Ultrasound treatment alleviates external pericarp browning and improves fruit quality of pomegranate during storage.

BACKGROUND: Ultrasound treatment has a beneficial role in horticultural production from harvest to consumption. The quality traits and microbiological load in pomegranate fruit were explored during 30 days' storage at 20 °C after 10 min and 30 min ultrasound treatments. RESULTS: Ultrasound treatment significantly reduced the microbiological load during storage, providing a relatively clean and suitable storage environment. This was especially true for the 30 min treatment, which also maintained relatively lower weight loss and kept the browning rate below 5% during storage. Meanwhile, the fruit treated with ultrasound had higher ascorbic acid and anthocyanin content, which provided better antibacterial properties and higher nutraceutical properties until the end of storage. The 30 min ultrasound treatment significantly delayed the decrease in catalase (CAT) enzyme activity and the increase in peroxidase (POD) enzyme activity. Combined with weighted gene co-expression network analysis (WGCNA), and correlation analysis, color indicators and antioxidant activity induced by ultrasound treatment were responsible for the relatively higher fruit quality of pomegranate. CONCLUSION: Ultrasound treatment can improve the sensory quality and nutritional characteristics of pomegranate fruits during storage, and reduce the microbiological load. Ultrasound for 30 min was better than 10 min for prolonging the storage life of pomegranate. Our results will provide valuable information for ultrasound application in other horticultural products. © 2023 Society of Chemical Industry.

Core-Shell-Shell Upconversion Nanomaterials Applying for Simultaneous Immunofluorescent Detection of Fenpropathrin and Procymidone.

This study synthesized the NaGdF4@NaGdF4: Yb, Tm@NaGdF4: Yb, Nd upconversion nanoparticles (UCNPs), combined with another three-layer structure NaYF4@NaYF4: Yb, Er@NaYF4 UCNPs, with a core-shell-shell structure, effectively suppressing fluorescence quenching and significantly improving upconversion luminescence efficiency. Two types of modified UCNPs were coupled with antibodies against fenpropathrin and procymidone to form signal probes, and magnetic nanoparticles were coupled with antigens of fenpropathrin and procymidone to form capture probes. A rapid and sensitive fluorescence immunoassay for the simultaneous detection of fenpropathrin and procymidone was established based on the principle of specific binding of antigen and antibody and magnetic separation technology. Under the optimal competitive reaction conditions, different concentrations of fenpropathrin and procymidone standards were added to collect the capture probe-signal probe complex. The fluorescence values at 542 nm and 802 nm were measured using 980 nm excitation luminescence. The results showed that the detection limits of fenpropathrin and procymidone were 0.114 µg/kg and 0.082 µg/kg, respectively, with sensitivities of 8.15 µg/kg and 7.98 µg/kg, and they were applied to the detection of fenpropathrin and procymidone in tomatoes, cucumbers, and cabbage. The average recovery rates were 86.5~100.2% and 85.61~102.43%, respectively, with coefficients of variation less than 10%. The results showed good consistency with the detection results of high-performance liquid chromatography, proving that this method has good accuracy and is suitable for the rapid detection of fenpropathrin and procymidone in food.

Evaluation of drug sensitivity, immunological characteristics, and prognosis in melanoma patients using an endoplasmic reticulum stress-associated signature based on bioinformatics and pan-cancer analysis.

We aimed to develop endoplasmic reticulum (ER) stress-related risk signature to predict the prognosis of melanoma and elucidate the immune characteristics and benefit of immunotherapy in ER-related risk score-defined subgroups of melanoma based on a machine learning algorithm. Based on The Cancer Genome Atlas (TCGA) melanoma dataset (n = 471) and GTEx database (n = 813), 365 differentially expressed ER-associated genes were selected using the univariate Cox model and LASSO penalty Cox model. Ten genes impacting OS were identified to construct an ER-related signature by using the multivariate Cox regression method and validated with the Gene Expression Omnibus (GEO) dataset. Thereafter, the immune features, CNV, methylation, drug sensitivity, and the clinical benefit of anticancer immune checkpoint inhibitor (ICI) therapy in risk score subgroups, were analyzed. We further validated the gene signature using pan-cancer analysis by comparing it to other tumor types. The ER-related risk score was constructed based on the ARNTL, AGO1, TXN, SORL1, CHD7, EGFR, KIT, HLA-DRB1 KCNA2, and EDNRB genes. The high ER stress-related risk score group patients had a poorer overall survival (OS) than the low-risk score group patients, consistent with the results in the GEO cohort. The combined results suggested that a high ER stress-related risk score was associated with cell adhesion, gamma phagocytosis, cation transport, cell surface cell adhesion, KRAS signalling, CD4 T cells, M1 macrophages, naive B cells, natural killer (NK) cells, and eosinophils and less benefitted from ICI therapy. Based on the expression patterns of ER stress-related genes, we created an appropriate predictive model, which can also help distinguish the immune characteristics, CNV, methylation, and the clinical benefit of ICI therapy. KEY MESSAGES: Melanoma is the cutaneous tumor with a high degree of malignancy, the highest fatality rate, and extremely poor prognosis. Model usefulness should be considered when using models that contained more features. We constructed the Endoplasmic Reticulum stress-associated signature using TCGA and GEO database based on machine learning algorithm. ER stress-associated signature has excellent ability for predicting prognosis for melanoma.

A novel Cuprotosis-related signature predicts the prognosis and selects personal treatments for melanoma based on bioinformatics analysis.

Background: Melanoma is a common and aggressive cutaneous malignancy characterized by poor prognosis and a high fatality rate. Recently, due to the application of Immune-checkpoint inhibitors (ICI) in melanoma treatment, melanoma patients' prognosis has been tremendously improved. However, the treatment effect varies quite differently from patient to patient. In this study, we aim to construct and validate a Cuproptosis-related risk model to improve outcome prediction of ICIs in melanoma and divide patients into subtypes with different Cuproptosis-related genes. Methods: Here, according to differentially expressed genes from four melanoma datasets in GEO (Gene Expression Omnibus), and one in TCGA (The Cancer Genome Atlas) database, a novel signature was developed through LASSO and Cox regression analysis. We used 781 melanoma samples to examine the molecular subtypes associated with Cuproptosis-related genes and studied the related gene mutation and TME cell infiltration. Patients with melanoma can be divided into at least three subtypes based on gene expression profile. Survival pan-cancer analysis was also conducted for melanoma patients. Results: The Cuproptosis risk score can predict tumor immunity, subtype, survival, and drug sensitivity for melanoma. And Cuproptosis-associated subtypes can help predict therapeutic outcomes. Conclusion: Cuproptosis risk score is a promising potential biomarker in cancer diagnosis, molecular subtypes determination, TME cell infiltration characteristics, and therapy response prediction in melanoma patients.

In situ preparation of a Co4S3-based electrocatalyst by taking advantage of the controllable components of metal-organic frameworks.

In order to give full play to the advantages in structure tailoring and quantitative assembly, metal-organic frameworks (MOFs) with different topological structures formed by the self-assembly of inorganic ligands containing sulfur, cobalt ions and large-size ligands were used to prepare electrocatalyst materials for hydrolysis with controllable composition and performance. According to the synthesis proposition, we can not only avoid using additional doped sulfur sources to reduce waste but also make it very convenient for Co and sulfur elements to be uniformly and controllably distributed in the whole material, and enhance the overall synergistic effects. Based on the above considerations, two-dimensional layered and three-dimensional MOFs, Co-MOF-1, and Co-MOF-2, with the same chemical compositions were utilized as the templates, and a series of Co/S-based materials with variable compositions and properties were obtained only by controlling the pyrolysis temperature. For each MOF series, it can be observed that with the increase in the pyrolysis temperature, the derivatives gradually change from Co4S3 to Co9S8 composites, which could be proven by PXRD studies. The electrocatalytic properties of two series of derivatives were also investigated, and the results indicate that the materials containing Co4S3 can indeed show better water-splitting performance than Co9S8 ones. Furthermore, the macroscopic stacking form of the MOF template also plays an important role in determining the electrocatalytic performance of the derived materials. Through an overall comparison, it is found that the electrocatalytic performance of the Co-MOF-1 series is better than that of the Co-MOF-2 series at various temperatures, which should be only caused by the natural packing modes of the pristine MOF template. For Co-MOF-1 derivatives, the retention of the two-dimensional layered structure is favorable to form an electrostatic charge separation layer and electron transport channel, which is beneficial to the intercalation and delamination of hydroxide ions, thus improving the storage capacity of materials, promoting electron transfer, and producing less electron transfer resistance. Therefore, based on the research results, the reasonable design of layered MOF materials containing the specific sulfur-containing linker as water-splitting catalysts is an applicable route for the preparation of economical, environmentally friendly, and low energy consumption electrocatalysts, which should receive increasing attention in the future.

Highly Effective OER Electrocatalysts Generated from a Two-Dimensional Metal-Organic Framework Including a Sulfur-Containing Linker without Doping.

Metal-organic frameworks (MOFs) with different topologies formed by the self-assembly of sulfur-containing inorganic ligands, cobalt ions, and large ligands can be used to prepare electrocatalysts for water splitting in order to fully explore the advantages of MOFs in terms of structural tailoring and quantitative assembly. It is possible to avoid using an extradoped sulfur source to reduce waste as well as to disperse Co and sulfur elements evenly and controllably throughout the final material to maximize the overall synergistic effect. In this work, different kinds of bimetallic MOF materials containing sulfur can be synthesized very conveniently by using an economical and practical diffusion method. These materials are directly used as OER electrocatalysts, and the bimetallic MOFs have the best electrocatalytic performance when the ratio of Co to Fe is 6:4. The overpotential at a current density of 10 mA cm-2 was 260 mV, with a Tafel slope of 56 mV dec-1 and good stability. It was assembled with 20% commercial Pt/C material into a two-electrode system for all-water decomposition, and the decomposition voltage at 10 mA cm-2 was 1.81 V. From the electronic configuration microscopic point of view, the introduction of iron ions changed the original synergistic effect for Co-S-Co, which more easily led to the formation of high-valence Co3+ and finally produced highly active electrocatalytic sites. From a macroscopic point of view, the material produced in situ during the electrochemical reaction process not only retains the original 2D layered structure but also utilizes bubbles to produce a loose structure with defective sites. These structural features are advantageous because they provide not only an abundance of active sites and permeable channels but also the necessary interfaces and electron-transport channels for the formation of electrostatic charge-separation layers, making it easier to intercalate and delaminate the hydroxide ions. Furthermore, the changed hydroxyl ions and nitrogen and sulfur atoms on the channel surface may operate as interaction sites, increasing the surface characteristics, facilitating electron transfer, and reducing electron-transfer resistance. To summarize, the rational design of sulfur-containing layered MOF materials directly as water-splitting catalysts is a crucial next step in developing cost-effective, environmentally friendly, and low-energy-consumption electrocatalysts based on the findings of this study.

Synthesis, Structures, and Sorption Properties of Two New Metal-Organic Frameworks Constructed by the Polycarboxylate Ligand Derived from Cyclotriphosphazene.

Solvothermal reactions of hexakis(4-carboxyphenoxy)cyclotriphospazene (H6L1) with copper ions in DMF/H2O produced one complex, {[Cu6(L1)2(OH)(H2O)3]·guest} n (1), but with copper ions and auxiliary rigid 4,4-bipyridine (bpy) produced another new complex, namely, {[Cu3(L1)(bpy)(H2O)6]·guest} n (2). These complexes had been characterized by IR spectroscopy, elemental analysis, and X-ray structural determination. 1 exhibits a 3D anionic structure with the binodal 4,8-connected network with Schläfli symbol {46}2{49·618·8}, consisting of Cu6 clusters and L1 ligands. In contrast, complex 2 possesses a different 3D network with trinodal 3,4,6-c topology with Schläfli symbol {4·62}2{42·66·85·102}{64·8·10}. In these two complexes, the semirigid hexacarboxylate ligands adopt distinct conformations to connect metal ions/clusters, which must be ascribed to the addition of the auxiliary rigid ligand in reaction systems. In addition, gas absorption properties of 1 and 2 including CO2 and N2 were further investigated.

Generation of glucocorticoid-resistant SARS-CoV-2 T cells for adoptive cell therapy.

Adoptive cell therapy with virus-specific T cells has been used successfully to treat life-threatening viral infections, supporting application of this approach to coronavirus disease 2019 (COVID-19). We expand severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) T cells from the peripheral blood of COVID-19-recovered donors and non-exposed controls using different culture conditions. We observe that the choice of cytokines modulates the expansion, phenotype, and hierarchy of antigenic recognition by SARS-CoV-2 T cells. Culture with interleukin (IL)-2/4/7, but not under other cytokine-driven conditions, results in more than 1,000-fold expansion in SARS-CoV-2 T cells with a retained phenotype, function, and hierarchy of antigenic recognition compared with baseline (pre-expansion) samples. Expanded cytotoxic T lymphocytes (CTLs) are directed against structural SARS-CoV-2 proteins, including the receptor-binding domain of Spike. SARS-CoV-2 T cells cannot be expanded efficiently from the peripheral blood of non-exposed controls. Because corticosteroids are used for management of severe COVID-19, we propose an efficient strategy to inactivate the glucocorticoid receptor gene (NR3C1) in SARS-CoV-2 CTLs using CRISPR-Cas9 gene editing.

Generation of glucocorticoid resistant SARS-CoV-2 T-cells for adoptive cell therapy.

Adoptive cell therapy with viral-specific T cells has been successfully used to treat life-threatening viral infections, supporting the application of this approach against COVID-19. We expanded SARS-CoV-2 T-cells from the peripheral blood of COVID-19-recovered donors and non-exposed controls using different culture conditions. We observed that the choice of cytokines modulates the expansion, phenotype and hierarchy of antigenic recognition by SARS-CoV-2 T-cells. Culture with IL-2/4/7 but not other cytokine-driven conditions resulted in >1000 fold expansion in SARS-CoV-2 T-cells with a retained phenotype, function and hierarchy of antigenic recognition when compared to baseline (pre-expansion) samples. Expanded CTLs were directed against structural SARS-CoV-2 proteins, including the receptor-binding domain of Spike. SARS-CoV-2 T-cells could not be efficiently expanded from the peripheral blood of non-exposed controls. Since corticosteroids are used for the management of severe COVID-19, we developed an efficient strategy to inactivate the glucocorticoid receptor gene ( NR3C1 ) in SARS-CoV-2 CTLs using CRISPR-Cas9 gene editing.

Relationships of accelerometer-based measured objective physical activity and sedentary behaviour with cognitive function: a comparative cross-sectional study of China's elderly population.

BACKGROUND: This study explored the effects of physical activity and sedentary behaviour on the decline of cognitive ability among the elderly. To compensate for the limitations of self-reported physical activity, objective measures were used. METHODS: A cross-sectional survey of 308 aged people mean 68.66 ± 5.377 years, in Nanjing, China, was conducted. Physical activity was measured using the ActiGraph GT3X+, and cognitive function was measured using the Montreal Cognitive Assessment. RESULTS: The overall participant model, adjusted for age, BMI, education, and monthly average income, found that light physical activity (ß = 0.006, p < 0.01), moderate-vigorous physical activity (ß = 0.068, p < 0.001), and total physical activity (ß = 0.006, p < 0.01) had a significant linear relationship with cognitive ability, while sedentary time did not (ß = - 0.020, p>0.05). Further, light physical activity only affects the cognitive ability of elderly females (ß = 0.006, p < 0.05). There was an inverted 'U' association between moderate-vigorous physical activity and cognitive ability. The association models found that moderate-vigorous physical activity in the 22.13 min·day- 1~38.79 min·day- 1 range affected cognitive ability most beneficially, with the highest beta coefficient among all groups (ß = 0.091, p < 0.05). CONCLUSIONS: While physical activity can significantly improve cognitive ability among the elderly, sedentary behaviour is associated with decreased cognitive function across genders.

'Turn-on' fluorescence sensing of hydrogen peroxide in marine food samples using a carbon dots-MnO2 probe.

A 'turn-on' fluorescence method for detection of hydrogen peroxide (H2 O2 ) in marine food samples is presented in this article. Using this method, a carbon dots (CDs)-MnO2 probe was formed in which fluorescence intensity (FI) of CDs was quenched through fluorescence resonance energy transfer by addition of MnO2 nanosheets. When H2 O2 was added into the CDs-MnO2 solution, the MnO2 nanosheets formed Mn2+ ions due to a redox reaction between H2 O2 and MnO2 nanosheets, and CD FI was recovered. Under optimized conditions, the detection limit for H2 O2 was 0.87 µM, and analytical linear range was 4-100 µM. Furthermore, this developed fluorescence sensing system was successfully used with satisfactory results to determine trace H2 O2 content in marine food samples.

A novel immature natural killer cell subpopulation predicts relapse after cord blood transplantation.

Natural killer (NK) cells are highly heterogeneous, with vast phenotypic and functional diversity at the single-cell level. They are involved in the innate immune response against malignant and virus-infected cells. To understand the effect of NK diversity during immune recovery on the antitumor response after cord blood transplantation (CBT), we used high-dimensional mass cytometry and the metrics of NK cell diversity to study the NK cell repertoire in serial samples from 43 CBT recipients. A higher-diversity index based on single-cell combinatorial phenotypes was significantly associated with a lower risk for relapse after CBT (P = .005). Cytomegalovirus reactivation was a major factor in the development of a more diverse NK repertoire after CBT. Notably, we identified a group of patients whose CB-derived NK cells after transplantation possessed an immature phenotype (CB-NKim), characterized by poor effector function and a low diversity index. Frequencies of CB-NKim of 11.8% or higher during the early post-CBT recovery phase were highly predictive for relapse (area under the curve [AUC], 0.979), a finding that was validated in a second independent cohort of patients (n = 25; AUC, 0.977). Moreover, we showed that the maturation, diversity, and acquisition of effector function by CB-NKim early after CBT were driven by interleukin 15. Our data indicate that the diversity of the NK cell repertoire after CBT contributes importantly to the risk for subsequent relapse. We suggest that the use of diversity metrics and high-dimensional mass cytometry may be useful tools in predicting clinical outcomes and informing the design of therapeutic strategies to prevent relapse after CBT.

Role of splenic reservoir monocytes in pulmonary vascular monocyte accumulation in experimental hepatopulmonary syndrome.

BACKGROUND AND AIM: Pulmonary monocyte infiltration plays a significant role in the development of angiogenesis in experimental hepatopulmonary syndrome (HPS) after common bile duct ligation (CBDL). Hepatic monocytes are also increased after CBDL, but the origins remain unclear. Splenic reservoir monocytes have been identified as a major source of monocytes that accumulate in injured tissues. Whether splenic monocytes contribute to monocyte alterations after CBDL is unknown. This study evaluates monocyte distributions and assesses effects of splenectomy on monocyte levels and pulmonary vascular and hepatic abnormalities in experimental HPS. METHODS: Splenectomy was performed in CBDL animals. Monocyte levels in different tissues and circulation were assessed with CD68. Pulmonary alterations of HPS were evaluated with vascular endothelial growth factor-A (VEGF-A) levels, angiogenesis, and alveolar-arterial oxygen gradient (AaPO2 ). Liver abnormalities were evaluated with fibrosis (Sirius red), bile duct proliferation (CK-19), and enzymatic changes. RESULTS: Monocyte levels increased in the lung and liver after CBDL and were accompanied by elevated circulating monocyte numbers. Splenectomy significantly decreased monocyte accumulation, VEGF-A levels, and angiogenesis in CBDL animal lung and improved AaPO2 levels. In contrast, hepatic monocyte levels, fibrosis, and functional abnormalities were further exacerbated by spleen removal. CONCLUSIONS: Splenic reservoir monocytes are a major source for lung monocyte accumulation after CBDL, and spleen removal attenuates the development of experimental HPS. Liver monocytes may have different origins, and accumulation is exacerbated after depletion of splenic reservoir monocytes. Tissue specific monocyte alterations, influenced by the spleen reservoir, have a significant impact on pulmonary complications of liver disease.

Alveolar type II epithelial cell dysfunction in rat experimental hepatopulmonary syndrome (HPS).

The hepatopulmonary syndrome (HPS) develops when pulmonary vasodilatation leads to abnormal gas exchange. However, in human HPS, restrictive ventilatory defects are also observed supporting that the alveolar epithelial compartment may also be affected. Alveolar type II epithelial cells (AT2) play a critical role in maintaining the alveolar compartment by producing four surfactant proteins (SPs, SP-A, SP-B, SP-C and SP-D) which also facilitate alveolar repair following injury. However, no studies have evaluated the alveolar epithelial compartment in experimental HPS. In this study, we evaluated the alveolar epithelial compartment and particularly AT2 cells in experimental HPS induced by common bile duct ligation (CBDL). We found a significant reduction in pulmonary SP production associated with increased apoptosis in AT2 cells after CBDL relative to controls. Lung morphology showed decreased mean alveolar chord length and lung volumes in CBDL animals that were not seen in control models supporting a selective reduction of alveolar airspace. Furthermore, we found that administration of TNF-α, the bile acid, chenodeoxycholic acid, and FXR nuclear receptor activation (GW4064) induced apoptosis and impaired SP-B and SP-C production in alveolar epithelial cells in vitro. These results imply that AT2 cell dysfunction occurs in experimental HPS and is associated with alterations in the alveolar epithelial compartment. Our findings support a novel contributing mechanism in experimental HPS that may be relevant to humans and a potential therapeutic target.

Endothelin-1 activation of the endothelin B receptor modulates pulmonary endothelial CX3CL1 and contributes to pulmonary angiogenesis in experimental hepatopulmonary syndrome.

Hepatic production and release of endothelin-1 (ET-1) binding to endothelin B (ETB) receptors, overexpressed in the lung microvasculature, is associated with accumulation of pro-angiogenic monocytes and vascular remodeling in experimental hepatopulmonary syndrome (HPS) after common bile duct ligation (CBDL). We have recently found that lung vascular monocyte adhesion and angiogenesis in HPS involve interaction of endothelial C-X3-C motif ligand 1 (CX3CL1) with monocyte CX3C chemokine receptor 1 (CX3CR1), although whether ET-1/ETB receptor activation influences these events is unknown. Our aim was to define if ET-1/ETB receptor activation modulates CX3CL1/CX3CR1 signaling and lung angiogenesis in experimental HPS. A selective ETB receptor antagonist, BQ788, was given for 2 weeks to 1-week CBDL rats. ET-1 (±BQ788) was given to cultured rat pulmonary microvascular endothelial cells overexpressing ETB receptors. BQ788 treatment significantly decreased lung angiogenesis, monocyte accumulation, and CX3CL1 levels after CBDL. ET-1 treatment significantly induced CX3CL1 production in lung microvascular endothelial cells, which was blocked by inhibitors of Ca(2+) and mitogen-activated protein kinase (MEK)/ERK pathways. ET-1-induced ERK activation was Ca(2+) independent. ET-1 administration also increased endothelial tube formation in vitro, which was inhibited by BQ788 or by blocking Ca(2+) and MEK/ERK activation. CX3CR1 neutralizing antibody partially inhibited ET-1 effects on tube formation. These findings identify a novel mechanistic interaction between the ET-1/ETB receptor axis and CX3CL1/CX3CR1 in mediating pulmonary angiogenesis and vascular monocyte accumulation in experimental HPS.

The role of receptor tyrosine kinase activation in cholangiocytes and pulmonary vascular endothelium in experimental hepatopulmonary syndrome.

Pulmonary vascular dilation and angiogenesis underlie experimental hepatopulmonary syndrome (HPS) induced by common bile duct ligation (CBDL) and may respond to receptor tyrosine kinase (RTK) inhibition. Vascular endothelial growth factor-A (VEGF-A) expression occurs in proliferating cholangiocytes and pulmonary intravascular monocytes after CBDL, the latter contributing to angiogenesis. CBDL cholangiocytes also produce endothelin-1 (ET-1), which triggers lung vascular endothelin B receptor-mediated endothelial nitric oxide synthase (eNOS) activation and pulmonary intravascular monocyte accumulation. However, whether RTK pathway activation directly regulates cholangiocyte and pulmonary microvascular alterations in experimental HPS is not defined. We assessed RTK pathway activation in cholangiocytes and lung after CBDL and the effects of the type II RTK inhibitor sorafenib in experimental HPS. Cholangiocyte VEGF-A expression and ERK activation accompanied proliferation and increased hepatic and circulating ET-1 levels after CBDL. Sorafenib decreased each of these events and led to a reduction in lung eNOS activation and intravascular monocyte accumulation. Lung monocyte VEGF-A expression and microvascular Akt and ERK activation were also found in vivo after CBDL, and VEGF-A activated Akt and ERK and angiogenesis in rat pulmonary microvascular endothelial cells in vitro. Sorafenib inhibited VEGF-A-mediated signaling and angiogenesis in vivo and in vitro and improved arterial gas exchange and intrapulmonary shunting. RTK activation in experimental HPS upregulates cholangiocyte proliferation and ET-1 production, leading to pulmonary microvascular eNOS activation, intravascular monocyte accumulation, and VEGF-A-mediated angiogenic signaling pathways. These findings identify a novel mechanism in cholangiocytes through which RTK inhibition ameliorates experimental HPS.

The role of CX3CL1/CX3CR1 in pulmonary angiogenesis and intravascular monocyte accumulation in rat experimental hepatopulmonary syndrome.

BACKGROUND & AIMS: Hepatopulmonary syndrome (HPS), classically attributed to intrapulmonary vascular dilatation, occurs in 15-30% of cirrhotics and causes hypoxemia and increases mortality. In experimental HPS after common bile duct ligation (CBDL), monocytes adhere in the lung vasculature and produce vascular endothelial growth factor (VEGF)-A and angiogenesis ensues and contribute to abnormal gas exchange. However, the mechanisms for these events are unknown. The chemokine fractalkine (CX(3)CL1) can directly mediate monocyte adhesion and activate VEGF-A and angiogenesis via its receptor CX(3)CR1 on monocytes and endothelium during inflammatory angiogenesis. We explored whether pulmonary CX(3)CL1/CX(3)CR1 alterations occur after CBDL and influence pulmonary angiogenesis and HPS. METHODS: Pulmonary CX(3)CL1/CX(3)CR1 expression and localization, CX(3)CL1 signaling pathway activation, monocyte accumulation, and development of angiogenesis and HPS were assessed in 2- and 4-week CBDL animals. The effects of a neutralizing antibody to CX(3)CR1 (anti-CX(3)CR1 Ab) on HPS after CBDL were evaluated. RESULTS: Circulating CX(3)CL1 levels and lung expression of CX(3)CL1 and CX(3)CR1 in intravascular monocytes and microvascular endothelium increased in 2- and 4-week CBDL animals as HPS developed. These events were accompanied by pulmonary angiogenesis, monocyte accumulation, activation of CX(3)CL1 mediated signaling pathways (Akt, ERK) and increased VEGF-A expression and signaling. Anti-CX(3)CR1 Ab treatment reduced monocyte accumulation, decreased lung angiogenesis and improved HPS. These events were accompanied by inhibition of CX(3)CL1 signaling pathways and a reduction in VEGF-A expression and signaling. CONCLUSIONS: Circulating CX(3)CL1 levels and pulmonary CX(3)CL1/CX(3)CR1 expression and signaling increase after CBDL and contribute to pulmonary intravascular monocyte accumulation, angiogenesis and development of experimental HPS.