Ginsenoside Rb1 ameliorates lipopolysaccharide-induced albumin leakage from rat mesenteric venules by intervening in both trans- and paracellular pathway

Ginsenoside Rb1 prevents age-related endothelial senescence by modulating SIRT1/caveolin-1/enos signaling pathway

Background

Advancing age is one of the independent risk factors for cardiovascular disorders. The Compendium of Materia Medica, a classic book on traditional Chinese medicine, states that ginseng "harmonizes the five internal organs, calming the spirit and prolonging the years of life." Considered one of the primary bioactive compounds derived from Panax ginseng, ginsenoside Rb1 (g-Rb1) has been scientifically suggested to possess anti-senescence efficacy. More research is needed to explore the vascular pharmacological activity and potential clinical application value of g-Rb1.

Aims of the study

Our previous study demonstrated that g-Rb1 could mitigate cellular senescence via the SIRT1/eNOS pathway. This study was performed to explore the exact mechanisms by which g-Rb1 modulates the SIRT1/eNOS pathway.

Materials and methods

We used human primary umbilical vein endothelial cells (HUVECs) to establish a replicative ageing model. Real-time (RT‒PCR), western blotting, small interfering RNA (siRNA), and immunoprecipitation were conducted to detect the effect of g-Rb1 on the SIRT1/caveolin-1/eNOS axis.

Results

G-Rb1 increased NO production and alleviated replicative senescence of HUVECs. The application of g-Rb1 elevated the mRNA and protein abundance of both SIRT1 and eNOS while concomitantly suppressing the expression of caveolin-1. Inhibition of SIRT1 and eNOS by siRNAs suppressed the anti-senescence function of g-Rb1, while caveolin-1 siRNA could enhance it. G-Rb1 decreased the acetylation level of caveolin-1 and increased NO production, which was suppressed by SIRT1 siRNA. Both g-Rb1 and caveolin-1 siRNA could reduce the acetylation level of eNOS and increase NO production.

Conclusion

G-Rb1 prevents age-related endothelial senescence by modulating the SIRT1/caveolin-1/eNOS signaling pathway.

Recent Advances in Biologically Active Ingredients from Natural Drugs for Sepsis Treatment

Sepsis refers to the dysregulated host response to infection; its incidence and mortality rates are high. It is a worldwide medical problem but there is no specific drug for it. In recent years, clinical and experimental studies have found that many monomer components of traditional Chinese medicine have certain effects on the treatment of sepsis. This paper reviews the advances in research on the active ingredients of traditional Chinese medicine involved in the treatment of sepsis in recent years according to their chemical structure; it could provide ideas and references for further research and development in Chinese materia medica for the treatment of sepsis.

Yue-bi-tang attenuates adriamycin-induced nephropathy edema through decreasing renal microvascular permeability via inhibition of the Cav-1/ eNOS pathway

Edema is one of the most typical symptoms of nephrotic syndrome. Increased vascular permeability makes a significant contribution to the progression of edema. Yue-bi-tang (YBT) is a traditional formula with excellent clinical efficacy in the treatment of edema. This study investigated the effect of YBT on renal microvascular hyperpermeability-induced edema in nephrotic syndrome and its mechanism. In our study, the content of target chemical components of YBT was identified using UHPLC-Q-Orbitrap HRMS analysis. A nephrotic syndrome model was replicated based on male Sprague-Dawley rats with Adriamycin (6.5 mg/kg) by tail vein injection. The rats were randomly divided into control, model, prednisone, and YBT (22.2 g/kg, 11.1 g/kg, and 6.6 g/kg) groups. After 14 d of treatment, the severity of renal microvascular permeability, edema, the degree of renal injury, and changes in the Cav-1/eNOS pathway were assessed. We found that YBT could regulate renal microvascular permeability, alleviate edema, and reduce renal function impairment. In the model group, the protein expression of Cav-1 was upregulated, whereas VE-cadherin was downregulated, accompanied by the suppression of p-eNOS expression and activation of the PI3K pathway. Meanwhile, an increased NO level in both serum and kidney tissues was observed, and the above situations were improved with YBT intervention. It thus indicates YBT exerts therapeutic effects on the edema of nephrotic syndrome, as it improves the hyperpermeability of renal microvasculature, and that YBT is engaged in the regulation of Cav-1/eNOS pathway-mediated endothelial function.

The relationship of skin disorders, COVID-19, and the therapeutic potential of ginseng: a review

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has made significant impacts on global public health, including the development of several skin diseases that have arisen primarily as a result of the pandemic. Owing to the widespread expansion of coronavirus disease 19 (COVID-19), the development of effective treatments for these skin diseases is drawing attention as an important social issue. For many centuries, ginseng and its major active ingredients, ginsenosides and saponins, have been widely regarded as herbal medicines. Further, the anti-viral action of ginseng suggests its potential effectiveness as a therapeutic agent against COVID-19. Thus, the aim of this review was to examine the association of skin lesions with COVID-19 and the effect of ginseng as a therapeutic agent to treat skin diseases induced by COVID-19 infection. We classified COVID-19-related skin disorders into three categories: caused by inflammatory, immune, and complex (both inflammatory and immune) responses and evaluated the evidence for ginseng as a treatment for each category. This review offers comprehensive evidence on the improvement of skin disorders induced by SARS-CoV-2 infection using ginseng and its active constituents.

The hepatoprotective effects of plant-based foods based on the "gut-liver axis": a prospective review

The importance of the "gut-liver axis" in the pathogenesis of liver diseases has been revealed recently; which promotes the process of developing preventive and therapeutic strategies. However, considering that there are still many challenges in the medical treatment of liver diseases, potential preventive dietary intervention may be a good alternative choice. Plant-based foods have received much attention due to their reported health-promoting effects in targeting multiple pathways involved in the pathogenesis of liver diseases as well as the relative safety for general use. Based on the PubMed and Web of Science databases, this review emphatically summarizes the plant-based foods and their chemical constituents with reported effects to impact the LPS/TLR4 signaling pathway of gut-liver axis of various liver diseases, reflecting their health benefits in preventing/alleviating liver diseases. Moreover, some plant-based foods with potential gut-liver effects are specifically analyzed from the reported studies and conclusions. This review intends to provide readers an overview of the current progress in the field of this research topic. We expect to see more hepatoprotective measures for alleviating the current prevalence of liver diseases.

Ginseng in vascular dysfunction: A review of therapeutic potentials and molecular mechanisms

Vascular dysfunction can lead to a variety of fatal diseases, including cardiovascular and cerebrovascular diseases, metabolic syndrome, and cancer. Although a large number of studies have reported the therapeutic effects of natural compounds on vascular‐related diseases, ginseng is still the focus of research. Ginseng and its active substances have bioactive effects against different diseases with vascular dysfunction. In this review, we summarized the key molecular mechanisms and signaling pathways of ginseng, its different active ingredients or formula in the prevention and treatment of vascular‐related diseases, including cardiac‐cerebral vascular diseases, hypertension, diabetes complications, and cancer. Moreover, the bidirectional roles of ginseng in promoting or inhibiting angiogenesis have been highlighted. We systematically teased out the relationship between ginseng and vascular dysfunction, which could provide a basis for the clinical application of ginseng in the future.

Ginseng in vascular dysfunction: A review of therapeutic potentials and molecular mechanisms

Vascular dysfunction can lead to a variety of fatal diseases, including cardiovascular and cerebrovascular diseases, metabolic syndrome, and cancer. Although a large number of studies have reported the therapeutic effects of natural compounds on vascular-related diseases, ginseng is still the focus of research. Ginseng and its active substances have bioactive effects against different diseases with vascular dysfunction. In this review, we summarized the key molecular mechanisms and signaling pathways of ginseng, its different active ingredients or formula in the prevention and treatment of vascular-related diseases, including cardiac-cerebral vascular diseases, hypertension, diabetes complications, and cancer. Moreover, the bidirectional roles of ginseng in promoting or inhibiting angiogenesis have been highlighted. We systematically teased out the relationship between ginseng and vascular dysfunction, which could provide a basis for the clinical application of ginseng in the future.

Clinical value of serum calcium in elderly patients with sepsis

PURPOSE

To explore the clinical value of serum calcium (Ca) in elderly patients with sepsis.

MATERIALS AND METHODS

The clinical data and laboratory data of elderly patients with sepsis (n = 165) and elderly population for physical examination (n = 67) in a tertiary hospital from January 2020 to November 2020 were collected. We analyzed serum Ca levels in sepsis and septic shock firstly, and then continued to investigate them in the survival group and the death group. Meanwhile, we also assessed the correlation between serum Ca and PCT.

RESULTS

The serum Ca levels of the elderly patients with sepsis were lower than that of the control group (median 1.98 vs 2.31 mmol/L, P < 0.001), and the more severe the sepsis, the lower the serum Ca levels. Sepsis patients with decreased serum Ca had higher shock rate and mortality. There was a negative correlation between serum Ca and PCT (r = -0.2957, P < 0.001).

CONCLUSION

Serum Ca has a certain value for the early recognition of elderly patients with sepsis and the judgment of the severity of the disease.

Research Progress in Chinese Herbal Medicines for Treatment of Sepsis: Pharmacological Action, Phytochemistry, and Pharmacokinetics

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection; the pathophysiology of sepsis is complex. The incidence of sepsis is steadily increasing, with worldwide mortality ranging between 30% and 50%. Current treatment approaches mainly rely on the timely and appropriate administration of antimicrobials and supportive therapies, but the search for pharmacotherapies modulating the host response has been unsuccessful. Chinese herbal medicines, i.e., Chinese patent medicines, Chinese herbal prescriptions, and single Chinese herbs, play an important role in the treatment of sepsis through multicomponent, multipathway, and multitargeting abilities and have been officially recommended for the management of COVID-19. Chinese herbal medicines have therapeutic actions promising for the treatment of sepsis; basic scientific research on these medicines is increasing. However, the material bases of most Chinese herbal medicines and their underlying mechanisms of action have not yet been fully elucidated. This review summarizes the current studies of Chinese herbal medicines used for the treatment of sepsis in terms of clinical efficacy and safety, pharmacological activity, phytochemistry, bioactive constituents, mechanisms of action, and pharmacokinetics, to provide an important foundation for clarifying the pathogenesis of sepsis and developing novel antisepsis drugs based on Chinese herbal medicines.

A Network Pharmacology Approach for Exploring the Mechanisms of Panax notoginseng Saponins in Ischaemic Stroke

BACKGROUND

Panax notoginseng saponins (PNS) have been deemed effective herb compounds for treating ischaemic stroke (IS) and improving the quality of life of IS patients. This study aimed to investigate the underlying mechanisms of PNS in the treatment of IS based on network pharmacology.

METHODS

PNS were identified from the Traditional Chinese Medicine System Pharmacology (TCMSP) database, and their possible targets were predicted using the PharmMapper database. IS-related targets were identified from the GeneCards database, OMIM database, and DisGeNET database. A herb-compound-target-disease network was constructed using Cytoscape, and protein-protein interaction (PPI) networks were established with STRING. GO enrichment and KEGG pathway analysis were performed using DAVID. The binding of the compounds and key targets was validated by molecular docking studies using AutoDock Vina. The neuroprotective effect of TFCJ was substantiated in terms of oxidative stress (superoxide dismutase, glutathione peroxidase, catalase, and malondialdehyde) and the levels of IGF1/PI3K/Akt pathway proteins.

RESULTS

A total of 375 PNS targets and 5111 IS-related targets were identified. Among these targets, 241 were common to PNS, and IS network analysis showed that MAPK1, AKT1, PIK3R1, SRC, MAPK8, EGFR, IGF1, HRAS, RHOA, and HSP90AA1 are key targets of PNS against IS. Furthermore, GO and KEGG enrichment analysis indicated that PNS probably exert therapeutic effects against IS by regulating many pathways, such as the Ras, oestrogen, FoxO, prolactin, Rap1, PI3K-Akt, insulin, PPAR, and thyroid hormone signalling pathways. Molecular docking studies further corroborated the experimental results.The network pharmacology results were further verified by molecular docking and in vivo experiments.

CONCLUSIONS

The ameliorative effects of PNS against IS were predicted to be associated with the regulation of the IGF1-PI3K-Akt signalling pathway. Ginsenoside Re and ginsenoside Rb1 may play an important role in the treatment of IS.

Post-treatment with yiqifumai injection and its main ingredients attenuates lipopolysaccharide-induced microvascular disturbance in mesentery and ileum

OBJECTIVE

To investigate the effect of Yiqifumai injection (YQFM), a compound Chinese medicine, and its main active ingredients on lipopolysaccharide (LPS)-induced microvascular disturbance in mesentery and ileum.

METHODS

Rats were infused with LPS (5 mg/kg/h) for 90 min. Thirty minutes after initiation of LPS administration, YQFM (160 mg/kg/h), Rb1 (5 mg/kg/h), Sch (2.5 mg/kg/h), or Rb1+Sch (5 mg/kg/h + 2.5 mg/kg/h) was infused until 90 min. Human umbilical vein endothelial cells (HUVECs) were incubated with LPS (100 ng/ml) for 90 min. YQFM (1 mg/ml), Rb1 (100 µM), Sch (100 µM), or Rb1+Sch (200 µM) was added 30 min after initiation of LPS stimulation.

RESULTS

Yiqifumai injection and Rb1+Sch inhibited mesenteric venule hyperpermeability, suppressed microvillar erosion and submucosal edema, and protected claudin-5 from downregulation and interleukin-1β from upregulation in ileal tissues after LPS. Study in HUVECs confirmed the effect of YQFM and Rb1+Sch on JAM-1 after LPS and revealed a similar effect on other junction proteins. Moreover, YQFM and Rb1+Sch attenuated the dysfunctional energy metabolism and the activation of TLR-4/Src/NF-κB signaling with Rb1 and Sch being partially effective.

CONCLUSION

These results demonstrated the beneficial effect of post-treatment with YQFM, which is attributable to its main ingredient Rb1 and Sch, and likely mediated by targeting TLR-4/Src/NF-κB signaling pathway.

Advances in research into the mechanisms of Chinese Materia Medica against acute lung injury

Acute lung injury (ALI) is a common and serious disease. Numerous treatment options are available but they do not improve quality of life or reduce mortality for ALI patients. Here, we review the treatments for ALI to provide basic data for ALI drug therapy research and development. Chinese Materia Medica (CMM) has long been the traditional clinical approach in China for the treatment of ALI and it has proven efficacy. The continued study of CMM has disclosed new potential therapeutic ingredients for ALI. However, few reviews summarize the currently available CMM-based anti-ALI drugs. Therefore, the systematic analysis of research progress in anti-ALI CMM is of great academic and clinical value. The aim of the present review is to describe CMM-based research progress in ALI treatment. Data were compiled by electronic retrieval (CNKI, SciFinder, PubMeds, Google Scholar, Web of Science) and from articles, patents and ethnopharmacological literature in university libraries were systematically studied. This review introduces progress in research on the etiology and mechanisms of ALI, the anti-ALI theory and modes of action in traditional Chinese medicine (TCM), anti-ALI active constituents of CMM, research progress in experimental methods of CMM anti-ALI, the anti-ALI molecular mechanisms of CMM, the anti-ALI efficacy of CMM formulae, and the potential toxicity of CMM and the antidotes for it. Scholars have investigated the anti-ALI molecular mechanism of CMM from various direction and have made substantial progress. This research explored the above aspects, enriched the anti-ALI theory of CMM and established the clinical significance and developmental prospects of ALI treatment by CMM. Because of the high frequency of drugs such as glucocorticoids or antibiotics, Western medicine lacks the advantages of CMM in terms of overall anti-ALI efficacy. In the future, the development of CMM-based anti-ALI therapies will become a major trend in the field of ALI drug development. Successful clinical safety and efficacy validations will promote and encourage the use of CMM. It provides fundamental theoretical support for the discovery and use of CMM resources through the comprehensive analysis of various anti-ALI CMM report databases.

Post-treatment With Qing-Ying-Tang, a Compound Chinese Medicine Relives Lipopolysaccharide-Induced Cerebral Microcirculation Disturbance in Mice

Objective: Lipopolysaccharide (LPS) causes microvascular dysfunction, which is a key episode in the pathogenesis of endotoxemia. This work aimed to investigate the effect of Qing-Ying-Tang (QYT), a compound Chinese medicine in cerebral microcirculation disturbance and brain damage induced by LPS.

Methods: Male C57/BL6 mice were continuously transfused with LPS (7.5 mg/kg/h) through the left femoral vein for 2 h. QYT (14.3 g/kg) was given orally 2 h after LPS administration. The dynamics of cerebral microcirculation were evaluated by intravital microscopy. Brain tissue edema was assessed by brain water content and Evans Blue leakage. Cytokines in plasma and brain were evaluated by flow cytometry. Confocal microscopy and Western blot were applied to detect the expression of junction and adhesion proteins, and signaling proteins concerned in mouse brain tissue.

Results: Post-treatment with QYT significantly ameliorated LPS-induced leukocyte adhesion to microvascular wall and albumin leakage from cerebral venules and brain tissue edema, attenuated the increase of MCP-1, MIP-1α, IL-1α, IL-6, and VCAM-1 in brain tissue and the activation of NF-κB and expression of MMP-9 in brain. QYT ameliorated the downregulation of claudin-5, occludin, JAM-1, ZO-1, collagen IV as well as the expression and phosphorylation of VE-cadherin in mouse brain.

Conclusions: This study demonstrated that QYT protected cerebral microvascular barrier from disruption after LPS by acting on the transcellular pathway mediated by caveolae and paracellular pathway mediated by junction proteins. This result suggests QYT as a potential strategy to deal with endotoxemia.

Cardiotonic Pills Plus Recombinant Human Prourokinase Ameliorates Atherosclerotic Lesions in LDLR-/- Mice

Aim

This study was to explore the protective effects of cardiotonic pills (CP) or/and recombinant human prourokinase (proUK)on the atherosclerosis and the potential underlying mechanism.

Methods and Results

Atherosclerosis was induced in LDLR^–/^– mice by high fat diet contained 20% lard and 0.5% cholesterol. Daily oral administration of CP (130 mg/kg) or/and intravenous injection of proUK (2.5 mg/kg, twice a week) began at 8 weeks after feeding with high fat diet and continued for 4 weeks. CP alone treatment markedly decreased plasma triglyceride, but did not ameliorate atherosclerosis plaque. No effect was observed for proUK alone on any endpoints tested. CP plus proUK induced a significantly reduction in the atherosclerotic lesions, along with decreased levels of total cholesterol, triglyceride in the plasma. CP plus proUK inhibited the elevated hepatic total cholesterol and triglyceride in high fat diet-fed LDLR^–/– mice, up-regulating the expressions of ATP-binding cassette gene 5 and 8, and adipose triglyceride lipase. In the aorta, CP plus proUK inhibited the expression of scavenger receptor A and CD36 in LDLR^–/– mice. In addition, we observed that systemic inflammation was inhibited, manifested downregulation of plasma macrophage inflammatory protein-1α and intercellular cell adhesion molecule-1.

Conclusion

CP plus proUK effectively attenuated atherosclerosis plaque in LDLR^–/– mice, which is associated with normalizing the lipid metabolism in the liver and aorta, reducing phagocytosis of receptor-mediated modified-LDL uptake and inhibiting systemic inflammation.

Yiqifumai injection and its main ingredients attenuate lipopolysaccharide-induced cerebrovascular hyperpermeability through a multi-pathway mode

OBJECTIVE

Yiqifumai injection is a compound Chinese medicine used to treat microcirculatory disturbance-related diseases clinically. Our previous study proved that Yiqifumai injection pretreatment inhibited lipopolysaccharide-induced venular albumin leakage in rat mesentery. This study aimed to investigate whether Yiqifumai injection attenuated cerebral microvascular hyperpermeability and corresponding contribution of its main ingredients.

METHODS

Rats were challenged by lipopolysaccharide infusion (5 mg/kg/h) for 90 minutes. Yiqifumai injection (160 mg/kg/h), Rb1 (5 mg/kg/h), Sch (2.5 mg/kg/h), and Rb1 (5 mg/kg/h) + Sch (2.5 mg/kg/h) were infused 30 minutes before (pretreatment) or after (post-treatment) lipopolysaccharide administration.

RESULTS

Both pretreatment and post-treatment with Yiqifumai injection attenuated cerebral venular albumin leakage during lipopolysaccharide infusion and cerebrovascular hyperpermeability at 72 hours after lipopolysaccharide infusion. Yiqifumai injection restrained the decreased junction protein expression, adenosine triphosphate content, and mitochondria complex I, II, IV, and V activities. Moreover, Yiqifumai injection inhibited toll-like receptor-4 expression, Src phosphorylation, and caveolin-1 expression. Its main ingredients Rb1 and Sch alone worked differently, with Rb1 being more effective for enhancing energy metabolism, while Sch attenuating toll-like receptor-4 expression and Src activation.

CONCLUSION

Yiqifumai injection exerts a protective and ameliorated effect on cerebral microvascular hyperpermeability, which is more effective than any of its ingredients, possibly due to the interaction of its main ingredients through a multi-pathway mode.

Ginsenoside Rb1 promotes intestinal epithelial wound healing through extracellular signal-regulated kinase and Rho signaling

BACKGROUND AND AIM

Daikenchuto, a traditional Japanese herbal medicine, has been reported to exhibit anti-inflammatory effects against intestinal inflammation. However, whether daikenchuto has a therapeutic effect against intestinal mucosal injuries remains unclear. Thus, the aim of this study was to determine the effect of daikenchuto on intestinal mucosal healing.

METHODS

Colitis was induced in male Wistar rats by using trinitrobenzenesulfonic acid. Daikenchuto (900 mg/kg/day) was administered for 7 days after the induction of colitis. Thereafter, intestinal mucosal injuries were evaluated by determining the colonic epithelial regeneration ratio ([area of epithelial regeneration/area of ulcer] × 100). Restoration of rat intestinal epithelial cells treated with daikenchuto and its constituent herbs (Zanthoxylum fruit, processed ginger, and ginseng) and ginsenoside Rb1, which is a ginseng ingredient, was evaluated using a wound-healing assay.

RESULTS

The colon epithelial regeneration ratio in the daikenchuto-treated rats was significantly higher than that in the control rats. Daikenchuto, ginseng, and ginsenoside Rb1 enhanced wound healing, and the ginsenoside Rb1-induced enhancement was inhibited by extracellular signal-regulated kinase and Rho inhibitors.

CONCLUSIONS

Daikenchuto and its constituent, ginsenoside Rb1, promoted wound healing. Because mucosal healing is one of the most important therapeutic targets in patients with inflammatory bowel disease, ginsenoside Rb1 may be a novel therapeutic agent against intestinal mucosal damage such as that occurring in intestinal bowel disease.

Pro-angiogenic Ginsenosides F1 and Rh1 Inhibit Vascular Leakage by Modulating NR4A1

Vascular endothelial growth factor (VEGF) plays a key role in angiogenesis, but VEGF-induced angiogenesis is often accompanied by a vascular permeability response. Ginsenosides are triterpenoid saponins from the well-known medicinal plant, ginseng, and have been considered a candidate for modulating angiogenesis. Here, we systemically investigated the effects of 10 different ginsenosides on human umbilical vein endothelial cells and newly identified that two PPT-type ginsenosides, F1 and Rh1 induce the migration and proliferation of endothelial cells. Interestingly, RNA transcriptome analysis showed that gene regulation induced by VEGF in endothelial cells is distinct from that of ginsenoside F1 and Rh1. In addition, F1 and Rh1 significantly inhibited vascular leakage both in vitro and in vivo, which are induced by vascular endothelial growth factor. Furthermore, comparative transcriptome analysis revealed that these effects of F1 and Rh1 on vascular leakage restoration are mainly caused by changes in VEGF-mediated TNFα signaling via NFκB, particularly by the suppression of expression and transcriptional activity of NR4A1 by F1 and Rh1, even in the presence of VEGF. These findings demonstrate that ginsenosides F1 and Rh1 can be a promising herbal remedy for vessel normalization in ischemic disease and cancer and that NR4A1 is the key target.

Ginsenoside Rg3 protects against iE-DAP-induced endothelial-to-mesenchymal transition by regulating the miR-139-5p-NF-κB axis

Background

Emerging evidence suggests that endothelial-to-mesenchymal transition (EndMT) in endothelial dysfunction due to persistent inflammation is a key component and emerging concept in the pathogenesis of vascular diseases. Ginsenoside Rg3 (Rg3), an active compound from red ginseng, has been known to be important for vascular homeostasis. However, the effect of Rg3 on inflammation-induced EndMT has never been reported. Here, we hypothesize that Rg3 might reverse the inflammation-induced EndMT and serve as a novel therapeutic strategy for vascular diseases.

Methods

EndMT was examined under an inflammatory condition mediated by the NOD1 agonist, γ-d-glutamyl-meso-diaminopimelic acid (iE-DAP), treatment in human umbilical vein endothelial cells. The expression of EndMT markers was determined by Western blot analysis, real-time polymerase chain reaction, and immunocytochemistry. The underlying mechanisms of Rg3-mediated EndMT regulation were investigated by modulating the microRNA expression.

Results

The NOD1 agonist, iE-DAP, led to a fibroblast-like morphology change with a decrease in the expression of endothelial markers and an increase in the expression of the mesenchymal marker, namely EndMT. On the other hand, Rg3 markedly attenuated the iE-DAP–induced EndMT and preserved the endothelial phenotype. Mechanically, miR-139 was downregulated in cells with iE-DAP–induced EndMT and partly reversed in response to Rg3 via the regulation of NF-κB signaling, suggesting that the Rg3–miR-139-5p-NF-κB axis is a key mediator in iE-DAP-induced EndMT.

Conclusion

These results suggest, for the first time, that Rg3 can be used to inhibit inflammation-induced EndMT and may be a novel therapeutic option against EndMT-associated vascular diseases.

Schisandrin Attenuates Lipopolysaccharide-Induced Lung Injury by Regulating TLR-4 and Akt/FoxO1 Signaling Pathways

Objective: Acute lung injury is a severe clinic condition with limited therapeutic approaches. This study evaluated whether schisandrin (Sch), an ingredient of Schisandra chinensis, has preventive effects on endothelium and epithelium injury induced by lipopolysaccharide (LPS) and the underlying mechanisms.

Methods: Male Wistar rats were continuously infused with LPS (5 mg/kg/h) via the left jugular vein for 90 min. In some rats, Sch (2.5 mg/kg/h) was administrated through the left jugular vein 30 min before LPS infusion. Leukocyte recruitment, levels of inflammatory cytokines, lung histology and edema, vascular and alveolar barrier disruption and related proteins were evaluated at indicated time point after LPS challenge.

Results: LPS infusion for 90 min resulted in an increased leukocyte adhesion to pulmonary venules and overproduction of cytokine and chemokine in both serum and lung homogenate. At 8 h after termination of LPS infusion, obvious Evans blue extravasation and lung edema were observed, along with an increased apoptosis, a decreased expression of tight junction and adherent junction proteins, and a reduction in von Willebrand factor (vWF) and keratin, all of which were attenuated by Sch treatment. Meanwhile, the LPS-elicited activation of TLR-4/NF-κB/MAPK and FoxO1 signaling was inhibited by Sch.

Conclusion: The present study revealed that pretreatment with Sch alleviated lung endothelium and epithelium injury after LPS stimulation, which is attributable to inhibition of cell injury and activation of cell regeneration via regulation of TLR-4/NF-κB/MAPK and Akt/FoxO1 signaling pathway.

Tongxinluo attenuates reperfusion injury in diabetic hearts by angiopoietin-like 4-mediated protection of endothelial barrier integrity via PPAR-α pathway

Objective

Endothelial barrier function in the onset and Tongxinluo (TXL) protection of myocardial ischemia/reperfusion (I/R) injury, and TXL can induce the secretion of Angiopoietin-like 4 (Angptl4) in human cardiac microvascular endothelial cells during hypoxia/reoxygenation. We intend to demonstrate whether TXL can attenuate myocardial I/R injury in diabetes, characterized with microvascular endothelial barrier disruption, by induction of Angptl4-mediated protection of endothelial barrier integrity.

Methods and results

I/R injury was created by coronary ligation in ZDF diabetic and non-diabetic control rats. The animals were anesthetized and randomized to sham operation or I/R injury with or without the exposure to insulin, rhAngptl4, TXL, Angptl4 siRNA, and the PPAR-α inhibitor MK886. Tongxinluo, insulin and rhAngptl4 have the similar protective effect on diabetic hearts against I/R injury. In I/R-injured diabetic hearts, TXL treatment remarkably reduced the infarct size, and protected endothelial barrier integrity demonstrated by decreased endothelial cells apoptosis, microvascular permeability, and myocardial hemorrhage, fortified tight junction, and upregulated expression of JAM-A, integrin-α5, and VE-cadherin, and these effects of TXL were as effective as insulin and rhAngptl4. However, Angptl4 knock-down with siRNA interference and inhibition of PPAR-α with MK886 partially diminished these beneficial effects of TXL and rhAngptl4. TXL induced the expression of Angptl4 in I/R-injured diabetic hearts, and was canceled by Angptl4 siRNA and MK886. TXL treatment increased myocardial PPAR-α activity, and was abolished by MK886 but not by Angptl4 siRNA.

Conclusions

TXL protects diabetic hearts against I/R injury by activating Angptl4-mediated restoration of endothelial barrier integrity via the PPAR-α pathway.

Resveratrol enhances vascular reactivity in mice following lipopolysaccharide challenge via the RhoA-ROCK-MLCP pathway

The aim of the present study was to identify whether sepsis-induced vascular hyporeactivity is associated with microcirculation disturbance and multiple organ injuries. The current study assessed the impact of resveratrol (Res) treatment on lipopolysaccharide (LPS) challenge mediated vascular hyporeactivity. Effects of Res treatment (30 mg/kg; i.m.) at 1 h following LPS stimulation (5 mg/kg; i.v.) on the survival time, mean arterial pressure (MAP), and maximal difference of MAP (ΔMAP) to norepinephrine (NE; 4.2 µg/kg) in mice were observed. The reactivity to gradient NE of isolated mesenteric arterioles and the association with the RhoA-RhoA kinase (ROCK)-myosin light chain phosphatase (MLCP) pathway were investigated by myography, and the signaling molecule protein levels were assessed using ELISA. Res treatment prolonged the survival time of mice subjected to LPS challenge, but did not prevent the LPS-induced hypotension and increase in ΔMAP. Res treatment and RhoA agonist U-46619 incubation prevented LPS-induced vascular hyporeactivity ex vivo, which were suppressed by incubation with ROCK inhibitor Y-27632. LPS-induced vascular hyporeactivity was not affected by the MLCP inhibitor okadaic acid incubation, but was further downregulated by the co-incubation of OA plus Y-27632. The inhibiting effect of Y-27632 on Res treatment was eradicated by incubation with U-46619. Furthermore, RhoA inhibitor C3 transferase did not significantly inhibit the enhancing role of Res treatment, which was further increased by U-46619 plus C3 transferase co-incubation. In addition, Res treatment eradicated the LPS-induced decreases in p-RhoA and p-Mypt1 levels and increases in MLCP levels. The results of the present study indicate that post-treatment of Res significantly ameliorates LPS-induced vascular hyporeactivity, which is associated with the activation of the RhoA-ROCK-MLCP pathway.

Mechanisms of endothelial dysfunction during aging: Predisposition to thrombosis

One of the risk factors for developing cardiovascular disease (CVD) is aging. In the elderly endothelial dysfunction occurs as altered endothelial ability to regulate hemostasis, vascular tone and cell permeability. In addition, there are changes in the expression and plasma levels of important endothelial components related to endothelial-mediated modulation in hemostasis. These include alterations in the metabolism of nitric oxide and prostanoides, endothelin-1, thrombomodulin and Von Willebrand factor. These alterations potentiate the pro-coagulant status developed with aging, highlighting the endothelial role in the development of thrombosis in aging.

RAGE Plays a Role in LPS-Induced NF-κB Activation and Endothelial Hyperpermeability

Endothelial functional dysregulation and barrier disruption contribute to the initiation and development of sepsis. The receptor for advanced glycation end products (RAGE) has been demonstrated to be involved in the pathogenesis of sepsis. The present study aimed to investigate the role of RAGE in lipopolysaccharide (LPS)-induced nuclear factor-κB (NF-κB) activation in endothelial cells and the consequent endothelial hyperpermeability. LPS-induced upregulation of RAGE protein expression in human umbilical vein endothelial cells (HUVECs) was detected by western blotting. Activation of NF-κB was revealed using western blotting and immunofluorescent staining. LPS-elicited endothelial hyperpermeability was explored by transendothelial electrical resistance (TER) assay and endothelial monolayer permeability assay. The blocking antibody specific to RAGE was used to confirm the role of RAGE in LPS-mediated NF-κB activation and endothelial barrier disruption. We found that LPS upregulated the protein expression of RAGE in a dose- and time-dependent manner in HUVECs. Moreover, LPS triggered a significant phosphorylation and degradation of IκBα, as well as NF-κB p65 nuclear translocation. Moreover, we observed a significant increase in endothelial permeability after LPS treatment. However, the RAGE blocking antibody attenuated LPS-evoked NF-κB activation and endothelial hyperpermeability. Our results suggest that RAGE plays an important role in LPS-induced NF-κB activation and endothelial barrier dysfunction.

Post-treatment with Ma-Huang-Tang ameliorates cold-warm-cycles induced rat lung injury

Frequent and drastic ambient temperature variation may cause respiratory diseases such as common cold and pneumonia, the mechanism for which is not fully understood, however, due to lack of appropriate animal models. Ma-Huang-Tang (MHT) is widely used in China for treatment of respiratory diseases. The present study aimed to investigate the effect of MHT on temperature alternation induced rat lung injury and explore underlying mechanisms. Male Sprague-Dawley rats were exposed to a cold environment for 1 h and then shifted to a warm environment for 30 min. This cold and warm alteration cycled 4 times. Rats were administrated with MHT (1.87 g/kg) by gavage 6 h after cold-warm-cycles. Cold-warm-cycles induced pulmonary microcirculatory disorders, lung edema and injury, decrease in the expression of tight junction proteins, increase in VE-cadherin activation, increase in the expression and activation of Caveolin-1, Src and NF-κB, and NADPH oxidase subunits p47^phox, p40^phox and p67^phox membrane translocation and inflammatory cytokines production. All alterations were significantly ameliorated by post-treatment with MHT. This study showed that rats subjected to cold-warm-cycles may be used as an animal model to investigate ambient temperature variation-induced lung injury, and suggested MHT as a potential strategy to combat lung injury induced by temperature variation.

Miconazole protects blood vessels from MMP9-dependent rupture and hemorrhage

Hemorrhagic stroke accounts for 10-15% of all strokes and is strongly associated with mortality and morbidity worldwide, but its prevention and therapeutic interventions remain a major challenge. Here, we report the identification of miconazole as a hemorrhagic suppressor by a small-molecule screen in zebrafish. We found that a hypomorphic mutant fn40a, one of several known β-pix mutant alleles in zebrafish, had the major symptoms of brain hemorrhage, vessel rupture and inflammation as those in hemorrhagic stroke patients. A small-molecule screen with mutant embryos identified the anti-fungal drug miconazole as a potent hemorrhagic suppressor. Miconazole inhibited both brain hemorrhages in zebrafish and mesenteric hemorrhages in rats by decreasing matrix metalloproteinase 9 (MMP9)-dependent vessel rupture. Mechanistically, miconazole downregulated the levels of pErk and Mmp9 to protect vascular integrity in fn40a mutants. Therefore, our findings demonstrate that miconazole protects blood vessels from hemorrhages by downregulating the pERK-MMP9 axis from zebrafish to mammals and shed light on the potential of phenotype-based screens in zebrafish for the discovery of new drug candidates and chemical probes for hemorrhagic stroke.

Summary: A phenotype-based chemical screen in zebrafish identifies miconazole as a novel hemorrhagic suppressor. Miconazole inhibits vessel rupture and hemorrhages by decreasing pErk and MMP9 in zebrafish and rats.

Catalpol restores LPS-elicited rat microcirculation disorder by regulation of a network of signaling involving inhibition of TLR-4 and SRC

LPS-induced microvascular hyperpermeability and hemorrhage play a key role in the development of sepsis, the attenuation of which might be an important strategy to prevent sepsis. However, the current clinical therapies have proven to be inefficient in improving the prognosis for patients with sepsis. Catalpol, an iridoid glycoside extracted from the roots of Rehmannia, has been reported to protect against LPS-induced acute lung injury through a Toll-like receptor-4 (TLR-4)-mediated NF-κB signaling pathway. However, it is still unknown whether catalpol can be an effective treatment to ameliorate the LPS-induced microvascular disorder. The present study aimed to investigate the impact of catalpol on LPS-induced mesenteric microvascular disorder and its underlying mechanism. Male Wistar rats were challenged by infusion of LPS (10 mg·kg^-1·h^-1) through the left femoral vein for 120 min. Post-treatment with catalpol (10 mg/kg) alleviated the LPS-induced microvascular hyperpermeability and hemorrhage; reduced mortality; ameliorated the alteration in the distribution of claudin-5 and the junctional adhesion molecule-1, as well as the degradation of collagen IV and laminin; and attenuated the increase of TLR-4 level, phosphorylations of Src tyrosine kinase, phosphatidyl inositol 3-kinase, focal adhesion kinase, and cathepsin B activation. In vitro study in human umbilical vein endothelial cells verified these results and further revealed that inhibition of TLR-4 and Src each simulated some, but not all, of the effects that catalpol exerted. Besides, surface plasmon resonance showed that catalpol could directly bind to TLR-4 and Src. These results demonstrated that catalpol was able to ameliorate the LPS-induced microvascular barrier damage and hemorrhage by targeting both TLR-4 and Src, thus attenuating the phosphorylation of Src kinase, phosphatidyl inositol 3-kinase, and focal adhesion kinase, as well as cathepsin B activation.

Ginsenoside Rb1 protects the intestinal mucosal barrier following peritoneal air exposure

Ginsenoside Rb1 (GRb1), which is one of the main ingredients derived from Panax ginseng, has been widely used to treat various gastrointestinal disorders. The present study aimed to determine whether GRb1 was able to prevent intestinal mucosal barrier damage in rats following peritoneal air exposure for 3 h. GRb1 (5, 10, and 20 mg/kg) was orally administrated via gavage four times prior to and following surgery. Blood and terminal ileum were sampled 24 h following surgery. Levels of serum D-lactate (D-LA) were detected using an enzyme-linked immunosorbent assay kit. Intestinal permeability was assessed by determining the intestinal clearance of fluorescein isothiocyanate-dextran (FD4). Activity of intestinal myeloperoxidase was measured to assess intestinal inflammation, and intestinal histopathology was assessed by light microscopy. The results showed that GRb1 reduced the level of serum D-LA, intestinal clearance of FD4, and the activity of intestinal myeloperoxidase. Intestinal edema and inflammation were also ameliorated by GRb1, and the Chiu's scores employed for assessing intestinal mucosal damage were also reduced in the GRb1-treated peritoneal air exposure group. In addition, GRb1 induced a significant difference at 10 and 20 mg/kg, indicating a dose-dependent effect. The results of the present study suggest that GRb1 may be able to protect the intestinal mucosal barrier against damage induced by peritoneal air exposure, which may be associated with its anti-inflammatory action.

Posthemorrhagic shock mesenteric lymph enhances monolayer permeability via F-actin and VE-cadherin

BACKGROUND

Vascular hyperpermeability plays a critical role in the development of refractory hypotension after severe hemorrhagic shock. Posthemorrhagic shock mesenteric lymph (PHSML) return has been shown to be involved in regulation of vascular hyperpermeability. The present study was conducted to investigate the effect of PHSML on permeability of endothelial cells in vitro.

MATERIALS AND METHODS

A hemorrhagic shock model (40 ± 2 mm Hg for 90 min, followed by fluid resuscitation) was used for collection of PHSML. Two separated PHSMLs were collected from period 0-3 h (early) and period 3-6 h (late) after resuscitation and diluted into concentration of 4% or 10%. The human umbilical vein endothelial cells (HUVECs) were then treated with these PHSMLs for 6 h. The monolayer cellular permeability to FITC-albumin was observed by using the costar transwell system. The multiple approaches including scanning electron microscope, fluorescent cytochemistry staining, and Western blotting were also used to assess the changes in cellular morphologic and the expressions of F-actin and VE-cadherin.

RESULTS

The treatments with either early or late PHSML resulted in morphologic injuries, increased cellular permeability, and decreased expression of F-actin in HUVECs. In contrast, only early PHSML, but not late PHSML, reduced the VE-cadherin expression.

CONCLUSIONS

These results indicate that the PHSML in vitro increases the cellular permeability of HUVECs through suppression of F-actin and VE-cadherin.

Molecular mechanisms in lipopolysaccharide-induced pulmonary endothelial barrier dysfunction

The confluent pulmonary endothelium plays an important role as a semi-permeable barrier between the vascular space of blood vessels and the underlying tissues, and it contributes to the maintenance of circulatory fluid homeostasis. Pulmonary endothelial barrier dysfunction is a pivotal early step in the development of a variety of high mortality diseases, such as acute lung injury (ALI). Endothelium barrier dysfunction in response to inflammatory or infectious mediators, including lipopolysaccharide (LPS), is accompanied by invertible cell deformation and interendothelial gap formation. However, specific pharmacological therapies aiming at ameliorating pulmonary endothelial barrier function in patients are still lacking. A full understanding of the fundamental mechanisms that are involved in the regulation of pulmonary endothelial permeability is essential for the development of barrier protective therapeutic strategies. Therefore, this review summarizes several important molecular mechanisms involved in LPS-induced changes in pulmonary endothelial barrier function. As for barrier-disruption, the activation of myosin light chain kinase (MLCK), RhoA and tyrosine kinases; increase of calcium influx; and apoptosis of the endothelium lead to an elevation of lung endothelial permeability. Additionally, the activation of Rac1, Cdc42, protease activated receptor 1 (PAR1) and adenosine receptors (ARs), as well as the increase of cyclic AMP and sphingosine-1-phosphate (S1P) content, protect against LPS-induced lung endothelial barrier dysfunction. Furthermore, current regulatory factors and strategies against the development of LPS-induced lung endothelial hyper-permeability are discussed.

Salvianolic Acid B Ameliorates Lipopolysaccharide-Induced Albumin Leakage from Rat Mesenteric Venules through Src-Regulated Transcelluar Pathway and Paracellular Pathway

Lipopolysaccharide (LPS) causes microvascular barrier disruption, leading to albumin leakage from microvessels resulting in a range of disastrous sequels. Salvianolic acid B (SalB) is a major water-soluble component derived from Salvia miltiorrhiza. Previous studies showed its potential to attenuate microvascular barrier dysfunction, but the underlying mechanism is not fully understood. The present study was intended to investigate the impact of SalB on endothelial cell barrier in vivo in rat mesenteric venules as well as in vitro in human umbilical vein endothelial cells (HUVECs), aiming at disclosing the mechanism thereof, particularly the role of Src in its action. Male Wistar rats were challenged by infusion of LPS (2 mg/kg/h) through left femoral vein for 90 min. SalB (5 mg/kg/h) was administrated either simultaneously with LPS or 30 min after LPS infusion through the left jugular vein. Vesicles in venular walls were observed by electron microscopy. HUVECs were incubated with LPS with or without SalB. The expression of Zonula occluden-1 (ZO-1), VE-cadherin, caveolin-1 and Src in HUVECs was assessed by Western blot and confocal microscopy, binding of SalB to Src was measured using Surface Plasmon Resonance and BioLayer Interferometry. Treatment with SalB inhibited albumin leakage from rat mesenteric venules and inhibited the increase of vesicle number in venular endothelial cells induced by LPS. In addition, SalB inhibited the degradation of ZO-1, the phosphorylation and redistribution of VE-cadherin, the expression and phosphorylation of caveolin-1, and phosphoirylation of Src in HUVECs exposed to LPS. Furthermore, SalB was found able to bind to Src. This study demonstrates that protection of SalB against microvascular barrier disruption is a process involving both para- and trans-endothelial cell pathway, and highly suggests Src as the key enzyme for SalB to work.

Interaction between mesenchymal stem cells and endothelial cells restores endothelial permeability via paracrine hepatocyte growth factor in vitro

Introduction

Mesenchymal stem cells (MSCs) have potent stabilising effects on vascular endothelium injury, inhibiting endothelial permeability in lung injury via paracrine hepatocyte growth factor (HGF). Recently, it has been indicated that MSCs secrete more factors by MSC-endothelial cell (MSC-EC) interactions. We hypothesised that MSC-EC interactions restore endothelial permeability induced by lipopolysaccharide (LPS) via paracrine HGF.

Methods

We investigated the endothelial permeability induced by LPS under two co-culture conditions. Human pulmonary microvascular endothelial cells (HPMECs) were added into the upper chambers of cell-culture inserts, while two different co-culture conditions were used in the lower side of the transwells, as follows: (1) MSC-EC interaction group: MSCs and HPMECs contact co-culture; (2) MSC group: MSCs only. The endothelial paracellular and transcellular permeabilities in the upper side of transwells were detected. Then the concentration of HGF was measured in the culture medium by using an enzyme-linked immunosorbent assay kit, followed by neutralisation of HGF with anti-HGF antibody in the co-culture medium. In addition, adherens junction and cytoskeleton protein expressions were measured by Western blot and immunofluorescence. HPMEC proliferation was analysed by bromodeoxyuridine incorporation assay.

Results

The paracellular permeability significantly increased after LPS stimulation in a dose-dependent and time-dependent manner. Meanwhile, MSC-EC interaction more significantly decreased endothelial paracellular and transcellular permeability induced by LPS. Moreover, HGF levels in the MSC-EC interaction group were much higher than those of the MSC group. However, neutralising HGF with anti-HGF antibody inhibited the role of MSC-EC interaction in improving endothelial permeability. Compared with the MSC group, MSC-EC interaction increased vascular endothelial (VE)-cadherin and occludin protein expression, reduced caveolin-1 protein expression in HPMECs, and restored remodelling of F-actin and junctional localisation of VE-cadherin. Furthermore, the proliferation ratio in the MSC-EC interaction group was higher than that of the MSC group. However, the effects of MSCs were significantly blocked by anti-HGF antibody.

Conclusions

These data suggested that MSC-EC interaction decreased endothelial permeability induced by LPS, which was attributed mainly to HGF secreted by MSCs. The main mechanisms by which HGF restored the integrity of endothelial monolayers were remodelling of endothelial intercellular junctions, decreasing caveolin-1 protein expression, and inducing proliferation in HPMECs.

Electronic supplementary material

The online version of this article (doi:10.1186/s13287-015-0025-1) contains supplementary material, which is available to authorized users.