TGF-β as a driver of fibrosis: physiological roles and therapeutic opportunities

The role and molecular mechanism of CTHRC1 in fibrosis

Fibrosis, a pathological state characterized by the excessive accumulation of extracellular matrix components, is primarily driven by the overactivation of fibroblasts. This condition becomes particularly pronounced under chronic inflammatory conditions. Fibrosis can occur in several tissues throughout the body. Among the notable discoveries in the study of fibrosis is the role of Collagen Triple Helix Repeat Containing-1 (CTHRC1), a protein that has emerged as a critical regulator in the fibrotic process. CTHRC1 is rapidly expressed on the outer membrane of fibroblasts and intimal smooth muscle cells following vascular injury, such as that induced by balloon angioplasty. This expression denotes the organism efforts to repair and restructure compromised tissue, signifying a critical component of the tissue repair mechanism in reaction to fibrosis. It plays a pivotal role in promoting cell migration and aiding tissue repair post-injury, contributing significantly to various pathophysiological processes including revascularization, bone formation, developmental morphological changes, inflammatory arthritis, and the progression of cancer. Significantly, researchers have observed marked expression of CTHRC1 across a variety of fibrotic conditions, closely associating it with the progression of the disease. Intervention with CTHRC1 can affect the occurrence and progression of fibrosis. This review aims to comprehensively explore the role and underlying mechanisms of CTHRC1 in fibrotic diseases, highlighting its potential as a key target for therapeutic interventions.

Serum deprivation protein response intervenes in the proliferation, motility, and extracellular matrix production in keloid fibroblasts by blocking the amplification of TGF-β1/SMAD signal cascade via ERK1/2

Keloid formation has been linked to abnormal fibroblast function, such as excessive proliferation and extracellular matrix (ECM) production. Serum deprivation protein response (SDPR) is a crucial regulator of cellular function under diverse pathological conditions, yet its role in keloid formation remains unknown. The current work investigated the function of SDPR in regulating the proliferation, motility, and ECM production of keloid fibroblasts (KFs), as well as to decipher the mechanisms involved. Analysis of RNA sequencing data from the GEO database demonstrated significant down-regulation of SDPR in KF compared to normal fibroblasts (NFs). This down-regulation was also observed in clinical keloid specimens and isolated KFs. Overexpression of SDPR suppressed the proliferation, motility, and ECM production of KFs, while depletion of SDPR exacerbated the enhancing impact of TGF-β1 on the proliferation, motility, and ECM production of NFs. Mechanistic studies revealed that SDPR overexpression repressed TGF-β/Smad signal cascade activation in KFs along with decreased levels of phosphorylated Samd2/3, while SDPR depletion exacerbated TGF-β/Smad activation in TGF-β1-stimulated NFs. SDPR overexpression also repressed ERK1/2 activation in KFs, while SDPR depletion exacerbated ERK1/2 activation in TGF-β1-stimulated NFs. Inhibition of ERK1/2 abolished SDPR-depletion-induced TGF-β1/Smad activation, cell proliferation, motility, and ECM production in NFs. In conclusion, SDPR represses the proliferation, motility, and ECM production in KFs by blocking the TGF-β1/Smad pathway in an ERK1/2-dependent manner. The findings highlight the role of SDPR in regulating abnormal behaviors of fibroblasts associated with keloid formation and suggest it as a potential target for anti-keloid therapy development.

Chemically Defined Organoid Culture System for Cholangiocyte Differentiation

Cholangiocyte organoids provide a powerful platform for applications ranging from in vitro modeling to tissue engineering for regenerative medicine. However, their expansion and differentiation are typically conducted in animal-derived hydrogels, which impede the full maturation of organoids into functional cholangiocytes. In addition, these hydrogels are poorly defined and complex, limiting the clinical applicability of organoids. In this study, a novel medium composition combined with synthetic polyisocyanopeptide (PIC) hydrogels to enhance the maturation of intrahepatic cholangiocyte organoids (ICOs) into functional cholangiocytes is utilized. ICOs cultured in the presence of sodium butyrate and valproic acid, a histone deacetylase inhibitor, and a Notch signaling activator, respectively, in PIC hydrogel exhibit a more mature phenotype, as evidenced by increased expression of key cholangiocyte markers, crucial for biliary function. Notably, mature cholangiocyte organoids in PIC hydrogel display apical-out polarity, in contrast to the traditional basal-out polarization of ICOs cultured in Matrigel. Moreover, these mature cholangiocyte organoids effectively model the biliary pro-fibrotic response induced by transforming growth factor beta. Taken together, an animal-free, chemically defined culture system that promotes the ICOs into mature cholangiocytes with apical-out polarity, facilitating regenerative medicine applications and in vitro studies that require access to the apical membrane, is developed.

Transcriptomic analysis of Paraoxonase 1 expression in hepatocellular carcinoma and its potential impact on tumor immunity

BACKGROUND

Hepatocellular carcinoma (HCC) is characterized by a complex pathogenesis that confers aggressive malignancy, leading to a lack of dependable biomarkers for predicting invasion and metastasis, which results in poor prognoses in patients with HCC. Glycogen storage disease (GSD) is an uncommon metabolic disorder marked by hepatomegaly and liver fibrosis. Notably, hepatic adenomas in GSD patients present a heightened risk of malignancy compared to those in individuals without the disorder. In this investigation, PON1 emerged as a potential pivotal gene for HCC through bioinformatics analysis.

METHODS

Transcriptomic profiling data of liver cancer were collected and integrated from TCGA and GEO databases. Bioinformatics analysis was conducted to identify mutated mRNAs associated with GSD, and the PON1 gene was selected as a key gene. Patients were grouped based on the expression levels of PON1, and differences in clinical characteristics, biological pathways, immune infiltration, and expression of immune checkpoints were compared.

RESULTS

The expression levels of the PON1 gene showed significant differences between the high-expression group and the low-expression group in HCC patients. Further analysis indicated that the PON1 gene at different expression levels might influence the clinical manifestations, biological processes, immune infiltration, and expression of immune checkpoints in HCC. Additionally, immunohistochemistry (IHC) results revealed high expression of PON1 in normal tissues and low expression in HCC tissues. These findings provide important clues and future research directions for the early diagnosis, prognosis, immunotherapy, and potential molecular interactions of HCC.

CONCLUSION

Our investigation underscores the noteworthy prognostic significance of PON1 in HCC, suggesting its potential pivotal role in modulating tumor progression and immune cell infiltration. These findings establish PON1 as a novel tumor biomarker with significant implications for the prognosis, targeted therapy, and immunotherapy of patients with HCC.

TGF-β1 maintains the developmental potential of embryonic submandibular gland epithelia separated with mesenchyme

Objective

The objective of this study was to investigate the impact of transforming growth factor β1 (TGF-β1) on epithelial development using an ex vivo model of submandibular gland (SMG) epithelial-mesenchymal separation.

Materials and methods

The ex vivo model was established by separating E13 mouse SMG epithelia and mesenchyme, culturing them independently for 24 h, recombining them, and observing branching morphogenesis. Microarray analysis was performed to evaluate the transcriptome of epithelia treated with and without 1 ng/ml TGF-β1. Differential gene expression, pathway enrichment, and protein-protein interaction networks were analyzed. Quantitative real-time polymerase chain reaction, Western blot, and immunofluorescence were employed to validate the mRNA and protein levels.

Results

Recombined SMGs using separated epithelia and mesenchyme that were cultured for 24 h showed a significant inhibition of epithelial development compared to SMGs recombined immediately after separation. The level of TGF-β1 decreased in the SMG epithelia after epithelia-mesenchyme separation. Epithelia that were separated from mesenchyme for 24 h and pretreated with 1 ng/ml TGF-β1 continued to develop after recombination with mesenchyme, while epithelia without 1 ng/ml TGF-β1 treatment did not. Microarray analysis suggested pathway enrichment related to epithelial development and an upregulation of Sox2 in the 1 ng/ml TGF-β1-treated epithelia. Further experiments validated the phosphorylation of SMAD2 and SMAD3, upregulation of SOX2 and genes associated with epithelial development, including Prol1, Dcpp1, Bhlha15, Smgc, and Bpifa2. Additionally, 1 ng/ml TGF-β1 inhibited epithelial apoptosis by improving the BCL2/BAX ratio and reducing cleaved caspase 3.

Conclusions

The addition of 1 ng/ml TGF-β1 maintained the developmental potential of embryonic SMG epithelia separated from mesenchyme for 24 h. This suggests that 1 ng/ml TGF-β1 may partially compensate for the role of mesenchyme during the separation phase, although its compensation is limited in extent.

An antibody that inhibits TGF-β1 release from latent extracellular matrix complexes attenuates the progression of renal fibrosis

Inhibitors of the transforming growth factor-β (TGF-β) pathway are potentially promising antifibrotic therapies, but nonselective simultaneous inhibition of all three TGF-β homologs has safety liabilities. TGF-β1 is noncovalently bound to a latency-associated peptide that is, in turn, covalently bound to different presenting molecules within large latent complexes. The latent TGF-β-binding proteins (LTBPs) present TGF-β1 in the extracellular matrix, and TGF-β1 is presented on immune cells by two transmembrane proteins, glycoprotein A repetitions predominant (GARP) and leucine-rich repeat protein 33 (LRRC33). Here, we describe LTBP-49247, an antibody that selectively bound to and inhibited the activation of TGF-β1 presented by LTBPs but did not bind to TGF-β1 presented by GARP or LRRC33. Structural studies demonstrated that LTBP-49247 recognized an epitope on LTBP-presented TGF-β1 that is not accessible on GARP- or LRRC33-presented TGF-β1, explaining the antibody's selectivity for LTBP-complexed TGF-β1. In two rodent models of kidney fibrosis of different etiologies, LTBP-49247 attenuated fibrotic progression, indicating the central role of LTBP-presented TGF-β1 in renal fibrosis. In mice, LTBP-49247 did not have the toxic effects associated with less selective TGF-β inhibitors. These results establish the feasibility of selectively targeting LTBP-bound TGF-β1 as an approach for treating fibrosis.

CKIP-1-Loaded Cartilage-Affinitive Nanoliposomes Reverse Osteoarthritis by Restoring Chondrocyte Homeostasis

Osteoarthritis (OA) is a chronic joint disease characterized by cartilage imbalance and disruption of cartilage extracellular matrix secretion. Identifying key genes that regulate cartilage differentiation and developing effective therapeutic strategies to restore their expression is crucial. In a previous study, we observed a significant correlation between the expression of the gene encoding casein kinase-2 interacting protein-1 (CKIP-1) in the cartilage of OA patients and OA severity scores, suggesting its potential involvement in OA development. To test this hypothesis, we synthesized a chondrocyte affinity plasmid, liposomes CKIP-1, to enhance CKIP-1 expression in chondrocytes. Our results demonstrated that injection of CAP-Lipos-CKIP-1 plasmid significantly improved OA joint destruction and restored joint motor function by enhancing cartilage extracellular matrix (ECM) secretion. Histological and cytological analyses confirmed that CKIP-1 maintains altered the phosphorylation of the signal transduction molecule SMAD2/3 of the transforming growth factor-β (TGF-β) pathway by promoting the phosphorylation of the 8T, 416S sit. Taken together, this work highlights a novel approach for the precise modulation of chondrocyte phenotype from an inflammatory to a noninflammatory state for the treatment of OA and may be broadly applicable to patients suffering from other arthritic diseases.

Cyclic strain alters the transcriptional and migratory response of scleral fibroblasts to TGFβ

In glaucoma, scleral fibroblasts are exposed to IOP-associated mechanical strain and elevated TGFβ levels. These stimuli, in turn, lead to scleral remodeling. Here, we examine the scleral fibroblast migratory and transcriptional response to these stimuli to better understand mechanisms of glaucomatous scleral remodeling. Human peripapillary scleral (PPS) fibroblasts were cultured on parallel grooves, treated with TGFβ (2 ng/ml) in the presence of vehicle or TGFβ signaling inhibitors, and exposed to uniaxial strain (1 Hz, 5%, 12-24 h). Axis of cellular orientation was determined at baseline, immediately following strain, and 24 h after strain cessation with 0° being completely aligned with grooves and 90° being perpendicular. Fibroblasts migration in-line and across grooves was assessed using a scratch assay. Transcriptional profiling of TGFβ-treated fibroblasts with or without strain was performed by RT-qPCR and pERK, pSMAD2, and pSMAD3 levels were measured by immunoblot. Pre-strain alignment of TGFβ-treated cells with grooves (6.2 ± 1.5°) was reduced after strain (21.7 ± 5.3°, p < 0.0001) and restored 24 h after strain cessation (9.5 ± 2.6°). ERK, FAK, and ALK5 inhibition prevented this reduction; however, ROCK, YAP, or SMAD3 inhibition did not. TGFβ-induced myofibroblast markers were reduced by strain (αSMA, POSTN, ASPN, MLCK1). While TGFβ-induced phosphorylation of ERK and SMAD2 was unaffected by cyclic strain, SMAD3 phosphorylation was reduced (p = 0.0004). Wound healing across grooves was enhanced by ROCK and SMAD3 inhibition but not ERK or ALK5 inhibition. These results provide insight into the mechanisms by which mechanical strain alters the cellular response to TGFβ and the potential signaling pathways that underlie scleral remodeling.

Exosomes from adipose-derived mesenchymal stem cell improve diabetic wound healing and inhibit fibrosis via miR-128-1-5p/TGF-β1/Smad axis

OBJECTIVE

Difficult-to-heal wound is a prevalent and significant complication of diabetes, characterized by impaired functionality of epithelial cells such as fibroblasts. This study aims to investigate the potential mechanism of ADSC-Exos promoting diabetic wound healing by regulating fibroblast function.

MATERIALS AND METHODS

ADSC-Exos were confirmed through TEM, NTA, and Western Blot techniques. The study conducted on rat skin fibroblasts (RSFs) exposed to 33 mmol/L glucose in vitro. We used cck-8, EDU, transwell, and scratch assays to verify the proliferation and migration of RSFs. Furthermore, levels of TGF-β1 and α-SMA proteins were determined by immunofluorescence and Western Blot. RSFs were transfected with miR-128-1-5p mimics and inhibitors, followed by quantification of TGF-β1, α-SMA, Col I and Smad2/3 protein levels using Western Blot. In vivo, the effects of ADSC-Exos on diabetic wounds were assessed using digital imaging, histological staining, as well as Western Blot analysis.

RESULTS

In vitro, ADSC-Exos significantly enhanced proliferation and migration of RSFs while reducing the expression of TGF-β1 and α-SMA. In vivo, ADSC-Exos effectively promoted diabetic wound healing and mitigated scar fibrosis. Additionally, ADSC-Exos exhibited elevated levels of miR-128-1-5p, which targets TGF-β1, resulting in a notable reduction in TGF-β1, α-SMA, Col I and smad2/3 phosphorylation in RSFs.

CONCLUSION

In conclusion, our results demonstrated that ADSC-Exos promoted diabetic wound healing, and inhibited skin fibrosis by regulating miR-128-1-5p/TGF-β1/Smad signaling pathway, which provides a promising innovative treatment for diabetic wound healing.

Design and Discovery of a Potent and Selective Inhibitor of Integrin αvβ1

Selective inhibition of the RGD (Arg-Gly-Asp) integrin αvβ1 has been recently identified as an attractive therapeutic approach for the treatment of liver fibrosis given its function, target expression, and safety profile. Our identification of a non-RGD small molecule lead followed by focused, systematic changes to the core structure utilizing a crystal structure, in silico modeling, and a tractable synthetic approach resulted in the identification of a potent small molecule exhibiting a remarkable affinity for αvβ1 relative to several other integrin isoforms measured. Azabenzimidazolone 25 demonstrated antifibrotic efficacy in an in vivo rat liver fibrosis model and represents a tool compound capable of further exploring the biological consequences of selective αvβ1 inhibition.

TGF-β-Based Therapies for Treating Ocular Surface Disorders

The cornea is continuously exposed to injuries, ranging from minor scratches to deep traumas. An effective healing mechanism is crucial for the cornea to restore its structure and function following major and minor insults. Transforming Growth Factor-Beta (TGF-β), a versatile signaling molecule that coordinates various cell responses, has a central role in corneal wound healing. Upon corneal injury, TGF-β is rapidly released into the extracellular environment, triggering cell migration and proliferation, the differentiation of keratocytes into myofibroblasts, and the initiation of the repair process. TGF-β-mediated processes are essential for wound closure; however, excessive levels of TGF-β can lead to fibrosis and scarring, causing impaired vision. Three primary isoforms of TGF-β exist-TGF-β1, TGF-β2, and TGF-β3. Although TGF-β isoforms share many structural and functional similarities, they present distinct roles in corneal regeneration, which adds an additional layer of complexity to understand the role of TGF-β in corneal wound healing. Further, aberrant TGF-β activity has been linked to various corneal pathologies, such as scarring and Peter's Anomaly. Thus, understanding the molecular and cellular mechanisms by which TGF-β1-3 regulate corneal wound healing will enable the development of potential therapeutic interventions targeting the key molecule in this process. Herein, we summarize the multifaceted roles of TGF-β in corneal wound healing, dissecting its mechanisms of action and interactions with other molecules, and outline its role in corneal pathogenesis.

Lysine acetyltransferase 14 mediates TGF-β-induced fibrosis in ovarian endometrioma via co-operation with serum response factor

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.

The antiprotozoal drug nitazoxanide improves experimental liver fibrosis in mice

Nitazoxanide is an FDA-approved antiprotozoal drug. Our previous studies find that nitazoxanide and its metabolite tizoxanide affect AMPK, STAT3, and Smad2/3 signals which are involved in the pathogenesis of liver fibrosis, therefore, in the present study, we examined the effect of nitazoxanide on experimental liver fibrosis and elucidated the potential mechanisms. The in vivo experiment results showed that oral nitazoxanide (75, 100 mg·kg-1) significantly improved CCl4- and bile duct ligation-induced liver fibrosis in mice. Oral nitazoxanide activated the inhibited AMPK and inhibited the activated STAT3 in liver tissues from liver fibrosis mice. The in vitro experiment results showed that nitazoxanide and its metabolite tizoxanide activated AMPK and inhibited STAT3 signals in LX-2 cells (human hepatic stellate cells). Nitazoxanide and tizoxanide inhibited cell proliferation and collagen I expression and secretion of LX-2 cells. Nitazoxanide and tizoxanide inhibited transforming growth factor-β1 (TGF-β1)- and IL-6-induced increases of cell proliferation, collagen I expression and secretion, inhibited TGF-β1- and IL-6-induced STAT3 and Smad2/3 activation in LX-2 cells. In mouse primary hepatic stellate cells, nitazoxanide and tizoxanide also activated AMPK, inhibited STAT3 and Smad2/3 activation, inhibited cell proliferation, collagen I expression and secretion. In conclusion, nitazoxanide inhibits liver fibrosis and the underlying mechanisms involve AMPK activation, and STAT3 and Smad2/3 inhibition.

Positive and negative feedback regulation of the TGF-β1 explains two equilibrium states in skin aging

During aging, skin homeostasis is essential for maintaining appearance, as well as biological defense of the human body. In this study, we identified thrombospondin-1 (THBS1) and fibromodulin (FMOD) as positive and negative regulators, respectively, of the TGF-β1-SMAD4 axis in human skin aging, based on in vitro and in vivo omics analyses and mathematical modeling. Using transcriptomic and epigenetic analyses of senescent dermal fibroblasts, TGF-β1 was identified as the key upstream regulator. Bifurcation analysis revealed a binary high-/low-TGF-β1 switch, with THBS1 as the main controller. Computational simulation of the TGF-β1 signaling pathway indicated that THBS1 expression was sensitively regulated, whereas FMOD was regulated robustly. Results of sensitivity analysis and validation showed that inhibition of SMAD4 complex formation was a promising method to control THBS1 production and senescence. Therefore, this study demonstrated the potential of combining data-driven target discovery with mathematical approaches to determine the mechanisms underlying skin aging.

SIRT1 activation ameliorates rhesus monkey liver fibrosis by inhibiting the TGF-β/smad signaling pathway

TGF-β/Smad signaling pathway plays an important role in the pathogenesis and progression of liver fibrosis. Silent information regulator 1 (SIRT1) is a nicotinamide adenine dinucleotide (NAD+) dependent enzyme and responsible for deacetylating the proteins. Increasing numbers of reports have shown that the molecular mechanism of SIRT1 as an effective therapeutic target for liver fibrosis but the transformation is not very clear. In the present study, liver fibrotic tissues were screened by staining with Masson, hematoxylin-eosin staining (H&E) and Immunohistochemistry (IHC) for histopathological observation from the liver biopsy of seventy-seven rhesus monkey, which fixed with 4% paraformaldehyde (PFA) after treatment with high-fat diet (HFD) for two years. And the liver function was further determined by serum biochemical tests. The mRNA levels and protein expression of rat hepatic stellate (HSC-T6) cells were determined after treatment with Resveratrol (RSV) and Nicotinamide (NAM), respectively. The results showed that with the increasing of hepatic fibrosis in rhesus monkeys, the liver function impaired, and the transforming growth factor-β1 (TGF-β1), p-Smad3 (p-Smad3) and alpha-smooth muscle actin (α-SMA) was up-regulated, while SIRT1 and Smad7 were down-regulated. Moreover, when stimulated the HSC-T6 with RSV to activate SIRT1 for 6, 12, and 24 h, the results showed that RSV promoted the expression of smad7, while the expression of TGF-β1, p-Smad3 and α-SMA were inhibited. In contrast, when the cells stimulated with NAM to inhibit SIRT1 for 6, 12, and 24 h, the Smad7 expression was decreased, while TGF-β1, p-Smad3, and α-SMA expressions were increased. These results indicate that SIRT1 acts as an important protective factor for liver fibrosis, which may be attributed to inhibiting the signaling pathway of TGF-β/Smad in hepatic fibrosis of the rhesus monkey.

Role of Urinary Biomarkers (Transforming Growth Factor β1, Neutrophil Gelatinase-Associated Lipocalin, and Cystatin C) as a Prognostic Factor of Renal Outcome in the Posterior Urethral Valve

Background

The urinary biomarker response precedes the appearance of any renal structural or functional derangement. Transforming growth factor-β1 (TGF-β1), neutrophil gelatinase associated lipocalin (NGAL), and Cystatin C (CysC) can act as the early prognostic markers in posterior urethral valve (PUV) patients.

Aim

To compare the urinary levels of TGF-β1, NGAL, and CysC between PUV cases and age matched controls and to correlate these with renal structural and functional parameters.

Materials and Methods

This prospective study included children with PUV diagnosed using the standard investigations and an equal number of age-matched controls with nonurological problems. For the study subjects, the urinary samples were collected at three different time points (pre- and postoperatively at 3 and 6 months), whereas for controls, only single-voided samples were studied. The urinary levels of TGF-β1, NGAL, and CysC were estimated by the standardized techniques using the ELISA kits. Statistical methods were used to drive the comparisons between cases and controls.

Results

Fifteen children with a median age of 10 (5-48) months were enrolled in each of the two groups. The mean uTGF-β1 in the case group was significantly higher at all three time points (43.20 ± 6.13 pg/ml, 43.33 ± 11.89 pg/ml and 40.71 ± 9.01 pg/ml) as compared to the control group (29.12 ± 8.31 pg/ml) (P ≤ 0.001). The median uNGAL in the case group was also higher (17.78 ng/ml, 2.35 ng/ml and 2.536 ng/ml) as compared to the control group (1.31 ng/ml). However, the difference was significant only preoperatively (P = 0.02). The median uCysC in case group was similarly higher (0.347 μg/ml, 0.439 μg/ml, and 0.382 μg/ml) than the control group (0.243 μg/ml) (P > 0.05). Serum creatinine in the case group (0.49 mg/dl) showed no significant rise above that of control (0.24 mg/dl). A cutoff value of uTGF-β1 = 36.55 pg/ml (P < 0.001), uNGAL = 0.879 ng/ml (P = 0.02), and uCysC = 0.25 μg/ml (P = 0.22) was found to be associated with renal damage in PUV. A significant correlation was found between uNGAL and S. creatinine at 3 months (r = 0.43, P = 0.017) and 6 months (r = 0.47, P = 0.08).

Conclusion

The elevated uTGF-β1, a decline in uNGAL and an increase in uCysC suggests ongoing inflammation, improvement in hydronephrosis and a prolonged proximal tubular dysfunction in PUV patients, respectively.

Hepatotoxicity induced in rats by chronic exposure to F-53B, an emerging replacement of perfluorooctane sulfonate (PFOS)

A plethora of studies have shown the prominent hepatotoxicity caused by perfluorooctane sulfonate (PFOS), yet the research on the causality of F-53 B (an alternative for PFOS) exposure and liver toxicity, especially in mammals, is largely limited. To investigate the effects that chronic exposure to F-53 B exert on livers, in the present study, male SD rats were administrated with F-53 B in a certain dose range (0, 1, 10, 100, 1000 μg/L, eight rats per group) for 6 months via drinking water and the hepatotoxicity resulted in was explored. We reported that chronic exposure to 100 and 1000 μg/L F-53 B induced remarkable histopathological changes in liver tissues such as distinct swollen cells and portal vein congestion. In addition, the increase of cytokines IL-6, IL-2, and IL-8 upon long-term administration of F-53 B demonstrated the high level of inflammation. Moreover, F-53 B exposure was revealed to disrupt the lipid metabolism in the rat livers, mainly manifesting as the upregulation of some proteins involved in lipid synthesis and degradation, including ACC, FASN, SREBP-1c as well as ACOX1. These findings provided new evidence for the adverse effects caused by chronic exposure to F-53 B in rodents. It is crucial for industries, regulatory agencies as well as the public to remain vigilant about the adverse health effects associated with the emerging PFOS substitutes such as F-53 B. Implementation of regular monitoring and risk assessments is of great importance to alleviate environmental concerns towards PFOS alternatives exposure, and furthermore, to minimize the latent health risks to the public health.

COL1A1 proximal promoter topology regulates its transcriptional response to transforming growth factor β

OBJECTIVE

The COL1A1 proximal promoter contains two GC-rich regions and two inverted CCAAT boxes. The transcription factors Sp1 and CBF bind to the GC sequence at -122 to -115 bp and the inverted CCAAT box at -101 to -96 bp, respectively, and stimulate COL1A1 transcriptional activity.

METHODS

To further define the regulatory mechanisms controlling COL1A1 expression by Sp1 and CBF, we introduced 2, 4, 6, or 8 thymidine nucleotides (T-tracts) at position -111 bp of the COL1A1 gene promoter to increase the physical distance between these two binding sites and examined in vitro the transcriptional activities of the resulting constructs and their response to TGF-β1.`.

RESULTS

Insertion of 2 or 4 nucleotides decreased COL1A1 promoter activity by up to 70%. Furthermore, the expected increase in COL1A1 transcription in response to TGF-β1 was abolished. Computer modeling of the modified DNA structure indicated that increasing the physical distance between the Sp1 and CBF binding sites introduces a rotational change in the DNA topology that disrupts the alignment of Sp1 and CBF binding sites and likely alters protein-protein interactions among these transcription factors or their associated co-activators.

CONCLUSION

The topology of the COL1A1 proximal promoter is crucial in determining the transcriptional activity of the gene and its response to the stimulatory effects of TGF-β1.

H2S donor S-propargyl-cysteine for skin wound healing improvement via smart transdermal delivery

Hydrogen sulfide for wound healing has drawn a lot of attention recently. In this research, the S-propargyl-cysteine (SPRC), an endogenous H2S donor, was loaded on carbomer hydrogel, and a copper sheet rat burn model was developed. Pathological changes in rat skin tissue were examined using hematoxylin-eosin (HE) and Masson staining. The immunohistochemistry (IHC) staining was performed to detect the expression of Collagen I (Col I) and Collagen III (Col III). The mRNA levels of interleukin (IL)-6, Col Iα2, Col IIIα1, tissue inhibitors of metalloproteinase (TIMP)-1, matrix metalloproteinase (MMP)-9, vascular endothelial growth factor (VEGF), and transforming growth factor (TGF)-β1 were examined by quantitative real-time chain polymerase reaction. The findings demonstrated that the collagen layer was thicker in the SPRC group during the proliferative phase, SPRC hydrogel promoted VEGF expression. In the late stage of wound healing, the expression of IL-6, TIMP-1, MMP-9, and TGF-β1 was inhibited, and the Col I content was closer to that of normal tissue. These results surface that SPRC hydrogel can promote wound healing and play a positive role in reducing scar formation. Our results imply that SPRC can facilitate wound healing and play a positive role in reducing scar formation.

Integrins in biliary injury and fibrosis

PURPOSE OF REVIEW

Current treatment options for cholangiopathies are severely limited and there is thus a critical need to identify and develop therapies. This review discusses the role of integrins in biliary injury and fibrosis and their potential as therapeutic targets.

RECENT FINDINGS

There are a diverse set of roles that integrins play in biliary injury and fibrosis. Some integrins activate TGF-β signaling or are involved in sensing of the extracellular matrix, making them attractive targets for biliary fibrosis. In recent work, autoantibodies to α v β 6 were identified in patients with PSC, supporting the relevance of this integrin in the disease. In addition, a role for α 2 β 1 in cyst formation was identified in a mouse model of polycystic liver disease. Leukocyte integrins (e.g. α E β 7 and α 4 β 7 ) contribute to lymphocyte trafficking, making them potential targets for biliary inflammation; however, this has not yet translated to the clinic.

SUMMARY

While all members of the same family of proteins, integrins have diverse roles in the pathogenesis of biliary disease. Targeting one or multiple of these integrins may slow or halt the progression of biliary injury and fibrosis by simultaneously impacting different pathologic cells and processes.

Antifibrotic effects of vitamin D3 on human lung fibroblasts derived from patients with idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal interstitial lung disease. Up to now, no treatment can stop the progression of IPF. Vitamin D3 (VD) reduces experimental lung fibrosis in murine models and depletion of vitamin D3 might be associated with the reduced survival of patients with IPF. In this context, we determined if VD can prevent the pro-fibrotic functions of human lung fibroblasts (HLFs) isolated from patients with IPF. IPF and control HLFs were derived from surgical lung biopsies collected from patients with IPF or with primary lung cancer, respectively. VD (3-100 nM) markedly reduced the basal and PDGF-induced proliferation of HLFs. VD also altered cell cycle by increasing the percentage of IPF HLFs arrested in the G0/G1 phase, and by downregulating the expression of various cell cycle regulatory proteins. In addition, VD barely prevented the TGF-β1-induced differentiation in HLFs. At 100 nM, VD slightly reduced the expression of the pro-fibrotic marker α-smooth muscle actin, and had no effect on fibronectin and collagen-1 expression. In contrast, 100 nM VD strongly inhibited the aerobic glycolytic metabolism induced by TGF- β1. Finally, VD reduced both the secretion of lactate, the levels of lactate deshydrogenase mRNA and the activity of intracellular LDH in IPF HLFs. In conclusion, our study shows that VD reduced pro-fibrotic functions of HLFs. These findings suggest that it might be interesting to assess the potential clinical benefits of vitamin D supplementation in patients with IPF, especially on lung function decline.

Deciphering the fibrotic process: mechanism of chronic radiation skin injury fibrosis

This review explores the mechanisms of chronic radiation-induced skin injury fibrosis, focusing on the transition from acute radiation damage to a chronic fibrotic state. It reviewed the cellular and molecular responses of the skin to radiation, highlighting the role of myofibroblasts and the significant impact of Transforming Growth Factor-beta (TGF-β) in promoting fibroblast-to-myofibroblast transformation. The review delves into the epigenetic regulation of fibrotic gene expression, the contribution of extracellular matrix proteins to the fibrotic microenvironment, and the regulation of the immune system in the context of fibrosis. Additionally, it discusses the potential of biomaterials and artificial intelligence in medical research to advance the understanding and treatment of radiation-induced skin fibrosis, suggesting future directions involving bioinformatics and personalized therapeutic strategies to enhance patient quality of life.

TGF-β signaling promotes desmoid tumor formation via CSRP2 upregulation

Desmoid tumors (DTs), also called desmoid-type fibromatoses, are locally aggressive tumors of mesenchymal origin. In the present study, we developed a novel mouse model of DTs by inducing a local mutation in the Ctnnb1 gene, encoding β-catenin in PDGFRA-positive stromal cells, by subcutaneous injection of 4-hydroxy-tamoxifen. Tumors in this model resembled histologically clinical samples from DT patients and showed strong phosphorylation of nuclear SMAD2. Knockout of SMAD4 in the model significantly suppressed tumor growth. Proteomic analysis revealed that SMAD4 knockout reduced the level of Cysteine-and-Glycine-Rich Protein 2 (CSRP2) in DTs, and treatment of DT-derived cells with a TGF-β receptor inhibitor reduced CSRP2 RNA levels. Knockdown of CSRP2 in DT cells significantly suppressed their proliferation. These results indicate that the TGF-β/CSRP2 axis is a potential therapeutic target for DTs downstream of TGF-β signaling.

Therapeutic Potential and Mechanisms of Rosmarinic Acid and the Extracts of Lamiaceae Plants for the Treatment of Fibrosis of Various Organs

Fibrosis, which causes structural hardening and functional degeneration in various organs, is characterized by the excessive production and accumulation of connective tissue containing collagen, alpha-smooth muscle actin (α-SMA), etc. In traditional medicine, extracts of medicinal plants or herbal prescriptions have been used to treat various fibrotic diseases. The purpose of this narrative review is to discuss the antifibrotic effects of rosmarinic acid (RA) and plant extracts that contain RA, as observed in various experimental models. RA, as well as the extracts of Glechoma hederacea, Melissa officinalis, Elsholtzia ciliata, Lycopus lucidus, Ocimum basilicum, Prunella vulgaris, Salvia rosmarinus (Rosmarinus officinalis), Salvia miltiorrhiza, and Perilla frutescens, have been shown to attenuate fibrosis of the liver, kidneys, heart, lungs, and abdomen in experimental animal models. Their antifibrotic effects were associated with the attenuation of oxidative stress, inflammation, cell activation, epithelial-mesenchymal transition, and fibrogenic gene expression. RA treatment activated peroxisomal proliferator-activated receptor gamma (PPARγ), 5' AMP-activated protein kinase (AMPK), and nuclear factor erythroid 2-related factor 2 (NRF2) while suppressing the transforming growth factor beta (TGF-β) and Wnt signaling pathways. Interestingly, most plants that are reported to contain RA and exhibit antifibrotic activity belong to the family Lamiaceae. This suggests that RA is an active ingredient for the antifibrotic effect of Lamiaceae plants and that these plants are a useful source of RA. In conclusion, accumulating scientific evidence supports the effectiveness of RA and Lamiaceae plant extracts in alleviating fibrosis and maintaining the structural architecture and normal functions of various organs under pathological conditions.

Insights into How Plant-Derived Extracts and Compounds Can Help in the Prevention and Treatment of Keloid Disease: Established and Emerging Therapeutic Targets

Keloid is a disease in which fibroblasts abnormally proliferate and synthesize excessive amounts of extracellular matrix, including collagen and fibronectin, during the healing process of skin wounds, causing larger scars that exceed the boundaries of the original wound. Currently, surgical excision, cryotherapy, radiation, laser treatment, photodynamic therapy, pressure therapy, silicone gel sheeting, and pharmacotherapy are used alone or in combinations to treat this disease, but the outcomes are usually unsatisfactory. The purpose of this review is to examine whether natural products can help treat keloid disease. I introduce well-established therapeutic targets for this disease and various other emerging therapeutic targets that have been proposed based on the phenotypic difference between keloid-derived fibroblasts (KFs) and normal epidermal fibroblasts (NFs). We then present recent studies on the biological effects of various plant-derived extracts and compounds on KFs and NFs. Associated ex vivo, in vivo, and clinical studies are also presented. Finally, we discuss the mechanisms of action of the plant-derived extracts and compounds, the pros and cons, and the future tasks for natural product-based therapy for keloid disease, as compared with existing other therapies. Extracts of Astragalus membranaceus, Salvia miltiorrhiza, Aneilema keisak, Galla Chinensis, Lycium chinense, Physalis angulate, Allium sepa, and Camellia sinensis appear to modulate cell proliferation, migration, and/or extracellular matrix (ECM) production in KFs, supporting their therapeutic potential. Various phenolic compounds, terpenoids, alkaloids, and other plant-derived compounds could modulate different cell signaling pathways associated with the pathogenesis of keloids. For now, many studies are limited to in vitro experiments; additional research and development are needed to proceed to clinical trials. Many emerging therapeutic targets could accelerate the discovery of plant-derived substances for the prevention and treatment of keloid disease. I hope that this review will bridge past, present, and future research on this subject and provide insight into new therapeutic targets and pharmaceuticals, aiming for effective keloid treatment.

Fibrous Remodeling in Eosinophilic Esophagitis: Clinical Facts and Pathophysiological Uncertainties

Eosinophilic esophagitis (EoE) is a chronic, progressive, type 2 inflammatory disease with increasing global prevalence. An eosinophil-predominant inflammation that permeates the epithelium and deeper esophageal layers characterizes the disease. Several cytokines, mainly derived from inflammatory T-helper 2 (Th2) cells and epithelial cells, are involved in perpetuating inflammatory responses by increasing surface permeability and promoting tissue remodeling characterized by epithelial-mesenchymal transition (EMT) and collagen deposition. This leads to esophageal strictures and narrow caliber esophagi, which are proportional a patient's age and untreated disease length. Pathophysiological mechanisms leading to EoE have been described in recent years, and transforming growth factor beta (TGF)-beta have been involved in fibrotic phenomena in EoE. However, evidence on the dependence of these phenomena on TGF-beta is scarce and contradictory. This review provides state-of-the art knowledge on intimate mechanisms of esophageal fibrosis in EoE and its clinical consequences.

Cellular Transdifferentiation: A Crucial Mechanism of Fibrosis in Systemic Sclerosis

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.

Chitosan and α-cellulose-based mupirocin topical film-forming spray: Optimization, in vitro characterization, antimicrobial studies and wound healing activity

The study aimed to develop a biopolymer-based mupirocin film-forming spray (MUP-FFS) for wound healing using chitosan and α-cellulose. MUP-FFS formulation was optimized by box-Behnken design, wherein the amount of chitosan, glycerol, and microfluidizer cycles showed a significant effect on the drying time and sprayability, but drug release remained unaffected. The optimized MUP-FFS formulation prepared by 13 microfluidizer cycles containing chitosan (0.125 %), glycerol (2.76 %) was quickly sprayable with 235 s drying time. The viscosity, spray uniformity and occlusive potential were found optimum for MUP-FFS. MUP-FFS released 98.066 % of MUP, 2-fold and 4-fold greater than the marketed ointment and MUP-API. The transmission electron microscopy displayed a homogeneous fibrous network, and scanning electron microphotographs showed uniform drug distribution on the MUP-film surface. The antimicrobial study revealed the efficacy of MUP-FFS against S.aureus and E.coli, wherein the former was more susceptible to formulation than the later. MUP-FFS indicated better wound contraction and healing than other groups on 7th and 14th day in rats. On Day-21, MUP-FFS could regress TGF-β1 to a normal level similar to the marketed formulation, which was also reflected in histopathological observations. Therefore, MUP-FFS can be a treatment option for chronic wounds, applied without touch and with minimal mechanical pressure.

Antioxidant therapy against TGF-β/SMAD pathway involved in organ fibrosis

Fibrosis refers to excessive build-up of scar tissue and extracellular matrix components in different organs. In recent years, it has been revealed that different cytokines and chemokines, especially Transforming growth factor beta (TGF-β) is involved in the pathogenesis of fibrosis. It has been shown that TGF-β is upregulated in fibrotic tissues, and contributes to fibrosis by mediating pathways that are related to matrix preservation and fibroblasts differentiation. There is no doubt that antioxidants protect against different inflammatory conditions by reversing the effects of nitrogen, oxygen and sulfur-based reactive elements. Oxidative stress has a direct impact on chronic inflammation, and as results, prolonged inflammation ultimately results in fibrosis. Different types of antioxidants, in the forms of vitamins, natural compounds or synthetic ones, have been proven to be beneficial in the protection against fibrotic conditions both in vitro and in vivo. In this study, we reviewed the role of different compounds with antioxidant activity in induction or inhibition of TGF-β/SMAD signalling pathway, with regard to different fibrotic conditions such as gastro-intestinal fibrosis, cardiac fibrosis, pulmonary fibrosis, skin fibrosis, renal fibrosis and also some rare cases of fibrosis, both in animal models and cell lines.

Inhibition of TGFβ1 activation prevents radiation-induced lung fibrosis

BACKGROUND

Radiotherapy is the main treatment modality for thoracic tumours, but it may induce pulmonary fibrosis. Currently, the pathogenesis of radiation-induced pulmonary fibrosis (RIPF) is unclear, and effective treatments are lacking. Transforming growth factor beta 1 (TGFβ1) plays a central role in RIPF. We found that activated TGFβ1 had better performance for radiation pneumonitis (RP) risk prediction by detecting activated and total TGFβ1 levels in patient serum. αv integrin plays key roles in TGFβ1 activation, but the role of αv integrin-mediated TGFβ1 activation in RIPF is unclear. Here, we investigated the role of αv integrin-mediated TGFβ1 activation in RIPF and the application of the integrin antagonist cilengitide to prevent RIPF.

METHODS

ItgavloxP/loxP ;Pdgfrb-Cre mice were generated by conditionally knocking out Itgav in myofibroblasts, and wild-type mice were treated with cilengitide or placebo. All mice received 16 Gy of radiation or underwent a sham radiation procedure. Lung fibrosis was measured by a modified Ashcroft score and microcomputed tomography (CT). An enzyme-linked immunosorbent assay (ELISA) was used to measure the serum TGFβ1 concentration, and total Smad2/3 and p-Smad2/3 levels were determined via Western blotting.

RESULTS

Conditional Itgav knockout significantly attenuated RIPF (p < .01). Hounsfield units (HUs) in the lungs were reduced in the knockout mice compared with the control mice (p < .001). Conditional Itgav knockout decreased active TGFβ1 secretion and inhibited fibroblast p-Smad2/3 expression. Exogenous active TGFβ1, but not latent TGFβ1, reversed these reductions. Furthermore, cilengitide treatment elicited similar results and prevented RIPF.

CONCLUSIONS

The present study revealed that conditional Itgav knockout and cilengitide treatment both significantly attenuated RIPF in mice by inhibiting αv integrin-mediated TGFβ1 activation.

HIGHLIGHTS

Activated TGFβ1 has a superior capacity in predicting radiation pneumonitis (RP) risk and plays a vital role in the development of radiation-induced pulmonary fibrosis (RIPF). Conditional knock out Itgav in myofibroblasts prevented mice from developing RIPF. Cilengitide alleviated the development of RIPF by inhibiting αv integrin-mediated TGFβ1 activation and may be used in targeted approaches for preventing RIPF.

Inflammation-Associated Cytotoxic Agents in Tumorigenesis

Chronic inflammatory processes are related to all stages of tumorigenesis. As inflammation is closely associated with the activation and release of different cytotoxic agents, the interplay between cytotoxic agents and antagonizing principles is highlighted in this review to address the question of how tumor cells overcome the enhanced values of cytotoxic agents in tumors. In tumor cells, the enhanced formation of mitochondrial-derived reactive species and elevated values of iron ions and free heme are antagonized by an overexpression of enzymes and proteins, contributing to the antioxidative defense and maintenance of redox homeostasis. Through these mechanisms, tumor cells can even survive additional stress caused by radio- and chemotherapy. Through the secretion of active agents from tumor cells, immune cells are suppressed in the tumor microenvironment and an enhanced formation of extracellular matrix components is induced. Different oxidant- and protease-based cytotoxic agents are involved in tumor-mediated immunosuppression, tumor growth, tumor cell invasion, and metastasis. Considering the special metabolic conditions in tumors, the main focus here was directed on the disturbed balance between the cytotoxic agents and protective mechanisms in late-stage tumors. This knowledge is mandatory for the implementation of novel anti-cancerous therapeutic approaches.

PGF2α signaling drives fibrotic remodeling and fibroblast population dynamics in mice

Idiopathic pulmonary fibrosis (IPF) is a chronic parenchymal lung disease characterized by repetitive alveolar cell injury, myofibroblast proliferation, and excessive extracellular matrix deposition for which unmet need persists for effective therapeutics. The bioactive eicosanoid, prostaglandin F2α, and its cognate receptor FPr (Ptgfr) are implicated as a TGF-β1-independent signaling hub for IPF. To assess this, we leveraged our published murine PF model (IER-SftpcI73T) expressing a disease-associated missense mutation in the surfactant protein C (Sftpc) gene. Tamoxifen-treated IER-SftpcI73T mice developed an early multiphasic alveolitis and transition to spontaneous fibrotic remodeling by 28 days. IER-SftpcI73T mice crossed to a Ptgfr-null (FPr-/-) line showed attenuated weight loss and gene dosage-dependent rescue of mortality compared with FPr+/+ cohorts. IER-SftpcI73T/FPr-/- mice also showed reductions in multiple fibrotic endpoints for which administration of nintedanib was not additive. Single-cell RNA-Seq, pseudotime analysis, and in vitro assays demonstrated Ptgfr expression predominantly within adventitial fibroblasts, which were reprogrammed to an "inflammatory/transitional" cell state in a PGF2α /FPr-dependent manner. Collectively, the findings provide evidence for a role for PGF2α signaling in IPF, mechanistically identify a susceptible fibroblast subpopulation, and establish a benchmark effect size for disruption of this pathway in mitigating fibrotic lung remodeling.

Machine Learning and Single-Cell Analysis Identify Molecular Features of IPF-Associated Fibroblast Subtypes and Their Implications on IPF Prognosis

Idiopathic pulmonary fibrosis (IPF) is a devastating lung disease of unknown cause, and the involvement of fibroblasts in its pathogenesis is well recognized. However, a comprehensive understanding of fibroblasts' heterogeneity, their molecular characteristics, and their clinical relevance in IPF is lacking. In this study, we aimed to systematically classify fibroblast populations, uncover the molecular and biological features of fibroblast subtypes in fibrotic lung tissue, and establish an IPF-associated, fibroblast-related predictive model for IPF. Herein, a meticulous analysis of scRNA-seq data obtained from lung tissues of both normal and IPF patients was conducted to identify fibroblast subpopulations in fibrotic lung tissues. In addition, hdWGCNA was utilized to identify co-expressed gene modules associated with IPF-related fibroblasts. Furthermore, we explored the prognostic utility of signature genes for these IPF-related fibroblast subtypes using a machine learning-based approach. Two predominant fibroblast subpopulations, termed IPF-related fibroblasts, were identified in fibrotic lung tissues. Additionally, we identified co-expressed gene modules that are closely associated with IPF-fibroblasts by utilizing hdWGCNA. We identified gene signatures that hold promise as prognostic markers in IPF. Moreover, we constructed a predictive model specifically focused on IPF-fibroblasts which can be utilized to assess disease prognosis in IPF patients. These findings have the potential to improve disease prediction and facilitate targeted interventions for patients with IPF.

MircroRNA-92b as a negative regulator of the TGF-β signaling by targeting the type I receptor

Transforming growth factor β1 (TGFβ1) has been identified as a major pathogenic factor underlying the development of chronic kidney disease (CKD). This study investigated the role of miR-92b-3p in the progression of renal fibrosis in unilateral ureteral occlusion (UUO) and unilateral ischemia-reperfusion injury (uIRI) mouse models, as well as explored its underlying mechanisms in human proximal tubular epithelial (HK2) cells. We found that renal fibrosis increased in UUO mice after miR-92b knockout, while it reduced in miR-92b overexpressing mice. MiR-92b knockout aggravated renal fibrosis in uIRI mice. RNA-sequencing analysis, the luciferase reporter assay, qPCR analysis, and western blotting confirmed that miR-92b-3p directly targeted TGF-β receptor 1, thereby ameliorating renal fibrosis by suppressing the TGF-β signaling pathway. Furthermore, we found that TGF-β suppressed miR-92b transcription through Snail family transcriptional repressors 1 and 2. Our results suggest that miR-92b-3p may serve as a novel therapeutic for mitigating fibrosis in CKD.

NXC736 Attenuates Radiation-Induced Lung Fibrosis via Regulating NLRP3/IL-1β Signaling Pathway

Radiation-induced lung fibrosis (RILF) is a common complication of radiotherapy in lung cancer. However, to date no effective treatment has been developed for this condition. NXC736 is a novel small-molecule compound that inhibits NLRP3, but its effect on RILF is unknown. NLRP3 activation is an important trigger for the development of RILF. Thus, we aimed to evaluate the therapeutic effect of NXC736 on lung fibrosis inhibition using a RILF animal model and to elucidate its molecular signaling pathway. The left lungs of mice were irradiated with a single dose of 75 Gy. We observed that NXC736 treatment inhibited collagen deposition and inflammatory cell infiltration in irradiated mouse lung tissues. The damaged lung volume, evaluated by magnetic resonance imaging, was lower in NXC736-treated mice than in irradiated mice. NXC736-treated mice exhibited significant changes in lung function parameters. NXC736 inhibited inflammasome activation by interfering with the NLRP3-ASC-cleaved caspase-1 interaction, thereby reducing the expression of IL-1β and blocking the fibrotic pathway. In addition, NXC736 treatment reduced the expression of epithelial-mesenchymal transition markers such as α-SMA, vimentin, and twist by blocking the Smad 2,3,4 signaling pathway. These data suggested that NXC736 is a potent therapeutic agent against RILF.

Extracellular matrix turnover in salivary gland disorders and regenerative therapies: Obstacles and opportunities

Salivary gland (SG) extracellular matrix (ECM) has a major influence on tissue development, homeostasis, and tissue regeneration after injury. During aging, disease, and physical insult, normal remodeling of the SG microenvironment (i.e. ECM) becomes dysregulated, leading to alterations in matrix composition which disrupt tissue architecture/structure, alter cell activity, and negatively impact gland function. Matrix metalloproteinases (MMPs) are a large and diverse family of metalloendopeptidases which play a major role in matrix degradation and are intimately involved in regulating development and cell function; dysregulation of these enzymes leads to the production of a fibrotic matrix. In the SG this altered fibrotic ECM (or cell microenvironment) negatively impacts normal cell function and the effectiveness of gene and stem cell therapies which serve as a foundation for many SG regenerative therapies. For this reason, prospective regenerative strategies should prioritize the maintenance and/or restoration of a healthy SG ECM. Mesenchymal stem cells (MSCs) have great potential for mitigating damage to the SG microenvironment by ameliorating inflammation, reducing fibrosis, and repairing the damaged milieu of extracellular regulatory cues, including the matrix. This review addresses our current understanding of the impact of aging and disease on the SG microenvironment and suggests critical deficiencies and opportunities in ECM-targeted therapeutic interventions.

Extracellular matrix turnover: phytochemicals target and modulate the dual role of matrix metalloproteinases (MMPs) in liver fibrosis

Extracellular matrix (ECM) resolution by matrix metalloproteinases (MMPs) is a well-documented mechanism. MMPs play a dual and complex role in modulating ECM degradation at different stages of liver fibrosis, depending on the timing and levels of their expression. Increased MMP-1 combats disease progression by cleaving the fibrillar ECM. Activated hepatic stellate cells (HSCs) increase expression of MMP-2, -9, and -13 in different chemicals-induced animal models, which may alleviate or worsen disease progression based on animal models and the stage of liver fibrosis. In the early stage, elevated expression of certain MMPs may damage surrounding tissue and activate HSCs, promoting fibrosis progression. At the later stage, downregulation of MMPs can facilitate ECM accumulation and disease progression. A number of phytochemicals modulate MMP activity and ECM turnover, alleviating disease progression. However, the effects of phytochemicals on the expression of different MMPs are variable and may depend on the disease models and stage, and the dosage, timing and duration of phytochemicals used in each study. Here, we review the most recent advances in the role of MMPs in the effects of phytochemicals on liver fibrogenesis, which indicates that further studies are warranted to confirm and define the potential clinical efficacy of these phytochemicals.

Tyrosine kinase receptor B attenuates liver fibrosis by inhibiting TGF-β/SMAD signaling

BACKGROUND AND AIMS

Liver fibrosis is a leading indicator for increased mortality and long-term comorbidity in NASH. Activation of HSCs and excessive extracellular matrix production are the hallmarks of liver fibrogenesis. Tyrosine kinase receptor (TrkB) is a multifunctional receptor that participates in neurodegenerative disorders. However, paucity of literature is available about TrkB function in liver fibrosis. Herein, the regulatory network and therapeutic potential of TrkB were explored in the progression of hepatic fibrosis.

METHODS AND RESULTS

The protein level of TrkB was decreased in mouse models of CDAHFD feeding or carbon tetrachloride-induced hepatic fibrosis. TrkB suppressed TGF-β-stimulated proliferation and activation of HSCs in 3-dimensional liver spheroids and significantly repressed TGF-β/SMAD signaling pathway either in HSCs or in hepatocytes. The cytokine, TGF-β, boosted Nedd4 family interacting protein-1 (Ndfip1) expression, promoting the ubiquitination and degradation of TrkB through E3 ligase Nedd4-2. Moreover, carbon tetrachloride intoxication-induced hepatic fibrosis in mouse models was reduced by adeno-associated virus vector serotype 6 (AAV6)-mediated TrkB overexpression in HSCs. In addition, in murine models of CDAHFD feeding and Gubra-Amylin NASH (GAN), fibrogenesis was reduced by adeno-associated virus vector serotype 8 (AAV8)-mediated TrkB overexpression in hepatocytes.

CONCLUSION

TGF-β stimulated TrkB degradation through E3 ligase Nedd4-2 in HSCs. TrkB overexpression inhibited the activation of TGF-β/SMAD signaling and alleviated the hepatic fibrosis both in vitro and in vivo . These findings demonstrate that TrkB could be a significant suppressor of hepatic fibrosis and confer a potential therapeutic target in hepatic fibrosis.

Simvastatin Attenuates Areca Nut Extract-Induced Subdermal Fibrosis in Mice by Targeting TGF-β Signaling Pathways

Oral submucous fibrosis (OSMF) is a chronic inflammatory disease and a potentially malignant oral disorder, characterized by fibrosis of the oral mucosa. TGF-β signaling pathways have been implicated in the development of OSMF, with areca nut extract (ANE) contributing to the disease progression. Simvastatin, a statin drug, has demonstrated anti-fibrotic properties in various fibrotic conditions. However, its therapeutic potential in treating OSMF remains unclear. In this study, 8-week-old male BALB/c mice were randomly divided into three groups based on different time points. Each mouse was then treated with four different drug formulations. Post-treatment, specimens were collected for histopathological examination and staining to assess skin thickness, fibrosis, and collagen deposition. ANE treatment alone significantly increased skin thickness and collagen deposition compared to the control group after the 4-week time point. The combined administration of ANE and simvastatin, resulted in a notable reduction in skin thickness and collagen deposition. Western blot analysis revealed that simvastatin effectively suppressed the expression of fibrosis-related proteins, including CTGF, and α-SMA, in ANE-induced subdermal fibrosis. These results suggest that simvastatin has potential therapeutic effects on ANE-induced subdermal fibrosis, providing a foundation for future studies and possible clinical applications.

Mechanisms of Regeneration and Fibrosis in the Endometrium

The uterine lining (endometrium) regenerates repeatedly over the life span as part of its normal physiology. Substantial portions of the endometrium are shed during childbirth (parturition) and, in some species, menstruation, but the tissue is rapidly rebuilt without scarring, rendering it a powerful model of regeneration in mammals. Nonetheless, following some assaults, including medical procedures and infections, the endometrium fails to regenerate and instead forms scars that may interfere with normal endometrial function and contribute to infertility. Thus, the endometrium provides an exceptional platform to answer a central question of regenerative medicine: Why do some systems regenerate while others scar? Here, we review our current understanding of diverse endometrial disruption events in humans, nonhuman primates, and rodents, and the associated mechanisms of regenerative success and failure. Elucidating the determinants of these disparate repair processes promises insights into fundamental mechanisms of mammalian regeneration with substantial implications for reproductive health.

Time course of western diet (WD) induced nonalcoholic steatohepatitis (NASH) in female and male Ldlr-/- mice

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a global health problem. Identification of factors contributing to the onset and progression of NAFLD have the potential to direct novel strategies to combat NAFLD.

METHODS

We examined the time course of western diet (WD)-induced NAFLD and its progression to nonalcoholic steatohepatitis (NASH) in age-matched female and male Ldlr-/- mice, with time-points at 1, 4, 8, 20 and 40 weeks on the WD. Controls included Ldlr-/- mice maintained on a purified low-fat diet (LFD) for 1 and 40 weeks. The approach included quantitation of anthropometric, plasma and liver markers of disease, plus hepatic histology, lipids, oxylipins, gene expression and selected metabolites.

RESULTS

One week of feeding the WD caused a significant reduction in hepatic essential fatty acids (EFAs: 18:2, ω6, 18:3, ω3) which preceded the decline in many C20-22 ω3 and ω6 polyunsaturated fatty acids (PUFA) and PUFA-derived oxylipins after 4 weeks on the WD. In addition, expression of hepatic inflammation markers (CD40, CD44, Mcp1, Nlrp3, TLR2, TLR4, Trem2) increased significantly in both female & male mice after one week on the WD. These markers continued to increase over the 40-week WD feeding study. WD effects on hepatic EFA and inflammation preceded all significant WD-induced changes in body weight, insulin resistance (HOMA-IR), oxidative stress status (GSH/GSSG ratio) and histological and gene expression markers of macrosteatosis, extracellular matrix remodeling and fibrosis.

CONCLUSIONS

Our findings establish that feeding Ldlr-/- mice the WD rapidly lowered hepatic EFAs and induced key inflammatory markers linked to NASH. Since EFAs have an established role in inflammation and hepatic inflammation plays a major role in NASH, we suggest that early clinical assessment of EFA status and correcting EFA deficiencies may be useful in reducing NASH severity.

Treatable Traits in Systemic Sclerosis

Systemic sclerosis (SSc) is a chronic systemic disease within the spectrum of connective tissue diseases, specifically characterized by vascular abnormalities and inflammatory and fibrotic involvement of the skin and internal organs resulting in high morbidity and mortality. The clinical phenotype of SSc is heterogeneous, and serum autoantibodies together with the extent of skin involvement have a predictive value in the risk stratification. Current recommendations include an organ-based management according to the predominant involvement with only limited individual factors included in the treatment algorithm. Similar to what has been proposed for other chronic diseases, we hypothesize that a "treatable trait" approach based on relevant phenotypes and endotypes could address the unmet needs in SSc stratification and treatment to maximize the outcomes. We provide herein a comprehensive review and a critical discussion of the literature regarding potential treatable traits in SSc, focusing on established and candidate biomarkers, with the purpose of setting the bases for a precision medicine-based approach. The discussion, structured based on the organ involvement, allows to conjugate the pathogenetic mechanisms of tissue injury with the proposed predictors, particularly autoantibodies and other serum biomarkers. Ultimately, we are convinced that precision medicine is the ideal guide to manage a complex condition such as SSc for which available treatments are largely unsatisfactory.

Alogliptin exhibits multifaceted effects in thioacetamide-insulted rats: A novel approach to combating hepatic inflammation and fibrogenesis

Hepatic fibrosis arising from chronic liver injury is characterized by dysregulated healing, including hepatic stellate cell activation and excessive deposition of extracellular matrix proteins. Administration of the hepatotoxin thioacetamide (TAA) induces liver injury coupled to fibrogenesis in rodents, mimicking aspects of human disease. Alogliptin is a highly selective inhibitor of dipeptidyl peptidase-4 with purported antifibrotic actions. We investigated the protective effects of alogliptin against TAA-mediated hepatic fibrosis in rats. Adult male Sprague-Dawley rats received intraperitoneal injections of TAA (150 mg/kg) twice weekly for 6 weeks to induce liver fibrosis. A subset of rats also received daily oral alogliptin (20 mg/kg). At 6 weeks, liver injury and fibrosis were assessed by histology, hydroxyproline content, serum liver enzymes, inflammatory cytokines, oxidative stress markers, and genes related to inflammation, apoptosis, and fibrosis. TAA elicited necroinflammation, oxidative stress, upregulation of pro-fibrogenic mediators, increased hydroxyproline content, and excessive collagen deposition, indicating hepatic fibrosis. The administration of Alogliptin led to notable enhancements in liver histology, an extension in survival time, a decrease in hydroxyproline levels and the expression of fibrogenic genes, a reduction in inflammatory cytokines and oxidative stress, and mitigation of hepatocellular apoptosis in rats subjected to TAA treatment. Alogliptin displayed potent antifibrotic, antioxidant, and hepatoprotective properties in this model of toxic liver damage, likely by impeding NFκB while enhanced Nrf2 DNA binding activity which together modulate oxidative stress, inflammation, myofibroblast activation, and apoptosis. These results highlight the potential therapeutic value of alogliptin offering hope for improved treatment of hepatic fibrosis.

Total sesquiterpenoids from Eupatorium lindleyanum DC. attenuate bleomycin-induced lung fibrosis by suppressing myofibroblast transition

Eupatorium lindleyanum DC. has been used as a functional food in China for a long time. However, the antifibrotic activity of total sesquiterpenoids from Eupatorium lindleyanum DC. (TS-EL) is still unknown. In this study, we discovered that TS-EL reduced the increase in α-smooth muscle actin (α-SMA), type I collagen and fibronectin content, the formation of cell filaments and collagen gel contraction in transforming growth factor-β1-stimulated human lung fibroblasts. Intriguingly, TS-EL did not change the phosphorylation of Smad2/3 and Erk1/2. TS-EL decreased the levels of serum response factor (SRF), a critical transcription factor of α-SMA, and SRF knockdown alleviated the transition of lung myofibroblasts. Furthermore, TS-EL significantly attenuated bleomycin (BLM)-induced lung pathology and collagen deposition and reduced the levels of two profibrotic markers, total lung hydroxyproline and α-SMA. TS-EL also decreased the levels of SRF protein expression in BLM-induced mice. These results suggested that TS-EL attenuates pulmonary fibrosis by inhibiting myofibroblast transition via the downregulation of SRF.

Targeting collagen homeostasis for the treatment of liver fibrosis: Opportunities and challenges

Liver fibrosis is an excessive production, aberrant deposition, and deficit degradation of extracellular matrix (ECM). Patients with unresolved fibrosis ultimately undergo end-stage liver diseases. To date, the effective and safe strategy to cease fibrosis progression remains an unmet clinical need. Since collagens are the most abundant ECM protein which play an essential role in fibrogenesis, the suitable regulation of collagen homeostasis could be an effective strategy for the treatment of liver fibrosis. Therefore, this review provides a brief overview on the dysregulation of ECM homeostasis, focusing on collagens, in the pathogenesis of liver fibrosis. Most importantly, promising therapeutic mechanisms related to biosynthesis, deposition and extracellular interactions, and degradation of collagens, together with preclinical and clinical antifibrotic evidence of drugs affecting each target are orderly criticized. In addition, challenges for targeting collagen homeostasis in the treatment of liver fibrosis are discussed.

Mechanisms of organ fibrosis: Emerging concepts and implications for novel treatment strategies

Fibrosis, or tissue scarring, develops as a pathological deviation from the physiological wound healing response and can occur in various organs such as the heart, lung, liver, kidney, skin, and bone marrow. Organ fibrosis significantly contributes to global morbidity and mortality. A broad spectrum of etiologies can cause fibrosis, including acute and chronic ischemia, hypertension, chronic viral infection (e.g., viral hepatitis), environmental exposure (e.g., pneumoconiosis, alcohol, nutrition, smoking) and genetic diseases (e.g., cystic fibrosis, alpha-1-antitrypsin deficiency). Common mechanisms across organs and disease etiologies involve a sustained injury to parenchymal cells that triggers a wound healing response, which becomes deregulated in the disease process. A transformation of resting fibroblasts into myofibroblasts with excessive extracellular matrix production constitutes the hallmark of disease, however, multiple other cell types such as immune cells, predominantly monocytes/macrophages, endothelial cells, and parenchymal cells form a complex network of profibrotic cellular crosstalk. Across organs, leading mediators include growth factors like transforming growth factor-β and platelet-derived growth factor, cytokines like interleukin-10, interleukin-13, interleukin-17, and danger-associated molecular patterns. More recently, insights into fibrosis regression and resolution of chronic conditions have deepened our understanding of beneficial, protective effects of immune cells, soluble mediators and intracellular signaling. Further in-depth insights into the mechanisms of fibrogenesis can provide the rationale for therapeutic interventions and the development of targeted antifibrotic agents. This review gives insight into shared responses and cellular mechanisms across organs and etiologies, aiming to paint a comprehensive picture of fibrotic diseases in both experimental settings and in human pathology.

Human Macrophages Polarized by Interaction with Apoptotic Cells Produce Fibrosis-Associated Mediators and Enhance Pro-Fibrotic Activity of Dermal Fibroblasts In Vitro

Apoptosis and subsequent removal of dead cells are an essential part of wound healing. Macrophages phagocytize apoptotic cells (efferocytosis) and contribute to the resolution of inflammation. However, their participation in fibrogenesis and the mechanisms of influence on this process remain unclear. In the present study, we focused on the fibrogenic properties of human monocyte-derived macrophages polarized in the M2 direction by interaction with apoptotic cells. We studied their influence on the proliferation ([3H]-thymidine incorporation), differentiation (by the expression of α-SMA, a myofibroblast marker) and collagen-producing activity (ELISA) of dermal fibroblasts compared to classically (LPS) and alternatively (IL-4) activated macrophages. Macrophages polarized by the interaction with apoptotic cells had a unique phenotype and profile of produced factors and differed from the compared macrophage subtypes. Their conditioned media promoted the proliferation of dermal fibroblasts and the expression of α-SMA in them at the level of macrophages stimulated by IL-4, while the stimulating effect on the collagen-producing activity was more pronounced compared to that of the other macrophage subtypes. Moreover, they are characterized by the high level of production of pro-fibrotic factors such as TIMP-1, TGF-β1 and angiogenin. Taken together, M2-like macrophages polarized by efferocytosis demonstrate in vitro pro-fibrotic activity by promoting the functional activity of dermal fibroblasts and producing pro-fibrotic and pro-angiogenic factors.

Interleukin-19 Gene-Deficient Mice Promote Liver Fibrosis via Enhanced TGF-β Signaling, and the Interleukin-19-CCL2 Axis Is Important in the Direction of Liver Fibrosis

IL-19 is a cytokine discovered by homologous searching with IL-10 and is produced by non-immune cells, such as keratinocytes, in addition to immune cells, such as macrophages. Liver fibrosis results from the inflammation and activation of hepatic stellate cells via chronic liver injury. However, the participation of IL-19 in liver fibrosis remains to be sufficiently elucidated. Our group studied the immunological function of IL-19 in a mouse model of carbon tetrachloride (CCl₄)-induced liver fibrosis. IL-19 gene-deficient (KO) mice and body weight-matched wild-type (WT) mice were used. A liver fibrosis mouse model was created via CCl₄ administration (two times per week) for 8 weeks. In CCl₄-induced liver fibrosis, serum analysis revealed that IL-19 KO mice had higher ALT levels compared to WT mice. IL-19 KO mice had worse fibrosis, as assessed by morphological evaluation of total area stained positive with Azan and Masson trichrome. In addition, the expression of α-SMA was increased in liver tissues of IL-19 KO mice compared to WT mice. Furthermore, mRNA expression levels of TGF-β and α-SMA were enhanced in IL-19 KO mice compared to WT mice. In vitro assays revealed that IL-19-high expressing RAW264.7 cells inhibited the migration of NIH3T3 cells via the inhibited expression of CCL2 in the presence of CCl₄ and IL-4. These findings indicate that IL-19 plays a critical role in liver fibrosis by affecting TGF-β signaling and the migration of hepatic stellate cells during liver injury. Enhancement of the IL-19 signaling pathway is a potential treatment for liver fibrosis.

Elucidating shared biomarkers and pathways in kidney stones and diabetes: insights into novel therapeutic targets and the role of resveratrol

BACKGROUND

The pathogenic mechanisms shared between kidney stones and diabetes at the transcriptional level remain elusive, and the molecular mechanisms by which resveratrol exerts its protective effects against these conditions require further investigation.

METHODS

To address these gaps in knowledge, we conducted a comprehensive analysis of microarray and RNA-seq datasets to elucidate shared biomarkers and biological pathways involved in the pathogenesis of kidney stones and diabetes. An assortment of bioinformatic approaches was employed to illuminate the common molecular markers and associated pathways, thereby contributing to the identification of innovative therapeutic targets. Further investigation into the molecular mechanisms of resveratrol in preventing these conditions was conducted using molecular docking simulation and first-principles calculations.

RESULTS

The study identified 11 potential target genes associated with kidney stones and diabetes through the intersection of genes from weighted gene co-expression network analysis (WGCNA) and differentially expressed genes (DEGs) screening. Among these, Interleukin 11 (IL11) emerged as a pivotal hub gene and a potential diagnostic biomarker for both conditions, particularly in males. Expression analysis of IL11 demonstrated elevated levels in kidney stones and diabetes groups compared to controls. Additionally, IL11 exhibited correlations with specific cell types and differential expression in normal and pathological conditions. Gene set enrichment analysis (GSEA) highlighted significant disparities in biological processes, pathways, and immune signatures associated with IL11. Moreover, molecular docking simulation of resveratrol towards IL11 and a first-principles investigation of Ca adsorption on the resveratrol surface provided structural evidence for the development of resveratrol-based drugs for these conditions.

CONCLUSIONS

Overall, this investigation illuminates the discovery of common molecular mechanisms underlying kidney stones and diabetes, unveils potential diagnostic biomarkers, and elucidates the significance of IL11 in these conditions. It also provides insights into IL11 as a promising therapeutic target and highlights the role of resveratrol. Nonetheless, further research is warranted to enhance our understanding of IL11 targeting mechanisms and address any limitations in the study.