression in tissues. In addition to this, we analyzed GARS-related differential gene expression, copy number variation (CNV) and mutation profiles, potential biological functions, immune cell infiltration and drug sensitivity. In vivo and vitro tumorigenic experiments were performed to validate the function of GARS. Single-cell data were used to further analyze its role in the microenvironment.
UNASSIGNED: In our study, we found that GARS was highly expressed in 30 cancer tissues including BC, and high GARS expression was negatively correlated with the prognosis of BC patients. To address this phenomenon, we analyzed the differential genes between high and low GARS groups by enrichment analysis, and identified the biological signaling pathways that were mainly enriched for their functions, and found that the enrichment was found in immune-related signaling pathways and regulation of cell-cell adhesion. Then we found that GARS was positively associated with immune cell infiltration in BC, and some common immune checkpoints were significantly overexpressed in the GARS-high group. Besides, we found that GARS was enriched in myofibroblasts in the tumor microenvironment, and the enrichment was positively correlated with epithelial-mesenchymal transition (EMT)-related genes. This study also showed a positive correlation between GARS and BC RNA stemness. Patients in the GARS-high group had considerably higher rates of P53 and Titin (TTN) mutations than those in the GARS-low group. Drug Sensitivity analysis screened for drugs that were more sensitive to GARS-high patients. Further, we found that knockdown of GARS significantly inhibited the proliferation, migration and invasion ability both in vivo and in vitro. Finally, we found that in patients with high GARS the expression in uEVs was also at a high level.
UNASSIGNED: In summary, this study provided evidence that GARS can be used as a prognostic and therapeutic marker for BC, we can detect GARS in uEVs instead of tissue, to provide a new, simple, noninvasive way to obtain prognostic and therapeutic markers for BC patients.