SUGP2 p.(Arg639Gln) variant is involved in the pathogenesis of hemochromatosis via the CIRBP/BMPER signaling pathway.

Pathogenic variants in HFE and non-HFE genes have been identified in hemochromatosis in different patient populations, but there are still a certain number of patients with unexplained primary iron overload. We recently identified in Chinese patients a recurrent p.(Arg639Gln) variant in SURP and G-patch domain containing 2 (SUGP2), a potential mRNA splicing-related factor. However, the target gene of SUGP2 and affected iron-regulating pathway remains unknown. We aimed to investigate the pathogenicity and underlying mechanism of this variant in hemochromatosis. RNA-seq analysis revealed that SUGP2 knockdown caused abnormal alternative splicing of CIRBP pre-mRNA, resulting in an increased normal splicing form of CIRBP V1, which in turn increased the expression of BMPER by enhancing its mRNA stability and translation. Furthermore, RNA-protein pull-down and RNA immunoprecipitation assays revealed that SUGP2 inhibited splicing of CIRBP pre-mRNA by a splice site variant at CIRBP c.492 and was more susceptible to CIRBP c.492 C/C genotype. Cells transfected with SUGP2 p.(Arg639Gln) vector showed up-regulation of CIRBP V1 and BMPER expression and down-regulation of pSMAD1/5 and HAMP expression. CRISPR-Cas9 mediated SUGP2 p.(Arg622Gln) knock-in mice showed increased iron accumulation in the liver, higher total serum iron, and decreased serum hepcidin level. A total of 10 of 54 patients with hemochromatosis (18.5%) harbored the SUGP2 p.(Arg639Gln) variant and carried CIRBP c.492 C/C genotype, and had increased BMPER expression in the liver. Altogether, the SUGP2 p.(Arg639Gln) variant down-regulates hepcidin expression through the SUGP2/CIRBP/BMPER axis, which may represent a novel pathogenic factor for hemochromatosis.

Umbilical artery thrombosis risk factors and perinatal outcomes.

PURPOSE: The purpose of this study was to investigate the risk factors for umbilical artery thrombosis (UAT) and the relationship between umbilical artery thrombosis and perinatal outcomes. METHODS: This was a retrospective study that enrolled singleton pregnant women who were diagnosed with umbilical artery thrombosis. The control group recruited pregnant woman with three umbilical vessels or those with isolated single umbilical artery (iSUA) who were matched with umbilical artery thrombosis group. The risk factors and perinatal outcomes were compared between the groups. RESULTS: Preconception BMI (OR [95%CI]: 1.212 [1.038-1.416]), abnormal umbilical cord insertion (OR [95%CI]: 16.695 [1.333-209.177]) and thrombophilia (OR [95%CI]: 15.840 [1.112-223.699]) were statistically significant risk factors for umbilical artery thrombosis. An elongated prothrombin time (OR [95%CI]: 2.069[1.091-3.924]) was strongly associated with the occurrence of UAT. The risks of cesarean delivery, preterm birth, fetal growth restriction, neonatal asphyxia, and intraamniotic infection were higher in pregnancies with UAT than in pregnancies with three umbilical vessels or isolated single umbilical artery (P<0.05). Additionally, the incidence of thrombophilia was higher in pregnant women with umbilical artery thrombosis than those with isolated single umbilical artery (P = 0.032). Abnormal umbilical cord insertion was also found to be associated with an elevated risk of iSUA (OR [95%CI]: 15.043[1.750-129.334]). CONCLUSIONS: Abnormal umbilical cord insertion was the risk factor for both umbilical artery thrombosis and isolated single umbilical artery. The pregnancies with umbilical artery thrombosis had a higher risk of the adverse perinatal outcomes.

14-kDa phosphohistidine phosphatase is a potential therapeutic target for liver fibrosis.

Liver fibrosis, a major cause of morbidity and mortality worldwide, leads to liver damage, seriously threatening human health. In our previous study, we demonstrated that 14 kDa phosphohistidine phosphatase (PHP14) was upregulated in fibrotic liver tissue and involved in the migration and lamellipodia formation of hepatic stellate cells (HSCs). In this study, we evaluated PHP14 as a therapeutic target for liver fibrosis and investigated the mechanism by which it mediates liver fibrosis. AAV-shPhpt1 administration significantly attenuates CCl4-induced liver fibrosis in mice. In particular, fibrosis-associated inflammatory infiltration was significantly suppressed after PHP14 knockdown. Mechanistically, PHP14 regulated macrophage recruitment, infiltration, and migration by affecting podosome formation of macrophages. Inhibition of PHP14 decreased the expression of the fibrogenic signature at the early stage of liver fibrogenesis and the activation of HSCs in vivo. Thus, PHP14 can be considered a potential therapeutic target for liver fibrosis.NEW & NOTEWORTHY PHP14 inhibition via adeno-associated virus (AAV)-mediated gene silencing could potently attenuate carbon tetrachloride (CCl4)-induced liver fibrosis. PHP14 could regulate the migration of macrophages to the site of injury in vivo. PHP14 knockdown in vivo influenced the environment of fibrogenesis and relevant signaling pathways, subsequently affecting myofibroblast activation.

Complex ATP7B mutation patterns in Wilson disease and evaluation of a yeast model for functional analysis of variants.

Wilson disease (WD) is a rare autosomal recessive genetic disorder that is associated with various mutations in the ATP7B gene. Although ATP7B variants are frequently identified, the exact mutation patterns remain unknown because of the absence of pedigree studies, and the functional consequences of individual ATP7B variants remain to be clarified. In this study, we recruited 65 clinically diagnosed WD patients from 60 unrelated families. Pedigree analysis showed that besides several ATP7B homozygous variants (8/65, 12.3%), compound heterozygous variants (43/65, 66.2%) were present in the majority of WD patients. There were 20% of the patients had one (12/65, 18.5%) or multiple (1/65, 1.5%) variants in only a single allele, characterized by a high ratio of splicing or frameshift variants. Nine ATP7B variants were cloned into the pAG426GPD yeast expression vector to evaluate their functional consequences, and the results suggested different degrees of functional disruption from mild or uncertain to severe, consistent with the corresponding phenotypes. Our study revealed the complex ATP7B mutation patterns in WD patients and the applicability of a yeast model system to the evaluation of the functional consequences of ATP7B variants, which is essential for WD cases that are difficult to interpret.

Dynamics of elastin in liver fibrosis: Accumulates late during progression and degrades slowly in regression.

Elastin is an amorphous protein highly resistant to elastase degradation and is believed to be the most stable component among the extracellular matrix (ECM) members. Thus the excessive deposition of elastin in advanced liver fibrosis may contribute to the declining reversibility of the disease. Our previous study has found that elastin crosslinking inhibition can effectively arrest liver fibrosis progression. To further understand the roles of elastin involved in liver fibrosis, we systematically investigated the expression, accumulation, and degradation based on dynamic and bidirectional CCl4 -induced liver fibrosis mouse models and visualized the ultrastructure of elastin globules in cultured LX-2 cells. We found that the expression pattern of tropoelastin (soluble elastin) and collagen I was not completely comparable at both the transcriptional and posttranscriptional levels during liver fibrosis progression and regression. Elastin mainly accumulated onto the internodular fibrous septa and enlarged portal areas and intertwined with collagen I at the late stage of liver fibrosis. Three-dimensional analysis of elastin and collagen I by confocal immunofluorescence coupled with biochemical analyses revealed that with respect to collagen, elastin deposition was characterized by late aggregation in progression and slow turnover in regression. In addition, we visualized the dynamic ultrastructure of ECM fibers during liver fibrogenesis and fibrolysis and the ultrastructure of elastin globules self-aggregated by tropoelastin crosslinking. Our current study established new general hallmarks of elastin levels and forms in progressive and regressive liver fibrosis and provided a foundation for further experimental investigation of the growing role of elastin in liver fibrosis regression.

Multitranscriptome analyses reveal prioritized genes specifically associated with liver fibrosis progression independent of etiology.

Elimination or suppression of causative factors can raise the possibility of liver fibrosis regression. However, different injurious stimuli will give fibrosis from somewhat different etiologies, which, in turn, may hamper the discovery of liver fibrosis-specific therapeutic drugs. Therefore, the analogical cellular and molecular events shared by various etiology-evoked liver fibrosis should be clarified. Our present study systematically integrated five publicly available transcriptomic data sets regarding liver fibrosis with different etiologies from the Gene Expression Omnibus database and performed a series of bioinformatics analyses and experimental verifications. A total of 111 significantly upregulated and 16 downregulated genes were identified specific to liver fibrosis independent of any etiology. These genes were predominately enriched in some Kyoto Encyclopedia of Genes and Genomes pathways, including the "PI3K-AKT signaling pathway," "Focal adhesion," and "ECM-receptor interaction." Subsequently, five prioritized liver fibrosis-specific genes, including COL4A2, THBS2, ITGAV, LAMB1, and PDGFRA, were screened. These genes were positively associated with each other and liver fibrosis progression. In addition, they could robustly separate all stages of samples in both training and validation data sets with diverse etiologies when they were regarded as observed variables applied to principal component analysis plots. Expressions of all five genes were confirmed in activated primary mouse hepatic stellate cells (HSCs) and transforming growth factor ß1-treated LX-2 cells. Moreover, THBS2 protein was enhanced in liver fibrosis rodent models, which could promote HSC activation and proliferation and facilitate NOTCH1/JAG1 expression in HSCs. Overall, our current study may provide potential targets for liver fibrosis therapy and aid to a deeper understanding of the molecular underpinnings of liver fibrosis. NEW & NOTEWORTHY Prioritized liver fibrosis-specific genes THBS2, COL4A2, ITGAV, LAMB1, and PDGFRA were identified and significantly associated with liver fibrosis progression and could be combined to discriminate liver fibrosis stages regardless of any etiology. Among the identified prioritized liver fibrosis-specific targets, THBS2 protein was confirmed to be enhanced in liver fibrosis rodent models, which could promote hepatic stellate cell (HSC) activation and proliferation and facilitate NOTCH1/JAG1 expression in HSCs.

A novel SLC40A1 p.Y333H mutation with gain of function of ferroportin: A recurrent cause of haemochromatosis in China.

BACKGROUND & AIMS: Haemochromatosis type 4, also known as ferroportin disease, is an autosomal dominant genetic disorder caused by pathogenic mutations in the SLC40A1 gene, which encodes ferroportin 1 (FPN1). We have identified a novel SLC40A1 p.Y333H mutation in our previous study. In the present study, we tried to investigate the frequency and pathogenicity of the SLC40A1 p.Y333H mutation in haemochromatosis in China. METHODS: Patients were analysed for SLC40A1 p.Y333H as well as mutations in the other classic haemochromatosis-related genes by Sanger sequencing. To analyse iron export capacity of the SLC40A1 p.Y333H mutant, the 293T cells were transfected with the SLC40A1 p.Y333H construct and then treated with hepcidin after exposure to ferric ammonium citrate. Cellular localization of mutant FPN1, expression of FPN1 and intracellular ferritin were analysed by immunofluorescence and Western blotting. RESULTS: Of 22 unrelated cases with primary iron overload, three cases (3/22, 13.6%) harboured the SLC40A1 p.Y333H, with no missense mutations identified in any other classical haemochromatosis-related genes including HFE, HJV, HAMP and TFR2. Pedigree analysis showed that three probands and the son of one proband had haemochromatosis of stage 3, while the son of another proband with age of 16 showed elevated transferrin saturation but normal serum ferritin level. In vitro studies showed the mutant p.Y333H ferroportin was resistant to hepcidin, affecting the subsequent internalization and degradation of FPN1, and was associated with ferroportin gain of function. CONCLUSIONS: The SLC40A1 p.Y333H mutation is associated with gain of function of ferroportin, representing one of the major aetiological factors of haemochromatosis in China.

Non-HFE mutations in haemochromatosis in China: combination of heterozygous mutations involving HJV signal peptide variants.

INTRODUCTION: Hereditary haemochromatosis (HH) caused by a homozygous p.C282Y mutation in haemochromatosis (HFE) gene has been well documented. However, less is known about the causative non-HFE mutation. We aimed to assess mutation patterns of haemochromatosis-related genes in Chinese patients with primary iron overload. METHODS: Patients were preanalysed for mutations in the classic HH-related genes: HFE, HJV, HAMP, TFR2 and SLC40A1. Whole exome sequencing was conducted for cases with variants in HJV signal peptide region. Representative variants were analysed for biological function. RESULTS: None of the cases analysed harboured the HFE p.C282Y; however, 21 of 22 primary iron-overload cases harboured at least one non-synonymous variant in the non-HFE genes. Specifically, p.E3D or p.Q6H variants in the HJV signal peptide region were identified in nine cases (40.9%). In two of three probands with the HJV p.E3D, exome sequencing identified accompanying variants in BMP/SMAD pathway genes, including TMPRSS6 p.T331M and BMP4 p.R269Q, and interestingly, SUGP2 p.R639Q was identified in all the three cases. Pedigree analysis showed a similar pattern of combination of heterozygous mutations in cases with HJV p.E3D or p.Q6H, with SUGP2 p.R639Q or HJV p.C321X being common mutation. In vitro siRNA interference of SUGP2 showed a novel role of downregulating the BMP/SMAD pathway. Site-directed mutagenesis of HJV p.Q6H/p.C321X in cell lines resulted in loss of membrane localisation of mutant HJV, and downregulation of p-SMAD1/5 and HAMP. CONCLUSION: Compound heterozygous mutations of HJV or combined heterozygous mutations of BMP/SMAD pathway genes, marked by HJV variants in the signal peptide region, may represent a novel aetiological factor for HH.

Novel role of apatinib as a multi-target RTK inhibitor in the direct suppression of hepatocellular carcinoma cells.

Although apatinib has been demonstrated with potential antitumor activity in multiple solid tumors, the underlying mechanism of apatinib for the treatment of hepatocellular carcinoma (HCC) remains unclear. In the present study, we explored if there are any direct suppression effects of apatinib on HCC cells and its relevant targets. We investigated the effect of apatinib on viability of five HCC cell lines and an intrahepatic cholangiocarcinoma cell line, and colony formation, apoptosis and migration of representative HCC cells in vitro; and HCC progression in a xenograft mouse model. Using a phospho-receptor tyrosine kinase pathway array with 49 different tyrosine kinases, we screened and verified the tyrosine kinase targets involved in apatinib response. Apatinib treatment significantly inhibited HCC cell viability, proliferation, colony formation, and migration, and enhanced cell apoptosis in a concentration-dependent manner (p < 0.05). Furthermore, apatinib showed a favorable anti-tumor growth effect (71% of inhibition ratio, p < 0.05) in an established human HCC xenograft mice model with good safety. RTK pathway arrays and western blots analysis demonstrated that apatinib significantly downregulated the phosphorylation levels of several tyrosine kinase receptors, particularly PDGFR-α and IGF-IR, and inhibited Akt phosphorylation. These data suggest that the apatinib may have a direct anti-HCC effect as a direct multi-target RTK inhibitor of HCC cells and a promising potentiality in HCC clinical therapies.

Inhibition of lysyl oxidase-like 1 (LOXL1) expression arrests liver fibrosis progression in cirrhosis by reducing elastin crosslinking.

Mature crosslinked-poly-elastin deposition has been found to be associated with liver fibrosis. However, the regulation of crosslinked/insoluble elastin in liver fibrosis remains largely unknown. Here, we investigated the contribution of lysyl oxidases (LOXs) family, mediated elastin crosslinking, to liver fibrogenesis. We established carbon tetrachloride (CCl4)-induced liver fibrotic and cirrhotic models and found that crosslinked/insoluble elastin levels spiked only in cirrhosis stage during disease progression, in comparison to collagen Ι levels which increased continuously though all stages. Among the LOXs family members, only LOX-like 1 (LOXL1) levels were coincident with the appearance of crosslinked/insoluble elastin. These coincidences included that LOXL1 expression increased (34 fold) in cirrhosis, localized with α-smooth muscle actin (SMA) and was absent in normal and fibrotic livers. In LX-2 cells, LOXL1 silencing arrested expression of α-SMA, elastin and collagen Ι. Our previously characterized adeno-associated vector (AAV) 2/8 shRNA was shown to effectively downregulate LOXL1 expression in CCl4 induced fibrosis mice models. These resulted in delicate and thinner septa and less crosslinked elastin, with a 58% loss of elastin area and 51% decrease of collagen area. Our findings strongly suggested that elastin crosslinking and LOXL1 were co-associated with liver cirrhosis, while selective inhibition of LOXL1 arrested disease progression by reducing crosslinking of elastin.

Dosimetric study of GZP6 60 Co high dose rate brachytherapy source.

The purpose of this study was to obtain dosimetric parameters of GZP6 60 Co brachytherapy source number 3. The Geant4 MC code has been used to obtain the dose rate distribution following the American Association of Physicists in Medicine (AAPM) TG-43U1 dosimetric formalism. In the simulation, the source was centered in a 50 cm radius water phantom. The cylindrical ring voxels were 0.1 mm thick for r ≤ 1 cm, 0.5 mm for 1 cm < r ≤ 5 cm, and 1 mm for r > 5 cm. The kerma-dose approximation was performed for r > 0.75 cm to increase the simulation efficiency. Based on the numerical results, the dosimetric datasets were obtained. These results were compared with the available data of the similar 60 Co high dose rate sources and the detailed dosimetric characterization was discussed.

Development and evaluation of an unlabeled probe high-resolution melting assay for detection of ATP7B mutations in Wilson's disease.

BACKGROUND: Wilson's disease (WD) is a rare autosomal recessive disorder characterized by the deposition of copper mainly in the liver or nerve system that leads to their dysfunction. Mutations in the gene encoding ATPase, Cu+ transporting, beta polypeptide (ATP7B) are causative for WD. The aim of this study was to develop a rapid and convenient assay for detection of the three most common causative ATP7B mutations, p.R778L, p.P992L, and p.V1106I. METHODS: Plasmids containing DNA fragments harboring each of the three ATP7B mutations were constructed. High-resolution melting (HRM) analysis was conducted by asymmetric polymerase chain reaction (PCR) amplification with paired primer and unlabeled probe, performed in a 96-well plate formatted LightCycler 480 Real-Time PCR System. The assay was evaluated for accuracy and reproducibility by genotyping of 41 WD cases. RESULTS: The unlabeled probe HRM assays performed on constructs with the p.R778L, p.P992L, and p.V1106I mutations in the ATP7B gene resulted in additional melting peaks. According to the unlabeled probe HRM molecular signature, we could differentiate homozygous mutations from wild-type with the ΔTm (difference between melting temperatures) >4°C, and the coefficient of variation in repeatability tests was <5%. In the validation assay using our method to examine clinical samples, a 100% accuracy rate was achieved. CONCLUSIONS: The newly developed assay to rapidly genotype the ATP7B mutations is convenient, accurate, and reproducible, and represents a favorable alternative to Sanger sequencing in the identification of specific ATP7B mutations.

[A fitted formula for calculating electron beams mean energy in the homogeneous water phantom].

The hybrid pencil beam model (HPBM) is an effective algorithm for calculating electron dose distribution in radiotherapy. The mean energy distribution of incident electron beam in phantom is one of the factors that affect the calculation accuracy of HPBM, especially in field edge areas near the end of the electron range. A new fitted formula based on Monte Carlo (MC) simulation data for electron beams with energy range of 6-20 MeV in the homogeneous water phantom is proposed in this paper. The precision of the fitted formula within the scope of the energy was evaluated by comparing the electron dose distribution of ECWG measured data with that obtained from HPBM which took the mean electron energy that calculated by the fitted formula and the existed empirical formula, respectively. The results showed that the accuracy of dose distribution that obtained by the mean electron energy calculated with the fitted formula increased about 1%.

The role of polydatin in inhibiting oxidative stress through SIRT1 activation: A comprehensive review of molecular targets.

ETHNOPHARMACOLOGICAL RELEVANCE: Reynoutria japonica Houtt is a medicinal plant renowned for its diverse pharmacological properties, including heat-clearing, toxin-removing, blood circulation promotion, blood stasis removal, diuretic action, and pain relief. The plant is commonly utilized in Traditional Chinese Medicine (TCM), and its major bioactive constituents consist of polydatin (PD) and resveratrol (RES). AIM OF THE STUDY: To summarize the relevant targets of PD in various oxidative stress-related diseases through the activation of Silence information regulator1 (SIRT1). Furthermore, elucidating the pharmacological effects and signaling mechanisms to establish the basis for PD's secure clinical implementation and expanded range of application. MATERIALS AND METHODS: Literature published before November 2023 on the structural analysis and pharmacological activities of PD was collected using online databases such as Google Scholar, PubMed, and Web of Science. The keywords were "polydatin", "SIRT1" and "oxidative stress". The inclusion criteria were research articles published in English, including in vivo and in vitro experiments and clinical studies. Non-research articles such as reviews, meta-analyses, and letters were excluded. RESULTS: PD has been found to have significantly protective and curative effects on diseases associated with oxidative stress by regulating SIRT1-related targets including peroxisome proliferator-activated receptor γ coactivator 1-alpha (PGC-1α), nuclear factor erythroid2-related factor 2 (Nrf2), high mobility group box 1 protein (HMGB1), NOD-like receptor thermal protein domain associated protein 3 (NLRP3), p38/p53, as well as endothelial nitric oxide synthase (eNOs), among others. Strong evidence suggests that PD is an effective natural product for treating diseases related to oxidative stress. CONCLUSION: PD holds promise as an effective treatment for a wide range of diseases, with SIRT1-mediated oxidative stress as its potential pathway.

Serum Iron Overload Activates the SMAD Pathway and Hepcidin Expression of Hepatocytes via SMURF1.

Background and Aims: Liver iron overload can induce hepatic expression of bone morphogenic protein (BMP) 6 and activate the BMP/SMAD pathway. However, serum iron overload can also activate SMAD but does not induce BMP6 expression. Therefore, the mechanisms through which serum iron overload activates the BMP/SMAD pathway remain unclear. This study aimed to clarify the role of SMURF1 in serum iron overload and the BMP/SMAD pathway. Methods: A cell model of serum iron overload was established by treating hepatocytes with 2 mg/mL of holo-transferrin (Holo-Tf). A serum iron overload mouse model and a liver iron overload mouse model were established by intraperitoneally injecting 10 mg of Holo-Tf into C57BL/6 mice and administering a high-iron diet for 1 week followed by a low-iron diet for 2 days. Western blotting and real-time PCR were performed to evaluate the activation of the BMP/SMAD pathway and the expression of hepcidin. Results: Holo-Tf augmented the sensitivity and responsiveness of hepatocytes to BMP6. The E3 ubiquitin-protein ligase SMURF1 mediated Holo-Tf-induced SMAD1/5 activation and hepcidin expression; specifically, SMURF1 expression dramatically decreased when the serum iron concentration was increased. Additionally, the expression of SMURF1 substrates, which are important molecules involved in the transduction of BMP/SMAD signaling, was significantly upregulated. Furthermore, in vivo analyses confirmed that SMURF1 specifically regulated the BMP/SMAD pathway during serum iron overload. Conclusions: SMURF1 can specifically regulate the BMP/SMAD pathway by augmenting the responsiveness of hepatocytes to BMPs during serum iron overload.

Crosstalk of lysyl oxidase-like 1 and lysyl oxidase prolongs their half-lives and regulates liver fibrosis through Notch signal.

BACKGROUND: Lysyl oxidase (LOX) family members (LOX and LOXL1 to 4) are crucial copper-dependent enzymes responsible for cross-linking collagen and elastin. Previous studies have revealed that LOX and LOXL1 are the most dramatically dysregulated LOX isoforms during liver fibrosis. However, the crosstalk between them and the underlying mechanisms involved in the profibrotic behaviors of HSCs, as well as the progression of liver fibrosis, remain unclear. METHODS: pCol9GFP-HS4,5Tg mice, Loxl1fl/flGfapCre mice, human HSC line, and primary HSCs were enrolled to study the dysregulation pattern, profibrotic roles, and the potential mechanisms of LOX and LOXL1 interaction involved in the myofibroblast-like transition of HSCs and liver fibrogenesis. RESULTS: LOX and LOXL1 were synergistically upregulated during liver fibrogenesis, irrespective of etiology, together orchestrating the profibrotic behaviors of HSCs. LOX and LOXL1 coregulated in HSCs, whereas LOXL1 dominated in the coregulation loop. Interestingly, the interaction between LOXL1 and LOX prolonged their half-lives, specifically enhancing the Notch signal-mediated myofibroblast-like transition of HSCs. Selective disruption of Loxl1 in Gfap+ HSCs deactivated the Notch signal, inhibited HSC activation, and relieved carbon tetrachloride-induced liver fibrosis. CONCLUSIONS: Our current study confirmed the synergistic roles and the underlying mechanisms of LOXL1 and LOX crosstalk in the profibrotic behaviors of HSCs and liver fibrosis progression, providing experimental evidence for further clear mechanism-based anti-LOXL1 strategy development in the therapy of liver fibrosis.

Targeting thrombospondin-2 retards liver fibrosis by inhibiting TLR4-FAK/TGF-ß signaling.

Background & Aims: Thrombospondin-2 (THBS2) expression is associated with liver fibrosis regardless of etiology. However, the role of THBS2 in the pathogenesis of liver fibrosis has yet to be elucidated. Methods: The in vivo effects of silencing Thbs2 in hepatic stellate cells (HSCs) were examined using an adeno-associated virus vector (serotype 6, AAV6) containing short-hairpin RNAs targeting Thbs2, under the regulatory control of cytomegalovirus, U6 or the α-smooth muscle promoter, in mouse models of carbon tetrachloride or methionine-choline deficient (MCD) diet-induced liver fibrosis. Crosstalk between THBS2 and toll-like receptor 4 (TLR4), as well as the cascaded signaling, was systematically investigated using mouse models, primary HSCs, and human HSC cell lines. Results: THBS2 was predominantly expressed in activated HSCs and dynamically increased with liver fibrosis progression and decreased with regression. Selective interference of Thbs2 in HSCs retarded intrahepatic inflammatory infiltration, steatosis accumulation, and fibrosis progression following carbon tetrachloride challenge or in a dietary model of metabolic dysfunction-associated steatohepatitis. Mechanically, extracellular THBS2, as a dimer, specifically recognized and directly bound to TLR4, activating HSCs by stimulating downstream profibrotic focal adhesion kinase (FAK)/transforming growth factor beta (TGF-ß) pathways. Disruption of the THBS2-TLR4-FAK/TGF-ß signaling axis notably alleviated HSC activation and liver fibrosis aggravation. Conclusions: THBS2 plays a crucial role in HSC activation and liver fibrosis progression through TLR4-FAK/TGF-ß signaling in an autocrine manner, representing an attractive potential therapeutic target for liver fibrosis. Impact and implications: Thrombospondin-2 (THBS2) is emerging as a factor closely associated with liver fibrosis regardless of etiology. However, the mechanisms by which THBS2 is involved in liver fibrosis remain unclear. Here, we showed that THBS2 plays a prominent role in the pathogenesis of liver fibrosis by activating the TLR4-TGF-ß/FAK signaling axis and hepatic stellate cells in an autocrine manner, providing a potential therapeutic target for the treatment of liver fibrosis.

Intracellular labile iron is a key regulator of hepcidin expression and iron metabolism.

BACKGROUND AND AIMS: Liver iron loading can induce hepatic expression of hepcidin and regulate iron metabolism. However, the mechanism by which hepatocyte senses iron loading and further regulates iron metabolism remains unclear. Intracellular labile iron is nonferritin-bound and redox active; it is transitory, and it serves as a crossroads of cellular iron metabolism, the effect of intracellular labile iron in iron metabolism regulation is particularly poorly understood. METHODS: An intracellular labile iron overload cell model was established using ferric ammonium citrate (FAC) and the lipophilic iron chelator 8-hydroxyquinoline (8HQ/FAC). RNA-Seq was performed to screen the genes that were highly expressed exclusively in 8HQ/FAC-treated HepG2 cells. High-iron-diet mice model and Hfe knockout hemochromatosis mice were used to investigate the importance of tumor necrosis factor α (TNFα) in iron metabolism. RESULTS: Intracellular labile iron in hepatocytes had a dual function in iron metabolism: It induced hepatocytes to express hepcidin via endoplasmic reticulum stress-induced transcription factors, and it stimulated expression of bone morphogenic protein 6 (BMP6, regulator of iron metabolism) in liver sinusoidal endothelial cells (LSECs) via promoting the secretion of TNFα by the hepatocytes. Blockade of TNFα dysregulated iron metabolism during iron overload. Furthermore, administration of TNFα could reduce iron burden in Hfe knockout hemochromatosis mice. CONCLUSIONS: Our findings reveal the importance of intracellular labile iron in iron metabolism, and propose that TNFα might be a novel therapeutic target for HFE-associated hemochromatosis.

Risk factors for postpartum hemorrhage in twin pregnancies with cesarean section.

The rates of twin pregnancies and cesarean section have increased in recent years, and both of them are at high risks of postpartum hemorrhage (PPH). However, few studies have concentrated on the risks of PPH in twin pregnancies and cesarean deliveries. In this study, we aimed to identify the risk factors for PPH among twin-pregnant women with cesarean section. This was a retrospective observational study including 1,649 women with twin pregnancies delivered by cesarean section from 2016 to 2022 in the Second Affiliated Hospital of Wenzhou Medical University, China. The eligible women were divided into PPH group (n = 116) and non-PPH group (n = 1,533) according to the blood loss after delivery within 24 h. The baseline maternal and perinatal characteristics were compared between the two groups. Logistic regression analysis was conducted to identify the potential risk factors for PPH. We found nulliparity, assisted reproductive technology (ART) usage, preeclampsia or HELLP syndrome, placenta previa, placenta accreta and general anesthesia were more common in PPH group than non-PPH group (P < 0.05). Women in PPH group had higher maternal body mass index at delivery and higher combined birthweight of the twins than non-PPH group, but had lower parity (P < 0.05). Seven independent risk factors for PPH were identified after logistic regression analysis: ART usage (OR 2.354 95% CI 1.357-4.083, P = 0.002), preeclampsia or HELLP syndrome (OR 2.605, 95% CI 1.471-4.616, P = 0.001), placenta previa (OR 7.325, 95% CI 3.651-14.697, P < 0.001), placenta accreta (OR 6.296, 95% CI 1.316-30.12, P = 0.021), thrombocytopenia (OR 1.636, 95% CI 1.056-2.535, P = 0.027), general anesthesia (OR 2.394, 95% CI 1.223-4.686, P = 0.011), and combined birthweight (OR 1.00032, 95% CI 1.00005-1.00059, P = 0.020). Collectively, in women with twin pregnancies delivered by cesarean section, the use of ART, preeclampsia or HELLP syndrome, placenta previa, placenta accreta, thrombocytopenia, general anesthesia and the combined birthweight were identified as independent risk factors for PPH. More attention should be paid to women with these risk factors.