Animal Models Of Fibrosis Research Articles

Development of Mesenchymal Stem Cell Encoded with Myogenic Gene for Treating Radiation-Induced Muscle Fibrosis.

Radiation therapy (RT) is a typical treatment for head and neck cancers. However, prolonged irradiation of the esophagus can cause esophageal fibrosis due to increased reactive oxygen species and proinflammatory cytokines. The objective of this study was to determine whether myogenic gene-transfected mesenchymal stem cells (MSCs) could ameliorate damage to esophageal muscles in a mouse model of radiation-induced esophageal fibrosis. We cloned esophageal myogenic genes (MyoD, MyoG, and Myf6) using plasmid DNA. Afterward, myogenic genes were transfected into Human Mesenchymal Stem Cells (hMSCs) using electroporation. Gene transfer efficiency, stemness, and myogenic gene profile were examined using flow cytometry, quantitative polymerase chain reaction, and RNA sequencing. In vivo efficacy of gene-transfected hMSCs was demonstrated through histological and gene expression analyses using a radiation-induced esophageal fibrosis animal model. We have confirmed that the gene transfer efficiency was high (∼75%). Pluripotency levels in gene-transfected MSCs were significantly decreased compared with those in the control (vector). Particularly, myogenesis-related genes such as OAS2, OAS3, and HSPA1A were overexpressed in the group transfected with three genes. At 4 weeks after injection, it was found that thickness collagen layer and esophageal muscle in MSCs transfected with all three genes were significantly reduced compared to those in the saline group. Muscularis mucosa was observed prominently in the gene combination group. Moreover, expression levels of myogenin, Myf6, calponin, and SM22α known to be specific markers of esophageal muscles tended to increase in the group transfected with three genes. Therefore, using gene-transfected MSCs has the potential as a promising therapy against radiation-induced esophageal fibrosis.

Spatiotemporal delivery of multiple components of rhubarb-astragalus formula for the sysnergistic treatment of renal fibrosis.

Rhubarb (Rheum palmatum L.) and astragalus (Radix astragali) find widespread used in clinical formulations for treating chronic kidney disease (CKD). Notably, the key active components, total rhubarb anthraquinone (TRA) and total astragalus saponin (TAS), exhibit superiority over rhubarb and astragalus in terms of their clear composition, stability, quality control, small dosage, and efficacy for disease treatment. Additionally, astragalus polysaccharides (APS) significantly contribute to the treatment of renal fibrosis by modulating the gut microbiota. However, due to differences in the biopharmaceutical properties of these components, achieving synergistic effects remains challenging. This study aims to develop combined pellets (CPs) and evaluate the potential effect on unilateral ureteral obstruction (UUO)-induced renal fibrosis. The CPs pellets were obtained by combining TRA/TAS-loaded SNEDDS pellets and APS-loaded pellets, prepared using the fluidized bed coating process. The prepared pellets underwent evaluation for morphology, bulk density, hardness, and flowing property. Moreover, the in vitro release of the payloads was evaluated with the CHP Type I method. Furthermore, the unilateral ureteral obstruction (UUO) model was utilized to investigate the potential effects of CPs pellets on renal fibrosis and their contribution to gut microbiota modulation. The ex-vivo study demonstrated that the developed CPs pellets not only improved the dissolution of TRA and TAS but also delivered TRA/TAS and APS spatiotemporally to the appropriate site along the gastrointestinal tract. In an animal model of renal fibrosis (UUO rats), oral administration of the CPs ameliorated kidney histological pathology, reduced collagen deposition, and decreased the levels of inflammatory cytokines. The CPs also restored the disturbed gut microbiota induced by UUO surgery and protected the intestinal barrier. The developed CPs pellets represent a promising strategy for efficiently delivering active components in traditional Chinese medicine formulas, offering an effective approach for treating CKD.

Effects of Particulate Matter on CKD: Inflammation, Oxidative Stress, and Fibrosis in Animal Model

Effects of Particulate Matter on CKD: Inflammation, Oxidative Stress, and Fibrosis in Animal Model

Protective effect of hydroxysafflor yellow a on thioacetamide-induced liver injury and osteopenia in zebrafish

Hydroxysafflor yellow A (HSYA) is the main water-soluble compound of safflower. It is commonly used in liver disease treatment and has anti-osteoporotic activity. However, the specific mechanism of HSYA is not yet fully understood. Thioacetamide (TAA) has toxic effects on the liver and is widely used in establishing animal models of cirrhosis and liver fibrosis. In research of liver-related diseases and bone deformation in vivo, the zebrafish has become a frequently utilized animal model. In establishing a TAA-induced zebrafish liver injury model, we found that TAA-induced zebrafish also developed osteopenia. The aim of our study is to investigate the protective effect of HSYA on TAA-induced liver injury and osteopenia in zebrafish. The findings demonstrated that HSYA alleviated hepatic oxidative stress, inhibited the release of inflammatory factors, and promoted in vivo skeletal mineralization in zebrafish larvae. Further Real-time Polymerase Chain Reaction and Western blotting analyses showed that HSYA altered the expression levels of SIRT1, HMGB1, TLR4, MYD88 and NF-ΚB, ameliorated TAA-induced liver injury, reduced the release of inflammation-related factors IL-6, IL-1β, TNF-α, regulated the ratio of RANKL/OPG, ameliorated TAA-induced osteopenia. In conclusion, our study demonstrated that HSYA exhibited a noteworthy beneficial influence on TAA-induced liver injury and osteopenia in zebrafish, this finding provide a foundation for the application of HSYA in clinical research.

Mesenchymal stem cell therapy for liver fibrosis need "partner": Results based on a meta-analysis of preclinical studies.

The efficacy of mesenchymal stem cells (MSCs) in treating liver fibrosis has been demonstrated in several clinical studies. However, their low survival and liver implantation rates remain problematic. In recent years, a large number of studies in animal models of liver fibrosis have shown that MSCs combined with drugs can improve the efficacy of MSCs in the treatment of liver fibrosis alone and inhibit its progression to end-stage liver disease. This has inspired new ways of thinking about treating liver fibrosis. To investigate the effectiveness and mechanisms of MSCs combined with drugs in treating liver fibrosis. Data sources included four electronic databases and were constructed until January 2024. The subjects, interventions, comparators, outcomes, and study design principle were used to screen the literature, and the quality of the literature was evaluated to assess the risk of bias. Relevant randomised controlled trials were selected, and the final 13 studies were included in the final study. A total of 13 studies were included after screening. Pooled analysis showed that MSCs combined with drug therapy significantly improved liver function, promoted the repair of damaged liver tissues, reduced the level of liver fibrosis-related indexes, and effectively ameliorated hepatic fibrosis by modulating the hepatic inflammatory microenvironment, promoting the homing of MSCs, and regulating the relevant signaling pathways, and the treatment efficacy was superior to MSCs alone. However, the combined treatment statistics showed no ame-lioration in serum albumin levels (standardized mean difference = 0.77, 95% confidence interval: -0.13 to 1.68, P = 0.09). In conclusion, MSCs combined with drugs for treating liver fibrosis effectively make up for the shortcomings of MSCs in their therapeutic effects. However, due to the different drugs, the treatment mechanism and effect also differ. Therefore, more randomized controlled trials are needed to compare the therapeutic efficacy of different drugs in combination with MSCs, aiming to select the "best companion" of MSCs in treating hepatic fibrosis.

Iron-laden macrophage-mediated paracrine profibrotic signaling induces lung fibroblast activation.

Idiopathic pulmonary fibrosis (IPF) is a devastating condition characterized by progressive lung scarring and uncontrolled fibroblast proliferation, inevitably leading to organ dysfunction and mortality. Although elevated iron levels have been observed in patients and animal models of lung fibrosis, the mechanisms linking iron dysregulation to lung fibrosis pathogenesis, particularly the role of macrophages in orchestrating this process, remain poorly elucidated. Here we evaluate iron metabolism in macrophages during pulmonary fibrosis using both in vivo and in vitro approaches. In murine bleomycin- and amiodarone-induced pulmonary fibrosis models, we observed significant iron deposition and lipid peroxidation in pulmonary macrophages. Intriguingly, the ferroptosis regulator glutathione peroxidase 4 (GPX4) was upregulated in pulmonary macrophages following bleomycin instillation, a finding corroborated by single-cell RNA sequencing analysis. Moreover, macrophages isolated from fibrotic mouse lungs exhibited increased transforming growth factor (TGF)-β1 expression that correlated with lipid peroxidation. In vitro, iron overload in bone marrow-derived macrophages triggered lipid peroxidation and TGF-β1 upregulation, which was effectively suppressed by ferroptosis inhibitors. When cocultured with iron-overloaded macrophages, lung fibroblasts exhibited heightened activation, evidenced by increased α-smooth muscle actin and fibronectin expression. Importantly, this profibrotic effect was attenuated by treating macrophages with a ferroptosis inhibitor or blocking TGF-β receptor signaling in fibroblasts. Collectively, our study elucidates a novel mechanistic paradigm in which the accumulation of iron within macrophages initiates lipid peroxidation, thereby amplifying TGF-β1 production, subsequently instigating fibroblast activation through paracrine signaling. Thus, inhibiting iron overload and lipid peroxidation warrants further exploration as a strategy to suppress fibrotic stimulation by disease-associated macrophages. NEW & NOTEWORTHY This study investigates the role of iron in pulmonary fibrosis, specifically focusing on macrophage-mediated mechanisms. Iron accumulation in fibrotic lung macrophages triggers lipid peroxidation and an upregulation of transforming growth factor (TGF)-β1 expression. Coculturing iron-laden macrophages activates lung fibroblasts in a TGF-β1-dependent manner, which can be mitigated by ferroptosis inhibitors. These findings underscore the potential of targeting iron overload and lipid peroxidation as a promising strategy to alleviate fibrotic stimulation provoked by disease-associated macrophages.

Engineered lipid nanoparticles enable therapeutic gene silencing of GTSE1 for the treatment of liver fibrosis

Liver fibrosis is characterized by abnormal accumulation of extracellular matrix proteins, disrupting normal liver function. Despite its significant health impact, effective treatments remain limited. Here, we present the development of engineered lipid nanoparticles (LNPs) for targeted RNA therapeutic delivery in the liver. We investigated the therapeutic potential of modulating the G2 and S-phase expressed 1 (GTSE1) protein for treating liver fibrosis. Through screening, we identified P138Y LNP as a potent candidate with superior delivery efficiency and lower toxicity. Using these engineered LNPs, we successfully delivered siGTSE1 to hepatocytes, significantly reducing collagen accumulation and restoring liver function in a fibrosis animal model. Additionally, GTSE1 downregulation altered miRNA expression and upregulated hepatocyte nuclear factor 4 alpha (HNF4α). These findings suggest that therapeutic gene silencing of GTSE1 is a promising strategy for treating liver fibrosis by regenerating liver phenotypes and functions.

Particulate Matter induces Renal Inflammation, Oxidative Stress and Fibrosis in Animal Model of Chronic Kidney Disease (CKD)

Particulate Matter induces Renal Inflammation, Oxidative Stress and Fibrosis in Animal Model of Chronic Kidney Disease (CKD)

Nuclear receptor 4A1 ameliorates renal fibrosis by inhibiting vascular endothelial growth factor A induced angiogenesis in UUO rats

IntroductionAngiogenesis is closely related to renal fibrosis; however, its basic mechanism remains unclear. In our study, we found that nuclear receptor 4A1 (NR4A1) inhibits vascular endothelial growth factor A (VEGFA)-induced angiogenesis, ameliorating renal fibrosis. MethodsWe prepared a renal fibrosis animal model with unilateral ureteral obstruction (UUO) and NR4A1 knockdown UUO mice model, Using Human umbilical vein endothelial cells (HUVECs) to conduct all in vitro experiments. We then detected and analyzed the expression levels of NR4A1 and other genes related to angiogenesis and fibrosis. ResultsThe angiogenesis related genes, such as VEGFA, vascular endothelial growth factor receptor-2 (VEGFR-2), endoglin (CD105), as well as the expression of fibrosis related genes that included, α-smooth muscle actin (α-SMA), Vimentin, and Collagen I are all significantly increased in the UUO rat model. In addition, the expression of NR4A1 of the kidney tissue of UUO rats was significantly reduced. Therefore, according to the above results, we speculated that angiogenesis may exacerbate renal fibrosis and NR4A1 may repress renal fibrosis by inhibiting angiogenesis. To further verify the above results, we used VEGFA to stimulate HUVECs with (or without) overexpression or knockdown of NR4A1. The results showed that with prolonged stimulation using VEGFA, the expression of NR4A1 decreases. Overexpression of NR4A1 significantly inhibits the expression of related indicators of angiogenesis and renal fibrosis. Furthermore, knockdown of NR4A1 induces endothelial cell proliferation and migration; therefore, exacerbating angiogenesis and fibrosis. Finally, the results of NR4A1 knockdown UUO mice showed that knockdown of NR4A1 can aggravating kidney damage and induce the expression of angiogenesis and renal fibrosis related indicators, while UUO can significantly induce kidney damage, angiogenesis and renal fibrosis. When knockdown of NR4A1, renal kidney damage, angiogenesis and fibrosis becomes more severe than UUO. Thus, all of these results indicate that NR4A1 can ameliorate renal fibrosis by inhibiting angiogenesis. ConclusionsNR4A1 can inhibit angiogenesis to ameliorate renal fibrosis.

Piezo ion channels: long-sought-after mechanosensors mediating hypertension and hypertensive nephropathy.

Recent advances in mechanobiology and the discovery of mechanosensitive ion channels have opened a new era of research on hypertension and related diseases. Piezo1 and Piezo2, first reported in 2010, are regarded as bona fide mechanochannels that mediate various biological and pathophysiological phenomena in multiple tissues and organs. For example, Piezo channels have pivotal roles in blood pressure control, triggering shear stress-induced nitric oxide synthesis and vasodilation, regulating baroreflex in the carotid sinus and aorta, and releasing renin from renal juxtaglomerular cells. Herein, we provide an overview of recent literature on the roles of Piezo channels in the pathogenesis of hypertension and related kidney damage, including our experimental data on the involvement of Piezo1 in podocyte injury and that of Piezo2 in renin expression and renal fibrosis in animal models of hypertensive nephropathy. The mechanosensitive ion channels Piezo1 and Piezo2 play various roles in the pathogenesis of systemic hypertension by acting on vascular endothelial cells, baroreceptors in the carotid artery and aorta, and the juxtaglomerular apparatus. Piezo channels also contribute to hypertensive nephropathy by acting on mesangial cells, podocytes, and perivascular mesenchymal cells.

Noninvasive assessment of liver fibrosis in mini pigs using an 18F–AlF-NOTA-RGD2 PET/CT molecular probe

To evaluate the efficacy of the 18F–AlF-NOTA-RGD2 positron emission tomography (PET)/computed tomography (CT) molecular probe for the noninvasive staging of liver fibrosis in mini pigs, a potential alternative to invasive diagnostic methods was revealed. This study used 18F–AlF-NOTA-RGD2 PET/CT imaging of mini pigs to assess liver fibrosis. The methods included synthesis and quality control of the molecular probe, establishment of an animal model of liver fibrosis, blood serum enzymatic tests, histopathological examination, PET/CT imaging, collagen content and expression, and mitochondrial reserve function assessment. The 18F–AlF-NOTA-RGD2 PET/CT molecular probe effectively differentiated various stages of liver fibrosis in mini pigs. Blood serum enzymatic tests revealed distinct stages of liver fibrosis, revealing significant increases in AST, ALT, TBIL, and DBIL levels as fibrosis advanced. Notably, ALT levels increased markedly in severe fibrosis patients. A gradual increase in collagen deposition and increasing α-SMA RNA expression and protein levels effectively differentiated between mild and severe fibrosis stages. Pathological examinations and Sirius Red staining confirmed these findings, highlighting substantial increases in collagen accumulation. PET/CT imaging results aligned with histopathological findings, showing that increased radiotracer uptake correlated with fibrosis severity. Assessments of mitochondrial function revealed a decrease in total liver glutathione content and mitochondrial reserve capacity, especially in patients with severe fibrosis. The 18F–AlF-NOTA-RGD2 PET/CT molecular probe is a promising tool for the noninvasive assessment of liver fibrosis, offering potential benefits over traditional diagnostic methods in hepatology.

Effectiveness and mechanisms of mesenchymal stem cell therapy in preclinical animal models of hepatic fibrosis: a systematic review and meta-analysis.

Liver damage due to long-term viral infection, alcohol consumption, autoimmune decline, and other factors could lead to the gradual development of liver fibrosis. Unfortunately, until now, there has been no effective treatment for liver fibrosis. Mesenchymal stem cells, as a promising new therapy for liver fibrosis, can slow the progression of fibrosis by migrating to the site of liver injury and by altering the microenvironment of the fibrotic area. By including all relevant studies to date to comprehensively assess the efficacy of mesenchymal stem cells for the treatment of hepatic fibrosis and to explore considerations for clinical translation and therapeutic mechanisms. Data sources included PubMed, Web of Science, Embase, and Cochrane Library, and were constructed until October 2023. Data for each study outcome indicator were extracted for comprehensive analysis. The overall meta-analysis showed that mesenchymal stem cells significantly improved liver function. Moreover, it inhibited the expression level of transforming growth factor-β [SMD = 4.21, 95% CI (3.02,5.40)], which in turn silenced hepatic stellate cells and significantly reduced the area of liver fibrosis [SMD = 3.61, 95% CI (1.41,5.81)]. Several outcome indicators suggest that mesenchymal stem cells therapy is relatively reliable in the treatment of liver fibrosis. The therapeutic effect is cell dose-dependent over a range of doses, but not more effective at higher doses. Bone-marrow derived mesenchymal stem cells were more effective in treating liver fibrosis than mesenchymal stem cells from other sources. Identifier CRD42022354768.

SFN promotes renal fibrosis via binding with MYH9 in chronic kidney disease

Chronic kidney disease (CKD) is a clinical syndrome characterized by persistent renal function decline. Renal fibrosis is the main pathological process in CKD, but an effective treatment does not exist. Stratifin (SFN) is a highly-conserved, multi-function soluble acidic protein. Therefore, this study explored the effects of SFN on renal fibrosis. First, we found that SFN was highly expressed in patients with CKD, as well as in renal fibrosis animal and cell models. Next, transforming growth factor-beta 1 (TGF-β1) induced injury and fibrosis in human renal tubule epithelial cells, and SFN knockdown reversed these effects. Furthermore, SFN knockdown mitigated unilateral ureteral obstruction (UUO)-induced renal tubular dilatation and renal interstitial fibrosis in mice. Liquid chromatography-tandem mass spectrometry/mass spectrometry (LC-MS/MS), co-immunoprecipitation (Co-IP), and immunofluorescence co-localization assays demonstrated that SFN bound the non-muscle myosin-encoding gene, myosin heavy chain 9 (MYH9), in the cytoplasm of renal tubular epithelial cells. MYH9 knockdown also reduced Col-1 and α-SMA expression, which are fibrosis markers. Finally, silencing SFN decreased MYH9 expression, alleviating renal fibrosis. These results suggest that SFN promotes renal fibrosis in CKD by interacting with MYH9. This study may provide potential strategies for the treatment of CKD.

Boiling histotripsy exhibits anti-fibrotic effects in animal models of liver fibrosis

Liver fibrosis is a hallmark of chronic liver disease which could lead to liver cirrhosis or liver cancer. However, there is currently lack of a direct treatment for liver fibrosis. Boiling histotripsy (BH) is an emerging non-invasive high-intensity focused ultrasound technique that can be employed to mechanically destruct solid tumour at the focus via acoustic cavitation without significant adverse effect on surrounding tissue. Here, we investigated whether BH can mechanically fractionate liver fibrotic tissue thereby exhibiting an anti-fibrotic effect in an animal model of liver fibrosis. BH-treated penumbra and its identical lobe showed reduced liver fibrosis, accompanied by increased hepatocyte specific marker expression, compared to the BH-untreated lobe. Furthermore, BH treatment improved serological liver function markers without notable adverse effects. The ability of BH to reduce fibrosis and promote liver regeneration in liver fibrotic tissue suggests that BH could potentially be an effective and reliable therapeutic approach against liver fibrosis.

Adult cardiomyocytes‐derived EVs for the treatment of cardiac fibrosis

AbstractCardiac fibrosis is a common pathological feature of cardiovascular diseases that arises from the hyperactivation of fibroblasts and excessive extracellular matrix (ECM) deposition, leading to impaired cardiac function and potentially heart failure or arrhythmia. Extracellular vesicles (EVs) released by cardiomyocytes (CMs) regulate various physiological functions essential for myocardial homeostasis, which are disrupted in cardiac disease. Therefore, healthy CM‐derived EVs represent a promising cell‐free therapy for the treatment of cardiac fibrosis.To this end, we optimized the culture conditions of human adult CMs to obtain a large yield of EVs without compromising cellular integrity by using a defined combination of small molecules. EVs were isolated by ultracentrifugation, and their characteristics were analysed. Finally, their effect on fibrosis was tested.Treatment of TGFβ‐activated human cardiac fibroblasts with EVs derived from CMs using our culture system resulted in a decrease in fibroblast activation markers and ECM accumulation. The rescued phenotype was associated with specific EV cargo, including multiple myocyte‐specific and antifibrotic microRNAs, although their effect individually was not as effective as the EV treatment. Notably, pathway analysis showed that EV treatment reverted the transcription of activated fibroblasts and decreased several signalling pathways, including MAPK, mTOR, JAK/STAT, TGFβ, and PI3K/Akt, all of which are involved in fibrosis development. Intracardiac injection of CM‐derived EVs in an animal model of cardiac fibrosis reduced fibrotic area and increased angiogenesis, which correlated with improved cardiac function.These findings suggest that EVs derived from human adult CMs may offer a targeted and effective treatment for cardiac fibrosis, owing to their antifibrotic properties and the specificity of cargo.

Metabolic MRI With Hyperpolarized 13 C-Pyruvate for Early Detection of Fibrogenic Kidney Metabolism.

Fibrosis is the final common pathway for chronic kidney disease and the best predictor for disease progression. Besides invasive biopsies, biomarkers for its detection are lacking. To address this, we used hyperpolarized 13 C-pyruvate MRI to detect the metabolic changes associated with fibrogenic activity of myofibroblasts. Hyperpolarized 13 C-pyruvate MRI was performed in 2 pig models of kidney fibrosis (unilateral ureteral obstruction and ischemia-reperfusion injury). The imaging data were correlated with histology, biochemical, and genetic measures of metabolism and fibrosis. The porcine experiments were supplemented with cell-line experiments to inform the origins of metabolic changes in fibrogenesis. Lastly, healthy and fibrotic human kidneys were analyzed for the metabolic alterations accessible with hyperpolarized 13 C-pyruvate MRI. In the 2 large animal models of kidney fibrosis, metabolic imaging revealed alterations in amino acid metabolism and glycolysis. Conversion from hyperpolarized 13 C-pyruvate to 13 C-alanine decreased, whereas conversion to 13 C-lactate increased. These changes were shown to reflect profibrotic activity in cultured epithelial cells, macrophages, and fibroblasts, which are important precursors of myofibroblasts. Importantly, metabolic MRI using hyperpolarized 13 C-pyruvate was able to detect these changes earlier than fibrosis-sensitive structural imaging. Lastly, we found that the same metabolic profile is present in fibrotic tissue from human kidneys. This affirms the translational potential of metabolic MRI as an early indicator of fibrogenesis associated metabolism. Our findings demonstrate the promise of hyperpolarized 13 C-pyruvate MRI for noninvasive detection of fibrosis development, which could enable earlier diagnosis and intervention for patients at risk of kidney fibrosis.

Regulation of the RhoA exchange factor GEF-H1 by profibrotic stimuli through a positive feedback loop involving RhoA, MRTF, and Sp1.

RhoA and its effectors, the transcriptional coactivators myocardin-related transcription factor (MRTF) and serum response factor (SRF), control epithelial phenotype and are indispensable for profibrotic epithelial reprogramming during fibrogenesis. Context-dependent control of RhoA and fibrosis-associated changes in its regulators, however, remain incompletely characterized. We previously identified the guanine nucleotide exchange factor GEF-H1 as a central mediator of RhoA activation in renal tubular cells exposed to inflammatory or fibrotic stimuli. Here we found that GEF-H1 expression and phosphorylation were strongly elevated in two animal models of fibrosis. In the Unilateral Ureteral Obstruction mouse kidney fibrosis model, GEF-H1 was upregulated predominantly in the tubular compartment. GEF-H1 was also elevated and phosphorylated in a rat pulmonary artery banding (PAB) model of right ventricular fibrosis. Prolonged stimulation of LLC-PK1 tubular cells with tumor necrosis factor (TNF)-α or transforming growth factor (TGF)-β1 increased GEF-H1 expression and activated a luciferase-coupled GEF-H1 promoter. Knockdown and overexpression studies revealed that these effects were mediated by RhoA, cytoskeleton remodeling, and MRTF, indicative of a positive feedback cycle. Indeed, silencing endogenous GEF-H1 attenuated activation of the GEF-H1 promoter. Of importance, inhibition of MRTF using CCG-1423 prevented GEF-H1 upregulation in both animal models. MRTF-dependent increase in GEF-H1 was prevented by inhibition of the transcription factor Sp1, and mutating putative Sp1 binding sites in the GEF-H1 promoter eliminated its MRTF-dependent activation. As the GEF-H1/RhoA axis is key for fibrogenesis, this novel MRTF/Sp1-dependent regulation of GEF-H1 abundance represents a potential target for reducing renal and cardiac fibrosis.NEW & NOTEWORTHY We show that expression of the RhoA regulator GEF-H1 is upregulated in tubular cells exposed to fibrogenic cytokines and in animal models of kidney and heart fibrosis. We identify a pathway wherein GEF-H1/RhoA-dependent MRTF activation through its noncanonical partner Sp1 upregulates GEF-H1. Our data reveal the existence of a positive feedback cycle that enhances Rho signaling through control of both GEF-H1 activation and expression. This feedback loop may play an important role in organ fibrosis.

Oxidative modification of miR-30c promotes cardiac fibroblast proliferation via CDKN2C mismatch

The response of cardiac fibroblast proliferation to detrimental stimuli is one of the main pathological factors causing heart remodeling. Reactive oxygen species (ROS) mediate the proliferation of cardiac fibroblasts. However, the exact molecular mechanism remains unclear. In vivo, we examined the oxidative modification of miRNAs with miRNA immunoprecipitation with O8G in animal models of cardiac fibrosis induced by Ang II injection or ischemia‒reperfusion injury. Furthermore, in vitro, we constructed oxidation-modified miR-30c and investigated its effects on the proliferation of cardiac fibroblasts. Additionally, luciferase reporter assays were used to identify the target of oxidized miR-30c. We found that miR-30c oxidation was modified by Ang II and PDGF treatment and mediated by excess ROS. We demonstrated that oxidative modification of G to O8G occurred at positions 4 and 5 of the 5′ end of miR-30c (4,5-oxo-miR-30c), and this modification promoted cardiac fibroblast proliferation. Furthermore, CDKN2C is a negative regulator of cardiac fibroblast proliferation. 4,5-oxo-miR-30c misrecognizes CDKN2C mRNA, resulting in a reduction in protein expression. Oxidized miR-30c promotes cardiac fibroblast proliferation by mismatch mRNA of CDKN2C.

Therapeutic effects of flavonoids on pulmonary fibrosis: A preclinical meta-analysis

BackgroundThe efficacy of flavonoid supplementation in animal models of pulmonary fibrosis has been demonstrated. PurposeWe conducted a systematic review and meta-analysis to evaluate the efficacy and underlying mechanisms of flavonoids in animal models of bleomycin-induced pulmonary fibrosis. Study designRelevant studies (n = 45) were identified from English- and Chinese-language databases from the inception of the database until October 2023. MethodsMethodological quality was evaluated using the SYRCLE risk of bias tool. Statistical analyses were conducted using RevMan 5.3 and Stata 17.0. Lung inflammation and fibrosis score were the primary outcome indicators. ResultsFlavonoids can alleviate pathological changes in the lungs. The beneficial effects of flavonoids on pulmonary fibrosis likely relate to their inhibition of inflammatory responses, restoration of oxidative and antioxidant homeostasis, and regulation of fibroblast proliferation, migration, and activation by transforming growth factor β1/mothers against the decapentaplegic homologue/AMP-activated protein kinase (TGF-β1/Smad3/AMPK), inhibitor kappa B alpha/nuclear factor-kappa B (IκBα/NF-κB), phosphatidylinositol 3-kinase (PI3K)/AKT, interleukin 6/signal transducer/activator of transcription 3 (IL6/STAT3), and nuclear factor erythroid 2-related factor 2/Kelch-like ECH-associated protein 1 (Nrf2-Keap1) pathways. ConclusionFlavonoids are potential candidate compounds for the prevention and treatment of pulmonary fibrosis. However, extensive preclinical research is necessary to confirm the antifibrotic properties of natural flavonoids.

The curative effect of ethanolic extract of Moringa oleifera leaf in an animal model of liver fibrosis

Studies about the prevention effect of Moringa oleifera on liver fibrosis has been reported. However, its curative effect has not been reported, yet. This study was conducted to evaluate the curative effect of M. oleifera leaf extract on liver fibrosis. It was a laboratory experimental study with a post-test-only control group design. Rats were divided into 5 groups i.e. normal control which received intraperitoneally injections of 1 mL/kg BW of 0.9% NaCl solution twice a wk for 11 wk. Liver fibrosis control which received intraperitoneally injections of 1 mL/kg BW of 10% CCl4 solution twice a wk for 11 wk. Three M. oleifera treatment group which received intraperitoneally injections of 1 mL/kg BW of 10% CCl4 solution twice a wk for 11 wk continued by M. oleifera leaf ethanolic extract at dose of 600 mg/kg BW daily for 3 (MO3), 6 (MO6), and 10 (MO10) wk, respectively. The liver fibrosis level was assessed based on the METAVIR score. Histopathological analysis of liver tissues demonstrated that the 11-week CCl4 induction successfully resulted in liver fibrosis in rats (F3 and F4). The administration of M. oleifera leaf ethanolic extract decreased METAVIR scores ranged from F3 to F1. The optimal reduction of the METAVIR scores (F1) was observed in MO3 group after 6 wk administration (p<0.05). It was indicated that M. oleifera leaf ethanolic extract ameliorated liver fibrosis. In conclusion, M. oleifera leaf ethanolic extract has a curative effect against liver fibrosis.