Dihydroartemisinin up-regulates VE-cadherin expression in human renal glomerular endothelial cells

Artemisinin suppressed tumour growth and induced vascular normalisation in oral squamous cell carcinoma via inhibition of macrophage migration inhibitory factor

BACKGROUND

Tumour vascular normalisation therapy advocates a balance between pro-angiogenic factors and anti-angiogenic factors in tumours. Artemisinin (ART), which is derived from traditional Chinese medicine, has been shown to inhibit tumour growth; however, the relationship between ART and tumour vascular normalisation in oral squamous cell carcinoma (OSCC) has not been previously reported.

METHODS

Different concentrations(0 mg/kg, 25 mg/kg, 50 mg/kg, 100 mg/kg)of ART were used to treat the xenograft nude mice model of OSCC. The effects of ART on migration and proliferation of OSCC and human umbilical vein endothelial cells (HUVEC) cells were detected by scratch assay and CCK-8 assay. OSCC cells with macrophage migration inhibitory factor (MIF) silenced were constructed to explore the effect of MIF.

RESULTS

Treatment with ART inhibited the growth and angiogenesis of OSCC xenografts in nude mice and downregulated vascular endothelial growth factor (VEGF), IL-8, and MIF expression levels. ART reduced the proliferation, migration, and tube formation of HUVEC, as well as the expression of VEGFR1 and VEGFR2. When the dose of ART was 50 mg/kg, vascular normalisation of OSCC xenografts was induced. Moreover, VEGF and IL-8 were needed in rhMIF restoring tumour growth and inhibit vascular normalisation after the addition of rhMIF to ART-treated cells.

CONCLUSION

Artemisinin might induce vascular normalisation and inhibit tumour growth in OSCC through the MIF-signalling pathway.

Sertaconazole nitrate targets IDO1 and regulates the MAPK signaling pathway to induce autophagy and apoptosis in CRC cells

Colorectal cancer (CRC) has become the third most frequently occurring malignant tumor worldwide. It is vital to identify novel, effective targeted treatments while considering side effects and drug resistance in the clinic. Recently, the tryptophan-metabolizing enzyme indole-2, 3-dioxygenase 1 (IDO1) has been widely reported to be overexpressed in CRC, indicating that blocking IDO1 with small-molecule inhibitors may be a promising approach to CRC treatment. In this study, the antifungal drug sertaconazole nitrate (STZ) was repurposed and showed antitumor activity, and therefore, its anticancer effect was further investigated in CRC cells. The SwissTargetPrediction analysis indicated that STZ binding to IDO1 was significantly and highly probable, and STZ was found to downregulate IDO1 in CRC cells in a dose-dependent manner. STZ exhibited considerable antiproliferative activity and induced apoptosis and autophagy in HCT116 and RKO cells. Moreover, based on an RNA-seq analysis, STZ was shown to regulate signal transducer and activator of transcription 3 (STAT3) and the mitogen-activated protein kinase (MAPK) signaling pathways. We discovered that STZ suppressed tumor growth in an HCT116 nude mouse xenograft tumor model without causing evident cytotoxicity. In conclusion, our results reveal that STZ induces antitumor effects in CRC by inhibiting IDO1-modulated autophagy and apoptosis, providing a clue for repurposing STZ as a novel and potentially effective candidate medication for the future treatment of CRC.

Low-Dose X-Ray Increases Paracellular Permeability of Human Renal Glomerular Endothelial Cells

Objective

Glomerular endothelium functions as a filtration barrier of metabolites in the kidney. Although X-ray irradiation modulated the permeability of the vascular endothelium, the response of human renal glomerular endothelial cells (HRGECs) to low-dose X-ray irradiation has not been investigated. We evaluated the impacts of low-dose X-ray irradiation on HRGECs and revealed the underlying mechanism.

Methods

HRGECs were exposed to X-ray with doses of 0, 0.1, 0.5, 1.0, and 2.0 Gy. The proliferation, viability, and apoptosis of HRGECs were examined by MTT assay, trypan blue staining assay, and TUNEL staining, respectively. The paracellular permeability was assessed by paracellular permeability assay. The expression of VE-cadherin was investigated via immunofluorescence assay. Western blot and qRT-PCR detected the expression levels of VE-cadherin and CLDN5. Besides, the expression levels of pVE-cadherin (pY658), TGF-β, TGF-βRI, Src, p-Src, Smad2, p-Smad2, Smad3, p-Smad3, SNAIL, SLUG, and apoptosis-related proteins were tested by Western blot.

Results

The proliferation, viability, and apoptosis of HRGECs were not affected by low-dose (<2.0 Gy) X-ray irradiation. X-ray irradiation dose-dependently reduced the level of VE-cadherin, and VE-cadherin and CLDN5 levels were reduced with X-ray irradiation. The levels of pY658, p-Src, p-Smad2, and p-Smad3 were upregulated with the increase in X-ray dose. Besides, the paracellular permeability of HRGECs was increased by even low-dose (<2.0 Gy) X-ray irradiation. Therefore, low-dose X-ray irradiation reduced the cumulative content of VE-cadherin and increased the level of pY658 via activation of the TGF-β signaling pathway.

Conclusion

Even though low-dose X-ray exposure had no impact on proliferation, viability, and apoptosis of HRGECs, it increased the paracellular permeability by deterioration and downregulation of VE-cadherin through stimulating the TGF-β signaling pathway. This study built the framework for kidney response to low-dose irradiation exposure.

Tongxinluo prevents chronic obstructive pulmonary disease complicated with atherosclerosis by inhibiting ferroptosis and protecting against pulmonary microvascular barrier dysfunction

Cardiovascular comorbidities are pervasive in chronic obstructive pulmonary disease (COPD) and often result in serious adverse cardiovascular events. Tongxinluo (TXL) has been clinically verified to treat atherosclerosis (AS), improve lung function and alleviate dyspnoea. The present study aimed to explore the effect of lung microvascular barrier dysfunction on AS in COPD and the potential pulmonary protective mechanisms of TXL in COPD complicated with AS. COPD complicated with AS was induced in mice by cigarette smoke (CS) exposure and high-fat diet (HFD) feeding. The mice were treated with atorvastatin (ATO), TXL or combination therapy (ATO+TXL) for 20 weeks. Pulmonary function, lung pathology, serum lipid levels, atherosclerotic plaque area and indicators of barrier function, oxidative stress and ferroptosis in lung tissue were evaluated. In vitro, human pulmonary microvascular endothelial cells (HPMECs) were pretreated with TXL for 4 h and then incubated with cigarette smoke extract (CSE) and homocysteine (Hcy) for 36 h to induce barrier dysfunction. Then the indicators of barrier function, oxidative stress and ferroptosis were measured. The results demonstrate that CS aggravated dyslipidaemia, atherosclerotic plaque formation, pulmonary function decline, pathological injury, barrier dysfunction, oxidative stress and ferroptosis in the HFD-fed mice. However, these abnormalities were partially reversed by ATO and TXL. Similar results were observed in vitro. In conclusion, pulmonary microvascular barrier dysfunction plays an important role by which COPD affects the progression of AS, and ferroptosis may be involved. Moreover, TXL delays the progression of AS and reduces cardiovascular events by protecting the pulmonary microvascular barrier and inhibiting ferroptosis.

Retardant effect of dihydroartemisinin on ulcerative colitis in a JAK2/STAT3-dependent manner

Dihydroartemisinin (DHA) is a semi-synthetic derivative and the main active metabolite of artemisinin. The purpose of this study was to investigate the effect of DHA on the ulcerative colitis (UC) in both in vivo and in vitro models. Weight, survival rate, colon length, and Disease Activity Index score were used to evaluate the severity of colitis. Reverse transcription quantitative polymerase chain reaction and enzyme-linked immunosorbent assay were used to detect the expressions of cytokines interleukin (IL)-1, IL-1β, IL-4, IL-6, IL-10, IL-12, and tumor necrosis factor-α (TNF-α). The expressions of Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3), and the phosphorylation of JAK2 (p-JAK2) and STAT3 (p-STAT3), were measured by western blot analysis. Western blot analysis and immunohistochemistry were used to detect the expressions of tight junction proteins. We found that the weights and colon lengths of mice in dextran sodium sulfate (DSS)+DHA group were significantly lower and longer than those in the DSS group, respectively. Compared with those in the DSS group, the expressions of IL-1β, IL-6, IL-17, and TNF-α in the DSS+DHA and DSS+5-aminosalicylic acid (5-ASA) groups were decreased, while the expressions of IL-4 and IL-10 were significantly upregulated. DHA largely increased the expressions of zonula occludens-1 and occludin. Western blot analysis and/or immunohistochemical staining analysis showed that the expressions of JAK2, STAT3, p-JAK2, and p-STAT3 in DSS+DHA and DSS+5-ASA groups were significantly lower than those in DSS group. DHA has a specific therapeutic effect on UC. The anti-inflammatory mechanism of DHA is related to the blockage of the JAK2/STAT3 signaling pathway. These findings provide evidence that DHA may be a useful drug and is expected to become a promising new treatment for human UC.

Recent pharmacological advances in the repurposing of artemisinin drugs

Artemisinins are a family of sesquiterpene lactones originally derived from the sweet wormwood (Artemisia annua). Beyond their well-characterized role as frontline antimalarial drugs, artemisinins have also received increased attention for other potential pharmaceutical effects, which include antiviral, antiparsitic, antifungal, anti-inflammatory, and anticancer activities. With concerted efforts in further preclinical and clinical studies, artemisinin-based drugs have the potential to be viable treatments for a great variety of human diseases. Here, we provide a comprehensive update on recent reports of pharmacological actions and applications of artemisinins outside of their better-known antimalarial role and highlight their potential therapeutic viability for various diseases.

Dihydroartemisinin alleviates skin fibrosis and endothelial dysfunction in bleomycin-induced skin fibrosis models

OBJECTIVE

The present study was to investigate whether dihydroartemisinin (DHA), which is a highly effective and safe drug in the treatment of malaria, could be repurposed for the treatment of skin fibrosis and vascular dysfunction in systemic sclerosis (SSc).

METHODS

The value of DHA was determined using a bleomycin-induced model of skin fibrosis. mRNA transcriptome analysis was performed, and the targets of DHA on fibroblasts were identified. Immunofluorescence staining was used to identify dermal vessels undergoing endothelial-to-mesenchymal transition (EndoMT). Autophagic flux was detected by western blot and mRFP-GFP-LC3 adenovirus vector transfection.

RESULTS

Both systemic and topical administration of DHA decreased dermal thickness and collagen deposition and alleviated EndoMT in bleomycin-induced skin fibrosis mice model. Treatment of human umbilical vein endothelial cells (HUVECs) with TGF-β1 resulted in the acquisition of the activation marker (α-SMA) and loss of endothelial markers (CD31 and VE-cadherin), a process that was restored by DHA. DHA significantly suppressed skin fibroblast activation and collagen-1 production mainly through regulating PI3K-Akt pathway. DHA also induced fibroblast autophagic flux and that autophagy dependently suppressed collagen-1 production.

CONCLUSION

The results of the present study revealed that oral and topical DHA administration ameliorated tissue fibrosis and protected dermal blood vessels from bleomycin-induced EndoMT. Our study has elucidated the value of repurposing DHA for the treatment of SSc. Key Points • Oral or topical usage of DHA alleviated dermal fibrosis and EndoMT in bleomycin-induced skin fibrosis mice models. • DHA autophagy dependently inhibited fibroblast activation and collagen deposition via PI3K-ATK pathway. • DHA inhibited EndoMT of HUVECs induced by TGF-β1 by the downregulation of α-SMA and the upregulation of CD31 and VE-cadherin.

Dihydroartemisinin inhibits the expression of von Willebrand factor by downregulation of transcription factor ERG in endothelial cells

Dihydroartemisinin (DHA), a semi‐synthetic derivative of artemisinin, has effective antitumor and anti‐inflammatory actions. von Willebrand factor (vWF), a large multifunctional glycoprotein, has a prominent function in hemostasis and is a key factor in thrombus formation. In addition, vWF has been regarded as a prospective biomarker for the diagnosis of endothelial dysfunction. In our experiment, we observed that 25 μM DHA specifically downregulated the expression of vWF mRNA and protein in human umbilical vein endothelial cells (HUVECs). Further investigations demonstrated that this DHA‐decreased vWF expression was mediated by the transcription factor ERG and not GATA3. Luciferase activity assay confirmed that DHA regulated the ERG binding with the −56 ETS‐binding motif on the human vWF promoter. Thus, the −56 ETS motif on the vWF promoter region regulates the expression of vWF gene which is induced by DHA. Taken together, we proved that DHA decreased the vWF transcription through the downregulation of ERG in HUVECs. As vWF plays a key role in vascular homeostasis, our findings suggest a new role of DHA in vascular diseases.

Manganese exposure induces permeability in renal glomerular endothelial cells via the Smad2/3-Snail-VE-cadherin axis

Manganese (Mn) is an essential micronutrient. However, it is well established that Mn overexposure causes nervous system diseases. In contrast, there are few reports on the effects of Mn exposure on glomerular endothelium. In the present study, the potential effects of Mn exposure on glomerular endothelium were evaluated. Sprague Dawley rats were used as a model of Mn overexposure by intraperitoneal injection of MnCl₂·H₂O at 25 mg/kg body weight. Mn exposure decreased expression of vascular endothelial-cadherin, a key component of adherens junctions, and increased exudate from glomeruli in Sprague Dawley rats. Human renal glomerular endothelial cells were cultured with different concentration of Mn. Exposure to 0.2 mM Mn increased permeability of human renal glomerular endothelial cell monolayers and decreased vascular endothelial-cadherin expression without inducing cytotoxicity. In addition, Mn exposure increased phosphorylation of mothers against decapentaplegic homolog 2/3 and upregulated expression of zinc finger protein SNAI1, a negative transcriptional regulator of vascular endothelial-cadherin. Our data suggest Mn exposure may contribute to development of glomerular diseases by inducing permeability of glomerular endothelium.

The Therapeutic Effect of Artemisinin and Its Derivatives in Kidney Disease

Artemisinin (ARS) and its derivatives (ARSs) are recommended as the first-line antimalarial drugs for the treatment of malaria. Besides antimalarial function, its potent anti-inflammatory and immunoregulatory properties, as well as the ability to regulate oxidative stress have brought them to a prominent position. As researchers around the world are continually exploring the unknown biological activities of ARS derivatives, experimental studies have shown much progress in renal therapy. This review aims to give a brief overview of the current research on ARSs applications for kidney treatment with the evaluation of therapeutic properties and potential molecular mechanisms.

Dihydroartemisinin inhibits the proliferation of IgAN mesangial cells through the mTOR signaling pathway

IgA nephropathy (IgAN) is an autoimmune kidney disease and is the most prevalent form of glomerular kidney disease in China and worldwide. IgA immune complex deposition accompanied by mesangial cell proliferation and mesangial matrix expansion is the most basic pathological feature of IgAN. Dihydroartemisinin (DHA), an antimalarial drug, was recently reported to be effective in treating autoimmune diseases. However, its potential therapeutic role in IgAN is relatively unstudied. The aim of this study was to investigate the pharmacological effects and the underlying mechanisms of DHA in the treatment of IgAN. In this study, renal biopsy specimens were collected for immunohistochemistry. In vitro, 25 μg/ml concentrations of aggregated IgA1 (aIgA1) was used to construct the IgAN mesangial cell model. Stimulated human mesangial cells (HMCs) were treated for 24 h with DHA (0-15 μM) and were collected for western blot analyses. Cell proliferation was assessed by Cell Counting Kit 8 (CCK8) and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. In vitro, our results showed that DHA could downregulate the mammalian target of rapamycin/ribosomal protein S6 kinase beta-1 (mTOR/S6K1) signaling pathway, promote cell autophagy, and ameliorate cell proliferation in aIgA1-induced HMCs. The results suggested that DHA may represent a novel class of mTOR inhibitor and promote an anti-proliferation effect in IgAN HMCs, which provides an alternative approach for IgAN treatment.

Dihydroartemisinin inhibits endothelial cell tube formation by suppression of the STAT3 signaling pathway

AIMS

Endothelial cell (EC) tube formation is crucial for tumor angiogenesis, which becomes a target for chemotherapy. The anti-malaria agent dihydroartemisinin (DHA) inhibited tumor growth and angiogenesis. The aim of this study was to investigate the effects of DHA on EC tube formation and the underlying mechanisms.

MATERIALS AND METHODS

Human umbilical vein endothelial cells (HUVECs) were cultured with different concentrations of DHA, and the tube formation was measured by in vitro angiogenesis assay. The protein levels of signal transducer and activator of transcription factor 3 (STAT3), phosphorylated STAT3 and fatty acid synthase (FASN) were detected by Western blotting. The gene expression of FASN was determined by real time-polymerase chain reaction (RT-PCR). The FASN siRNA and STAT3 (Y705D) vector were introduced into HUVECs by lipofectin transfection.

KEY FINDINGS

DHA treatment inhibited tube formation, and the phosphorylation of STAT3 on Y705 of HUVECs. The expression of FASN was down-regulated by DHA and STAT3 inhibitor. The inhibitory effect of DHA on FASN expression in HUVECs was eliminated by co-treatment with the STAT3 inhibitor. Over-expression of STAT3 (Y705D) relieved the inhibitory effect of DHA on tube-formation and FASN expression. Under hypoxia condition, expression of FASN was up-regulated but inhibited by DHA treatment in HUVECs through suppression of STAT3 phosphorylation.

SIGNIFICANCE

We demonstrate that DHA inhibits the protein level of FASN via attenuation of the Y705 phosphorylation of STAT3, and subsequently inhibits tube formation of HUVECs. Our results support the therapeutic potential of DHA on angiogenesis.

Dihydroartemisinin enhances VEGFR1 expression through up-regulation of ETS-1 transcription factor

Angiogenesis is required for tumor growth. Dihydroartemisinin (DHA), a the effective anti-malarial derivative of artemisinin, demonstrated potent anti-angiogenic activities that closely related to the regulation of vascular endothelial growth factor (VEGF) signaling cascade. VEGF receptor 1 (VEGFR1), a receptor in endothelial cells (ECs), coordinately regulate angiogenic activity triggered by ligand-receptor binding. Here we aimed to explore the effects of DHA on VEGFR1 expression in ECs. We found that DHA significantly increases VEGFR1 expression in human umbilical vein endothelial cells (HUVECs). In addition, DHA significantly upregulates the level of V-Ets Avian Erythroblastosis Virus E26 Oncogene Homolog 1 (ETS-1), a transcriptional factor which binds to the human VEGFR1 promoter. ChIP assay showed that DHA increases ETS-1 binding to the -52 ETS motif on the VEGFR1 promoter. Knockdown of ETS-1 by RNA interference abolished DHA-induced increase of VEGFR1 expression. Taken together, we demonstrated that DHA elevates VEGFR1 expression via up-regulation of ETS-1 transcription in HUVECs.