Procollagen-lysine 2-oxoglutarate 5-dioxygenase 2 promotes collagen cross-linking and ECM stiffening to induce liver fibrosis.

Procollagen-lysine 2-oxoglutarate 5-dioxygenase 2 (Plod2) is a key collagen lysyl hydroxylase mediating the formation of collagen fiber and stabilized collagen cross-links, and has been identified in several forms of fibrosis. However, the potential role and regulatory mechanism of Plod2 in liver fibrosis remain unclear yet. Mouse liver fibrosis models were induced by injecting carbon tetrachloride (CCl4) intraperitoneally. The morphology and alignment of collagen was observed under transmission and scanning electron microscopy, and extracellular matrix (ECM) stiffness was measured by atomic force microscopy. Large amounts of densely packed fibrillar collagen fibers produced by myofibroblasts (MFs) were deposited in fibrotic liver of mice reaching very large diameters in the cross section, accompanied with ECM stiffening, which was positively correlated with collagen-crosslinking. The expression of Plod2 was dynamically up-regulated in fibrotic liver of mouse and human. In MFs transfection of Plod2 siRNA made collagen fibers more orderly and linear aligned which can be easily degraded and protected from ECM stiffness. Administration of Plod2 siRNA preventatively or therapeutically in CCl4 mice reduced the average size of collagen bundles in transverse section, increased collagen solubility, decreases the levels of crosslinking products hydroxylysylpyridinoline and lysylpyridinoline, prevented ECM stiffening and alleviated liver fibrosis. Altogether, Plod2 mediates the formation of stabilized profibrotic collagen cross-links in MFs, leading to the alteration of collagen solubility and ECM stiffness, and eventually aggravates liver fibrosis, which provide potential target for the treatment of liver disease.

Development of a new Cox model for predicting long-term survival in hepatitis cirrhosis patients underwent transjugular intrahepatic portosystemic shunts.

BACKGROUND: Transjugular intrahepatic portosystemic shunt (TIPS) placement is a procedure that can effectively treat complications of portal hypertension, such as variceal bleeding and refractory ascites. However, there have been no specific studies on predicting long-term survival after TIPS placement. AIM: To establish a model to predict long-term survival in patients with hepatitis cirrhosis after TIPS. METHODS: A retrospective analysis was conducted on a cohort of 224 patients who underwent TIPS implantation. Through univariate and multivariate Cox regression analyses, various factors were examined for their ability to predict survival at 6 years after TIPS. Consequently, a composite score was formulated, encompassing the indication, shunt reasonability, portal venous pressure gradient (PPG) after TIPS, percentage decrease in portal venous pressure (PVP), indocyanine green retention rate at 15 min (ICGR15) and total bilirubin (Tbil) level. Furthermore, the performance of the newly developed Cox (NDC) model was evaluated in an internal validation cohort and compared with that of a series of existing models. RESULTS: The indication (variceal bleeding or ascites), shunt reasonability (reasonable or unreasonable), ICGR15, postoperative PPG, percentage of PVP decrease and Tbil were found to be independent factors affecting long-term survival after TIPS placement. The NDC model incorporated these parameters and successfully identified patients at high risk, exhibiting a notably elevated mortality rate following the TIPS procedure, as observed in both the training and validation cohorts. Additionally, in terms of predicting the long-term survival rate, the performance of the NDC model was significantly better than that of the other four models [Child-Pugh, model for end-stage liver disease (MELD), MELD-sodium and the Freiburg index of post-TIPS survival]. CONCLUSION: The NDC model can accurately predict long-term survival after the TIPS procedure in patients with hepatitis cirrhosis, help identify high-risk patients and guide follow-up management after TIPS implantation.

A novel nomogram predicting overt hepatic encephalopathy after transjugular intrahepatic portosystemic shunt in portal hypertension patients.

We aim to develop a nomogram to predict overt hepatic encephalopathy (OHE) after transjugular intrahepatic portosystemic shunt (TIPS) in patients with portal hypertension, according to demographic/clinical indicators such as age, creatinine, blood ammonia, indocyanine green retention rate at 15 min (ICG-R15) and percentage of Portal pressure gradient (PPG) decline. In this retrospective study, 296 patients with portal hypertension who received elective TIPS in Beijing Shijitan Hospital from June 2018 to June 2020 were included. These patients were randomly divided into a training cohort (n = 207) and a validation cohort (n = 89). According to the occurrence of OHE, patients were assigned to OHE group and non-OHE group. Both univariate and multivariate analyses were performed to determine independent variables for predicting OHE after TIPS. Accordingly, receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA) were used to compare the accuracy and superiority of a novel model with conventional Child-Pugh and MELD scoring model. Age (OR 1.036, 95% CI 1.002-1.070, p = 0.037), Creatinine (OR 1.011, 95% CI 1.003-1.019, p = 0.009), Blood ammonia (OR 1.025, 95% CI 1.006-1.044, p = 0.011), ICG-R15 (OR 1.030, 95% CI 1.009-1.052, p = 0.004) and Percentage decline in PPG (OR 1.068, 95% CI 1.029-1.109, p = 0.001) were independent risk factors for OHE after TIPS using multifactorial analysis. A nomogram was constructed using a well-fit calibration curve for each of these five covariates. When compared to Child-Pugh and MELD score, this new nomogram has a better predictive value (C-index = 0.828, 95% CI 0.761-0.896). Consistently, this finding was reproduceable in validation cohort and confirmed with DCA. A unique nomogram was developed to predict OHE after TIPS in patients with PHT, with a high prediction sensitivity and specificity performance than commonly applied scoring systems.

Correlation between hepatic venous pressure gradient and portal pressure gradient in patients with autoimmune cirrhotic portal hypertension and collateral branches of the hepatic vein.

AIM: To assess the correlation and agreement between hepatic venous pressure gradient (HVPG) and portal pressure gradient (PPG) in patients with autoimmune liver diseases (ALD) and portal hypertension, and to investigate the extent to which hepatic vein collateralization affects the accuracy of this assessment. METHODS: Ninety-eight patients with ALD between 2017 and 2021 who underwent transjugular intrahepatic portosystemic shunt with conventional and innovative 15 mL pressurized contrast were selected to measure wedged hepatic venous pressure (WHVP) and portal venous pressure and to calculate the HVPG and PPG. Pearson's correlation was used for correlation analysis between the two groups. Bland-Altman plots were plotted to estimate the agreement between paired pressures. RESULTS: The r values of PPG and HVPG in the early, middle, late, and portal venous visualization were 0.404, 0.789, 0.807, and 0.830, respectively, and the R2 values were 0.163, 0.622, 0.651, and 0.690, respectively. The p value for the r and R2 values in the early group was 0.015, and the p values in the remaining groups were less than 0.001. Bland-Altman plots showed that patients in the portal venous visualization group had the narrowest 95% limits of agreement. The mean value of the difference was close to the zero-scale line. CONCLUSIONS: In patients with ALD, the correlation between the HVPG and PPG was good, and the later the collateral development, the better the correlation. Hepatic vein collateral was an essential factor in underestimating WHVP and HVPG, and the earlier the collateral appeared, the more obvious the underestimation.

Neuron-Glial Antigen 2 Participates in Liver Fibrosis via Regulating the Differentiation of Bone Marrow Mesenchymal Stem Cell to Myofibroblast.

Neuron-glial antigen 2 (NG2, gene name: Cspg4) has been characterized as an important factor in many diseases. However, the pathophysiological relevance of NG2 in liver disease specifically regarding bone marrow mesenchymal stem cell (BMSC) differentiation to myofibroblast (MF) and the molecular details remain unknown. Human liver tissues were obtained from patients with different chronic liver diseases, and mouse liver injury models were induced by feeding a methionine-choline-deficient and high-fat diet, carbon tetrachloride administration, or bile duct ligation operation. NG2 expression was increased in human and mouse fibrotic liver and positively correlated with MF markers α-smooth muscle actin (αSMA) and other fibrotic markers in the liver. There was a co-localization between NG2 and αSMA, NG2 and EGFP (BMSC-derived MF) in the fibrotic liver determined by immunofluorescence analysis. In vitro, TGFß1-treated BMSC showed a progressive increase in NG2 levels, which were mainly expressed on the membrane surface. Interestingly, there was a translocation of NG2 from the cell membrane into cytoplasm after the transfection of Cspg4 siRNA in TGFß1-treated BMSC. siRNA-mediated inhibition of Cspg4 abrogated the TGFß1-induced BMSC differentiation to MF. Importantly, inhibition of NG2 in vivo significantly attenuated the extent of liver fibrosis in methionine-choline-deficient and high fat (MCDHF) mice, as demonstrated by the decreased mRNA expression of fibrotic parameters, collagen deposition, serum transaminase levels, liver steatosis and inflammation after the administration of Cspg4 siRNA in MCDHF mice. We identify the positive regulation of NG2 in BMSC differentiation to MF during liver fibrosis, which may provide a promising target for the treatment of liver disease.

Circ_0007534 as new emerging target in cancer: Biological functions and molecular interactions.

Circular RNA (circRNAs), an important member of the non-coding RNA (ncRNA) family, are widely expressed in a variety of biological cells. Owing to their stable structures, sequence conservations, and cell- or tissue-specific expressions, these RNA have become a popular subject of scientific research. With the development of sequencing methods, it has been revealed that circRNAs exert their biological function by sponging microRNAs (miRNAs), regulating transcription, or binding to proteins. Humans have historically been significantly impacted by various types of cancer. Studies have shown that circRNAs are abnormally expressed in various cancers and are involved in the occurrence and development of malignant tumors, such as tumor cell proliferation, migration, and invasion. As one of its star molecules, circ_0007534 is upregulated in colorectal, cervical, and pancreatic cancers; is closely related to the occurrence, development, and prognosis of tumors; and is expected to become a novel tumor marker and therapeutic target. This article briefly reviews the expression and mechanism of circ_0007534 in malignant tumors based on the domestic and foreign literature.

Correlation of pressure gradient in three hepatic veins with portal pressure gradient.

BACKGROUND: The liver is one of the most important organs in the human body, with functions such as detoxification, digestion, and blood coagulation. In terms of vascular anatomy, the liver is divided into the left and the right liver by the main portal vein, and there are three hepatic efferent veins (right, middle, and left) and two portal branches. Patients with impaired liver function have increased intrahepatic vascular resistance and splanchnic vasodilation, which may lead to an increase in the portal pressure gradient (PPG) and cause portal hypertension (PHT). In order to measure the increased pressure gradient of portal vein, the hepatic venous pressure gradient (HVPG) can be measured to reflect it in clinical practice. The accuracy of PPG measurements is directly related to patient prognosis. AIM: To analyze the correlation between HVPG of three hepatic veins and PPG in patients with PHT. METHODS: From January 2017 to December 2019, 102 patients with PHT who met the inclusion criteria were evaluated during the transjugular intrahepatic portosystemic shunt procedure and analyzed. RESULTS: The mean HVPG of the middle hepatic vein was 17.47 ± 10.25 mmHg, and the mean HVPG of the right and left hepatic veins was 16.34 ± 7.60 and 16.52 ± 8.15 mmHg, respectively. The average PPG was 26.03 ± 9.24 mmHg. The correlation coefficient and coefficient of determination of the right hepatic vein, middle hepatic vein, and left hepatic vein were 0.15 and 0.02 (P = 0.164); 0.25 and 0.05 (P = 0.013); and 0.14 and 0.02 (P = 0.013), respectively. The mean wedged hepatic vein/venous pressure (WHVP) of the middle and left hepatic veins was similar at 29.71 ± 12.48 and 29.1 ± 10.91 mmHg, respectively, and the mean WHVP of the right hepatic vein was slightly lower at 28.01 ± 8.95 mmHg. The mean portal vein pressure was 34.11 ± 8.56 mmHg. The correlation coefficient and coefficient of determination of the right hepatic vein, middle hepatic vein, and left hepatic vein were 0.26 and 0.07 (P = 0.009); 0.38 and 0.15 (P < 0.001); and 0.26 and 0.07 (P = 0.008), respectively. The average free hepatic venous pressure (FHVP) of the right hepatic vein was lowest at 11.67 ± 5.34 mmHg, and the average FHVP of the middle and left hepatic veins was slightly higher at 12.19 ± 4.88 and 11.67 ± 5.34 mmHg, respectively. The average inferior vena cava pressure was 8.27 ± 4.04 mmHg. The correlation coefficient and coefficient of determination of the right hepatic vein, middle hepatic vein, and left hepatic vein were 0.30 and 0.09 (P = 0.002); 0.18 and 0.03 (P = 0.078); and 0.16 and 0.03 (P = 0.111), respectively. CONCLUSION: Measurement of the middle hepatic vein HVPG could better represent PPG. Considering the high success rate of clinical measurement of the right hepatic vein, it can be the second choice.

Dual Targeting of Angipoietin-1 and von Willebrand Factor by microRNA-671-5p Attenuates Liver Angiogenesis and Fibrosis.

Angipoietin-1 (Angpt1) and von Willebrand factor (VWF) are two important angiogenic molecules that can drive pathologic angiogenesis and progression of liver fibrosis in our previous study. MicroRNAs (miRs) participate in a variety of physiological and pathological processes, including angiogenesis. However, the critical miRs targeting Angpt1 or VWF and potential molecular mechanism underlying liver fibrosis-associated angiogenesis is not clear yet. Human liver tissues were obtained from patients with different chronic liver diseases. Mouse models of liver fibrosis were induced by injection of CCl4 or bile duct ligation (BDL) operation. MiR-671-5p was predicted to target Angpt1 and VWF from three databases (miRanda, RNA22v2, and miRwalk). MiR-671-5p expression was decreased in the fibrotic liver of human and mice, with a negative correlation with the levels of Angpt1, VWF, sphingosine kinase-1 (SphK1, the rate-limiting enzyme for sphingosine 1-phosphate [S1P] formation), transforming growth factor ß1 (TGFß1), hypoxia inducible factor (Hif)1α, Hif2α, and fibrosis markers. Importantly, miR-671-5p expression was down-regulated in fluorescence-activated cell sorted liver sinusoidal endothelial cells and hepatic stellate cells (HSCs) in CCl4 mice compared with control mice. In vitro miR-671-5p expression was also decreased in S1P-stimulated HSCs and TGFß1-activated liver sinusoidal endothelial cells, negatively correlated with Angpt1 and VWF expression. MiR-671-5p directly targeted Angpt1 and VWF by luciferase reporter assays. In vivo administration of miR-671-5p agomir decreased the messenger RNA and protein levels of Anpgt1 and VWF, and attenuated CCl4 -induced or BDL-induced liver angiogenesis and fibrosis. Conclusion: We identify the negative regulation of miR-671-5p on Angpt1 and VWF and liver fibrosis-associated angiogenesis, which may provide promising targets for the prevention and treatment of liver disease.

Silencing IQGAP1 alleviates hepatic fibrogenesis via blocking bone marrow mesenchymal stromal cell recruitment to fibrotic liver.

IQ motif-containing guanosine triphosphatase (GTPase)-activating protein 1 (IQGAP1) is a cytosolic scaffolding protein involved in cell migration. Our previous studies suggest sphingosine 1-phosphate (S1P) triggers bone marrow (BM) mesenchymal stromal cells (BMSCs) to damaged liver, thereby promoting liver fibrosis. However, the role of IQGAP1 in S1P-induced BMSC migration and liver fibrogenesis remains unclear. Chimeric mice of BM cell labeled by EGFP were used to build methionine-choline-deficient and high-fat (MCDHF)-diet-induced mouse liver fibrosis. IQGAP1 small interfering RNA (siRNA) was utilized to silence IQGAP1 in vivo. IQGAP1 expression is significantly elevated in MCDHF-diet-induced mouse fibrotic livers. Positive correlations are presented between IQGAP1 and fibrosis hallmarks expressions in human and mouse fibrotic livers. In vitro, depressing IQGAP1 expression blocks S1P-induced motility and cytoskeleton remodeling of BMSCs. S1P facilitates IQGAP1 aggregating to plasma membrane via S1P receptor 3 (S1PR3) and Cdc42/Rac1. In addition, IQGAP1 binds to Cdc42/Rac1, regulating S1P-induced activation of Cdc42/Rac1 and mediating BMSC migration in concert. In vivo, silencing IQGAP1 reduces the recruitment of BMSCs to impaired liver and effectively alleviates liver fibrosis induced by MCDHF diet. Together, silencing IQGAP1 relieves liver fibrosis by blocking BMSC migration, providing an effective therapeutic strategy for liver fibrosis.

Neutrophil recruitment mediated by sphingosine 1-phosphate (S1P)/S1P receptors during chronic liver injury.

Excessive neutrophils are recruited to damaged tissue and cause collateral injury under chronic inflammatory conditions. Sphingosine 1-phosphate (S1P) modulates kinds of physiological and pathological actions by inducing recruitment of various cell types through S1P receptors (S1PRs). This study aimed to detect the S1P/S1PRs-mediated effects on neutrophil recruitment during chronic liver inflammation. In present study, increased neutrophils originated from bone marrow (BM) were detected in liver tissue of BDL-treated mice. Hepatic sphingosine kinase 1 (SphK, S1P rate-limiting enzyme) or S1P levels positively correlated with neutrophil marker expression in liver of mice and patients. In vitro, expression of S1PR1, S1PR2 and S1PR3 were detected in both mouse BM neutrophils and differentiated human neutrophil-like (dHL60) cells. S1P powerfully boosted the migration and cytoskeletal remodeling of BM neutrophils through S1PR1 or S1PR2. Different from BM neutrophils, the migration and cytoskeletal remodeling of dHL60 cells were mediated by S1PR2 or S1PR3. S1PR2 blockade obviously attenuates neutrophil infiltration in bile duct ligation (BDL)-induced mouse liver injury. In conclusion, S1P/S1PRs system plays a pivotal role in neutrophil recruitment.

Macrophage Sphingosine 1-Phosphate Receptor 2 Blockade Attenuates Liver Inflammation and Fibrogenesis Triggered by NLRP3 Inflammasome.

NLR family pyrin domain containing 3 (NLRP3) inflammasome accompanies chronic liver injury and is a critical mediator of inflammation-driven liver fibrosis. Sphingosine 1-phosphate (S1P)/S1P Receptor (S1PR) signaling participates in liver fibrogenesis by affecting bone marrow (BM)-derived monocytes/macrophage (BMM) activation. However, the relationship between S1P/S1PR signaling and NLRP3 inflammasome in BMMs remains unclear. Here, we found significantly elevated gene expression of NLRP3 inflammasome components (NLRP3, pro-interleukin-1ß, and pro-interleukin-18) and the activation of NLRP3 inflammasome significantly elevated during murine chronic liver injury induced by a bile duct ligation operation, a methionine-choline-deficient and high-fat diet, or carbon tetrachloride intraperitoneal injection. Moreover, the increased expression of sphingosine kinase 1 (SphK1), the rate-limiting synthetic enzyme of S1P, was positively correlated with NLRP3 inflammasome components in both patients and mouse model livers. Flow cytometry analysis and immunofluorescence staining showed BMMs contributed to the significant proportion of NLRP3+ cells in murine inflammatory livers, but not Kupffer cells, dendritic cells, endothelial cells, T cells, and hepatocytes. Focusing on macrophages, S1P promoted NLRP3 inflammasome priming and activation in a dose-dependent manner. Blockade of S1PR2 by JTE-013 (antagonist of S1PR2) or S1PR2-siRNA inhibited S1P-induced NLRP3 inflammasome priming and inflammatory cytokine (interleukin-1ß and interleukin-18) secretion, whereas blockade of S1PR1 or S1PR3 had no such effect. in vivo, a ß1,3-d-glucan-encapsulated siRNA particle (GeRP) delivery system is capable of silencing genes in macrophages specifically. Treatment with S1PR2 siRNA-GeRPs markedly reduced NLRP3 inflammasome priming and activation and attenuated liver inflammation and fibrosis. Together, the conclusions indicated that targeting macrophage S1PR2 retarded liver inflammation and fibrogenesis via downregulating NLRP3 inflammasome, which may represent an effective therapeutic strategy for chronic liver injury.

Cannabinoid Receptor 1/miR-30b-5p Axis Governs Macrophage NLRP3 Expression and Inflammasome Activation in Liver Inflammatory Disease.

Nod-like receptor (NLR) family pyrin domain containing 3 (NLRP3) has been regarded as an important initiator or promoter in multiple inflammatory diseases. However, the relationship between cannabinoid receptor 1 (CB1) and macrophage NLRP3 inflammasome and the corresponding molecular mechanism in liver inflammation remain unclear. Mouse liver injury models were induced by carbon tetrachloride (CCl4) or methionine-choline-deficient and high fat (MCDHF) diet. Human liver tissues were obtained from patients with different chronic liver diseases. CB1 expression was increased in liver tissue and macrophages of CCl4- and MCDHF-treated mice, positively correlated with NLRP3. CB1 agonist ACEA (Arachiodonyl-2'-Chloroethylamide) promoted NLRP3 expression and NLRP3 inflammasome activation in macrophages. CB1 blockade with its antagonist AM281 reduced NLRP3 expression, inflammasome activation, and liver inflammation in CCl4- and MCDHF-treated mice. MicroRNA-30b-5p (miR-30b-5p), screened by the intersection of bioinformatics databases and downregulated miRNAs in injured liver, negatively correlated with NLRP3 in mouse and human liver. miR-30b-5p was involved in CB1-mediated activation of NLRP3 inflammasome in macrophages by directly targeting NLRP3. Importantly, administration of miR-30b-5p agomir targeted NLRP3 and attenuated liver inflammation in the injured liver. Altogether, CB1/miR-30b-5p axis modulates NLRP3 expression and NLPR3 inflammasome activation in macrophages during liver inflammation, which provides a potential target for liver disease.

Gadolinium Chloride Restores the Function of the Gap Junctional Intercellular Communication between Hepatocytes in a Liver Injury.

BACKGROUND: Gadolinium chloride (GdCl3) has been reported to attenuate liver injury caused by a variety of toxicants. Gap junctional intercellular communication (GJIC) is thought to be essential in controlling liver homeostasis and pathology. Here we evaluate the effects of GdCl3 on functional GJIC and connexin expression in mouse models and primary hepatocytes. METHODS: Mice were administered GdCl3 intraperitoneally the day before a carbon tetrachloride (CCl4) injection or bile duct ligation (BDL) operation. Primary hepatocytes were treated with CCl4 or lipopolysaccharides (LPS), with or without GdCl3. A scrape loading/dye transfer assay was performed to assess the GJIC function. The expression of connexins was examined by real-time reverse transcription polymerase chain reaction (RT-PCR), western blot and immunofluorescent staining. RESULTS: CCl4 treatment or the BDL operation led to the dysfunction of GJIC and a down-regulation of Cx32 and Cx26 in injured liver. GdCl3 administration restored GJIC function between hepatocytes by facilitating the transfer of fluorescent dye from one cell into adjacent cells via GJIC, and markedly prevented the decrease of Cx32 and Cx26 in injured liver. In primary hepatocytes, CCl4 or LPS treatment induced an obvious decline of Cx32 and Cx26, whereas GdCl3 pretreatment prevented the down-regulation of connexins. In vivo GdCl3 protected hepatocytes and attenuated the liver inflammation and fibrosis in liver injury mouse models. CONCLUSION: GdCl3 administration protects functional GJIC between hepatocytes, and prevents the decrease of connexin proteins at mRNA and protein levels during liver injury, leading to the alleviation of chronic liver injury.

MicroRNA-26b-5p Inhibits Mouse Liver Fibrogenesis and Angiogenesis by Targeting PDGF Receptor-Beta.

Here microRNAs (miRNAs) with potentially therapeutic effects were screened and explored during liver fibrogenesis and angiogenesis via targeting the important mediators. Chimera mice with EGFP+ bone marrow mesenchymal stromal cells (BMSCs) were fed with methionine-choline-deficient and high-fat (MCDHF) diet to induce liver injury. Increased expression of platelet-derived growth factor receptor-beta (PDGFR-ß) was detected in MCDHF mice, with a positive correlation to fibrosis and angiogenesis markers. BMSCs contributed to the significant proportion of PDGFR-ß+ cells in the fibrotic liver. MicroRNA-26b-5p (miR-26b-5p) was predicted to target PDGFR-ß from three databases. The hepatic expression of miR-26b-5p was decreased in the fibrotic liver, with a negative correlation to PDGFR-ß and fibrosis and angiogenesis markers. miR-26b-5p directly targeted PDGFR-ß in TGF-ß1-treated BMSCs by pull-down and lucifer reporter assays, which can be sponged by long non-coding RNA (lncRNA) maternally expressed gene 3 (lncMEG3). Microarray analysis revealed that miR-26b-5p overexpression affected a list of genes associated with fibrosis and angiogenesis. In vivo miR-26b-5p negatively regulated PDGFR-ß expression and attenuated liver fibrosis and angiogenesis. Together, miR-26b-5p inhibits liver fibrogenesis and angiogenesis via directly targeting PDGFR-ß and interacting with lncMEG3, which may represent an effective therapeutic strategy for liver fibrosis.

The class D scavenger receptor CD68 contributes to mouse chronic liver injury.

Scavenger receptors, which are expressed on monocyte/macrophages, play a central role in many pathogenic processes. Here, we examined the role of the class D scavenger receptor (CD68) in bone marrow-derived monocyte/macrophages (BMMs) in chronic liver injury. The expression pattern of multiple scavenger receptors in two liver injury models (methionine-choline-deficient and high fat (MCDHF), carbon tetrachloride (CCl4)) were analyzed by qRT-PCR. CD68 expression was characterized by flow cytometric analysis, immunofluorescence, and qRT-PCR. A selective monocyte/macrophage toxicant, gadolinium chloride (GdCl3) was applied to analyze the function of CD68 in vitro and in vivo. Among the seven examined scavenger receptors (CD68, CD36, CD204, MARCO, LOX1, SREC, and CD163), the mRNA expression of CD68 first got uppermost and continuously increased throughout the entire stage of chronic liver injury, thus attracting our attention. In the injured liver, the percentage of recruited CD68+ BMM increased notably, aligning along the developing fibrotic septa, while the proportion of CD68+ KC stayed the same compared with that of control mice. In vitro CD68 was highly expressed in primary cultured BMM, and CD68 reduction was triggered by macrophage phagocytosis and apoptosis in the presence of GdCl3. In the damaged liver, the recruitment of CD68+ BMM and CD68 mRNA expression were reduced by GdCl3 administration, leading to the attenuation of liver inflammation and fibrosis. Altogether, scavenger receptor CD68 plays a key role in mouse chronic liver injury, which has important implications for the design of anti-fibrotic therapies.