microRNA-322/424 promotes liver fibrosis by regulating angiogenesis through targeting CUL2/HIF-1α pathway

Fibrosis-Related microRNAs in Crohn's Disease with Fibrostenosis and Inflammatory Stenosis

Crohn's disease (CD) is frequently complicated by strictures that can be either inflammatory or fibrostenotic. This distinction is important for deciding the best treatment course, but it can be difficult to determine clinically, sometimes even by advanced imaging techniques. We performed miRNA PCR panel screening on pooled samples of ileum with CD fibrostenosis or inflammatory stenosis. Eight miRNAs with profibrotic (miR-93-5p, miR-376c-3p and miR-424-5p), or fibroprotective (miR-133a-3p, miR-133b, miR-193a-5p, miR-335-5p and miR-378a-3p) functions described in the literature were selected for validation on 20 samples each of CD with fibrostenosis or inflammatory stenosis, with a separate sampling of the submucosa and subserosa. The results showed significant differences between the groups in subserosal samples, with upregulation of profibrotic miRNAs and downregulation of fibroprotective miRNAs in fibrostenosis compared to inflammatory stenosis. Only miR-424-5p showed a significant difference in the submucosa. There were significant differences in miRNA expression between subserosa and submucosa. Our results provide further evidence that the major differences between fibrostenosis and inflammatory stenosis are located in the subserosa, which is inaccessible to endoscopic sampling, highlighting the need for cross-sectional imaging or serological markers. We identify several miRNAs previously not connected to fibrosis in CD, which could potentially serve as biomarkers of fibrostenosis.

Liver sinusoidal endothelial cell: An important yet often overlooked player in the liver fibrosis

Liver sinusoidal endothelial cells (LSECs) are liver-specific endothelial cells with the highest permeability than other mammalian endothelial cells, characterized by the presence of fenestrae on their surface, the absence of diaphragms and the lack of basement membrane. Located at the interface between blood and other liver cell types, LSECs mediate the exchange of substances between the blood and the Disse space, playing a crucial role in maintaining substance circulation and homeostasis of multicellular communication. As the initial responders to chronic liver injury, the abnormal LSEC activation not only changes their own physicochemical properties but also interrupts their communication with hepatic stellate cells and hepatocytes, which collectively aggravates the process of liver fibrosis. In this review, we have comprehensively updated the various pathways by which LSECs were involved in the initiation and aggravation of liver fibrosis, including but not limited to cellular phenotypic change, the induction of capillarization, decreased permeability and regulation of intercellular communications. Additionally, the intervention effects and latest regulatory mechanisms of anti-fibrotic drugs involved in each aspect have been summarized and discussed systematically. As we studied deeper into unraveling the intricate role of LSECs in the pathophysiology of liver fibrosis, we unveil a promising horizon that pave the way for enhanced patient outcomes.

Comprehensive prognostic and immunological analysis of Cullin2 in pan-cancer and its identification in hepatocellular carcinoma

BACKGROUND

As a member of the Cullin family, Cullin2 (CUL2) is involved in the development and spread of different types of cancers. However, the precise role of CUL2 in human cancer remains largely elusive.

METHODS

In this study, various databases were applied to observe the CUL2 expression. Kaplan-Meier and Spearman correlation analyses were employed to investigate the potential links between CUL2 level, patient prognosis, and the infiltration of immune cells. In addition, the association between CUL2 and the efficacy of immunotherapy in an immunotherapy cohort was investigated. Moreover, the expression and distribution of CUL2 in cells were observed using the Human Protein Atlas (THPA) database. Finally, clinical tissue specimens and in vitro function assays were conducted to validate the expressions and effects of CUL2 on the biological functions in hepatocellular carcinoma (HCC) cells.

RESULTS

While there are variations in CUL2 expression across different organs and cell types, it is notably upregulated in a majority of tumor tissues. In addition, CUL2 gene mutations are common in multiple cancers with low mutation rates and CUL2 is closely related to the prognosis of some cancer's patients, some immune regulatory factors, TMB, MSI, MMR genes, and DNA methylation. Further, our results found that downregulating CUL2 inhibits the proliferation, and migration abilities.

CONCLUSIONS

The expression of CUL2 has an impact on the prognosis of various tumors, and this correlation is particularly noteworthy due to its significant association with the infiltration of immune cells within tumors. CUL2 was an oncogene contributing to the progression of HCC.

Ginsenoside Rg3 promotes hepatic stellate cell ferroptosis by epigenetically regulating ACSL4 to suppress liver fibrosis progression

BACKGROUND

Ginsenoside Rg3 (G-Rg3), extracted from Panax notoginseng, possesses hepatoprotective properties. Hepatic stellate cells (HSCs) activation is responsible for liver fibrosis. Recent studies have reported the suppressive effects of G-Rg3 on HSC activation and proliferation. Ferroptosis is a novel iron regulated cell death. ACSL4, a key indicator of ferroptosis, is commonly methylated in various diseases.

PURPOSE

However, the role of ACSL4 methylation-mediated HSC ferroptosis in G-Rg3 inhibition of hepatic fibrosis needs to be explored.

METHODS

Effects of G-Rg3 on inhibiting fibrosis were evaluated in vivo and in vitro. The impact of G-Rg3 on HSC ferroptosis was assessed in vitro. Furthermore, the expression of ACSL4, ACSL4 methylation and microRNA-6945-3p (miR-6945-3p) levels were determined.

RESULTS

G-Rg3 significantly alleviated CCl4-induced liver fibrosis, accompanied by collagen downregulation. In vitro, G-Rg3 contributed to HSC inactivation, leading to decreased collagen production. G-Rg3 induced HSC ferroptosis, characterized by increased iron accumulation, depletion of glutathione, malondialdehyde levels, and generation of lipid reactive oxygen species. Moreover, G-Rg3 promoted ACSL4 demethylation and restored its expression. Notably, DNMT3B counteracted the effect of G-Rg3-mediated inhibition of ACSL4 methylation and was targeted by miR-6945-3p. Further investigations revealed that G-Rg3 suppressed ACSL4 methylation through miR-6945-3p-mediated DNMT3B inhibition. Consistent with this, miR-6945-3p inhibition reversed G-Rg3-induced ACSL4 expression and HSC ferroptosis.

CONCLUSION

G-Rg3 inhibits ACSL4 methylation by miR-6945-3p-mediated DNMT3B inhibition, thereby promoting HSC ferroptosis and mitigating liver fibrosis.

The role of noncoding RNAs in the tumor microenvironment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the leading fatal malignancy worldwide. The tumor microenvironment (TME) can affect the survival, proliferation, migration, and even dormancy of cancer cells. Hypoxia is an important component of the TME, and hypoxia-inducible factor-1α (HIF-1α) is the most important transcriptional regulator. Noncoding RNAs (ncRNAs), including microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs), comprise a large part of the human transcriptome and play an important role in regulating the tumorigenesis of HCC. This review discusses the role of ncRNAs in hepatocarcinogenesis, epithelial-mesenchymal transition (EMT), and angiogenesis in a hypoxic microenvironment, as well as the interactions between ncRNAs and key components of the TME. It further discusses their use as biomarkers and the potential clinical value of drugs, as well as the challenges faced in the future.

Suppressed Histone H3 Lysine 18 Acetylation Is Involved in Arsenic-Induced Liver Fibrosis in Rats by Triggering the Dedifferentiation of Liver Sinusoidal Endothelial Cells

Arsenic pollution is a global environmental concern. Arsenic-induced chronic liver injury and its irreversible outcomes, including liver cirrhosis and liver cancer, threaten the health of residents in arsenic-contaminated areas. Liver fibrosis is a reversible pathological stage in the progression of arsenic-induced chronic liver injury to cirrhosis and liver cancer. The aim of this study is to identify the epigenetic mechanism of arsenic-induced liver fibrosis based on the dedifferentiation of liver sinusoidal endothelial cells (LSECs). Rats were treated with 0.0, 2.5, 5.0, or 10.0 mg/kg sodium arsenite for 36 weeks. Marked fibrotic phenotypes were observed in the rat livers, manifested by hepatic stellate cell activation and an increased extracellular matrix, as well as the deposition of collagen fibers. The reduced fenestrations on the cells' surface and the increased expression of the dedifferentiation marker CD31 corroborated the LSECs' dedifferentiation in the liver tissue, which was also found to be significantly associated with fibrotic phenotypes. We further revealed that arsenic exposure could inhibit the enrichment of histone H3 lysine 18 acetylation (H3K18ac) in the promoters of Fcgr2b and Lyve1, two key genes responsible for maintaining the differentiation phenotype of LSECs. This inhibition subsequently suppressed the genes' expression, promoting LSEC dedifferentiation and subsequent liver fibrosis. In conclusion, arsenic can trigger liver fibrosis by inhibiting H3K18ac-dependent maintenance of LSEC differentiation. These findings uncover a novel mechanism of arsenic-induced liver fibrosis based on a new insight into epigenetically dependent LSEC dedifferentiation.

Downregulation of miR-20b-5p Contributes to the Progression of Liver Fibrosis via the STAT3 Signaling Pathway In Vivo and In Vitro

BACKGROUND

Activated hepatic stellate cells (HSCs) are primarily involved in liver fibrosis and portal hypertension (PHT). We aimed to investigate the effect of miR-20b-5p on HSCs, liver fibrosis, and PHT.

METHODS

MiR-20b-5p expression in HSCs and in mouse liver fibrosis was determined by qPCR. Further, the effects of miR-20b-5p mimic on HSCs migration, proliferation, and apoptosis were investigated in vitro. A dual-luciferase reporter assay was performed to confirm the direct interaction between miR-20b-5p and STAT3. In vivo, mouse liver fibrosis was established by common bile duct ligation and intervened by agomiR-20b-5p. Sirius red staining and hydroxyproline content were used to evaluate collagen deposition. The α-SMA expression in the liver was detected by IHC and Western blotting. The STAT3 signaling pathway and its downregulated cytokines as well as portal pressure and angiogenesis were explored.

RESULTS

MiR-20b-5p was significantly downregulated during HSCs activation and in mouse liver fibrosis. The functional analyses demonstrated that miR-20b-5p inhibited cell proliferation, activation, and promoted apoptosis in HSCs in vitro. Moreover, miR-20b-5p regulated STAT3 expression by binding to the 3'UTR of its miRNA directly. Overexpression of miR-20b-5p facilitated HSC activation and proliferation by inhibiting the STAT3 signaling pathway. MiR-20b-5p overexpression suppressed the STAT3 and its downstream cytokines and ameliorated liver fibrosis in mice. The intra- and inter-hepatic angiogenesis were also effectively inhibited. The inhibition of liver fibrosis and neoangiogenesis contributed to the decrease of portal pressure.

CONCLUSIONS

MiR-20b-5p plays an important role in the fibrosis and angiogenesis of liver fibrosis by targeting the STAT3 signaling pathway.

Immunometabolism in the tumor microenvironment and its related research progress

The tumor immune microenvironment has been a research hot spot in recent years. The cytokines and metabolites in the microenvironment can promote the occurrence and development of tumor in various ways and help tumor cells get rid of the surveillance of the immune system and complete immune escape. Many studies have shown that the existence of tumor microenvironment is an important reason for the failure of immunotherapy. The impact of the tumor microenvironment on tumor is a systematic study. The current research on this aspect may be only the tip of the iceberg, and a relative lack of integrity, may be related to the heterogeneity of tumor. This review mainly discusses the current status of glucose metabolism and lipid metabolism in the tumor microenvironment, including the phenotype of glucose metabolism and lipid metabolism in the microenvironment; the effects of these metabolic methods and their metabolites on three important immune cells Impact: regulatory T cells (Tregs), tumor-associated macrophages (TAM), natural killer cells (NK cells); and the impact of metabolism in the targeted microenvironment on immunotherapy. At the end of this article,the potential relationship between Ferroptosis and the tumor microenvironment in recent years is also briefly described.

MicroRNA-574-3p Regulates HIF-α Isoforms Promoting Gastric Cancer Epithelial-Mesenchymal Transition via Targeting CUL2

BACKGROUND

Gastric cancer (GC) is the third leading cause of cancer-related deaths worldwide. MicroRNAs (miRNAs) have been widely validated as potential biomarkers for cancer treatment and diagnosis.

AIMS

This paper intends to study the effect and specific mechanism of miR-574-3p/CUL2 axis in GC.

METHODS

The miR-574-3p expression in GC tissues and cell lines was analyzed by reverse transcription polymerase chain reaction (RT-PCR). GC cell (N87) proliferation, migration and invasion were determined by the Brdu assay and Transwell assay, respectively. The tumor xenotransplantation model was established in vivo to test the effect of miR-574-3p or Cullin 2 (CUL2) on tumor growth. The relationship between miR-574-3p and CUL2 was predicated by bioinformatic analysis and verified by dual-luciferase reporter assay and RIP experiment. The expression of CUL2, hypoxia-induced transcription factor-1α (HIF-1α) as well as E-cadherin, Snail and Vimentin was monitored by western blot and immunohistochemistry.

RESULTS

miR-574-3p was overexpressed in GC tissues and cells. Forced upregulation of miR-574-3p enhanced proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) of GC cells (N87), while downregulation of miR-574-3p resulted in reverse effects. Additionally, miR-574-3p promoted N87 cells growth and EMT in vivo. CUL2 was negatively regulated by miR-574-3p in N87 cells, and upregulation of CUL2 repressed the malignant behaviors of N87 cells. Moreover, CUL2 directly interacted with HIF-1α and suppressed HIF-1α expression both in vitro and in vivo.

CONCLUSIONS

miR-574-3p targeted CUL2 to upregulate HIF-1α, thus facilitating the progression of GC.

Integrated Chemical Interpretation and Network Pharmacology Analysis to Reveal the Anti-Liver Fibrosis Effect of Penthorum chinense

Liver fibrosis is a disease with complex pathological mechanisms. Penthorum chinense Pursh (P. chinense) is a traditional Chinese medicine (TCM) for liver injury treatment. However, the pharmacological mechanisms of P. chinense on liver fibrosis have not been investigated and clarified clearly. This study was designed to investigate the chemicals in P. chinense and explore its effect on liver fibrosis. First, we developed a highly efficient method, called DDA-assisted DIA, which can both broaden mass spectrometry (MS) coverage and MS² quality. In DDA-assisted DIA, data-dependent acquisition (DDA) and data-independent acquisition (DIA) were merged to construct a molecular network, in which 1,094 mass features were retained in Penthorum chinense Pursh (P. chinense). Out of these, 169 compounds were identified based on both MS¹ and MS² analysis. After that, based on a network pharmacology study, 94 bioactive compounds and 440 targets of P. chinense associated with liver fibrosis were obtained, forming a tight compound–target network. Meanwhile, the network pharmacology experimental results showed that multiple pathways interacted with the HIF-1 pathway, which was first identified involved in P. chinense. It could be observed that some proteins, such as TNF-α, Timp1, and HO-1, were involved in the HIF-1 pathway. Furthermore, the pharmacological effects of P. chinense on these proteins were verified by CCl₄-induced rat liver fibrosis, and P. chinense was found to improve liver functions through regulating TNF-α, Timp1, and HO-1 expressions. In summary, DDA-assisted DIA could provide more detailed compound information, which will help us to annotate the ingredients of TCM, and combination with computerized network pharmacology provided a theoretical basis for revealing the mechanism of P. chinense.

Effect of miR-183-5p on Cholestatic Liver Fibrosis by Regulating Fork Head Box Protein O1 Expression

Liver fibrosis is a common pathological feature of end-stage liver disease and has no effective treatment. MicroRNAs (miRNAs) have been found to modulate gene expression in liver disease. But the potential role of miRNA in hepatic fibrosis is still unclear. The objective of this research is to study the potential mechanism and biological function of miR-183-5p in liver fibrosis. In this study, we used high-throughput sequencing to find that miR-183-5p is upregulated in human fibrotic liver tissues. In addition, miR-183-5p was upregulated both in rat liver fibrosis tissue induced by bile-duct ligation (BDL) and activated LX-2 cells (human hepatic stellate cell line) according to the result of quantitative real-time PCR (RT-qPCR). Moreover, the inhibition of miR-183-5p alleviated liver fibrosis, decreased the fibrotic biomarker levels in vitro and in vivo, and led toLX-2 cell proliferation inhibition and, apoptosis induction. The result of dual-luciferase assay revealed that miR-183-5p suppressed fork head box protein O1 (FOXO1) expression by binding to its 3'UTR directly. Next, we used lentivirus to overexpress FOXO1 in LX-2 cells, and we found that overexpression of FOXO1 reversed the promotion of miR-183-5p on liver fibrosis, reducing the fibrotic biomarker levels inLX-2 cells, inhibitingLX-2 cell proliferation, and promoting apoptosis. Furthermore, overexpression of FOXO1 prevented the activation of the transforming growth factor (TGF)-β signaling pathway in TGF-β1-induced LX-2 cells according to the result of western blotting. In conclusion, the findings showed thatmiR-183-5p might act as a key regulator of liver fibrosis, and miR-183-5p could promote cholestatic liver fibrosis by inhibiting FOXO1 expression through the TGF-β signaling pathway. Thus, inhibition of miR-183-5pmay be a new way to prevent and improve liver fibrosis.

Epigenetic regulation in fibrosis progress

Fibrosis, a common process of chronic inflammatory diseases, is defined as a repair response disorder when organs undergo continuous damage, ultimately leading to scar formation and functional failure. Around the world, fibrotic diseases cause high mortality, unfortunately, with limited treatment means in clinical practice. With the development and application of deep sequencing technology, comprehensively exploring the epigenetic mechanism in fibrosis has been allowed. Extensive remodeling of epigenetics controlling various cells phenotype and molecular mechanisms involved in fibrogenesis was subsequently verified. In this review, we summarize the regulatory mechanisms of DNA methylation, histone modification, noncoding RNAs (ncRNAs) and N6-methyladenosine (m6A) modification in organ fibrosis, focusing on heart, liver, lung and kidney. Additionally, we emphasize the diversity of epigenetics in the cellular and molecular mechanisms related to fibrosis. Finally, the potential and prospect of targeted therapy for fibrosis based on epigenetic is discussed.

Circ_001209 aggravates diabetic retinal vascular dysfunction through regulating miR-15b-5p/COL12A1

OBJECTIVE

Diabetic retinopathy, a common complication of diabetes mellitus and a major cause of blindness. circRNAs spongs target miRNA and thus influencing mRNA expression in DR. We investigated the mechanism of circ_001209 in regulating diabetic retinal vascular dysfunction.

METHODS

QRT-PCR analysis was performed to detect the expression of miR-15b-5p, COL12A1 and circ_001209 in human retinal vascular endothelial cells (HRVECs) under high glucose conditions. Western blot assay, wound healing assay, transwell assay and tube formation were used to explore the roles of circ_001209/miR-15b-5p/COL12A1 in retinal vascular dysfunction. Bioinformatics analysis and luciferase reporter, RNA-FISH, and overexpression assays were performed to reveal the mechanisms of the circ_001209/miR-15b-5p/COL12A1 interaction. TUNEL staining and H&E staining were used to evaluate the pathological changes in streptozotocin (STZ)-induced DR in rats.

RESULTS

Downregulation of miR-15b-5p under HG conditions promoted proliferation, migration, and tube formation of HRVECs. QRT-PCR and western blot results revealed that miR-15b-5p affected the HRVECs function through targeting COL12A1. Under HG conditions, circ_001209, which acts as a sponge of miR-15b-5p, is upregulated. Besides, overexpression of circ_001209 can affect HRVEC function and aggravate retinal injury in diabetic rats.

CONCLUSION

Upregulation of circ_001209 contributes to vascular dysfunction in diabetic retinas through regulating miR-15b-5p and COL12A1, providing a potential treatment strategy for diabetic retinopathy.

Liver sinusoidal endothelial cells are implicated in multiple fibrotic mechanisms

Chronic liver diseases are attributed to liver injury. Development of fibrosis from chronic liver diseases is a dynamic process that involves multiple molecular and cellular processes. As the first to be impacted by injury, liver sinusoidal endothelial cells (LSECs) are involved in the pathogenesis of liver diseases caused by a variety of etiologies. Moreover, capillarization of LSECs has been recognized as an important event in the development of chronic liver diseases and fibrosis. Studies have reported that various cytokines (such as vascular endothelial growth factor, transforming growth factor-β), and pathways (such as hedgehog, and Notch), as well as epigenetic and metabolic factors are involved in the development of LSEC-mediated liver fibrosis. This review describes the complexity and plasticity of LSECs in fibrotic liver diseases from several perspectives, including the cross-talk between LSECs and other intra-hepatic cells. Moreover, it summarizes the mechanisms of several kinds of LSECs-targeting anti-fibrosis chemicals, and provides a theoretical basis for future studies.