Neferine inhibits the upregulation of CCL5 and CCR5 in vascular endothelial cells during chronic high glucose treatment

CCR5 antagonist treatment inhibits vascular injury by regulating NADPH oxidase 1

BACKGROUND

Chemokine (C- Cmotif) ligand 5 (CCL5) and its receptor C-C motif chemokine receptor 5 (CCR5), have been broadly studied in conjunction with infectious pathogens, however, their involvement in cardiovascular disease is not completely understood. NADPH oxidases (Noxs) are the major source of reactive oxygen species (ROS) in the vasculature. Whether the activation of Noxs is CCL5/CCR5 sensitive and whether such interaction initiates vascular injury is unknown. We investigated whether CCL5/CCR5 leads to vascular damage by activating Noxs.

MATERIAL AND METHODS

We used rat aortic smooth muscle cells (RASMC) to investigate the molecular mechanisms by which CCL5 leads to vascular damage and carotid ligation (CL) to analyze the effects of blocking CCR5 on vascular injury.

RESULTS

CCL5 induced Nox1 expression in concentration and time-dependent manners, with no changes in Nox2 or Nox4. Maraviroc pre-treatment (CCR5 antagonist, 40uM) blunted CCL5-induced Nox1 expression. Furthermore, CCL5 incubation led to ROS production and activation of Erk1/2 and NFkB, followed by increased vascular cell migration, proliferation, and inflammatory markers. Notably, Nox1 inhibition (GKT771, 10uM) blocked CCL5-dependent effects. In vivo, CL induced pathological vascular remodeling and inflammatory genes and increased Nox1 and CCR5 expression. Maraviroc treatment (25 mg/Kg/day) reduced pathological vascular growth and Nox1 expression.

CONCLUSIONS

Our findings suggest that CCL5 activates Nox1 in the vasculature, leading to vascular injury likely via NFkB and Erk1/2. Herein, we place CCR5 antagonists and/or Nox1 inhibitors might be preeminent antiproliferative compounds to reduce the cardiovascular risk associated with medical procedures (e.g. angioplasty) and vascular diseases associated with vascular hyperproliferation.

CCL4 induces inflammatory signalling and barrier disruption in the neurovascular endothelium

Background

During neuroinflammation many chemokines alter the function of the blood-brain barrier (BBB) that regulates the entry of macromolecules and immune cells into the brain. As the milieu of the brain is altered, biochemical and structural changes contribute to the pathogenesis of neuroinflammation and may impact on neurogenesis. The chemokine CCL4, previously known as MIP-1β, is upregulated in a wide variety of central nervous system disorders, including multiple sclerosis, where it is thought to play a key role in the neuroinflammatory process. However, the effect of CCL4 on BBB endothelial cells (ECs) is unknown.

Materials and methods

Expression and distribution of CCR5, phosphorylated p38, F-actin, zonula occludens-1 (ZO-1) and vascular endothelial cadherin (VE-cadherin) were analysed in the human BBB EC line hCMEC/D3 by Western blot and/or immunofluorescence in the presence and absence of CCL4. Barrier modulation in response to CCL4 using hCMEC/D3 monolayers was assessed by measuring molecular flux of 70 ​kDa RITC-dextran and transendothelial lymphocyte migration. Permeability changes in response to CCL4 in vivo were measured by an occlusion technique in pial microvessels of Wistar rats and by fluorescein angiography in mouse retinae.

Results

CCR5, the receptor for CCL4, was expressed in hCMEC/D3 cells. CCL4 stimulation led to phosphorylation of p38 and the formation of actin stress fibres, both indicative of intracellular chemokine signalling. The distribution of junctional proteins was also altered in response to CCL4: junctional ZO-1 was reduced by circa 60% within 60 ​min. In addition, surface VE-cadherin was redistributed through internalisation. Consistent with these changes, CCL4 induced hyperpermeability in vitro and in vivo and increased transmigration of lymphocytes across monolayers of hCMEC/D3 cells.

Conclusion

These results show that CCL4 can modify BBB function and may contribute to disease pathogenesis.

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The chemokine CCL4 induced phosphorylation of P38 in an in vitro model of the blood-brain barrier (BBB).

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CCL4 treatment resulted in reduction of plasma membrane VE-cadherin and junctional ZO-1.

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CCL4 induced neurovascular barrier breakdown in vitro and in vivo.

Endothelial Dysfunction, Inflammation, and Oxidative Stress in COVID-19-Mechanisms and Therapeutic Targets

The outbreak of the COVID-19 pandemic represents an ongoing healthcare emergency responsible for more than 3.4 million deaths worldwide. COVID-19 is the disease caused by SARS-CoV-2, a virus that targets not only the lungs but also the cardiovascular system. COVID-19 can manifest with a wide range of clinical manifestations, from mild symptoms to severe forms of the disease, characterized by respiratory failure due to severe alveolar damage. Several studies investigated the underlying mechanisms of the severe lung damage associated with SARS-CoV-2 infection and revealed that the respiratory failure associated with COVID-19 is the consequence not only of acute respiratory distress syndrome but also of macro- and microvascular involvement. New observations show that COVID-19 is an endothelial disease, and the consequent endotheliopathy is responsible for inflammation, cytokine storm, oxidative stress, and coagulopathy. In this review, we show the central role of endothelial dysfunction, inflammation, and oxidative stress in the COVID-19 pathogenesis and present the therapeutic targets deriving from this endotheliopathy.

Neferine suppresses vascular endothelial inflammation by inhibiting the NF-κB signaling pathway

The vascular endothelium, as the interface between the blood and the surrounding tissues, plays a pivotal role in inflammation. Neferine, which was isolated from Lotus Plumule, has many biological roles, such as antifibrotic, antioxidative, anti-inflammatory, and antineoplastic activities. We demonstrated the role of neferine in the inhibition of pro-adhesion and pro-inflammatory responses of endothelial cells in vitro. We found that neferine could significantly inhibit the adhesion of Tohoku Hospital Pediatrics-1 (THP-1) cells to primary human umbilical vein endothelial cells (HUVECs). At the molecular level, neferine could significantly alleviate the interleukin 1β (IL-1β)-induced mRNA and protein expression of intercellular adhesion molecule 1 (ICAM1) and vascular cell adhesion molecule 1 (VCAM1). Our data showed that neferine suppressed nuclear factor-κB (NF-κB) nuclear translocation and inhibited the NF-κB-p65-induced transcriptional activity of ICAM1 and VCAM1. Therefore, we concluded that neferine suppressed the inflammatory response in endothelial cells in vitro, which could be mainly due to inhibition of NF-κB signaling activation. Moreover, we found that neferine alleviated LPS-induced acute inflammation injury in vivo. Thus, neferine may serve as an effective regulator during the pathogenesis of vascular inflammatory diseases.

Neferine alleviates P2X3 receptor in rat dorsal root ganglia mediated neuropathic pain

Chronic neuropathic pain is caused by tissue damage or nervous system inflammation and is characterized by sensitivity to painful stimuli. P2X3 receptors play an important role in facilitating pain transmission. Neferine is a bisbenzylisoquinline alkaloid isolated from seed embryos of lotus, which has anti-inflammatory and anti-oxidation pharmacological functions. The present research investigated whether neferine relieves neuropathic pain related to the P2X3 receptor in rat dorsal root ganglia (DRGs). Chronic contraction injury (CCI) in rats was used as a model for neuropathic pain. The results indicated that the expression of P2X3 receptor was significantly increased in the DRGs of CCI rats and that mechanical allodynia and thermal hyperalgesia were also enhanced in CCI rats. Neferine markedly lowered the upregulated P2X3 receptor and interleukin-1beta, inhibited the phosphorylation and activation of ERK1/2 in the DRGs of CCI rats, and relieved neuropathic pain. Therefore, neferine alleviates neuropathic pain by downregulating the expression of P2X3 receptor.

Myosin light chain kinase inhibitor ML7 improves vascular endothelial dysfunction and permeability via the mitogen-activated protein kinase pathway in a rabbit model of atherosclerosis

Endothelial dysfunction (ED) and hyperpermeability are considered as the initiating steps in early atherosclerosis. Phosphorylation of myosin light chain (MLC) is key to cause vascular hyperpermeability via endothelial cell contraction. However, it is unclear whether MLC phosphorylation can also regulate the balance between contraction and relaxation of endothelial cells, thereby affecting endothelium-dependent diastolic function and leading to ED. The present study investigated relationships between ED and MLC phosphorylation and underlying mechanisms. Twenty-four male New Zealand white rabbits were randomly divided into three groups: control, AS, and ML7 (MLCK inhibitor) groups, and fed with normal diet, high-fat diet (HFD), and HFD plus oral ML7 (1 mg/kg daily) respectively. HFD-fed rabbits showed typical atheromatous lesions and endothelial hyperpermeability, and these lesions could be partly reversed following ML7 therapy. Western blotting revealed significant increased expression of myosin light chain kinase (MLCK) and phosphorylation of MLC, JNK, and ERK in the arterial wall of rabbits in the AS group compared with those of the control group (p < 0.05), whereas the ML7 group showed markedly decreased levels of these proteins compared with the AS group (p <  0.05). The endothelium-dependent relaxation rate was significantly reduced both in vitro and in vivo in AS group, and was improved using ML7 therapy. Taken together, these results indicate that MLCK expression and subsequent MLC phosphorylation increase vascular endothelial permeability and endothelium-dependent diastolic dysfunction by promoting endothelial cell contraction, which may be initiated by the activation of the MAP/ERK (MEK) and MAP/JNK (MEK) pathways.

Chemokine Receptor 5, a Double-Edged Sword in Metabolic Syndrome and Cardiovascular Disease

The key characteristic of cardiovascular disease (CVD) is endothelial dysfunction, which is likely the consequence of inflammation. It is well demonstrated that chemokines and their receptors play a crucial role in regulating inflammatory responses, and recently, much attention has been paid to chemokine receptor 5 (CCR5) and its ligands. For example, CCR5 aggravates the inflammatory response in adipose tissue by regulating macrophage recruitment and M1/M2 phenotype switch, thus causing insulin resistance and obesity. Inhibition of CCR5 expression reduces the aggregation of pro-atherogenic cytokines to the site of arterial injury. However, targeting CCR5 is not always effective, and emerging evidence has shown that CCR5 facilitates progenitor cell recruitment and promotes vascular endothelial cell repair. In this paper, we provide recent insights into the role of CCR5 and its ligands in metabolic syndrome as related to cardiovascular disease and the opportunities and roadblocks in targeting CCR5 and its ligands.

Neferine inhibits LPS-ATP-induced endothelial cell pyroptosis via regulation of ROS/NLRP3/Caspase-1 signaling pathway

BACKGROUND

Oxidative stress-induced endothelial dysfunction and pyroptosis play an important role during chronic kidney disease (CKD) progression. Neferine, which is an alkaloid ingredient from the lotus seed embryo, has many biological actions such as anti-inflammatory, anticancer and antioxidant. However, the role of neferine in endothelial cell pyroptosis and the involved mechanism remain obscure. The aim is to probe the protective effects of neferine on cell pyroptosis and the involved underlying mechanism.

METHODS

After the HUVECs were primed with neferine treatment for 2 h prior to LPS and ATP exposure for 24 h, the cell proliferation was determined by BrdU; the cell LDH release was detected by LDH kits; the levels of intracellular ROS, MDA and SOD were tested by detection kits; Caspase-1 activity kit was used to determine caspase-1 activity; the contents of NLRP3, ASC, caspase-1, IL-1β, IL-18 and GSDMD were tested by RT-PCR and western blot.

RESULTS

We found that neferine could inhibit LPS-ATP-induced oxidative stress and the activation of NLRP3 inflammasome signaling, and increased the endothelial cell viability and SOD production. siRNA which mediated the knockdown of NLRP3 promoted the neferine-induced inhibition effects of cell pyroptosis. Furthermore, these neferine-induced effects were reversed by the over-expression of NLRP3.

CONCLUSIONS

Our findings indicated neferine may reduce ROS by anti-oxidation and inhibit LPS-ATP-induced endothelial cell pyroptosis via blocking ROS/NLRP3/Caspase-1 signaling pathway, which provides the evidence for therapeutic effect in CKD.

Neferine, a Bisbenzylisoquinoline Alkaloid, Ameliorates Dextran Sulfate Sodium-Induced Ulcerative Colitis

Both the incidence and prevalence of ulcerative colitis (UC) are increasing throughout the world. Neferine, a natural alkaloid, demonstrated a variety of biological activities. In this study, the anti-inflammatory effect of neferine was investigated. Raw264.7 cells were stimulated with lipopolysaccharide (LPS) or LPS plus Z-VAD-fmk (Z-VAD). The inhibitory effect of neferine on secretion of nitrite, cytokines tumor necrosis factor alpha (TNF-[Formula: see text]) and interleukin 6 (IL-6), expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) was determined. The protective effect of neferine was investigated in dextran sulfate sodium (DSS)-induced UC mouse model. Neferine significantly inhibited LPS and LPS plus Z-VAD induced secretion of nitrite, cytokines, and expression of iNOS and COX-2. Oral administration of neferine (10[Formula: see text]mg/kg and 25[Formula: see text]mg/kg) significantly reduced DSS-induced mouse weight loss, decreased disease activity index (DAI) scores, improved colon pathological changes, and decreased plasma cytokines. In addition, neferine significantly inhibited the protein expression of iNOS, COX-2, receptor-interacting protein 1 (RIP1), RIP3, mixed lineage kinase domain-like protein (MLKL), and increased the protein expression of caspase-8 in colon tissues. These data suggest that neferine was a potent anti-inflammatory agent against LPS and DSS induced inflammation both in vitro and in vivo.

Evodiamine Attenuates P2X7-Mediated Inflammatory Injury of Human Umbilical Vein Endothelial Cells Exposed to High Free Fatty Acids

Insulin resistance and type 2 diabetes mellitus (T2DM) are highly prevalent around the world. Elevated concentrations of free fatty acids (FFAs) are closely related to insulin resistance and T2DM. P2X₇ receptor is an ion channel gated by ATP, which is implicated in various scenarios including immune response, pain, and inflammation. In this study, we have explored whether P2X₇ receptor is involved in pathological changes in human umbilical vein endothelial cells (HUVECs) induced by high FFA treatment, and the potential beneficial effects of evodiamine. Evodiamine could effectively suppress the enhanced expression of P2X₇ receptor caused by high FFAs at both mRNA and protein levels. In addition, high FFA-induced cytotoxicity, the upregulated release of ATP, and production of reactive oxygen species (ROS) could be ameliorated by evodiamine in HUVECs. Evodiamine could also reverse the decreased NO formation and the increased adhesive events of immune cells at high FFAs. Moreover, evodiamine inhibited P2X₇-dependent TNF-α expression and ERK 1/2 phosphorylation due to high FFAs. All these results indicated that evodiamine could correct the upregulated expression of P2X₇ receptor induced under high FFA condition in HUVECs, and consequently suppressed oxidative stress and inflammatory responses.

Pharmacological benefits of neferine - A comprehensive review

This article recapitulates the existing in vitro and in vivo studies focusing on the effects of neferine-an alkaloid derivative of lotus plant, in various disease models and its effects on key signaling molecules. The review also compiles a large number of research studies that demonstrate methods for isolation and extraction, biosynthetic pathway, pharmacological activity and mode of action of neferine and their underlying mechanisms at cellular level. Neferine is a unique bis-benzylisoquinoline alkaloid that possesses a number of therapeutic effects such as anti-cancer, anti-diabetic, anti-aging, anti-microbial, anti-thrombotic, anti-arrhythmic, anti-inflammatory and even anti-HIV. It also enhances the anti-cancer properties of other anti-cancer drugs like cisplatin, adriamycin, taxol, etc. It is also reported to reverse chemo-resistance and enhance sensitivity of the cancer cells towards anti-cancer drugs. The underlying mechanisms for its activities mainly include apoptosis, autophagy and G1 arrest. Neferine protects them against the effect of drugs like cisplatin. The therapeutic properties of neferine is widely diverse, while it shows toxicity to cancer it also shows cyto-protective effects against cardio-vascular diseases, pulmonary disease, and is also effective against Alzheimer's disease and elicits anti-oxidative effect in many cellular systems. This article thus is the first ever attempt to review the therapeutic activities of neferine established in in vitro and in vivo models and to compile all the fragmented data available on the omnipotent activities of neferine.

Emerging role of chemokine CC motif ligand 4 related mechanisms in diabetes mellitus and cardiovascular disease: friends or foes?

Chemokines are critical components in pathology. The roles of chemokine CC motif ligand 4 (CCL4) and its receptor are associated with diabetes mellitus (DM) and atherosclerosis cardiovascular diseases. However, due to the complexity of these diseases, the specific effects of CCL4 remain unclear, although recent reports have suggested that multiple pathways are related to CCL4. In this review, we provide an overview of the role and potential mechanisms of CCL4 and one of its major receptors, fifth CC chemokine receptor (CCR5), in DM and cardiovascular diseases. CCL4-related mechanisms, including CCL4 and CCR5, might provide potential therapeutic targets in DM and/or atherosclerosis cardiovascular diseases.

Beneficial effects of evodiamine on P2X(4)-mediated inflammatory injury of human umbilical vein endothelial cells due to high glucose

Evodiamine has been reported to exhibit anti-inflammatory and anti-nociceptive effects, but the underlying mechanisms remain to be defined. P2X4 receptor (P2X4R) is a subtype of ATP receptors and plays important roles in pain, inflammatory and immune responses. We aimed to investigate whether evodiamine has beneficial effects on endothelial inflammatory injury mediated by chronic high glucose condition. We found that culturing human umbilical vein endothelial cells (HUVECs) with high glucose significantly increased the expression of P2X4 receptor in HUVECs, cytosolic Ca(2+) concentrations and intracellular reactive oxygen species (ROS) while decreasing nitric oxide (NO); these effects could be reversed by evodiamine. High glucose also significantly increased the expression of the pro-inflammatory activators (NF-κB) and TNFR-ɑ, which was accompanied by the elevation of P2X4R levels. Evodiamine was able to down-regulate the elevated NF-κB, TNFR-ɑ, P2X4R and ROS, and up-regulate the decreased NO. Thus the evodiamine may exert the anti-inflammation activity on high-glucose challenge HUVEC via suppressing the P2X4R signaling pathway, exhibiting beneficial ability to protect HUVECs from glucotoxicity.

PRDX6 promotes tumor development via the JAK2/STAT3 pathway in a urethane-induced lung tumor model

Peroxiredoxin 6 (PRDX6) is a bifunctional protein with both glutathione peroxidase (GPx) and iPLA2 activities. Even though several pathophysiological functions have been studied, the definitive role of PRDX6 in tumor growth is not clear. Here, we compared carcinogen-induced tumor growth in PRDX6-transgenic (Tg) mice and non-Tg mice to evaluate the roles of PRDX6 in lung tumor development. Urethane (1g/kg)-induced tumor incidence in PRDX6-Tg mice was significantly higher compared to non-Tg mice. In the tumors of PRDX6-Tg mice, the activation of JAK2/STAT3 and STAT3 DNA binding were also increased, accompanied by increased GPx and iPLA2 activities. PRDX6 was colocalized with JAK2 in tumor tissues and lung cancer cells and also showed physical interaction with JAK2. We found that increasing levels of PRDX6 increase the activation of the JAK2/STAT3 pathway. Furthermore, PRDX6-Tg mice showed altered cytokine levels in the tumors, especially leading to increased CCL5 levels. We validated that the activation of JAK2 was also decreased in lung tumors of CCR5(-/-) mice, and CCL5 increased the JAK2/STAT3 pathway in the lung cancer cells. Thus, our findings suggest that PRDX6 promotes lung tumor development via its mediated and CCL5-associated activation of the JAK2/STAT3 pathway.

Protection of vascular endothelial cells from high glucose-induced cytotoxicity by emodin

Induction of endothelial cytotoxicity by hyperglycemia in diabetes has been widely accepted. Emodin is a natural anthraquinone in rhubarb used for treatment of diabetes, but its mechanism of action is not fully understood. This study aimed to examine the potential beneficial effects of emodin on endothelial cytotoxicity caused by high glucose milieu. Culture of human umbilical vein endothelial cells (HUVECs) with high concentrations of glucose resulted in damage to the cells, leading to decreased formazan products by 14-27%, reduced DNA contents by 12-19%, and increased hypodiploid apoptosis by 40-109%. These adverse effects of high glucose could be prevented to a large extent by co-culture with 3 μM of emodin which per se did not affect HUVECs viability. In addition, CCL5 expression of HUVECs cultured in high glucose medium was significantly elevated at both mRNA and protein levels, an effect abolished after treatment with emodin. Moreover, the enhanced adhesion of monocytes to HUVECs (2.1-2.2 fold over control) and elevated chemotaxis activities (2.3-2.4 fold over control) in HUVECs cultured in high glucose medium were completely reversed by emodin. Emodin also suppressed activation of p38 MAPK and ERK1/2 due to high glucose. Our data demonstrated that endothelial cytotoxicity occurred clearly when HUVECs were exposed to high glucose milieu and emodin was able to alleviate the impairments. The protective effects of emodin might be related to the inhibition of CCL5 expression and subsequent cell stress/inflammatory events possibly mediated by activation of MAPK signaling pathways.