Alisol B 23-Acetate Inhibits IgE/Ag-Mediated Mast Cell Activation and Allergic Reaction

Moniezia benedeni infection increases IgE+ cells in sheep (Ovis aries) small intestine

The concentration of immunoglobulin (Ig) E is the lowest among serum Igs, but it can induces type I hypersensitivity and plays an important role in anti-parasitic infection. The present study aimed to explore the residence characteristics of IgE+ cells in the sheep small intestine and the impact of Moniezia benedeni infection on them. The recombinant plasmids pET-28a-IgE were constructed and induced and expressed in Escherichia coli. BL21 (DE3). The rabbit anti-sheep IgE polyclonal antibody was prepared using the obtained recombinant protein as antigen. Finally, the levels of IgE+ cells in the small intestine of healthy (Control group) and naturally M. benedeni-infected (Infected group) sheep were detected analyzed. The results showed that the rabbit anti-sheep IgE polyclonal antibody with good immunogenicity (titer = 1: 128000) could specifically bind to the heavy chain of natural sheep IgE. In the Control group, the IgE+ cells were mainly distributed in lamina propria of the small intestine, and the densities were significantly decreased from duodenum to ileum (P<0.05), with respective values of (4.28 cells / 104 μm2, 1.80 cells / 104 μm2, and 1.44 cells / 104 μm2 in duodenum, jejunum, and ileum. In the Infected group, IgE+ cells density were 6.26 cells / 104 μm2, 3.01 cells / 104 μm2, and 2.09 cells / 104 μm2 in duodenum, jejunum and ileum respectively, which were significantly higher in all segments compared to the Control group (P<0.05), increasing by 46.26%, 67.22% and 45.14%, respectively. In addition, compared with the Control group, the IgE protein levels were significantly increased in all intestinal segments of the Infected group (P<0.01), however, there was no significant differences among the different intestinal segments within the same group (P>0.05). The results demonstrated that M. benedeni infection could significantly increase the content of IgE and the distribution density of its secreting cells in sheep small intestine. The intestinal mucosal immune system of sheep presented obvious specificity against M. benedeni infection. This lays a good foundation for further exploring molecular mechanisms of the intestinal mucosal immune system monitoring and responding to M. benedeni infection.

Alisol B 23-Acetate Ameliorates Ovalbumin-Induced Allergic Asthma during Sensitization and Challenge Periods

Rhizome of Alisma orientale has been used as a traditional medicine for treating kidney diseases in East Asian countries. Its inhibitory effects on hypersensitivity responses have been reported for methanol extracts, with alisol B 23-acetate (AB23Ac) being the most active constituent among six terpenes in inhibiting the direct passive Arthus reaction. However, whether AB23Ac has efficacy against allergic asthma has not been tested to date. The in vivo efficacy of AB23Ac in an ovalbumin (OVA)-induced allergic asthma mouse model was evaluated by administrating AB23Ac before OVA sensitization or OVA challenge in BALB/c mice. AB23Ac suppressed antigen-induced degranulation of RBL-2H3 mast cells in a concentration-dependent manner. The administration of AB23Ac both before OVA sensitization and OVA challenge greatly lowered pulmonary resistance and the increase in immune cell counts and inflammatory responses around the peribronchial and perivascular regions. In addition, the inflammatory cytokine levels of Th1/Th2/Th17 cells in the bronchoalveolar lavage fluid decreased in the AB23Ac-treated groups. AB23Ac reduced the number of PAS-stained cells in the lungs. Furthermore, a computer modeling study indicated that AB23Ac can bind tightly to spleen tyrosine kinase (Syk). These results suggest that AB23Ac may ameliorate allergic asthma by suppressing immune responses in dendritic cells during sensitization and in mast cells during challenge periods.

Exploring the mechanism of Alisma orientale for the treatment of pregnancy induced hypertension and potential hepato-nephrotoxicity by using network pharmacology, network toxicology, molecular docking and molecular dynamics simulation

Background: Pregnancy-induced Hypertension (PIH) is a disease that causes serious maternal and fetal morbidity and mortality. Alisma Orientale (AO) has a long history of use as traditional Chinese medicine therapy for PIH. This study explores its potential mechanism and biosafety based on network pharmacology, network toxicology, molecular docking and molecular dynamics simulation. Methods: Compounds of AO were screened in TCMSP, TCM-ID, TCM@Taiwan, BATMAN, TOXNET and CTD database; PharmMapper and SwissTargetPrediction, GeneCards, DisGeNET and OMIM databases were used to predict the targets of AO anti-PIH. The protein-protein interaction analysis and the KEGG/GO enrichment analysis were applied by STRING and Metascape databases, respectively. Then, we constructed the "herb-compound-target-pathway-disease" map in Cytoscape software to show the core regulatory network. Finally, molecular docking and molecular dynamics simulation were applied to analyze binding affinity and reliability. The same procedure was conducted for network toxicology to illustrate the mechanisms of AO hepatotoxicity and nephrotoxicity. Results: 29 compounds with 78 potential targets associated with the therapeutic effect of AO on PIH, 10 compounds with 117 and 111 targets associated with AO induced hepatotoxicity and nephrotoxicity were obtained, respectively. The PPI network analysis showed that core therapeutic targets were IGF, MAPK1, AKT1 and EGFR, while PPARG and TNF were toxicity-related targets. Besides, GO/KEGG enrichment analysis showed that AO might modulate the PI3K-AKT and MAPK pathways in treating PIH and mainly interfere with the lipid and atherosclerosis pathways to induce liver and kidney injury. The "herb-compound-target-pathway-disease" network showed that triterpenoids were the main therapeutic compounds, such as Alisol B 23-Acetate and Alisol C, while emodin was the main toxic compounds. The results of molecular docking and molecular dynamics simulation also showed good binding affinity between core compounds and targets. Conclusion: This research illustrated the mechanism underlying the therapeutic effects of AO against PIH and AO induced hepato-nephrotoxicity. However, further experimental verification is warranted for optimal use of AO during clinical practice.

The Mechanism of Alisol B23 Acetate Inhibiting Lung Cancer: Targeted Regulation of CD11b/CD18 to Influence Macrophage Polarization

Background

Tumor microenvironment has attracted more and more attention in oncology. Alisol B23 acetate (AB23A) inhibits the proliferation of tumor cells including non-small cell lung cancer (NSCLC) cells. However, whether AB23A plays a role in the tumor microenvironment of NSCLC still remains obscure.

Methods

After THP-1 cells were polarized to M0 type by PMA, M0 macrophages were differentiated into M1 by LPS and IFNγ, and were differentiated into M2 by IL-4 and IL-13. The differentiation of THP-1 cells was detected by flow cytometry. After AB23A was given to macrophage RT-qPCR and ELISA detected the expressions of IL-6, IL-1β, IL-10 and TGF-β. Western blot and RT-qPCR detected the expressions of CD11b and CD18 at both mRNA and protein levels. Lung cancer cell A549 cells were induced by above related macrophage culture medium. Cell proliferation was detected by CCK-8. Tunel, wound healing and Transwell detected the apoptotic, migration and invasion capabilities. Next, M0 and M1-type macrophages were cultured in the cell culture medium of conventional A549 cells, to which AB23A was added. Subsequently, cell differentiation and inflammatory response were measured. Finally, the expression of CD18 in A549 cells was knocked down to construct NSCLC tumor-bearing mice and AB23A was applied for intragastric administration. Immunohistochemistry detected the polarization of macrophages in tumor tissues. Western blot detected the expressions of CD11b, CD18, invasion-, migration- and apoptosis-related proteins.

Results

AB23A promoted the polarization of macrophages towards M1, thus promoting the apoptosis and inhibiting the invasion and migration of A549 cells. The tumor cell culture medium induced M0 macrophages to M2, while AB23A reversed this effect. AB23A targeted CD11b/CD18 and improved the polarization of macrophages, thereby affecting tumor invasion, migration and apoptosis.

Conclusion

AB23A affected the polarization of tumor-associated macrophages through the targeted regulation of CD11b/CD18, thus inhibiting the development of lung cancer.

In Vivo Targeting of the Neurovascular Unit: Challenges and Advancements

The blood-brain barrier (BBB) is essential for the homeostasis of the central nervous system (CNS). Functions of the BBB are performed by the neurovascular unit (NVU), which consists of endothelial cells, pericytes, astrocytes, microglia, basement membrane, and neurons. NVU cells interact closely and together are responsible for neurovascular coupling, BBB integrity, and transendothelial fluid transport. Studies have shown that NVU dysfunction is implicated in several acute and chronic neurological diseases, including Alzheimer's disease, multiple sclerosis, and stroke. The mechanisms of NVU disruption remain poorly understood, partially due to difficulties in selective targeting of NVU cells. In this review, we discuss the relative merits of available protein markers and drivers of the NVU along with recent advancements that have been made in the field to increase efficiency and specificity of NVU research.

Pharmacological Properties and Molecular Targets of Alisol Triterpenoids from Alismatis Rhizoma

More than 100 protostane triterpenoids have been isolated from the dried rhizomes of Alisma species, designated Alismatis rhizoma (AR), commonly used in Asian traditional medicine to treat inflammatory and vascular diseases. The main products are the alisols, with the lead compounds alisol-A/-B and their acetate derivatives being the most abundant products in the plant and the best-known bioactive products. The pharmacological effects of Ali-A, Ali-A 24-acetate, Ali-B, Ali-B 23-acetate, and derivatives have been analyzed to provide an overview of the medicinal properties, signaling pathways, and molecular targets at the origin of those activities. Diverse protein targets have been proposed for these natural products, including the farnesoid X receptor, soluble epoxide hydrolase, and other enzymes (AMPK, HCE-2) and functional proteins (YAP, LXR) at the origin of the anti-atherosclerosis, anti-inflammatory, antioxidant, anti-fibrotic, and anti-proliferative activities. Activities were classified in two groups. The lipid-lowering and anti-atherosclerosis effects benefit from robust in vitro and in vivo data (group 1). The anticancer effects of alisols have been largely reported, but, essentially, studies using tumor cell lines and solid in vivo data are lacking (group 2). The survey shed light on the pharmacological properties of alisol triterpenoids frequently found in traditional phytomedicines.

A Review on the Molecular Mechanisms of Action of Natural Products in Preventing Bone Diseases

The drugs used for treating bone diseases (BDs), at present, elicit hazardous side effects that include certain types of cancers and strokes, hence the ongoing quest for the discovery of alternatives with little or no side effects. Natural products (NPs), mainly of plant origin, have shown compelling promise in the treatments of BDs, with little or no side effects. However, the paucity in knowledge of the mechanisms behind their activities on bone remodeling has remained a hindrance to NPs’ adoption. This review discusses the pathological development of some BDs, the NP-targeted components, and the actions exerted on bone remodeling signaling pathways (e.g., Receptor Activator of Nuclear Factor κ B-ligand (RANKL)/monocyte/macrophage colony-stimulating factor (M-CSF)/osteoprotegerin (OPG), mitogen-activated protein kinase (MAPK)s/c-Jun N-terminal kinase (JNK)/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), Kelch-like ECH-associated protein 1 (Keap-1)/nuclear factor erythroid 2–related factor 2 (Nrf2)/Heme Oxygenase-1 (HO-1), Bone Morphogenetic Protein 2 (BMP2)-Wnt/β-catenin, PhosphatidylInositol 3-Kinase (PI3K)/protein kinase B (Akt)/Glycogen Synthase Kinase 3 Beta (GSK3β), and other signaling pathways). Although majority of the studies on the osteoprotective properties of NPs against BDs were conducted ex vivo and mostly on animals, the use of NPs for treating human BDs and the prospects for future development remain promising.

Evolving Roles of Natural Terpenoids From Traditional Chinese Medicine in the Treatment of Osteoporosis

Osteoporosis (OP) is a systemic metabolic skeletal disease which can lead to reduction in bone mass and increased risk of bone fracture due to the microstructural degradation. Traditional Chinese medicine (TCM) has been applied in the prevention and treatment of osteoporosis for a long time. Terpenoids, a class of natural products that are rich in TCM, have been widely studied for their therapeutic efficacy on bone resorption, osteogenesis, and concomitant inflammation. Terpenoids can be classified in four categories by structures, monoterpenoids, sesquiterpenoids, diterpenoids, and triterpenoids. In this review, we comprehensively summarize all the currently known TCM-derived terpenoids in the treatment of OP. In addition, we discuss the possible mechanistic-of-actions of all four category terpenoids in anti-OP and assess their therapeutic potential for OP treatment.

Alisol B 23-acetate, a new promoter for cholesterol efflux from dendritic cells, alleviates dyslipidemia and inflammation in advanced atherosclerotic mice

Atherosclerosis (AS) is characterized by dyslipidemia and chronic inflammation. In the high-fat environment, the lipid metabolism of dendritic cells (DCs) is abnormal, which leads to abnormal immune function, promotes the occurrence of immune inflammatory reactions, and promotes the development of AS. Alisol B 23-acetate (23B) is a triterpenoid in the rhizomes of Alisma, which is a traditional Chinese medicine. Here, we identified cholesterol metabolism-related targets of 23B through a virtual screen, and further transcriptome analysis revealed that 23B can change antigen presentation and cholesterol metabolism pathways in cholesterol-loaded DCs. In vitro experiments confirmed that 23B promoted cholesterol efflux from ApoE^-/- DCs, reduced the expression of MHC II, CD80, and CD86, and inhibited the activation of CD4⁺ T cells and the production of inflammatory cytokines IL-12 and IFN-γ. In advanced AS mice, 23B can decrease triacylglycerol (TG) levels and increase high-density lipoprotein-cholesterol (HDL-C) levels in plasma and the expression of cholesterol efflux genes in the aorta. Neither helper T cells 1 (Th1) nor regulatory T cells (Tregs) in peripheral blood changed significantly in the presence of 23B, but 23B reduced the levels of IL-12 and IFN-γ in serum. However, 23B did not change the total cholesterol (TC) and low-density lipoprotein-cholesterol (LDL-C) levels in serum or lipid accumulation in the aorta. Moreover, 23B did not increase the production of IL-10 and TGF-β1 in vivo or in vitro. These results indicate that 23B promotes cholesterol efflux from DCs, which can improve the immune inflammatory response and contribute to controlling the inflammatory status of AS.

Lansoprazole Alone or in Combination With Gefitinib Shows Antitumor Activity Against Non-small Cell Lung Cancer A549 Cells in vitro and in vivo

Lansoprazole (Lpz) is an FDA-approved proton pump inhibitor (PPI) drug for the therapy of acid-related diseases. Aiming to explore the new application of old drugs, we recently investigated the antitumor effect of Lpz. We demonstrated that the PPI Lpz played a tumor suppressive role in non-small cell lung cancer (NSCLC) A549 cells. Mechanistically, Lpz induced apoptosis and G0/G1 cell cycle arrest by inhibiting the activation of signal transducer and activator of transcription (Stat) 3 and the phosphoinositide 3-kinase (PI3K)/Akt and Raf/ERK pathways. In addition, Lpz inhibited autophagy by blocking the fusion of autophagosomes with lysosomes. Furthermore, Lpz in combination with gefitinib (Gef) showed a synergistic antitumor effect on A549 cells, with enhanced G0/G1 cell cycle arrest and apoptosis. The combination inhibited Stat3 phosphorylation, PI3K/Akt and Raf/ERK signaling, affecting cell cycle-related proteins such as p-Rb, cyclin D1 and p27, as well as apoptotic proteins such as Bax, Bcl-2, caspase-3, and poly (ADP-ribose) polymerase (PARP). In vivo, coadministration with Lpz and Gef significantly attenuated the growth of A549 nude mouse xenograft models. These findings suggest that Lpz might be applied in combination with Gef for NSCLC therapy, but further evidence is required.

STIM1 promotes angiogenesis by reducing exosomal miR-145 in breast cancer MDA-MB-231 cells

Cancer cells secrete abundant exosomes, and the secretion can be promoted by an increase of intracellular Ca2+. Stromal interaction molecule 1 (STIM1) plays a key role in shaping Ca2+ signals. MicroRNAs (miRNAs) have been reported to be potential therapeutic targets for many diseases, including breast cancer. Recently, we investigated the effect of exosomes from STIM1-knockout breast cancer MDA-MB-231 cells (Exo-STIM1-KO), and from SKF96365-treated MDA-MB-231 cells (Exo-SKF) on angiogenesis in human umbilical vein endothelial cells (HUVECs) and nude mice. The exosomes Exo-STIM1-KO and Exo-SKF inhibited tube formation by HUVECs remarkably. The miR-145 was increased in SKF96365 treated or STIM1-knockout MDA-MB-231 cells, Exo-SKF and Exo-STIM1-KO, and HUVECs treated with Exo-SKF or Exo-STIM1-KO. Moreover, the expressions of insulin receptor substrate 1 (IRS1), which is the target of miR-145, and the downstream proteins such as Akt/mammalian target of rapamycin (mTOR), Raf/extracellular signal regulated-protein kinase (ERK), and p38 were markedly inhibited in HUVECs treated with Exo-SKF or Exo-STIM1-KO. Matrigel plug assay in vivo showed that tumor angiogenesis was suppressed in Exo-STIM1-KO, but promoted when miR-145 antagomir was added. Taken together, our findings suggest that STIM1 promotes angiogenesis by reducing exosomal miR-145 in breast cancer MDA-MB-231 cells.

The antipsychotic drug pimozide inhibits IgE-mediated mast cell degranulation and migration

BACKGROUND

Mast cells (MCs) mediate a key role in allergic diseases. Detailed studies of how the neuroleptic drug pimozide affects MC activity are lacking. The aim of this study was to investigate pimozide inhibition of immunoglobulin E (IgE)-mediated MC activation and MC-mediated allergic responses.

METHOD

MCs were stimulated with anti-dinitrophenyl (DNP) IgE antibodies and DNP-horse serum albumin (HSA) antigen (Ag), and anti-allergic pimozide effects were detected by measuring β-hexosaminidase levels. Morphological changes were observed histologically. In vivo pimozide effects were assessed in passive cutaneous anaphylaxis (PCA) and ovalbumin (OVA)-sensitized active systemic anaphylaxis mouse (ASA) model experiments. Levels of phosphorylated (p-) SYK (spleen tyrosine kinase) and MAPKs (mitogen-activated protein kinases) were detected in western blots.

RESULTS

We found that pimozide inhibited MC degranulation, reduced MC release of β-hexosaminidase dose-dependently in activated RBL-2H3 (IC₅₀: 13.52 μM) and bone marrow derived MC (BMMC) (IC₅₀: 42.42 μM), and reduced MC morphological changes. The IgE/Ag-induced migration effect was suppressed by pimozide treatment dose-dependently. Pimozide down-regulated IgE/Ag-induced phosphorylation of SYK and MAPKs in activated MCs. Moreover, pimozide attenuated allergic reactions in PCA and ASA model mice, and decreased MC populations among splenic cells.

CONCLUSIONS

The antipsychotic drug pimozide can suppress IgE-mediated MC activation in vitro and in vivo and should be considered for repurposing to suppress MC-mediated diseases.

Aurora kinase inhibitor tozasertib suppresses mast cell activation in vitro and in vivo

BACKGROUND AND PURPOSE

Mast cells are important in allergic reactions. Here, we assessed the anti-allergic effects of the anti-cancer drug tozasertib specifically regarding regulatory effects on mast cell activation.

EXPERIMENTAL APPROACH

Tozasertib effects on mast cell degranulation were determined by measuring β-hexosaminidase and histamine release and by assessing morphological changes in RBL-2H3 and mouse bone marrow-derived mast cells (BMMCs) stimulated with mouse anti-dinitrophenyl (DNP)-IgE/DNP-human serum albumin or human LAD2 cells activated with phorbol-12-myristate 13-acetate plus calcium ionophore (PMACI). Western blots were performed to detect the expression of molecules involved in NF-κB, MAPK, and Aurora kinase signalling. in vivo anti-allergic effects of tozasertib were determined in the murine IgE-mediated passive cutaneous anaphylaxis (PCA) and ovalbumin (OVA)-induced active systemic anaphylaxis (ASA) models.

KEY RESULTS

Tozasertib treatment decreased high-affinity IgE receptor (FcεRI) or PMACI-mediated degranulation in RBL-2H3 cells and in BMMCs or LAD2 cells as shown by β-hexosaminidase or histamine levels. Similarly, tozasertib prevented morphological changes in mast cells, such as particle release and F-actin reorganization. In addition, tozasertib markedly decreased expression of phosphorylated (p)-NF-κB p65, p-Erk1/2, p-p38, and p-Aurora A/B, indicating that tozasertib can inhibit the signalling pathway mediating mast cell activation. Tozasertib attenuated IgE/Ag-induced PCA dose-dependently, as shown by reduced Evans blue staining. Similarly, tozasertib reduced body temperature levels and serum histamine levels in OVA-challenged ASA mice.

CONCLUSION AND IMPLICATIONS

The Aurora kinase inhibitor tozasertib suppressed mast cell activation in vitro and in vivo. Tozasertib may be a potential drug, targeting mast cell activation, to treat allergic diseases or mastocytosis.

CDK4/6 inhibitor palbociclib suppresses IgE-mediated mast cell activation

BACKGROUND

Mast cell activation causes degranulation and release of cytokines, thereby promoting inflammation. The aim of this study was to investigate the inhibitory effect of CDK4/6 inhibition on mast cell activation in vitro and in vivo.

METHODS

RBL-2H3 rat basophilic leukemia cells (BLCs) and mouse bone marrow-derived mast cells (BMMCs) were sensitized with anti-dinitrophenol (DNP) immunoglobulin (Ig)E antibodies, stimulated with DNP-human serum albumin (HSA) antigens, and treated with the CDK4/6 inhibitor palbociclib. Histological stains were applied to reveal cytomorphological changes. Murine IgE-mediated passive cutaneous anaphylaxis (PCA) and ovalbumin (OVA)-induced active systemic anaphylaxis (ASA) models were used to examine palbociclib effects on allergic reactions in vivo. Western blots were performed to detect the expression of cell signaling molecules associated with mast cell activation.

RESULTS

Activated BLCs and BMMCs released copious granule-related mediators (histamine and β-hexosaminidase), which was reduced by palbociclib in a concentration-dependent manner. Palbociclib inhibited expression of the mast cell activation marker CD63 in activated BLCs and inhibited granule release (visualized with toluidine blue staining) while preventing morphological changes, (elongated shape maintained) and filamentous actin (F-actin) reorganization. Palbociclib suppressed molecular Lyn and/or mitogen-activated protein kinase (MAPK) signaling associated with mast cell activation in stimulated BLCs and attenuated allergic reactions in PCA mice dose dependently. Palbociclib attenuated body temperature reduction and diminished serum histamine levels in ovalbumin OVA-challenged ASA mice.

CONCLUSION

Palbociclib suppresses IgE-mediated mast cell activation in vitro and in vivo, suggesting that it may be developed into a therapy for mast cell-mediated allergic diseases via inhibition of mast cell degranulation.