Cancer Immunotherapy: Fecal Microbiota Transplantation Brings Light.

OPINION STATEMENT: Immunotherapy is revolutionizing tumor treatment by activating the immune response to tumors. Among them, immunotherapy represented by immune checkpoint inhibitors is considered to be a milestone in tumor treatment. It has revolutionized the management of advanced malignant tumors by activating T cells, promoting cytotoxic signaling pathways, and killing tumor cells, effectively improving the overall survival of patients. However, resistance to immunotherapy and immune-related adverse events remain challenges for immunotherapy. It has been demonstrated in previous studies that modulating intestinal microbiota can enhance immunotherapy response and reduce complications. Currently, the more mature method for microbiota regulation is fecal microbiota transplantation, which involves transfering a donor's microbiome to the recipient in the form of capsules or fecal microbiota suspension to restore the richness of the recipient's intestinal microbiota. In terms of cancer immunotherapy, fecal microbiota transplantation in patients who fail to respond to immune checkpoint inhibitors is expected to produce better prognosis for patients.

Pancreatoblastoma in children: Clinical management and literature review.

PURPOSE: The aim of this study is to analyze the clinical and pathological features of pancreatoblastoma (PB) and to obtain better management for patients with relapsed or metastatic disease. METHODS: Four cases treated in our institution and 59 cases reported previously in the literature from the PubMed biomedical database (2000-2020) were reviewed and analyzed. RESULTS: Four cases with PB presented with abdominal pain and palpable abdominal masses, with the tumor size ranging from 5.2 to 18 cm in diameter. The invasion of the splenic vein and superior mesenteric artery, duodenum, and lymph nodes were risk factors for PB. Three cases were treated with combination therapy and showed favorable outcomes, while one case was treated with chemotherapy alone due to tumor progression and died of the disease. Squamous corpuscles were revealed in the tumor samples and considered a defining component for histological diagnosis. CONCLUSIONS: Multidisciplinary diagnosis plays an important role in clinical management. The risk factors should be considered in the therapeutic stratification of PB before surgery.

Exosomal microRNA-618 derived from mesenchymal stem cells attenuate the progression of hepatic fibrosis by targeting Smad4.

Hepatic fibrosis (HF) is a pathological phenomenon that occurs during the process of long-term damage and repair in the liver. This condition will lead to the development of cirrhosis and even liver cancer if untreated. Previous evidence has shown that exosomes derived from mesenchymal stem cells (MSCs), carrying microRNAs (miRs), can affect the pathogenesis of HF. Therefore, the present study aimed to identify novel exosomal miRs derived from MSCs that play a critical role in the progression of HF. Next, the expression data of differentially expressed miRs (DEMs) of patients with liver cirrhosis and healthy controls were obtained from the Gene Expression Omnibus dataset. DEMs were analyzed using Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Moreover, to further confirm the function of exosomal miR-618 derived from MSCs on the pathogenesis of HF in vivo, a mouse model of HF was established. The results of the present study suggested that a close associated existed between DEMs and HF. Based on the results of the bioinformatics analysis, miR-618 was one of the main downregulated miRs involved in cirrhosis. In addition, miR-618 could be transferred from MSCs to LX-2 cells via exosomes; exosomal miR-618 derived from MSCs inhibited the viability and migration of LX-2 cells that were treated with TGF-ß. Furthermore, exosomal miR-618 derived from MSCs attenuated the progression of HF via targeting Smad4. These findings indicated that treatment of exosomal miR-618 derived from MSCs might serve as a new strategy for HF.

Histone deacetylase inhibitor givinostat attenuates nonalcoholic steatohepatitis and liver fibrosis.

Nonalcoholic steatohepatitis (NASH) is a common chronic liver disease that is increasingly prevalent worldwide. Liver inflammation is an important contributor to disease progression from nonalcoholic fatty liver (NAFL) to NASH, but there is a lack of efficient therapies. In the current study we evaluated the therapeutic potential of givinostat, a histone deacetylase (HDAC) inhibitor, in the treatment of NASH in vivo and in vitro. Liver inflammation was induced in mice by feeding a methionine- and choline-deficient diet (MCD) or a fructose, palmitate, cholesterol diet (FPC). The mice were treated with givoinostat (10 mg·kg-1·d-1, ip) for 8 or 10 weeks. At the end of the experiment, the livers were harvested for analysis. We showed that givoinostat administration significantly alleviated inflammation and attenuated hepatic fibrosis in MCD-induced NASH mice. RNA-seq analysis of liver tissues form MCD-fed mice revealed that givinostat potently blocked expression of inflammation-related genes and regulated a broad set of lipid metabolism-related genes. In human hepatocellular carcinoma cell line HepG2 and human derived fetal hepatocyte cell line L02, givinostat significantly decreased palmitic acid-induced intracellular lipid accumulation. The benefit of givinostat was further confirmed in FPC-induced NASH mice. Givinostat administration significantly attenuated hepatic steatosis, inflammation as well as liver injury in this mouse model. In conclusion, givinostat is efficacious in reversing diet-induced NASH, and may serve as a therapeutic agent for the treatment of human NASH.

Cyclin-dependent kinase inhibitor roscovitine attenuates liver inflammation and fibrosis by influencing initiating steps of liver injury.

Liver diseases present a significant public health burden worldwide. Although the mechanisms of liver diseases are complex, it is generally accepted that inflammation is commonly involved in the pathogenesis. Ongoing inflammatory responses exacerbate liver injury, or even result in fibrosis and cirrhosis. Here we report that roscovitine, a cyclin-dependent kinase (CDK) inhibitor, exerts beneficial effects on acute and chronic liver inflammation as well as fibrosis. Animal models of lipopolysaccharide (LPS)/d-galactosamine- and acute or chronic CCl4-induced liver injury showed that roscovitine administration markedly attenuated liver injury, inflammation and histological damage in LPS/d-galactosamine- and CCl4-induced acute liver injury models, which is consistent with the results in vitro. RNA sequencing (RNA-seq) analysis showed that roscovitine treatment repressed the transcription of a broad set of pro-inflammatory genes involved in many aspects of inflammation, including cytokine production and immune cell proliferation and migration, and inhibited the TGF-ß signaling pathway and the biological process of tissue remodeling. For further validation, the beneficial effect of roscovitine against inflammation was evaluated in chronic CCl4-challenged mice. The anti-inflammation effect of roscovitine was observed in this model, accompanied with reduced liver fibrosis. The anti-fibrotic mechanism involved inhibition of profibrotic genes and blocking of hepatic stellate cell (HSC) activation. Our data show that roscovitine administration protects against liver diseases through inhibition of macrophage inflammatory actions and HSC activation at the onset of liver injury.

Histone deacetylase inhibitor givinostat alleviates liver fibrosis by regulating hepatic stellate cell activation.

Hepatic fibrosis, a common pathological manifestation of chronic liver injury, is generally considered to be the end result of an increase in extracellular matrix produced by activated hepatic stellate cells (HSCs). The aim of the present study was to target the mechanisms underlying HSC activation in order to provide a powerful therapeutic strategy for the prevention and treatment of liver fibrosis. In the present study, a high­throughput screening assay was established, and the histone deacetylase inhibitor givinostat was identified as a potent inhibitor of HSC activation in vitro. Givinostat significantly inhibited HSC activation in vivo, ameliorated carbon tetrachloride­induced mouse liver fibrosis and lowered plasma aminotransferases. Transcriptomic analysis revealed the most significantly regulated genes in the givinostat treatment group in comparison with those in the solvent group, among which, dermokine (Dmkn), mesothelin (Msln) and uroplakin­3b (Upk3b) were identified as potential regulators of HSC activation. Givinostat significantly reduced the mRNA expression of Dmkn, Msln and Upk3b in both a mouse liver fibrosis model and in HSC­LX2 cells. Knockdown of any of the aforementioned genes inhibited the TGF­ß1­induced expression of α­smooth muscle actin and collagen type I, indicating that they are crucial for HSC activation. In summary, using a novel strategy targeting HSC activation, the present study identified a potential epigenetic drug for the treatment of hepatic fibrosis and revealed novel regulators of HSC activation.

Hepatitis B-related glomerulonephritis and optimization of treatment.

Introduction: Multiple studies have revealed a strong relationship between the development of nephropathy and hepatitis B virus (HBV) infection. The underlying pathogenesis of hepatitis B-related glomerulonephritis (HBV-GN) involves immune complexes, which can be isolated from kidney tissues. Clearance of HBV antigenemia improves renal impairment and proteinuria in HBV-GN patients.Areas covered: In this review, we present our current understanding of the epidemiology, pathogenesis, pathology, diagnosis, and treatment of HBV-GN. We discuss the advantages and disadvantages of oral nucleoside/nucleotide analogs (NAs), and the main pharmaceutical treatment for hepatis B.Expert opinion: Currently, antiviral agents are the main HBV-GN therapeutic agents. Although no randomized controlled clinical trials have compared the efficacy of interferon (IFN) and NA, we suggest IFN treatment for pediatric patients (IFN-α in patients ≥1 year; pegIFN-α in patients ≥3 years) considering treatment duration and absence of resistance. Novel NAs have brought about promising treatment options involving high efficacy viral suppression and low resistance rates. NAs with a high barrier to resistance (e.g. entecavir) are recommended as first-line therapy of HBV-GN. Immunosuppression monotherapy, such as corticosteroids, is of little benefit and potentially harmful to HBV-GN patients due to the possibility of viral reactivation.

Protective Effects of Oridonin on Acute Liver Injury via Impeding Posttranslational Modifications of Interleukin-1 Receptor-Associated Kinase 4 (IRAK4) in the Toll-Like Receptor 4 (TLR4) Signaling Pathway.

OBJECTIVE: Recent researches have demonstrated that inflammation-related diseases are effectively regulated by posttranslational modifications (PTMs) including phosphorylation and acetylation. Our previous study found a new acetyltransferase inhibitor, oridonin, which had a protective effect on acute liver injury (ALI). In the present study, we further investigated its protective mechanism against D-galactosamine (D-Gal) combined with lipopolysaccharide- (LPS-) induced ALI in mice. METHODS: Intraperitoneal injections of LPS (40 µg/mouse)/D-Gal (5 mg/mouse) were given to the mice, and the experimental group was pretreated with intraperitoneal injection of oridonin (0.2 mg/mouse). To elucidate the protective mechanism of oridonin, we collected liver specimens and used RNA-sequencing (RNA-Seq) analysis. We focused on the genes that were upregulated by LPS/D-Gal and downregulated after pretreatment with oridonin. The downregulated genes examined by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were further verified by real-time polymerase chain reaction (PCR) and western blot. RESULTS: GO analysis showed that genes that were downregulated after pretreatment with oridonin were extremely concentrated in immune response, chemotaxis, and inflammatory response. Real-time PCR confirmed that the expression of these genes was upregulated by LPS/D-Gal induction and reduced after treatment with oridonin, which was consistent with RNA-Seq results. KEGG pathway analysis showed a significantly enriched downregulated gene that was present in the Toll-like receptor (TLR) 4 signaling cascade. Our results manifested that phosphorylation levels of upstream signaling molecules in the TLR4 signaling cascade, including extracellular signal-regulated kinase (ERK), P38, and IκB, were significantly inhibited by oridonin. Furthermore, LPS/D-Gal stimulation triggered posttranslational modifications of related gene loci in the TLR4 signaling pathway, including phosphorylation of IL-1 receptor-associated kinase 4 (IRAK4 T345/S346) and acetylation of IRAK4 (K34). However, after treatment with oridonin, the modification pattern of IRAK4 expression stimulated by LPS/D-Gal was suggestively attenuated. CONCLUSION: Our study revealed that the protective effects of oridonin on LPS/D-Gal-induced ALI mediated by inhibition of the PTMs of IRAK4, including phosphorylation of T345/S346 and acetylation of K34.

Multiple foci modulation with controllable positions and intensity ratios through decomposed optimization.

In this Letter, multiple foci modulation with controllable positions and intensity ratios is presented with a multi-belt binary phase mask in a tightly focusing system. Different from previous methods, the diffractive optical element (DOE) in our model is first virtually decomposed into two or more simple sub-DOEs. Then, after optimization, the sub-DOEs are combined to form the desired DOE through superposition. By such a decomposed optimization, the optimization complexities are greatly reduced, and the calculation becomes simpler and more effective. Furthermore, since the quantities and structures of sub-DOEs can be adjusted according to the original DOE, the method is very flexible and adaptable. As a demonstration, up to nine foci on the optical axis are studied, and the simulation results show that multiple foci can be well modulated. The proposed method may provide a universal strategy for complex light field modulations in a simple way.

Fabrication of high fill factor cylindrical microlens array with isolated thermal reflow.

We demonstrate a simple, controllable, and stable method for fabricating high fill factor cylindrical microlens array with a novel isolated thermal reflow process. In this method, microstripes with a very small gap were obtained via digital micromirror device-based lithography, then covered with polydimethylsiloxane (PDMS) solution. The prepared microstripes were isolated and were heated and reflowed to a cylindrical microlens array. During the reflow process, the semicross-linked PDMS can serve as a barrier to prevent the diameter change and the bonding of adjacent microlenses. By this special treatment, the fill factor of the cylindrical microlens array can be significantly improved. Moreover, the reflow time and temperature have very little effect on the microlens shape due to the surrounded semicross-linked PDMS. This will make our process stabler than traditional methods. The measured 3D profile is good and satisfactory, and excellent optical performance is demonstrated with the fabricated cylindrical microlens arrays. The proposed method may offer a viable route for fabrication of high fill factor microlens arrays in a very simple and stable way.

Oridonin ameliorates lipopolysaccharide/D-galactosamine-induced acute liver injury in mice via inhibition of apoptosis.

We investigated the protective effects exerted by oridonin, the main active constituent of the Chinese medicinal herb Rabdosiarubescens, against lipopolysaccharide (LPS)/D-galactosamine (D-Gal)-induced acute liver injury (ALI). An ALI model was induced in mice using LPS (40 µg/0.5 ml) and D-Gal (5 mg/0.5 ml). The mice were randomly divided into the following five groups of six mice each: one control group (a), one ALI group (b), two oridonin treatment groups (c and d), and one oridonin control group (e). Oridonin (0.2 mg/0.5 ml) was administered once 1 h prior to the LPS/D-Gal challenge in group c and a total of three times over a period of four days, with the last dose given at 1 h before the LPS/D-Gal challenge, in group d. Pretreatment with oridonin improved the survival rate, alleviated histopathological abnormalities, and suppressed plasma aminotransferases in the LPS/D-Gal-challenged mice. Importantly, oridonin attenuated LPS/D-Gal-induced apoptosis in hepatocytes by reducing pro-apoptotic signals (P<0.05), such as tumor necrosis factor-α (TNF-α) and c-Jun N-terminal kinases (JNK). Furthermore, JNK-associated mitochondrial pro-apoptotic proteins were also suppressed by pretreatment with oridonin. Taken together, these data show that oridonin exerts protective effects against LPS/D-Gal-induced ALI in mice via a mechanism that may involve the suppression of the pro-apoptotic cytokine TNF-α and JNK-associated pro-apoptotic signaling.

Role of CTGF gene promoter methylation in the development of hepatic fibrosis.

Connective tissue growth factor (CTGF) plays a critical role in the hepatic stellate cells (HSCs)-mediated development of hepatic fibrosis. Nevertheless, the effects of CTGF gene promoter methylation in the pathogenesis of hepatic fibrosis remain largely unknown. In the current study, we isolated and overexpressed CTGF in primary HSCs. We analyzed the CTGF gene promoter methylation inHSCs that undergo a phenotypic change into myofibroblast-like cellsthat express α-smooth muscle actin (α-SMA) in vitro and in vivo in a CCl4-induced rat hepatic fibrosis model. We found that CTGF promoted the phenotypic changes of HSCs into myofibroblasts in vitro, while inhibition of CTGF promoter methylation augmented the process, suggesting that CTGF gene promoter methylation may negatively regulate hepatic fibrosis. In vivo, CCl4 induced hepatic fibrosis in rats, and the severity of hepatic fibrosis inversely correlated with the levels of CTGF gene promoter methylation in HSCs. Together, our data demonstrate that CTGF gene promoter methylation may prevent the development of hepatic fibrosis, and low level of CTGF gene promoter methylation in HSCs may be a predisposing factor for developing liver fibrotic disease.

Characterization and flocculability of a novel proteoglycan produced by Talaromyces trachyspermus OU5.

A filamentous fungus strain OU5 was isolated from a soil sample for its ability to produce rich exopolymers (EPS), with high flocculation capability towards kaolin suspension and swine wastewater, at low-carbon source conditions. EPS from strain OU5 was extracted and characterized to determine its flocculating behavior and active constituents involved in the flocculation. Strain OU5 was identified as Talaromyces trachyspermus by 18S rDNA-ITS gene sequencing and morphological observation. The extracted EPS was a novel proteoglycan (designated as BF-OU5) composed of 84.6% (w/w) polysaccharides and 15.2% (w/w) proteins. The enzymatic digestion tests revealed that the polysaccharides in BF-OU5, composed of 67% glucose, 16.4% mannose, 8.6% xylose and 8% galactose, contributed to 99.7% of flocculating capacity and were the major active ingredients in the flocculation. By contrast, the proteins in BF-OU5 only had minor roles in the flocculation. The presence of hydroxyl, amide, carboxyl and methoxyl functional groups in BF-OU5, and the high molecular weight (1.053 × 10(5)-2.970 × 10(5) Da) as well as the structure of a spherical conformation with inner pores and channels made of cross-linked netted textures contributed to the flocculation. A dosage of 20 mg/l BF-OU5 initiated more than 92.5% of flocculating efficiency towards kaolin suspension without any added coagulants; its flocculability was stable over a wide range of pH (4.0-8.0) and temperature (20°C-100°C). Treatment of swine wastewater using BF-OU5 achieved 52.1% flocculating removal for chemical oxygen demand, 39.7% for Kjeldahl nitrogen, 18.6% for NH4(+)-N, 21.5% for total phosphorus, and 75% for turbidity.

Up-regulation of CXCR4 in rat umbilical mesenchymal stem cells induced by serum from rat with acute liver failure promotes stem cells migration to injured liver tissue.

The role of C-X-C chemokine receptor type 4 (CXCR4) in umbilical mesenchymal stem cells (UMSCs) as therapy for liver disease is ill understood. The aim of the study was to evaluate rat UMSCs (rUMSCs) on CXCR4 expression and homing to injured liver tissue. rUMSCs were isolated from umbilical cords of pregnant rats. Acute liver failure (ALF) models were developed using D-galactosamine. CXCR4 expression induction by serum from rats with ALF (LFS), cytokines, growth factors, and LPS was analyzed. CXCR4 expression was analyzed by RT-PCR, western blot, and flow cytometry. rUMSCs were labeled with carboxyfluorescein and pretreated with LFS to induce CXCR4 expression and were transplanted into ALF rats. Animals were sacrificed 48 h and 1 week after transplantation. Liver-homing rUMSCs were observed under fluorescence microscopy. rUMSCs were successfully isolated, expressing CD90 and CD106, but not CD34 and CD45. mRNA and protein expressions of CXCR4 were strongly up-regulated by LFS and by the mixture of cytokines, stem cell factor, and LPS (CM). Expression of cell surface CXCR4 on rUMSCs in groups treated with LFS (42.37 ± 1.60 %) and CM (40.17 ± 1.78 %) was higher than that in the untreated control group (9.67 ± 1.06 %) (both P < 0.001). At 48 h after transplantation, more rUMSCs pretreated with LFS appeared in the portal area, and migrated to the liver parenchyma after 1 week. LFS strongly induced the surface expression of CXCR4 on rUMSCs. Increasing CXCR4 expression on rUMSCs may enhance their homing ability to injured liver tissue, and may eventually be used for treating liver diseases.

Overexpression of the receptor-like protein kinase genes AtRPK1 and OsRPK1 reduces the salt tolerance of Arabidopsis thaliana.

AtRPK1 (AT1G69270) is a leucine-rich repeat receptor-like protein kinase (LRR-RLK) gene in Arabidopsis thaliana. The rice gene Os07g0602700 (OsRPK1) is the homolog of AtRPK1. AtRPK1 and OsRPK1 were overexpressed and the expression of AtRPK1 was inhibited by RNAi in A. thaliana. The functional results showed that the degrees of salt tolerance of the 35S:RPK1 A. thaliana plants were significantly lower than that of the control plants. The AtRPK1-RNAi A. thaliana plants exhibited higher salt tolerance than the wild-type plants (Col). The subcellular localisation results showed that the RPK1 proteins were mainly distributed on the cell membrane and that the overexpressed AtRPK1 proteins exhibited a significantly clustered distribution. The physiological analyses revealed that the overexpression of the RPK1 genes increased the membrane permeability in the transgenic A. thaliana plants. In response to salt stress, these plants exhibited an increased Na(+) flux into the cell, which caused greater damage to the cell. The real-time quantitative PCR analysis showed that the expression of the P5CS1 gene was inhibited and the SOS signalling pathway was blocked in the 35S:AtRPK1 A. thaliana plants. These effects at least partially contribute to the salt-sensitive phenotype of the 35S:RPK1 plants.

Inhibition of lipopolysaccharide-induced iNOS and COX-2 expression by indole alkaloid, 3-(hydroxymethyl)-6,7-dihydroindolo[2,3-a]quinolizin-(12H)-one, via NF-κB inactivation in RAW 264.7 macrophages.

3-(Hydroxymethyl)-6,7-dihydroindolo[2,3-a]quinolizin-(12H)-one is a bioactive indole alkaloid isolated from Nauclea officinalis, a plant species which is used as a traditional Chinese medicine. We investigated the anti-inflammatory properties of 3-(hydroxymethyl)-6,7-dihydroindolo[2,3-a]quinolizin-(12H)-one in RAW 264.7 murine macrophages. The results indicated that it inhibited the overproduction of NO and the release of TNF-α. Furthermore, this compound inhibited the expression of iNOS and COX-2 proteins, the enzymatic activity of iNOS, and the translocation of NF-κB to the nucleus induced by LPS. Therefore, we suggested that the effect of 3-(hydroxymethyl)-6,7-dihydroindolo[2,3-a]quinolizin-(12H)-one-mediated inhibition of the expression of LPS-induced iNOS and COX-2 genes is due to the suppression of NF-κB activation in the transcriptional level.

[Expression and correlation of angiotensin-converting enzyme 2 in CCl4-induced rat liver fibrosis].

OBJECTIVE: To investigate the expression and pathogenic relevance of angiotensin-converting enzyme 2 (ACE2) in liver fibrosis by using the rat model of CCl4-induced liver fibrosis. METHODS: The liver fibrosis model was generated by delivering subcutaneous injections of CCl4 (dissolved in olive oil at a 2:3 ratio; injection dose: 3 ml/kg) every three days for six weeks into male Sprague-Dawley rats. Another group of rats that received simultaneous injections of olive oil alone (3 ml/kg) were used as controls. At week 0, 2, 4, or 6 after the first injection, a subset of rats from each group was sacrificed to obtain liver tissues and serum samples. Pathological analyses were carried out to detect the presence and extent of liver cell degeneration, necrosis, inflammatory cell infiltration, and collagen deposition. ACE2 and ACE gene and protein expressions were measured by real-time PCR and Western blotting, respectively. The significance of differential expression between groups and time points was assessed by t-test and one-way ANOVA or Kruskal-Wallis tests, and correlation with fibrosis was assessed by Spearman's rank correlation coefficient. RESULTS: CCl4 administration led to significantly up-regulated ACE2 mRNA levels at week 2 (3.055+/-1.034), 4 (3.545+/-1.947), and 6 (6.448+/-1.836) (vs. controls; H = 23.224, P less than 0.001). Similarly, hepatic ACE mRNA was significantly increased after the CCl4 injections (week 2: 3.055+/-1.034, week 4: 3.545+/-1.947, week 6: 6.448+/-1.836; vs. controls: F = 12.982, P less than 0.001). There was a significant correlation between the ACE and ACE2 gene expression levels (r = 0.750, P less than 0.001). Protein levels of ACE2 also showed an increasing trend following CCl4 administration (week 0: 0.034, week 2: 0.097, week 4: 0.356, week 6: 0.512). The hepatic ACE2 gene expression strongly correlated with levels of alanine aminotransferase (r = 0.669, P less than 0.0001) and aspartate aminotransferase (r = 0.815, P less than 0.0001), and with the Ishak fibrosis score (r = 0.850, P less than 0.001). Finally, there was a significant correlation between circulating ACE2 and the Ishak fibrosis score (r = 0.730, P less than 0.001). CONCLUSION: A significant relationship exists between ACE2 gene expression and extent of liver fibrosis. ACE2 may play a crucial role in liver fibrogenesis.

Expression of angiotensin-converting enzyme 2 in CCL4-induced rat liver fibrosis.

The renin angiotensin system (RAS) plays a major role in liver fibrosis. A novel homologue of angiotensin converting enzyme, ACE2, was identified as a negative regulator of RAS as it degrades Ang II to Ang1-7. We investigated in vivo the expression of ACE2 in liver fibrosis. We evaluated the relationship between biochemical variables and liver tissue expression of ACE2, the correlation between a histological assessment of liver fibrosis and liver tissue expression of ACE2. Male SD rats were randomly divided into a CCL4 group which received injections of CCL4 and the control group which received injections of olive oil. Liver pathology was examined by H&E and Sirius red staining, and real-time PCR was performed to determine the gene expression levels of ACE2 and ACE. Real-time PCR analysis revealed that ACE2 mRNA was higher at the two-, four-, and six-week time points, respectively (p<0.01). Similarly, hepatic ACE mRNA was significantly increased after CCL4 injection. There was a significant correlation between ACE and ACE2 gene expression (r=0.750, P<0.001). ACE2 gene expression strongly correlated with ALT (r=0.669, P<0.0001) and AST levels (r=0.815, P<0.0001). There was a significant correlation between circulating ACE2 and histological scores of liver fibrosis. ACE2 and ACE gene expression correlated with the ISHAK score (r=0.850, P<0.001; r=0.806, P<0.001). There was a significant relationship between ACE2 gene expression and the degree of liver fibrosis. ACE2 plays a crucial role in liver fibrogenesis.