Targeting cIAPs attenuates CCl4-induced liver fibrosis by increasing MMP9 expression derived from neutrophils

Proinflammatory cytokine-induced matrix metalloproteinase-9 expression in temporomandibular joint osteoarthritis is regulated by multiple intracellular mitogen-activated protein kinase pathways

OBJECTIVES

Temporomandibular joint (TMJ) osteoarthritis (OA) is an inflammatory disease that involves periarthritis of the TMJ and destruction of cartilage tissue in the mandibular condyle. However, the role of proinflammatory cytokines in the expression levels of matrix metalloproteinase (MMP) remains inconclusive. Thus, in this study, we aimed to investigate the effect of proinflammatory cytokines on the expression of MMPs.

METHODS

FLS1 cells (mouse TMJ-derived synovial cell line) were treated with tumor necrosis factor alpha (TNF-α) or interleukin (IL)-1β in the presence or absence of mitogen-activated protein kinase (MAPK) inhibitors. The mRNA expression levels of MMP-2 and MMP-9 were examined by reverse transcription-quantitative polymerase chain reaction. Additionally, the phosphorylation status of extracellular signal-regulated kinase (ERK)1/2 and p38 MAPK in the FLS1 cells treated with TNF-α or IL-1β was evaluated by performing western blotting analysis.

RESULTS

TNF-α and IL-1β significantly increased the expression of MMP-9 in the FLS1 cells; however, MMP-2 expression remained unaffected. Mitogen-activated protein kinase kinase (MEK) and p38 MAPK inhibitors significantly suppressed cytokine-induced MMP-9 upregulation. Conversely, Jun amino-terminal kinase (JNK) inhibitors further increased MMP-9 expression in the cells treated with TNF-α or IL-1β. Moreover, TNF-α and IL-1β enhanced ERK1/2 and p38 MAPK phosphorylation in the FLS1 cells.

CONCLUSIONS

TNF-α and IL-1β induced MMP-9 expression in the FLS1 cells via the MEK/ERK and p38 MAPK pathways and suppressed it via the JNK pathway. Thus, proinflammatory cytokines control MMP-9 expression in TMJ-OA by regulating multiple MAPK pathways.

Artemisitene ameliorates carbon tetrachloride-induced liver fibrosis by inhibiting NLRP3 inflammasome activation and modulating immune responses

Artemisitene (ATT), an artemisinin (ART) analog retaining the endoperoxide moiety and incorporating an additional α, β-unsaturated carbonyl structure, exhibits enhanced biological activities. However, its therapeutic effects on liver fibrosis remain unclear. In this study, we demonstrated that ATT significantly alleviated liver inflammation and fibrosis induced by carbon tetrachloride (CCL4) in mice. ATT treatment markedly reduced the count of neutrophils in the liver, as well as macrophages in both the liver and spleen. Additionally, the frequencies of Th2 and Th17 cells were significantly lowered, while Th1 cells frequency and the Th1/Th2 index were notably increased. The frequency of ILC2 cells, correlated with ST2 and IL-33 expression levels, was also significantly lowered. Consistently, ATT inhibited NLRP3 inflammasome activation, which was positively associated with AST and ALT levels, and with the count of Neutrophils, macrophages, and ILC2 cells, but negatively correlated with Th1frequeny. Furthermore, liver fibrosis severity showed a significant positive correlation with neutrophil and Th17 cell counts in the liver, and a negative correlation with Th1 cell count and the Th1/Th2 index. Therefore, ATT alleviated CCL4-induced mice liver fibrosis through NLRP3 inflammasome inhibition and immunomodulation.

Mendelian randomization analysis of the causal relationship between immune cells and keloid

Immune cells play complex roles in the formation of keloid. We aimed to investigate the causal relationship between immune cells and keloid and provide genetic evidence for the association between immune cells and keloid risk. Based on data from a genome-wide association study (GWAS), we performed a comprehensive two-sample Mendelian randomization (MR) analysis of 731 immune cell traits in 481,912 keloid cases. We used the inverse-variance weighting (IVW) method as the primary analysis. Then, a comprehensive sensitivity analysis was adopted to verify the results' robustness, heterogeneity, and horizontal pleiotropy. Finally, reverse MR analysis was performed. The IVW method in forward MR analysis showed that CD66b++ myeloid cell AC was negatively associated with keloid risk (OR<1, p<0.05). Consistently, reverse MR analysis showed that keloid risk was negatively associated with CD66b++ myeloid cell AC (OR=0.85, p=0.012). No significant horizontal pleiotropy or heterogeneity was observed. The results of MR analysis demonstrate a bidirectional causal association between CD66b++ myeloid cell AC and keloid formation, suggesting that CD66b++ myeloid cell AC is a protective factor against keloid.

Pathogenesis and interaction of neutrophils and extracellular vesicles in noncancer liver diseases

Liver disease ranks as the eleventh leading cause of mortality, leading to approximately 2 million deaths annually worldwide. Neutrophils are a type of immune cell that are abundant in peripheral blood and play a vital role in innate immunity by quickly reaching the site of liver injury. They exert their influence on liver diseases through autocrine, paracrine, and immunomodulatory mechanisms. Extracellular vesicles, phospholipid bilayer vesicles, transport a variety of substances, such as proteins, nucleic acids, lipids, and pathogenic factors, for intercellular communication. They regulate cell communication and perform their functions by delivering biological information. Current research has revealed the involvement of the interaction between neutrophils and extracellular vesicles in the pathogenesis of liver disease. Moreover, more research has focused on targeting neutrophils as a therapeutic strategy to attenuate disease progression. Therefore, this article summarizes the roles of neutrophils, extracellular vesicles, and their interactions in noncancerous liver diseases.

Targeting MMP9 in CTNNB1 mutant hepatocellular carcinoma restores CD8+ T cell-mediated antitumour immunity and improves anti-PD-1 efficacy

OBJECTIVE

The gain of function (GOF) CTNNB1 mutations (CTNNB1 GOF ) in hepatocellular carcinoma (HCC) cause significant immune escape and resistance to anti-PD-1. Here, we aimed to investigate the mechanism of CTNNB1 GOF HCC-mediated immune escape and raise a new therapeutic strategy to enhance anti-PD-1 efficacy in HCC.

DESIGN

RNA sequencing was performed to identify the key downstream genes of CTNNB1 GOF associated with immune escape. An in vitro coculture system, murine subcutaneous or orthotopic models, spontaneously tumourigenic models in conditional gene-knock-out mice and flow cytometry were used to explore the biological function of matrix metallopeptidase 9 (MMP9) in tumour progression and immune escape. Single-cell RNA sequencing and proteomics were used to gain insight into the underlying mechanisms of MMP9.

RESULTS

MMP9 was significantly upregulated in CTNNB1 GOF HCC. MMP9 suppressed infiltration and cytotoxicity of CD8+ T cells, which was critical for CTNNB1 GOF to drive the suppressive tumour immune microenvironment (TIME) and anti-PD-1 resistance. Mechanistically, CTNNB1 GOF downregulated sirtuin 2 (SIRT2), resulting in promotion of β-catenin/lysine demethylase 4D (KDM4D) complex formation that fostered the transcriptional activation of MMP9. The secretion of MMP9 from HCC mediated slingshot protein phosphatase 1 (SSH1) shedding from CD8+ T cells, leading to the inhibition of C-X-C motif chemokine receptor 3 (CXCR3)-mediated intracellular of G protein-coupled receptors signalling. Additionally, MMP9 blockade remodelled the TIME and potentiated the sensitivity of anti-PD-1 therapy in HCC.

CONCLUSIONS

CTNNB1 GOF induces a suppressive TIME by activating secretion of MMP9. Targeting MMP9 reshapes TIME and potentiates anti-PD-1 efficacy in CTNNB1 GOF HCC.

The role of matrix metalloproteinase 9 in fibrosis diseases and its molecular mechanisms

Fibrosis is a process of tissue repair that results in the slow creation of scar tissue to replace healthy tissue and can affect any tissue or organ. Its primary feature is the massive deposition of extracellular matrix (mainly collagen), eventually leading to tissue dysfunction and organ failure. The progression of fibrotic diseases has put a significant strain on global health and the economy, and as a result, there is an urgent need to find some new therapies. Previous studies have identified that inflammation, oxidative stress, some cytokines, and remodeling play a crucial role in fibrotic diseases and are essential avenues for treating fibrotic diseases. Among them, matrix metalloproteinases (MMPs) are considered the main targets for the treatment of fibrotic diseases since they are the primary driver involved in ECM degradation, and tissue inhibitors of metalloproteinases (TIMPs) are natural endogenous inhibitors of MMPs. Through previous studies, we found that MMP-9 is an essential target for treating fibrotic diseases. However, it is worth noting that MMP-9 plays a bidirectional regulatory role in different fibrotic diseases or different stages of the same fibrotic disease. Previously identified MMP-9 inhibitors, such as pirfenidone and nintedanib, suffer from some rather pronounced side effects, and therefore, there is an urgent need to investigate new drugs. In this review, we explore the mechanism of action and signaling pathways of MMP-9 in different tissues and organs, hoping to provide some ideas for developing safer and more effective biologics.

Comprehensive analysis of an endoplasmic reticulum stress-related gene prediction model and immune infiltration in idiopathic pulmonary fibrosis

Background

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive interstitial lung disease. This study aimed to investigate the involvement of endoplasmic reticulum stress (ERS) in IPF and explore its correlation with immune infiltration.

Methods

ERS-related differentially expressed genes (ERSRDEGs) were identified by intersecting differentially expressed genes (DEGs) from three Gene Expression Omnibus datasets with ERS-related gene sets. Gene Set Variation Analysis and Gene Ontology were used to explore the potential biological mechanisms underlying ERS. A nomogram was developed using the risk signature derived from the ERSRDEGs to perform risk assessment. The diagnostic value of the risk signature was evaluated using receiver operating characteristics, calibration, and decision curve analyses. The ERS score of patients with IPF was measured using a single-sample Gene Set Enrichment Analysis (ssGSEA) algorithm. Subsequently, a prognostic model based on the ERS scores was established. The proportion of immune cell infiltration was assessed using the ssGSEA and CIBERSORT algorithms. Finally, the expression of ERSRDEGs was validated in vivo and in vitro via RT-qPCR.

Results

This study developed an 8-ERSRDEGs signature. Based on the expression of these genes, we constructed a diagnostic nomogram model in which agouti-related neuropeptide had a significantly greater impact on the model. The area under the curve values for the predictive value of the ERSRDEGs signature were 0.975 and 1.000 for GSE70866 and GSE110147, respectively. We developed a prognostic model based on the ERS scores of patients with IPF. Furthermore, we classified patients with IPF into two subtypes based on their signatures. The RT-qPCR validation results supported the reliability of most of our conclusions.

Conclusion

We developed and verified a risk model using eight ERSRDEGs. These eight genes can potentially affect the progression of IPF by regulating ERS and immune responses.

Transcriptome and proteomics conjoint analysis reveal anti-alcoholic liver injury effect of Dianhong Black Tea volatile substances

Dianhong Black Tea, a fermented tea containing various bioactive ingredients, has been found to have a significant role in alleviating alcoholic liver injury (ALI). One of its main unique components, Dianhong Black Tea volatile substances (DBTVS), may have potential anti-ALI effects. However, its effects and underlying molecular mechanisms are still unknown. In this study, we aimed to investigate the potential of DBTVS as an anti-ALI agent using alcohol-fed rats. We assessed the effect of DBTVS on ALI by analyzing serum transaminase and lipid levels, as well as conducting hematoxylin-eosin and oil red O staining. Additionally, GC-MS was used to detect the components of DBTVS, while transcriptome, proteomics analysis, Western blot, and molecular docking were employed to uncover the underlying mechanisms. Our results demonstrated that DBTVS significantly reduced serum ALT and AST levels and improved lipid metabolism disorders. Moreover, we identified 14 components in DBTVS, with five of them exhibiting strong binding affinity with key proteins. These findings suggested that DBTVS could be a promising agent for the prevention and treatment of ALI. Its potential therapeutic effects may be attributed to its ability to regulate lipid metabolism through the PPAR signaling pathway.

Glutathione Might Attenuate Arsenic-Induced Liver Injury by Modulating the Foxa2-XIAP Axis to Reduce Oxidative Stress and Mitochondrial Apoptosis

Arsenic (AS) is a metalloid element that widely exists and can cause different degrees of liver damage. The molecular mechanism of arsenic-induced liver injury has yet to be fully elucidated. Clinically, glutathione (GSH) is often used as an antidote for heavy metal poisoning and hepatoprotective drugs. However, the hepatoprotective effect of glutathione remains unknown in arsenic-induced liver injury. The regulatory relationship between Foxa2 and XIAP may play an important role in mitochondrial survival and death. Therefore, we took Foxa2-XIAP as the axis to explore the protective mechanism of GSH. In this study, we first established a mouse model of chronic arsenic exposure and examined liver function as reflected by quantitative parameters such as aspartate aminotransferase and alanine aminotransferase. Also, redox parameters in the liver were measured, including malondialdehyde, superoxide dismutase, 8-hydroxy-2'-deoxyguanosin, and glutathione peroxidase. RT-qPCR and western-blotting were used to detect the levels of related genes and proteins, such as Foxa2, XIAP, Smac, Bax, Bcl2, Caspase9, and Caspase3. Subsequently, GSH was administered at the same time as high arsenic exposure, and changes in the above parameters were observed. After a comprehensive analysis of the above results, we demonstrate that GSH treatment alleviates arsenic-induced oxidative stress and inhibits the mitochondrial pathway of apoptosis, which can be regulated through the Foxa2 and XIAP axis. The present study would be helpful in elucidating the molecular mechanism of arsenic-induced liver injury and identifying a new potential therapeutic target. And we also provided new theoretical support for glutathione in the treatment of liver damage caused by arsenic.

Hepatoprotective Efficacy of Cycloastragenol Alleviated the Progression of Liver Fibrosis in Carbon-Tetrachloride-Treated Mice

The continuous death of hepatocytes induced by various etiologies leads to an aberrant tissue healing process and promotes the progression of liver fibrosis and ultimately chronic liver diseases. To date, effective treatments to delay this harmful process remain an unmet clinical need. Cycloastragenol is an active phytochemical substance isolated from Astragalus membranaceus, a plant used in traditional Chinese medicine to protect the liver. Therefore, our study aimed to elucidate the efficacy of cycloastragenol on carbon-tetrachloride (CCl₄)-induced liver fibrosis in mice. We found that cycloastragenol at 200 mg/kg dosage exhibited anti-fibrotic efficacy as demonstrated by a decrease in collagen deposition, downregulation of mRNA expression of collagen type 1, and a reduction in the content of total collagens. In addition, cycloastragenol further augmented the levels of anti-fibrotic matrix metalloproteinases (Mmps), that is, Mmp8, proMmp9, and Mmp12, which play a pivotal role in fibrosis resolution. According to histological analysis and serum markers of hepatotoxicity, cycloastragenol protected the livers from damage and mitigated the increment of serum alanine aminotransferase and bilirubin implicating hepatoprotective efficacy against CCl₄. Moreover, cycloastragenol upregulated the mRNA expression of interleukin 6, a pleiotropic cytokine plays a vital role in the promotion of hepatocyte regeneration. In conclusion, cycloastragenol alleviated the progression of liver fibrosis in CCl₄-treated mice and its anti-fibrotic efficacy was mainly due to the hepatoprotective efficacy.

A, Venkidasamy B, Cespedes-Acuna CL, Nile SH, Yan G, Zheng H. Pien-Tze-Huang alleviates CCl4-induced liver fibrosis through the inhibition of HSC autophagy and the TGF-β1/Smad2 pathway

Ethnopharmacological relevance: Pien-Tze-Huang (PZH)—a traditional Chinese medicine (TCM) compound—has been employed to treat various liver inflammation and tumors for over 10 decades. Interestingly, most of the pharmacological effects had been validated and explored toward liver ailment along with pro-inflammatory conditions and cancer at the cellular and molecular level to date.

Aim of the study: The present study aimed to investigate the therapeutic effect of PZH on autophagy and TGF-β1 signaling pathways in rats with liver fibrosis and hepatic stellate cell line (HSC).

Materials and methods: Male SD rats with carbon tetrachloride (CCl4)-induced liver fibrosis were used as the animal model. Next, PZH treatment was given for 8 weeks. Afterward, the therapeutic effects of PZH were analyzed through a hepatic tissue structure by hematoxylin-eosin (H&E), Van Gieson (VG) staining, and transmission electron microscopy (TEM), activity of ALT and AST by enzyme-associated immunosorbent assay as well. Subsequently, mRNA and protein expression were examined by quantitative polymerase chain reaction (qPCR), Western blotting, and immunohistochemistry (IHC). Then, the cell vitality of PZH-treated HSC and the expression of key molecules prevailing to autophagy were studied in vitro. Meanwhile, SM16 (a novel small molecular inhibitor which inhibits TGFβ-induced Smad2 phosphorylation) was employed to confirm PZH’s effects on the proliferation and autophagy of HSC.

Results: PZH pharmacologically exerted anti-hepatic fibrosis effects as demonstrated by protecting hepatocytes and improving hepatic function. The results revealed the reduced production of extracellular collagen by adjusting the balance of matrix metalloproteinase (MMP) 2, MMP9, and tissue inhibitor of matrix metalloproteinase 1 (TIMP1) in PZH-treated CCl4-induced liver fibrosis. Interestingly, PZH inhibited the activation of HSC by down-regulating TGF-β1 and phosphorylating Smad2. Furthermore, PZH down-regulated yeast Atg6 (Beclin-1) and microtubule-associated protein light chain 3 (LC3) toward suppressing HSC autophagy, and PZH exhibited similar effects to that of SM16.

Conclusion: To conclude, PZH alleviated CCl4-induced liver fibrosis to reduce the production of extracellular collagen and inhibiting the activation of HSC. In addition, their pharmacological mechanisms related to autophagy and TGF-β1/Smad2 signaling pathways were revealed for the first time.

LINC01605 knockdown induces apoptosis in human Tenon's capsule fibroblasts by inhibiting autophagy

Glaucoma is an irreversible disease that causes blindness. Formation of a hypertrophic scar (HS) is the main cause of failure of glaucoma surgery. The long non-coding RNA LINC01605 is closely associated with the formation of HS; however, the function of LINC01605 in the formation and development of HS remains unclear. For this study, firstly, human Tenon's capsule fibroblasts (HTFs) and corneal epithelial cells (control cells) were collected from patients (n=5) with POAG who underwent glaucoma filtration surgery at Fuyang People's Hospital. Immunofluorescence analysis was performed to detect the expression levels of vimentin (one of the main components of medium fiber and plays an important role in the cytoskeleton and motility), keratin (the main component of cytoskeletal proteins) and LC3 (an autophagy marker). In addition, reverse transcription-quantitative PCR analysis was performed to detect LINC01605 expression. Besides, the Cell Counting Kit-8 assay was performed to assess the viability of human Tenon's capsule fibroblasts (HTFs). Next, flow cytometry was performed to detect HTF apoptosis. Furthermore, western blot analysis was performed for Bax, Bcl-2, Pro-caspase-3, cleaved caspase-3, phosphorylated (p-)Smad2, Smad2, α-SMA, MMP9, ATG7, p62, beclin 1, p-AMPK and AMPK in HTFs to determine the mechanism by which LINC01605 regulates the formation and development of HS. Moreover, a Transwell assay was performed to detect the migratory ability of HTFs. The results demonstrated that LINC01605 was significantly upregulated in HS tissues compared with that in normal (control/healthy) tissues. In addition, vimentin was highly expressed in HTFs, whereas keratin was expressed at a low level. Also, in HTFs, LINC01605 knockdown inhibited cell viability by inducing apoptosis, decreasing Smad2 activation and inhibiting autophagy. Furthermore, LINC01605 knockdown significantly inhibited the migratory ability of HTFs. Transfection with LINC01605 small interference RNAs significantly downregulated the expression levels of p-Smad2, α-SMA and MMP9 in HTFs. Furthermore, LINC01605 knockdown notably inhibited the viability and migration, and induced the apoptosis of HTFs, the effects of which were reversed following treatment with TGF-β. Taken together, the results of the present study suggested that LINC01605 knockdown may inhibit the viability of HTFs by inducing the apoptotic pathway. These findings may provide novel directions for the treatment of HS.