Mechanisms of hepatic fibrogenesis

The role and molecular mechanism of CTHRC1 in fibrosis

Fibrosis, a pathological state characterized by the excessive accumulation of extracellular matrix components, is primarily driven by the overactivation of fibroblasts. This condition becomes particularly pronounced under chronic inflammatory conditions. Fibrosis can occur in several tissues throughout the body. Among the notable discoveries in the study of fibrosis is the role of Collagen Triple Helix Repeat Containing-1 (CTHRC1), a protein that has emerged as a critical regulator in the fibrotic process. CTHRC1 is rapidly expressed on the outer membrane of fibroblasts and intimal smooth muscle cells following vascular injury, such as that induced by balloon angioplasty. This expression denotes the organism efforts to repair and restructure compromised tissue, signifying a critical component of the tissue repair mechanism in reaction to fibrosis. It plays a pivotal role in promoting cell migration and aiding tissue repair post-injury, contributing significantly to various pathophysiological processes including revascularization, bone formation, developmental morphological changes, inflammatory arthritis, and the progression of cancer. Significantly, researchers have observed marked expression of CTHRC1 across a variety of fibrotic conditions, closely associating it with the progression of the disease. Intervention with CTHRC1 can affect the occurrence and progression of fibrosis. This review aims to comprehensively explore the role and underlying mechanisms of CTHRC1 in fibrotic diseases, highlighting its potential as a key target for therapeutic interventions.

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.

Effects of Bulleyaconitine A on Extracellular Matrix Secretion and Expression of Related Proteins in Acetaldehyde-Activated Hepatic Stellate Cells

Activated hepatic stellate cells differentiate into myofibroblasts, which synthesize and secrete extracellular matrix (ECM) leading to liver fibrosis. It was previously demonstrated that bulleyaconitine A (BLA), an alkaloid from Aconitum bulleyanum, inhibits proliferation and promotes apoptosis of human hepatic Lieming Xu-2 (LX-2) cells. In this study, we analyzed the effect of BLA on the production of ECM and related proteins by LX-2 cells activated with acetaldehyde (AA). The cells were randomized into the control group, AA group (cells activated with 400 μM AA), and BLA+AA group (cells cultured in the presence of 400 μM AA and 18.75 μg/ml BLA). In the BLA+AA group, the contents of collagens I and III and the expression of α-smooth muscle actin and transforming growth factor-β1 (TGF-β1) were statistically significantly higher than in the control, but lower than in the AA group. Expression of MMP-1 in the BLA+AA group was also significantly higher than in the AA group, but lower than in the control. Expression of TIMP-1 in the BLA+AA group was significantly higher than in the control, but lower than in the AA group. Thus, BLA suppressed activation and proliferation of LX-2 cells by inhibiting TGF-β1 signaling pathway and decreasing the content of collagens I and III by reducing the MMP-1/TIMP-1 ratio.

Loss of CEACAM1 in hepatocytes causes hepatic fibrosis

BACKGROUND

The role of insulin resistance in hepatic fibrosis in Metabolic dysfunction-Associated SteatoHepatitis (MASH) remains unclear. Carcinoembryonic Antigen-related Cell Adhesion Molecule1 protein (CEACAM1) promotes insulin clearance to maintain insulin sensitivity and repress de novo lipogenesis, as bolstered by the development of insulin resistance and steatohepatitis in AlbuminCre + Cc1fl/fl mice with liver-specific mouse gene encoding CEACAM1 protein (Ceacam1) deletion. We herein investigated whether these mice also developed hepatic fibrosis and whether hepatic CEACAM1 is reduced in patients with MASH at different fibrosis stages.

METHODS

AlbuminCre + Cc1fl/fl mice were fed a regular or a high-fat diet before their insulin metabolism and action were assessed during IPGTT, and their livers excised for histochemical, immunohistochemical and Western blot analysis. Sirius red staining was used to assess fibrosis, and media transfer was employed to examine whether mutant hepatocytes activated hepatic stellate cells (HSCs). Hepatic CEACAM1 protein levels in patients with varying disease stages were assessed by ELISA.

RESULTS

Hepatocytic deletion of Ceacam1 caused hyperinsulinemia-driven insulin resistance emanating from reduced hepatic insulin clearance. AlbuminCre + Cc1fl/fl livers showed inflammation, fibrosis and hepatic injury, with more advanced bridging and chicken-wire hepatic fibrosis under high-fat conditions. Media transferred from hepatocytes isolated from mutant mice activated control HSCs, likely owing to their elevated endothelin1 content. Interestingly, hepatic CEACAM1 levels were lower in the livers of patients with MASH and declined gradually with advanced fibrosis stage.

CONCLUSIONS

Hepatic CEACAM1 levels declined with progression of MASH in humans. The phenotype of AlbuminCre + Cc1fl/fl mice assigned a key role to CEACAM1 loss from hepatocytes in hepatic fibrosis independently of other liver cells.

Advances in Noninvasive Molecular Imaging Probes for Liver Fibrosis Diagnosis

Liver fibrosis is a wound-healing response to chronic liver injury, which may lead to cirrhosis and cancer. Early-stage fibrosis is reversible, and it is difficult to precisely diagnose with conventional imaging modalities such as magnetic resonance imaging, positron emission tomography, single-photon emission computed tomography, and ultrasound imaging. In contrast, probe-assisted molecular imaging offers a promising noninvasive approach to visualize early fibrosis changes in vivo, thus facilitating early diagnosis and staging liver fibrosis, and even monitoring of the treatment response. Here, the most recent progress in molecular imaging technologies for liver fibrosis is updated. We start by illustrating pathogenesis for liver fibrosis, which includes capillarization of liver sinusoidal endothelial cells, cellular and molecular processes involved in inflammation and fibrogenesis, as well as processes of collagen synthesis, oxidation, and cross-linking. Furthermore, the biological targets used in molecular imaging of liver fibrosis are summarized, which are composed of receptors on hepatic stellate cells, macrophages, and even liver collagen. Notably, the focus is on insights into the advances in imaging modalities developed for liver fibrosis diagnosis and the update in the corresponding contrast agents. In addition, challenges and opportunities for future research and clinical translation of the molecular imaging modalities and the contrast agents are pointed out. We hope that this review would serve as a guide for scientists and students who are interested in liver fibrosis imaging and treatment, and as well expedite the translation of molecular imaging technologies from bench to bedside.

Unique metabolomics characteristics for distinguishing cirrhosis related to different liver diseases: A systematic review and meta-analysis

BACKGROUND AND AIM

Clinical evidence for early identification and diagnosis of liver cirrhosis (LC) caused by different types of liver disease is limited. We investigated this topic through a meta-analysis of quantitative metabolomics.

METHODS

Four databases were searched until October 31, 2022 for studies comparing metabolite levels between patients with different types of liver disease and control individuals. A random-effects model was applied for the meta-analysis.

RESULTS

This study included 55 studies with 8266 clinical participants, covering 348 metabolites. In LC related to drug-induced liver injury (DILI), hepatitis B virus (HBV) infection, and non-alcoholic fatty liver disease (NAFLD), the primary bile acid biosynthesis (taurocholic acid: SMD, 1.08[0.81, 1.35]; P < 0.00001; glycocholic acid: SMD, 1.35[1.07, 1.62]; P < 0.00001; taurochenodeoxycholic acid: SMD, 1.36[0.94, 1.78]; P < 0.00001; glycochenodeoxycholic acid: SMD, 1.49[0.93, 2.06]; P < 0.00001), proline and arginine (l-proline: SMD, 1.06[0.53, 1.58]; P < 0.0001; hydroxyproline: SMD, 0.81[0.30, 1.33]; P = 0.002), and fatty acid biosynthesis (palmitic acid: SMD, 0.44[0.21, 0.67]; P = 0.0002; oleic acid: SMD, 0.46[0.19, 0.73]; P = 0.0008; stearic acid: SMD, 0.37[0.07, 0.68]; P = 0.02) metabolic pathways were significantly altered.

CONCLUSION

We identified key biomarkers and metabolic characteristics for distinguishing and identifying LC related to different types of liver disease, providing a new perspective for early diagnosis, disease monitoring, and precise treatment.

The Role of Macrophage Inhibitory Factor in TAA-Induced Liver Fibrosis in Mice: Modulatory Effects of Betaine

Macrophage inhibitory factor (MIF) is a multipotent cytokine, involved in the inflammatory response to infections or injuries. This study investigates the role of MIF in liver fibrosis and the modulating effect of betaine on MIF in thioacetamide (TAA)-induced liver fibrosis. The wild-type and knockout MIF-/- C57BL/6 mice were divided into the following groups: control; Bet group, which received betaine; MIF-/-; MIF-/-+Bet; TAA group, which received TAA; TAA+Bet; MIF-/-+TAA; and MIF-/-+TAA+Bet group. After eight weeks of treatment, liver tissue was collected for further analysis. The results revealed that TAA-treated MIF-deficient mice had elevated levels of hepatic TGF-β1 and PDGF-BB, as well as MMP-2, MMP-9, and TIMP-1 compared to TAA-treated wild-type mice. However, the administration of betaine to TAA-treated MIF-deficient mice reduced hepatic TGF-β1 and PDGF-BB levels and also the relative activities of MMP-2, MMP-9 and TIMP-1, albeit less effectively than in TAA-treated mice without MIF deficiency. Furthermore, the antifibrogenic effect of MIF was demonstrated by an increase in MMP2/TIMP1 and MMP9/TIMP1 ratios. The changes in the hepatic levels of fibrogenic factors were confirmed by a histological examination of liver tissue. Overall, the dual nature of MIF highlights its involvement in the progression of liver fibrosis. Its prooxidant and proinflammatory effects may exacerbate tissue damage and inflammation initially, but its antifibrogenic activity suggests a potential protective role against fibrosis development. The study showed that betaine modulates the antifibrogenic effects of MIF in TAA-induced liver fibrosis, by decreasing TGF-β1, PDGF-BB, MMP-2, MMP-9, TIMP-1, and the deposition of ECM (Coll1 and Coll3) in the liver.

Direct reprogramming of fibroblasts into functional hepatocytes via CRISPRa activation of endogenous Gata4 and Foxa3

BACKGROUND

The ability to generate functional hepatocytes without relying on donor liver organs holds significant therapeutic promise in the fields of regenerative medicine and potential liver disease treatments. Clustered regularly interspaced short palindromic repeats (CRISPR) activator (CRISPRa) is a powerful tool that can conveniently and efficiently activate the expression of multiple endogenous genes simultaneously, providing a new strategy for cell fate determination. The main purpose of this study is to explore the feasibility of applying CRISPRa for hepatocyte reprogramming and its application in the treatment of mouse liver fibrosis.

METHOD

The differentiation of mouse embryonic fibroblasts (MEFs) into functional induced hepatocyte-like cells (iHeps) was achieved by utilizing the CRISPRa synergistic activation mediator (SAM) system, which drove the combined expression of three endogenous transcription factors- Gata4, Foxa3 , and Hnf1a -or alternatively, the expression of two transcription factors, Gata4 and Foxa3 . In vivo , we injected adeno-associated virus serotype 6 (AAV6) carrying the CRISPRa SAM system into liver fibrotic Col1a1-CreER ; Cas9fl/fl mice, effectively activating the expression of endogenous Gata4 and Foxa3 in fibroblasts. The endogenous transcriptional activation of genes was confirmed using real-time quantitative polymerase chain reaction (RT-qPCR) and RNA-seq, and the morphology and characteristics of the induced hepatocytes were observed through microscopy. The level of hepatocyte reprogramming in vivo is detected by immunofluorescence staining, while the improvement of liver fibrosis is evaluated through Sirius red staining, alpha-smooth muscle actin (α-SMA) immunofluorescence staining, and blood alanine aminotransferase (ALT) examination.

RESULTS

Activation of only two factors, Gata4 and Foxa3 , via CRISPRa was sufficient to successfully induce the transformation of MEFs into iHeps. These iHeps could be expanded in vitro and displayed functional characteristics similar to those of mature hepatocytes, such as drug metabolism and glycogen storage. Additionally, AAV6-based delivery of the CRISPRa SAM system effectively induced the hepatic reprogramming from fibroblasts in mice with live fibrosis. After 8 weeks of induction, the reprogrammed hepatocytes comprised 0.87% of the total hepatocyte population in the mice, significantly reducing liver fibrosis.

CONCLUSION

CRISPRa-induced hepatocyte reprogramming may be a promising strategy for generating functional hepatocytes and treating liver fibrosis caused by hepatic diseases.

miR-92a-3p promotes pulmonary fibrosis progression by regulating KLF2-mediated endothelial-to-mesenchymal transition

Pulmonary fibrosis (PF) is a chronic lung disease that has a poor prognosis and a serious impact on the quality of life of patients. Here, we investigated the potential role of miR-92a-3p in PF. The mRNA level of miR-92a-3p was significantly increased in both the lung tissues of bleomycin (BLM)--treated mice and pulmonary microvascular endothelial cells (PMVECs). Overexpressing miR-92a-3p increased the mRNA and protein levels of α‑SMA, vimentin, and Col-1 but downregulated E-cadherin. Additionally, the protein and mRNA expression levels of KLF2 were significantly decreased in the lung tissues of BLM-treated mice, suggesting that KLF2 participated in the progression of BLM-induced PF. Downregulating miR-92a-3p upregulated the expression of KLF2 and inhibited the endothelial-to-mesenchymal transition (EndoMT) process, thus alleviating PF in vivo. Altogether, a miR-92a-3p deficiency could significantly reduce the development of myofibroblasts and ameliorate PF progression.

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.

The α-1 Adrenergic Receptor Antagonist Doxazosin Attenuates Liver Fibrosis by Alleviating Sinusoidal Capillarization and Liver Angiogenesis

Liver fibrosis and cirrhosis, which are caused by chronic liver injury, represent common and intractable clinical challenges of global importance. However, effective therapeutics are lacking. Therefore, the study examines the effect of doxazosin on liver fibrosis. Carbon tetrachloride (CCl4) is injected into mice to establish a liver fibrosis model. Doxazosin (5 and 10 mg/kg) is administered daily by gavage. HE staining, Masson staining, Sirius Red staining, scanning electron microscopy, western blotting, real-time PCR, and immunofluorescence analysis are performed to estimate liver fibrosis and sinusoidal capillarization in mice. Cell Counting Kit-8 assays, western blotting, immunofluorescence analysis, tube formation, and transwell migration assays are performed on human umbilical vein endothelial cells (HUVECs) and human hepatic sinusoidal endothelial cells (HHSECs) to elucidate the potential mechanism of doxazosin. Doxazosin alleviates liver fibrosis and sinusoidal capillarization in CCl4-induced mice. Angiogenesis is attenuated by doxazosin in HUVECs and HHSECs. This study demonstrates that doxazosin attenuated liver fibrosis by alleviating sinusoidal capillarization and liver angiogenesis.

A comparative study of three ultrasound techniques for liver fibrosis staging

The aim of this study is to assess the agreement and performance of visual transient elastography (ViTE), sound touch elastography (STE), and sound touch quantification (STQ) for liver fibrosis staging using transient elastography (TE) as a standard. We finally enrolled 252 subjects with chronic liver disease (CLD) who underwent ViTE, STE, STQ, and TE examinations simultaneously in our hospital from October 2022 to July 2023. We evaluated the correlation and agreement between various technologies. And also evaluated the performances and optimal cutoffs of ViTE, STE, and STQ . The correlation coefficients of ViTE and TE, STE and TE, STQ and TE were 0.863, 0.709, and 0.727, respectively. The ICC among ViTE, STE, STQ, and TE was 0.911. The area under the receiver operating characteristics (AUROCs) of ViTE, STE, and STQ for detection of TE of ≥5 kPa, ≥10 kPa, ≥15 kPa, and ≥20 kPa were 0.867, 0.771, 0.804; 0.972, 0.935, 0.933; 0.998, 0.973, 0.968; and 1.000, 0.960, 0.954, respectively. The AUROCs of ViTE for detection of lower stages (TE≥5 kPa and ≥10 kPa) were significantly higher than STE and STQ in the overall cohort (ViTE vs. STE: Z  = 2.766, for TE ≥5 kPa; ViTE vs. STE: Z  = 2.145, ; ViTE vs. STQ: Z  = 2.587, for TE ≥10 kPa) (all P < 0.05). These methods all have coincided with performance in more advanced stages (TE ≥15 kPa and ≥20 kPa) (all P  > 0.05). These methods showed excellent correlation and agreement. ViTE performance in more advanced fibrosis differentiation is comparable to the STE and STQ while ViTE is more accurate than STE and STQ to identify patients with mild CLD stage, and can more effectively rule out compensated advanced CLD.

Immune signature and therapeutic approach of natural killer cell in chronic liver disease and hepatocellular carcinoma

Natural killer (NK) cells are one of the key members of innate immunity that predominantly reside in the liver, potentiating immune responses against viral infections or malignant tumors. It has been reported that changes in cell numbers and function of NK cells are associated with the development and progression of chronic liver diseases (CLDs) including non-alcoholic fatty liver disease, alcoholic liver disease, and chronic viral hepatitis. Also, it is known that the crosstalk between NK cells and hepatic stellate cells plays an important role in liver fibrosis and cirrhosis. In particular, the impaired functions of NK cells observed in CLDs consequently contribute to occurrence and progression of hepatocellular carcinoma (HCC). Chronic infections by hepatitis B or C viruses counteract the anti-tumor immunity of the host by producing the sheddases. Soluble major histocompatibility complex class I polypeptide-related sequence A (sMICA), released from the cell surfaces by sheddases, disrupts the interaction and affects the function of NK cells. Recently, the MICA/B-NK stimulatory receptor NK group 2 member D (NKG2D) axis has been extensively studied in HCC. HCC patients with low membrane-bound MICA or high sMICA concentration have been associated with poor prognosis. Therefore, reversing the sMICA-mediated downregulation of NKG2D has been proposed as an attractive strategy to enhance both innate and adaptive immune responses against HCC. This review aims to summarize recent studies on NK cell immune signatures and its roles in CLD and hepatocellular carcinogenesis and discusses the therapeutic approaches of MICA/B-NKG2D-based or NK cell-based immunotherapy for HCC.

The Effect of Menopausal Status, Insulin Resistance and Body Mass Index on the Prevalence of Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is common and presents in a large proportion-up to 30%-of the global adult female population. Several factors have been linked with NAFLD in women, such as age, obesity, and metabolic syndrome. To extract appropriate details about the topic, we conducted an extensive search using various medical subject headings and entry terms including 'Menopause', 'Non-alcoholic fatty liver disease', 'Insulin resistance', and 'BMI'. This exhaustive search resulted in a total of 180 studies, among which only 19 were able to meet the inclusion criteria. While most of these studies indicated a significant rise in NAFLD prevalence among postmenopausal women, two did not find strong evidence linking menopause with NAFLD. Moreover, it was observed that women with NAFLD had higher insulin resistance levels and BMIs compared to those without the condition. In summary, it is important to consider specific factors like risk profile, hormonal status, and age along with metabolic components when treating women presenting with NAFLD. There is need for data-driven research on how gender affects the sensitivity of biomarkers towards NAFLD as well as the development of sex-specific prediction models-this would help personalize management approaches for women, who stand to benefit greatly from such tailored interventions.

Fluorescence imaging sheds light on the immune evasion mechanisms of hepatic stellate cells mediated by superoxide anion

Whether and how the reactive oxygen species generated by hepatic stellate cells (HSCs) promote immune evasion of hepatocellular carcinoma (HCC) remains mysterious. Therefore, investigating the function of superoxide anion (O2•-), the firstly generated reactive oxygen species, during the immune evasion become necessary. In this work, we establish a novel in situ imaging method for visualization of O2•- changes in HSCs based on a new two-photon fluorescence probe TPH. TPH comprises recognition group for O2•- and HSCs targeting peptides. We observe that O2•- in HSCs gradually rose, impairing the infiltration of CD8+ T cells in HCC mice. Further studies reveal that the cyclin-dependent kinase 4 is deactivated by O2•-, and then cause the up-regulation of PD-L1. Our work provides molecular insights into HSC-mediated immune evasion of HCC, which may represent potential targets for HCC immunotherapy.

Natural killer group 2D-major histocompatibility complex class I polypeptide-related sequence A activation enhances natural killer cell-mediated immunity against hepatocellular carcinoma: A review

The recent clinical introduction of immune checkpoint inhibitors has improved therapeutic outcomes in patients with advanced hepatocellular carcinoma. However, these therapies targeting CD8+ T lymphocytes have a response rate of approximately 30%. In addition to CD8+ T lymphocytes, natural killer (NK) cells represent promising therapeutic targets for hepatocellular carcinoma, because they comprise 30%-50% of all lymphocytes in the liver and contribute to antitumor immunity. A recent meta-analysis revealed that the percentage of infiltrating NK cells in hepatocellular carcinoma correlates with a better patient outcome. Similarly, our previous genome-wide association study on chronic viral hepatitis showed that a single-nucleotide polymorphism of major histocompatibility complex class I polypeptide-related sequence A (MICA), a ligand to the NK activating receptor, plays a critical role in hepatocarcinogenesis. In this review, we summarize the mechanisms underlying the regulation of MICA and NK group 2D expression in chronic hepatitis. Furthermore, we describe recent reports on MICA single-nucleotide polymorphism-driven hepatocarcinogenesis. The suppression of MICA shedding could represent a promising approach for immunosurveillance, as increased expression of membrane-bound MICA achieved through the use of a MICA shedding inhibitor also enhances NK cell-mediated cytotoxicity.

Autophagy and the unfolded protein response shape the non-alcoholic fatty liver landscape: decoding the labyrinth

The incidence of nonalcoholic fatty liver disease (NAFLD) is on the rise, mirroring a global surge in diabetes and metabolic syndrome, as its major leading causes. NAFLD represents a spectrum of liver disorders, ranging from nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH), which can potentially progress to cirrhosis and hepatocellular carcinoma (HCC). Mechanistically, we know the unfolded protein response (UPR) as a protective cellular mechanism, being triggered under circumstances of endoplasmic reticulum (ER) stress. The hepatic UPR is turned on in a broad spectrum of liver diseases, including NAFLD. Recent data also defines molecular mechanisms that may underlie the existing correlation between UPR activation and NAFLD. More interestingly, subsequent studies have demonstrated an additional mechanism, i.e. autophagy, to be involved in hepatic steatosis, and thus NAFLD pathogenesis, principally by regulating the insulin sensitivity, hepatocellular injury, innate immunity, fibrosis, and carcinogenesis. All these findings suggest possible mechanistic roles for autophagy in the progression of NAFLD and its complications. Both UPR and autophagy are dynamic and interconnected fluxes that act as protective responses to minimize the harmful effects of hepatic lipid accumulation, as well as the ER stress during NAFLD. The functions of UPR and autophagy in the liver, together with findings of decreased hepatic autophagy in correlation with conditions that predispose to NAFLD, such as obesity and aging, suggest that autophagy and UPR, alone or combined, may be novel therapeutic targets against the disease. In this review, we discuss the current evidence on the interplay between autophagy and the UPR in connection to the NAFLD pathogenesis.

Potential Hepatoprotective Effects of Allicin on Carbon Tetrachloride-Induced Acute Liver Injury in Mice by Inhibiting Oxidative Stress, Inflammation, and Apoptosis

The global burden of liver disease is enormous, which highlights the need for effective hepatoprotective agents. It was reported that allicin exhibits protective effects against a range of diseases. In this study, we further evaluated allicin's effect and mechanism in acute hepatic injury. Liver injury in mice was induced by intraperitoneal injection with 1% CCl4 (10 mL/kg/day). When the first dose was given, CCl4 was given immediately after administration of different doses of allicin (40, 20, and 10 mg/kg/day) as well as compound glycyrrhizin (CGI, 80 mg/kg/day), and then different doses of allicin (40, 20, and 10 mg/kg/day) as well as compound glycyrrhizin (CGI, 80 mg/kg/day) were administrated every 12 h. The animals were dissected 24 h after the first administration. The findings demonstrated a significant inhibition of CCl4-induced acute liver injury following allicin treatment. This inhibition was evidenced by notable reductions in serum levels of transaminases, specifically aspartate transaminase, along with mitigated histological damage to the liver. In this protective process, allicin plays the role of reducing the amounts or the expression levels of proinflammatory cytokines, IL-1β, IL-6. Furthermore, allicin recovered the activities of the antioxidant enzyme catalase (CAT) and reduced the production of malondialdehyde (MDA) in a dose-dependent manner, and also reduced liver Caspase 3, Caspase 8, and BAX to inhibit liver cell apoptosis. Further analysis showed that the administration of allicin inhibited the increased protein levels of Nuclear factor-erythroid 2-related factor 2 (Nrf2) and NAD(P)H:quinone oxidoreductase 1 (NQO1), which is related to inflammation and oxidative stress. The in vitro study of the LPS-induced RAW264.7 inflammatory cell model confirmed that allicin can inhibit important inflammation-related factors and alleviate inflammation. This research firstly clarified that allicin has a significant protective effect on CCl4-induced liver injury via inhibiting the inflammatory response and hepatocyte apoptosis, alleviating oxidative stress associated with the progress of liver damage, highlighting the potential of allicin as a hepatoprotective agent.

Supplementation of Micro- and Macronutrients-A Role of Nutritional Status in Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is a condition in which the pathological cumulation of fat with coexisting inflammation and damage of hepatic cells leads to progressive dysfunctions of the liver. Except for the commonly well-known major causes of NAFLD such as obesity, dyslipidemia, insulin resistance, or diabetes, an unbalanced diet and imbalanced nutritional status should also be taken into consideration. In this narrative review, we summarized the current knowledge regarding the micro- and macronutrient status of patients suffering from NAFLD considering various diets and supplementation of chosen supplements. We aimed to summarize the knowledge indicating which nutritional impairments may be associated with the onset and progression of NAFLD at the same time evaluating the potential therapy targets that could facilitate the healing process. Except for the above-mentioned objectives, one of the most important aspects of this review was to highlight the possible strategies for taking care of NAFLD patients taking into account the challenges and opportunities associated with the micronutrient status of the patients. The current research indicates that a supplementation of chosen vitamins (e.g., vitamin A, B complex, C, or D) as well as chosen elements such as zinc may alleviate the symptoms of NAFLD. However, there is still a lack of sufficient data regarding healthy ranges of dosages; thus, further research is of high importance in this matter.

DCDC2 inhibits hepatic stellate cell activation and ameliorates CCl4-induced liver fibrosis by suppressing Wnt/β-catenin signaling

Liver fibrosis, as a consequence of chronic liver disease, involves the activation of hepatic stellate cell (HSC) caused by various chronic liver injuries. Emerging evidence suggests that activation of HSC during an inflammatory state can lead to abnormal accumulation of extracellular matrix (ECM). Investigating novel strategies to inhibit HSC activation and proliferation holds significant importance for the treatment of liver fibrosis. As a member of the doublecortin domain-containing family, doublecortin domain containing 2 (DCDC2) mutations can lead to neonatal sclerosing cholangitis, but its involvement in liver fibrosis remains unclear. Therefore, this study aims to elucidate the role of DCDC2 in liver fibrosis. Our findings revealed a reduction in DCDC2 expression in both human fibrotic liver tissues and carbon tetrachloride (CCl4)-induced mouse liver fibrotic tissues. Furthermore, exposure to transforming growth factor beta-1(TGF-β1) stimulation resulted in a dose- and time-dependent decrease in DCDC2 expression. The overexpression of DCDC2 inhibited the expression of α-smooth muscle actin (α-SMA) and type I collagen alpha 1 (Col1α1), and reduced the activation of HSC stimulated with TGF-β1. Additionally, we provided evidence that the Wnt/β-catenin signaling pathway was involved in this process, wherein DCDC2 was observed to inhibit β-catenin activation, thereby preventing its nuclear translocation. Furthermore, our findings demonstrated that DCDC2 could attenuate the proliferation and epithelial-mesenchymal transition (EMT)-like processes of HSC. In vivo, exogenous DCDC2 could ameliorate CCl4-induced liver fibrosis. In summary, DCDC2 was remarkably downregulated in liver fibrotic tissues of both humans and mice, as well as in TGF-β1-activated HSC. DCDC2 inhibited the activation of HSC induced by TGF-β1 in vitro and fibrogenic changes in vivo, suggesting that it is a promising therapeutic target for liver fibrosis and warrants further investigation in clinical practice.

Advances in the study of the interaction between schistosome infections and the host's intestinal microorganisms

Schistosomiasis, also called bilharziasis, is a neglected tropical disease induced by schistosomes that infects hundreds of millions of people worldwide. In the life cycle of schistosomiasis, eggs are regarded as the main pathogenic factor, causing granuloma formation in the tissues and organs of hosts, which can cause severe gastrointestinal and liver granulomatous immune responses and irreversible fibrosis. Increasing evidence suggests that the gut microbiome influences the progression of schistosomiasis and plays a central role in liver disease via the gut-liver axis. When used as pharmaceutical supplements or adjunctive therapy, probiotics have shown promising results in preventing, mitigating, and even treating schistosomiasis. This review elucidates the potential mechanisms of this three-way parasite-host-microbiome interaction by summarizing schistosome-mediated intestinal flora disorders, local immune changes, and host metabolic changes, and elaborates the important role of the gut microbiome in liver disease after schistosome infection through the gut-liver axis. Understanding the mechanisms behind this interaction may aid in the discovery of probiotics as novel therapeutic targets and sustainable control strategies for schistosomiasis.

Antagonizing Activin A/p15INK4b Signaling as Therapeutic Strategy for Liver Disease

BACKGROUND/AIM

Activin A is involved in the pathogenesis of human liver diseases, but its therapeutic targeting is not fully explored. Here, we tested the effect of novel, highly specific small-molecule-based activin A antagonists (NUCC-474/555) in improving liver regeneration following partial hepatectomy and halting fibrosis progression in models of chronic liver diseases (CLDs).

METHODS

Cell toxicity of antagonists was determined in rat hepatocytes and Huh-7 cells using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay. Hepatocytes and hepatic stellate cells (HSCs) were treated with activin A and NUCC-555 and analyzed by reverse transcription-polymerase chain reaction and immunohistochemistry. Partial hepatectomized Fisher (F)344 rats were treated with NUCC-555, and bromodeoxyuridine (BrdU) incorporation was determined at 18/24/36/120/240 h. NUCC-555 was administered into thioacetamide- or carbon tetrachloride-treated F344 rats or C57BL/6 mice, and the fibrosis progression was studied.

RESULTS

NUCC-474 showed higher cytotoxicity in cultured hepatic cells; therefore, NUCC-555 was used in subsequent studies. Activin A-stimulated overexpression of cell cycle-/senescence-related genes (e.g., p15INK4b, DEC1, Glb1) was near-completely reversed by NUCC-555 in hepatocytes. Activin A-mediated HSC activation was blocked by NUCC-555. In partial hepatectomized rats, antagonizing activin A signaling resulted in a 1.9-fold and 2.3-fold increase in BrdU+ cells at 18 and 24 h, respectively. Administration of NUCC-555 in rats and mice with progressing fibrosis significantly reduced collagen accumulation (7.9-fold), HSC activation indicated by reduced alpha smooth muscle actin+ and vimentin+ cells, and serum aminotransferase activity.

CONCLUSIONS

Our studies demonstrate that activin A antagonist NUCC-555 promotes liver regeneration and halts fibrosis progression in CLD models, suggesting that blocking activin A signaling may represent a new approach to treating people with CLD.

Conditional deletion of CEACAM1 causes hepatic stellate cell activation

Objectives

Hepatic CEACAM1 expression declines with advanced hepatic fibrosis stage in patients with MASH. Global and hepatocyte-specific deletions of Ceacam1 impair insulin clearance to cause hepatic insulin resistance and steatosis. They also cause hepatic inflammation and fibrosis, a condition characterized by excessive collagen production from activated hepatic stellate cells (HSCs). Given the positive effect of PPARγ on CEACAM1 transcriptoin and on HSCs quiescence, the current studies investigated whether CEACAM1 loss from HSCs causes their activation.

Methods

We examined whether lentiviral shRNA-mediated CEACAM1 donwregulation (KD-LX2) activates cultured human LX2 stellate cells. We also generated LratCre+Cc1 fl/fl mutants with conditional Ceacam1 deletion in HSCs and characterized their MASH phenotype. Media transfer experiments were employed to examine whether media from mutant human and murine HSCs activate their wild-type counterparts.

Results

LratCre+Cc1 fl/fl mutants displayed hepatic inflammation and fibrosis but without insulin resistance or hepatic steatosis. Their HSCs, like KD-LX2 cells, underwent myofibroblastic transformation and their media activated wild-type HDCs. This was inhibited by nicotinic acid treatment which stemmed the release of IL-6 and fatty acids, both of which activate the epidermal growth factor receptor (EGFR) tyrosine kinase. Gefitinib inhibition of EGFR and its downstream NF-κB/IL-6/STAT3 inflammatory and MAPK-proliferation pathways also blunted HSCs activation in the absence of CEACAM1.

Conclusions

Loss of CEACAM1 in HSCs provoked their myofibroblastic transformation in the absence of insulin resistance and hepatic steatosis. This response is mediated by autocrine HSCs activation of the EGFR pathway that amplifies inflammation and proliferation.

Notoginsenoside R1 targets PPAR-γ to inhibit hepatic stellate cell activation and ameliorates liver fibrosis

BACKGROUND

Hepatic fibrosis, a common pathological process that occurs in end-stage liver diseases, is a serious public health problem and lacks effective therapy. Notoginsenoside R1 (NR1) is a small molecule derived from the traditional Chinese medicine Sanqi, exhibiting great potential in treating diverse metabolie disorders. Here we aimed to enquired the role of NR1 in liver fibrosis and its underlying mechanism in hepatoprotective effects.

METHODS

We investigated the anti-fibrosis effect of NR1 using CCl4-induced mouse mode of liver fibrosis as well as TGF-β1-activated JS-1, LX-2 cells and primary hepatic stellate cell. Cell samples treated by NR1 were collected for transcriptomic profiling analysis. PPAR-γ mediated TGF-β1/Smads signaling was examined using PPAR-γ selective inhibitors and agonists intervention, immunofluorescence staining and western blot analysis. Additionally, we designed and studied the binding of NR1 to PPAR-γ using molecular docking.

RESULTS

NR1 obviously attenuated liver histological damage, reduced serum ALT, AST levels, and decreased liver fibrogenesis markers in mouse mode. Mechanistically, NR1 elevated PPAR-γ and decreased TGF-β1, p-Smad2/3 expression. The TGF-β1/Smads signaling pathway and fibrotic phenotype were altered in JS-1 cells after using PPAR-γ selective inhibitors and agonists respectively, confirming PPAR-γ played a pivotal protection role inNR1 treating liver fibrosis. Further molecular docking indicated NR1 had a strong binding tendency to PPAR-γ with minimum free energy.

CONCLUSIONS

NR1 attenuates hepatic stellate cell activation and hepatic fibrosis by elevating PPAR-γ to inhibit TGF-β1/Smads signalling. NR1 may be a potential candidate compound for reliving liver fibrosis.

Sevelamer reverses liver fibrosis by deactivation of hepatic stellate cells

Liver fibrosis is a chronic liver disease characterized by a progressive wound healing response caused by chronic liver injury. Currently, there are no approved clinical treatments for liver fibrosis. Sevelamer is used clinically to treat hyperphosphatemia and has shown potential therapeutic effects on liver diseases. However, there have been few studies evaluating the therapeutic effects of sevelamer on liver fibrosis, and the specific mechanisms are still unclear. In this study, we investigated the antifibrotic effects of sevelamer-induced low inorganic phosphate (Pi) stress in vitro and in vivo and analyzed the detailed mechanisms. We found that low Pi stress could inhibit the proliferation of activated hepatic stellate cells (HSCs) by promoting apoptosis, effectively suppressing the migration and epithelial-mesenchymal transition (EMT) of hepatic stellate cells. Additionally, low Pi stress significantly increased the antioxidant stress response. It is worth noting that low Pi stress indirectly inhibited the activation and migration of HSCs by suppressing transforming growth factor β (TGF-β) expression in macrophages. In a rat model of liver fibrosis, oral administration of sevelamer significantly decreased blood phosphorus levels, improved liver function, reduced liver inflammation, and increased the antioxidant stress response in the liver. Our study revealed that the key mechanism by which sevelamer inhibited liver fibrosis involved binding to gastrointestinal phosphate, resulting in a decrease in blood phosphorus levels, the downregulation of TGF-β expression in macrophages, and the inhibition of HSC migration and fibrosis-related protein expression. Therefore, our results suggest that sevelamer-induced low Pi stress can attenuate hepatic stellate cell activation and inhibit the progression of liver fibrosis, making it a potential option for the treatment of liver fibrosis and other refractory chronic liver diseases.

Sja-let-7 suppresses the development of liver fibrosis via Schistosoma japonicum extracellular vesicles

Schistosomiasis is a fatal zoonotic parasitic disease that also threatens human health. The main pathological features of schistosomiasis are granulomatous inflammation and subsequent liver fibrosis, which is a complex, chronic, and progressive disease. Extracellular vesicles (EVs) derived from schistosome eggs are broadly involved in host-parasite communication and act as important contributors to schistosome-induced liver fibrosis. However, it remains unclear whether substances secreted by the EVs of Schistosoma japonicum, a long-term parasitic "partner" in the hepatic portal vein of the host, also participate in liver fibrosis. Here, we report that EVs derived from S. japonicum worms attenuated liver fibrosis by delivering sja-let-7 into hepatic stellate cells (HSCs). Mechanistically, activation of HSCs was reduced by targeting collagen type I alpha 2 chain (Col1α2) and downregulation of the TGF-β/Smad signaling pathway both in vivo and in vitro. Overall, these results contribute to further understanding of the molecular mechanisms underlying host-parasite interactions and identified the sja-let-7/Col1α2/TGF-β/Smad axis as a potential target for treatment of schistosomiasis-related liver fibrosis.

JCAD deficiency attenuates activation of hepatic stellate cells and cholestatic fibrosis

BACKGROUND/AIMS

Cholestatic liver diseases including primary biliary cholangitis (PBC) are associated with active hepatic fibrogenesis, which ultimately progresses to cirrhosis. Activated hepatic stellate cells (HSCs) are the main fibrogenic effectors in response to cholangiocyte damage. JCAD regulates cell proliferation and malignant transformation in nonalcoholic steatoheaptitis-associated hepatocellular carcinoma (NASH-HCC). However, its participation in cholestatic fibrosis has not been explored yet.

METHODS

Serial sections of liver tissue of PBC patients were stained with immunofluorescence. Hepatic fibrosis was induced by bile duct ligation (BDL) in wild-type (WT), global JCAD knockout mice (JCAD-KO) and HSC-specific JCAD knockout mice (HSC-JCAD-KO), and evaluated by histopathology and biochemical tests. In situ-activated HSCs isolated from BDL mice were used to determine effects of JCAD on HSC activation.

RESULTS

In consistence with staining of liver sections from PBC patients, immunofluorescent staining revealed that JCAD expression was identified in smooth muscle α-actin (α-SMA)-positive fibroblast-like cells and was significantly up-regulated in WT mice with BDL. JCAD deficiency remarkably ameliorated BDL-induced hepatic injury and fibrosis, as documented by liver hydroxyproline content, when compared to WT mice with BDL. Histopathologically, collagen deposition was dramatically reduced in both JCAD-KO and HSC-JCAD-KO mice compared to WT mice, as visualized by Trichrome staining and semi-quantitative scores. Moreover, JCAD deprivation significantly attenuated in situ HSC activation and reduced expression of fibrotic genes after BDL.

CONCLUSION

JCAD deficiency effectively suppressed hepatic fibrosis induced by BDL in mice, and the underlying mechanisms are largely through suppressed Hippo-YAP signaling activity in HSCs.

The role of PI3k/AKT signaling pathway in attenuating liver fibrosis: a comprehensive review

Excessive accumulation of extracellular matrix (ECM) components within the liver leads to a pathological condition known as liver fibrosis. Alcohol abuse, non-alcoholic fatty liver disease (NAFLD), autoimmune issues, and viral hepatitis cause chronic liver injury. Exploring potential therapeutic targets and understanding the molecular mechanisms involved in liver fibrosis are essential for the development of effective interventions. The goal of this comprehensive review is to explain how the PI3K/AKT signaling pathway contributes to the reduction of liver fibrosis. The potential of this pathway as a therapeutic target is investigated through a summary of results from in vivo and in vitro studies. Studies focusing on PI3K/AKT activation have shown a significant decrease in fibrosis markers and a significant improvement in liver function. The review emphasizes how this pathway may prevent ECM synthesis and hepatic stellate cell (HSC) activation, ultimately reducing the fibrotic response. The specific mechanisms and downstream effectors of the PI3K/AKT pathway in liver fibrosis constitute a rapidly developing field of study. In conclusion, the PI3K/AKT signaling pathway plays a significant role in attenuating liver fibrosis. Its complex role in regulating HSC activation and ECM production, demonstrated both in vitro and in vivo, underscores its potential as a effective therapeutic approach for managing liver fibrosis and slowing disease progression. A comprehensive review of this field provides valuable insights into its future developments and implications for clinical applications.

Trans-2-nonadecyl-4-(hydroxymethyl)-1,3-dioxolane (TNHD) purified from freshwater clams markedly alleviates dimethylnitrosamine-induced hepatic fibrosis

Liver fibrosis occurs due to injury or inflammation, which results in the excessive production of collagen and the formation of fibrotic scar tissue that impairs liver function. Despite the limited treatment options available, freshwater clams may hold promise in the treatment of liver fibrosis. In this study, we demonstrated the effects of ethanol extract of freshwater clam (FCE), ethyl acetate extract of FCE (EA-FCE), and trans-2-nonadecyl-4-(hydroxymethyl)-1,3-dioxolane (TNHD) on liver fibrosis induced by dimethylnitrosamine (DMN). Administration of FCE and TNHD alleviated liver injury, including tissue damage, necrosis, inflammation scores, fibrosis scores, serum enzymes, and triglyceride levels. Furthermore, we analyzed the expression of fibrosis-related proteins, such as α-smooth muscle actin (α-SMA) and transforming growth factor (TGF-β), as well as the hydroxyproline content, which decreased after treatment with FCE and TNHD. Animal experiments revealed that FCE and TNHD can reduce liver fibrosis by inhibiting cytokines that activate stellate cells and decreasing extracellular matrix (ECM) secretion. Cell experiments have shown that TNHD inhibits the MAPK/Smad signaling pathway and TGF-β1 activation, resulting in a reduction in the expression of fibrosis-related proteins. Therefore, freshwater clam extracts, particularly TNHD, may have potential therapeutic and preventive effects for the amelioration of liver fibrosis.

An RORα agonist, ODH-08, inhibits fibrogenic activation of hepatic stellate cells via suppression of SMAD3

AIMS

Hepatic fibrosis is a dynamic process characterized by the net accumulation of an extracellular matrix resulting from chronic liver injury such as nonalcoholic steatohepatitis. Activation of hepatic stellate cells (HSCs) plays a role in transdifferentiation of quiescent cells into fibrogenic myofibroblasts. We aimed to examine the function of retinoic acid receptor-related orphan receptor alpha (RORα) and its novel agonistic ligand, 1-(4-benzyloxybenzyl)-3-(2-dimethylaminoethyl)-thiourea (ODH-08) against activation of HSCs using hepatic fibrosis mouse models.

MAIN METHODS

Chemical synthesis, a reporter gene assay, surface plasmon resonance analysis, and a docking study were performed to evaluate ODH-08 as a ligand of RORα. In vivo experiments with mice fed a Western diet were performed to evaluate the effect of ODH-08. The human HSC line, Lx-2, and primary mouse HSCs were employed to identify the molecular mechanisms underlying the antifibrogenic effect of ODH-08.

KEY FINDINGS

A novel RORα-selective ligand, ODH-08, was developed based on modification of JC1-40, an analog of N-methylthiourea. Administration of ODH-08 to the Western diet-fed mice reduced hepatic collagen deposition and expression levels of fibrogenic markers such as α-smooth muscle actin and collagen type I alpha 1 chain. Activation of RORα-either by transient overexpression of RORα or treatment with ODH-08-suppressed the expression of fibrogenic proteins in HSCs. The activation of RORα suppressed the activity of SMAD2 and 3, which are the primary downstream proteins of transforming growth factor β.

SIGNIFICANCE

RORα and its agonist ODH-08 have a potent antifibrotic effect, which could provide a novel antifibrotic strategy against hepatic fibrosis.

Metabolic disorders affecting the liver and heart: Therapeutic efficacy of miRNA-based therapies?

Liver and heart disease are major causes of death worldwide. It is known that metabolic alteration causing type 2 diabetes (T2D) and Nonalcoholic fatty liver (NAFLD) coupled with a derangement in lipid homeostasis, may exacerbate hepatic and cardiovascular diseases. Some pharmacological treatments can mitigate organ dysfunctions but the important side effects limit their efficacy leading often to deterioration of the tissues. It needs to develop new personalized treatment approaches and recent progresses of engineered RNA molecules are becoming increasingly viable as alternative treatments. This review outlines the current use of antisense oligonucleotides (ASOs), RNA interference (RNAi) and RNA genome editing as treatment for rare metabolic disorders. However, the potential for small non-coding RNAs to serve as therapeutic agents for liver and heart diseases is yet to be fully explored. Although miRNAs are recognized as biomarkers for many diseases, they are also capable of serving as drugs for medical intervention; several clinical trials are testing miRNAs as therapeutics for type 2 diabetes, nonalcoholic fatty liver as well as cardiac diseases. Recent advances in RNA-based therapeutics may potentially facilitate a novel application of miRNAs as agents and as druggable targets. In this work, we sought to summarize the advancement and advantages of miRNA selective therapy when compared to conventional drugs. In particular, we sought to emphasise druggable miRNAs, over ASOs or other RNA therapeutics or conventional drugs. Finally, we sought to address research questions related to efficacy, side-effects, and range of use of RNA therapeutics. Additionally, we covered hurdles and examined recent advances in the use of miRNA-based RNA therapy in metabolic disorders such as diabetes, liver, and heart diseases.

FOXS1 is increased in liver fibrosis and regulates TGFβ responsiveness and proliferation pathways in human hepatic stellate cells

Liver fibrosis commences with liver injury stimulating transforming growth factor beta (TGFβ) activation of hepatic stellate cells (HSCs), causing scarring and irreversible damage. TGFβ induces expression of the transcription factor Forkhead box S1 (FOXS1) in hepatocytes and may have a role in the pathogenesis of hepatocellular carcinoma (HCC). To date, no studies have determined how it affects HSCs. We analyzed human livers with cirrhosis, HCC, and a murine fibrosis model and found that FOXS1 expression is significantly higher in fibrotic livers but not in HCC. Next, we treated human LX2 HSC cells with TGFβ to activate fibrotic pathways, and FOXS1 mRNA was significantly increased. To study TGFβ-FOXS1 signaling, we developed human LX2 FOXS1 CRISPR KO and scrambled control HSCs. To determine differentially expressed gene transcripts controlled by TGFβ-FOXS1, we performed RNA-seq in the FOXS1 KO and control cells and over 400 gene responses were attenuated in the FOXS1 KO HSCs with TGFβ-activation. To validate the RNA-seq findings, we used our state-of-the-art PamGene PamStation kinase activity technology that measures hundreds of signaling pathways nonselectively in real time. Using our RNA-seq data, kinase activity data, and descriptive measurements, we found that FOXS1 controls pathways mediating TGFβ responsiveness, protein translation, and proliferation. Our study is the first to identify that FOXS1 may serve as a biomarker for liver fibrosis and HSC activation, which may help with early detection of hepatic fibrosis or treatment options for end-stage liver disease.

The miR-3074/BMP7 axis regulates TGF-β-caused activation of hepatic stellate cells in vitro and CCl4-caused murine liver fibrosis in vivo

Continuously progressive hepatic fibrosis might cause chronic liver diseases, resulting in hepatic failure. The activation of hepatic stellate cells (HSCs) residing in the liver might induce and influence hepatic fibrosis. In the present study, microRNA 3074 (miR-3074) was found increased within transforming growth factor-β (TGF-β)-activated HSCs and enriched within the TGF-β signaling. In activated HSCs by TGF-β, miR-3074 overexpression aggravated TGF-β-induced fibrotic changes, whereas miR-3074 inhibition exerted opposite effects. miR-3074 directly targeted bone morphogenetic protein 7 (BMP7) and inhibited BMP7 expression. Under TGF-β induction, overexpressed BMP7 notably attenuated the promotive roles of miR-3074 overexpression in TGF-β-activated HSCs. Within carbon tetrachloride (CCl4)-caused liver fibrosis murine model, miR-3074 agomir administration promoted, while LV-BMP7 administration alleviated CCl4-induced fibrotic changes; LV-BMP7 significantly attenuated the effects of miR-3074 agomir. Lastly, mmu-miR-3074 also targeted mouse BMP7 and inhibited mouse BMP7 expression. In conclusion, the miR-3074/BMP7 axis regulates TGF-β-caused activation of HSCs in vitro and CCl4-caused murine liver fibrosis in vivo. BMP7-mediated Smad1/5/8 activation might be involved.

PEI-based functional materials: Fabrication techniques, properties, and biomedical applications

Cationic polymers have recently attracted considerable interest as research breakthroughs for various industrial and biomedical applications. They are particularly interesting due to their highly positive charges, acceptable physicochemical properties, and ability to undergo further modifications, making them attractive candidates for biomedical applications. Polyethyleneimines (PEIs), as the most extensively utilized polymers, are one of the valuable and prominent classes of polycations. Owing to their flexible polymeric chains, broad molecular weight (MW) distribution, and repetitive structural units, their customization for functional composites is more feasible. The specific beneficial attributes of PEIs could be introduced by purposeful functionalization or modification, long service life, biocompatibility, and distinct geometry. Therefore, PEIs have significant potential in biotechnology, medicine, and bioscience. In this review, we present the advances in PEI-based nanomaterials, their transfection efficiency, and their toxicity over the past few years. Furthermore, the potential and suitability of PEIs for various applications are highlighted and discussed in detail. This review aims to inspire readers to investigate innovative approaches for the design and development of next-generation PEI-based nanomaterials possessing cutting-edge functionalities and appealing characteristics.

Therapeutic potential and mechanisms of Rifaximin in ameliorating iron overload-induced ferroptosis and liver fibrosis in vivo and in vitro

Liver fibrosis could progress to liver cirrhosis with several contributing factors, one being iron overload which triggers ferroptosis, a form of regulated cell death. Rifaximin, a non-absorbable antibiotic, has shown promise in mitigating fibrosis, primarily by modulating gut microbiota. This study investigated the effects and mechanisms of rifaximin on iron overload-related hepatic fibrosis and ferroptosis. In an iron overload-induced liver fibrosis model in mice and in ferric ammonium citrate (FAC)-stimulated primary hepatocytes, treatment with rifaximin showed significant therapeutic effects. Specifically, it ameliorated the processes of ferroptosis triggered by iron overload, reduced liver injury, and alleviated fibrosis. This was demonstrated by decreased iron accumulation in the liver, improved liver function, and reduced fibrotic area and collagen deposition. Rifaximin also modulated key proteins related to iron homeostasis and ferroptosis, including reduced expression of TFR1, a protein facilitating cellular iron uptake, and increased expression of Fpn and FTH, proteins involved in iron export and storage. In the context of oxidative stress, rifaximin treatment led to a decrease in lipid peroxidation, evidenced by reduced levels of reactive oxygen species (ROS) and malondialdehyde (MDA), and an increase in the reduced glutathione (GSH) and decrease in oxidized glutathione (GSSG). Notably, rifaximin's potential functions were associated with the TGF-β pathway, evidenced by suppressed Tgfb1 protein levels and ratios of phosphorylated to total Smad2 and Smad3, whereas increased Smad7 phosphorylation. These findings indicate rifaximin's therapeutic potential in managing liver fibrosis by modulating the TGF-β pathway and reducing iron overload-induced damage. Further research is required to confirm these results and explore their clinical implications.

Abnormal metabolism in hepatic stellate cells: Pandora's box of MAFLD related hepatocellular carcinoma

Metabolic associated fatty liver disease (MAFLD) is a significant risk factor for the development of hepatocellular carcinoma (HCC). Hepatic stellate cells (HSCs), as key mediators in liver injury response, are believed to play a crucial role in the repair process of liver injury. However, in MAFLD patients, the normal metabolic and immunoregulatory mechanisms of HSCs become disrupted, leading to disturbances in the local microenvironment. Abnormally activated HSCs are heavily involved in the initiation and progression of HCC. The metabolic disorders and abnormal activation of HSCs not only initiate liver fibrosis but also contribute to carcinogenesis. In this review, we provide an overview of recent research progress on the relationship between the abnormal metabolism of HSCs and the local immune system in the liver, elucidating the mechanisms of immune imbalance caused by abnormally activated HSCs in MAFLD patients. Based on this understanding, we discuss the potential and challenges of metabolic-based and immunology-based mechanisms in the treatment of MAFLD-related HCC, with a specific focus on the role of HSCs in HCC progression and their potential as targets for anti-cancer therapy. This review aims to enhance researchers' understanding of the importance of HSCs in maintaining normal liver function and highlights the significance of HSCs in the progression of MAFLD-related HCC.

Endothelial cells drive organ fibrosis in mice by inducing expression of the transcription factor SOX9

Fibrosis is a hallmark of chronic disease. Although fibroblasts are involved, it is unclear to what extent endothelial cells also might contribute. We detected increased expression of the transcription factor Sox9 in endothelial cells in several different mouse fibrosis models. These models included systolic heart failure induced by pressure overload, diastolic heart failure induced by high-fat diet and nitric oxide synthase inhibition, pulmonary fibrosis induced by bleomycin treatment, and liver fibrosis due to a choline-deficient diet. We also observed up-regulation of endothelial SOX9 in cardiac tissue from patients with heart failure. To test whether SOX9 induction was sufficient to cause disease, we generated mice with endothelial cell-specific overexpression of Sox9, which promoted fibrosis in multiple organs and resulted in signs of heart failure. Endothelial Sox9 deletion prevented fibrosis and organ dysfunction in the two mouse models of heart failure as well as in the lung and liver fibrosis mouse models. Bulk and single-cell RNA sequencing of mouse endothelial cells across multiple vascular beds revealed that SOX9 induced extracellular matrix, growth factor, and inflammatory gene expression, leading to matrix deposition by endothelial cells. Moreover, mouse endothelial cells activated neighboring fibroblasts that then migrated and deposited matrix in response to SOX9, a process partly mediated by the secreted growth factor CCN2, a direct SOX9 target; endothelial cell-specific Sox9 deletion reversed these changes. These findings suggest a role for endothelial SOX9 as a fibrosis-promoting factor in different mouse organs during disease and imply that endothelial cells are an important regulator of fibrosis.

Recent advances in age-related metabolic dysfunction-associated steatotic liver disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) affects approximately 25% of the world's population and has become a leading cause of chronic liver disease. In recent years, an increasing amount of data suggests that MASLD is associated with aging. As the population ages, age-related MASLD will become a major global health problem. Targeting an aging will become a new approach to the treatment of MASLD. This paper reviews the current studies on the role of aging-related factors and therapeutic targets in MASLD, including: Oxidative stress, autophagy, mitochondrial homeostasis, bile acid metabolism homeostasis, and dysbiosis. The aim is to identify effective therapeutic targets for age-related MASLD and its progression.

Endotoxin Inflammatory Action on Cells by Dysregulated-Immunological-Barrier-Linked ROS-Apoptosis Mechanisms in Gut-Liver Axis

Our study highlighted the immune changes by pro-inflammatory biomarkers in the gut-liver-axis-linked ROS-cell death mechanisms in chronic and acute inflammations when gut cells are exposed to endotoxins in patients with hepatic cirrhosis or steatosis. In duodenal tissue samples, gut immune barrier dysfunction was analyzed by pro-inflammatory biomarker expressions, oxidative stress, and cell death by flow cytometry methods. A significant innate and adaptative immune system reaction was observed as result of persistent endotoxin action in gut cells in chronic inflammation tissue samples recovered from hepatic cirrhosis with the A-B child stage. Instead, in patients with C child stage of HC, the endotoxin tolerance was installed in cells, characterized by T lymphocyte silent activation and increased Th1 cytokines expression. Interesting mechanisms of ROS-cell death were observed in chronic and acute inflammation samples when gut cells were exposed to endotoxins and immune changes in the gut-liver axis. Late apoptosis represents the chronic response to injury induction by the gut immune barrier dysfunction, oxidative stress, and liver-dysregulated barrier. Meanwhile, necrosis represents an acute and severe reply to endotoxin action on gut cells when the immune system reacts to pro-inflammatory Th1 and Th2 cytokines releasing, offering protection against PAMPs/DAMPs by monocytes and T lymphocyte activation. Flow cytometric analysis of pro-inflammatory biomarkers linked to oxidative stress-cell death mechanisms shown in our study recommends laboratory techniques in diagnostic fields.

Ablation of DGKα facilitates α-smooth muscle actin expression via the Smad and PKCδ signaling pathways during the acute phase of CCl4 -induced hepatic injury

Expression of α-smooth muscle actin (αSMA) is constitutive in vascular smooth muscle cells, but is induced in nonmuscle cells such as hepatic stellate cells (HSCs). HSCs play important roles in both physiological homeostasis and pathological response. HSC activation is characterized by αSMA expression, which is regulated by the TGFβ-induced Smad pathway. Recently, protein kinase C (PKC) was identified to regulate αSMA expression. Diacylglycerol kinase (DGK) metabolizes a second-messenger DG, thereby controlling components of DG-mediated signaling, such as PKC. In the present study we aimed to investigate the putative role of DGKα in αSMA expression. Use of a cellular model indicated that the DGK inhibitor R59949 promotes αSMA expression and PKCδ phosphorylation. It also facilitates Smad2 phosphorylation after 30 min of TGFβ stimulation. Furthermore, immunocytochemical analysis revealed that DGK inhibitor pretreatment without TGFβ stimulation engenders αSMA expression in a granular pattern, whereas DGK inhibitor pretreatment plus TGFβ stimulation significantly induces αSMA incorporation in stress fibers. Through animal model experiments, we observed that DGKα-knockout mice exhibit increased expression of αSMA in the liver after 48 h of carbon tetrachloride injection, together with enhanced phosphorylation levels of Smad2 and PKCδ. Together, these findings suggest that DGKα negatively regulates αSMA expression by acting on the Smad and PKCδ signaling pathways, which differentially regulate stress fiber incorporation and protein expression of αSMA, respectively.

The polymorphic variant of SerpinB3 (SerpinB3-PD) is associated with faster cirrhosis decompensation

BACKGROUND

SerpinB3 is a cysteine protease inhibitor involved in liver disease progression due to its proinflammatory and profibrogenic properties. The polymorphic variant SerpinB3-PD (SB3-PD), presents a substitution in its reactive centre loop, determining the gain of function.

AIMS

To disclose the clinical characteristics of a cohort of patients with cirrhosis in relation to the presence of SB3-PD and to assess the effect of this genetic variant on fibrogenic and inflammatory cytokines in vitro.

METHODS

We assessed SB3 polymorphism in 90 patients with cirrhosis, prospectively followed up in our referral centre. We used HepG2 and HuH-7 cells transfected to overexpress either wild-type SB3 (SB3-WT) or SB3-PD to assess their endogenous effect, while LX2 and THP-1 cells were treated with exogenous SB3-WT or SB3-PD proteins.

RESULTS

Patients carrying SB3-PD had more severe portal hypertension and higher MELD scores, than patients carrying SB3-WT. In multivariate analysis, SB3-PD was an independent predictor of cirrhosis complications. Patients with SB3-PD polymorphism presented with more severe liver fibrosis and inflammatory features. Hepatoma cells overexpressing SB3-PD showed higher TGF-β1 expression than controls. The addition of recombinant SB3-PD induced an up-regulation of TGF-β1 in LX2 cells and a more prominent inflammatory profile in THP-1 cells, compared to the effect of SB3-WT protein.

CONCLUSIONS

The polymorphic variant SB3-PD is highly effective in determining activation of TGF-β1 and inflammation in vitro. Patients with cirrhosis who carry SB3-PD polymorphism may be more prone to develop severe liver disease progression. However, further validation studies are warranted to support the in vivo relevance of this polymorphism.

HIV-Infected Hepatic Stellate Cells or HCV-Infected Hepatocytes Are Unable to Promote Latency Reversal among HIV-Infected Mononuclear Cells

Due to a common mode of transmission through infected human blood, hepatitis C virus (HCV) and human immunodeficiency virus (HIV) co-infection is relatively prevalent. In alignment with this, HCV co-infection is associated with an increased size of the HIV reservoir in highly active antiretroviral therapy (HAART)-treated individuals. Hence, it is crucial to comprehend the physiological mechanisms governing the latency and reactivation of HIV in reservoirs. Consequently, our study delves into the interplay between HCV/HIV co-infection in liver cells and its impact on the modulation of HIV latency. We utilized the latently infected monocytic cell line (U1) and the latently infected T-cell line (J-Lat) and found that mediators produced by the infection of hepatic stellate cells and hepatocytes with HIV and HCV, respectively, were incapable of inducing latency reversal under the studied conditions. This may favor the maintenance of the HIV reservoir size among latently infected mononuclear cells in the liver. Further investigations are essential to elucidate the role of the interaction between liver cells in regulating HIV latency and/or reactivation, providing a physiologically relevant model for comprehending reservoir microenvironments in vivo.

Tanshinone IIA regulates CCl4 induced liver fibrosis in C57BL/6J mice via the PI3K/Akt and Nrf2/HO-1 signaling pathways

Chronic liver diseases caused by various factors may develop into liver fibrosis (LF). Early stage of LF could be reversible. Tanshinone IIA (Tan IIA), an extract from Salvia miltiorrhiza, has been reported to be hepatoprotective. However, the potential targets and mechanism of Tan IIA in the treatment of LF are still unclear. Our study aims at the anti-LF mechanism of Tan IIA through network pharmacological analysis combined with LF-related experiments. Serum biochemical indicators and histopathological examination showed that Tan IIA could ameliorate the process of LF in the CCl4 -induced mouse model. Western blot and immunohistochemical assays showed that Tan IIA decreased the expression of Kirsten rat sarcoma viral oncogene homolog (KRAS), phosphatidylinositide 3-kinases/protein kinase B (PI3K/Akt), and nuclear factor erythroid 2-related factor/heme oxygenase-1 (Nrf2/HO-1). Compared with the model group, the Tan IIA groups increased the decreased superoxide dismutase activity and glutathione content, while decreasing the increased malondialdehyde content. These results indicate that Tan IIA may play an antioxidant role by inhibiting the expression of KRAS, PI3K/Akt, and Nrf2/HO-1 to ameliorate the progression of LF, which to some extent explains the pharmacological mechanism of Tan IIA in LF. In conclusion, our study demonstrates that Tan IIA could regulate LF via PI3K/Akt and Nrf2/HO-1 signaling pathways. It may be an effective therapeutic compound for the treatment of LF.

Therapeutic potential of melatonin in targeting molecular pathways of organ fibrosis

Fibrosis, the excessive deposition of fibrous connective tissue in an organ in response to injury, is a pathological condition affecting many individuals worldwide. Fibrosis causes the failure of tissue function and is largely irreversible as the disease progresses. Pharmacologic treatment options for organ fibrosis are limited, but studies suggest that antioxidants, particularly melatonin, can aid in preventing and controlling fibrotic damage to the organs. Melatonin, an indole nocturnally released from the pineal gland, is commonly used to regulate circadian and seasonal biological rhythms and is indicated for treating sleep disorders. While it is often effective in treating sleep disorders, melatonin's anti-inflammatory and antioxidant properties also make it a promising molecule for treating other disorders such as organ fibrosis. Melatonin ameliorates the necrotic and apoptotic changes that lead to fibrosis in various organs including the heart, liver, lung, and kidney. Moreover, melatonin reduces the infiltration of inflammatory cells during fibrosis development. This article outlines the protective effects of melatonin against fibrosis, including its safety and potential therapeutic effects. The goal of this article is to provide a summary of data accumulated to date and to encourage further experimentation with melatonin and increase its use as an anti-fibrotic agent in clinical settings.

Prediction of CAF-related genes in immunotherapy and drug sensitivity in hepatocellular carcinoma: a multi-database analysis

This study aims to identify the cancer-associated fibroblasts (CAF)-related genes that can affect immunotherapy and drug sensitivity in hepatocellular carcinoma (HCC). Expression data and survival data associated with HCC were obtained in The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Weighted correlation network analysis (WGCNA) analysis was performed to obtain CAF-related genes. Least Absolute Shrinkage and Selection Operator (LASSO) regression was used for regression analysis and risk models. Subsequently, Gene Set Enrichment Analysis (GSEA) analysis, Gene Set Enrichment Analysis (ssGSEA) analysis, Tumor Immune Dysfunction and Exclusion (TIDE) analysis and drug sensitivity analysis were performed on the risk models. Survival analysis of CAF scores showed that the survival rate was lower in samples with high CAF scores than those with low scores. However, this difference was not significant, suggesting CAF may not directly influence the prognosis of HCC patients. Further screening of CAF-related genes yielded 33 CAF-related genes. Seven risk models constructed based on CDR2L, SPRED1, PFKP, ENG, KLF2, FSCN1 and VCAN, showed significant differences in immunotherapy and partial drug sensitivity in HCC. Seven CAF-related genes may have important roles in immunotherapy, drug sensitivity and prognostic survival in HCC patients.

The occurrence and development mechanisms of esophageal stricture: state of the art review

BACKGROUND

Esophageal strictures significantly impair patient quality of life and present a therapeutic challenge, particularly due to the high recurrence post-ESD/EMR. Current treatments manage symptoms rather than addressing the disease's etiology. This review concentrates on the mechanisms of esophageal stricture formation and recurrence, seeking to highlight areas for potential therapeutic intervention.

METHODS

A literature search was conducted through PUBMED using search terms: esophageal stricture, mucosal resection, submucosal dissection. Relevant articles were identified through manual review with reference lists reviewed for additional articles.

RESULTS

Preclinical studies and data from animal studies suggest that the mechanisms that may lead to esophageal stricture include overdifferentiation of fibroblasts, inflammatory response that is not healed in time, impaired epithelial barrier function, and multimethod factors leading to it. Dysfunction of the epithelial barrier may be the initiating mechanism for esophageal stricture. Achieving perfect in-epithelialization by tissue-engineered fabrication of cell patches has been shown to be effective in the treatment and prevention of esophageal strictures.

CONCLUSION

The development of esophageal stricture involves three stages: structural damage to the esophageal epithelial barrier (EEB), chronic inflammation, and severe fibrosis, in which dysfunction or damage to the EEB is the initiating mechanism leading to esophageal stricture. Re-epithelialization is essential for the treatment and prevention of esophageal stricture. This information will help clinicians or scientists to develop effective techniques to treat esophageal stricture in the future.

The Role of Zinc on Liver Fibrosis by Modulating ZIP14 Expression Throughout Epigenetic Regulatory Mechanisms

Zinc plays a pivotal role in tissue regeneration and maintenance being as a central cofactor in a plethora of enzymatic activities. Hypozincemia is commonly seen with chronic liver disease and is associated with an increased risk of liver fibrosis development and hepatocellular carcinoma. Previously favorable effects of zinc supplementation on liver fibrosis have been shown. However, the underlying mechanism of this effect is not elucidated. Liver fibrosis was induced in mice by using CCl4 injection, followed by treatment with zinc chloride (ZnCl2) both at fibrotic and sham groups, and their hepatocytes were isolated. Our results showed that the administration of ZnCl2 restored the depleted cytosolic zinc levels in the hepatocytes isolated from the fibrotic group. Also, alpha-smooth muscle actin (αSMA) expression in hepatocytes was decreased, indicating a reversal of the fibrotic process. Notably, ZIP14 expression significantly increased in the fibrotic group following ZnCl2 treatment, whereas in the sham group ZIP14 expression decreased. Chromatin immunoprecipitation (ChIP) experiments revealed an increased binding percentage of Metal-regulatory transcription factor 1 (MTF1) on ZIP14 promoter in the hepatocytes isolated from fibrotic mice compared to the sham group after ZnCl2 administration. In the same group, the binding percentage of the histone deacetylase HDAC4 on ZIP14 promoter decreased. Our results suggest that the ZnCl2 treatment ameliorates liver fibrosis by elevating intracellular zinc levels through MTF1-mediated regulation of ZIP14 expression and the reduction of ZIP14 deacetylation via HDAC4. The restoration of intracellular zinc concentrations and the modulation of ZIP14 expression by zinc orchestrated through MTF1 and HDAC4, appear to be essential determinants of the therapeutic response in hepatic fibrosis. These findings pave the way for potential novel interventions targeting zinc-related pathways for the treatment of liver fibrosis and associated conditions.

Baccharis anomala DC. extract reduces inflammation and attenuates hepatic fibrosis in vivo by decreasing NF-kB and extracellular matrix compounds

Baccharis anomala DC. (BA) is a plant species found in the tropical regions of South America and is widely used for its hepatoprotective effects, as well as for the treatment of gastrointestinal diseases. Studies have recently reported its antioxidant and anti-inflammatory potential. BA extract can reverse the activated phenotype of hepatic stellate cells (HSC), which plays a central role in extracellular matrix (ECM) deposition in the development of liver fibrosis. Thus, this study aimed to evaluate the effects of the treatment with BA extract on liver fibrosis in a CCl4-induced liver fibrosis model in BALB/c mice. Methanolic extract was obtained from BA leaves, a gas chromatography/mass spectrometry (GC/MS) to detect the compounds present was performed, and then administered by intraperitoneal injection in Balb/C mice at a concentration of 50 and 100 mg/kg together with the administration of CCl4 for inducing liver fibrosis. After 10 weeks, blood analysis, histopathology, oxidative stress, as well as protein and gene expression in the hepatic tissue were performed. Treatment with BA extract was able to reduce profibrotic markers by reducing the expression of α-SMA and Col-1 proteins, as well as reducing the formation of free radicals and lipid peroxidation. (BA extract showed anti-inflammatory effects in the liver by suppressing NF-kB activation and reducing gene expression of signaling targets (IL-6 and iNOS). The data obtained showed that BA extract has antifibrotic and anti-inflammatory effects.

The Preventive Effect of Endostar on Radiation-induced Pulmonary Fibrosis

BACKGROUND

Radiation-induced pulmonary fibrosis (RIPF) is a long-term complication of thoracic radiotherapy without effective treatment available.

OBJECTIVE

This study aimed to establish a RIPF mouse model and explore the therapeutic effects and mechanisms of recombinant human endostatin (Endostar).

METHODS

C57BL/6 mice received a 16-Gy dose of X-rays to the whole thorax with or without the administration of Endostar for 24 weeks.

RESULTS

Radiation-induced body weight loss was partially attenuated by Endostar (P<0.05). Endostar significantly reduced alveolar inflammation (P<0.05) and pulmonary fibrosis (P<0.001), as indicated by a decrease in the expression levels of collagen I and collagen IV in lung tissue (both P<0.001). Angiogenesis (as shown by CD31 immunohistochemistry) was also decreased (P<0.01). In irradiated mice, Endostar inhibited the transforming growth factor-β1 (TGF-β1)/drosophila mothers against the decapentaplegic 3 (Smad3)/extracellular regulated protein kinases (ERK) signaling pathway (all P<0.05). In vitro, Endostar treatment decreased the radiation-induced expression of TGF-β1, vascular endothelial growth factor (VEGF), p-Smad3, and p-ERK in alveolar epithelial cells and vascular endothelial cells (all P<0.05).

CONCLUSION

Endostar could alleviate RIPF through decreased antiangiogenic activity and inhibition of the TGF-β1/Smad3/ERK pathway.

HDAC9 as a Privileged Target: Reviewing its Role in Different Diseases and Structure-activity Relationships (SARs) of its Inhibitors

HDAC9 is a histone deacetylase enzyme belonging to the class IIa of HDACs which catalyses histone deacetylation. HDAC9 inhibit cell proliferation by repairing DNA, arresting the cell cycle, inducing apoptosis, and altering genetic expression. HDAC9 plays a significant part in human physiological system and are involved in various type of diseases like cancer, diabetes, atherosclerosis and CVD, autoimmune response, inflammatory disease, osteoporosis and liver fibrosis. This review discusses the role of HDAC9 in different diseases and structure-activity relationships (SARs) of various hydroxamate and non-hydroxamate-based inhibitors. SAR of compounds containing several scaffolds have been discussed in detail. Moreover, structural requirements regarding the various components of HDAC9 inhibitor (cap group, linker and zinc-binding group) has been highlighted in this review. Though, HDAC9 is a promising target for the treatment of a number of diseases including cancer, a very few research are available. Thus, this review may provide useful information for designing novel HDAC9 inhibitors to fight against different diseases in the future.