TGF-β orchestrates fibrogenic and developmental EMTs via the RAS effector RREB1

Carthamin yellow-loaded glycyrrhetinic acid liposomes alleviate interstitial fibrosis in diabetic nephropathy

OBJECTIVES

To investigate the therapeutic efficacy of Carthamin yellow (CY)-loaded glycyrrhetinic acid (GA) liposomes in treating diabetic nephropathy (DN), particularly in alleviating renal interstitial fibrosis and improving kidney function.

METHODS

CY-loaded GA liposomes were prepared and characterized for structural stability and controlled release. DN rat models were treated with CY-loaded GA liposomes, and kidney pathology, function, collagen deposition, and TGF-β1 expression were evaluated. The effects of CY-loaded GA liposomes were compared to Vitamin E and CY alone. In vitro experiments with TGF-β1-stimulated human renal interstitial fibroblasts (hRIFs) examined the effects of CY-loaded GA liposomes on cell proliferation and the expression of fibrotic markers. Mechanistic studies assessed the role of the TGFBR1/Smad2/Smad3 pathway using TGFBR1 overexpression experiments.

RESULTS

The CY-loaded GA liposomes exhibited a stable structure and controlled release profile. In DN rats, treatment with CY-loaded GA liposomes significantly alleviated kidney damage, improved kidney function, reduced collagen deposition and fibrosis, and downregulated TGF-β1 expression, showing superior effects compared to Vitamin E or CY alone. In TGF-β1-stimulated hRIFs, CY-loaded GA liposomes effectively suppressed cell proliferation and reduced the expression of Cyclin D1, PCNA, fibronectin, and collagen I. The inhibitory effects were stronger than CY alone and were mediated by the inactivation of the TGFBR1/Smad2/Smad3 pathway, as confirmed by TGFBR1 overexpression studies.

CONCLUSIONS

CY-loaded GA liposomes demonstrated significant therapeutic efficacy in alleviating renal interstitial fibrosis in DN by targeting the TGFBR1/Smad2/Smad3 pathway. This novel drug delivery system provides a promising approach for the treatment of DN.

Reticulophagy promotes EMT-induced fibrosis in offspring's lung tissue after maternal exposure to carbon black nanoparticles during gestation by a m5C-dependent manner

Accumulating evidence indicates that maternal exposure to carbon black nanoparticles (CBNPs) during gestation can induce multiple system abnormalities in offspring, whereas its potential mechanism in respiratory disease is still largely unknown. In order to explore the effect of maternal exposure to CBNPs on offspring's lung and latent pathogenesis, we respectively established in vivo model of pregnant rats exposed to CBNPs and ex vivo model of lung epithelial cells treated with pups' serum of pregnant rats exposed to CBNPs. After maternal exposure to CBNPs, epithelial-mesenchymal transition (EMT) and fibrosis levels increased as a result of DDRGK1-mediated reticulophagy upregulated in offspring's lung. DDRGK1 as FAM134B's cargo bound with FAM134B to mediate reticulophagy. Transcription factor "SP1" positively regulated DDRGK1 gene expression by binding to its promoter. Furthermore, the upregulation of NSUN2 elevated m5C methylation of SP1 mRNA and the protein level of SP1 subsequently increased through Ybx1 recognizing and stabilizing m5C-methylated SP1 mRNA, followed by the increased levels of reticulophagy and fibrosis in lung epithelial cells treated with offspring's serum of matrix exposed to CBNPs during gestation. In conclusion, NSUN2/Ybx1/m5C-SP1 axis promoted DDRGK1-mediated reticulophagy, which played an important role in EMT-induced fibrosis in offspring's lung tissue after maternal exposure to CBNPs during gestation.

The SUMOylated RREB1 interacts with KDM1A to induce 5-fluorouracil resistance via upregulating thymidylate synthase and activating DNA damage response pathway in colorectal cancer

Chemoresistance is one main cause of failure in colorectal cancer (CRC) treatment. The role of transcription factor Ras-responsive element binding protein 1 (RREB1) remains unclarified in CRC chemoresistance. Herein, we reveal that RREB1 functions as an oncogene to promote cell proliferation and 5-fluorouracil (5-FU) chemoresistance in CRC, and SUMOylation is required for RREB1 to exert its oncogenic role in CRC. RREB1 induced cell cycle arrest at the S-phase and a decreased apoptosis rate under 5-FU exposure. Mechanistically, the interaction of RREB1 with lysine demethylase 1A (KDM1A) elevated expression of 5-FU targeting proteins thymidylate synthase (TS) and thymidine kinase (TK1) to maintain the nucleotide pool balance under 5-FU treatment, and enhanced activation of Chk1-mediated DNA damage response (DDR) pathway. The deSUMOylation of RREB1 resulted in a reduced interaction of RREB1 with KDM1A, contributing to a downregulation of TS expression and a less activation of DDR pathway. Moreover, KDM1A knockdown improved the DNA damage and reduced RREB1-mediated resistance to 5-FU. These findings provide new insights into RREB1-mediated chemotherapy responses in CRC and indicate RREB1 is a potential target for overcoming 5-FU resistance.

Complex regulation of cardiac fibrosis: insights from immune cells and signaling pathways

Cardiac fibrosis is a physiological process that involves the formation of scar tissue in the heart in response to injury or damage. This process is initially a protective measure characterized by enhanced fibroblasts, which are responsible for producing extracellular matrix proteins that provide structural support to the heart. However, when fibrosis becomes excessive, it can lead to adverse outcomes, including increasing tissue stiffness and impaired cardiac function, which can ultimately result in heart failure with a poor prognosis. While fibroblasts are the primary cells involved in cardiac fibrosis, immune cells have also been found to play a vital role in its progression. Recent research has shown that immune cells exert multifaceted effects besides regulation of inflammatory response. Advanced research techniques such as single-cell sequencing and multiomics have provided insights into the specific subsets of immune cells involved in fibrosis and the complex regulation of the process. Targeted immunotherapy against fibrosis is gaining traction as a potential treatment option, but it is still unclear how immune cells achieve this regulation and whether distinct subsets are involved in different roles. To better understand the role of immune cells in cardiac fibrosis, it is essential to examine the classical signaling pathways that are closely related to fibrosis formation. We have also focused on the unique properties of diverse immune cells in cardiac fibrosis and their specific intercommunications. Therefore, this review will delve into the plasticity and heterogeneity of immune cells and their specific roles in cardiac fibrosis, which propose insights to facilitate the development of anti-fibrosis therapeutic strategies.

ERBB4 selectively amplifies TGF-β pro-metastatic responses

Transforming growth factor β (TGF-β) is well known to play paradoxical roles in tumorigenesis as it has both growth-inhibitory and pro-metastatic effects. However, the underlying mechanisms of how TGF-β drives the opposing responses remain largely unknown. Here, we report that ERBB4, a member of the ERBB receptor tyrosine kinase family, specifically promotes TGF-β's metastatic response but not its anti-growth response. ERBB4 directly phosphorylates Tyr162 in the linker region of SMAD4, which enables SMAD4 to achieve a higher DNA-binding ability and potentiates TGF-β-induced gene transcription associated with epithelial-to-mesenchymal transition (EMT), cell migration, and invasion without affecting the genes involved in growth inhibition. These selective effects facilitate lung cancer metastasis in mouse models. This discovery sheds light on the previously unrecognized role of SMAD4 as a substrate of ERBB4 and highlights the selective involvement of the ERBB4-SMAD4 regulatory axis in tumor metastasis.

Adaptation to acidic conditions that mimic the tumor microenvironment, downregulates miR-193b-3p, and induces EMT via TGFβ2 in A549 cells

The acidic tumor microenvironment plays a critical role in the malignant transformation of cancer cells. One mechanism underlying this transformation involves epithelial-mesenchymal transition (EMT). This is induced by prolonged exposure to acidic conditions. EMT is an essential process in cancer progression, with Transforming Growth Factor Beta (TGF-β) playing a central role in its induction. However, little was known about the factors regulating TGF-β under acidic conditions. This study aimed to elucidate the mechanism of EMT under acidic conditions and identify novel therapeutic targets to inhibit cancer cell migration and metastasis. Focusing on lung cancer, we explored microRNAs associated with EMT that were differentially expressed under acidic conditions in A549 cells and identified miR-193b-3p as a novel candidate. Under acidic conditions, miR-193b-3p expression decreased around days 3-14. Downregulation of miR-193b-3p promoted increased TGFβ2 expression, resulting in EMT changes in A549 cells. Our study suggests that the interaction between miR-193b-3p, TGFβ2, and the acidic tumor microenvironment promotes cancer EMT change. Understanding these interactions may not only enhance our biological comprehension of cancer, but also pave the way for the development of targeted therapies to inhibit cancer metastasis.

Nuciferine Restores Autophagy via the PI3K-AKT-mTOR Pathway to Alleviate Renal Fibrosis in Diabetic Kidney Disease

Diabetic kidney disease (DKD) is one of the complications of diabetes mellitus, which triggers kidney fibrosis and eventually develops into end-stage renal disease. Nuciferine (NF) is one of the most important functional components in lotus leaves (LL), but its role and mechanism for the treatment of DKD are unclear. A high-fat-diet (HFD)-induced DKD model in KK-AY mice was established in this study. NF treatment significantly improved blood glucose and blood biochemical indices in DKD mice. Furthermore, NF reduced the levels of mALB, UCRE, Scr, and BUN in mice urine. Further, the extent of renal lesions in the mice in this study was at stage IV according to the Mogensen staging method. NF treatment was effective in ameliorating renal injury during this period. Concurrently, the protein levels of FN, N-cadherin, TGFβ, p-Smad3, p-PI3K, p-AKT, p-mTOR, and p62 were decreased. In contrast, the level of expression of Beclin-1 was increased. In the high glucose-exposed HK-2 cell model, the expression of p-PI3K, p-AKT, and p-mTOR was all downregulated, and autophagy proteins were increased after NF intervention. In addition, HK-2 cells were treated with high glucose in combination with Wortmannin and 3-MA, respectively. The results demonstrated that NF inhibited the expression of TGFβ and p-Smad3 by regulating autophagy through the PI3K-AKT-mTOR pathway, thereby ameliorating renal fibrosis at stage IV in mice. Therefore, LL can be used as a dietary component for the prevention of renal fibrosis in DKD patients.

The critical role of the Hippo signaling pathway in renal fibrosis

Renal fibrosis is a fundamental pathological change in the progression of various chronic kidney diseases to the end stage of renal disease. The Hippo signaling pathway is an evolutionary highly conserved signaling pathway that is involved in the regulation of organ size, tissue regeneration, and human reproduction and development. Currently, many studies have shown that it is closely associated with renal diseases, such as, renal fibrosis, diabetic nephropathy, and renal cancer. Here, we review the current researches on the effect of Hippo signaling pathway on renal fibrosis, which provides new ideas and theoretical basis for clinical therapeutics of renal fibrosis.

Phosphorylation of FOXN3 by NEK6 promotes pulmonary fibrosis through Smad signaling

The transcriptional repressor FOXN3 plays a key role in regulating pulmonary inflammatory responses, which are crucial in the development of pulmonary fibrosis. However, its specific regulatory function in lung fibrosis remains unclear. Here, we show that FOXN3 suppresses pulmonary fibrosis by inhibiting Smad transcriptional activity. FOXN3 targets a substantial number of Smad response gene promoters, facilitating Smad4 ubiquitination, which disrupts the association of the Smad2/3/4 complex with chromatin and abolishes its transcriptional response. In response to pro-fibrotic stimuli, NEK6 phosphorylates FOXN3 at S412 and S416, leading to its degradation. The loss of FOXN3 inhibits β-TrCP-mediated ubiquitination of Smad4, stabilizing the Smad complex's association with its responsive elements and promoting transcriptional activation, thus contributing to the development of pulmonary fibrosis. Notably, we found a significant inverse expression pattern between FOXN3 and Smad4 in clinical pulmonary fibrosis cases, underscoring the importance of the NEK6-FOXN3-Smad axis in the pathological process of pulmonary fibrosis.

FOXC1 promotes EMT and colorectal cancer progression by attracting M2 macrophages via the TGF-β/Smad2/3/snail pathway

Colorectal cancer is a highly prevalent and deadly malignancy worldwide. Current treatment strategies, including surgery, chemotherapy, and targeted therapy, still face limitations due to recurrence and metastasis. By conducting a weighted gene coexpression network analysis on gene expression data from The Cancer Genome Atlas, we pinpointed critical genes linked to M2 macrophages and tumor metastasis. Among these, FOXC1 emerged as a significant prognostic indicator within our predictive model. Clinical sample analysis further confirmed that FOXC1 is upregulated in colorectal cancer tissues and associated with an unfavorable patient outcome. Both in vivo and in vitro experimental results revealed that FOXC1 promotes CRC cell migration, invasion and proliferation by regulating the expression of Snail and TGF-β/Smad2/3 pathways, thereby facilitating the epithelial-mesenchymal transition process. Additionally, FOXC1 recruits M2 macrophages to the tumor microenvironment by regulating CXCL2 expression through Snail. The TGF-β factor secreted by M2 macrophages further activates the TGF-β/Smad2/3 pathway, forming a positive feedback loop. In these processes, FOXC1 plays a critical regulatory role. In summary, this study highlights the critical significance of FOXC1 in CRC progression and indicates its viability as a therapeutic target, offering a novel theoretical foundation for the development of future CRC treatment strategies.

Selective inhibition of TGF-β-induced epithelial-mesenchymal transition overcomes chemotherapy resistance in high-risk lung squamous cell carcinoma

Lung squamous cell carcinoma (LUSC) represents a major subtype of lung cancer, and it demonstrates limited treatment options and worse survival. Identifications of a prognostic model and chemoresistance mechanism can be helpful for improving stratification and guiding therapy decisions. The integrative development of machine learning-based models reveals a random survival forest (RSF) prognostic model for LUSC. The 12-gene RSF model exhibits high prognostic power in more than 1,000 LUSC patients. High-risk LUSC patients are associated with worse survival and the activation of the epithelial-mesenchymal transition pathway. Additionally, high-risk LUSC patients are resistant to docetaxel or vinorelbine treatment. In vitro and in vivo drug sensitivity experiments indicates that high-risk HCC15/H226 tumour cells and cell line-derived xenograft models are more resistant to vinorelbine treatment. Furthermore, the combination of chemotherapy with transforming growth factor-β inhibition augments antitumour responses in LUSC tumours. Our study provides valuable insights into prognosis stratification and the development of therapeutic strategies for LUSC.

Renal Protection of HWL-088and ZLY-032, Two Dual GPR40/PPARδ Agonists, in Adenine-Induced Renal Fibrosis Model

This research examined the potential of novel GPR40/PPARδ dual agonists, HWL-088 and ZLY-032, to protect the kidneys in a mouse model of adenine-induced renal fibrosis. Mice were given a diet containing 0.25 % adenine to develop renal fibrosis and then received different dosages of HWL-088 or ZLY-032. After being euthanized, tissue and serum samples were collected for morphological, histological, and molecular examination. Compared to the control group, mice fed adenine showed an increase in kidney-to-body weight ratio, serum creatinine, and urea levels. Hematoxylin and eosin staining revealed alleviated glomerulosclerosis, tubular dilation, and inflammatory cell infiltration in mice treated with HWL-088 or ZLY-032. Furthermore, Masson staining and immunohistochemistry demonstrated that these dual agonists protected against renal interstitial fibrosis and inflammation, corroborated by decreased expression levels of fibrosis-related proteins (TGF-β, Collα1, TIMP-1) and pro-inflammatory cytokines (TNF-α, IL-1β, IL-6). Accordingly, it can be inferred that GPR40/PPARδ dual agonists HWL-088 and ZLY-032 could yield significant renoprotective effects by inhibiting inflammation and fibrosis. Overall, these results may contribute to the development of novel therapeutic strategies for renal fibrosis.

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.

The fruit of Rosa odorata sweet var. gigantea (Coll. et Hemsl.) Rehd. et Wils attenuates chronic atrophic gastritis induced by MNNG and its potential mechanism

ETHNOPHARMACOLOGICAL RELEVANCE

Rosa odorata Sweet var. gigantea (Coll. et Hemsl.) Rehd. et Wils is a commonly utilized traditional medicine among the Yi nationality, also known as "Gugongguo", for the treatment of gastrointestinal disorders. Previous studies have indicated that the extract of Rosa odorata sweet var. gigantea (FOE) fruit has demonstrated a protective effect on the stomach; however, its impact on chronic atrophic gastritis (CAG) with severe disease remains unknown.

AIM OF THE STUDY

This study aimed to investigate the impact of FOE on CAG and its underlying mechanisms both in vitro and in vivo.

MATERIALS AND METHODS

By employing Ultra Performance Liquid Chromatography/Quadrupole-Time of Flight Mass Spectrometry (UPLC-QTOF-MS/MS) and network pharmacology, the primary active compounds and action targets of FOE were identified. In vitro, the impact of FOE on CAG was investigated through scratch, migration, and invasion assays. Subsequently, guided by network pharmacology, EMT and TGF-β signaling pathway-related proteins were assessed using Western blot and immunofluorescence experiments. Additionally, an in vivo CAG rat model was established to validate the effects of FOE and confirm its mechanism of action through hematoxylin-eosin (H&E), immunohistochemistry, Western blot, as well as untargeted metabolomics analysis of rat serum. It was observed that FOE inhibited scratch healing abilities, migration, invasion capabilities, as well as the expression of EMT-related proteins (E-cadherin, N-cadherin, Snail, Vimentin) in CAG model cells (MC cells), providing initial evidence for its efficacy.

RESULTS

Through the analysis of UPLC-QTOF-MS/MS, a total of 51 major compounds were identified in the FOE. Subsequent network pharmacological analysis suggested that FOE may regulate Epithelial mesenchymal transition (EMT) through the transforming growth factor β (TGF-β) pathway. Furthermore, experimental verification demonstrated that FOE inhibited the protein expression of TGF-β1 and its downstream protein Smad2/3 in vitro. In vivo findings also indicated similar mechanisms in MC cells, suggesting a reversal of the CAG process and significant inhibition of EMT and TGF-β signaling pathways. Additionally, untargeted metabolomics of rat serum confirmed the therapeutic effect of FOE on CAG and predicted its potential involvement in the arachidonic acid metabolic pathway.

CONCLUSION

This study initially demonstrated that FOE effectively reverses the process of EMT through the TGF-β1/Smad2/3 signaling pathway, thereby providing a therapeutic benefit for CAG.

Liver X Receptor-Growth Differentiation Factor 15 Activation Drives Profibrotic Changes in the Aqueous Outflow Tract of Uveitic Glaucoma

Cytomegalovirus (CMV)-induced anterior uveitis is linked to increased intraocular pressure, suggesting profibrotic changes in the eye's drainage system. Previous studies on the aqueous humor (AH) of patients with CMV uveitic glaucoma (UG) highlighted the activation of the liver X receptor (LXR) pathway, yet a potential that it has a role in increased intraocular pressure remained unelucidated. Herein, we explored the LXR pathway's role in AH outflow in UG. Global transcriptional analysis revealed that LXR activation primarily induces transforming growth factor-β signaling, with growth differentiation factor 15 (GDF-15), a growth factor in the transforming growth factor-β superfamily, being one of the most up-regulated genes in LXR-agonist-treated trabecular meshwork cells. GDF-15 levels showed a twofold expression in the AH of patients with UG (n = 44) compared with controls (n = 24; P = 0.024) and increased with more anti-glaucoma eyedrops and glaucoma surgeries (P < 0.05). LXRα/β and GDF-15 were found in human outflow tissue and were up-regulated by lipopolysaccharide and CMV infection. In an experimental endotoxin uveitis model, GDF-15 levels were up-regulated by the treatment with LXR agonists and lipopolysaccharide. In human trabecular meshwork cells, LXR agonists triggered actin stress fiber formation and α-smooth muscle actin expression, both reduced by GDF-15 neutralization. These results suggest that the LXR-GDF-15 pathway contributes to profibrotic changes in UG and plays a role in disease pathogenesis.

Signaling pathway mechanisms of circadian clock gene Bmal1 regulating bone and cartilage metabolism: a review

Circadian rhythm is ubiquitous in nature. Circadian clock genes such as Bmal1 and Clock form a multi-level transcription-translation feedback network, and regulate a variety of physiological and pathological processes, including bone and cartilage metabolism. Deletion of the core clock gene Bmal1 leads to pathological bone alterations, while the phenotypes are not consistent. Studies have shown that multiple signaling pathways are involved in the process of Bmal1 regulating bone and cartilage metabolism, but the exact regulatory mechanisms remain unclear. This paper reviews the signaling pathways by which Bmal1 regulates bone/cartilage metabolism, the upstream regulatory factors that control Bmal1, and the current Bmal1 knockout mouse models for research. We hope to provide new insights for the prevention and treatment of bone/cartilage diseases related to circadian rhythms.

UHRF1 promotes epithelial-mesenchymal transition mediating renal fibrosis by activating the TGF-β/SMAD signaling pathway

Renal fibrosis is widely recognized as the ultimate outcome of many chronic kidney diseases. The process of epithelial-mesenchymal transition (EMT) plays a critical role in the progression of fibrosis following renal injury. UHRF1, as a critical epigenetic regulator, may play an essential role in the pathogenesis and progression of renal fibrosis and EMT. However, the potential mechanisms remain to be elucidated. We aim to investigate the role of UHRF1 in EMT and renal fibrosis and to evaluate the potential benefits of Hinokitiol in preventing renal fibrosis. Based on data from the GEO and Nephroseq databases, UHRF1 exhibited high expression levels in the unilateral ureteral obstruction (UUO) model and in patients with nephropathy. Gene set enrichment analysis predicted that UHRF1 may function through the TGF-β signaling pathway in fibrosis. By establishing a TGF-β1-stimulated HK2 cell model and animal models of renal fibrosis induced by UUO and folic acid, we confirmed that UHRF1 was highly expressed in both in vitro and in vivo models of renal fibrosis. After knockdown of UHRF1 in vitro, we found that the TGF-β/SMAD signaling pathway was inhibited, renal tubular epithelial cell EMT was reduced and renal fibrosis was attenuated. Hinokitiol has been reported to reduce the expression of UHRF1 mRNA and protein. We observed that inhibition of UHRF1 with Hinokitiol ameliorated induced EMT and renal fibrosis by reducing SMAD2/3 phosphorylation in vivo and in vitro. Taken together, our data demonstrated that the upregulation of UHRF1 accelerated the EMT of renal tubular cells and renal fibrosis through the TGF-β/SMAD signaling pathway. Hinokitiol may ameliorate renal fibrosis by suppressing the expression of UHRF1 in the kidney.

Causal Inference and Annotation of Phosphoproteomics Data in Multiomics Cancer Studies

Protein phosphorylation plays a crucial role in regulating diverse biological processes. Perturbations in protein phosphorylation are closely associated with downstream pathway dysfunctions, whereas alterations in protein expression could serve as sensitive indicators of pathological status. However, there are currently few methods that can accurately identify the regulatory links between protein phosphorylation and expression, given issues like reverse causation and confounders. Here, we present Phoslink, a causal inference model to infer causal effects between protein phosphorylation and expression, integrating prior evidence and multiomics data. We demonstrated the feasibility and advantages of our method under various simulation scenarios. Phoslink exhibited more robust estimates and lower false discovery rate than commonly used Pearson and Spearman correlations, with better performance than canonical instrumental variable selection methods for Mendelian randomization. Applying this approach, we identified 345 causal links involving 109 phosphosites and 310 proteins in 79 lung adenocarcinoma (LUAD) samples. Based on these links, we constructed a causal regulatory network and identified 26 key regulatory phosphosites as regulators strongly associated with LUAD. Notably, 16 of these regulators were exclusively identified through phosphosite-protein causal regulatory relationships, highlighting the significance of causal inference. We explored potentially druggable phosphoproteins and provided critical clues for drug repurposing in LUAD. We also identified significant mediation between protein phosphorylation and LUAD through protein expression. In summary, our study introduces a new approach for causal inference in phosphoproteomics studies. Phoslink demonstrates its utility in potential drug target identification, thereby accelerating the clinical translation of cancer proteomics and phosphoproteomic data.

Emerging regulatory mechanisms and functions of biomolecular condensates: implications for therapeutic targets

Cells orchestrate their processes through complex interactions, precisely organizing biomolecules in space and time. Recent discoveries have highlighted the crucial role of biomolecular condensates-membrane-less assemblies formed through the condensation of proteins, nucleic acids, and other molecules-in driving efficient and dynamic cellular processes. These condensates are integral to various physiological functions, such as gene expression and intracellular signal transduction, enabling rapid and finely tuned cellular responses. Their ability to regulate cellular signaling pathways is particularly significant, as it requires a careful balance between flexibility and precision. Disruption of this balance can lead to pathological conditions, including neurodegenerative diseases, cancer, and viral infections. Consequently, biomolecular condensates have emerged as promising therapeutic targets, with the potential to offer novel approaches to disease treatment. In this review, we present the recent insights into the regulatory mechanisms by which biomolecular condensates influence intracellular signaling pathways, their roles in health and disease, and potential strategies for modulating condensate dynamics as a therapeutic approach. Understanding these emerging principles may provide valuable directions for developing effective treatments targeting the aberrant behavior of biomolecular condensates in various diseases.

Targeting CFTR restoring aggrephagy to suppress HSC activation and alleviate liver fibrosis

BACKGROUND AND AIMS

Multiple studies have shown that hepatic fibrosis, a progressive condition that represents the endpoint of various chronic liver diseases, is primarily marked by the extensive activation of hepatic stellate cells (HSCs). However, the exact impact of cystic fibrosis transmembrane conductance regulator (CFTR) on HSCs during the development of hepatic fibrosis remains unclear.

METHODS

In our study, we measured CFTR levels in tissue samples and in HSCs activated by TGF-β stimulation. We established mouse models of liver fibrosis using carbon tetrachloride (CCl4) and bile duct ligation (BDL). In vitro, we investigated the specific mechanisms of CFTR action in HSCs by exploring aggrephagy. We employed co-immunoprecipitation (co-IP) experiments to identify potential downstream targets of CFTR. Finally, through rescue experiments, we examined the impact of GTPase-activating protein - binding protein 1 (G3BP1) on CFTR-mediated activation of hepatic stellate cells.

RESULT

In activated HSCs induced by TGF-β, the reduction of CFTR, various liver fibrosis models, and fibrotic tissue samples were identified. In vitro functional experiments confirmed that CFTR promoted the expression of fibrosis-related markers and aggrephagy in HSCs. Mechanistically, we found that CFTR directly interacts with G3BP1, thereby further promoting the TGF-β/Smad2/3 pathway. The inhibition of G3BP1 caused by CFTR knockdown reduced extracellular matrix deposition, contributing to alleviating liver fibrosis.

CONCLUSION

We emphasize that CFTR activates aggrephagy and promotes HSC activation and hepatic fibrosis by targeting G3BP1, participating in the TGF-β/Smad2/3 signaling pathway. Overall, CFTR has been identified as a potential therapeutic target for liver fibrosis.

USP25 stabilizes STAT6 to promote IL-4-induced macrophage M2 polarization and fibrosis

As a leading cause of morbidity and mortality, fibrosis is the common pathway of various chronic inflammatory diseases in organs and causes death in a large number of patients. It can destroy the structure and function of organs and ultimately lead to organ failure, which is a major cause of disability and death in many diseases. However, the regulatory mechanism of organ fibrosis is not well clear and the lack of effective drugs and treatments, which seriously endangers human health and safety. In this study, we found that ubiquitin specific peptidases 25 (USP25) deficiency could protect mice from bleomycin (BLM)-induced pulmonary fibrosis and bile duct ligation (BDL)-induced liver fibrosis. Mechanistically, USP25 deficiency reduced the infiltration of M2 macrophages in the lungs and livers. USP25 inhibits signal transducer and activator of transcription 6 / peroxisome proliferator-activated receptor gamma (STAT6/PPAR-γ) signaling by reducing the K48 specific ubiquitination of STAT6, thereby promoting IL-4-induced M2 macrophages. Overall, our findings support that USP25 promotes the development of fibrosis by facilitating macrophage M2 polarization.

FMNL3 Promotes Migration and Invasion of Breast Cancer Cells via Inhibiting Rad23B-Induced Ubiquitination of Twist1

Breast cancer is a heterogeneous malignant tumor, and its high metastasis rate depends on the abnormal activation of cell dynamics. Formin-like protein 3 (FMNL3) plays an important role in the formation of various cytoskeletons that participate in cell movement. The objective of this study was to explore the function of FMNL3 in breast cancer progression and endeavor to reveal the molecular mechanism of this phenomenon. We found that FMNL3 was abnormally highly expressed in aggressive breast cancer cells and tissues, and it significantly inhibited E-cadherin expression. FMNL3 could specifically interact with Twist1 rather than other epithelial-mesenchymal transition transcription factors (EMT-TFs). We also found that FMNL3 enhanced the repressive effect of Twist1 on CDH1 transcription in breast cancer cells. Further mechanism studies showed that FMNL3 suppressed the ubiquitin degradation of Twist1 by inhibiting the interaction between Twist1 and Rad23B, the ubiquitin transfer protein of Twist1. In vitro functional experiments, it was confirmed that FMNL3 promoted the migration and invasion of breast cancer cells by regulating Twist1. Furthermore, Twist1 could directly bind to the fmnl3 promoter to facilitate FMNL3 transcription. To conclude, this study indicated that FMNL3 acted as a pro-metastasis factor in breast cancer by promoting Twist1 stability to suppress CDH1 transcription.

Epigenetic therapeutics attenuate kidney injury and fibrosis by restoring the expression of epigenetically reprogrammed fibrogenic genes and signaling pathways

Kidney fibrosis is a commonly observed pathological condition during development of chronic kidney disease. Therapeutic options currently available are effective only in slowing the progression of kidney fibrosis and there is no cure for this disease. Aberrant expression and excessive accumulation of extracellular matrix (ECM) proteins in the peritubular space is a characteristic pathological feature of fibrotic kidney. However, the molecular basis of aberrant regulation of fibrotic genes in kidneys is not clear. In this context, this study aimed to evaluate the role of epigenetic reprogramming in kidney fibrosis. Folic acid (FA)-induced acute kidney injury (AKI) and kidney fibrosis in mice as an in vivo model and long-term arsenic or FA-exposed fibrogenic HK-2 cells as an in vitro model were used to evaluate the role of DNA methylation and histone modifications in fibrosis. DNA demethylating agent 5aza2 deoxycytidine (5-aza-2-dC) and histone deacetylase inhibitor Trichostatin A (TSA) were used to treat FA-injected mice. Results of histopathological and immunofluorescence staining of kidney tissue, serum albumin- creatinine levels, body weight, and gene expression analysis revealed significant protective effects of 5-aza-2-dC and TSA in FA-induced AKI and fibrosis. Insignificant change in the expression of N-cadherin whereas a significant decrease in E-cadherin as well as an increase in the expression of Vimentin and α-SMA suggest partial EMT associated with fibrosis. Aberrant expression of epithelial-mesenchymal-transition (EMT) and ECM-regulators (MMP2, Smad7, and TIMP3) as well as fibrogenic signaling pathways (Notch, TGF-beta, and Wnt signaling), and their restoration by 5-aza-2-dC and TSA treatments suggest epigenetic reprogramming of these genes and signaling pathways during FA-induced fibrosis. In summary, this study provides new information on the role of epigenetic reprogramming of fibrogenic genes and signaling pathways during the development of kidney fibrosis. Attenuation of fibrosis after 5-aza-2-dC and TSA treatments suggest the promise of these epigenetic-based therapeutics in the clinical management of this disease.

NSUN5 Facilitates Hepatocellular Carcinoma Progression by Increasing SMAD3 Expression

Hepatocellular carcinoma (HCC) is characterized by frequent intrahepatic and distant metastases, resulting in a poor prognosis for patients. Epithelial-mesenchymal transition (EMT) plays a pivotal role in this process. However, the expression of NOP2/Sun RNA methyltransferase 5 (NSUN5) in HCC and its role in mediating EMT remain poorly understood. In this study, clinicopathological analyses are conducted across multiple independent HCC cohorts and induced tumor formation in Nsun5-knockout mice. The findings reveal an upregulation of NSUN5 expression in tumor tissues; conversely, the absence of Nsun5 hinders the malignant progression of HCC, indicating that NSUN5 may serve as a significant oncogene in HCC. Furthermore, elevated levels of NSUN5 enhance EMT processes within HCC cells. NSUN5-knockout cells exhibit reduced invasion and migration capabilities under both in vivo and in vitro conditions, while overexpression of NSUN5 yields opposing effects. Mechanistically, high levels of NSUN5 promote the enrichment of trimethylated histone H3 at lysine 4 (H3K4me3) at the promoter region of SMAD3 through recruitment of the WDR5, thereby facilitating HCC metastasis via SMAD3-mediated EMT pathways. Collectively, this study identifies NSUN5 as a novel driver of metastasis in HCC and provides a theoretical foundation for potential therapeutic strategies against this malignancy.

Impact of immunosuppressants on tumor pulmonary metastasis: new insight into transplantation for hepatocellular carcinoma

Pulmonary metastasis is a life-threatening complication for patients with hepatocellular carcinoma (HCC) undergoing liver transplantation (LT). In addition to the common mechanisms underlying tumor metastasis, another inevitable factor is that the application of immunosuppressive agents, including calcineurin inhibitors (CNIs) and rapamycin inhibitors (mTORis), after transplantation could influence tumor recurrence and metastasis. In recent years, several studies have reported that mTORis, unlike CNIs, have the capacity to modulate the tumorigenic landscape post-liver transplantation by targeting metastasis-initiating cells and reshaping the pulmonary microenvironment. Therefore, we focused on the effects of immunosuppressive agents on the lung metastatic microenvironment and how mTORis impact tumor growth in distant organs. This revelation has provided profound insights into transplant oncology, leading to a renewed understanding of the use of immunosuppressants after LT for HCC.

Adipose-derived stem cell exosomes attenuates myofibroblast transformation via inhibiting autophagy through TGF-β/Smad2 axis in oral submucosal fibrosis

Oral submucous fibrosis (OSF) is a precancerous condition that poses substantial health risks. OSF is mainly caused by betel nut chewing behavior, but its pathogenesis is still unclear and there is no effective treatment strategy. The transformation of fibroblasts to myofibroblast is the key pathological change in the development of OSF. We isolated fibroblasts from human oral mucosa and induced them into myofibroblasts by arecoline, during which autophagy was significantly activated. Here, we found that adipose-derived stem cell exosomes (ADSCs-EXO) could inhibit autophagy to regulate myofibroblast phenotype, and transcriptome sequencing analysis suggested that this process is closely related to the TGF-β pathway. The interplay between autophagy and TGF-β pathway was examined through modulation the two with autophagy activators and inhibitors, TGF-β receptor activators and inhibitors. Results showed that in vitro, the TGF-β/Smad2 pathway augmented autophagy and promoted myofibroblast transformation. The transcriptome information of ADSCs-EXO showed that it contains a large number of miRNAs. Among them, miR-125a-5p could target Smad2. In vivo, injection of ADSCs-EXO alleviated OSF in mice, during which TGF-β and autophagy signals were inhibited. We suggested that ADSCs-EXO could inhibit myofibroblast transformation via inhibiting autophagy through TGF-β/Smad2 axis in OSF, providing new insights for autophagy-based intervention strategies.

Genetic predisposition meets cytokine imbalance: the influence of TNF-α (-308) polymorphism and TGF-β levels in pediatric acute lymphoblastic leukemia in Egypt

Evading apoptosis fuels the aggressive nature of acute lymphoblastic leukemia (ALL). This study explored the potential roles of TNF-α, a pro-apoptotic cytokine, and TGF-β, a pro-proliferative factor, in the risk of developing ALL in Egyptian children. We investigated the TNF-α rs1800629 polymorphism and serum TGF-β levels in 100 ALL patients and 100 healthy controls. Notably, specific variations in TNF-α (GA, AA genotypes, and dominant model) were associated with an increased risk of ALL, suggesting impaired apoptosis. Conversely, ALL patients exhibited significantly lower TGF-β levels, potentially promoting uncontrolled proliferation. Our findings suggest that lower TGF-β and the TNF-α (-308) dominant model are associated with an increased risk of ALL. Additionally, TGF-β demonstrated exceptional accuracy (AUC 0.995) as a potential marker, with 100% sensitivity and 96% specificity. These findings suggest that TNF-α and TGF-β may be associated with ALL susceptibility, though further research with larger and more diverse populations is necessary to confirm these results.

Selective translation of nuclear mitochondrial respiratory proteins reprograms succinate metabolism in AML development and chemoresistance

Mitochondrial adaptations dynamically reprogram cellular bioenergetics and metabolism and confer key properties for human cancers. However, the selective regulation of these mitochondrial responses remains largely elusive. Here, inspired by a genetic screening in acute myeloid leukemia (AML), we identify RAS effector RREB1 as a translational regulator and uncover a unique translation control system for nuclear-encoded mitochondrial proteins in human cancers. RREB1 deletion reduces mitochondrial activities and succinate metabolism, thereby damaging leukemia stem cell (LSC) function and AML development. Replenishing complex II subunit SDHD rectifies these deficiencies. Notably, inhibition of complex II re-sensitizes AML cells to venetoclax treatment. Mechanistically, a short RREB1 variant binds to a conserved motif in the 3' UTRs and cooperates with elongation factor eEF1A1 to enhance protein translation of nuclear-encoded mitochondrial mRNAs. Overall, our findings reveal a unique translation control mechanism for mitochondrial adaptations in AML pathogenesis and provide a potential strategy for targeting this vulnerability of LSCs.

Transforming growth factor-β1 is associated with inflammatory resolution via regulating macrophage polarization in lung injury model mice

OBJECTIVE

Ventilation is the main respiratory support therapy for acute respiratory distress syndrome, which triggers acute lung injury (ALI). Macrophage polarization is vital for the resolution of inflammation and tissue injury. We hypothesized that transforming growth factor (TGF)-β1 may attenuate inflammation and ventilator-induced ALI by promoting M2 macrophage polarization.

METHODS

C57BL/6 mice received 4-hour ventilation and extubation to observe the resolution of lung injury and inflammation. Lung vascular permeability, inflammation, and histological changes in the lungs were evaluated by bronchoalveolar lavage analysis, enzyme linked immunosorbent assay, hematoxylin and eosin staining, as well as transmission electron microscope. TGF-β1 cellular production and macrophage subsets were analyzed by flow cytometry. The relative expressions of targeted proteins and genes were measured by immunofuorescence staining, Western blot, and quantitative polymerase chain reaction.

RESULTS

High tidal volume-induced injury and inflammation were resolved at 3 days of post-ventilation (PV3d) to PV10d, with increased elastic fibers, proteoglycans, and collagen content, as well as higher TGF-β1 levels. M1 macrophages were increased in the acute phase, whereas M2a macrophages began to increase from PV1d to PV3d, as well as increased M2c macrophages from PV3d to PV7d. A single dose of rTGF-β1 attenuated lung injury and inflammation at end of ventilation with polymorphonuclear leukocyte apoptosis, while nTAb pretreatment induced the abnormal elevation of TGF-β1 that aggravated lung injury and inflammation due to the significant inhibition of M1 macrophages polarized to M2a, M2b, and M2c macrophages.

CONCLUSIONS

Precise secretion of TGF-β1-mediated macrophage polarization plays a crucial role in the resolution of ventilator-induced inflammatory lung injury.

Bushen Huoxue Recipe inhibits endometrial epithelial-mesenchymal transition through the transforming growth factor-β/nuclear factor kappa-B pathway to improve polycystic ovary syndrome-mediated infertility

OBJECTIVE

To investigate the target and mechanism of action of Bushen Huoxue Recipe (BSHX) for the treatment of infertility in polycystic ovary syndrome (PCOS), to provide a basis for the development and clinical application of herbal compounds.

METHODS

Prediction and validation of active ingredients and targets of BSHX for the treatment of PCOS by using network pharmacology-molecular docking technology. In an animal experiment, the rats were randomly divided into four groups (control group, model group, BSHX group, metformin group, n = 16 in each group), and letrozole combined with high-fat emulsion gavage was used to establish a PCOS rat model. Body weight, vaginal smears, and number of embryos were recorded for each group of rats. Hematoxylin-eosin (HE) staining was used to observe the morphological changes of ovarian and endometrial tissues, and an enzyme-linked immunosorbent assay (ELISA) was used to detect the serum inflammatory factor levels. Expression levels of transforming growth factor-β (TGF-β), transforming growth factor beta activated kinase 1 (TAK1), nuclear factor kappa-B (NF-κB), Vimentin, and E-cadherin proteins were measured by western blot (WB).

RESULTS

Ninety active pharmaceutical ingredients were obtained from BSHX, involving 201 protein targets, of which 160 were potential therapeutic targets. The active ingredients of BSHX exhibited lower binding energy with tumor necrosis factor-α (TNF-α), TGF-β, TAK1, and NF-κB protein receptors (< -5.0 kcal/mol). BSHX significantly reduced serum TNF-α levels in PCOS rats (p < .01), effectively regulated the estrous cycle, restored the pathological changes in the ovary and endometrium, improved the pregnancy rate, and increased the number of embryos. The results of WB suggested that BSHX can down-regulate protein expression levels of TGF-β and NF-κB in endometrial tissue (p < .05), promote the expression level of E-cadherin protein (p < .001), intervene in the endometrial epithelial-mesenchymal transition (EMT) process.

CONCLUSIONS

TGF-β, TAK1, NF-κB, and TNF-α are important targets of BSHX for treating infertility in PCOS. BSHX improves the inflammatory state of PCOS, intervenes in the endometrial EMT process through the TGF-β/NF-κB pathway, and restores endometrial pathological changes, further improving the pregnancy outcome in PCOS.

Inulin alleviates GenX-induced intestinal injury in mice by modulating the MAPK pathway, cell cycle, and cell adhesion proteins

GenX, a substitute for perfluorooctanoic acid, has demonstrated potential enterotoxicity. The enterotoxic effects of GenX and effective interventions need further investigation. In the present study, the mice were administered GenX (2 mg/kg/day) with or without inulin supplementation (5 g/kg/day) for 12 weeks. Histopathological assessments revealed that GenX induced colonic gland atrophy, inflammatory cell infiltration, a reduction in goblet cell numbers, and decreased mucus secretion. Furthermore, a significant decrease in the protein levels of ZO-1, occludin, and claudin-5 indicated compromised barrier integrity. Transcriptomic analysis identified 2645 DEGs, which were mapped to 39 significant pathways. The TGF-β, BMP6, and β-catenin proteins were upregulated in the intestinal mucosa following GenX exposure, indicating activation of the TGF-β pathway. Conversely, the protein expression of PAK3, CyclinD2, contactin1, and Jam2 decreased, indicating disruptions in cell cycle progression and cell adhesion. Inulin cotreatment ameliorated these GenX-induced alterations, partially through modulating the MAPK pathway, as evidenced by the upregulation of the cell cycle and cell adhesion proteins. Collectively, these findings suggested that GenX exposure triggered intestinal injury in mice by activating the TGF-β pathway and disrupting proteins crucial for the cell cycle and cell adhesion, whereas inulin supplementation mitigated this injury by modulating the MAPK pathway.

CAF-secreted LOX promotes PD-L1 expression via histone Lactylation and regulates tumor EMT through TGFβ/IGF1 signaling in gastric Cancer

In gastric cancer treatment, cancer-associated fibroblasts (CAF) may significantly influence the efficacy of immune checkpoint inhibitors by modulating PD-L1 expression. However, the precise mechanisms remain unclear. This study aims to explore the relationship between CAF and PD-L1 expression, providing new insights for improving PD-L1-targeted therapies. Using primary fibroblasts, transcriptome sequencing, ChIP-qPCR, and a lung metastasis model, we discovered that CAF secrete lysyl oxidase (LOX), which activates the TGFβ signaling pathway in gastric cancer cells, thereby promoting insulin-like growth factor 1(IGF1) expression. Upregulation of IGF1 enhances gastric cancer cell migration, epithelial-mesenchymal transition (EMT), and glycolysis. Additionally, we found that lactate accumulation leads to lysine 18 lactylation on histone H3 (H3K18la), which enriches at the PD-L1 promoter region, thus promoting PD-L1 transcription. These findings suggest that CAF may diminish the effectiveness of PD-1/PD-L1 blockade immunotherapy through LOX-induced glycolysis and lactate accumulation. Consequently, we have constructed a model of the interactions among CAF, lactate, and PD-L1 in gastric cancer progression, providing new experimental evidence for PD-L1-based immunotherapy.

A novel interaction between RNA m6A methyltransferase METTL3 and RREB1

Regulation of gene expression is achieved through the modulation of regulatory inputs both pre- and post-transcriptionally. Methyltransferase-like 3 (METTL3) is a key player in pre-mRNA processing, actively catalyzing N6-methyladenosine (m6A). Among the most enriched mRNA targets of METTL3 is the Ras Responsive Element Binding Protein 1 (RREB1), a transcription factor which functions to govern cell fate, proliferation and DNA repair. Here, we show a novel interaction between METTL3 and RREB1. Further examination of this interaction indicates that METTL3's N-terminus is the primary interacting domain. Our findings uncover a novel interacting partner of METTL3, providing further insights into METTL3's regulatory network.

LRP1 Repression by SNAIL Results in ECM Remodeling in Genetic Risk for Vascular Diseases

BACKGROUND

Genome-wide association studies implicate common genetic variations in the LRP1 (low-density lipoprotein receptor-related protein 1 gene) locus at risk for multiple vascular diseases and traits. However, the underlying biological mechanisms are unknown.

METHODS

Fine mapping analyses included Bayesian colocalization to identify the most likely causal variant. Human induced pluripotent stem cells were genome-edited using CRISPR-Cas9 (Clustered Regularly Interspaced Short Palindromic Repeats-CRISPR associated protein 9) to delete or modify candidate enhancer regions and generate LRP1 knockout cell lines. Cells were differentiated into smooth muscle cells through a mesodermal lineage. Transcription regulation was assessed using luciferase reporter assay, transcription factor knockdown, and chromatin immunoprecipitation. Phenotype changes in cells were conducted using cellular assays, bulk RNA sequencing, and mass spectrometry.

RESULTS

Multitrait colocalization analyses pointed at rs11172113 as the most likely causal variant in LRP1 for fibromuscular dysplasia, migraine, pulse pressure, and spontaneous coronary artery dissection. We found the rs11172113-T allele to associate with higher LRP1 expression. Genomic deletion in induced pluripotent stem cell-derived smooth muscle cells supported rs11172113 to locate in an enhancer region regulating LRP1 expression. We found transcription factors MECP2 (methyl CpG binding protein 2) and SNAIL (Zinc Finger Protein SNAI1) to repress LRP1 expression through an allele-specific mechanism, involving SNAIL interaction with disease risk allele. LRP1 knockout decreased induced pluripotent stem cell-derived smooth muscle cell proliferation and migration. Differentially expressed genes were enriched for collagen-containing extracellular matrix and connective tissue development. LRP1 knockout and deletion of rs11172113 enhancer showed potentiated canonical TGF-β (transforming growth factor beta) signaling through enhanced phosphorylation of SMAD2/3 (Mothers against decapentaplegic homolog 2/3). Analyses of the protein content of decellularized extracts indicated partial extracellular matrix remodeling involving enhanced secretion of CYR61 (cystein rich angiogenic protein 61), a known LRP1 ligand involved in vascular integrity and TIMP3 (Metalloproteinase inhibitor 3), implicated in extracellular matrix maintenance and also known to interact with LRP1.

CONCLUSIONS

Our findings support allele-specific LRP1 expression repression by the endothelial-to-mesenchymal transition regulator SNAIL. We propose decreased LRP1 expression in smooth muscle cells to remodel the extracellular matrix enhanced by TGF-β as a potential mechanism of this pleiotropic locus for vascular diseases.

Mesenchymal Stem Cells and Their Derived Exosomes Mitigated Hepatic Cirrhosis in Rats by Altering the Expression of miR-23b and miR-221

Background

The therapeutic effect of mesenchymal stem cells (MSCs) in liver cirrhosis is limited by their entrapment in the pulmonary vessels. Thus, the use of MSC-derived exosomes has become a promising strategy. The current work aimed to compare the role of human umbilical cord blood-MSCs (hUCB-MSCs) and their derived exosomes in the alleviation of liver cirrhosis focusing on the role of miR-23b and miR-221 and their direct effectors in inflammatory and autophagic pathways.

Methods

Rats were divided into six groups normal controls (negative control), liver cirrhosis group (positive control), liver cirrhotic rats that received conditioned media, liver cirrhotic rats that received hUCB-MSCs, cirrhotic rats that received exosomes, and cirrhotic rats that received both hUCB-MSCs and exosomes. The messenger RNA expression of transforming growth factor-β (TGF-β), Matrix metalloproteinase 9 (MMP 9), fibronectin, collagen type-1 (col1), alpha-smooth muscle actin (α-SMA), Suppressor of Mothers Against Decapentaplegic (SMAD) 2 and 7, Beclin, P62, and light chain 3 (LC3) were evaluated by quantitative real-time polymerase chain reaction. Immunohistochemical staining for Beclin, P62, and LC3 was performed.

Results

The treatment of cirrhotic rats with hUCB-MSCs, exosomes, or the combination of them significantly downregulated miRNA-221, fibronectin, collagen I, α-SMA, Smad2 (P<0.001, for each), and P62 (P=0.032, P<0.001, P<0.001, respectively). Additionally, the treatment of cirrhotic rats with hUCB-MSCs, exosomes, or the combination of them significantly upregulated mTOR, Beclin, LC3, and Smad7 (P<0.001, for each) and miRNA-23 (P=0.021, P<0.001, P<0.001, respectively).

Conclusion

hUCB-MSCs and their derived exosomes ameliorated liver cirrhosis by anti-inflammatory and anti-fibrotic effects besides modulation of autophagy. The exosomes had a better improvement effect either alone or combined with hUCB-MSCs, as proved by improvement in liver function tests, and molecular, histopathological, and immunohistochemical profiles.

MAP3K19 Promotes the Progression of Tuberculosis-Induced Pulmonary Fibrosis Through Activation of the TGF-β/Smad2 Signaling Pathway

Tuberculosis-induced pulmonary fibrosis (PF) is a chronic, irreversible interstitial lung disease, which severely affects lung ventilation and air exchange, leading to respiratory distress, impaired lung function, and ultimately death. As previously reported, epithelial-mesenchymal transition (EMT) and fibrosis in type II alveolar epithelial cells (AEC II) are two critical processes that contributes to the initiation and progression of tuberculosis-related PF, but the underlying pathological mechanisms remain unclear. In this study, through performing Real-Time quantitative PCR (RT-qPCR), Western blot, immunohistochemistry, and immunofluorescence staining assay, we confirmed that the expression levels of EMT and fibrosis-related biomarkers were significantly increased in lung tissues with tuberculosis-associated PF in vivo and Mycobacterium bovis Bacillus Calmette-Guérin (BCG) strain-infected AEC II cells in vitro. Besides, we noticed that the mitogen-activated protein kinase 19 (MAP3K19) was aberrantly overexpressed in PF models, and silencing of MAP3K19 significantly reduced the expression levels of fibronectin, collagen type I, and alpha-smooth muscle actin to decrease fibrosis, and upregulated E-cadherin and downregulated vimentin to suppress EMT in BCG-treated AEC II cells. Then, we uncovered the underlying mechanisms and found that BCG synergized with MAP3K19 to activate the pro-inflammatory transforming growth factor-beta (TGF-β)/Smad2 signal pathway in AEC II cells, and BCG-induced EMT process and fibrosis in AEC II cells were all abrogated by co-treating cells with TGF-β/Smad2 signal pathway inhibitor LY2109761. In summary, our results uncovered the underlying mechanisms by which the MAP3K19/TGF-β/Smad2 signaling pathway regulated EMT and fibrotic phenotypes of AEC II cells to facilitate the development of tuberculosis-associated PF, and these findings will provide new ideas and biomarkers to ameliorate tuberculosis-induced PF in clinic.

Research advances in signaling pathways related to the malignant progression of HSIL to invasive cervical cancer: A review

The progression of high-grade squamous intraepithelial lesion (HSIL) to invasive cervical cancer (ICC) is a complex process involving persistent human papillomavirus (HPV) infection and changes in signal transduction regulation, energy and material metabolism, cell proliferation, autoimmune, and other biological process in vaginal microenvironment and immune microenviroment. Signaling pathways are a series of interacting molecules in cells that regulate various physiological functions of cells, such as growth, differentiation, metabolism, and death. In the progression of HSIL to ICC, abnormal activation or inhibition in signaling pathways plays an essensial role. This review presented some signaling pathways related to the malignant progression of HSIL to ICC, including p53, Rb, PI3K/AKT/mTOR, Wnt/β-catenin, Notch, NF-κB, MAPK, TGF-β, JAK-STAT, Hippo, and Hedgehog. The molecular mechanisms involved in the biological process of pathway regulation were also analyzed, in order to illustrate the molecular pathway of HSIL progression to ICC and provide references for the development of more effective prevention and treatment methods.

TGF-β and RAS jointly unmask primed enhancers to drive metastasis

Epithelial-to-mesenchymal transitions (EMTs) and extracellular matrix (ECM) remodeling are distinct yet important processes during carcinoma invasion and metastasis. Transforming growth factor β (TGF-β) and RAS, signaling through SMAD and RAS-responsive element-binding protein 1 (RREB1), jointly trigger expression of EMT and fibrogenic factors as two discrete arms of a common transcriptional response in carcinoma cells. Here, we demonstrate that both arms come together to form a program for lung adenocarcinoma metastasis and identify chromatin determinants tying the expression of the constituent genes to TGF-β and RAS inputs. RREB1 localizes to H4K16acK20ac marks in histone H2A.Z-loaded nucleosomes at enhancers in the fibrogenic genes interleukin-11 (IL11), platelet-derived growth factor-B (PDGFB), and hyaluronan synthase 2 (HAS2), as well as the EMT transcription factor SNAI1, priming these enhancers for activation by a SMAD4-INO80 nucleosome remodeling complex in response to TGF-β. These regulatory properties segregate the fibrogenic EMT program from RAS-independent TGF-β gene responses and illuminate the operation and vulnerabilities of a bifunctional program that promotes metastatic outgrowth.

Mitochondrial dysfunction is a key link involved in the pathogenesis of sick sinus syndrome: a review

Sick sinus syndrome (SSS) is a grave medical condition that can precipitate sudden death. The pathogenesis of SSS remains incompletely understood. Existing research postulates that the fundamental mechanism involves increased fibrosis of the sinoatrial node and its surrounding tissues, as well as disturbances in the coupled-clock system, comprising the membrane clock and the Ca2+ clock. Mitochondrial dysfunction exacerbates regional tissue fibrosis and disrupts the functioning of both the membrane and calcium clocks. This plays a crucial role in the underlying pathophysiology of SSS, including mitochondrial energy metabolism disorders, mitochondrial oxidative stress damage, calcium overload, and mitochondrial quality control disorders. Elucidating the mitochondrial mechanisms involved in the pathophysiology of SSS and further investigating the disease's mechanisms is of great significance.

Y-27632 targeting ROCK1&2 modulates cell growth, fibrosis and epithelial-mesenchymal transition in hyperplastic prostate by inhibiting β-catenin pathway

Benign prostatic hyperplasia (BPH) is a prevalent condition affecting the male urinary system, with its molecular mechanisms of pathogenesis remaining unclear. Y-27632, a non-isoform-selective Rho kinase inhibitor, has shown therapeutic potential in various diseases but its effects on static factors and fibrosis in BPH remain unexplored. This study investigated human prostate tissues, human prostate cell lines, and BPH rat model using immunofluorescence, flow cytometry, quantitative reverse transcription polymerase chain reaction, western blotting, and cell counting kit-8. ROCK1 and ROCK2 were significantly up-regulated in BPH tissues, correlating with clinical parameters. Y-27632 targeted the inhibition of ROCK1 & ROCK2 expression and inhibited cell proliferation, fibrosis, epithelial-mesenchymal transition (EMT), while induced cell apoptosis in a dose-dependent manner. Moreover, knockdown of either ROCK isoform inhibited fibrosis and EMT, induced apoptosis, while ROCK overexpression had the opposite effects. ROCK downregulation inhibited the β-catenin signaling pathway (such as C-MYC, Snail and Survivin) and decreased β-catenin protein stability, while inhibiting TGF-β/Smad2/3 signaling. At the in vivo level, Y-27632 reversed prostatic hyperplasia and fibrosis in BPH model rats to some extent. Our study sheds light on the therapeutic potential of Y-27632 in regulating prostate cell growth, fibrosis and EMT, and demonstrates for the first time the regulatory effect of ROCK isoforms on prostate cells, providing the basis for future research of ROCK isoform-selective inhibitors.

An In Situ Sustained-Release Chitosan Hydrogel to Attenuate Renal Fibrosis by Retaining Klotho Expression

Klotho (KLO) is an anti-fibrotic protein expressed in the kidneys and has been decreasing in the development of renal fibrosis (RF). However, restoring the decline in KLO levels remains a great challenge during RF treatment. Herein, an injectable KLO-loaded chitosan (CS) hydrogel (KLO-Gel) is designed to achieve localized and prolonged release of KLO in the RF treatment. KLO-Gel was prepared by cross-linking CS with β-glycerophosphate (β-GP), followed by rapid (within 3 min) thermosensitive gelation at 37 °C. Furthermore, KLO-Gel exhibited a slow and sustained release (over 14 d) of KLO both in PBS and in the kidneys of mice with unilateral ureter obstruction (UUO). A single local injection of KLO-Gel into the renal capsule of UUO mice was more effective at reducing RF (i.e., maintaining renal function and tissue structure, alleviating extracellular matrix accumulation, and inhibiting the TGF-β1/Smad2/3 signaling pathway) over a 14-d period than daily intraperitoneal injections of free KLO or captopril. Crucially, CS was found to induce endogenous KLO secretion, highlighting the added value of using CS in RF treatment. Overall, this study demonstrated that KLO-Gel enhanced the anti-fibrotic efficacy of KLO while minimizing its off-target toxicity, and its clinical potential awaits further validation.

Decoding tumor-fibrosis interplay: mechanisms, impact on progression, and innovative therapeutic strategies

Malignant tumors are a category of diseases that possess invasive and metastatic capabilities, with global incidence and mortality rates remaining high. In recent years, the pivotal role of fibrosis in tumor progression, drug resistance, and immune evasion has increasingly been acknowledged. Fibrosis enhances the proliferation, migration, and invasion of tumor cells by modifying the composition and structure of the extracellular matrix, thereby offering protection for immune evasion by tumor cells. The activation of cancer-associated fibroblasts (CAFs) plays a significant role in this process, as they further exacerbate the malignant traits of tumors by secreting a variety of cytokines and growth factors. Anti-fibrotic tumor treatment strategies, including the use of anti-fibrotic drugs and inhibition of fibrosis-related signaling pathways such as Transforming Growth Factor-β (TGF-β), have demonstrated potential in delaying tumor progression and improving the effectiveness of chemotherapy, targeted therapy, and immunotherapy. In the future, by developing novel drugs that target the fibrotic microenvironment, new therapeutic options may be available for patients with various refractory tumors.

TGF-β induces an atypical EMT to evade immune mechanosurveillance in lung adenocarcinoma dormant metastasis

The heterogeneity of epithelial-to-mesenchymal transition (EMT) programs is manifest in the diverse EMT-like phenotypes occurring during tumor progression. However, little is known about the mechanistic basis and functional role of specific forms of EMT in cancer. Here we address this question in lung adenocarcinoma (LUAD) cells that enter a dormancy period in response to TGF-β upon disseminating to distant sites. LUAD cells with the capacity to enter dormancy are characterized by expression of SOX2 and NKX2-1 primitive progenitor markers. In these cells, TGF-β induces growth inhibition accompanied by a full EMT response that subsequently transitions into an atypical mesenchymal state of round morphology and lacking actin stress fibers. TGF-β induces this transition by driving the expression of the actin-depolymerizing factor gelsolin, which changes a migratory, stress fiber-rich mesenchymal phenotype into a cortical actin-rich, spheroidal state. This transition lowers the biomechanical stiffness of metastatic progenitors, protecting them from killing by mechanosensitive cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells. Inhibiting this actin depolymerization process clears tissues of dormant metastatic cells. Thus, LUAD primitive progenitors undergo an atypical EMT as part of a strategy to evade immune-mediated elimination during dormancy. Our results provide a mechanistic basis and functional role of this atypical EMT response of LUAD metastatic progenitors and further illuminate the role of TGF-β as a crucial driver of immune evasive metastatic dormancy.

M1 macrophages deliver CASC19 via exosomes to inhibit the proliferation and migration of colon cancer cells

Colorectal cancer (CRC) continues to be one of the leading causes of cancer-related death worldwide. Exosomes have been established to play an important role in intercellular communication and that long non-coding RNA (lncRNA) CASC19 is enriched within M1 macrophage-derived exosomes (M1-exo). However, the biological functions and underlying molecular mechanisms of exosomal CASC19 from macrophages on CRC remain unknown. Cell proliferation and migration were evaluated by MTS and transwell assays. The exosomes were characterized by western blot, nanoparticle tracking analysis (NTA) and electron microscope imaging. The expression levels of CASC19 and its putative target miR-410-3p were quantified by reverse-transcription polymerase chain reaction (RT-qPCR). The interaction between CASC19 and miR-410-3p was detected by the pull-down assay. We found that the non-contact inhibition of M1 macrophages on the proliferation of colon cancer cells is largely dependent on the CASC19 released from M1 exosomes. M1 exosomes successfully delivered CASC19 to colon cancer cells, exerting an inhibitory effect on cell proliferation and migration. The exosomes secreted by M1 cells with CASC19 knockdown showed less inhibition effect on cell proliferation and migration. Mechanically, CASC19 exerted an inhibitory effect on colon cancer cells by sponging miR-410-3p via tube morphogenesis and TGF-β signaling pathway. We first proved that CASC19 in M1 macrophages is delivered into colon cancer cells via exosomes, exerting an inhibitory effect on their proliferation and migration by sponging miR-410-3p. The study may provide mechanistic insights into the roles of lncRNAs in CRC progression and a potential therapeutic target for the treatment of CRC.

m6A modification in non-coding RNAs: Mechanisms and potential therapeutic implications in fibrosis

N6-methyladenosine (m6A) is one of the most prevalent and reversible forms of RNA methylation, with increasing evidence indicating its critical role in numerous physiological and pathological processes. m6A catalyzes messenger RNA(mRNA) as well as regulatory non-coding RNAs (ncRNAs), such as microRNAs, long non-coding RNAs, and circular RNAs. This modification modulates ncRNA fate and cell functions in various bioprocesses, including ncRNA splicing, maturity, export, and stability. Key m6A regulators, including writers, erasers, and readers, have been reported to modify the ncRNAs involved in fibrogenesis. NcRNAs affect fibrosis progression by targeting m6A regulators. The interactions between m6A and ncRNAs can influence multiple cellular life activities. In this review, we discuss the impact of the interaction between m6A modifications and ncRNAs on the pathological mechanisms of fibrosis, revealing the possibility of these interactions as diagnostic markers and therapeutic targets in fibrosis.

The correlation between cancer stem cells and epithelial-mesenchymal transition: molecular mechanisms and significance in cancer theragnosis

The connections between cancer stem cells (CSCs) and epithelial-mesenchymal transition (EMT) is critical in cancer initiation, progression, metastasis, and therapy resistance, making it a focal point in cancer theragnosis. This review provides a panorama of associations and regulation pathways between CSCs and EMT, highlighting their significance in cancer. The molecular mechanisms underlined EMT are thoroughly explored, including the involvement of key transcription factors and signaling pathways. In addition, the roles of CSCs and EMT in tumor biology and therapy resistance, is further examined in this review. The clinical implications of CSCs-EMT interplay are explored, including identifying mesenchymal-state CSC subpopulations using advanced research methods and developing targeted therapies such as inhibitors and combination treatments. Overall, understanding the reciprocal relationship between EMT and CSCs holds excellent potential for informing the development of personalized therapies and ultimately improving patient outcomes.

Single-cell RNA sequencing of OSCC primary tumors and lymph nodes reveals distinct origin and phenotype of fibroblasts

Desmoplasia in fibroblasts within metastatic lymph nodes (MLNs) serves as an indicator of extranodal extension (ENE), which led mortality in oral squamous cell carcinoma (OSCC). However, systematic studies on fibroblasts in MLNs are lacking. Therefore, this study characterized the differences in phenotype, function, and origin of fibroblasts between primary tumors (PTs) and lymph nodes (LNs) in OSCC. We generated single-cell maps of PTs and paired MLNs and draining LNs from three OSCC patients. The transcriptomic atlas, pseudotime analysis, intercellular communication networks and enrichment analysis of the single cells were characterized. Phenotype and function heterogeneity of fibroblast cells between PTs and MLNs were further verified in vitro. Among 44,052 fibroblasts, we identified two distinct subpopulations of cancer-associated myofibroblastic cells (mCAFs): RGS4+ mCAF1 and COMP + mCAF2. Notably, they exhibited distinct distributions, with mCAF1 predominantly localized in the PTs and mCAF2 in the MLNs. Moreover, pseudotime analysis revealed their distinct origins: mCAF1 originated from inherent normal myofibroblastic cells in the PT, whereas mCAF2 originated from fibroblastic reticular cells in the LNs. Further functional experiments using primary fibroblasts revealed that, compared to mCAF1, mCAF2 in MLNs exhibited weaker crosstalk with immune cells but enhanced extracellular matrix activity, which is closely linked to ENE formation in OSCC. Additionally, we identified two fibroblast subgroups in a transforming state, indicating a potential epithelial-mesenchymal transition. Our research offers profound insights into the heterogeneity of fibroblasts between the PT and MLN in OSCC, serving as an essential resource for future drug discovery endeavors.

Targeting PYK2, entrectinib allays anterior subcapsular cataracts in mice by regulating TGFβ2 signaling pathway

BACKGROUND

Fibrosis cataract occurs in patients receiving cataract extraction. Still, no medication that can cure the disease exists in clinical. This study aims to investigate the effects and mechanisms of Entrectinib on fibrotic cataract in vitro and in vivo.

METHODS

The human lens cells line SRA 01/04 and C57BL/6J mice were applied in the study. Entrectinib was used in animals and cells. Cataract severity was assessed by slit lamp and Hematoxylin and Eosin staining. Expression of alpha-smooth muscle actin, fibronectin, and collagen I were examined by real-time quantitative PCR, western blotting, and immunofluorescence. Cell proliferation was evaluated by Cell Counting Kit-8. Cell migration was measured by wound healing and transwell assays. Molecular docking, Drug Affinity Responsive Target Stability, and Cellular Thermal Shift Assay were applied to seek and certify the target of Entrectinib treating fibrosis cataract.

RESULTS

Entrectinib can ameliorate fibrotic cataract in vitro and in vivo. At the RNA and the protein levels, the expression of alpha-smooth muscle actin, collagen I, and fibronectin can be downgraded by Entrectinib, while E-cadherin can be upregulated. The migration and proliferation of cells were inhibited by Entrectinib. Mechanistically, Entrectinib obstructs TGFβ2/Smad and TGFβ2/non-Smad signaling pathways to hinder the fibrosis cataract by targeting PYK2 protein.

CONCLUSIONS

Targeting with PYK2, Entrectinib can block TGF-β2/Smad and TGF-β2/non-Smad signaling pathways, lessen the activation of EMT, and alleviate fibrosis cataract. Entrectinib may be a potential treatment for fibrosis cataract in clinic.

Single-Cell RNA-Sequencing Identifies Bone Marrow-Derived Progenitor Cells as a Main Source of Extracellular Matrix-Producing Cells Across Multiple Organ-Based Fibrotic Diseases

Fibrosis is characterized by the aberrant deposition of extracellular matrix (ECM) due to dysregulated tissue repair responses, imposing a significant global burden on fibrosis-related diseases. Although alpha-smooth muscle actin (α-SMA/ACTA2)-expressing myofibroblasts are considered as key player in fibrogenesis, the origin of ECM-producing cells remains controversial. To address this issue, we integrated and analyzed large-scale single-cell transcriptomic datasets from patients with distinct fibrotic diseases involving the heart, lung, liver, or kidney. Unexpectedly, not all ACTA2-expressing cells were ECM-producing cells identified by expressing collagen genes; instead, the majority of ECM-producing cells were myofibroblasts and fibroblasts derived from circulating bone marrow precursor, and to a lesser extent from local pericytes and vascular smooth cells in all fibrotic diseases. This was confirmed in sex-mismatched kidney transplants by the discovery that ECM-producing cells originated from recipient, not donor, bone marrow-derived progenitor cells (BMPCs). Moreover, these BMPCs-derived ECM-producing cells exhibited a proinflammatory phenotype. Thus, bone marrow-derived proinflammatory and profibrotic fibroblasts/myofibroblasts with stem cell properties serve as a major source of ECM-producing cells and may play a driving role in tissue fibrosis across a wide range of human fibrotic diseases. Targeting these ECM-producing cells may provide a novel therapy for diseases with fibrosis.

CCDC113 promotes colorectal cancer tumorigenesis and metastasis via TGF-β signaling pathway

Colorectal cancer (CRC) is the second leading cause of cancer-related mortality worldwide. Although CRC patients' survival is improved with surgical resection and immunotherapy, metastasis and recurrence remain major problems leading to poor prognosis. Therefore, exploring pathogenesis and identifying specific biomarkers are crucial for CRC early diagnosis and targeted therapy. CCDC113, a member of CCDC families, has been reported to play roles in ciliary assembly, ciliary activity, PSCI, asthma and early lung cancer diagnosis. However, the functions of CCDC113 in CRC still remain unclear. In this study, we find that CCDC113 is significantly highly expressed in CRC. High expression of CCDC113 is significantly correlated with CRC patients' poor prognosis. CCDC113 is required for CRC tumorigenesis and metastasis. RNA-seq and TCGA database analysis indicate that CCDC113 is positively correlated with TGF-β signaling pathway. TGF-β signaling pathway inhibitor galunisertib could reverse the increased proliferation and migration ability of CRC cells caused by CCDC113 overexpression in vitro and in vivo. These results indicate that CCDC113 promotes CRC tumorigenesis and metastasis via TGF-β signaling pathway. In conclusion, it is the first time to explore the functions and mechanisms of CCDC113 in CRC tumorigenesis and metastasis. And CCDC113 may be a potential biomarker and therapeutic target for CRC intervention.