The circAno6/miR-296-3p/TLR4 signaling axis mediates the inflammatory response to induce the activation of hepatic stellate cells

BACKGROUND

Circular RNA (circRNA) is a novel functional non-coding RNA(ncRNA) that plays a role in the occurrence and development of multiple human liver diseases, including liver fibrosis (LF). LF is a reversible repair response after liver injury, and the activation of hepatic stellate cells (HSCs) is the core event. However, the regulatory mechanisms by which circRNAs induce the activation of HSCs in LF are still poorly understood. The circAno6/miR-296-3p/toll-like receptor 4 (TLR4) signaling axis that mediates the inflammatory response and causes the activation of HSCs was investigated in this study.

METHODS

First, a circAno6 overexpression plasmid and small interfering RNA were transfected into cells to determine whether circAno6 can affect the function of HSCs. Second, real-time quantitative polymerase chain reaction (RT-qPCR), enzyme-linked immunosorbent assay (ELISA), western blotting (WB) and immunofluorescence (IF) were used to detect the effects of circAno6 plasmid/siRNA transfection on HSC activation indices, inflammatory markers and the circAno6/miR-296-3p/TLR4 signaling axis. The subcellular position of circAno6 was then examined by nucleo-cytoplasmic separation and fluorescence in situ hybridization (FISH). Finally, a luciferase reporter gene assay was used to identify the relationship between circAno6 and miR-296-3p as well as the relationship between miR-296-3p and TLR4.

RESULTS

CircAno6 was considerably upregulated in HSCs and positively correlated with cell proliferation and alpha-smooth muscle actin (α-SMA), collagen I, NOD-likereceptorthermalproteindomainassociatedprotein 3 (NLRP3), interleukin-1β (IL-1β) and interleukin-18 (IL-18) expression. Overexpression of circAno6 increased the inflammatory response and induced HSC activation, whereas interference resulted in the opposite effects. FISH experiments revealed the localization of circAno6 in the cytoplasm. Then, a double luciferase reporter assay confirmed that miR-296-3p significantly inhibited luciferase activity in the circAno6-WT and TLR4-WT groups.

CONCLUSION

This study suggests that circAno6 and miR-296-3p/TLR4 may form a regulatory axis and regulate the inflammatory response, which in turn induces HSC activation. Targeting circAno6 may be a potential therapeutic strategy to treat LF.

TREM2 protects against inflammation by regulating the release of mito-DAMPs from hepatocytes during liver fibrosis

BACKGROUND

Liver fibrosis typically develops as a result of chronic liver injury, which involves inflammatory and regenerative processes. The triggering receptor expressed on myeloid cells 2 (TREM2), predominantly expressing in hepatic non-parenchymal cells, plays a crucial role in regulating the function of macrophages. However, its mechanism in liver fibrosis remains poorly defined.

METHODS

Experimental liver fibrosis models in wild type and TREM2-/- mice, and in vitro studies with AML-12 cells and Raw264.7 cells were conducted. The expression of TREM2 and related molecular mechanism were evaluated by using samples from patients with liver fibrosis.

RESULTS

We demonstrated that TREM2 was upregulated in murine model with liver fibrosis. Mice lacking TREM2 exhibited reduced phagocytosis activity in macrophages following carbon tetrachloride (CCl4) intoxication. As a result, there was an increased accumulation of necrotic apoptotic hepatocytes. Additionally, TREM2 knockout aggravated the release of mitochondrial damage-associated molecular patterns (mito-DAMPs) from dead hepatocytes during CCl4 exposure, and further promoted the occurrence of macrophage-mediated M1 polarization. Then, TREM2-/- mice showed more serious fibrosis pathological changes. In vitro, the necrotic apoptosis inhibitor GSK872 effectively alleviated the release of mito-DAMPs in AML-12 cells after CCl4 intoxication, which confirmed that mito-DAMPs originated from dead liver cells. Moreover, direct stimulation of Raw264.7 cells by mito-DAMPs from liver tissue can induce intracellular inflammatory response. More importantly, TREM2 was elevated and inflammatory factors were markedly accumulated surrounding dead cells in the livers of human patients with liver fibrosis.

CONCLUSION

Our study highlights that TREM2 serves as a negative regulator of liver fibrosis, suggesting its potential as a novel therapeutic target.

Calcitriol Inhibits NaAsO2 Triggered Hepatic Stellate Cells Activation and Extracellular Matrix Oversecretion by Activating Nrf2 Signaling Pathway Through Vitamin D Receptor

Previous studies, including our own, have demonstrated that arsenic exposure can induce liver fibrosis, while the underlying mechanism remains unclear and there is currently no effective pharmacological intervention available. Recent research has demonstrated that vitamin D supplementation can ameliorate liver fibrosis caused by various etiologies, potentially through modulation of the Nrf2 signaling pathways. However, it remains unclear whether vitamin D intervention can mitigate arsenic-caused liver fibrosis. As is known hepatic stellate cells (HSCs) activation and extracellular matrix (ECM) deposition are pivotal in the pathogenesis of liver fibrosis. In this study, we investigated the intervention effect of calcitriol (a form of active vitamin D) on arsenite-triggered Lx-2 cells (a human hepatic stellate cell line) activation and ECM oversecretion. Additionally, we also elucidated the role and mechanism of Nrf2 antioxidant signaling pathway. Our results demonstrated that calcitriol intervention significantly inhibits Lx-2 cell activation and ECM oversecretion induced by arsenite exposure. Additionally, calcitriol activates Nrf2 and its downstream antioxidant enzyme expression in Lx-2 cells, thereby reducing ROS overproduction caused by arsenite exposure. Further investigation reveals that calcitriol activates the Nrf2 signaling pathway and inhibits arsenite-triggered Lx-2 cell activation and ECM oversecretion by targeting vitamin D receptor (VDR). In conclusion, this study has demonstrated that vitamin D intervention can effectively inhibit HSC activation and ECM oversecretion triggered by arsenite exposure through its antioxidant activity. This provides a novel strategy for targeted nutritional intervention in the treatment of arsenic-induced liver fibrosis.

Arctigenin induces activated HSCs quiescence via AMPK-PPARγ pathway to ameliorate liver fibrosis in mice

Arctigenin (ATG), a traditional Chinese herbal medicine, is a natural lignan compound extracted from the seeds of burdock (Arctium lappa L, Asteraceae). As a natural product with multiple biological activities, the effect and mechanism of ATG against liver fibrosis are not fully elucidated yet. In current work, we first discovered that ATG could improve CCl4-induced liver injury reflected by lower plasma ALT and AST levels, liver coefficient and pathological scoring of ballooning. Furthermore, it also could reduce the positive areas of Masson, Sirius red and α-SMA staining, inhibit the expression of fibrosis-related genes (Col1a1, Col3a1, Acta2), and decrease the content of hydroxyproline, indicated ATG treatment had benefits in alleviating CCl4-induced liver fibrosis. In vitro, we observed that ATG can inhibit collagen production stimulated by TGF-β1 in LX2 cells. By analysis of the information obtained from SymMap and GeneCards databases and in vitro validation experiments, ATG was proven to be an indirect PPARγ agonist and its effect on collagen production was dependent on PPARγ. Subsequently, we confirmed that ATG activating AMPK was the contributor of its effect on PPARγ and collagen production. Finally, the transformation of activated hepatic stellate cells was determined after treated with ATG, in which ATG treatment could return activated LX2 cells to quiescence because of the elevated quiescent markers and lipid droplets. Our work has highlighted the potential of ATG in the treatment of liver fibrosis and clarified that ATG can activate AMPK/PPARγ pathway to restore the activated hepatic stellate cell to quiescence thereby improving liver fibrosis.

Nephronophthisis: a pathological and genetic perspective

Nephronophthisis (NPHP) is an autosomal recessive cystic kidney disease and is one of the most frequent genetic causes for kidney failure (KF) in children and adolescents. Over 20 genes cause NPHP and over 90 genes contribute to renal ciliopathies often involving multiple organs. About 15-20% of NPHP patients have additional extrarenal symptoms affecting other organs than the kidneys. The involvement of additional organ systems in syndromic forms of NPHP is explained by shared expression of most NPHP gene products in centrosomes and primary cilia, a sensory organelle present in most mammalian cells. This finding resulted in the classification of NPHP as a ciliopathy. If extrarenal symptoms are present in addition to NPHP, these disorders are defined as NPHP-related ciliopathies (NPHP-RC) and can involve the retina (e.g., with Senior-Løken syndrome), CNS (central nervous system) (e.g., with Joubert syndrome), liver (e.g., Boichis and Arima syndromes), or bone (e.g., Mainzer-Saldino and Sensenbrenner syndromes). This review focuses on the pathological findings and the recent genetic advances in NPHP and NPHP-RC. Different mechanisms and signaling pathways are involved in NPHP ranging from planar cell polarity, sonic hedgehog signaling (Shh), DNA damage response pathway, Hippo, mTOR, and cAMP signaling. A number of therapeutic interventions appear to be promising, ranging from vasopressin receptor 2 antagonists such as tolvaptan, cyclin-dependent kinase inhibitors such as roscovitine, Hh agonists such as purmorphamine, and mTOR inhibitors such as rapamycin.

The Utility of a Novel Stacked Microvascular Imaging for Enhanced Detection of Fibrosis in Chronic Liver Diseases

OBJECTIVE

Ultrasonographic imaging plays a primary role to detect fibrotic changes in patients with chronic liver disease (CLD). To enhance detectability of fibrosis in its early stage, we developed a novel stacked microvascular imaging (SMVI) that enables continuous visualization of fibrotic changes in intrahepatic vessels.

METHODS

SMVI was produced by accumulating 3-5 seconds of high-definition color images in tilted-scan mode. An SMVI score was devised by quantitating three hallmark vascular changes in liver fibrosis in 0-2 grades (total 0-6): narrowing, caliber irregularity, and tortuosity. To evaluate the clinical utility of the SMVI score, 469 well-defined CLD patients were enrolled and subgrouped by the stage of liver fibrosis defined based on elastography: F0-1Low, F0-1High, F2, F3, and F4. The diagnostic performance of the SMVI score was compared to conventional B-mode liver morphology score and various laboratory test markers of fibrosis.

RESULTS

Unlike conventional microvascular imaging that relies on a single image, SMVI enabled an undisrupted view of intrahepatic vessels for easy detection of fibrotic changes. SMVI detected microvascular narrowing in 92% at stage F0-1High. While detection rates for caliber irregularity and tortuosity were low at early stages but increased proportionately in advanced stages. Multiple logistic regression analysis revealed that SMVI score was most accurate in distinguishing F0-1Low from F0-1High cases compared to B-mode or laboratory test scores.

CONCLUSION

SMVI provides enhanced vascular images of liver fibrosis in CLD, especially in its early stage. The SMVI score can be used as a primary tool for determining fibrotic stages in CLD.

Penthorum chinense Pursh leaf tea debittering mechanisms via green tea manufacturing process and its influence on NAFLD-alleviation activities

The green-tea manufacturing process showed good effect of flavor improving, debittering and shaping in making Penthorum chinensePursh leaf (PL) tea (PLT), which serves as a polyphenol dietary supplement and beverage raw material. GC-MS results showed that its unpleasant grassy odor decreased by 42.8% due to dodecanal, geranylacetone, and (E)-2-nonenal reduction, coupled with 1-hexadecanol increasing. UPLC-ESI-TOF-MS identified 95 compounds and showed that the debittering effect of green-tea manufacturing process was attributed to decreasing of flavonols and lignans, especially quercetins, kaempferols and luteolins, and increasing of dihydrochalcones which act as sweeteners bitterness-masking agents, while astringency was weakened by reducing delphinidin-3,5-O-diglucoside chloride, kaempferol-7-O-β-d-glucopyranoside, and tannins. The increase of pinocembrins and catechins in aqueous extracts of PLT, maintained its hepatoprotective, NAFLD-alleviation, and hepatofibrosis-prevention activities similar to PL in high fat-diet C57BL/6 mice, with flavonoids, tannins, tannic acids, and some newfound chemicals, including norbergenin, gomisin K2, pseudolaric acid B, tanshinol B, as functional ingredients.

Progress in clinical and basic research of fuzheng Huayu formula for the treatment of liver fibrosis

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese medicine has great potential and advantages in the treatment of liver fibrosis, with Fuzheng Huayu formula (FZHY) serving as a prime example due to its remarkable efficacy in delaying and reversing liver fibrosis while simultaneously improving clinical symptoms for patients.

AIM OF THE REVIEW

In this paper, we present a comprehensive review of recent studies on the therapeutic potential of FZHY and its components/ingredients in the treatment of liver fibrosis and cirrhosis, with the aim of providing insights for future research endeavors.

MATERIALS AND METHODS

A comprehensive literature search was conducted on FZHY, TCM319, traditional Chinese medicine 319, liver fibrosis and cirrhosis using multiple internationally recognized databases including PubMed, Embase, Springer, Web of science, SciVerse ScienceDirect, Clinical Trails. Gov, CNKI, Wanfang, and VIP.

RESULTS

FZHY is widely used clinically for liver fibrosis and cirrhosis caused by various chronic liver diseases, with the effects of improving serum liver function, liver pathological histology, serological indices related to liver fibrosis, decreasing liver stiffness values and portal hypertension, as well as reducing the incidence of hepatocellular carcinoma and morbidity/mortality in patients with cirrhosis. Numerous in vivo and in vitro experiments have demonstrated that FZHY possesses anti-fibrotic effects by inhibiting hepatic stellate cell activation, reducing inflammation, protecting hepatocytes, inhibiting hepatic sinusoidal capillarization and angiogenesis, promoting extracellular matrix degradation, and facilitating liver regeneration. In recent years, there has been a growing focus on investigating the primary active components/ingredients of FZHY, and significant strides have been made in comprehending their synergistic mechanisms that enhance efficacy.

CONCLUSION

FZHY is a safe and effective drug for treating liver fibrosis. Future research on FZHY should focus on its active components/ingredients and their synergistic effects, as well as the development of modern cocktail drugs based on its components/ingredients. This will facilitate a more comprehensive understanding of the molecular mechanisms and targets of FZHY in treating liver fibrosis, thereby further guide clinical applications and drug development.

Yinchen gongying decoction mitigates CCl4-induced chronic liver injury and fibrosis in mice implicated in inhibition of the FoxO1/TGF-β1/ Smad2/3 and YAP signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Liver fibrosis (LF) is a common reversible consequence of chronic liver damage with limited therapeutic options. Yinchen Gongying decoction (YGD) composed of two homologous plants: (Artemisia capillaris Thunb, Taraxacum monochlamydeum Hand.-Mazz.), has a traditionally application as a medicinal diet for acute icteric hepatitis. However, its impact on LF and underlying mechanisms remain unclear.

AIM OF THE STUDY

This study aims to assess the impact of YGD on a carbon tetrachloride (CCl4) induced liver fibrosis and elucidate its possible mechanisms. The study seeks to establish an experimental foundation for YGD as a candidate drug for hepatic fibrosis.

MATERIALS AND METHODS

LC-MS/MS identified 11 blood-entry components in YGD, and network pharmacology predicted their involvement in the FoxO signaling pathway, insulin resistance, and PI3K-AKT signaling pathway. Using a CCl4-induced LF mouse model, YGD's protective effects were evaluated in comparison to a positive control and a normal group. The underlying mechanisms were explored through the assessments of hepatic stellate cells (HSCs) activation, fibrotic signaling, and inflammation.

RESULTS

YGD treatment significantly improved liver function, enhanced liver morphology, and reduced liver collagen deposition in CCl4-induced LF mice. Mechanistically, YGD inhibited HSC activation, elevated MMPs/TIMP1 ratios, suppressed the FoxO1/TGF-β1/Smad2/3 and YAP pathways, and exhibited anti-inflammatory and antioxidant effects. Notably, YGD improved the insulin signaling pathway.

CONCLUSION

YGD mitigates LF in mice by modulating fibrotic and inflammatory pathways, enhancing antioxidant responses, and specifically inhibiting FoxO1/TGF-β1/Smad2/3 and YAP signal pathways.

Alpha-fetoprotein and APRI as predictive markers for patients with Type C hepatitis B-related acute-on-chronic liver failure: a retrospective study

BACKGROUND

Type C hepatitis B-related acute-on-chronic liver failure (HBV-ACLF), which is based on decompensated cirrhosis, has different laboratory tests, precipitating events, organ failure and clinical outcomes. The predictors of prognosis for type C HBV-ACLF patients are different from those for other subgroups. This study aimed to construct a novel, short-term prognostic score that applied serological indicators of hepatic regeneration and noninvasive assessment of liver fibrosis to predict outcomes in patients with type C HBV-ACLF.

METHOD

Patients with type C HBV-ACLF were observed for 90 days. Demographic information, clinical examination, and laboratory test results of the enrolled patients were collected. Univariate and multivariate logistic regression were performed to identify independent prognostic factors and develop a novel prognostic scoring system. A receiver operating characteristic (ROC) curve was used to analyse the performance of the model.

RESULTS

A total of 224 patients with type C HBV-ACLF were finally included. The overall survival rate within 90 days was 47.77%. Age, total bilirubin (TBil), international normalized ratio (INR), alpha-fetoprotein (AFP), white blood cell (WBC), serum sodium (Na), and aspartate aminotransferase/platelet ratio index (APRI) were found to be independent prognostic factors. According to the results of the logistic regression analysis, a new prognostic model (named the A3Twin score) was established. The area under the curve (AUC) of the receiver operating characteristic curve (ROC) was 0.851 [95% CI (0.801-0.901)], the sensitivity was 78.8%, and the specificity was 71.8%, which were significantly higher than those of the MELD, IMELD, MELD-Na, TACIA and COSSH-ACLF II scores (all P < 0.001). Patients with lower A3Twin scores (<-9.07) survived longer.

CONCLUSIONS

A new prognostic scoring system for patients with type C HBV-ACLF based on seven routine indices was established in our study and can accurately predict short-term mortality and might be used to guide clinical management.

Mechanistic insight into the hepatoprotective effect of Moringa oleifera Lam leaf extract and telmisartan against carbon tetrachloride-induced liver fibrosis: plausible roles of TGF-β1/SMAD3/SMAD7 and HDAC2/NF-κB/PPARγ pathways

The increasing prevalence and limited therapeutic options for liver fibrosis necessitates more medical attention. Our study aims to investigate the potential molecular targets by which Moringa oleifera Lam leaf extract (Mor) and/or telmisartan (Telm) alleviate carbon tetrachloride (CCl4)-induced liver fibrosis in rats. Liver fibrosis was induced in male Sprague-Dawley rats by intraperitoneal injection of 50% CCl4 (1 ml/kg) every 72 hours, for 8 weeks. Intoxicated rats with CCl4 were simultaneously orally administrated Mor (400 mg/kg/day for 8 weeks) and/or Telm (10 mg/kg/day for 8 weeks). Treatment of CCl4-intoxicated rats with Mor/Telm significantly reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities compared to CCl4 intoxicated group (P < 0.001). Additionally, Mor/Telm treatment significantly reduced the level of hepatic inflammatory, profibrotic, and apoptotic markers including; nuclear factor-kappa B (NF-κB), tumor necrosis factor-alpha (TNF-α), transforming growth factor-βeta1 (TGF-β1), and caspase-3. Interestingly, co-treatment of CCl4-intoxicated rats with Mor/Telm downregulated m-RNA expression of histone deacetylase 2 (HDAC2) (71.8%), and reduced protein expression of mothers against decapentaplegic homolog 3 (p-SMAD3) (70.6%) compared to untreated animals. Mor/Telm regimen also elevated p-SMAD7 protein expression as well as m-RNA expression of peroxisome proliferator-activated receptor γ (PPARγ) (3.6 and 3.1 fold, respectively p < 0.05) compared to CCl4 intoxicated group. Histopathological picture of the liver tissue intoxicated with CCl4 revealed marked improvement by Mor/Telm co-treatment. Conclusively, this study substantiated the hepatoprotective effect of Mor/Telm regimen against CCl4-induced liver fibrosis through suppression of TGF-β1/SMAD3, and HDAC2/NF-κB signaling pathways and up-regulation of SMAD7 and PPARγ expression.

Lower HBV DNA level is associated with more severe liver fibrosis in HBeAg-positive chronic hepatitis B with normal alanine transaminase

BACKGROUND

The association of hepatitis B virus (HBV) DNA levels and liver fibrosis in chronic hepatitis B (CHB) patients with immune-tolerant phase remains unclear. We explored the association between liver fibrosis and HBV DNA levels in HBeAg-positive CHB patients with normal alanine transaminase (ALT) with relatively high HBV DNA.

METHODS

Six hundred and twenty-two HBeAg-positive CHB patients with normal ALT were included. Patients were divided into three categories: low (6 log10 IU/mL ≤ HBV DNA < 7 log10 IU/mL), moderate (7 log10 IU/mL ≤ HBV DNA < 8 log10 IU/mL), and high (HBV DNA ≥ 8 log10 IU/mL). APRI, FIB-4, transient elastography, or liver biopsy were used to assess liver fibrosis.

RESULTS

The median age of patients was 33.0 years and 57.9% patients were male. 18.8%, 52.1%, and 29.1% of patients had low, moderate, and high HBV DNA levels, respectively. The APRI (0.33 vs. 0.26 vs. 0.26, P < 0.001), FIB-4 (1.03 vs. 0.71 vs. 0.68, P < 0.001), and LSM values (7.6 kPa vs. 5.6 kPa vs. 5.5 kPa, P = 0.086) were higher in low HBV DNA group than other two groups. Low HBV DNA group had higher proportions of significant fibrosis (24.8% vs. 9.9% vs. 3.3%, P < 0.001) and cirrhosis (7.7% vs. 2.5% vs. 1.1%, P = 0.004) than moderate and high HBV DNA groups. Moderate (OR 3.095, P = 0.023) and low (OR 4.968, P = 0.003) HBV DNA were independent risk factors of significant fibrosis.

CONCLUSION

Lower HBV DNA level was associated with more severe liver fibrosis in HBeAg-positive CHB patients with ALT.

Resveratrol Alleviates Arsenic Exposure-Induced Liver Fibrosis in Rats by Inhibiting Hepatocyte Senescence

Arsenic is an environmental pollutant that has garnered considerable attention from the World Health Organization. Liver fibrosis is an advanced pathological stage of liver injury that can be caused by chronic arsenic exposure and has the potential to be reversed to prevent cirrhosis and hepatic malignancies. However, effective treatment options are currently limited. Given the profibrogenic effect of hepatocyte senescence, we established a rat model of sub-chronic sodium arsenite exposure and investigated the ability of resveratrol (RSV), a potential anti-senescence agent, to ameliorate arsenic-induced liver fibrosis and elucidate the underlying mechanism from the perspective of hepatocyte senescence. The results demonstrated that RSV was capable of mitigating fibrosis phenotypes in rat livers, including the activation of hepatic stellate cell (HSC), the generation of extracellular matrix, and the deposition of collagen fibers in the liver vascular zone, which are all induced by arsenic exposure. Furthermore, as an activator of the longevity factor SIRT1, RSV antagonized the arsenic-induced inhibition of SIRT1 expression, thereby restoring the suppression of the senescence protein p16 by SIRT1. This prevented arsenic-induced hepatocyte senescence, manifesting as a decrease in telomere shortening and a reduction in the release of senescence-associated secretory phenotype (SASP)-related proteins. In conclusion, this study demonstrated that RSV counteracts arsenic-induced hepatocyte senescence and the release of SASP-related proteins by restoring the inhibitory effect of SIRT1 on p16, thereby suppressing the activation of fibrotic phenotypes and mitigating liver fibrosis. These findings provide new insights for understanding the mechanism of arsenic-induced liver fibrosis, and more importantly, they reveal novel potential interventional approaches.

Progress of mesenchymal stem cells (MSCs) & MSC-Exosomes combined with drugs intervention in liver fibrosis

Liver fibrosis is an intrahepatic chronic damage repair response caused by various reasons such as alcoholic liver, fatty liver, viral hepatitis, autoimmune diseases, etc., and is closely related to the progression of liver disease. Currently, the mechanisms of liver fibrosis and its treatment are hot research topics in the field of liver disease remedy. Mesenchymal stem cells (MSCs) are a class of adult stem cells with self-renewal and multidirectional differentiation potential, which can ameliorate fibrosis through hepatic-directed differentiation, paracrine effects, and immunomodulation. However, the low inner-liver colonization rate, low survival rate, and short duration of intervention after stem cell transplantation have limited their wide clinical application. With the intensive research on liver fibrosis worldwide, it has been found that MSCs and MSCs-derived exosomes combined with drugs have shown better intervention efficiency than utilization of MSCs alone in many animal models of liver fibrosis. In this paper, we review the interventional effects and mechanisms of mesenchymal stem cells and their exosomes combined with drugs to alleviate hepatic fibrosis in vivo in animal models in recent years, which will provide new ideas to improve the efficacy of mesenchymal stem cells and their exosomes in treating hepatic fibrosis in the clinic.

Head-to-Head Comparison of Hepatic Vein and Superior Vena Cava Flow Velocity Waveform Analyses for Predicting Elevated Right Atrial Pressure

OBJECTIVE

Blood flow in the hepatic veins and superior vena cava (SVC) reflects right heart filling; however, their Doppler profiles are often not identical, and no studies have compared their diagnostic efficacies. We aimed to determine which venous Doppler profile is reliable for detecting elevated right atrial pressure (RAP).

METHODS

In 193 patients with cardiovascular diseases who underwent cardiac catheterization within 2 d of echocardiography, the hepatic vein systolic filling fraction (HV-SFF) and the ratio of the peak systolic to diastolic forward velocities of the SVC (SVC-S/D) were measured. HV-SFF < 55% and SVC-S/D < 1.9 were regarded as elevated RAP. We also calculated the fibrosis 4 index (FIB-4) as a serum liver fibrosis marker.

RESULTS

HV-SFF and SVC-S/D were feasible in 177 (92%) and 173 (90%) patients, respectively. In the 161 patients in whom both venous Doppler waveforms could be measured, HV-SFF and SVC-S/D were inversely correlated with RAP (r = -0.350, p < 0.001; r = -0.430, p < 0.001, respectively). SVC-S/D > 1.9 showed a significantly higher diagnostic accuracy of RAP elevation compared with HV-SFF < 55% (area under the curve, 0.842 vs. 0.614, p < 0.001). Multivariate analyses showed that both FIB-4 (β = -0.211, p = 0.013) and mean RAP (β = -0.319, p < 0.001) were independent determinants of HV-SFF. In contrast, not FIB-4 but mean RAP (β = -0.471, p < 0.001) was an independent determinant of SVC-S/D. The diagnostic accuracy remained unchanged when HV-SFF < 55% was considered in conjunction with the estimated RAP based on the inferior vena cava morphology. Conversely, SVC-S/D showed an incremental diagnostic value over the estimated RAP.

CONCLUSIONS

SVC-S/D enabled a more accurate diagnosis of RAP elevation than HV-SFF.

Association between serum vitamin D concentration and liver fibrosis in diabetes mellitus patients: a cross-sectional study from the NHANES database

AIM

Liver fibrosis (LF) is a common complication of diabetes mellitus (DM). Studies have found that vitamin D (VD), as a modifiable factor has been reported to be associated with LF. The relationship between serum VD concentration and LF in DM patients has rarely been reported. The aim of this study was to assess the association between serum VD concentration and LF in DM patients.

METHODS

In this cross-sectional study, data of DM patients aged ≥ 45 years were extracted from the National Health and Nutrition Examination Survey (NHANES 2017-2018). Serum VD concentration was measured by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Vibration controlled transient elastography (VCTE) was used to measure liver stiffness. Covariates included sociodemographic information, lifestyles, laboratory data, diseases history were extracted from the database. The weighted univariable and multivariable logistic regression models were utilized to explore the association between serum VD concentration and LF in DM patients, and were described as odds ratio (ORs) and 95% confidence intervals (CIs). Subgroup analyses based on BMI, liver steatosis, hypertension and dyslipidemia were further assessed the association.

RESULTS

A total of 799 patients were included, of which 188 (23.53%) had LF. Higher serum VD concentration was associated with the lower odds of LF (OR = 0.33, 95% CI 0.19-0.59) and advanced LF (OR = 0.31, 95% CI 0.17-0.55) in DM patients after adjustment for race, liver steatosis, BMI, smoking, drinking, AST, ALT and physical activity, especially in patients with liver steatosis (OR = 0.28, 95% CI 0.13-0.59) and dyslipidemia (OR = 0.31, 95% CI 0.14-0.66), respectively.

CONCLUSIONS

High serum VD concentration may have a potential benefit for maintain the liver health in DM patients.

Associations between metabolic dysfunction-associated fatty liver disease, chronic kidney disease, and abdominal obesity: a national retrospective cohort study

Metabolic dysfunction-associated fatty liver disease (MAFLD) and chronic kidney disease (CKD) present notable health challenges, however, abdominal obesity has received scant attention despite its potential role in exacerbating these conditions. Thus, we conducted a retrospective cohort study using the National Health and Nutrition Examination Surveys III (NHANES III) of the United States from 1988 to 1994 including 9161 participants, and mortality follow-up survey in 2019. Statistical analyze including univariable and multivariable Logistic and Cox regression models, and Mediation effect analyze were applied in study after adjustment for covariates. Our findings revealed that individuals with both abdominal obesity and MAFLD were more likely to be female, older and exhibit higher prevalence of advanced liver fibrosis (7.421% vs. 2.363%, p < 0.001), type 2 diabetes mellitus (T2DM) (21.484% vs. 8.318%, p < 0.001) and CKD(30.306% vs. 16.068%, p < 0.001) compared to those with MAFLD alone. MAFLD (adjusted OR: 1.392, 95% CI 1.013-1.913, p = 0.041), abdominal obesity (adjusted OR 1.456, 95% CI 1.127-1.880, p = 0.004), abdominal obesity with MAFLD (adjusted OR 1.839, 95% CI 1.377-2.456, p < 0.001), advanced fibrosis(adjusted OR 1.756, 95% CI 1.178-2.619, p = 0.006) and T2DM (adjusted OR 2.365, 95% CI 1.758-3.183, p < 0.001) were independent risk factors of CKD. The abdominal obese MAFLD group had the highest all-cause mortality as well as mortality categorized by disease during the 30-year follow-up period. Indices for measuring abdominal obesity, such as waist circumference (WC), waist-hip ratio (WHR), and lipid accumulation product (LAP), elucidated a greater mediation effect of MAFLD on CKD compared to BMI on CKD (proportion mediation 65.23%,70.68%, 71.98%, respectively vs. 32.63%). In conclusion, the coexistence of abdominal obesity and MAFLD increases the prevalence and mortality of CKD, and abdominal obesity serves as a mediator in the association between MAFLD and CKD.

Knockdown of circ_0044226 promotes endoplasmic reticulum stress-mediated autophagy and apoptosis in hepatic stellate cells via miR-4677-3p/SEC61G axis

Downregulation of circ_0044226 has been demonstrated to reduce pulmonary fibrosis, but the role of circ_0044226 in liver fibrosis remains to be explored. In this work, we found that circ_0044226 expression was upregulated during liver fibrosis. Knockdown of circ_0044226 inhibited proliferation, promoted autophagy and apoptosis of hepatic stellate cell LX-2. Bioinformatic analysis and dual luciferase reporter assays confirmed the interaction between circ_0044226, miR-4677-3p and SEC61G. Mechanistically, knockdown of circ_0044226 suppressed SEC61G expression by releasing miR-4677-3p, thereby enhancing endoplasmic reticulum stress. Overexpression of SEC61G or endoplasmic reticulum stress inhibitor 4-phenylbutiric acid partially reversed the effect of knockdown circ_0044226 on LX-2 cell function. In vivo experiments showed that inhibition of circ_0044226 attenuated CCL4-induced liver fibrosis in mice. These imply that circ_0044226 may be a potential target for the treatment of liver fibrosis.

Structural characterization and therapeutic effect of Alhagi honey oligosaccharide on liver fibrosis in mice

Alhagi honey is derived from the secretory granules of Alhagi pseudoalhagi Desv., a leguminous plant commonly known as camelthorn. Modern medical research has demonstrated that the extract of Alhagi honey possesses regulatory properties for the gastrointestinal tract and immune system, as well as exerts anti-tumor, anti-oxidative, anti-inflammatory, anti-bacterial, and hepatoprotective effects. The aim of this study was to isolate and purify oligosaccharide monomers (referred to as Mel) from camelthorn and elucidate their structural characteristics. Subsequently, the impact of Mel on liver injury induced by carbon tetrachloride (CCl4) in mice was investigated. The analysis identified the isolated oligosaccharide monomer (α-D-Glcp-(1 → 3)-β-D-Fruf-(2 → 1)-α-D-Glcp), with the molecular formula C18H32O16. In a mouse model of CCl4-induced liver fibrosis, Mel demonstrated significant therapeutic effects by attenuating the development of fibrosis. Moreover, it enhanced anti-oxidant enzyme activity (glutathione peroxidase and superoxide dismutase) in liver tissues, thereby reducing oxidative stress markers (malondialdehyde and reactive oxygen species). Mel also improved serum albumin levels, lowered liver enzyme activities (aspartate aminotransferase and alanine aminotransferase), and decreased inflammatory factors (tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-6). Immunohistochemistry, immunofluorescence, and western blotting analyses confirmed the ability of Mel to downregulate hepatic stellate cell-specific markers (collagen type I alpha 1 chain, alpha-smooth muscle actin, transforming growth factor-beta 1. Non-targeted metabolomics analysis revealed the influence of Mel on metabolic pathways related to glutathione, niacin, pyrimidine, butyric acid, and amino acids. In conclusion, the results of our study highlight the promising potential of Mel, derived from Alhagi honey, as a viable candidate drug for treating liver fibrosis. This discovery offers a potentially advantageous option for individuals seeking natural and effective means to promote liver health.

Hepatoprotective effects of paeonol by suppressing hepatic stellate cell activation via inhibition of SMAD2/3 and STAT3 pathways

Hepatic stellate cell (HSC) activation is a key event in extracellular matrix accumulation, causing hepatic fibrosis. Therefore, identifying chemicals that inhibit HSC activation is an important therapeutic strategy for hepatic fibrosis. The aim of this study was to investigate the therapeutic effects of paeonol on HSC activation. In LX-2 cells, paeonol inhibited the expression of collagen and decreased the expression of HSC activation markers. In mice with thioacetamide-induced liver fibrosis, paeonol treatment decreased the serum levels of aspartate aminotransferase and alanine transaminase and mRNA expression of α-smooth muscle actin, platelet-derived growth factor-β, and connective-tissue growth factor. Investigation of the underlying molecular mechanism of paeonol showed that paeonol inhibits the SMAD2/3 and STAT3 signaling pathways that are important for HSC activation. On the basis of these results, paeonol should be investigated and developed further for hepatic fibrosis treatment.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01440-9.

The antiprotozoal drug nitazoxanide improves experimental liver fibrosis in mice

Nitazoxanide is an FDA-approved antiprotozoal drug. Our previous studies find that nitazoxanide and its metabolite tizoxanide affect AMPK, STAT3, and Smad2/3 signals which are involved in the pathogenesis of liver fibrosis, therefore, in the present study, we examined the effect of nitazoxanide on experimental liver fibrosis and elucidated the potential mechanisms. The in vivo experiment results showed that oral nitazoxanide (75, 100 mg·kg-1) significantly improved CCl4- and bile duct ligation-induced liver fibrosis in mice. Oral nitazoxanide activated the inhibited AMPK and inhibited the activated STAT3 in liver tissues from liver fibrosis mice. The in vitro experiment results showed that nitazoxanide and its metabolite tizoxanide activated AMPK and inhibited STAT3 signals in LX-2 cells (human hepatic stellate cells). Nitazoxanide and tizoxanide inhibited cell proliferation and collagen I expression and secretion of LX-2 cells. Nitazoxanide and tizoxanide inhibited transforming growth factor-β1 (TGF-β1)- and IL-6-induced increases of cell proliferation, collagen I expression and secretion, inhibited TGF-β1- and IL-6-induced STAT3 and Smad2/3 activation in LX-2 cells. In mouse primary hepatic stellate cells, nitazoxanide and tizoxanide also activated AMPK, inhibited STAT3 and Smad2/3 activation, inhibited cell proliferation, collagen I expression and secretion. In conclusion, nitazoxanide inhibits liver fibrosis and the underlying mechanisms involve AMPK activation, and STAT3 and Smad2/3 inhibition.

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.

Recruitment or activation of mast cells in the liver aggravates the accumulation of fibrosis in carbon tetrachloride-induced liver injury

Liver diseases caused by viral infections, alcoholism, drugs, or chemical poisons are a significant health problem: Liver diseases are a leading contributor to mortality, with approximately 2 million deaths per year worldwide. Liver fibrosis, as a common liver disease characterized by excessive collagen deposition, is associated with high morbidity and mortality, and there is no effective treatment. Numerous studies have shown that the accumulation of mast cells (MCs) in the liver is closely associated with liver injury caused by a variety of factors. This study investigated the relationship between MCs and carbon tetrachloride (CCl4)-induced liver fibrosis in rats and the effects of the MC stabilizers sodium cromoglycate (SGC) and ketotifen (KET) on CCl4-induced liver fibrosis. The results showed that MCs were recruited or activated during CCl4-induced liver fibrosis. Coadministration of SCG or KET alleviated the liver fibrosis by decreasing SCF/c-kit expression, inhibiting the TGF-β1/Smad2/3 pathway, depressing the HIF-1a/VEGF pathway, activating Nrf2/HO-1 pathway, and increasing the hepatic levels of GSH, GSH-Px, and GR, thereby reducing hepatic oxidative stress. Collectively, recruitment or activation of MCs is linked to liver fibrosis and the stabilization of MCs may provide a new approach to the prevention of liver fibrosis.