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

Artesunate-multiple pharmacological effects beyond treating malaria

Artesunate, a semisynthetic derivative of artemisinin, is not only recommended as the first-line drug for treating severe malaria but is also a significant member of Artemisinin-based Combination Therapies (ACTs), used in combination with other artemisinin derivatives for treating uncomplicated malaria. Beyond its potent anti-malarial activity, artesunate has garnered considerable attention for its pharmacological effects, which encompass broad-spectrum anti-tumor, anti-viral, and anti-inflammatory properties. It has collectively demonstrated superior drug tolerance, low toxicity, and mild side effects in cell line experiments in vitro, experimental animal models, and clinical drug researches, as a monotherapy or in combination with other agents. Investigating the pharmacological effects of artesunate will facilitate the exploration of novel drug applications and enhance the comprehensive clinical applications.

Topical and systemic effects of medical ozone therapy on epidural fibrosis: Experimental research

INTRODUCTION

Epidural fibrosis (EF) causes adhesions in the epidural distance, resulting in chronic low back and leg pain symptoms during the postoperative period. Currently, ozone is used for treating lumbar disk herniation and low back pain. However, its effect on epidural fibrosis is largely unknown.

MATERIAL AND METHODS

This rodent study examined the histopathological and biochemical effects of ozone therapy on epidural fibrosis. Forty-seven male Sprague-Dawley rats were divided into four groups, as follows: Control Group (CG) (n = 12): Laminectomy was performed, and no substance was applied. Saline Group (SG) (n = 11): Rats underwent intraoperative washing with 50 mL saline after laminectomy. Local Ozone Group (LOG) (n = 12): Rats underwent intraoperative washing with 50 mL ozonated distilled water after laminectomy. Systemic Ozone Group (SOG) (n = 12): Ozone was administered intraperitoneally (0.7 mg/kg) for 7 consecutive days postoperatively. At the end of 4 weeks, all subjects were sacrificed. Histopathological and biochemical data obtained from the tissues were analyzed in terms of EF.

RESULTS

No statistically significant differences regarding EF, spinal cord retraction, inflammation, and fibroblast density were observed between the groups (p = 0.728; p = 0.813; p = 0.152; and p = 0.226, respectively). Hydroxyproline levels were higher in LOG than in SOG (p = 0.007); however, no statistically significant differences were observed among other groups (p > 0.05).

CONCLUSIONS

In our study, we could not record the positive effect of ozone therapy in terms of histopathology and biochemistry with the current doses and application methods. We think that caution should be exercised in the ozone dose and method of application in the clinical approach. In addition, we are of the opinion that statistically significant results can be obtained by creating a treatment protocol that includes different dose applications.

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.

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.

Artesunate Exerts Organ- and Tissue-Protective Effects by Regulating Oxidative Stress, Inflammation, Autophagy, Apoptosis, and Fibrosis: A Review of Evidence and Mechanisms

The human body comprises numerous organs and tissues operating in synchrony, it facilitates metabolism, circulation, and overall organismal function. Consequently, the well-being of our organs and tissues significantly influences our overall health. In recent years, research on the protective effects of artesunate (AS) on various organ functions, including the heart, liver, brain, lungs, kidneys, gastrointestinal tract, bones, and others has witnessed significant advancements. Findings from in vivo and in vitro studies suggest that AS may emerge as a newfound guardian against organ damage. Its protective mechanisms primarily entail the inhibition of inflammatory factors and affect anti-fibrotic, anti-aging, immune-enhancing, modulation of stem cells, apoptosis, metabolic homeostasis, and autophagy properties. Moreover, AS is attracting a high level of interest because of its obvious antioxidant activities, including the activation of Nrf2 and HO-1 signaling pathways, inhibiting the release of reactive oxygen species, and interfering with the expression of genes and proteins associated with oxidative stress. This review comprehensively outlines the recent strides made by AS in alleviating organismal injuries stemming from various causes and protecting organs, aiming to serve as a reference for further in-depth research and utilization of AS.

Postoperative Epidural Fibrosis: Challenges and Opportunities - A Review

Postoperative epidural fibrosis (EF) is still a major limitation to the success of spine surgery. Fibrotic adhesions in the epidural space, initiated via local trauma and inflammation, can induce difficult-to-treat pain and constitute the main cause of failed back surgery syndrome, which not uncommonly requires operative revision. Manifold agents and methods have been tested for EF relief in order to mitigate this longstanding health burden and its socioeconomic consequences. Although several promising strategies could be identified, few have thus far overcome the high translational hurdle, and there has been little change in standard clinical practice. Nonetheless, notable research progress in the field has put new exciting avenues on the horizon. In this review, we outline the etiology and pathogenesis of EF, portray its clinical and surgical presentation, and critically appraise current efforts and novel approaches toward enhanced prevention and treatment.

Pharmacotherapies to prevent epidural fibrosis after laminectomy: a systematic review of in vitro and in vivo animal models

BACKGROUND CONTEXT

Excessive production of epidural fibrosis in the nerve root can be a pain source after laminectomy. Pharmacotherapy is a minimally invasive treatment option to attenuate epidural fibrosis by suppressing proliferation and activation of fibroblasts, inflammation, and angiogenesis, and inducing apoptosis.

PURPOSE

We reviewed and tabulated pharmaceuticals with their respective signaling axes implicated in reducing epidural fibrosis. Additionally, we summarized current literature for the feasibility of novel biologics and microRNA to lessen epidural fibrosis.

STUDY DESIGN/SETTING

Systematic Review.

METHODS

According to the PRISMA guidelines, we systematically reviewed the literature in October 2022. The exclusion criteria included duplicates, nonrelevant articles, and insufficient detail of drug mechanism.

RESULTS

We obtained a total of 2,499 articles from PubMed and Embase databases. After screening the articles, 74 articles were finally selected for the systematic review and classified based on the functions of drugs and microRNAs which included inhibition of fibroblast proliferation and activation, pro-apoptosis, anti-inflammation, and antiangiogenesis. In addition, we summarized various pathways to prevent epidural fibrosis.

CONCLUSION

This study allows a comprehensive review of pharmacotherapies to prevent epidural fibrosis during laminectomy.

CLINICAL SIGNIFICANCE

We expect that our review would enable researchers and clinicians to better understand the mechanism of anti-fibrosis drugs for the clinical application of epidural fibrosis therapies.

Human Infrapatellar Fat Pad Mesenchymal Stem Cell-Derived Extracellular Vesicles Inhibit Fibroblast Proliferation by Regulating MT2A to Reduce Knee Arthrofibrosis

Knee arthrofibrosis is one of the most serious complications of knee surgery; however, its pathogenesis is unclear, and current treatment methods have not achieved satisfactory results. Mesenchymal stem cells (MSCs) have good anti-inflammatory and antifibrotic properties, and studies have reported that human infrapatellar fat pad-derived MSCs (IPFSCs) have the advantages of strong proliferative and differentiating ability, ease of acquisition, and minimal harm to the donor. Increasing evidence has shown that MSCs function through their paracrine extracellular vesicles (EVs). Our study is aimed at exploring the effects of human IPFSC-derived EVs (IPFSC-EVs) on knee arthrofibrosis and the underlying mechanisms in vivo and in vitro. In the in vivo study, injecting IPFSC-EVs into the knee joint cavity effectively reduced surgery-induced knee arthrofibrosis in rats. In the in vitro study, IPFSC-EVs were found to inhibit the proliferation of fibroblasts in the inflammatory environment. Additionally, we screened a potential IPFSC-EV molecular target, metallothionein 2A (MT2A), using RNA sequencing. We found that silencing MT2A partially reversed the inhibitory effect of IPFSC-EVs on fibroblast proliferation in the inflammatory environment. In conclusion, IPFSC-EVs inhibit the progression of knee arthrofibrosis by regulating MT2A, which inhibits fibroblast proliferation in the inflammatory environment.

Antifibrotic Mechanism of Piceatannol in Bleomycin-Induced Pulmonary Fibrosis in Mice

Background: Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal interstitial lung disease characterized by myofibroblast accumulation and extracellular matrix deposition, which lead to irreversible damage of the lung’s architecture and the formation of fibrotic lesions. IPF is also a sequela in serious patients with the coronavirus disease 2019 (COVID-19). The molecular mechanisms under pulmonary fibrosis remain unclear, and there is no satisfactory treatment currently available. Piceatannol (PIC) is a naturally occurring resveratrol analog found in a variety of dietary sources such as grapes, passion fruit, and white tea. It has been reported to inhibit liver fibroblast growth and exhibited various antitumor activities, although its role in pulmonary fibrosis has not been established yet. In the present study, we evaluated the anti-fibrotic role of PIC in bleomycin (BLM)-induced pulmonary fibrosis in mice.

Methods: Mice with BLM-induced pulmonary fibrosis were treated with PIC, and fibrotic changes were measured by hematoxylin-eosin (H&E) staining and hydroxyproline assay. Luciferase assay, Western blot assay, histological analysis, and immunofluorescence staining were used to evaluate the effect of PIC on fibroblast activation and autophagy in mouse embryonic fibroblast cells (NIH-3T3) and human lung fibroblast cells (HFL1). The anti-fibrotic mechanisms of PIC were either confirmed in vivo.

Results: Our results showed that PIC significantly alleviated the bleomycin-induced collagen deposition and myofibroblast accumulation. In vitro and in vivo studies indicated that PIC plays a role in activating autophagy in the process of anti-fibroblast activation. Further mechanism studies demonstrated that PIC can promote autophagy via inhibiting the TGF-β1-Smad3/ERK/P38 signaling pathway, which leads to a decreased number of activated myofibroblasts.

Conclusion: Our study demonstrated for the first time that PIC possesses the protective effects against bleomycin-induced pulmonary fibrosis due to the direct pulmonary protective effects which enhance the effect of autophagy in vitro and in vivo and finally leads to the decreased number of activated myofibroblasts. PIC may serve as a candidate compound for pulmonary fibrosis therapy and attenuates the sequelae of SARS-COV-2 pulmonary fibrosis.

FAM172A supervises ER (endoplasmic reticulum) stress-triggered autophagy in the epidural fibrosis process

Backgrounds

Lumbar laminectomy is usually utilized for lumbar disc herniation (LDH), but also causes epidural fibrosis (EF) process associated with abnormal proliferation of fibroblasts. FAM172A is associated with ER stress and cell proliferation, but its mechanism was unclear, especially in the process of EF.

Methods

Therefore, the regulation of FAM172A on the calcium flux and autophagy in fibroblasts were investigated by inducing ER stress with tunicamycin and upexpression or downexpression of FAM172A. The calcium flux was determined using Fluo-3, and autophagy was examined with immunofluorescence or western blot for LC3, Beclin-1, ATG-5, and p62. Moreover, the apoptotic protein of Bax and Bcl-2 was detected, too. Furthermore, the laminectomy model was constructed and then dealt with overexpression of FAM172A.

Results

Tunicamycin-induced endoplasmic reticulum (ER) stress and autophagy process in fibroblasts were associated with the calcium flux regulated by FAM172A, especially in EF cells. Besides, tunicamycin induced autophagy and suppressed cell apoptosis of fibroblasts. Furthermore, FAM72A repressed the proliferation of fibroblasts and the process of EF in the laminectomy model through the mediation of the autophagy process.

Conclusions

Tunicamycin-induced endoplasmic reticulum (ER) stress in fibroblasts was associated with calcium flux mediated by FAM172A. FAM72A participated in the autophagy regulation of fibroblasts and maybe the key interaction regulator of apoptosis and autophagy in fibroblasts, especially for epidural scar cells.

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.

Quercetin inhibits fibroblasts proliferation and reduces surgery-induced epidural fibrosis via the autophagy-mediated PI3K/Akt/mTOR pathway

Epidural fibrosis (EF) is a serious complication when the patients suffer from operations of lumbar laminectomy. It is reported that quercetin plays a positive role in the prevention of various fibrotic diseases. However, the role of quercetin in the prevention of epidural fibrosis (EF) and its possible mechanism are unclear. Fibroblast proliferation is considered to be the main cause of epidural fibrosis.Autophagy is a lysosomal degradation pathway that is essential for survival, differentiation, development, and homeostasis.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 quercetin, a polyphenol derived from plants. In vivo, the effect of quercetin on reducing epidural fibrosis was confirmed via histological staining and immunohistochemical analysis. The results showed that quercetin had significant suppressive effects on epidural fibrosis following laminectomy in rats.In vitro,, cell counting kit-8 (CCK-8), Western blot analysis, immunofluorescence and Edu staining, TUNEL staining and transmission electron microscopy were used to detect the effects of quercetin on the proliferation and apoptosis of fibroblasts and explore the possible signal transduction pathway. Results indicated that quercetin could induce autophagy and inhibit proliferation in fibroblasts. In conclusion, Quercetin could regulate fibroblast proliferation, apoptosis, migration and other biological behaviors through autophagy, thereby preventing epidural fibrosis. The specific corresponding pathway may be the PI3K/Akt/mTOR signaling pathway.

Verifying the outcomes of artesunate plus 595-nm PDL in hypertrophic scars via determining BMP-7 and Fas level in model rabbits

BACKGROUND AND OBJECTIVES

Single-use of artesunate (ART) or 595-nm pulsed-dye laser (PDL) has proven clinical efficacy in the treatment of hypertrophic scars (HSs), yet little research has been done on the combined use of ART and PDL. Bone morphogenetic protein-7 (BMP-7) and Fas are recognized to be two important proteins in reducing scar formation. This study was designed to observe the effect of ART combined with 595-nm PDL in the treatment of HS in rabbit models, and investigate the effect of such protocol on the expression of BMP-7 and Fas in rabbit models.

STUDY DESIGN/MATERIALS AND METHODS

Twenty-four New Zealand white rabbits were randomly divided into the control group, ART group, PDL group, and combined treatment (ART + PDL) group. ART was respectively applied to the ART group and combined treatment group. Treatment was once every 2-week for a total of three sessions for both groups. Animals in the PDL group were simply treated with 595-nm PDL. Then, hematoxylin & eosin and Van Gieson straining, immunohistochemical study, enzyme-linked immunosorbent assay (ELISA), Cell counting kit-8 test, western blot assay, and real-time polymerase chain reaction (RT-PCR) were carried out to observe the development of HS samples and expression of BMP-7 and Fas proteins in the sample tissues.

RESULTS

After treatment, the scar samples grew lower and flatter, which was particularly evident in the combined treatment group, with notably inhibited fibroblast and collagen compared to other groups (p < 0.001). Western blot assay and RT-PCR demonstrated that the expression of BMP-7 was most increased in scar samples treated by ART + PDL. BMP-7 level was correspondingly and notably upregulated in treatment groups, especially in the ART + PDL group. In addition, relevant expression of Fas was also higher after treatment, especially in the ART + PDL group compared to either ART or 595-nm PDL group. The difference was significant among groups (p < 0.001).

CONCLUSIONS

Combined use of ART and 595-nm PDL can inhibit HSs in rabbit models via inhibiting extra fibroblast and collagens. The potential mechanism may be involved in enhanced BMP-7 and Fas expression. Our observations may create an alternative therapeutic strategy for HSs in the clinic.

Recent Advances in the Therapeutic Efficacy of Artesunate

Artesunate, a semisynthetic artemisinin derivative, is well-known and used as the first-line drug for treating malaria. Apart from treating malaria, artesunate has also been found to have biological activity against a variety of cancers and viruses. It also exhibits antidiabetic, anti-inflammatory, anti-atherosclerosis, immunosuppressive activities, etc. During its administration, artesunate can be loaded in liposomes, alone or in combination with other therapeutic agents. Administration routes include intragastrical, intravenous, oral, and parenteral. The biological activity of artesunate is based on its ability to regulate some biological pathways. This manuscript reports a critical review of the recent advances in the therapeutic efficacy of artesunate.

Reconstruction of Epidural Fat to Prevent Epidural Fibrosis After Laminectomy in Rabbits

Background: Laminectomy can effectively decompress the spinal cord and expand the vertebral canal. However, the fibrosis that appears may cause adherence and recompression of the spinal cord or/and nerve root, which may cause failed back syndrome (FBS) and make the reexposure process more difficult. Reconstruction of the epidural fat may be an ideal method to achieve satisfactory results. Methods: Thirty-six New Zealand rabbits were randomly divided into three groups: control, extracellular matrix (ECM), and ECM+aMSCs groups. Saline, ECM gel, and ECM+aMSC complex were placed, respectively, at the fifth lumbar vertebrate of the rabbits. Epidural fat and fibrosis formation were detected by magnetic resonance imaging (MRI) and histologically at the 4th, 8th, and 12th weeks. Quantitative RT-PCR was used to detect the expression of interleukin 6 (IL-6) and transforming growth factor β (TGF-β). Results: MRI and Oil Red O staining revealed epidural fat formation at the 12th week in the ECM+aMSCs group. Hematoxylin and eosin staining showed that the numbers of fibroblasts in the ECM gel and ECM+aMSCs groups were less than the control group at the 4th and 8th weeks (p < 0.05). Masson's trichrome staining showed that the proportion of collagen fibers in the ECM gel and ECM+aMSCs group was lower than the control group (p < 0.05). Quantitative RT-PCR showed the expressions of TGF-β and IL-6 were lower in the ECM gel and ECM+aMSCs group than those in the control group (p < 0.05) at the 4th week, but higher at the 8th week. Conclusion: We successfully reconstructed the epidural fat with ECM gel and aMSC complex; additionally, IL-6 and TGF-β cytokines were lower at early stage after laminectomy.

The Intricate Interplay between Cell Cycle Regulators and Autophagy in Cancer

Simple Summary

Autophagy is an intracellular catabolic program regulated by multiple external and internal cues. A large amount of evidence unraveled that cell-cycle regulators are crucial in its control. This review highlights the interplay between cell-cycle regulators, including cyclin-dependent kinase inhibitors, cyclin-dependent kinases, and E2F factors, in the control of autophagy all along the cell cycle. Beyond the intimate link between cell cycle and autophagy, this review opens therapeutic perspectives in modulating together these two aspects to block cancer progression.

Abstract

In the past decade, cell cycle regulators have extended their canonical role in cell cycle progression to the regulation of various cellular processes, including cellular metabolism. The regulation of metabolism is intimately connected with the function of autophagy, a catabolic process that promotes the efficient recycling of endogenous components from both extrinsic stress, e.g., nutrient deprivation, and intrinsic sub-lethal damage. Mediating cellular homeostasis and cytoprotection, autophagy is found to be dysregulated in numerous pathophysiological contexts, such as cancer. As an adaptative advantage, the upregulation of autophagy allows tumor cells to integrate stress signals, escaping multiple cell death mechanisms. Nevertheless, the precise role of autophagy during tumor development and progression remains highly context-dependent. Recently, multiple articles has suggested the importance of various cell cycle regulators in the modulation of autophagic processes. Here, we review the current clues indicating that cell-cycle regulators, including cyclin-dependent kinase inhibitors (CKIs), cyclin-dependent kinases (CDKs), and E2F transcription factors, are intrinsically linked to the regulation of autophagy. As an increasing number of studies highlight the importance of autophagy in cancer progression, we finally evoke new perspectives in therapeutic avenues that may include both cell cycle inhibitors and autophagy modulators to synergize antitumor efficacy.

Lupus Susceptibility Region Containing CDKN1B rs34330 Mechanistically Influences Expression and Function of Multiple Target Genes, Also Linked to Proliferation and Apoptosis

OBJECTIVE

In a recent genome-wide association study, a significant genetic association between rs34330 of CDKN1B and risk of systemic lupus erythematosus (SLE) in Han Chinese was identified. This study was undertaken to validate the reported association and elucidate the biochemical mechanisms underlying the effect of the variant.

METHODS

We performed an allelic association analysis in patients with SLE, followed by a meta-analysis assessing genome-wide association data across 11 independent cohorts (n = 28,872). In silico bioinformatics analysis and experimental validation in SLE-relevant cell lines were applied to determine the functional consequences of rs34330.

RESULTS

We replicated a genetic association between SLE and rs34330 (meta-analysis P = 5.29 × 10-22 , odds ratio 0.84 [95% confidence interval 0.81-0.87]). Follow-up bioinformatics and expression quantitative trait locus analysis suggested that rs34330 is located in active chromatin and potentially regulates several target genes. Using luciferase and chromatin immunoprecipitation-real-time quantitative polymerase chain reaction, we demonstrated substantial allele-specific promoter and enhancer activity, and allele-specific binding of 3 histone marks (H3K27ac, H3K4me3, and H3K4me1), RNA polymerase II (Pol II), CCCTC-binding factor, and a critical immune transcription factor (interferon regulatory factor 1 [IRF-1]). Chromosome conformation capture revealed long-range chromatin interactions between rs34330 and the promoters of neighboring genes APOLD1 and DDX47, and effects on CDKN1B and the other target genes were directly validated by clustered regularly interspaced short palindromic repeat (CRISPR)-based genome editing. Finally, CRISPR/dead CRISPR-associated protein 9-based epigenetic activation/silencing confirmed these results. Gene-edited cell lines also showed higher levels of proliferation and apoptosis.

CONCLUSION

Collectively, these findings suggest a mechanism whereby the rs34330 risk allele (C) influences the presence of histone marks, RNA Pol II, and IRF-1 transcription factor to regulate expression of several target genes linked to proliferation and apoptosis. This process could potentially underlie the association of rs34330 with SLE.

IFN-α-2b Inhibits the Proliferation and Migration of Fibroblasts via the TGFβ/Smad Signaling Pathway to Reduce Postoperative Epidural Fibrosis

Epidural fibrosis after lumbar laminectomy refers to a serious complication, and excessive proliferation of fibroblasts is considered the major factor. Interferon-alpha-2b (IFN-α-2b) can exert antiviral and antiproliferative effects, which has been suggested to effectively prevent several fibrotic diseases. However, the effect of IFN-α-2b on the prevention of epidural fibrosis (EF) and its possible mechanism remain unclear. In this study, in vitro and in vivo experiments were performed to examine the possible mechanism of IFN-α-2b for preventing EF. Cell counting kit-8 (CCK-8), cell cycle test, Edu incorporation, wound healing assay, transwell test, and Western blotting assay were performed to investigate the inhibitory effect of IFN-α-2b on the proliferation and migration of fibroblasts in vitro. As indicated from the results, IFN-α-2b was capable of inhibiting proliferation and migration of fibroblasts and inhibiting the activity of the transforming growth factor β (TGFβ)/Smad signaling pathway. In vivo, the effect of IFN-α-2b on the reduction of EF was determined by performing histological macroscopic evaluation and histological and immunohistochemical staining. As suggested from the results, IFN-α-2b significantly inhibited EF after laminectomy. As revealed from the mentioned results, IFN-α-2b may have a promising application for preventing EF in the future.

Artesunate alleviates diabetic retinopathy by activating autophagy via the regulation of AMPK/SIRT1 pathway

CONTEXT

Artesunate (ART), an antimalarial drug, possesses the ability to induce autophagy and exhibits a protective effect on diabetes.

OBJECTIVE

This study aimed to evaluate the effects of ART on diabetic retinopathy (DR) and to explore the underlying mechanisms.

METHODS

Rats with streptozotocin-induced DR were given intravitreal injection of ART.

RESULTS

ART administration inhibited the increase in retinal thickness and prevented blood-retinal barrier in diabetic rats. Further, vascular leukocyte adherence, microglial activation, inflammatory cytokine, and ROS production in the retinas of diabetic rats were also inhibited by ART. Additionally, ART enhanced autophagy in the retinas of diabetic rats as demonstrated by up-regulated Beclin-1 expression and LC3II/I ratio and down-regulated p62. ART also activated AMP-activated protein kinase (AMPK)/sensor class III histone deacetylase sirtuin 1 (SIRT1) pathway.

CONCLUSIONS

ART, as an autophagy activator, has therapeutic potential in DR treatment.

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.

Artesunate attenuates bone erosion in rheumatoid arthritis by suppressing reactive oxygen species via activating p62/Nrf2 signaling

Accumulating studies have indicated that reactive oxygen species (ROS) may be implicated into the destructive pathological events of rheumatoid arthritis (RA). As an effective antioxidant, artesunate (ARS) was reported to exert antiarthritic effects. However, whether ARS attenuates the bone erosion during RA progression by regulating ROS production remains to be defined. To address this problem, the inhibitive effects of ARS on osteoclastogenesis were observed in vitro. Mechanically, ARS significantly inhibited the NFATc1 signaling accompanied by markedly suppressing ROS production, which was abnormally enhanced during the pathological process of bone erosion. In addition, ARS may function as a potent ROS scavenger and significantly elevate the expression of HO-1 and NQO1 by activating Nrf2. Moreover, p62 accumulation induced by ARS was responsible for the activation of Nrf2, while the knockdown of p62 in osteoclast precursor cells diminished the suppressive effect of ARS on ROS production during osteoclastogenesis. Consistently, we also demonstrated that ARS effectively suppressed ROS production, leading to the inhibition of arthritic bone destruction by activating antioxidant enzyme and Nrf2/p62 signaling in the knee and ankle tissues of CIA rats. Collectively, our data offer the convincing evidence that ARS may inhibit osteoclastogenesis and ameliorate arthritic bone erosion through suppressing the generation of ROS via activating the p62/Nrf2 signaling.

Pirfenidone inhibits fibroblast proliferation, migration or adhesion and reduces epidural fibrosis in rats via the PI3K/AKT signaling pathway

OBJECTIVE

This present study aims to assess the effect of pirfenidone (PFD) on inhibiting fibroblast proliferation, migration or adhesion in vitro and reducing laminectomy-induced epidural fibrosis in vivo.

METHODS

The effect of PFD on proliferation inhibition was evaluated with flow cytometry, CCK-8, EdU and western-blotting assays. Altered properties in migration and adhesion were confirmed by wound-scratch, transwell, immunofluorescence (IF), cell adhesion and western-blotting assays. Additionally, fifty male healthy Sprague-Dawley rats were subjected to laminectomy and then treated with various concentrations of PFD. After 4 weeks, the degree of epidural fibrosis was evaluated by histological analysis.

RESULTS

In vitro, the results of flow cytometry, CCK-8, EdU and western-blotting assays showed that PFD reduced fibroblast proliferation by a dose-dependent manner. And the results of wound-scratch, transwell, IF, cell adhesion and western-blotting assays showed that the migration and adhesion of fibroblasts could be inhibited and the cytoskeleton could also be altered in a dose-dependent manner. And the inhibitory effect of PFD could be partially reversed in the PI3K overexpression experiment, which indicated that the capability of PFD to inhibit fibroblast proliferation, migration and adhesion might be through the PI3K/AKT signaling pathway. In vivo, an obvious reduction in epidural fibrosis was observed in groups topically treated with PFD.

CONCLUSIONS

Topical PFD application obviously suppressed laminectomy-induced epidural fibrosis, possibly by inhibiting fibroblast proliferation, migration and adhesion via the PI3K/AKT signaling pathway. PFD may be a safe and effective pharmaceutical to reduce clinical epidural fibrosis.

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 combination of artesunate and carboplatin exerts a synergistic anti-tumour effect on non-small cell lung cancer

Carboplatin (CBP) is a widely used targeted anticancer therapeutic drug; however, multi-drug resistance induced by the accumulation of CBP eventually causes diseases progression. The anti-malarial drug artesunate (ART) also exerts anticancer effects in various cancers; however, the combined effect of ART and CBP on non-small cell lung cancer (NSCLC) remains unclear. In the present study, the NSCLC cell line A549 was pretreated with various concentrations of CBP, ART and gemcitabine (GEM). 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays were conducted to detect cell viability. Cell apoptosis was evaluated by both flow cytometry and TUNEL apoptotic assay. The expression profiles of cell cycle-related proteins and apoptotic proteins were determined by western blot. Cell clone numbers were visualized using crystal violet staining. Here, we found that both CBP and ART suppressed cell viability, and promoted cell apoptosis, and the combined application of ART and CBP at a lower concentration exhibited synergistic effects. Specifically, the combination of ART and CBP at a lower concentration suppressed cell clone numbers, promoted cell cycle arrest at the G₂ /M phase, and induced the expression of the cell cycle and apoptosis-related proteins BAX, p21, p53, and Caspase-3, while decreasing Bcl-2 and Cyclin B1 expression. Based on these results, we concluded that combined application of ART and CBP exerts synergistic anti-tumour effects on NSCLC by enhancing cell apoptosis in a mitochondria-dependent manner.

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.

Modulation of Autophagy for Controlling Immunity

Autophagy is an essential process that maintains physiological homeostasis by promoting the transfer of cytoplasmic constituents to autophagolysosomes for degradation. In immune cells, the autophagy pathway plays an additional role in facilitating proper immunological functions. Specifically, the autophagy pathway can participate in controlling key steps in innate and adaptive immunity. Accordingly, alterations in autophagy have been linked to inflammatory diseases and defective immune responses against pathogens. In this review, we discuss the various roles of autophagy signaling in coordinating immune responses and how these activities are connected to pathological conditions. We highlight the therapeutic potential of autophagy modulators that can impact immune responses and the mechanisms of action responsible.