Visfatin Exerts Immunotherapeutic Effects in Lipopolysaccharide-Induced Acute Lung Injury in Murine Model

Chronic arsenic exposure-provoked biotoxicity involved in liver-microbiota-gut axis disruption in chickens based on multi-omics technologies

INTRODUCTION

Arsenic has been ranked as the most hazardous substance by the U.S. Agency for Toxic Substances and Disease Registry. Environmental arsenic exposure-evoked health risks have become a vital public health concern worldwide owing to the widespread existence of arsenic. Multi-omics is a revolutionary technique to data analysis providing an integrated view of bioinformation for comprehensively and systematically understanding the elaborate mechanism of diseases.

OBJECTIVES

This study aimed at uncovering the potential contribution of liver-microbiota-gut axis in chronic inorganic arsenic exposure-triggered biotoxicity in chickens based on multi-omics technologies.

METHODS

Forty Hy-Line W-80 laying hens were chronically exposed to sodium arsenite with a dose-dependent manner (administered with drinking water containing 10, 20, or 30 mg/L arsenic, respectively) for 42 d, followed by transcriptomics, serum non-targeted metabolome, and 16S ribosomal RNA gene sequencing accordingly.

RESULTS

Arsenic intervention induced a serious of chicken liver dysfunction, especially severe liver fibrosis, simultaneously altered ileal microbiota populations, impaired chicken intestinal barrier, further drove enterogenous lipopolysaccharides translocation via portal vein circulation aggravating liver damage. Furtherly, the injured liver disturbed bile acids (BAs) homoeostasis through strongly up-regulating the BAs synthesis key rate-limiting enzyme CYP7A1, inducing excessive serum total BAs accumulation, accompanied by the massive synthesis of primary BA-chenodeoxycholic acid. Moreover, the concentrations of secondary BAs-ursodeoxycholic acid and lithocholic acid were markedly repressed, which might involve in the repressed dehydroxylation of Ruminococcaceae and Lachnospiraceae families. Abnormal BAs metabolism in turn promoted intestinal injury, ultimately perpetuating pernicious circle in chickens. Notably, obvious depletion in the abundance of four profitable microbiota, Christensenellaceae, Ruminococcaceae, Muribaculaceae, and Faecalibacterium, were correlated tightly with this hepato-intestinal circulation process in chickens exposed to arsenic.

CONCLUSION

Our study demonstrates that chronic inorganic arsenic exposure evokes liver-microbiota-gut axis disruption in chickens and establishes a scientific basis for evaluating health risk induced by environmental pollutant arsenic.

Overexpression of FoxM1 optimizes the therapeutic effect of bone marrow mesenchymal stem cells on acute respiratory distress syndrome

BACKGROUND

Injury of alveolar epithelial cells and capillary endothelial cells is crucial in the pathogenesis of acute lung injury/acute respiratory distress syndrome (ALI/ARDS). Mesenchymal stem cells (MSCs) are a promising cell source for ALI/ARDS treatment. Overexpression of Fork head box protein M1 (FoxM1) facilitates MSC differentiation into alveolar type II (AT II) cells in vitro. Moreover, FoxM1 has been shown to repair the endothelial barrier. Therefore, this study explored whether overexpression of FoxM1 promotes the therapeutic effect of bone marrow-derived MSCs (BMSCs) on ARDS by differentiation of BMSCs into AT II cells or a paracrine mechanism.

METHODS

A septic ALI model was established in mice by intraperitoneal administration of lipopolysaccharide. The protective effect of BMSCs-FoxM1 on ALI was explored by detecting pathological variations in the lung, total protein concentration in bronchoalveolar lavage fluid (BALF), wet/dry (W/D) lung weight ratio, oxidative stress levels, cytokine levels, and retention of BMSCs in the lung. In addition, we assessed whether FoxM1 overexpression promoted the therapeutic effect of BMSCs on ALI/ARDS by differentiating into AT II cells using SPC^-/- mice. Furthermore, the protective effect of BMSCs-FoxM1 on lipopolysaccharide-induced endothelial cell (EC) injury was explored by detecting EC proliferation, apoptosis, scratch wounds, tube formation, permeability, and oxidative stress, and analyzing whether the Wnt/β-catenin pathway contributes to the regulatory mechanism in vitro using a pathway inhibitor.

RESULTS

Compared with BMSCs-Vector, treatment with BMSCs-FoxM1 significantly decreased the W/D lung weight ratio, total BALF protein level, lung injury score, oxidative stress, and cytokine levels. With the detected track of BMSCs-FoxM1, we observed a low residency rate and short duration of residency in the lung. Notably, SPC was not expressed in SPC^-/- mice injected with BMSCs-FoxM1. Furthermore, BMSCs-FoxM1 enhanced EC proliferation, migration, and tube formation; inhibited EC apoptosis and inflammation; and maintained vascular integrity through activation of the Wnt/β-catenin pathway, which was partially reversed by XAV-939.

CONCLUSION

Overexpression of FoxM1 enhanced the therapeutic effect of BMSCs on ARDS, possibly through a paracrine mechanism rather than by promoting BMSC differentiation into AT II cells in vivo, and prevented LPS-induced EC barrier disruption partially through activating the Wnt/β-catenin signaling pathway in vitro.

Visfatin Amplifies Cardiac Inflammation and Aggravates Cardiac Injury via the NF-κB p65 Signaling Pathway in LPS-Treated Mice

Background

Visfatin is an adipocytokine that has been demonstrated to be involved in cardiovascular diseases. This study aims at determining the role of visfatin in sepsis-induced cardiac injury and identify its possible mechanisms.

Methods

Dynamic changes in visfatin expression in mice with lipopolysaccharide- (LPS-) induced septicemia were measured. Additionally, mice were pretreated with visfatin and further administered LPS to observe the effects of visfatin on cardiac injury. Finally, septic mice were also pretreated with JSH-23 to investigate whether visfatin regulates cardiac injury via the NF-κB p65 pathway.

Results

Visfatin expression levels in both the heart and serum were increased in LPS-treated mice and peaked at 6 hours, and visfatin was derived from cardiac macrophages. In septic mice, pretreatment with visfatin reduced the survival rate, worsened cardiac dysfunction, and increased the expression of cardiac injury markers, including creatine kinase myocardial bound (CK-MB) and lactate dehydrogenase (LDH). Treatment with visfatin also increased the infiltration of CD3+ cells and F4/80+ cells, amplified the cardiac inflammatory response, and elevated myocardial cell apoptosis. Treatment with JSH-23 reversed the effects of visfatin in septic mice.

Conclusions

This study showed that visfatin amplifies the cardiac inflammatory response and aggravates cardiac injury through the p65 signaling pathway. Visfatin may be a clinical target for preventing cardiac injury in sepsis.

Inhibition of visfatin alleviates sepsis-induced intestinal damage by inhibiting Hippo signaling pathway

Background

The aim of this study is to investigate role of Visfatin, one of the pro-inflammatory adipokines, in sepsis-induced intestinal injury and to clarify the potential mechanism.

Methods

C57BL/6 mice underwent cecal ligation and puncture (CLP) surgery to establish sepsis model in vivo. Intestinal epithelial cells were stimulated with LPS to mimic sepsis-induced intestinal injury in vitro. FK866 (the inhibitor of Visfatin) with or without XMU-MP-1 (the inhibitor of Hippo signaling) was applied for treatment. The expression levels of Visfatin, NF-κB and Hippo signaling pathways-related proteins were detected by western blot or immunohistochemistry. The intestinal cell apoptosis and intestinal injury were investigated by TUNEL staining and H&E staining, respectively. ELISA was used to determine the production of inflammatory cytokines.

Results

The expression of Visfatin increased in CLP mice. FK866 reduced intestinal pathological injury, inflammatory cytokines production, and intestinal cell apoptosis in sepsis mice. Meanwhile, FK866 affected NF-κB and Hippo signaling pathways. Additionally, the effects of FK866 on inflammatory response, apoptosis, Hippo signaling and NF-κB signaling were partly abolished by XMU-MP-1, the inhibitor of Hippo signaling. In vitro experiments also revealed that FK866 exhibited a protective role against LPS-induced inflammatory response and apoptosis in intestinal cells, as well as regulating NF-κB and Hippo signaling, whereas addition of XMU-MP-1 weakened the protective effects of FK866.

Conclusion

In short, this study demonstrated that inhibition of Visfatin might alleviate sepsis-induced intestinal injury through Hippo signaling pathway, supporting a further research on Visfatin as a therapeutic target.

Alterations in the expression level of visfatin in the lungs of piglets infected with PRRSV and its effect on PRRSV replication

Porcine reproductive and respiratory syndrome (PRRS) is a highly contagious disease caused by PRRS virus (PRRSV), characterized by sow reproductive failure and respiratory symptoms in pigs of all ages. PRRSV mainly causes severe lung damage by invading alveolar macrophages. Visfatin is closely related to acute lung injury, immune response and inflammation along with virus invasion to the host. Therefore, the current study was performed to clarify the relationship between visfatin and PRRSV infection. We used ternary piglets to construct a piglet model to explore the expression of visfatin and tight junction protein in lung injury induced by PRRSV infection, and then further studied the inhibition effect of visfatin on PRRSV replication by PRRSV infection of Marc-145 cells. Our results indicated that both PRRSV attenuated and virulent infections could damage the lung tissues, which could not only lead to severe inflammatory reaction (such as increased expression of TNF-α, TGF-β, IL-8 and IL-10) in lung tissues of piglets, but also brought about the sharp decrease of ZO-1 and Tricellulin expressions resulting in impaired alveolar epithelial barrier. Meanwhile, we found significantly up-regulated expression of visfatin in lungs and serum of pigs after PRRSV infection that were related to both the degree of lung injury and the virulence of PRRSV strain. Moreover, visfatin might inhibit the PRRSV infection to Marc-145 cells in time dependent fashion. Hence, the current investigation provides the novel information about the effect of visfatin and PRRSV co-culture on Marc-145 cells and the effect of visfatin on PRRSV proliferation at different time points.

Anti-Inflammatory Effects of Sosiho-Tang, a Traditional Herbal Formula, on Acute Lung Injury in LPS-Sensitized Mice and -Raw 264.7 Cells

Acute lung injury (ALI) is a series of syndromes with persistent inflammation and abnormally increased vascular permeability. Sosiho-tang (SSHT), a traditional herbal formula consisting of a mixture of seven herbs, has been used to treat allergic reactions and chronic hepatitis disease in East Asia. In this study, we determined whether SSHT has an inhibitory effect against lipopolysaccharide- (LPS-) induced acute lung injury (ALI) in mice. 0.05, 0.55, and 5.55 mg/kg of SSHT were orally administered to C57BL/6J mice for 7 days prior to the administration of LPS. After 2 h of LPS sensitization, lung tissues were collected to confirm the lung histology and ALI-related inflammatory factors. SSHT ameliorated the LPS-induced alveolar hemorrhage, alveolar wall thickening, and the shrinkage of the alveolar spaces in the ALI mice model. Proinflammatory cytokines including IL-6, TNF-α, and IFN-γ in the lung tissue were significantly regulated in the SSHT-treated groups compared to the LPS only-treated group. Also, increases of IL-6 and TNF-α and decrease of IFN-γ expressions were dose-dependently modulated by SSHT treatment in LPS-induced raw 264.7 cells. Additionally, the translocation of NF-κB into nucleus and phosphorylation of mitogen-activated protein (MAP) kinase were significantly attenuated by the treatment of SSHT in LPS-sensitized ALI mice. SSHT showed anti-inflammatory activities by inhibiting proinflammatory cytokines and NF-κB signaling in LPS-induced ALI. This study demonstrates that SSHT has preventive effects on LPS-induced ALI by regulating inflammatory responses as an alternative for treating lung diseases.

Preparation and Characterization of Protein-loaded PFC Nanoemulsions for the Treatment of Heart Diseases by Pulmonary Administration

In the treatment of heart disease, strategies for the targeted delivery of protein therapeutics to the heart by inhalation are still immature. Perfluorocarbons (PFCs) are inert chemicals with good biocompatibility, and unique physico-chemical properties that have recently led to their applications in numerous fields. In this study, we combined the advantages of protein-phospholipid complexes and PFC emulsions and then synthesized protein-loaded PFC nanoemulsions (PNEs) to test whether, after inhalation, these nanoemulsions could deliver therapeutic proteins to the heart. After preparing protein-phospholipid complexes by lyophilization, we obtained PNEs by extrusion. The particle size and surface charge of PNEs were about 140 nm and -50 mV, respectively. In vitro results showed that the PNEs had a fine particle fraction of 35% and exhibited sustained protein release. Translocation studies were done using three types of pulmonary epithelial cells, and ~7% translocation was observed in the Calu-3 cell line. Further, they were easily absorbed by cells and had therapeutic effects in culture. In vivo results showed that the PNEs successfully delivered proteins to the myocardial tissue of rats and reduced ischemic myocardial injury caused by acute myocardial infarction (AMI). This study suggests that inhalation of PNEs is a new potential strategy to deliver proteins to cardiac tissues for treating heart diseases.

Optimization and bioactivity verification of porcine recombinant visfatin with high expression and low endotoxin content using pig liver as template

In order to obtain the porcine recombinant visfatin protein with high expression and low endotoxin content, the current study aims to express and verify the biological activity of the purified porcine recombinant visfatin protein. Firstly, four different expression strains were successfully constructed. Then they were simultaneously induced at 37 °C for 4 h and 16 °C for 16 h. The results showed that Visfatin-pET28a-Transetta was the best strain with high protein expression and purity at 16 °C induction for 16 h. After that, endotoxin was reduced from the recombinant visfatin until the residual endotoxin was less than one endotoxin units per milliliter (EU/mL). Finally, the purified porcine recombinant visfatin protein was incubated with RAW264.7 cells. The results of cell counting kit-8 (CCK-8) showed the survival rate of the cells first increased and then decreased with the increase in visfatin concentration. When the concentration of visfatin was 700 ng/mL, the survival rate of the cells was the highest. Thereafter, control (PBS), Visfatin and Visfatin + PolymyxinB (Ploy.B) groups were incubated with the RAW264.7 cells for 6 h. Real-time quantitative polymerase chain reaction (RT-qPCR) and Enzyme Linked Immuno-Sorbent Assay (ELISA) results showed that, as compared to the control group, the expressions of interleukin (IL)-1β, tumor necrosis factor (TNF)-α and monocyte chemoattractant protein (MCP)-1 in Visfatin group were significantly increased (P < 0.05). However, there was no significant difference between the Visfatin and Visfatin + Poly.B groups, indicating that porcine recombinant visfatin protein promoted the inflammatory activity of RAW264.7 cells while the residual endotoxin did not play a role, suggesting biological activity of porcine recombinant visfatin protein.

TLR4-MyD88 signaling pathway is responsible for acute lung inflammation induced by reclaimed water

Previous research found that inhalation exposure of reclaimed water could cause severe pulmonary inflammation, and the endotoxin was proposed to be the key risk factor. To further support this view, the toxic effects of different reclaimed water induced by acute inhalation exposure were compared between wildtype C57BL/6J and TLR4 signaling pathway defect mice. It was found that reclaimed water with high levels of endotoxin could induce strong inflammation in wildtype mice, but not in Tlr4^-/- and MyD88^-/- mutants. The mixed bacterial culture from the reclaimed water showed very weak response in wildtype mice and no response in TLR4-signaling pathway deficient mice, which further suggested that the cell-bound endotoxins contribute little in the inflammation induced by reclaimed water. In addition, conditional knockout of the Tlr4 gene in myeloid cells resulted in a significant reduction of sensitivity to the reclaimed water in mutants, which indicates that myeloid cells play the most important role in the defensive immune system against the pollutants in the water. In general, this study demonstrated that the TLR4-MyD88 signaling pathway is responsible for the acute lung inflammation induced by reclaimed water, which excludes the possibility of other signaling pathway dependent inflammation inducers in reclaimed water.