p38α in macrophages aggravates arterial endothelium injury by releasing IL-6 through phosphorylating megakaryocytic leukemia 1

Phosphatidic acid-enabled MKL1 contributes to liver regeneration: Translational implication in liver failure

Liver regeneration following injury aids the restoration of liver mass and the recovery of liver function. In the present study we investigated the contribution of megakaryocytic leukemia 1 (MKL1), a transcriptional modulator, to liver regeneration. We report that both MKL1 expression and its nuclear translocation correlated with hepatocyte proliferation in cell and animal models of liver regeneration and in liver failure patients. Mice with MKL1 deletion exhibited defective regenerative response in the liver. Transcriptomic analysis revealed that MKL1 interacted with E2F1 to program pro-regenerative transcription. MAPKAPK2 mediated phosphorylation primed MKL1 for its interaction with E2F1. Of interest, phospholipase d2 promoted MKL1 nuclear accumulation and liver regeneration by catalyzing production of phosphatidic acid (PA). PA administration stimulated hepatocyte proliferation and enhanced survival in a MKL1-dependent manner in a pre-clinical model of liver failure. Finally, PA levels was detected to be positively correlated with expression of pro-regenerative genes and inversely correlated with liver injury in liver failure patients. In conclusion, our data reveal a novel mechanism whereby MKL1 contributes to liver regeneration. Screening for small-molecule compounds boosting MKL1 activity may be considered as a reasonable approach to treat acute liver failure.

Omentin-1 enhances the inhibitory effect of endothelial progenitor cells on neointimal hyperplasia by inhibiting the p38 MAPK/CREB pathway

AIMS

Endothelial progenitor cells (EPCs) play an important role in vascular repair. However, they are dysfunctional in the inflammatory microenvironment during restenosis. In this study, we investigated whether omentin-1, an anti-inflammatory factor, could reduce neointima formation after carotid artery injury (CAI) in rats by improving EPC functions that were damaged by inflammation and the underlying mechanisms.

MAIN METHODS

EPCs were transfected with adenoviral vectors expressing human omentin-1 or green fluorescent protein (GFP). Then, the rats received 2 × 106 EPCs expressing omentin-1 or GFP by tail vein injection directly after CAI and again 24 h later. Hematoxylin-eosin staining and immunohistochemistry were used for analyzing neointimal hyperplasia. Besides, EPCs were treated with omentin-1 and TNF-α to examine the underlying mechanism.

KEY FINDINGS

Our results showed that omentin-1 could significantly improve EPC functions, including proliferation, apoptosis and tube formation. Meanwhile, EPCs overexpressed with omentin-1 could significantly reduce neointimal hyperplasia and tumor necrosis factor-α (TNF-α) expression after CAI in rats. TNF-α could notably induce EPC dysfunction, which could be markedly reversed by omentin-1 through the inhibition of the p38 MAPK/CREB pathway. Furthermore, a p38 MAPK agonist (anisomycin) significantly abrogated the protective effects of omentin-1 on EPCs damaged by TNF-α.

SIGNIFICANCE

Our results indicated that genetically modifying EPC with omentin-1 could be an alternative strategy for the treatment of restenosis.

MEGF6 prevents sepsis-induced acute lung injury in mice

OBJECTIVE

Acute lung injury (ALI) is featured as excessive inflammatory response and oxidative damage, and results in high death rate of septic patients. This research intends to determine the function of multiple EGF like domains 6 (MEGF6) in sepsis-induced ALI.

METHODS

Mice were intratracheally treated with adenovirus to knock down or overexpress MEGF6 in lung tissues, and then were subjected to cecum ligation and puncture (CLP) operation to induce ALI. Primary peritoneal macrophages were isolated, and were knocked down or overexpressed with MEGF6, and then, were stimulated with lipopolysaccharide (LPS) to confirm its role in vitro.

RESULTS

Serum and lung MEGF6 levels were significantly elevated in septic mice. MEGF6 knockdown exacerbated, while MEGF6 overexpression prevented inflammation, oxidative damage and ALI in CLP mice. Meanwhile, LPS-elicited inflammatory response and oxidative damage in primary macrophages were reduced by MEGF6 overexpression, but were further aggravated by MEGF6 knockdown. Mechanistic studies revealed that MEGF6 reduced cluster of differentiation 38 (CD38) expression and subsequently elevated intracellular nicotinamide adenine dinucleotide levels, thereby activating sirtuin 1 (SIRT1) without affecting the protein expression. SIRT1 suppression or CD38 overexpression with either genetic or pharmacologic methods remarkably blunted the lung protective effects of MEGF6 in CLP mice.

CONCLUSION

MEGF6 prevents CLP-induced ALI through CD38/SIRT1 pathway, and it might be a valuable therapeutic candidate for the management of sepsis-induced ALI.

Effects and Potential Mechanism of Zhuyu Pill Against Atherosclerosis: Network Pharmacology and Experimental Validation

Background

Atherosclerosis (AS) is an immunoinflammatory disease associated with dyslipidemia. Zhuyu Pill (ZYP) is a classic Chinese herbal compound that has been shown to exhibit anti-inflammatory and lipid-lowering effects on AS in our previous studies. However, the underlying mechanisms by which ZYP ameliorates atherosclerosis have not yet been fully investigated. In this study, network pharmacology and in vivo experiments were conducted to explore the underlying pharmacological mechanisms of ZYP on ameliorating AS.

Methods

The active ingredients of ZYP were acquired from our previous study. The putative targets of ZYP relevant to AS were obtained from TCMSP, SwissTargetPrediction, STITCH, DisGeNET, and GeneCards databases. Protein-protein interactions (PPI) network, Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were conducted using the Cytoscape software. Furthermore, in vivo experiments were carried out for target validation in apolipoprotein E (ApoE) -/- mice.

Results

Animal experiments revealed that ZYP ameliorated AS mainly through lowering blood lipids, alleviating vascular inflammation, and decreasing the levels of vascular cell adhesion molecule-1 (VCAM1), intercellular adhesion molecule-1 (ICAM1), monocyte chemotactic protein-1 (MCP-1), interleukin 6 (IL-6), and tumor necrosis factor-α (TNF-α). Additionally, the results of Real-Time quantitative PCR revealed that ZYP inhibited the gene expressions of mitogen-activated protein kinase (MAPK) p38, extracellular regulated protein kinases (ERK), c-Jun N-terminal kinase (JNK), and nuclear factor kappa-B (NF-κB) p65. The Immunohistochemistry and Western blot assays showed the inhibitory effect of ZYP on the proteins level of p38, p-p38, p65, and p-p65.

Conclusion

This study has provided valuable evidence on the pharmacological mechanisms of action of ZYP in ameliorating AS that will be useful for forming the rationale of future research studying the cardio-protection and anti-inflammation effects of ZYP.

Mechanism of Tao Hong Decoction in the treatment of atherosclerosis based on network pharmacology and experimental validation

Background

Atherosclerosis (AS) has long been recognized as a cardiovascular disease and stroke risk factor. A well-known traditional Chinese medicine prescription, Tao Hong decoction (THD), has been proven effective in treating AS, but its mechanism of action is still unclear.

Objective

To assess the effects, explore THD's primary mechanism for treating AS, and provide a basis for rational interpretation of its prescription compatibility.

Methods

Based on network pharmacology, we evaluated the mechanism of THD on AS by data analysis, target prediction, the construction of PPI networks, and GO and KEGG analysis. AutoDockTools software to conduct Molecular docking. Then UPLC-Q-TOF-MS was used to identify significant constituents of THD. Furthermore, an AS mice model was constructed and intervened with THD. Immunofluorescence, RT-qPCR, and Western blot were used to verify the critical targets in animal experiments.

Results

The network pharmacology results indicate that eight core targets and seven core active ingredients play an essential role in this process. The GO and KEGG analysis results suggested that the mechanism is mainly involved in Fluid shear stress and atherosclerosis and Lipid and atherosclerosis. The molecular docking results indicate a generally strong affinity. The animal experiment showed that THD reduced plaque area, increased plaque stability, and decreased the levels of inflammatory cytokines (NF-κB, IL-1α, TNF-α, IL-6, IL-18, IL-1β) in high-fat diet -induced ApoE-/-mice. Decreased levels of PTGS2, HIF-1α, VEGFA, VEGFC, FLT-4, and the phosphorylation of PI3K, AKT, and p38 were detected in the THD-treated group.

Conclusion

THD plays a vital role in treating AS with multiple targets and pathways. Angiogenesis regulation, oxidative stress regulation, and immunity regulation consist of the crucial regulation cores in the mechanism. This study identified essential genes and pathways associated with the prognosis and pathogenesis of AS from new insights, demonstrating a feasible method for researching THD's chemical basis and pharmacology.

Quantitative phosphoproteomic analysis of mice with liver fibrosis by DIA mass spectrometry analysis with PRM verification

Liver fibrosis (LF), commonly associated with chronic liver diseases, is a major public health problem worldwide. Protein phosphorylation is not only an important form of protein modification in organisms but also the most important mechanism to regulate and control the activity and function of proteins, affecting the occurrence and development of many diseases. However, comprehensive phosphoproteomic profiling in LF has not been fully elucidated. In this study, data-independent acquisition (DIA) was used to analyse the phosphoproteomics of mice with LF. A total of 553 phosphopeptides (representing 440 phosphoproteins) had significant phosphorylation levels. Among these phosphoproteins, 49 were upregulated and 401 were downregulated, and 5 phosphoserine (P-Ser) motifs and 2 phosphothreonine (P-Thr) motifs were conserved in LF. GO and KEGG pathway enrichment analyses identified 769 significant GO terms and 49 significant KEGG pathways. Four phosphorylated proteins were selected for parallel reaction monitoring (PRM) verification, and the results were consistent with DIA data. Together, there were significantly different phosphoproteomic profiles in LF, suggesting that protein phosphorylation was related to the occurrence and progression of LF, which could pave the way for further investigation into the related regulatory mechanisms. SIGNIFICANCE: LF is a necessary stage in the development of chronic liver disease to liver cirrhosis and has attracted wide attention. To the best of our knowledge, there are few reports on the phosphorylated proteomics of LF. In this study, DIA and PRM techniques were used to study the liver tissue of mice induced by CCl₄. The results showed that phosphorylation had a significant effect on the activity and function of proteins, and the PRM results were consistent with the trend observed in DIA analysis. This study will help to better reveal the relationship of phosphorylated proteins in LF and lay a foundation for further study of related regulatory mechanisms.

MKL1 fuels ROS-induced proliferation of vascular smooth muscle cells by modulating FOXM1 transcription

Reactive oxygen species (ROS) promotes vascular injury and neointima formation in part by stimulating proliferation of vascular smooth muscle cells (VSMC). The underlying transcriptional mechanism, however, is not completely understood. Here we report that VSMC-specific deletion of MKL1 in mice suppressed neointima formation in a classic model of vascular injury. Likewise, pharmaceutical inhibition of MKL1 activity by CCG-1423 similarly mollified neointima formation in mice. Over-expression of a constitutively active MKL1 in vascular smooth muscle cells enhanced proliferation in a ROS-dependent manner. On the contrary, MKL1 depletion or inhibition attenuated VSMC proliferation. PCR array based screening identified forkhead box protein M1 (FOXM1) as a direct target for MKL1. MKL1 interacted with E2F1 to activate FOXM1 expression. Concordantly, FOXM1 depletion ameliorated MKL1-dependent VSMC proliferation. Of interest, ROS-induced MKL1 phosphorylation through MK2 was essential for its interaction with E2F1 and consequently FOXM1 trans-activation. Importantly, a positive correlation between FOXM1 expression and VSMC proliferation was identified in arterial specimens from patients with restenosis. Taken together, our data suggest that a redox-sensitive phosphorylation-switch of MKL1 activates FOXM1 transcription and mediates ROS fueled vascular smooth muscle proliferation. Targeting the MK-2/MKL1/FOXM1 axis may be considered as a reasonable approach for treatment of restenosis.

Progress of Research into the Interleukin-1 Family in Cardiovascular Disease

Inflammatory factors, such as the IL-1 family, are generally acknowledged to be involved in systemic diseases and IL-1α and IL-1β, in particular, have been linked to cardiovascular disease with IL-18, IL-33, IL-36, IL-37 and IL-38 yet to be explored. The current review aims to summarize mechanisms of IL-18, IL-33, IL-36, IL-37 and IL-38 in myocardial infarction, hypertension, arrhythmia, valvular disease and aneurysm and to explore the potential for cardiovascular disease treatment strategies and discuss future directions for prevention and treatment.

MRTF may be the missing link in a multiscale mechanobiology approach toward macrophage dysfunction in space

Macrophages exhibit impaired phagocytosis, adhesion, migration, and cytokine production in space, hindering their ability to elicit immune responses. Considering that the combined effect of spaceflight microgravity and radiation is multiscale and multifactorial in nature, it is expected that contradictory findings are common in the field. This theory paper reanalyzes research on the macrophage spaceflight response across multiple timescales from seconds to weeks, and spatial scales from the molecular, intracellular, extracellular, to the physiological. Key findings include time-dependence of both pro-inflammatory activation and integrin expression. Here, we introduce the time-dependent, intracellular localization of MRTF-A as a hypothetical confounder of macrophage activation. We discuss the mechanosensitive MRTF-A/SRF pathway dependence on the actin cytoskeleton/nucleoskeleton, microtubules, membrane mechanoreceptors, hypoxia, oxidative stress, and intracellular/extracellular crosstalk. By adopting a multiscale perspective, this paper provides the first mechanistic answer for a three-decade-old question regarding impaired cytokine secretion in microgravity—and strengthens the connection between the recent advances in mechanobiology, microgravity, and the spaceflight immune response. Finally, we hypothesize MRTF involvement and complications in treating spaceflight-induced cardiovascular, skeletal, and immune disease.

Bovine serum albumin-based biomimetic gene complexes with specificity facilitate rapid re-endothelialization for anti-restenosis

Re-endothelialization is a critical problem to inhibit postoperative restenosis, and gene delivery exhibits great potential in rapid endothelialization. Unfortunately, the therapeutic effect is enormously limited by inefficient specificity, poor biocompatibility and in vivo stability owing largely to the complicated in vivo environment. Herein, we developed a series of platelet membrane (PM) cloaked gene complexes based on natural bovine serum albumin (BSA) and polyethyleneimine (PEI). The gene complexes aimed to accelerate re-endothelialization for anti-restenosis via pcDNA3.1-VEGF165 (VEGF) plasmid delivery. Based on BSA and PM coating, these gene complexes exhibited good biocompatibility, stability with serum and robust homing to endothelium-injured site inherited from platelets. Besides, they enhanced the expression of VEGF protein by their high internalization and nucleus accumulation efficiency, and also substantially promoted migration and proliferation of vascular endothelial cells. The biological properties were further optimized via altering PEI and PM content. Finally, rapid recovery of endothelium in a carotid artery injured mouse model (79% re-endothelialization compared with model group) was achieved through two weeks' treatment by the PM cloaked gene complexes. High level of expressed VEGF in vivo was also realized by the gene complexes. Moreover, neointimal hyperplasia (IH) was significantly inhibited by the gene complexes according to in vivo study. The results verified the great potential of the PM cloaked gene complexes in re-endothelialization for anti-restenosis. STATEMENT OF SIGNIFICANCE: Rapid re-endothelialization is a major challenge to inhibit postoperative restenosis. Herein, a series of biodegradable and biocompatible platelet membrane (PM) cloaked gene complexes were designed to accelerate re-endothelialization for anti-restenosis via pcDNA3.1-VEGF165 (VEGF) plasmid delivery. The PM cloaked gene complexes provided high VEGF expression in vascular endothelial cells (VECs), rapid migration and proliferation of VECs and robust homing to endothelium-injured site. In a carotid artery injured mouse model, PM cloaked gene complexes significantly promoted VEGF expression in vivo, accelerated re-endothelialization and inhibited neointimal hyperplasia due to their good biocompatibility and superior specificity. Overall, the optimized PM cloaked gene complexes overcomes multiple obstacles in gene delivery for re-endothelialization and can be a promising candidate for gene delivery and therapy of postoperative restenosis.

IMP3 promotes re-endothelialization after arterial injury via increasing stability of VEGF mRNAhv

IMP3, an RNA‐binding protein (RBP) that participates in the process of post‐transcriptional modifications of mRNA transcripts, is capable of altering cellular functions, and in some cases, be involved in specific disease progression. We aimed to investigate whether IMP3 has the ability to regulate the functional properties of endothelial cells and re‐endothelialization in response to arterial injury. Wire injury was introduced to the right carotid arteries of wildtype C57/BL6 mice. As a result, IMPs’ expressions were up‐regulated in the induced arterial lesions, and IMP3 was the most up‐regulated RNA among other IMPs. We overexpressed IMP3 before the wire‐injured surgery using adeno‐associated virus AAV2‐IMP3. In vivo studies confirmed that IMP3 overexpression accelerated the progress of re‐endothelialization after arterial injury. In vitro, endothelial cells were transfected with either ad‐IMP3 or Si‐IMP3, cell functional studies showed that IMP3 could promote endothelial cell proliferation and migration, while reducing apoptosis. Mechanistic studies also revealed that IMP3 could enhance VEGF mRNA stability and therefore up‐regulate activities of VEGF/PI3K/Akt signalling pathway. Our data indicated that IMP3 promotes re‐endothelialization after arterial injury and regulates endothelial cell proliferation, migration and apoptosis via increasing stability of VEGF mRNA and activation of VEGF/PI3K/Akt signalling pathway.

Skin wound healing promoted by novel curcumin-loaded micelle hydrogel

Background

The development of biomaterials with the ability to promote skin wound healing is an important topic in the field of biomedical science. In this study, a topical curcumin (Cur) gel [Cur/hyaluronic acid (HA)] was prepared by combining curcumin-loaded PCL-b-PEG-b-PCL (PECE) nanomicelles (PCEC/Cur) and HA to effectively promote skin wound healing. Continuous drug release from PCEC/Cur can provide long-term protection and treatment of skin wounds.

Methods

The study was completed in two stages. The first stage (in vitro): PCEC/Cur were prepared by thin film hydration method. The second stage (in vivo): 36 anesthetized rats were used to prepare a round full-thickness skin defect wound with a diameter of 23 mm on the dorsal side of the spine, and the rats were randomly divided into 4 groups with 9 rats in each group.

Results

The results showed that wounds in the Cur/HA group were restored to normal after 14 days after operation, representing 96%±3% wound healing. Hematoxylin and eosin (HE) staining showed that hair follicles in the Cur/HA group were visible and that the re-epithelialization time was earlier. Masson staining showed that Cur/HA promoted the formation of collagen fibers. Immunohistochemical observation showed that angiogenesis and subsequent healing of the wound surface was enhanced in the Cur/HA group.

Conclusions

The injectable hyaluronic acid gel complex Cur/HA is a promising candidate material for a wound dressing to promote healing.