VEGFR tyrosine kinase inhibitor II (VRI) induced vascular insufficiency in zebrafish as a model for studying vascular toxicity and vascular preservation

Characterization of a polysaccharide from Amauroderma rugosum and its proangiogenic activities in vitro and in vivo

Amauroderma rugosum (AR), also known as "Blood Lingzhi" in Chinese, is a basidiomycete belonging to the Ganodermataceae family. Four polysaccharide fractions were systematically isolated and purified from AR. Subsequently, their compositions were examined and analyzed via high-performance gel permeation chromatography (HPGPC), analysis of the monosaccharide composition, Fourier-transform infrared spectroscopy (FT-IR), and 1H nuclear magnetic resonance (NMR). The zebrafish model was then used to screen for proangiogenic activities of polysaccharides by inducing vascular insufficiency with VEGF receptor tyrosine kinase inhibitor II (VRI). The third fraction of AR polysaccharides (PAR-3) demonstrated the most pronounced proangiogenic effects, effectively ameliorating VRI-induced intersegmental vessel deficiency in zebrafish. Concurrently, the mRNA expression levels of vascular endothelial growth factor (VEGF)-A and VEGF receptors were upregulated by PAR-3. Moreover, the proliferation, migration, invasion, and tube formation of human umbilical vein endothelial cells (HUVECs) were also stimulated by PAR-3, consistently demonstrating that PAR-3 possesses favorable proangiogenic properties. The activation of the Akt, ERK1/2, p38 MAPK, and FAK was most likely the underlying mechanism. In conclusion, this study establishes that PAR-3 isolated from Amauroderma rugosum exhibits potential as a bioresource for promoting angiogenesis.

A new invertebrate NPY-like polypeptide, ZoaNPY, from the Zoanthus sociatus, as a novel ligand of human NPY Y2 receptor rescues vascular insufficiency via PLC/PKC and Src- FAK-dependent signaling pathways

Our recent multi-omics studies have revealed rich sources of novel bioactive proteins and polypeptides from marine organisms including cnidarians. In the present study, we initially conducted a transcriptomic analysis to review the composition profile of polypeptides from Zoanthus sociatus. Then, a newly discovered NPY-like polypeptide-ZoaNPY was selected for further in silico structural, binding and virtually pharmacological studies. To evaluate the pro-angiogenic effects of ZoaNPY, we employed an in vitro HUVECs model and an in vivo zebrafish model. Our results indicate that ZoaNPY, at 1-100 pmol, enhances cell survival, migration and tube formation in the endothelial cells. Besides, treatment with ZoaNPY could restore a chemically-induced vascular insufficiency in zebrafish embryos. Western blot results demonstrated the application of ZoaNPY could increase the phosphorylation of proteins related to angiogenesis signaling including PKC, PLC, FAK, Src, Akt, mTOR, MEK, and ERK1/2. Furthermore, through molecular docking and surface plasmon resonance (SPR) verification, ZoaNPY was shown to directly and physically interact with NPY Y2 receptor. In view of this, all evidence showed that the pro-angiogenic effects of ZoaNPY involve the activation of NPY Y2 receptor, thereby activating the Akt/mTOR, PLC/PKC, ERK/MEK and Src- FAK-dependent signaling pathways. Furthermore, in an excision wound model, the treatment with ZoaNPY was shown to accelerate the wound healing process in mice. Our findings provide new insights into the discovery and development of novel pro-angiogenic drugs derived from NPY-like polypeptides in the future.

Dual effect of aucubin on promoting VEGFR2 mediated angiogenesis and reducing RANKL-induced bone resorption

BACKGROUND

Angiogenesis is regarded as a critical role in bone repair and regeneration, involving in pathological bone disorders such as osteoporosis. Aucubin, an iridoid glycoside primarily derived from Eucommia ulmoides, is reported to inhibit osteoclast activity, enhance bone formation and promote angiogenesis in osteoporosis models. Our study is to further investigate the anti-osteoporosis effect of aucubin in transgenic medaka, and the pro-angiogenic effect of aucubin and its mechanism of action both in vivo and in vitro.

METHODS

The anti-osteoporosis effect of aucubin was confirmed by using RANKL-stimulated bone resorption transgenic medaka. The pro-angiogenic effect of aucubin in vivo was investigated using vascular endothelial growth factor (VEGF) tyrosine kinase inhibitor II (VRI)-induced vascular insufficient transgenic zebrafish model. Furthermore, endothelial cell proliferation, migration, tube formation and the mechanisms were evaluated to identify the pro-angiogenic effect of aucubin in normal and su5416-injured human umbilical vein endothelial cells (HUVECs).

RESULTS

Aucubin decreased the resorption of the mineralized bone matrix and centra degradation in heat-shocked transgenic col10α1:nlGFP/rankl:HSE:CFP medaka. Moreover, aucubin reversed VRI-induced vascular insufficiency in zebrafish through regulating flt1, kdr, kdrl, vegfaa, ang-1, ang-2, tie1 and tie2 mRNA expressions in Tg(fli1a:EGFP)y1 or AB wild type zebrafish. Aucubin promoted cell proliferation by upregulating p-mTOR, p-Src, p-MEK, p-Erk1/2, p-Akt and p-FAK in HUVECs. Furthermore, aucubin exhibited a pro-angiogenic effect on su5416-injured HUVECs by promoting their proliferation, migration, and tube formation through regulating the phosphorylation of VEGFR2, MEK, ERK and the ratio of Bcl2-Bax.

CONCLUSION

Aucubin could reduce bone resorption in RANKL-induced osteoporosis medaka by live imaging. Meanwhile, aucubin exhibited a protective effect in VRI-induced vascular insufficient zebrafish by regulating VEGF-VEGFR and Ang-Tie signaling pathways. Additionally, aucubin promoted the proliferation, migration and tube formation of HUVECs probably by mediating VEGFR2/MEK/ERK, Akt/mTOR and Src/FAK signalling pathways. This study further indicated the dual effect of aucubin on angiogenesis and osteogenesis which may be beneficial to its treatment of osteoporosis.

Buxue Yimu Pills improve angiogenesis and blood flow in experimental zebrafish and rat models

ETHNOPHARMACOLOGICAL RELEVANCE

Buxue Yimu Pills (BYP) is a well-known traditional Chinese medicine prescription which is clinical used in gynecology and obstetrics, and is documented to exhibit therapeutic potential to defective angiogenesis and impaired blood flow.

AIM OF THE STUDY

This study aimed to investigate the effects and biological mechanisms of BYP in improvement of defective angiogenesis and impaired blood flow which represent major health issues associated with various diseases including postpartum or abortion complications.

MATERIALS AND METHODS

In this study, VEGFR tyrosine kinase inhibitor II (VRI) was used to establish blood vessel loss model in Tg(fli-1a:EGFP) zebrafish embryos. Blood vessel loss was calculated, and quantitative real-time PCR (qRT-PCR) assay was performed to detect gene expression. Mifepristone and misoprostol were applied to construct a medical-induced incomplete abortion rats model. Whole blood viscosity indexes, hemorheology and coagulation function of the rats were investigated. Immunohistochemistry analysis was used for evaluation of the uterine tissues.

RESULTS

BYP treatment significantly promoted angiogenesis as evidenced by the restoration of VRI-induced blood vessel loss in zebrafish embryos. BYP treatment effectively reversed VRI-induced down-regulation of the VEGFRs (Kdr, Kdrl and Flt1). Furthermore, BYP administration significantly suppressed the increase of whole blood viscosity indexes, and remarkably shortened the levels of prothrombin time and activated partial thromboplastin time in the medical-induced incomplete abortion rats, indicating the improvement of hemorheology and coagulation function. Immunohistochemistry analysis suggested that BYP administration increased the expression level of VEGFR2 in uterus tissues of the rats.

CONCLUSION

BYP exhibits therapeutic effects in promoting angiogenesis and blood circulation, and mitigating blood stasis, supporting its clinical application for postpartum or abortion complications.

Elaborate the Mechanism of Ancient Classic Prescriptions (Erzhi Formula) in Reversing GIOP by Network Pharmacology Coupled with Zebrafish Verification

Osteoporosis is a degenerative disease that endangers human health. At present, chemical drugs used for osteoporosis have serious side effects. Therefore, it is valuable to search herbs with high safety and good curative effect in antiosteoporosis. Erzhi formula (EZF), an ancient classic compound, has been reported to have a beneficial effect in antiosteoporosis, but its mechanism is unclear. In this paper, the active compounds of EZF were found in Systems Pharmacology Database, and gene targets related to osteoporosis were obtained in GeneCards. The GO functional and KEGG pathway enrichment analysis were performed by Metascape. The network of “components-targets-signal pathway” was constructed by Cytoscape. Next, molecular docking between the active components and hub genes related to the PI3K-Akt signaling pathway was conducted by Autodock. In the verification experiment, the zebrafish induced by prednisolone (PNSL) was used to reproduce glucocorticoid-induced osteoporosis (GIOP) model, and then the reversal effects of EZF were systematically evaluated according to the behavior, skull staining area, bone mineralization area (BMA), average optical density (AOD), and cumulative optical density (COD). Finally, it was shown that 24 components in EZF could regulate 39 common gene targets to exert antiosteoporosis effect. Besides, the main regulatory mechanisms of EZF were 4 signaling pathways: PI3K-Akt, JAK-STAT, AGE-RAGE, and cancer pathway. In PI3K-Akt signaling pathway, wedelolactone, dimethyl wedelolactone, specnuezhenide, ursolic acid, acacetin, beta-sitosterol, apigenin, and kaempferol can bind tightly with EGF, IL-2, and IL-4 genes. Compared with the model group, the moving distance, swimming speed, and cumulative swimming time of zebrafish in EZF group were significantly increased (P < 0.05). Meanwhile, the BMA and COD of zebrafish were significantly improved after the intervention of EZF (P < 0.05). In summary, the 24 components of EZF exert their antiosteoporosis effects by regulating 39 related gene targets, among which the PI3K signaling pathway is crucial. EZF can promote bone formation and reversed GIOP through “multicomponent/multitarget/multipathway” and the medium dose of EZF may be the most suitable concentration for the treatment of GIOP in zebrafish model.

Lemnalemnanes A-C, Three Rare Rearranged Sesquiterpenoids from the Soft Corals Paralemnalia thyrsoides and Lemnalia sp

Three novel sesquiterpenoids, lemnalemnanes A-C (1-3), were obtained from marine soft corals Paralemnalia thyrsoides and Lemnalia sp. Their structures were determined by 1D/2D NMR spectroscopy, HRESIMS, single-crystal X-ray diffraction analysis (Cu Kα), Mosher's method, and ECD quantum chemistry calculations. Lemnalemnane A (1) possessed an intriguing basket-like structure with a spiro[bicyclo[3.3.1]nonane-furan core, while lemnalemnanes B (2) and C (3) exhibited unusual 6/6/5 and 6/5/5 carbon skeletons, respectively. In the proposed biosynthesis pathway, 1-3 were suspected to originate from the same precursor, 4-O-deacetylparalemnolin D (4), a compound coisolated from both aforementioned species. Furthermore, lemnalemnane C (3) exhibited strong in vivo promoting-angiogenesis activity.

Huiyang Shengji decoction promotes wound healing in diabetic mice by activating the EGFR/PI3K/ATK pathway

Background

Common chronic wounds include diabetic ulcers, venous ulcers, and pressure ulcers. The traditional Chinese medicine Huiyang Shengji decoction (HYSJD) has been shown to promote the healing of diabetic chronic wounds, however, its pharmacological mechanism is still unclear.

Purpose

This study aimed to determine the mechanism of HYSJD in promoting the healing of diabetic chronic skin ulcers.

Methods

Ultra-performance liquid chromatography was combined with tandem mass spectrometry (UPLC-MS/MS) to analyze the main components of HYSJD and the absorbed components in mouse serum at 30 min after oral administration of HYSJD. db/db mouse models for chronic skin ulcers were constructed by full-thickness skin resection. Wound tissues at day 7 post wound formation were used to perform microarray analysis of growth factors and chemokine expression. GO and KEGG enrichment analysis was performed on differentially expressed proteins. ELISA assays were used to measure differential expressed cytokines in the serum and Western blot analysis was used to determine the expression levels of related pathway proteins in the skin wounds.

Results

UPLC-MS/MS analysis showed that the main chemical components of HYSJD were flavonoids, terpenes, alkaloids, phenylpropanoids, and carbohydrates. At 30 min after oral administration of HYSJD, five absorbed components were detected in the serum, these included formononetin, calycosin, hypaconitine, calycosin-7-glucoside, and sinapic acid. HYSJD was found to increase the wound healing rate in chronic skin ulcers in db/db mice at days 3, 7, and 14 post wound formation, and promote the proliferation of epidermal cells. Two proteins that were differentially expressed between the different groups, i.e., IGF-1 and EGFR, were further validated. Serum ELISA assays showed that serum EGFR in the HYSJD treatment group was significantly increased. KEGG pathway analysis suggested that the PI3K/AKT pathway involved in HYSJD promoting the proliferation of epidermal cells in chronic wounds in db/db mice. Experimental verification showed that HYSJD activated the PI3K/AKT signaling pathway in mouse wound skin.

Conclusion

HYSJD promotes the proliferation of epidermal cells in chronic diabetic wounds by increasing EGFR expression in the wounds and activating the PI3K/AKT signaling pathway. Our study provides an experimental basis for the pharmacological mechanism of HYSJD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13020-021-00497-0.

Crocetin and Its Glycoside Crocin, Two Bioactive Constituents From Crocus sativus L. (Saffron), Differentially Inhibit Angiogenesis by Inhibiting Endothelial Cytoskeleton Organization and Cell Migration Through VEGFR2/SRC/FAK and VEGFR2/MEK/ERK Signaling Pathways

Crocetin and crocin are two important carotenoids isolated from saffron (Crocus sativus L.), which have been used as natural biomedicines with beneficial effects for improving the suboptimal health status associated with abnormal angiogenesis. However, the anti-angiogenic effects and underlying mechanisms of the effects of crocetin and crocin have not been investigated and compared. The anti-angiogenic effects of crocetin and crocin were tested on human umbilical vein endothelial cells (HUVECs) in vitro, and in zebrafish in vivo. In vivo, crocetin (20 μM) and crocin (50 and 100 μM) significantly inhibited subintestinal vein vessels formation, and a conversion process between them existed in zebrafish, resulting in a difference in their effective concentrations. In the HUVEC model, crocetin (10, 20 and 40 μM) and crocin (100, 200 and 400 μM) inhibited cell migration and tube formation, and inhibited the phosphorylation of VEGFR2 and its downstream pathway molecules. In silico analysis further showed that crocetin had a higher ability to bind with VEGFR2 than crocin. These results suggested that crocetin was more effective than crocin in inhibiting angiogenesis through regulation of the VEGF/VEGFR2 signaling pathway. These compounds, especially crocetin, are potential candidate natural biomedicines for the management of diseases associated with abnormal blood vessel growth, such as age-related macular degeneration.

Evaluation of VEGF mediated pro-angiogenic and hemostatic effects and chemical marker investigation for Typhae Pollen and its processed product

ETHNOPHARMACOLOGICAL RELEVANCE

Typhae Pollen (TP) is a well-known Traditional Chinese Medicine (TCM) to remove blood stasis. Carbonized Typhae Pollen (CTP), a processed product of TP after being stir-fried, has been widely applied to clinical practice with its capability of hemostasis. However, the underlying mechanism of TP and CTP are still not fully elucidated and discrimination against TP and CTP remains a challenge.

AIM OF STUDY

The aim of this study is to investigate whether TP could remove blood stasis by promoting angiogenesis and the process of carbonizing it could enhance hemostatic effect. Meanwhile, some chemical markers for quality control of CTP had better to be found.

MATERIAL AND METHODS

The changes of constituents between TP and CTP were analyzed by UPLC-QTOF-MS/MS. We investigated pro-angiogenic and hemostatic effects of TP and CTP in two zebrafish models: VRI-induced ISV insufficiency model and Ator-induced cerebral hemorrhage model. Subsequently, quantitative real-time PCR (qRT-PCR) was applied to investigate the mechanism of pharmacological effects. Finally, chemometric method was applied to find chemical markers.

RESULTS

A total of 19 compounds were identified in qualitative analysis. The loss rate of each compound was calculated and compared. Two compounds (huaicarbon A/B) could only be detected in CTP and the content of flavonoid glycosides in CTP was significantly decreased compared with TP. The average content of the three identified flavonoid aglycones (quercetin, isorhamnetin and kaempferol) was increased about 30 percent in CTP. TP promoted pro-angiogenesis by up-regulating the expression of VEGFA, flt1 and kdr. After heating process, the pro-angiogenic activity was reduced and hemostatic activity was enhanced in CTP. Then qRT-PCR analysis found that CTP could significantly up-regulate the expression of VEGFA and vWF. In the discovery of markers, 6 chemical markers for discrimination of TP and CTP were obtained by chemometric method.

CONCLUSION

Our research indicated that the pro-angiogenic activity of TP was involved in VEGF signaling pathway. After processing, hemostatic activity of CTP has been enhanced by up-regulating the expression of VEGFA and vWF. A chemical marker database was established to provide a scientific evidence for quality control, mechanism and the clinical application of TP and CTP.

Forchlorfenuron (CPPU) causes disorganization of the cytoskeleton and dysfunction of human umbilical vein endothelial cells, and abnormal vascular development in zebrafish embryos

Forchlorfenuron (CPPU) has been used worldwide, to boost size and improve quality of various agricultural products. CPPU and its metabolites are persistent and have been detected frequently in fruits, water, sediments, and organisms in aquatic systems. Although the public became aware of CPPU through the exploding watermelon scandal of 2011 in Zhenjiang, China, little was known of its potential effects on the environment and wildlife. In this study, adverse effects of CPPU on developmental angiogenesis and vasculature, which is vulnerable to insults of persistent toxicants, were studied in vivo in zebrafish embryos (Danio rerio). Exposure to 10 mg CPPU/L impaired survival and hatching, while development was hindered by exposure to 2.5 mg CPPU/L. Developing vascular structure, including common cardinal veins (CCVs), intersegmental vessels (ISVs) and sub-intestinal vessels (SIVs), were significantly restrained by exposure to CPPU, in a dose-dependent manner. Also, CPPU caused disorganization of the cytoskeleton. In human umbilical vein endothelial cells (HUVECs), CPPU inhibited proliferation, migration and formation of tubular-like structures in vitro. Results of Western blot analyses revealed that exposure to CPPU increased phosphorylation of FLT-1, but inhibited phosphorylation of FAK and its downstream MAPK pathway in HUVECs. In summary, CPPU elicited developmental toxicity to the developing endothelial system of zebrafish and HUVECs. This was do, at least in part due to inhibition of the FAK/MAPK signaling pathway rather than direct interaction with the VEGF receptor (VEGFR).

Calycosin: a Review of its Pharmacological Effects and Application Prospects

Introduction: Calycosin (CA), a typical phytoestrogen extracted from root of Astragalus membranaceus. On the basis of summarizing the pharmacological and pharmacokinetic studies of CA in recent years, we hope to provide useful information for CA about treating different diseases and to make suggestions for future research.Areas covered: We collected relevant information (January 2014 to March 2020) on CA via the Internet database. Keywords searched includ pharmacology, pharmacokinetics and toxicology, and the number of effective references was 118. CA is a phytoestrogen with wide range of pharmacological activities. By affecting PI3K/Akt/mTOR, WDR7-7-GPR30, Rab27B-β-catenin-VEGF, etc. signaling pathway, CA showed the effect of anticancer, anti-inflammatory, anti-osteoporosis, neuroprotection, hepatoprotection, etc. Therefore, CA is prospective to be used in the treatment of many diseases.Expert opinion: Research shows that CA has a therapeutic effect on a variety of diseases. We think CA is a promising natural medicine. Therefore, we propose that the research directions of CA in the future include the following. Carrying out clinical research trials in order to find the most suitable medicinal concentration for different diseases; Exploring the synergistic mechanism of CA in combination with other drugs; Exploring ways to increase the blood circulation concentration of CA.

Lemnardosinanes A-I: New Bioactive Sesquiterpenoids from Soft Coral Lemnalia sp

Two rearranged nardosinane sesquiterpenoids with novel carbon skeletons, lemnardosinanes A (1) and B (2), and seven new nardosinane-related sesquiterpeniod lemnardosinanes C-I (3-9), together with a known compound 6,7-seco-13-nornardosinan (10), were isolated from the soft coral Lemnalia sp. collected from Xisha Islands of the South China Sea. Their structures were elucidated by comprehensive spectroscopic analyses, Mosher's method, Mo₂(OAc)₄-induced circular dichroism experiment, and quantum chemical calculations. Plausible biosynthetic pathways of 1-10 were proposed. Compounds 1 and 10 displayed in vivo angiogenesis promoting activity in a zebrafish model. Compounds 3 and 4 exhibited antiviral activity against the H1N1 virus with IC₅₀ values of 10.9 and 41.5 μM, respectively.

Orbencarb induces lethality and organ malformation in zebrafish embryos during development

Thiocarbamates are one of the components of pesticides that target weeds by inhibiting adenosine triphosphate (ATP) synthesis. Orbencarb, one of the isomeric thiocarbamates applied to wheat, maize, and soybean, has been found to have toxic effects on mammals and marine ecosystems. Although the toxicity ranges of orbencarb in different organisms are known, specific studies on the environmental contamination and harmful effects of orbencarb on non-target organisms are scarce. In this study, we observed that orbencarb induced embryotoxicity during zebrafish development as well as apoptosis and reactive oxygen species (ROS) production in the intestine. It was further observed that orbencarb decreased the viability of the embryos and simultaneously affected the heart rate and vessel formation. Orbencarb decreased the mRNA levels of ccnd1, ccne1, cdk2, and cdk6 and induced abnormal development of the eyes, brain, yolk sac, and spinal cord in zebrafish embryos. Orbencarb also hampered vasculogenesis in the zebrafish embryos by inhibiting the mRNA expression of flt1, flt4, kdr, and vegfc. Collectively, these results suggested that orbencarb is embryotoxic and disrupts the normal growth of zebrafish embryos by inducing the generation of ROS and hampering vasculogenesis.

Pro-angiogenic activity of Tongnao decoction on HUVECs in vitro and zebrafish in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Tongnao Decoction (TND) is a Chinese decoction approved and used in Jiangsu Province Hospital for the treatment of ischemic stroke. It shows conclusive efficiency in the improvement of neurologic impairment and activities of daily living of the patients.

AIM OF THE STUDY

Recently, angiogenesis has been recognized as a potential therapeutic strategy for treating cerebral ischemia. This study was aimed to provide comprehensive evidence for the pro-angiogenic effect of TND and characterize the underlying mechanism.

MATERIALS AND METHODS

We firstly established the chemical fingerprinting of TND. Then, the in vitro pro-angiogenic activities of TND were tested on human umbilical vein endothelial cells (HUVECs) through cell viability, wound healing and tube formation assays. The in vivo pro-angiogenic effects were evaluated on transgenic zebrafish embryos [Tg (fli-1: EGFP)] through the formation of intersegmental vessels (ISVs), subintestinal vessels (SIVs) and central arteries (CtAs). Lastly, the potential mechanisms of TND were analyzed by a blocking assay with eight pathways-specific kinase inhibitors.

RESULTS

TND promoted the proliferation, migration and tube formation of HUVECs. TND also rescued the impairment of ISVs, SIVs and CtAs caused by VRI in a dose-dependent manner in zebrafish embryos. TND could activate vascular endothelial growth factor receptor-2 (VEGFR-2), phosphoinositide 3-kinase (PI3K) - protein kinase B (Akt) and Raf - mitogen-activated protein kinase1/2 (MEK1/2) - extracellular regulated kinase 1/2 (ERK1/2) signaling pathways.

CONCLUSION

Our study firstly demonstrated the pro-angiogenic activities of TND. Our work provided evidences for the clinical usage of TND in restoring neurovascular function through promoting angiogenesis in the ischemic cerebral microvascular.

Clavukoellians G-K, New Nardosinane and Aristolane Sesquiterpenoids with Angiogenesis Promoting Activity from the Marine Soft Coral Lemnalia sp

The chemical examination of the marine soft coral Lemnalia sp., collected at the Xisha islands in the South China Sea, resulted in the isolation of four new nardosinane-type sesquiterpenoids, namely clavukoellians G-J (1-4), and one new aristolane sesquiterpene, namely clavukoellian K (5), together with five known compounds, 6-10. The structure elucidation of the isolated natural products was based on various spectroscopic techniques including HRESIMS and NMR, while their absolute configurations were resolved on the basis of comparisons of the ECD spectra with the calculated ECD data. The isolated new compounds 1-5 were evaluated for their anti- and pro- angiogenesis activities in a transgenic fluorescent zebrafish (Tg(vegfr2:GFP)) model. Quantitative analysis revealed that compound 5 displayed pro-angiogenesis activity in a PTK787-induced vascular injury zebrafish model at 2.5 μM. Data showed that compound 5 significantly promoted the angiogenesis in a dose-dependent manner.

Pro-angiogenesis effect and transcriptome profile of Shuxinyin formula in zebrafish

BACKGROUND

Angiogenesis plays a critical role in ischemia disease like coronary heart disease. Shunxinyin formula has been developed for treating coronary heart disease according to the principle of traditional Chinese medicine while its underlying mechanism is not fully elucidated.

PURPOSE

Here, we hypothesize Shuxinyin formula could promote angiogenesis and microcirculation, and the underlying mechanism is also investigated.

METHODS

We established the chemical profile of Shuxinyin (SXY) extract utilizing a UHPLC-Q/Exactive analysis system and evaluated its pro-angiogenesis effect in zebrafish model. The underlying mechanisms were investigated by combination of pharmacological experiments with transcriptome analysis in zebrafish. Zebrafish treated with VEGF was served as the positive control in present study.

RESULTS

We found SXY significantly enhanced the sub-intestinal vessel plexus (SIVs) growth in zebrafish. Co-treatment and post-treatment SXY attenuated VEGF receptor tyrosine kinase inhibitor II (VRI)-induced deficiency of intersegmental vessels (ISVs) in a concentration dependent manner. Post-treatment VEGF, which is a well-known angiogenesis driver, also partially ameliorated VRI-induced ISVs deficiency. In addition, SXY inhibited the down-regulation of VEGF receptors, including kdr, flt1 and kdrl, induced by VRI in zebrafish. The pro-angiogenesis effect of SXY on VRI-induced ISVs deficiency was suppressed by PI3K and JNK inhibitors, and Akt inhibitor abolished the pro-angiogenesis effect of SXY. The transcriptome profile of SXY preventing from VRI-induced vascular growth deficiency revealed that the underlying mechanisms were also co-related to cell junction, apoptosis and autophagy.

CONCLUSION

We could conclude that SXY presented pro-angiogenesis effect and the action mechanisms were involved in VEGF/PI3K/Akt/MAPK signaling pathways, cell junction, apoptosis and autophagy.

Study of pro-angiogenic activity of astilbin on human umbilical vein endothelial cells in vitro and zebrafish in vivo

Astilbin is a dihydroflavonol natural product isolated from a variety of food and medicinal herbs (e.g. Smilax glabra Roxb.), and its mechanism of action in vascular pharmacology remains unclear. The aim of this study was to investigate the pro-angiogenic effects of astilbin and its putative mechanism of action. Briefly, our in vitro studies showed a dose-dependent ability of astilbin to increase the ability of HUVECs to proliferate and migrate, and undergo cell invasion and tube formation. Moreover, astilbin significantly increased the expression levels of several major proteins involved in the angiogenesis pathway, e.g. PI3K, Akt, p38 and ERK1/2. Our in vivo studies demonstrated the ability of astilbin to significantly restore the blood vessel loss induced by VRI in a VRI-induced vascular insufficiency zebrafish model. In conclusion, in this study we first demonstrate that astilbin exhibits pro-angiogenic activity in HUVECs and VRI-induced vascular insufficient zebrafish, possibly through the activation of the PI3K/Akt and MAPK/ERK dependent signaling pathways. These findings suggest that astilbin could be further developed as a potential agent in the prevention or treatment of insufficient angiogenesis related diseases in the future.

Pro-angiogenic activity of astilbin on endothelial cells in vitro and zebrafish in vivo.

Prior anti-CAFs break down the CAFs barrier and improve accumulation of docetaxel micelles in tumor

BACKGROUND

Abnormal expression of stromal cells and extracellular matrix in tumor stroma creates a tight barrier, leading to insufficient extravasation and penetration of therapeutic agents. Cancer-associated fibroblasts (CAFs) take on pivotal roles encouraging tumor progression.

METHOD

To surmount the refractoriness of stroma, we constructed a multi-targeting combined scenario of anti-CAFs agent tranilast and antitumor agent docetaxel micelles (DTX-Ms). Tranilast cut down crosstalk between tumor cells and stromal cells, ameliorated the tumor microenvironment, and enhanced the antiproliferation efficacy of DTX-Ms on cancer cells.

RESULTS

Diverse experiments demonstrated that tranilast enhanced DTX-Ms' antitumor effect in a two-stage pattern by CAFs ablation, tumor cell migration blocking, and metastasis inhibition. Along with activated CAFs decreasing in vivo, the two-stage therapy succeeded in reducing interstitial fluid pressure, normalizing microvessels, improving micelles penetration and retention, and inhibiting tumor growth and metastasis. Interestingly, tranilast alone failed to inhibit tumor growth in vivo, and it could only be used as an adjuvant medicine together with an antitumor agent.

CONCLUSION

Our proposed two-stage therapy offers a promising strategy to enhance antitumor effects by breaking down CAFs barrier and increasing micellar delivery efficiency.

Anti-thrombotic and pro-angiogenic effects of Rubia cordifolia extract in zebrafish

ETHNOPHARMACOLOGICAL RELEVANCE

Rubia cordifolia is a common traditional Chinese medicine that promotes blood circulation and eliminates blood stasis, and has been used to cure diseases related to blood stasis syndrome (BSS) clinically for many years. It has been previously demonstrated that anti-thrombosis and pro-angiogenesis can improve BSS. However, the anti-thrombotic and pro-angiogenic activities of Rubia cordifolia have not been well investigated.

AIM OF STUDY

To determine the potential anti-thrombotic and pro-angiogenic activities of Rubia cordifolia and to elucidate the underlying mechanisms. In addition, the major chemical constituents of Rubia cordifolia extract (QC) were qualitatively analysed by UPLC-Q-TOF/MS to explore the association between pharmacological activity and chemical constituents.

MATERIAL AND METHODS

The QC samples were composed of a 95% ethanol extract and an aqueous extract following extraction using 95% ethanol. UPLC-Q-TOF/MS was used to analyse the major chemical constituents of QC. For the anti-thrombotic experiment of QC, a phenylhydrazine (PHZ)-induced AB strain zebrafish thrombosis model was used. The zebrafish larvae were stained using O-dianisidine, and the heart and caudal vein of the zebrafish were observed and imaged with a fluorescence microscope. The staining intensity of erythrocytes in the heart (SI) of each group and the morphology of thrombus in the caudal vein were used to assess the anti-thrombotic effect of QC. For the pro-angiogenic assay of QC, the intersegmental blood vessel (ISV) insufficiency model of Tg(fli-1: EGFP)y1 transgenic zebrafish (Flik zebrafish), which was induced by the VEGF receptor tyrosine kinase inhibitor II (VRI), was used. The morphology of the intact ISVs and defective ISVs was observed to evaluate the pro-angiogenic activity of QC. The mechanism involved in promoting angiogenesis was studied with real-time PCR.

RESULTS

A total of 12 components in QC were identified based on standard compounds and references, including nine anthraquinones and three naphthoquinones. After treatment with QC, the PHZ-induced thrombosis in AB strain zebrafish larvae decreased to a certain degree, which we believe was related to its dosages, and the therapeutic effect within the 50-200 µg/mL QC treatment groups was especially prominent (P < 0.01, P < 0.001) compared to that in the PHZ model group. Similarly, QC also recovered the loss of the ISVs, which was induced by VRI in Flik zebrafish larvae, which have a certain dose-effect relationship. The pro-angiogenic activity of QC was also conspicuous (P < 0.01, P < 0.001) compared to that of the VRI model group. The following real-time PCR assay proved that QC significantly restored the VRI-induced downregulation of vWF, VEGF-A, kdrl, and flt-1 in Flik zebrafish (P < 0.05, P < 0.01, P < 0.001).

CONCLUSIONS

A total of 12 compounds from QC were analysed by UPLC-Q-TOF/MS. The data of the pharmacological experiments demonstrated that QC presented anti-thrombotic and pro-angiogenic activities in zebrafish, and the principal active components were likely anthraquinones and naphthoquinones. Thus, the current study provided a theoretical basis for the clinical use of Rubia cordifolia as a traditional Chinese medicine in promoting blood circulation and eliminating stasis.

Pro-angiogenic effects of Ilexsaponin A1 on human umbilical vein endothelial cells in vitro and zebrafish in vivo

BACKGROUND

Ilexsaponin A1 is the major bioactive ingredient of Ilex pubescens Hook. et Arn. This plant has been conventionally used in Traditional Chinese Medicine for the treatment of cardiovascular diseases including stroke, coronary arterial disease, and peripheral vascular diseases.

PURPOSE

To investigate the pro-angiogenic effect of Ilexsaponin A1 and its mechanism of action.

STUDY DESIGN

Human umbilical vein endothelial cells (HUVECs) and transgenic zebrafish Tg(fli1:EGFP) were employed as an in vitro and in vivo model respectively.

METHODS

Pro-angiogenic effects of Ilexsaponin A1 were examined by assessing endothelial cell proliferation, migration, invasion and tube formation. The mechanism of pro-angiogenic effects was investigated by measuring the expression level of various signalling proteins. Furthermore, vascular endothelial growth factor (VEGF) tyrosine kinase inhibitor II (VRI)-induced vascular insufficient transgenic zebrafish model was used to confirm the results of the HUVECs results in vivo.

RESULTS

Ilexsaponin A1 significantly promoted cell proliferation, migration, invasion and tube formation in HUVECs, and rescued blood vessel loss in VRI-induced vascular insufficient zebrafish. Ilexsaponin A1 upregulated p-Akt, p-mTOR, p-Src, p-FAK, p-MEK, and p-Erk1/2 in HUVECs.

CONCLUSION

This study showed that Ilexsaponin A1 exhibits pro-angiogenic activity in HUVECs and VRI-induced vascular insufficient zebrafish, probably by activating Akt/mTOR, MAPK/ERK and Src- and FAK-dependent signalling pathways. The findings suggest that Ilexsaponin A1 and probably I. pubescens, a major source of Ilexsaponin A1, could be developed as a potential therapeutic agent for preventing or treating cardiovascular diseases and/or other diseases related to vascular insufficiency.

Tcf7l2 plays pleiotropic roles in the control of glucose homeostasis, pancreas morphology, vascularization and regeneration

Type 2 diabetes (T2D) is a disease characterized by impaired insulin secretion. The Wnt signaling transcription factor Tcf7l2 is to date the T2D-associated gene with the largest effect on disease susceptibility. However, the mechanisms by which TCF7L2 variants affect insulin release from β-cells are not yet fully understood. By taking advantage of a tcf7l2 zebrafish mutant line, we first show that these animals are characterized by hyperglycemia and impaired islet development. Moreover, we demonstrate that the zebrafish tcf7l2 gene is highly expressed in the exocrine pancreas, suggesting potential bystander effects on β-cell growth, differentiation and regeneration. Finally, we describe a peculiar vascular phenotype in tcf7l2 mutant larvae, characterized by significant reduction in the average number and diameter of pancreatic islet capillaries. Overall, the zebrafish Tcf7l2 mutant, characterized by hyperglycemia, pancreatic and vascular defects, and reduced regeneration proves to be a suitable model to study the mechanism of action and the pleiotropic effects of Tcf7l2, the most relevant T2D GWAS hit in human populations.

Dalbergia odorifera extract promotes angiogenesis through upregulation of VEGFRs and PI3K/MAPK signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

The heart wood of Dalbergia odorifera is a Chinese herbal medicine commonly used for the treatment of various ischemic diseases in Chinese medicine practice.

AIM OF THE STUDY

In this study, therapeutic angiogenesis effects of the Dalbergia odorifera extract (DOE) were investigated on transgenic zebrafish in vivo and human umbilical vein endothelial cells (HUVECs) in vitro.

MATERIALS AND METHODS

The pro-angiogenic effects of DOE on zebrafish were examined by subintestinal vessels (SIVs) sprouting assay and intersegmental vessels (ISVs) injury assay. And the pro-angiogenic effects of DOE on HUVECs were examined by MTT, scratch assay, protein chip and western blot.

RESULTS

In the in vivo studies, we found that DOE was able to dose-dependently promote angiogenesis in zebrafish SIVs area. In addition, DOE could also restore the injury in zebrafish ISVs area and upregulate the reduced mRNA expression of VEGFRs including kdr, kdrl and flt-1 induced by VEGF receptor kinase inhibitor II (VRI). In the in vitro studies, we observed that DOE promoted the proliferation, migration of HUVECs and also restored the injury induced by VRI. Moreover, protein chip and western blot experiments showed the PI3K/MAPK cell proliferation/migration pathway were activated by DOE.

CONCLUSIONS

DOE has a therapeutic effects on angiogenesis, and its mechanism may be related to adjusting the VEGFRs mRNA and activation of PI3K/MAPK signaling pathway. These results suggest a strong potential for Dalbergia odorifera to be developed as an angiogenesis-promoting therapeutic.

Spatholobi Caulis extracts promote angiogenesis in HUVECs in vitro and in zebrafish embryos in vivo via up-regulation of VEGFRs

ETHNOPHARMACOLOGICAL RELEVANCE

Spatholobi Caulis is a traditional blood-activating and stasis-dispelling herb medicine, which has been used to treat diseases related to blood stasis syndrome (BSS) by inhibiting platelet aggregation, stimulate hematopoiesis, etc. It has been demonstrated that pro-angiogenesis could improve BSS. However, the pro-angiogenic activity of Spatholobi Caulis was not well elucidated AIM OF STUDY: To determine the potential pro-angiogenic activity of Spatholobi Caulis and elucidate its underlying mechanism. The active fractions of Spatholobi Caulis were further screened.

MATERIAL AND METHODS

Gelatin precipitation and reversed-phase liquid chromatography (RPLC) were used to purify the methanol extracts of Spatholobi Caulis, respectively. The RPLC was also used to prepare fractions. Total flavonoids of purified methanol extracts of Spatholobi Caulis (PSC) were determined using ultraviolet spectrophotometry. The morphological observation of subintestinal vessel plexus (SIVs) and tyrosine kinase inhibitor II (VRI)-induced intersegmental blood vessels (ISVs) loss in transgenic zebrafish Tg(fli-1a: EGFP)y1 were selected to evaluate the pro-angiogenic activity of PSC in vivo. Cell proliferation by MTT assay and cell migration assay were used to evaluate the pro-angiogenesis effect of PSC in human umbilical vein endothelial cells (HUVECs) in vitro. Both zebrafish and HUVECs were used in screening active fractions of PSC. The mechanism of PSC promoting angiogenesis were studied by real-time PCR in zebrafish and western blotting in HUVECs.

RESULTS

Co-treatment PSC dramatically rescued VRI-induced ISVs loss in zebrafish embryos in a dose-dependent manner and 80% of the defective vascular recovered at the concentration of 30μg/ml compared with VRI-only group. PSC also concentration-dependently increased average sprouting number and diameter of SIVs in zebrafish embryo. Real-time PCR assay proved that PSC significantly restored the down regulation of VEGFRs including Flt-1, Kdr and Kdrl induced by VRI in zebrafish (P<0.001). Furthermore, PSC not only promoted proliferation and migration of normal HUVECs but also ameliorated VRI-induced HUVECs cytotoxicity. Western blotting assay showed that co-treatment of PSC increased the expression of VEGFRs and phosphorylation of MAPKs which decreased by VRI treatment. In addition, quality evaluation experiments showed that the content of total flavonoids of PSC reached 56.36% and the main pro-angiogenic fractions of PSC were F3, F4 and F5 both in zebrafish and HUVECs.

CONCLUSIONS

Our data demonstrated that PSC presented pro-angiogenic activity both in zebrafish and HUVECs, and principal pro-angiogenic active components were likely flavonoids. Thus, the current study provided evidence for the clinical usage of Spatholobi Caulis in promoting blood circulation and removing stasis in traditional Chinese medicine (TCM).

Lanthanide Hydroxide Nanoparticles Induce Angiogenesis via ROS-Sensitive Signaling

Recent studies suggest that the nanorods consisting of europium hydroxide could promote angiogenesis. In this study, it is sought to determine if additional types of nanoparticles are capable of enhancing angiogenesis and in addition, understand the underlying mechanisms. For this reason, a method is employed that combines a high throughput in vitro cell based screen coupled with an in vivo validation using vascular specific green fluorescent protein reporter transgenic zebrafish for examining proangiogenesis activity. After screening multiple types of nanoparticles, it is discovered that four of them, Eu(III) (OH)3 rods (Eu rods), Eu(III) (OH)3 spheres (Eu spheres), Tb(III) (OH)3 rods (Tb rods), and Tb(III) (OH)3 spheres (Tb spheres), are the most effective in promoting angiogenesis. It is also showed that ionic forms of europium nitrate [Eu(NO3 )3 ] (Eu) and terbium nitrate [Tb(NO3 )3 ] (Tb), the two lanthanide elements for these four nanoparticles, are also capable of enhancing angiogenesis. However, this effect is further enhanced by nanoparticle synthesis. Finally, it is demonstrated that reactive oxygen species H2 O2 is a key factor in the process of proangiogenesis by lanthanide elemental nanoparticles.

Formononetin promotes angiogenesis through the estrogen receptor alpha-enhanced ROCK pathway

Formononetin is an isoflavone that has been shown to display estrogenic properties and induce angiogenesis activities. However, the interrelationship between the estrogenic properties and angiogenesis activities of formononetin are not well defined. In the present study, docking and enzymatic assay demonstrated that formononetin displayed direct binding to the ligand-binding domain (LBD) of estrogen receptor alpha (ERα) with an agonistic property. Results from Human Umbilical Vein Endothelial Cells (HUVEC) by using real-time migration xCELLigence system, immunofluorescence and western blotting provided strong evidences of formononetin induced endothelial cell migration and dramatic actin cytoskeleton spatial modification through ERα-enhanced-ROCK-II/MMP2/9 signaling pathways. In addition, results from co-immunoprecipitation suggested formononetin induced cell migration via recruiting of ERα/ROCK-II activated complex formation. More interestingly, in zebrafish embryo we observed that formononetin significantly promoted angiogenic sproutings in the subintestinal vessels (SIVs) that could be completely abolished by ROCK inhibitor. In this study, we elucidated the underlying mechanisms that formononetin produced proangiogenesis effects through an ERα-enhanced ROCK-II signaling pathways. Results from the present study also expand our knowledge about the enigmatic underlying mechanisms of phytoestrogenic compounds in the promotion of angiogenesis in relation to ERα and ROCK interaction in endothelial cells and their relationship with actin assembly and cell migration.

Zebrafish models of cardiovascular diseases and their applications in herbal medicine research

The zebrafish (Danio rerio) has recently become a powerful animal model for cardiovascular research and drug discovery due to its ease of maintenance, genetic manipulability and ability for high-throughput screening. Recent advances in imaging techniques and generation of transgenic zebrafish have greatly facilitated in vivo analysis of cellular events of cardiovascular development and pathogenesis. More importantly, recent studies have demonstrated the functional similarity of drug metabolism systems between zebrafish and humans, highlighting the clinical relevance of employing zebrafish in identifying lead compounds in Chinese herbal medicine with potential beneficial cardiovascular effects. This paper seeks to summarise the scope of zebrafish models employed in cardiovascular studies and the application of these research models in Chinese herbal medicine to date.

The promise of zebrafish as a chemical screening tool in cancer therapy

Cancer progression in zebrafish recapitulates many aspects of human cancer and as a result, zebrafish have been gaining popularity for their potential use in basic and translational cancer research. Human cancer can be modeled in zebrafish by induction using chemical mutagens, xenotransplantation or by genetic manipulation. Chemical screens based on zebrafish cancer models offer a rapid, powerful and inexpensive means of evaluating the potential of suppression or prevention on cancer. The identification of small molecules through such screens will serve as ideal entry points for novel chemical therapies for cancer treatment. This article outlines advances that have been made within the growing field of zebrafish cancer models and presents their advantages for chemical drug screening.