Dihydroartemisinin ameliorates sepsis-induced hyperpermeability of glomerular endothelium via up-regulation of occludin expression

Endothelial dysfunction: Pathophysiology and therapeutic targets for sepsis-induced multiple organ dysfunction syndrome

Sepsis and septic shock are critical medical conditions characterized by a systemic inflammatory response to infection, significantly contributing to global mortality rates. The progression to multiple organ dysfunction syndrome (MODS) represents the most severe complication of sepsis and markedly increases clinical mortality. Central to the pathophysiology of sepsis, endothelial cells play a crucial role in regulating microcirculation and maintaining barrier integrity across various organs and tissues. Recent studies have underscored the pivotal role of endothelial function in the development of sepsis-induced MODS. This review aims to provide a comprehensive overview of the pathophysiology of sepsis-induced MODS, with a specific focus on endothelial dysfunction. It also compiles compelling evidence regarding potential small molecules that could attenuate sepsis and subsequent multi-organ damage by modulating endothelial function. Thus, this review serves as an essential resource for clinical practitioners involved in the diagnosing, managing, and providing intensive care for sepsis and associated multi-organ injuries, emphasizing the importance of targeting endothelial cells to enhance outcomes of the patients.

Dihydroartemisinin abolishes cisplatin-induced nephrotoxicity in vivo

Dihydroartemisinin (DHA), a derivative of artemisinin which is primarily used to treat malaria in clinic, also confers protective effect on lipopolysaccharide-induced nephrotoxicity. While, the activities of DHA in cisplatin (CDDP)-caused nephrotoxicity are elusive. To investigate the role and underlying mechanism of DHA in CDDP-induced nephrotoxicity. Mice were randomly separated into four groups: normal, CDDP, and DHA (25 and 50 mg/kg were orally injected 1 h before CDDP for consecutive 10 days). All mice except the normal were single injected intraperitoneally with CDDP (22 mg/kg) for once on the 7th day. Combined with quantitative proteomics and bioinformatics analysis, the impact of DHA on renal cell apoptosis, oxidative stress, biochemical indexes, and inflammation in mice were investigated. Moreover, a human hepatocellular carcinoma cells xenograft model was established to elucidate the impact of DHA on tumor-related effects of CDDP. DHA reduced the levels of creatinine (CREA) (p < 0.01) and blood urea nitrogen (BUN) (p < 0.01), reversed CDDP-induced oxidative, inflammatory, and apoptosis indexes (p < 0.01). Mechanistically, DHA attenuated CDDP-induced inflammation by inhibiting nuclear factor κB p65 (NFκB p65) expression, and suppressed CDDP-induced renal cell apoptosis by inhibiting p63-mediated endogenous and exogenous apoptosis pathways. Additionally, DHA alone significantly decreased the tumor weight and did not destroy the antitumor effect of CDDP, and did not impact AST and ALT. In conclusion, DHA prevents CDDP-triggered nephrotoxicity via reducing inflammation, oxidative stress, and apoptosis. The mechanisms refer to inhibiting NFκB p65-regulated inflammation and alleviating p63-mediated mitochondrial endogenous and Fas death receptor exogenous apoptosis pathway.

Tumour necrosis factor α-308 G/a and -238 G/a polymorphisms as predicator of diabetic retinopathy in Egyptians

BACKGROUND

Diabetic retinopathy (DR) is a duration dependent serious micro vascular insult of diabetes mellitus. Inflammation has a critical role in the development of early and late stage of DR. Tumour necrosis factor alpha (TNF-α) is an inflammatory cytokine that promoteup regulation of adhesion molecule expression, leukocyte recruitment and monocyte attraction. TNF-α levels are increased in retinas or vitreous of diabetic animals. A cross-sectional, observational study was performed in a sample of diabetic patients who attend diabetes polyclinic of RIO Hospital, Giza, Egypt, between October 2016 and December 2019. Three hundred diabetic patients were studied (150 males and 150 females). 100 diabetic patients without retinopathy, 100 diabetic patients with proliferative retinopathy (PDR), 100diabetic patients with non-proliferative retinopathy (NPDR), also 100 healthy subjects as a control group All patients and subjects were analysed for serum TNF-α levels by ELISA assay and -308 G/A and -238 G/A polymorphism by using Restriction fragment length polymorphisms.

AIM

Evaluating the role of tumour necrosis factor α and -308 G/A, -238 G/A polymorphisms in the pathogenesis of proliferative diabetic retinopathy among Egyptian patients.

RESULTS

A statistically significant increase in TNF-α levels was detected in diabetic without retinopathy, NPDR and PDR groups compared to control group (p > .001). There were no significant different in Genotype and allele frequencies of the -308G/A, and -238 G/A, polymorphisms in both NPDR and PDR. However, the G/G genotype of the -308 G/A polymorphism occurred more frequently in PDR patients with than NPDR patients (0.74% vs 0.68%).

CONCLUSION

The present study clearly demonstrated increased levels of TNF-α, in diabetic patients with diabetic without retinopathy, NPDR and PDR. Furthermore, this study suggested that TNF-α assay could be used as diagnostic tools to predict the initiation and progression of diabetic retinopathy. They could serve as biomarkers not only for an early detection of the disease, but also to monitor the effects of therapy. Also, the G/G genotype of the -308 G/A polymorphism and the G allele of TNF-α gene were more frequent in PDR patients than with NPDR.

Therapeutic potential of artemisinin and its derivatives in managing kidney diseases

Artemisinin, an antimalarial traditional Chinese herb, is isolated from Artemisia annua. L, and has shown fewer side effects. Several pieces of evidence have demonstrated that artemisinin and its derivatives exhibited therapeutic effects on diseases like malaria, cancer, immune disorders, and inflammatory diseases. Additionally, the antimalarial drugs demonstrated antioxidant and anti-inflammatory activities, regulating the immune system and autophagy and modulating glycolipid metabolism properties, suggesting an alternative for managing kidney disease. This review assessed the pharmacological activities of artemisinin. It summarized the critical outcomes and probable mechanism of artemisinins in treating kidney diseases, including inflammatory, oxidative stress, autophagy, mitochondrial homeostasis, endoplasmic reticulum stress, glycolipid metabolism, insulin resistance, diabetic nephropathy, lupus nephritis, membranous nephropathy, IgA nephropathy, and acute kidney injury, suggesting the therapeutic potential of artemisinin and its derivatives in managing kidney diseases, especially the podocyte-associated kidney diseases.

Dihydroartemisinin protects blood-brain barrier permeability during sepsis by inhibiting the transcription factor SNAI1

Blood–brain barrier (BBB) injury is involved in the pathogenesis of sepsis‐associated encephalopathy. In this study, we used dihydroartemisinin (DHA), a derivative of artemisinin, to treat a cecal ligation and puncture (CLP)‐induced mouse sepsis model and a tumour necrosis factor α (TNF‐α)‐stimulated human cerebral microvessel endothelial cells (hCMEC)/D3 cell line. We found that DHA decreased BBB permeability and increased the expression of the tight junction protein occludin (OCLN) in the CLP model. In hCMEC/D3 cells, DHA decreased TNF‐α‐induced hyperpermeability and increased the expression of OCLN. DHA also repressed SNAI1 expression in the CLP mouse model and in TNF‐α‐stimulated hCMEC/D3 cells. These data suggest that DHA protects BBB permeability during sepsis by stimulating the expression of OCLN, by downregulating the expression of the SNAI1 transcription factor.

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.

Increase of BACE1, Brain-Renal Risk Factor, Contributes to Kidney Damage in an Alzheimer's Disease Mouse Model

BACKGROUND

It is believed that there is a certain correlation between the brain and kidneys, but it is poorly understood. Many findings suggested that there were previously unknown signaling pathways involving AβPP and BACE1 in the kidney.

OBJECTIVE

Exploring the changes of BACE1 activity in APP23 mouse kidneys, providing evidence for the function of AβPP and BACE1 activity in the kidney.

METHODS

The activity and expression of BACE1 were detected in the kidney of APP23 mice by enzymatic assay and western blotting. The protein expression levels of AβPP, claudin1, occludin, VE-cadherin, and Klotho (membrane-form klotho) were examined by using western blotting. The renal pathological changes of APP23 mice were examined by the routine renal pathological procedures.

RESULTS

In this study, we found that the AβPP protein level was increased in kidneys of APP23 mice compared with wild-type (WT) mice. Additionally, the activity and expression of BACE1 were increased in kidneys of APP23 mice compared to that of WT. BACE1 was predominantly distributed on the lumen side of renal tubular epithelial cells. The protein levels of Klotho and VE-cadherin were decreased, occludin expression was also decreased, and claudin-1 expression was increased. Renal pathological damage which observed in kidneys of APP23 mice was more serious than that in kidneys of WT mice.

CONCLUSION

Our findings suggest that the increase of AβPP protein levels under Thy-1 neuron promoter in the APP23 mice promoted the increase of renal BACE1 expression and enzymatic activity in the kidneys. Moreover, certain pathological damage in the kidneys of APP23 mice were observed. APP23 mice are easily affected by external risk factors compared with WT mice.

The Dual Role of Platelets in the Cardiovascular Risk of Chronic Inflammation

Patients with chronic inflammatory diseases often exhibit cardiovascular risk. This risk is associated with the systemic inflammation that persists in these patients, causing a sustained endothelial activation. Different mechanisms have been considered responsible for this systemic inflammation, among which activated platelets have been regarded as a major player. However, in recent years, the role of platelets has become controversial. Not only can this subcellular component release pro- and anti-inflammatory mediators, but it can also bind to different subsets of circulating lymphocytes, monocytes and neutrophils modulating their function in either direction. How platelets exert this dual role is not yet fully understood.

Neonatal Hyperoxia Downregulates Claudin-4, Occludin, and ZO-1 Expression in Rat Kidney Accompanied by Impaired Proximal Tubular Development

Hyperoxia is essential to manage in preterm infants but causes injury to immature kidney. Previous study indicates that hyperoxia causes oxidative damage to neonatal kidney and impairs renal development. However, the underlying mechanisms by which neonatal hyperoxia effects on immature kidney still need to be elucidated. Tight junction, among which the representative proteins are claudin-4, occludin, and ZO-1, plays a crucial role in nephrogenesis and maintaining renal function. Inflammatory cytokines are involved in the pleiotropic regulation of tight junction proteins. Here, we investigated how neonatal hyperoxia affected the expression of key tight junction proteins and inflammatory factors (IL-6 and TNF-α) in the developing rat kidneys and elucidated their correlation with renal injury. We found claudin-4, occludin, and zonula occludens-1 (ZO-1) expression in proximal tubules was significantly downregulated after neonatal hyperoxia. The expression of these tight junction proteins was positively correlated with that of IL-6 and TNF-α, while claudin-4 expression was positively correlated with injury score of proximal tubules in mature kidneys. These findings indicated that impaired expression of tight junction proteins in kidney might be a potential mechanism of hyperoxia-induced nephrogenic disorders. It provides new insights to further study oxidative renal injury and development disorders and will be helpful for seeking potential therapeutics for hyperoxia-induced renal injury in the future.

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.

Cytokine Storm in COVID-19: The Current Evidence and Treatment Strategies

Severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) is the pathogen that causes coronavirus disease 2019 (COVID-19). As of 25 May 2020, the outbreak of COVID-19 has caused 347,192 deaths around the world. The current evidence showed that severely ill patients tend to have a high concentration of pro-inflammatory cytokines, such as interleukin (IL)-6, compared to those who are moderately ill. The high level of cytokines also indicates a poor prognosis in COVID-19. Besides, excessive infiltration of pro-inflammatory cells, mainly involving macrophages and T-helper 17 cells, has been found in lung tissues of patients with COVID-19 by postmortem examination. Recently, increasing studies indicate that the "cytokine storm" may contribute to the mortality of COVID-19. Here, we summarize the clinical and pathologic features of the cytokine storm in COVID-19. Our review shows that SARS-Cov-2 selectively induces a high level of IL-6 and results in the exhaustion of lymphocytes. The current evidence indicates that tocilizumab, an IL-6 inhibitor, is relatively effective and safe. Besides, corticosteroids, programmed cell death protein (PD)-1/PD-L1 checkpoint inhibition, cytokine-adsorption devices, intravenous immunoglobulin, and antimalarial agents could be potentially useful and reliable approaches to counteract cytokine storm in COVID-19 patients.

Changes in the immune function of rainbow trout (Oncorhynchus mykiss) provide insights into strategies against BDE-47 stress

Polybrominated diphenyl ethers (PBDEs) are ubiquitous in marine ecosystems and have been suggested to bioaccumulate in aquatic food webs, with potentially negative impacts on marine organism. In this study, a 21-day experiment was performed under controlled laboratory conditions, in which 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), the most biotoxic PBDE in the marine environment, was fed to rainbow trout (Oncorhynchus mykiss) at concentrations of 50 and 500 ng g^-1 in the diet. BDE-47 significantly decreased the specific growth rate of O. mykiss and was highly concentrated in the liver and head kidney, as evidenced by increased bioaccumulation factor (BAF) values. Tissue observation revealed impairment of the microstructure of the head kidney. Important immune factors in the skin, blood and head kidney were significantly inhibited by BDE-47 treatment (p < 0.05), whereas the respiratory burst activity of macrophages was enhanced. Additionally, immune-related genes were strongly downregulated following BDE-47 exposure (p < 0.05). In a bacterial challenge, the treatment groups had much higher mortality than did the control group (p < 0.05). BDE-47 accumulated and impaired immune organs, and the hierarchy of immune responses was impaired, consequently reducing O. mykiss resistance to pathogen invasion.

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.

Cadmium regulates von Willebrand factor and occludin expression in glomerular endothelial cells of mice in a TNF-α-dependent manner

Background: Cadmium (Cd) is an environmental pollutant that leads to nephrotoxicity. However, the mechanisms of Cd-induced glomerular injury have not been fully clarified. Von Willebrand factor (vWF) and occludin are important endothelial cell markers in renal vasculature. In this study, the effects of Cd on the vWF and occludin expression in mouse glomeruli was investigated.

Objectives: The goal of this study was to analyze the expression of von Willebrand factor and occludin in glomerular endothelial cells of tumor necrosis factor-α^−/− (TNF-α^−/−) mice after treatment with Cd.

Material and methods: C57BL6/J wild-type (WT) mice and TNF-α^−/− mice (n = 6) were treated with Cd, and the kidney tissues were collected. The expression of von Willebrand factor and occludin was detected by using quantitative real-time PCR, immunofluorescence, and immunohistochemistry. In vitro, Human umbilical vascular endothelial cells (HUVECs) were used to examine the regulatory role of TNF-α on expression of von Willebrand factor and occludin.

Results: We found that Cd significantly increases mRNA and protein expressions of von Willebrand factor and occludin in TNF-α^−/− mice, but not in WT mice. In vitro, Cd significantly increased mRNA and protein expression of von Willebrand factor and occludin in HUVECs with TNF-α small interfering RNA (siRNA) transfection.

Conclusions: These results suggest that TNF-α acts to balance homeostasis of glomerular endothelium after Cd treatments.

Vascular Endothelial Cells Activate Peripheral Natural Killer T Cells and Participate in Regulation of Downstream Immune Cascades in Patients with Sepsis

Background

This study investigated the effect of supernatant of endothelial cells stimulated by peripheral blood serum from sepsis patients on phenotype and function of peripheral NKT cells.

Material/Methods

Twenty-one patients with sepsis and 21 healthy subjects were included. Peripheral blood (5 ml) was collected from all patients and healthy subjects. To isolate peripheral blood mononuclear cells (PBMCs), Ficoll lymphocyte separation solution was used. Flow cytometry was carried out to determine NKT cell ratio, activity, and cytokine secretion. Human umbilical vein endothelial cells were cultured with serum from sepsis patients for 48 h before changing to fresh medium, and supernatant was collected. The supernatant was used to co-culture PBMCs before analyzing NKT activity and cytokines.

Results

The ratios of CD3-CD56+NK cells and CD3+CD56+NKT cells were increased in peripheral blood from sepsis patients. Surface receptors p30, G2D, and p44 of CD3+CD56+NKT cells were elevated, while inhibitory receptors NKG2A and 158b were decreased. CD4+ NKT cells in peripheral blood from sepsis patients were enhanced. GranB, IFN-γ, IL-4, and IL-17 in NKT cells from sepsis patients were up-regulated. After co-culture with vascular endothelial cells treated with sepsis serum, expression of p30 and G2D in NKT cells was upregulated, and number of TCRVα24-positive cells was increased. In addition, ratio of CD4+NKT cells was increased, and intracellular expression of IL-4 and IFN-γ was elevated.

Conclusions

The study demonstrates that the level of NKT cells in peripheral blood from sepsis patients is increased, and their activity is enhanced. In addition, vascular endothelial cells from sepsis patients can regulate the activity of NKT cells.

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.