Celastrol inhibits lipopolysaccharide-induced angiogenesis by suppressing TLR4-triggered nuclear factor-kappa B activation

Celastrol inhibits laser-induced choroidal neovascularization by decreasing VEGF induced proliferation and migration

AIM

To evaluate celastrol's effect on choroidal neovascularization (CNV).

METHODS

In this study, neovascular formation in vitro (tube formation and aortic ring culture) and in vivo (laser induced neovascular in mice) was treated with celastrol to evaluate this natural compound's impact on CNV. Western blot was applied to explore the possible mechanism for it. For in vitro assay, triplicate for each group was repeated at least three times. For in vivo assay, each group contains 5 mice.

RESULTS

Celastrol supressed tube formation and aortic ring sprout neovascularization. In vitro assay exhibited that celastrol inhibiting vascular endothelial growth factor (VEGF)-induced proliferation and migration of human umbilical vein endothelial cells and human choroidal endothelial cells, and by blocking VEGF signaling. Furthermore, intraperitoneal administration of celastrol significantly reduced the area of laser-induced CNV in an in vivo mouse model. By day 14, the area of CNV had decreased by 49.15% and 80.26% in the 0.1 mg/kg celastrol-treated group (n=5) and in the 0.5 mg/kg celastrol treated group (n=5), respectively, compared to the vehicle-treated group (n=5).

CONCLUSION

Celastrol inhibits CNV by inhibiting VEGF-induced proliferation and migration of vascular endothelial cells, indicating that celastrol is a potent, natural therapeutic compound for the prevention of CNV.

Antiangiogenic Phytochemicals Constituent of Diet as Promising Candidates for Chemoprevention of Cancer

Despite the extensive knowledge on cancer nature acquired over the last years, the high incidence of this disease evidences a need for new approaches that complement the clinical intervention of tumors. Interestingly, many types of cancer are closely related to dietary habits associated with the Western lifestyle, such as low fruit and vegetable intake. Recent advances around the old-conceived term of chemoprevention highlight the important role of phytochemicals as good candidates for the prevention or treatment of cancer. The potential to inhibit angiogenesis exhibited by many natural compounds constituent of plant foods makes them especially interesting for their use as chemopreventive agents. Here, we review the antitumoral potential, with a focus on the antiangiogenic effects, of phenolic and polyphenolic compounds, such as quercetin or myricetin; terpenoids, such as ursolic acid or kahweol; and anthraquinones from Aloe vera, in different in vitro and in vivo assays, and the available clinical data. Although clinical trials have failed to assess the preventive role of many of these compounds, encouraging preclinical data support the efficacy of phytochemicals constituent of diet in the prevention and treatment of cancer, but a deeper understanding of their mechanisms of action and better designed clinical trials are urgently needed.

Celastrol inhibits the proliferation and angiogenesis of high glucose-induced human retinal endothelial cells

Background

Diabetic retinopathy (DR) is one of the most common microvascular complications of diabetes. Celastrol plays a certain role in the improvement of various diabetes complications. Therefore, this study aimed to explore whether celastrol inhibited the proliferation and angiogenesis of high glucose (HG)-induced human retinal endothelial cells (hRECs) by down-regulating the HIF1/VEGF signaling pathway.

Methods

The viability and proliferation of hRECs treated with glucose, celastrol or dimethyloxallyl glycine (DMOG) were analyzed by MTT assay. The invasion and tube formation ability of hRECs treated with glucose, celastrol or DMOG were in turn detected by transwell assay and tube formation assay. The expression of HIF1α and VEGF in hRECs after indicated treatment was analyzed by Western blot analysis and RT-qPCR analysis and ICAM-1 expression in hRECs after indicated treatment was detected by immunofluorescence assay

Results

HG induction promoted the proliferation, invasion and tube formation ability and increased the expression of HIF-1α and VEGF of hRECs, which were gradually suppressed by celastrol changing from 0.5 to 2.0 μM. DMOG was regarded as a HIF1α agonist, which attenuated the effect of celastrol on HG-induced hRECs.

Conclusion

Celastrol inhibited the proliferation and angiogenesis of HG-induced hRECs by down-regulating the HIF1α/VEGF signaling pathway.

Tripterygium wilfordii: An inspiring resource for rheumatoid arthritis treatment

Tripterygium wilfordii Hook F (TwHF)-based therapy is among the most efficient and crucial therapeutics for the treatment of rheumatoid arthritis (RA), which indicates that TwHF is a potential source of novel anti-RA drugs. However, accumulating studies have observed that TwHF-based therapy induces multi-organ toxicity, which prevents the wide use of this herb in clinical practice, although several recent studies have attempted to reduce the toxicity of TwHF. Notably, our research group developed a "Clinical Practice Guideline for Tripterygium Glycosides/Tripterygium wilfordii Tablets in the Treatment of Rheumatoid Arthritis" (No. T/CACM 1337-2020) approved by the China Association of Chinese Medicine to standardize the clinical application of TwHF-based therapy and thus avoid adverse effects. Although great strides have been made toward the characterization of TwHF-based therapy and revealing its underlying pharmacological and toxicological mechanisms, several crucial gaps in knowledge remain as potential barriers to enhance its therapeutic effects on the premise of safety assurance. This review offers a global view of TwHF, ranging from its chemical constituents, quality control, clinical observations, and underlying pharmacological mechanisms to toxic manifestations and mechanisms. We focus on the important and emerging aspects of this field and highlight the major challenges and strategies for using novel techniques and approaches to gain new insights into unresolved questions. We hope that this review will improve the understanding of TwHF application and draw increasing interdisciplinary attention from clinicians that practice both Chinese and Western medicine, basic researchers, and computer scientists.

Effectively suppressed angiogenesis-mediated retinoblastoma growth using celastrol nanomicelles

Celastrol, a Chinese herbal medicine, has already shown an inhibition effect on retinoblastoma growth activity in our previous research, but its mechanism is not well understood. Angiogenesis is a main driving force in many tumors. Here, we studied whether celastrol could inhibit angiogenesis-mediated retinoblastoma growth, if so, through what mechanism. In this work, we developed celastrol-loaded polymeric nanomicelles to improve the poor water solubility of celastrol. When given an intraperitoneal injection to mice bearing human retinoblastoma xenografts, celastrol nanomicelles (CNMs, 27.2 mg/kg/2 days) significantly reduced the weight and the volume of tumors and decreased tumor angiogenesis. We found that CNMs suppressed hypoxia-induced proliferation, migration, and invasion by human umbilical vascular endothelial cells (EA.hy 926) in a dose-dependent manner. Furthermore, CNMs inhibited SO-Rb 50 cells-induced sprouting of the vessels and vascular formation in chick embryo chorioallantoic membrane assay in vitro. To understand the molecular mechanism of these activities, we assessed the signaling pathways in CoCl₂ treated EA.hy 926. CNMs inhibited the hypoxia-induced HIF-1α and VEGF. In conclusion, our results reveal that CNMs target the HIF-1α/VEGF pathway, which may be an important reason for the suppression of retinoblastoma growth and angiogenesis.

A Combined Systemic Strategy for Overcoming Cisplatin Resistance in Head and Neck Cancer: From Target Identification to Drug Discovery

Simple Summary

The efficiency of cisplatin is limited by drug resistance in head–neck cancer (HNC) patients. In this study, we established a cisplatin resistance (CR) cell model, generated CR related transcriptome profiling, and combined application of bioinformatics methodology to discover a possible way to overcome CR. Analysis of the functional pathway revealed that mitotic division is a novel mechanism significantly contributing to CR. Spindle pole body component 25 (SPC25), a kinetochore protein, was overexpressed in CR cells and significantly correlated with worse HNC patient survival. The silencing of SPC25 increased cisplatin sensitivity and reduced cancer stemness property. Integration of CR transcriptome profiling and drug database discovered a natural extract compound, celastrol, possessing a potent cytotoxic effect in CR cells to reverse CR. Thus, we combined systemic strategies to demonstrated that a novel biological process (mitotic cell division), a hub gene (SPC25), and a natural compound (celastrol) as novel strategies for the treatment of refractory HNC.

Abstract

Cisplatin is the first-line chemotherapy agent for head and neck cancer (HNC), but its therapeutic effects are hampered by its resistance. In this study, we employed systemic strategies to overcome cisplatin resistance (CR) in HNC. CR cells derived from isogenic HNC cell lines were generated. The CR related hub genes, functional mechanisms, and the sensitizing candidates were globally investigated by transcriptomic and bioinformatic analyses. Clinically, the prognostic significance was assessed by the Kaplan–Meier method. Cellular and molecular techniques, including cell viability assay, tumorsphere formation assay, RT-qPCR, and immunoblot, were used. Results showed that these CR cells possessed highly invasive and stem-like properties. A total of 647 molecules was identified, and the mitotic division exhibited a novel functional mechanism significantly related to CR. A panel of signature molecules, MSRB3, RHEB, ULBP1, and spindle pole body component 25 (SPC25), was found to correlate with poor prognosis in HNC patients. SPC25 was further shown as a prominent molecule, which markedly suppressed cancer stemness and attenuated CR after silencing. Celastrol, a nature extract compound, was demonstrated to effectively inhibit SPC25 expression and reverse CR phenotype. In conclusion, the development of SPC25 inhibitors, such as the application of celastrol, maybe a novel strategy to sensitize cisplatin for the treatment of refractory HNC.

Adipose mesenchymal stem cell-derived extracellular vesicles containing microRNA-26a-5p target TLR4 and protect against diabetic nephropathy

Diabetic nephropathy (DN) is a complication of diabetes that is increasing in prevalence in China. Extracellular vesicles (EVs) carrying microRNAs (miRs) may represent a useful tool in the development of therapies for DN. Here, we report that EVs released by adipose-derived mesenchymal stem cells (ADSCs) during DN contain a microRNA, miR-26a-5p, that suppresses DN. Using bioinformatic analyses, we identified differentially expressed miRs in EVs from ADSCs and in DN and predicted downstream regulatory target genes. We isolated mesenchymal stem cells (MSCs) from adipose tissues and collected EVs from the ADSCs. We exposed mouse glomerular podocytes and MP5 cells to high glucose (HG), ADSC-derived EVs, miR-26a-5p inhibitor/antagomir, Toll-like receptor 4 (TLR4) plasmids, or the NF-κB pathway activator (phorbol-12-myristate-13-acetate, or PMA). We used the cell counting kit-8 (CCK-8) assay and flow cytometry to investigate the impact of miR-26a-5p on cell viability and apoptosis and validated the results of these assays with in vivo experiments in nude mice. We found that in DN, miR-26a-5p is expressed at very low levels, whereas TLR4 is highly expressed. Of note, EVs from ADSCs ameliorated the pathological symptoms of DN in diabetic mice and transferred miR-26a-5p to HG-induced MP5 cells, improving viability while suppressing the apoptosis of MP5 cells. We also found that miR-26a-5p protects HG-induced MP5 cells from injury by targeting TLR4, inactivating the NF-κB pathway, and downregulating vascular endothelial growth factor A (VEGFA). Moreover, ADSC-derived EVs transferred miR-26a-5p to mouse glomerular podocytes, which ameliorated DN pathology. These findings suggest that miR-26a-5p from ADSC-derived EVs protects against DN.

Perilla frutescens Britton var. frutescens leaves attenuate dextran sulfate sodium-induced acute colitis in mice and lipopolysaccharide-stimulated angiogenic processes in human umbilical vein endothelial cells

The aim of the current study was to investigate whether the leaves of Perilla frutescens Britton var. frutescens (PL), a frequently consumed vegetable in Korea, attenuate dextran sulfate sodium (DSS)-induced acute colitis in mice and lipopolysaccharide (LPS)-stimulated angiogenic processes in human umbilical vein endothelial cells (HUVEC). In DSS-treated mice, dietary supplementation with PL mitigated DAI and colon shortening. The dietary PL also reduced colonic levels of inflammatory and angiogenic mediators, such as interleukin-1β, interleukin-6, monocyte chemoattractant protein-1, macrophage inflammatory protein-2, leukotriene B₄, inducible nitric oxide synthase, cyclooxygenase-2, basic fibroblast growth factor, and intercellular adhesion molecule-1 (ICAM-1). Treatment of HUVEC with ethanol extract of PL attenuated LPS-stimulated increases in ICAM-1 levels, monocyte adhesion, invasion, and tube formation. This study suggests that dietary PL effectively inhibited DSS-induced acute colitis in mice, and its anti-angiogenic activities may partially contribute to the inhibition.

Identification of COL1A1 as an invasion‑related gene in malignant astrocytoma

Malignant astrocytoma (MA) is the most common and severe type of brain tumor. A greater understanding of the underlying mechanisms responsible for the development of MA would be beneficial for the development of targeted molecular therapies. In the present study, the upregulated differentially expressed genes (DEGs) in MA were obtained from the Gene Expression Omnibus database using R/Bioconductor software. DEGs in different World Health Organization classifications were compared using the Venny tool and 15 genes, including collagen type I α1 chain (COL1A1) and laminin subunit γ1 (LAMC1), were revealed to be involved in the malignant progression of MA. In addition, the upregulated DEGs in MA were evaluated using functional annotations of Gene Ontology and Kyoto Encyclopedia of Genes and Genomes with the Database for Annotation, Visualization, and Integrated Discovery tool. The results indicated that invasion-associated enrichment was observed in 'extracellular matrix' (ECM), 'cell adhesion' and 'phosphoinositide 3-kinase-protein kinase B signaling pathway'. Subsequently, the analysis of the protein-protein interactions was performed using STRING and Cytoscape software, which revealed that the ECM component was the invasion-associated module and its corresponding genes included COL1A1, LAMC1 and fibronectin 1. Finally, survival Kaplan-Meier estimate was conducted using cBioportal online, which demonstrated that COL1A1 expression affected the survival of and recurrence in patients with MA. Moreover, the results of in vitro Transwell assay and western blot analysis revealed that the depleted levels of COL1A1 also decreased the expression of several proteins associated with cell invasion, including phosphorylated-signal transducer and activator of transcription 3, matrix metalloproteinase (MMP)-2, MMP-9 and nuclear factor-κB. On the whole, the present study identified the invasion-related target genes and the associated potential pathways in MA. The results indicated that COL1A1 may be a candidate biomarker for the prognosis and treatment of MA.

Ferulic Acid Rescues LPS-Induced Neurotoxicity via Modulation of the TLR4 Receptor in the Mouse Hippocampus

Microglia play a crucial role in the inflammatory brain response to infection. However, overactivation of microglia is neurotoxic. Toll-like receptor 4 (TLR4) is involved in microglial activation via lipopolysaccharide (LPS), which triggers a variety of cytotoxic pro-inflammatory markers that produce deleterious effects on neuronal cells. Ferulic acid (FA) is a phenolic compound that exerts antioxidant and anti-inflammatory effects in neurodegenerative disease. However, the manner in which FA inhibits neuroinflammation-induced neurodegeneration is poorly understood. Therefore, we investigated the anti-inflammatory effects of FA against LPS-induced neuroinflammation in the mouse brain. First, we provide evidence that FA interferes with TLR4 interaction sites, which are required for the activation of microglia-induced neuroinflammation, and further examined the potential mechanism of its neuroprotective effects in the mouse hippocampus using molecular docking simulation and immunoblot analysis. Our results indicated that FA treatment inhibited glial cell activation, p-JNK, p-NF_KB, and downstream signaling molecules, such as iNOS, COX-2, TNF-α, and IL-1β, in the mouse hippocampus and BV2 microglial cells. FA treatment strongly inhibited mitochondrial apoptotic signaling molecules, such as Bax, cytochrome C, caspase-3, and PARP-1, and reversed deregulated synaptic proteins, including PSD-95, synaptophysin, SNAP-25, and SNAP-23, and synaptic dysfunction in LPS-treated mice. These findings demonstrated that FA treatment interfered with the TLR4/MD2 complex binding site, which is crucial for evoking neuroinflammation via microglia activation and inhibited NF_KB likely via a JNK-dependent mechanism, which suggests a therapeutic implication for neuroinflammation-induced neurodegeneration.

Targeting VEGF/VEGFRs Pathway in the Antiangiogenic Treatment of Human Cancers by Traditional Chinese Medicine

Bearing in mind the doctrine of tumor angiogenesis hypothesized by Folkman several decades ago, the fundamental strategy for alleviating numerous cancer indications may be the strengthening application of notable antiangiogenic therapies to inhibit metastasis-related tumor growth. Under physiological conditions, vascular sprouting is a relatively infrequent event unless when specifically stimulated by pathogenic factors that contribute to the accumulation of angiogenic activators such as the vascular endothelial growth factor (VEGF) family and basic fibroblast growth factor (bFGF). Since VEGFs have been identified as the principal cytokine to initiate angiogenesis in tumor growth, synthetic VEGF-targeting medicines containing bevacizumab and sorafenib have been extensively used, but prominent side effects have concomitantly emerged. Traditional Chinese medicines (TCM)–derived agents with distinctive safety profiles have shown their multitarget curative potential by impairing angiogenic stimulatory signaling pathways directly or eliciting synergistically therapeutic effects with anti-angiogenic drugs mainly targeting VEGF-dependent pathways. This review aims to summarize (a) the up-to-date understanding of the role of VEGF/VEGFR in correlation with proangiogenic mechanisms in various tissues and cells; (b) the elaboration of antitumor angiogenesis mechanisms of 4 representative TCMs, including Salvia miltiorrhiza, Curcuma longa, ginsenosides, and Scutellaria baicalensis; and (c) circumstantial clarification of TCM-driven therapeutic actions of suppressing tumor angiogenesis by targeting VEGF/VEGFRs pathway in recent years, based on network pharmacology.

Celastrol synergizes with oral nifedipine to attenuate hypertension in preeclampsia: a randomized, placebo-controlled, and double blinded trial

Preeclampsia, a disease mainly manifesting as serious hypertension during pregnancy, affects expectant mothers around the globe. Celastrol, a naturally existing triterpenoid, is known to exhibit beneficial effects attenuating cardiovascular symptoms including hypertension. We here assessed the treatment outcome against preeclampsia with a combined use of celastrol and nifedipine. A total of 626 patients with preeclampsia were enrolled, screened, and assigned by random to groups receiving either nifedipine + placebo or nifedipine + celastrol orally. Time required to control hypertension as well as time before another hypertensive crisis were defined as primary end points. Secondary end points include the number of dosages required to control hypertension, as well as maternal and neonatal adverse effects. The time to control hypertension showed a marked reduction in nifedipine + celastrol group, while time before a new hypertensive crisis was significantly lengthened with the treatment, compared with the nifedipine + placebo group. The number of dosages required to control hypertension was also lower in the nifedipine + celastrol group. The two treatment groups were not statistically different regarding adverse effects, either maternal or neonatal. Results from the current study provide evidence for the potential role of celastrol serving as an effective and safe adjuvant to oral nifedipine against hypertension in patients with preeclampsia.

Celastrol and Its Role in Controlling Chronic Diseases

Celastrol, a triterpenoid derived from traditional Chinese medicinal plants, has anti-inflammatory, antioxidant, and anticancer activities. Celastrol has shown preventive/therapeutic effects in experimental models of several chronic diseases. These include, chronic inflammatory and autoimmune diseases (e.g., rheumatoid arthritis, multiple sclerosis, systemic lupus erythematosus, inflammatory bowel disease, and psoriasis), neurodegenerative disorders (e.g., Alzheimer's disease, Parkinson's disease, and Amyotrophic lateral sclerosis), atherosclerosis, obesity, Type 2 diabetes, and cancer. Celastrol modulates intricate cellular pathways and networks associated with disease pathology, and it interrupts or redirects the aberrant cellular and molecular events so as to limit disease progression and facilitate recovery, where feasible. The major cell signaling pathways modulated by celastrol include the NF-kB pathway, MAPK pathway, JAK/STAT pathway, PI3K/Akt/mTOR pathway, and antioxidant defense mechanisms. Furthermore, celastrol modulates cell proliferation, apoptosis, proteasome activity, heat-shock protein response, innate and adaptive immune responses, angiogenesis, and bone remodeling. Current understanding of the mechanisms of action of celastrol and information about its disease-modulating activities in experimental models have set the stage for testing celastrol in clinical studies as a therapeutic agent for several chronic human diseases.

Tripterygium wilfordii Inhibiting Angiogenesis for Rheumatoid Arthritis Treatment

Rheumatoid arthritis (RA) is a chronic inflammatory disease with a serious pre-vascular inflammatory phase, followed by significant increase in vessel growth. Inhibition of angiogenesis is a novel therapeutic strategy against RA. The Chinese herbal remedy Tripterygium wilfordii, Hook. f. (TwHf) has been reported to be therapeutically efficacious in the treatment of RA. Recent studies have revealed that treatment with TwHf extracts inhibit angiogenesis of RA, thereby elaborately attenuation RA symptom. This review mainly addresses the anti-angiogenesis effect of TwHf in treatment of RA.

Angiomodulators in cancer therapy: New perspectives

The formation of new blood vessels plays a crucial for the development and progression of pathophysiological changes associated with a variety of disorders, including carcinogenesis. Angiogenesis inhibitors (anti-angiogenics) are an important part of treatment for some types of cancer. Some natural products isolated from marine invertebrates have revealed antiangiogenic activities, which are diverse in structure and mechanisms of action. Many preclinical studies have generated new models for further modification and optimization of anti-angiogenic substances, and new information for mechanistic studies and new anti-cancer drug candidates for clinical practice. Moreover, in the last decade it has become apparent that galectins are important regulators of tumor angiogenesis, as well as microRNA. MicroRNAs have been validated to modulate endothelial cell migration or endothelial tube organization. In the present review we summarize the current knowledge regarding the role of marine-derived natural products, galectins and microRNAs in tumor angiogenesis.

Celastrol nanomicelles attenuate cytokine secretion in macrophages and inhibit macrophage-induced corneal neovascularization in rats

The aim of the present study was to investigate the inhibitory effects of celastrol-loaded nanomicelles (CNMs) on activated macrophage-induced corneal neovascularization (CNV) in rats and cytokine secretion in macrophages. Using an angiogenesis assay in vitro, we detected the effects of CNMs on human umbilical vein endothelial cell (HUVEC) migration and invasion. In addition, the expression levels of cytokines secreted from hypoxia-induced macrophages were assessed through cytokine array analysis. The expression of hypoxia-inducible factors-1α (HIF-1α), nuclear factor-kappa B p65 (NF-κB p65), phospho-nuclear factor-kappa B p65 (phospho-NF-κB p65), p38 mitogen-activated protein kinase (p38 MAPK), phospho-p38 MAPK, extracellular signal-regulated kinase 1/2 (ERK1/2), and phospho-ERK1/2 was analyzed by western blotting. Activated macrophages were elicited through mineral oil lumbar injection, labeled with 1,19-dioctadecyl-3-3-39,39-tetramethylindocarbocyanine (DiI) and implanted into the corneal micro-pocket to induce CNV and to assess the antiangiogenic effect in rats. CNV was morphometrically analyzed using ImageJ software. Histopathological features were evaluated by immunofluorescence immunostaining for vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) on day 2 after surgery. In the present study, the results indicated that CNMs significantly inhibited the migration and invasion of HUVECs; remarkably attenuated the expression of VEGF, tumor necrosis factor-α, interleukin-1α, monocyte chemoattractant protein 1, cytokine-induced neutrophil chemoattractant 3, and MMP-9 protein; and downregulated ERK1/2, p38 MAPK, NF-κB activation, and HIF-1α expression in macrophages. The peritoneal cells elicited using mineral oil were highly purified macrophages, and the length and area of CNV were significantly decreased in the CNMs group compared with the control group. There was a significant reduction in the expression of VEGF and MMP-9 in activated macrophages and corneal tissue after pretreatment with CNMs in this model. In conclusion, CNMs potently suppressed macrophage-induced CNV via the inhibition of VEGF and MMP-9 expression. This effect might be mediated through attenuating macrophages via HIF-1α, MAPK, and NF-κB signaling pathways.

GEN3VA: aggregation and analysis of gene expression signatures from related studies

BACKGROUND

Genome-wide gene expression profiling of mammalian cells is becoming a staple of many published biomedical and biological research studies. Such data is deposited into data repositories such as the Gene Expression Omnibus (GEO) for potential reuse. However, these repositories currently do not provide simple interfaces to systematically analyze collections of related studies.

RESULTS

Here we present GENE Expression and Enrichment Vector Analyzer (GEN3VA), a web-based system that enables the integrative analysis of aggregated collections of tagged gene expression signatures identified and extracted from GEO. Each tagged collection of signatures is presented in a report that consists of heatmaps of the differentially expressed genes; principal component analysis of all signatures; enrichment analysis with several gene set libraries across all signatures, which we term enrichment vector analysis; and global mapping of small molecules that are predicted to reverse or mimic each signature in the aggregate. We demonstrate how GEN3VA can be used to identify common molecular mechanisms of aging by analyzing tagged signatures from 244 studies that compared young vs. old tissues in mammalian systems. In a second case study, we collected 86 signatures from treatment of human cells with dexamethasone, a glucocorticoid receptor (GR) agonist. Our analysis confirms consensus GR target genes and predicts potential drug mimickers.

CONCLUSIONS

GEN3VA can be used to identify, aggregate, and analyze themed collections of gene expression signatures from diverse but related studies. Such integrative analyses can be used to address concerns about data reproducibility, confirm results across labs, and discover new collective knowledge by data reuse. GEN3VA is an open-source web-based system that is freely available at: http://amp.pharm.mssm.edu/gen3va .

TAZ promotes cell growth and inhibits Celastrol-induced cell apoptosis

Hippo pathway is a highly conservative signalling pathway related to the development of organisms, which has been demonstrated to be strongly linked to the tumorigenesis and tumour progression. As the major downstream effector of Hippo pathway, yes-associated protein (YAP), is a transcriptional activator of target genes that are involved in cell proliferation and survival. As an oncogene, YAP can promote cell growth and inhibit cell apoptosis. Another major downstream effector of Hippo pathway, transcriptional co-activators with PDZ-binding motif (TAZ), is nearly 60% homologous with YAP. In the present study, we assume that TAZ probably has the similar function to YAP. To test this issue, we established an inducible and a stable expression system of TAZ in T-Rex-293 and HEK293 cells respectively. The results of cell growth curves, colony formation assay and tumour xenograft growth showed that overexpression of TAZ could promote cell growth in vitro and in vivo Meanwhile, we found that up-regulated expression of TAZ could partially restore Celastrol-induced cell apoptosis. Induced overexpression of TAZ could up-regulate its target genes including ankyrin repeat domain-containing protein (ANKRD), cysteine-rich 61 (CYR61) and connective tissue growth factor (CTGF), increase the expression of B-cell lymphoma-2 (Bcl-2), decrease the expression of Bcl-2 associated X protein (Bax) and activate the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway, which may be the mechanism underlying anti-apoptosis of TAZ. All these findings indicated that TAZ acts as an oncogene that could be a key regulator of cell proliferation and apoptosis.

Control of autoimmune inflammation by celastrol, a natural triterpenoid

Celastrol is a bioactive compound derived from traditional Chinese medicinal herbs of the Celastraceae family. Celastrol is known to possess anti-inflammatory and anti-oxidant activities. Our studies have highlighted the immunomodulatory attributes of celastrol in adjuvant-induced arthritis (AA), an experimental model of human rheumatoid arthritis (RA). RA is an autoimmune disease characterized by chronic inflammation of the synovial lining of the joints, leading eventually to tissue damage and deformities. Identification of the molecular targets of celastrol such as the NF-κB pathway, MAPK pathway, JAK/STAT pathway and RANKL/OPG pathway has unraveled its strategic checkpoints in controlling arthritic inflammation and tissue damage in AA. The pathological events that are targeted and rectified by celastrol include increased production of pro-inflammatory cytokines; an imbalance between pathogenic T helper 17 and regulatory T cells; enhanced production of chemokines coupled with increased migration of immune cells into the joints; and increased release of mediators of osteoclastic bone damage. Accordingly, celastrol is a promising candidate for further testing in the clinic for RA therapy. Furthermore, the results of other preclinical studies suggest that celastrol might also be beneficial for the treatment of a few other autoimmune diseases besides arthritis.

Naringin inhibits lipopolysaccharide-induced damage in human umbilical vein endothelial cells via attenuation of inflammation, apoptosis and MAPK pathways

Endothelial cell activation, injury and dysfunction have been regarded as one of the initial key events in the pathogenesis of atherosclerosis. Lipopolysaccharide (LPS), an important mediator of inflammation, can cause endothelial cell damage and apoptosis. Naringin (Nar), one major flavanone glycoside from citrus fruits, shows various pharmacological actions, but the effect of Nar on LPS-induced damage in human umbilical vein endothelial cells (HUVECs) remains unknown. The present results showed that Nar significantly improved the survival rate of HUVECs, and decreased reactive oxygen species and intracellular Ca(2+) levels caused by LPS compared with model group. In addition, Nar obviously decreased cytochrome c release from mitochondria into cytosol. Moreover, Nar significantly down-regulated the protein or mRNA levels of IL-1, IL-6, TNF-α, VCAM-1, ICAM-1, NF-κB, AP-1, cleaved-3,-7,-9, p53, Bak and Bax, and up-regulated the expressions of Bcl-xl, Bcl-2 to suppress inflammation and apoptosis. Furthermore, Nar obviously inhibited phosphorylation levels of JNK, ERK and p38 MAPK. In conclusion, Nar exhibited potent effects against LPS-induced damage in HUVECs through the modulation of oxidative stress, inflammation, apoptosis and MAPK pathways, which should be developed as a potent candidate for the treatment of atherosclerosis in the future.

Celastrol blocks binding of lipopolysaccharides to a Toll-like receptor4/myeloid differentiation factor2 complex in a thiol-dependent manner

ETHNOPHARMACOLOGICAL RELEVANCE

Tripterygium wilfordii (lei gong teng; Thunder of God Vine), which belongs to the Celastraceae family, has long been used in traditional Chinese medicine to treat inflammation and rheumatoid arthritis. Celastrol is a bioactive compound isolated from T. wilfordii.

AIM OF THE STUDY

We investigated whether celastrol suppressed binding of lipopolysaccharides (LPS) to myeloid differentiation factor 2 (MD2), thereby downregulating Toll-like receptor4 (TLR4) activation in mouse primary macrophages.

MATERIALS AND METHODS

Cytokine expression was determined by polymerase chain reaction analysis and enzyme-linked immunosorbent assay in bone marrow-derived primary macrophages (BMDMs). The kinase activity of tank-binding kinase 1 (TBK1) was examined by a luciferase reporter assay and an in vitro kinase assay. LPS binding to MD2 was examined by an in vitro binding assay and confocal microscopy analysis.

RESULTS

Celastrol reduced LPS-induced expression of inflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-12, and IL-1β, at both the mRNA and protein levels in BMDMs. Celastrol suppressed LPS binding to MD2, as shown by the in vitro binding assay, whereas it did not inhibit TBK1. In addition, co-localization of LPS with MD2 in BMDMs was blocked by celastrol. The inhibitory effects of celastrol on LPS binding to MD2 were reversed by thiol donors (N-acetyl-L-cysteine and dithiothreitol), suggesting that the thiol reactivity of celastrol contributes to its inhibitory effects on TLR4 activation in macrophages.

CONCLUSION

Our results demonstrate that celastrol suppresses TLR4 activation through the inhibition of LPS binding to the TLR4/MD2 complex. These results provide a novel mechanism of action by which celastrol contributes to the anti-inflammatory activity of T. wilfordii.

Lipopolysaccharide Effect on Vascular Endothelial Factor and Matrix Metalloproteinases in Leukemic Cell Lines In vitro

Background:

Angiogenesis, the process of new vessels generation, plays a critical role in tumor invasion and metastasis. Vascular Endothelial Growth Factor (VEGF), as a cytokine, and Matrix Metalloproteinases (MMPs), has been the important factors that involved in angiogenesis. Lipopolysaccharide (LPS) has an essential effect on angiogenesis.

Objectives:

In this study the effect of LPS on VEGF production and MMP-2/MMP-9 activity in two leukemic cell lines has been assessed in vitro.

Materials and Methods:

Human leukemic U937 and THP1 cells were cultured in complete RPMI medium. Then the cells at the exponential growth phase were incubated with different concentrations of LPS (0 - 4 μg/mL) for 48 hours. Then the level of VEGF production and MMP-2/MMP-9 activity in cell culture supernatants were evaluated with the ELISA standard kits and gelatin zymography respectively.

Results:

U937 cells have produced a large amount of VEGF without any stimulus and LPS has not shown any substantial effect on VEGF production by these cells. However THP1 cells have produced a small amount of VEGF without stimulation and LPS significantly has increased VEGF production in these cells dose-dependently. Moreover LPS significantly has augmented the MMP-2/MMP-9 activity in the both leukemic cell lines in a dose-dependent manner.

Conclusions:

Our results have shown that LPS might be a potential inducer/enhancer of VEGF production and MMP-2/MMP-9 activity (angiogenic factors) in leukemia. Moreover the LPS effect on angiogenesis might be in part, due to its stimulatory effects on VEGF and MMPs. Overall LPS-stimulated leukemic cells might be good models for study and planning the useful therapeutic approaches for angiogenesis- dependent diseases.

Broad targeting of angiogenesis for cancer prevention and therapy

Deregulation of angiogenesis – the growth of new blood vessels from an existing vasculature – is a main driving force in many severe human diseases including cancer. As such, tumor angiogenesis is important for delivering oxygen and nutrients to growing tumors, and therefore considered an essential pathologic feature of cancer, while also playing a key role in enabling other aspects of tumor pathology such as metabolic deregulation and tumor dissemination/metastasis. Recently, inhibition of tumor angiogenesis has become a clinical anti-cancer strategy in line with chemotherapy, radiotherapy and surgery, which underscore the critical importance of the angiogenic switch during early tumor development. Unfortunately the clinically approved anti-angiogenic drugs in use today are only effective in a subset of the patients, and many who initially respond develop resistance over time. Also, some of the anti-angiogenic drugs are toxic and it would be of great importance to identify alternative compounds, which could overcome these drawbacks and limitations of the currently available therapy. Finding “the most important target” may, however, prove a very challenging approach as the tumor environment is highly diverse, consisting of many different cell types, all of which may contribute to tumor angiogenesis. Furthermore, the tumor cells themselves are genetically unstable, leading to a progressive increase in the number of different angiogenic factors produced as the cancer progresses to advanced stages. As an alternative approach to targeted therapy, options to broadly interfere with angiogenic signals by a mixture of non-toxic natural compound with pleiotropic actions were viewed by this team as an opportunity to develop a complementary anti-angiogenesis treatment option. As a part of the “Halifax Project” within the “Getting to know cancer” framework, we have here, based on a thorough review of the literature, identified 10 important aspects of tumor angiogenesis and the pathological tumor vasculature which would be well suited as targets for anti-angiogenic therapy: (1) endothelial cell migration/tip cell formation, (2) structural abnormalities of tumor vessels, (3) hypoxia, (4) lymphangiogenesis, (5) elevated interstitial fluid pressure, (6) poor perfusion, (7) disrupted circadian rhythms, (8) tumor promoting inflammation, (9) tumor promoting fibroblasts and (10) tumor cell metabolism/acidosis. Following this analysis, we scrutinized the available literature on broadly acting anti-angiogenic natural products, with a focus on finding qualitative information on phytochemicals which could inhibit these targets and came up with 10 prototypical phytochemical compounds: (1) oleanolic acid, (2) tripterine, (3) silibinin, (4) curcumin, (5) epigallocatechin-gallate, (6) kaempferol, (7) melatonin, (8) enterolactone, (9) withaferin A and (10) resveratrol. We suggest that these plant-derived compounds could be combined to constitute a broader acting and more effective inhibitory cocktail at doses that would not be likely to cause excessive toxicity. All the targets and phytochemical approaches were further cross-validated against their effects on other essential tumorigenic pathways (based on the “hallmarks” of cancer) in order to discover possible synergies or potentially harmful interactions, and were found to generally also have positive involvement in/effects on these other aspects of tumor biology. The aim is that this discussion could lead to the selection of combinations of such anti-angiogenic compounds which could be used in potent anti-tumor cocktails, for enhanced therapeutic efficacy, reduced toxicity and circumvention of single-agent anti-angiogenic resistance, as well as for possible use in primary or secondary cancer prevention strategies.

Design, synthesis and biological evaluation of C(6)-indole celastrol derivatives as potential antitumor agents

A new class of C(6)-indole substituted celastrol derivatives were designed and synthesized. Among all these synthesized molecules, compound 4f and 4h displayed excellent in vitro antiproliferative activities against Bel7402 cancer cells.