Artesunate attenuates unilateral ureteral obstruction-induced renal fibrosis by regulating the expressions of bone morphogenetic protein-7 and uterine sensitization-associated gene-1 in rats

Chitosan-Artesunate nanoparticles: A dual anti-fibrotic and anti-inflammatory strategy for preventing bleb fibrosis post-glaucoma filtration surgery

Glaucoma filtration surgery (GFS) effectively lowers intraocular pressure in glaucoma patients, but postoperative bleb fibrosis often leads to surgical failure. Artesunate (ART) has demonstrated antifibrotic potential; however, its clinical use is limited by poor solubility and rapid degradation. This study aimed to develop chitosan-ART nanoparticles (CS@ART NPs) to improve ART's therapeutic efficacy in preventing bleb fibrosis. CS@ART NPs were synthesized using an ionic gelation method for chitosan encapsulation. Their characterization, including analyses of morphology, hydrodynamic properties, surface charge, encapsulation efficiency, drug release kinetics, stability, chemical structure, and mucoadhesive interactions, was carried out using various techniques such as TEM, DLS, zeta potential analysis, HPLC, FT-IR, 1H-NMR, and adhesion assays. The antifibrotic effects were evaluated in a rabbit GFS model through subconjunctival injection. Histological analysis as well as immunohistochemistry for fibrosis markers α-SMA and fibronectin were detected. In vitro studies were conducted using human primary ocular fibroblasts stimulated with TGF-β1 to assess anti-inflammatory and anti-proliferative effects, measured by EdU incorporation, Western blot for signaling pathway components, and cytokine expression. CS@ART NPs exhibited a uniform size distribution (135.73 ± 0.90 nm), stable dispersion, high encapsulation efficiency (86.4%), and sustained drug release. In the GFS model, a single subconjunctival injection of CS@ART significantly reduced collagen deposition, as well as α-SMA and fibronectin expression at the surgical site. In vitro, CS@ART demonstrated superior antifibrotic effects with a significantly lower IC50 for inhibiting fibroblast proliferation compared to ART alone. Mechanically, CS@ART suppressed the Cyclin D1-CDK4/6, TGF-β1/SMAD, and PI3K/Akt signaling pathways. Additionally, CS@ART showed marked anti-inflammatory effects, reducing inflammatory cell infiltration and IL-6 expression. CS@ART NPs play a dual role both alleviate bleb fibrosis and inflammation after GFS as a promising therapeutic strategy for improving surgical outcomes in glaucoma patients.

Exploring Liraglutide's mechanism in reducing renal fibrosis: the Fsp1-CoQ10-NAD(P)H pathway

Studies have confirmed that elevated glucose levels could lead to renal fibrosis through the process of ferroptosis. Liraglutide, a human glucagon-like peptide-1 (GLP-1) analogue, is a potential treatment option for diabetes. This study aimed to examine the potential of liraglutide (LIRA) in inhibiting ferroptosis and reducing high glucose-induced renal fibrotic injury in mice, and whether the Fsp1-CoQ10-NAD(P)H signal pathway is a mechanism for this effect. In our study, we used db/db mice to simulate Type 2 diabetes mellitus (T2DM). The mice were intraperitoneally injected with LIRA (200 µg/kg/d) daily for 6 weeks. Renal function, pathologic changes, lipid peroxidation levels, iron levels, and ferroptosis were assessed. First, LIRA ameliorated renal dysfunction and fibrosis in db/db mice. Second, LIRA inhibited lipid peroxidation by up-regulating T-SOD, GSH-Px, and GSH activities as well as down-regulating the levels of 8-OHDG, MDA, LPO, 4-HNE, 12-Lox, and NOX4 in db/db mice. In addition, LIRA attenuated iron deposition by decreasing the expression of TfR1 and increasing the expression of FPN1. Meanwhile, LIRA reduced high levels of high glucose-induced cell viability decline and intracellular lipid peroxidation. Furthermore, LIRA inhibited ferroptosis by adjusting the Fsp1-CoQ10-NAD(P)H pathway in vivo and in vitro. These findings suggested that LIRA attenuated kidney fibrosis injury in db/db mice by inhibiting ferroptosis through the Fsp1-CoQ10-NAD(P)H pathway.

Artesunate induces HO-1-mediated cell cycle arrest and senescence to protect against ocular fibrosis

Recent research found artesunate could inhibit ocular fibrosis; however, the underlying mechanisms are not fully known. Since the ocular fibroblast is the main effector cell in fibrosis, we hypothesized that artesunate may exert its protective effects by inhibiting the fibroblasts proliferation. TGF-β1-induced ocular fibroblasts and glaucoma filtration surgery (GFS)-treated rabbits were used as ocular fibrotic models. Firstly, we analyzed fibrosis levels by assessing the expression of fibrotic marker proteins, and used Ki67 immunofluorescence, EdU staining, flow cytometry to determine cell cycle status, and SA-β-gal staining to assess cellular senescence levels. Then to predict target genes and pathways of artesunate, we analyzed the differentially expressed genes and enriched pathways through RNA-seq. Western blot and immunohistochemistry were used to detect the pathway-related proteins. Additionally, we validated the dependence of artesunate's effects on HO-1 expression through HO-1 siRNA. Moreover, DCFDA and MitoSOX fluorescence staining were used to examine ROS level. We found artesunate significantly inhibits the expression of fibrosis-related proteins, induces cell cycle arrest and cellular senescence. Knocking down HO-1 in fibroblasts with siRNA reverses these regulatory effects of artesunate. Mechanistic studies show that artesunate significantly inhibits the activation of the Cyclin D1/CDK4-pRB pathway, induces an increase in cellular and mitochondrial ROS levels and activates the Nrf2/HO-1 pathway. In conclusion, the present study identifies that artesunate induces HO-1 expression through ROS to activate the antioxidant Nrf2/HO-1 pathway, subsequently inhibits the cell cycle regulation pathway Cyclin D1/CDK4-pRB in an HO-1-dependent way, induces cell cycle arrest and senescence, and thereby resists periorbital fibrosis.

Therapeutic Implications of Ferroptosis in Renal Fibrosis

Renal fibrosis is a common feature of chronic kidney disease (CKD), and can lead to the destruction of normal renal structure and loss of kidney function. Little progress has been made in reversing fibrosis in recent years. Ferroptosis is more immunogenic than apoptosis due to the release and activation of damage-related molecular patterns (DAMPs) signals. In this paper, the relationship between renal fibrosis and ferroptosis was reviewed from the perspective of iron metabolism and lipid peroxidation, and some pharmaceuticals or chemicals associated with both ferroptosis and renal fibrosis were summarized. Other programmed cell death and ferroptosis in renal fibrosis were also firstly reviewed for comparison and further investigation.

Effectiveness of artesunate combined with fractional CO2 laser in a hypertrophic scar model with underlying mechanism

BACKGROUND AND OBJECTIVES

Both artesunate and fractional CO2 laser have been proved effective in the treatment of hypertrophic scars, yet little data are available for the efficacy of artesunate combined with fractional CO2 laser. In order to assess the pre-clinical significance and the underlying mechanism of this combined treatment profile, we attempted to observe the effectiveness of this therapy in rabbit models through determining the expression of BMP-7 and Fas.

MATERIALS AND METHODS

Twenty-Four New Zealand white rabbits with established hypertrophic scar samples were randomly divided into control group and three treatment groups. Artesunate (20 μl/cm2) was injected into the rat's scar of artesunate and combination groups, while fractional CO2 laser (Combo mode, deep energy:10 mJ, super energy: 50 mJ) was applied to rats in fractional CO2 laser and combination groups at week 4 after model establishment. All rabbits underwent a total of 3 sessions of treatment once every 2 weeks. Histological and immunohistochemistry study, Western blot assay, cell viability, ELISA and RT-QPCR were performed at week 10 to observe the aspects of hypertrophic scar sample changes and expression of BMP-7 and Fas in the scar tissues.

RESULTS

Compared with control group, hypertrophic scars and the collagen fibers were significantly inhibited after treatment, and higher inhibition was seen in the samples in combination group compared to that in artesunate and fractional CO2 laser groups (P < 0.01). Meanwhile, BMP-7 and Fas expressions were both notably increased in all treatment groups, and upregulation of the two proteins was dominant in combination group (P < 0.01).

CONCLUSIONS

Artesunate combined with fractional CO2 laser is effective in hypertrophic scarring in this rabbit model. Our findings can serve as a potential alternative strategy to treatment of hypertrophic scar in clinical practice.

Therapeutic and delivery strategies of phytoconstituents for renal fibrosis

Chronic kidney disease (CKD) is one of the most common diseases endangering human health and life. By 2030, 14 per 100,000 people may die from CKD. Renal fibrosis (RF) is an important intermediate link and the final pathological change during CKD progression to the terminal stage. Therefore, identifying safe and effective treatment methods for RF has become an important goal. In 2018, the World Health Organization introduced traditional Chinese medicine into its effective global medical program. Various phytoconstituents that affect the RF process have been extracted from different plants. Here, we review the potential therapeutic capabilities of active phytoconstituents in RF treatment and discuss how phytoconstituents can be structurally modified or combined with other ingredients to enhance efficiency and reduce toxicity. We also summarize phytoconstituent delivery strategies to overcome renal barriers and improve bioavailability and targeting.

Uterine Sensitization-Associated Gene-1 in the Progression of Kidney Diseases

Uterine sensitization-associated gene-1 (USAG-1), originally identified as a secretory protein preferentially expressed in the sensitized rat endometrium, has been determined to modulate bone morphogenetic protein (BMP) and Wnt expression to play important roles in kidney disease. USAG-1 affects the progression of acute and chronic kidney damage and the recovery of allograft kidney function by regulating the BMP and Wnt signaling pathways. Moreover, USAG-1 has been found to be involved in the process of T cell immune response, and its ability to inhibit germinal center activity and reduce humoral immunity is of great significance for the treatment of autoimmune nephropathy and antibody-mediated rejection (AMR) after renal transplantation. This article summarizes the many advances made regarding the roles of USAG-1 in the progression of kidney disease and outlines potential treatments.

Phospholipase Cγ Signaling in Bone Marrow Stem Cell and Relevant Natural Compounds Therapy

Excessive bone resorption has been recognized play a major role in the development of bone-related diseases such as osteoporosis, rheumatoid arthritis, Paget's disease of bone, and cancer. Phospholipase Cγ (PLCγ) family members PLCγ1 and PLCγ2 are critical regulators of signaling pathways downstream of growth factor receptors, integrins, and immune complexes and play a crucial role in osteoclast. Ca2+ signaling has been recognized as an essential pathway to the differentiation of osteoclasts. With growing attention and research about natural occurring compounds, the therapeutic use of natural active plant-derived products has been widely recognized in recent years. In this review, we summarized the recent research on PLCγ signaling in bone marrow stem cells and the use of several natural compounds that were proven to inhibit RANKL-mediated osteoclastogenesis via modulating PLCγ signaling pathways.

Effect of Artesunate Combined With Fractional CO2 Laser on the Hypertrophic Scar in a Rabbit Model

BACKGROUND AND OBJECTIVES

Hypertrophic scar (HS), a common complication in wound healing, is characterized by the disarrangement of collagen, fibers, and extracellular matrix. Artesunate (ART) can inhibit the abnormal formation of fibroblasts and collagens. Fractional CO2 laser (FCO2 L) can facilitate tissue remodeling and the absorption of drugs into ablative microthermal columns in HS. So far, no research has investigated the efficacy of ART combined with an FCO2 L in treating HS. To investigate the theoretical basis and clinical significance of this combination, we established a rabbit model of HS to observe the change in the expression of transforming growth factor β1 (TGF-β1) and proliferating cell nuclear antigen (PCNA).

STUDY DESIGN/MATERIALS AND METHODS

Forty New Zealand white rabbits were randomly divided into four groups: control group, ART group, FCO2 L group, and ART + FCO2 L (combination) group. Four wounds were surgically established in the ear of each rabbit and allowed to develop into HS. ART (20 μL/cm2 ) was injected in ART and combination groups, and FCO2 L (combo mode, deep energy:10m J, super energy: 50 mJ) in FCO2 L and combination groups on the 28th day after HS occurred. Three rounds of treatment were applied (once every 14 days). HS samples were measured by hematoxylin and eosin staining, Van Gieson staining, immunohistochemistry, and Western blot analysis on the 70th day.

RESULTS

The morphological and histopathological changes in HS were significant. HSs were smoother and smaller and the collagen fibers were thinner and less disordered in the combination group than those in ART and FCO2 L groups. Meanwhile, the hypertrophic index (HI), fiber density (NA), and collagen fiber content (AA) were lower in the combination group (1.54 ± 0.15, 3.30 ± 0.22, 30.37 ± 1.41%) than in the ART group (2.51 ± 0.22, 4.69 ± 0.16, 44.68 ± 2.30%) and FCO2 L group (1.99 ± 0.14, 4.13 ± 0.12, 37.74 ± 1.38%) (P < 0.01). Additionally, the expressions of TGF-β1 and PCNA protein were suppressed in the ART group (0.30 ± 0.03, 0.25 ± 0.03) and FCO2 L group (0.35 ± 0.03, 0.32 ± 0.05), and the suppression was more significant in the combination group(0.07 ± 0.02, 0.07 ± 0.02) (P < 0.01).

CONCLUSIONS

The combination of ART and FCO2 L can effectively reduce HS in the rabbit model. This is the first report about this combination in the treatment of HS. A novel treatment is expected to be based on our findings. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.

Artemisinin and artemisinin derivatives as anti-fibrotic therapeutics

Fibrosis is a pathological reparative process that can occur in most organs and is responsible for nearly half of deaths in the developed world. Despite considerable research, few therapies have proven effective and been approved clinically for treatment of fibrosis. Artemisinin compounds are best known as antimalarial therapeutics, but they also demonstrate antiparasitic, antibacterial, anticancer, and anti-fibrotic effects. Here we summarize literature describing anti-fibrotic effects of artemisinin compounds in in vivo and in vitro models of tissue fibrosis, and we describe the likely mechanisms by which artemisinin compounds appear to inhibit cellular and tissue processes that lead to fibrosis. To consider alternative routes of administration of artemisinin for treatment of internal organ fibrosis, we also discuss the potential for more direct oral delivery of Artemisia plant material to enhance bioavailability and efficacy of artemisinin compared to administration of purified artemisinin drugs at comparable doses. It is our hope that greater understanding of the broad anti-fibrotic effects of artemisinin drugs will enable and promote their use as therapeutics for treatment of fibrotic diseases.

The Potential Roles of Artemisinin and Its Derivatives in the Treatment of Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) is a chronic disease that has become a global public health problem. Studies on T2DM prevention and treatment mostly focus on discovering therapeutic drugs. Artemisinin and its derivatives were originally used as antimalarial treatments. In recent years, the roles of artemisinins in T2DM have attracted much attention. Artemisinin treatments not only attenuate insulin resistance and restore islet ß-cell function in T2DM but also have potential therapeutic effects on diabetic complications, including diabetic kidney disease, cognitive impairment, diabetic retinopathy, and diabetic cardiovascular disease. Many in vitro and in vivo experiments have confirmed the therapeutic utility of artemisinin and its derivatives on T2DM, but no article has systematically demonstrated the specific role artemisinin plays in the treatment of T2DM. This review summarizes the potential therapeutic effects and mechanism of artemisinin and its derivatives in T2DM and associated complications, providing a reference for subsequent related research.

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.

Artesunate prevents knee intraarticular adhesion via PRKR-like ER kinase (PERK) signal pathway

Background

Intraarticular scar adhesion refers to a serious complication caused by knee surgery or trauma, leading to various sequelae (e.g., articular cartilage degeneration and knee joint stiffness). Artesunate (ART) has exhibited an effect to suppress fibroblast proliferation, whereas the exact mechanism remains unclear. This study aims to delve into the possible mechanism of ART in suppressing joint adhesion.

Methods

The effect of ART on reduced intraarticular adhesions was ascertained by histological staining and immunohistochemical analysis through vivo experiments. Cell Counting Kit-8 (CCK-8) assay, Western blot analysis, flow cytometry, and tunnel staining were used to detect the effect of ART in promoting fibroblast apoptosis and delve into its possible signaling pathway.

Results

The results of hematoxylin-eosin (HE) staining suggested that the number of fibroblasts decreased with the increase in ART concentration. The results of Masson staining were similar, with the increase in concentration, the collagen content decreased. Immunohistochemical results showed that the expression of endoplasmic reticulum stress (ERS) characteristic proteins 78 kDa glucose-regulated protein 78 (GRP78) and C/EBP homologous protein (CHOP) increased in a concentration-dependent manner. CCK-8 results suggested that ART could inhibit fibroblast viability in a concentration- and time-dependent manner. Results of flow cytometry, tunnel staining, and Western blot suggested the apoptosis of fibroblasts occurred after ART treatment. Cells with caspase inhibitors were treated, and apoptotic proteins cleaved-poly ADP-ribose polymerase (cleaved PARP) and cleaved-caspase 3 were detected; the results showed that the apoptotic effect of ART was reduced. The expressions of ERS-related protein CHOP and apoptosis-related protein Bax were upregulated, while the expression of Bcl-2 was downregulated, and the ratio of Bax/Bcl-2 increased in a concentration-dependent manner. Continuous detection of PRKR-like ER kinase (PERK) pathway-related proteins showed that the expression of p-PERK and phosphorylating eukaryotic initiation factor 2α (p-eIF2α) increased in a time-dependent and concentration-dependent manner. PERK pathway inhibitors could partially inhibit ART-mediated apoptosis through PERK pathway.

Conclusions

ART can promote fibroblast apoptosis through PERK pathway, a classical ERS pathway, and thus prevent fibrosis in the surgical area after joint surgery.

Overexpression of BMP‑7 reverses TGF‑β1‑induced epithelial‑mesenchymal transition by attenuating the Wnt3/β‑catenin and TGF-β1/Smad2/3 signaling pathways in HK‑2 cells

Tubular epithelial cells undergoing epithelial-mesenchymal transition (EMT) is a crucial event in the progression of renal interstitial fibrosis (RIF). Bone morphogenetic protein-7 (BMP-7) has been reported to exhibit anti-fibrotic functions in various renal diseases. However, the function of BMP-7 in regulating EMT and the progression of RIF remains largely unknown. The aim of the present study was to examine the potential effect of BMP-7 on transforming growth factor β1 (TGF-β1)-induced EMT and the underlying mechanisms by which BMP-7 exerted its effects. Human renal proximal tubular epithelial cells (HK-2) were treated with TGF-β1 for various time periods and at various concentrations and lentiviral vectors were used to overexpress BMP-7. Cell Counting Kit-8 and Transwell assays were used to evaluate the viability and migration of HK-2 cells in vitro. EMT was estimated by assessing the changes in cell morphology and the expression of EMT markers. In addition, the activation of the Wnt3/β-catenin and TGF-β1/Smad2/3 signaling pathways were analyzed using western blotting. TGF-β1 induced EMT in a time- and dose-dependent manner in HK-2 cells. Treatment with TGF-β1 induced morphological changes, decreased cell viability and the expression of E-cadherin, increased cell migration and the expression of α-smooth muscle actin, fibroblast-specific protein 1, collagen I and vimentin, and activated the Wnt3/β-catenin and TGF-β1/Smad2/3 signaling pathways in HK-2 cells. However, BMP-7 overexpression notably reversed all these effects. These results suggest that BMP-7 effectively suppresses TGF-β1-induced EMT through the inhibition of the Wnt3/β-catenin and TGF-β1/Smad2/3 signaling pathways, highlighting a potential novel anti-RIF strategy.

Effect of artesunate and relation with TGF-β1 and SMAD3 signaling on experimental hypertrophic scar model in rabbit ear

Artesunate (ART) is the derivative of artemisinin isolated from the traditional Chinese medicine qinghao. Although several studies reported the efficiency of artesunate in the treatment of malaria, inhibiting fibroblasts and collagen synthesis, the association between artesunate and scar formation is unclear. The research was designed to study the significance of artesunate (ART) on the expression of transforming growth factor (TGF-β1) and small mother against decapentaplegic (SMAD3) in rabbit's ear hypertrophic scar model. Twenty-four New Zealand white rabbits were randomly divided into six groups: control group, matrix group, low-concentration artesunate group (0.48%), medium-concentration artesunate group (0.96%), high-concentration artesunate group (1.92%) and silicone gel group. Punched defects were established on each rabbit’s ear which resulted in a hypertrophic scar. On the 28th day, topical artesunate creams were applied twice a day except on the control group. On the 56th day, scar samples were collected for histopathology and immunoassay. Hematoxylin and eosin staining, Van Gieson staining, immunohistochemistry and Western blot analysis were done. Amongst the six groups, findings showed that the medium-concentration artesunate group (0.92%) efficiently decreased hypertrophic scar formation and significantly reduced fibroblasts and collagen synthesis. The results had also shown a decrease in the expression of transforming growth factor (TGF-β1) and declined small signal mother against decapentaplegic (Smad3). The overall study shows efficacy and mechanism of artesunate. It concluded that the medium concentration of artesunate (0.92%) could be an effective therapeutic agent for hypertrophic scars.

Telbivudine antagonizes TLR4 to inhibit the epithelial-to-mesenchymal transition in human proximal tubular epithelial cells in vitro

The antiviral drug Telbivudine (LdT) has an extrahepatic pharmaceutical effect that improves renal inflammation and tubulointerstitial fibrosis. However, the exact mechanism of action requires further investigation. Toll-like receptor 4 (TLR4) is involved in several physiological processes, including inflammation, fibrosis, innate immunity, and hepatitis B virus-associated glomerulonephritis. The epithelial-to-mesenchymal transition (EMT) is the characteristic pathological change in tubulointerstitial fibrosis. In this study, we used transforming growth factor-β (TGF-β) to stimulate human proximal tubular epithelial (HK-2) cells to investigate the effects of LdT in EMT. In addition, we treated HK-2 cells with a TLR4 agonist, lipopolysaccharide, to determine the effect of LdT on TLR4. The results indicated that LdT inhibited the expression of TLR4 and its downstream proteins. It also decreased the release of inflammatory factors, downregulated the TGF-β/Smad signaling pathway, and reversed the EMT changes seen in HK-2 cells. In conclusion, LdT antagonized TLR4 to inhibit EMT in proximal tubular epithelial cells.

Transcription profiling of artemisinin-treated diabetic nephropathy rats using high-throughput sequencing

Artemisinin (Art) plays a renoprotective role in diabetic nephropathy (DN) rats. However, the differential gene expression profile and underlying molecular mechanism of Art treatment in DN is not well understood. We constructed an animal model of DN by injection of streptozotocin (STZ) in rats. We then examined the profile of differentially expressed genes following administration of Art using RNA-sequencing (KANGCH&EN, Shanghai, China). Five genes identified by RNA-sequencing were randomly selected and validated by qRT-PCR. Bioinformatic analyses were performed to study these differentially expressed genes. We identified a total of 31 genes that were significantly up-regulated in DN samples compared to both normal and Art treatment samples, and 38 genes that were significantly down-regulated in DN samples compared to both normal and Art treatment samples. The identified genes were associated with a list of gene ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways and may be involved in the mechanism underlying Art treatment of DN. Thus, the results from the current study demonstrate that genes are aberrantly expressed after Art treatment and identify promising targets in the treatment of DN with artemisinin.

Artesunate inhibits fibroblasts proliferation and reduces surgery-induced epidural fibrosis via the autophagy-mediated p53/p21waf1/cip1 pathway

Fibroblast proliferation is considered to be a major cause in the process of epidural fibrosis formation. Autophagy is a tightly-regulated catabolic process in charge of degrading intracellular components. Although autophagy has been associated with fibrosis of different tissues, the effect of autophagy on epidural fibrosis is still unknown. The aim of this study was to investigate the function and mechanism of autophagy induced by Artesunate (ART), a classical antimalarial agent extracted from the Chinese medicinal herb. In vitro, the effect of ART on inducing fibroblast autophagy was evaluated via LC3 immunofluorescent staining, Transmission Electron Microscopy (TEM) and western blotting analysis. Moreover, the effect of ART on inhibiting fibroblast proliferation was investigated by CCK-8 assay, EdU incorporation assay, flow cytometry and western blotting analysis. Results indicated that ART could induce autophagy and inhibit proliferation in fibroblasts. The inhibitory effect of ART on fibroblast proliferation was associated with the upregulation of p53 and p21^waf1/cip1 proteins. Intriguingly, 3-MA, a classical autophagy inhibitor, attenuated ART-induced p53/p21^waf1/cip1 pathway activation and fibroblast proliferation inhibition. In vivo, the effect of ART on reducing epidural fibrosis was detected by histological macroscopic assessment, hydroxyproline content analysis, histological and immunohistochemical staining. The results revealed that ART had significant suppressive effects on epidural fibrosis following laminectomy in rats. In conclusion, this research demonstrated that ART could inhibit fibroblast proliferation and reduce epidural fibrosis formation after laminectomy, and the potential mechanism might through autophagy cascade-mediated p53/p21^waf1/cip1 pathway. It might provide a novel reagent for reducing epidural fibrosis after spinal laminectomy surgery.

Artesunate ameliorates high glucose-induced rat glomerular mesangial cell injury by suppressing the TLR4/NF-κB/NLRP3 inflammasome pathway

Inflammatory response is important for the development and progression of diabetic nephropathy (DN). Artesunate (ART), an antimalarial drug, possesses anti-inflammatory effect and exhibits protective effect on chronic kidney diseases. However, the effect of ART on DN is unknown. The aim of the present study was to evaluate the effect and the molecular mechanism of ART on DN in an in vitro model. The rat mesangial cell line, HBZY-1, was induced by high glucose (HG; 30 mM d-glucose) in the presence or absence of ART (15 and 30 μg/ml) and incubated for 24 h. We found that HG induced the proliferation of HBZY-1 cells, while treatment with ART inhibited the cell proliferation. Treatment with ART inhibited HG-induced inflammatory cytokines production and expression of extracellular matrix (ECM). Besides, HG induced reactive oxygen species (ROS) and malondialdehyde (MDA) levels, and inhibited the superoxide dismutase (SOD) activity of HBZY-1 cells, and the effects were attenuated by ART treatment. ART decreased HG-induced the expression levels of toll-like receptor 4 (TLR4), myeloid differentiation primary response gene 88 (MyD88), nuclear factor κB (NF-κB) p-p65, and nod-like receptor protein 3 (NLRP3). Inhibition of the TLR4/NF-κB pathway suppressed NLRP3 inflammasome in HBZY-1 cells. In conclusion, ART exhibited protective effect on HG-induced HBZY-1 cells by inhibiting the inflammatory response, oxidative stress and ECM accumulation. The TLR4/NF-κB/NLRP3 inflammasome pathway was involved in the protective effect of ART. The results suggested that ART might be a potential therapy agent for the DN treatment.

Role of artesunate in TGF‑β1‑induced renal tubular epithelial‑mesenchymal transdifferentiation in NRK‑52E cells

The implications of epithelial-mesenchymal transdifferentiation (EMT) have extended beyond the confines of renal fibrosis to renal tubulointerstitial fibrosis. It has been proposed that EMT may be one of the mechanisms involved in the pathogenesis of renal fibrosis. However, the underlying mechanisms remain unknown. Transforming growth factor (TGF)-β1 is considered to be an important cytokine which regulates the transdifferentiation of tubular epithelial cells into myofibroblasts in renal tubulointerstitial fibrosis. In the present study, normal rat kidney tubular epithelial cells (NRK-52E) were treated for 48 h with TGF-β1 (5 ng/ml) and different concentrations of artesunate (ART; 0.01, 0.1 and 1 µg/ml). Western blotting, reverse transcription-semi quantitative polymerase chain reaction analysis and immunofluorescence staining were used to evaluate the expression of bone morphogenetic protein (BMP)-7, uterine sensitization-associated gene (USAG)-1, E-cadherin, α-smooth muscle actin (α-SMA) and extracellular matrix collagen type I (Col I) mRNA. ART was able to attenuate renal injury in a unilateral ureteral obstruction model. However, its anti-fibrotic effect remains to be elucidated. In the present study, it was observed that ART was able to ameliorate the TGF-β1-induced alterations in cellular morphology. In addition, ART inhibited the TGF-β1-induced USAG-1 increase and the decrease in BMP-7. Treatment with ART markedly attenuated the TGF-β1-induced upregulation of α-SMA and downregulation of E-cadherin. Additionally, ART was able to significantly attenuate the deposition of interstitial collagens, including Col I. The results of the present study further verified the therapeutic efficacy of ART in TGF-β1-induced renal interstitial fibrosis. These findings indicated that ART may hold the potential to prevent chronic kidney diseases via the suppression of USAG-1 expression or by increasing BMP-7 expression.

Regulatory effects of electronic beam irradiation on mir-21/smad7-mediated collagen I synthesis in keloid-derived fibroblasts

Keloid scarring is an abnormal pathological scar characterized by excessive fibro proliferation and extracellular matrix deposition. Electronic beam irradiation is commonly used with surgical removal to control high recurrence rates of keloid scarring; however, the mechanism remains unknown. In this study, we used keloid-derived primary fibroblasts (KF) as the cell model, and a dose of 15 Gy energy, followed by quantitative PCR (qPCR), western blotting and gene overexpression/knock down techniques were used to reveal the molecular mechanisms affected by electronic beam irradiation. We found that mir-21 was highly expressed in KF and was downregulated by irradiation. We also showed that smad7 was a direct target of mir-21. Moreover, the expression level of smad7 was low in KF and upregulated by irradiation. We also found that smad7 controls Col-1 synthesis by mediating p38 phosphorylation, and this process was affected by electronic beam irradiation. The regulatory effect of electronic beam irradiation on the expression of mir-21, smad7, p38, p-p38 and Col-1 could be partly restored by mir-21 overexpression achieved by mir-21 mimic transfection. In conclusion, our data demonstrated that mir-21/smad7 regulated Col-1 expression in KF and that electronic beam irradiation was capable of decreasing Col-1 production by modifying mir-21/smad7-mediated p38 activation. This is the first report identifying the effects of electronic beam irradiation on miRNAs, providing a novel strategy to discover the molecular mechanisms of radiotherapy.

Summary: Using primary keloid-derived fibroblasts, we demonstrate that electronic beam irradiation inhibits the recurrence of keloid scarring by suppressing collagen I expression via mir-21/smad7-mediated p38 activation.