The inhibition of activated hepatic stellate cells proliferation by arctigenin through G0/G1 phase cell cycle arrest: Persistent p27Kip1 induction by interfering with PI3K/Akt/FOXO3a signaling pathway

Arctigenin induces activated HSCs quiescence via AMPK-PPARγ pathway to ameliorate liver fibrosis in mice

Arctigenin (ATG), a traditional Chinese herbal medicine, is a natural lignan compound extracted from the seeds of burdock (Arctium lappa L, Asteraceae). As a natural product with multiple biological activities, the effect and mechanism of ATG against liver fibrosis are not fully elucidated yet. In current work, we first discovered that ATG could improve CCl4-induced liver injury reflected by lower plasma ALT and AST levels, liver coefficient and pathological scoring of ballooning. Furthermore, it also could reduce the positive areas of Masson, Sirius red and α-SMA staining, inhibit the expression of fibrosis-related genes (Col1a1, Col3a1, Acta2), and decrease the content of hydroxyproline, indicated ATG treatment had benefits in alleviating CCl4-induced liver fibrosis. In vitro, we observed that ATG can inhibit collagen production stimulated by TGF-β1 in LX2 cells. By analysis of the information obtained from SymMap and GeneCards databases and in vitro validation experiments, ATG was proven to be an indirect PPARγ agonist and its effect on collagen production was dependent on PPARγ. Subsequently, we confirmed that ATG activating AMPK was the contributor of its effect on PPARγ and collagen production. Finally, the transformation of activated hepatic stellate cells was determined after treated with ATG, in which ATG treatment could return activated LX2 cells to quiescence because of the elevated quiescent markers and lipid droplets. Our work has highlighted the potential of ATG in the treatment of liver fibrosis and clarified that ATG can activate AMPK/PPARγ pathway to restore the activated hepatic stellate cell to quiescence thereby improving liver fibrosis.

The role of PI3k/AKT signaling pathway in attenuating liver fibrosis: a comprehensive review

Excessive accumulation of extracellular matrix (ECM) components within the liver leads to a pathological condition known as liver fibrosis. Alcohol abuse, non-alcoholic fatty liver disease (NAFLD), autoimmune issues, and viral hepatitis cause chronic liver injury. Exploring potential therapeutic targets and understanding the molecular mechanisms involved in liver fibrosis are essential for the development of effective interventions. The goal of this comprehensive review is to explain how the PI3K/AKT signaling pathway contributes to the reduction of liver fibrosis. The potential of this pathway as a therapeutic target is investigated through a summary of results from in vivo and in vitro studies. Studies focusing on PI3K/AKT activation have shown a significant decrease in fibrosis markers and a significant improvement in liver function. The review emphasizes how this pathway may prevent ECM synthesis and hepatic stellate cell (HSC) activation, ultimately reducing the fibrotic response. The specific mechanisms and downstream effectors of the PI3K/AKT pathway in liver fibrosis constitute a rapidly developing field of study. In conclusion, the PI3K/AKT signaling pathway plays a significant role in attenuating liver fibrosis. Its complex role in regulating HSC activation and ECM production, demonstrated both in vitro and in vivo, underscores its potential as a effective therapeutic approach for managing liver fibrosis and slowing disease progression. A comprehensive review of this field provides valuable insights into its future developments and implications for clinical applications.

Anti-Proliferative Effects of Lidocaine as an Autophagy Inducer in Bladder Cancer via Intravesical Instillation: In Vitro and Xenograft Mouse Model Experiments

Lidocaine exerts potential anti-tumor effects on various cancer cell lines, and its intravesical instillation is considered safer than intravenous administration for bladder cancer. However, the mechanisms underlying its anti-tumor effects have not been fully elucidated. Here, we aimed to elucidate the anti-tumor molecular mechanisms of lidocaine in bladder cancer cells and a xenograft model to substantiate the efficacy of its intravesical administration. We investigated the anti-proliferative and autophagyinducing activities of lidocaine in Nara Bladder Tumor No. 2 (NBT-II) rat bladder carcinoma cells using cell viability, flow cytometry, a wound healing assay, and western blotting. We also established a xenograft mouse model of bladder cancer, and cancer growth was examined using in vivo bioluminescence imaging. Lidocaine decreased cell viability, induced G0/G1 phase cell cycle arrest, and inhibited cell migration partially via glycogen synthase kinase (GSK) 3β phosphorylation. Moreover, a combination of lidocaine and SB216763 (a GSK3β inhibitor) suppressed autophagy-related protein expression. Bafilomycin-A1 with lidocaine significantly enhanced microtubule-associated protein 1A/1B-light chain (LC3B) expression; however, it decreased LC3B expression in combination with 3-methyladenine compared to lidocaine alone. In the xenograft mouse model, the bladder cancer volume was reduced by lidocaine. Overall, lidocaine exerts anti-proliferative effects on bladder cancer via an autophagy-inducing mechanism.

Natural bioactive compounds and FOXO3a in cancer therapeutics: An update

Forkhead box protein 3a (FOXO3a) is a transcription factor that regulates various downstream targets upon its activation, leading to the upregulation of tumor suppressor and apoptotic pathways. Hence, targeting FOXO3a is an emerging strategy for cancer prevention and treatment. Recently, Natural Bioactive Compounds (NBCs) have been used in drug discovery for treating various disorders including cancer. Notably, several NBCs have been shown as potent FOXO3a activators. NBCs upregulate FOXO3a expressions through PI3K/Akt, MEK/ERK, AMPK, and IκB signaling pathways. FOXO3a promotes its anticancer effects by upregulating the levels of its downstream targets, including Bim, FasL, and Bax, leading to apoptosis. This review focuses on the dysregulation of FOXO3a in carcinogenesis and explores the potent FOXO3a activating NBCs for cancer prevention and treatment. Additionally, the review evaluates the safety and efficacy of NBCs. Looking ahead, NBCs are anticipated to become a cost-effective, potent, and safer therapeutic option for cancer, making them a focal point of research in the field of cancer prevention and treatment.

Therapeutic Potential of Benzimidazoisoquinoline Derivatives in Alleviating Murine Hepatic Fibrosis

Short Title: Benzimidazoisoquinoline derivatives as potent antifibrotics Hepatic fibrosis is a pathological condition of liver disease with an increasing number of cases worldwide. Therapeutic strategies are warranted to target the activated hepatic stellate cells (HSCs), the collagen-producing cells, an effective strategy for controlling the disease progression. Benzimidazoisoquinoline derivatives were synthesized as hybrid molecules by the combination of benzimidazoles and isoquinolines to evaluate their anti-fibrotic potential using an in-vitro and in-vivo model of hepatic fibrosis. A small library of benzimidazoisoquinoline derivatives (1-17 and 18-21) was synthesized from 2-aryl benzimidazole and acetylene functionalities through C-H and N-H activation. Compounds (10 and its recently synthesized derivatives 18-21) depicted a significant decrease in PDGF-BB and/or TGFβ-induced proliferation (1.7-1.9 -fold), migration (3.5-5.0 -fold), and fibrosis-related gene expressions in HSCs. These compounds could revert the hepatic damage caused by chronic exposure to hepatotoxicants, ethanol, and/or carbon tetrachloride as evident from the histological, biochemical, and molecular analysis. Anti-fibrotic effect of the compounds was supported by the decrease in the malondialdehyde level, collagen deposition, and gene expression levels of fibrosis-related markers such as α-SMA, COL1α1, PDGFRβ, and TGFRIIβ in the preclinical models of hepatic fibrosis. In conclusion, the synthesized benzimidazoisoquinoline derivatives (compounds 18, 19, 20, and 21) possess anti-fibrotic therapeutic potential against liver fibrosis.

Progress in molecular mechanisms of coronary microvascular dysfunction

Coronary microvascular dysfunction is a high-risk factor for many cardiovascular events. However, because of multiple risk factors and limited understanding about its underlying pathophysiological mechanisms, it was easily misdiagnosed. Therefore, its clinical diagnosis and treatment were greatly restricted. Coronary microcirculation refers to microvessels that play an important role in the physiological regulation of myocardial perfusion and regulating blood flow distribution, fulfilling myocardial metabolic needs and moderating peripheral vascular resistance. In coronary microvascular dysfunction, vascular endothelial celldamage is a critical link. The main feature of early coronary microvascular dysfunction is the impairment of endothelial cell proliferation, adhesion, migration, apoptosis, and secretion. Moreover, coronary microvascular dysfunction risk factors include hyperglycemia, lipid metabolism disorders, ischemia-reperfusion injury, aging, and hypertension, similar to coronary atherosclerosis. There are various mechanisms by which these risk factors harm endothelial function and cause microcirculatory disturbances. Therefore, we reviewed coronary microvascular dysfunction's risk factors and pathogenesis in this article.

N6-methyladenosine-modified circIRF2, identified by YTHDF2, suppresses liver fibrosis via facilitating FOXO3 nuclear translocation

Circular RNA (circRNA) has been implicated in liver fibrosis and modulated by multiple elusive molecular mechanisms, while the effects of N6-methyladenosine (m6A) modification on circRNA are still elusive. Herein, we identify circIRF2 from our circRNA sequencing data, which decreased in liver fibrogenesis stage and restored in resolution stage, indicating that dysregulated circIRF2 may be closely associated with liver fibrosis. Gain/loss-of-function analysis was performed to evaluate the effects of circIRF2 on liver fibrosis at both the fibrogenesis and resolution in vivo. Ectopic expression of circIRF2 attenuated liver fibrogenesis and HSCs activation at the fibrogenesis stage, whereas downregulation of circIRF2 impaired mouse liver injury repair and inflammation resolution. Mechanistically, YTHDF2 recognized m6A-modified circIRF2 and diminished circIRF2 stability, partly accounting for the decreased circIRF2 in liver fibrosis. Microarray was applied to investigate miRNAs regulated by circIRF2, our data elucidate cytoplasmic circIRF2 may directly harbor miR-29b-1-5p and competitively relieve its inhibitory effect on FOXO3, inducing FOXO3 nuclear translocation and accumulation. Clinically, circIRF2 downregulation was prevalent in liver fibrosis patients compared with healthy individuals. In summary, our findings offer a novel insight into m6A modification-mediated regulation of circRNA and suggest that circIRF2 may be an exploitable prognostic marker and/or therapeutic target for liver fibrosis.

Therapeutic potential and mechanism of Chinese herbal medicines in treating fibrotic liver disease

Liver fibrosis is a pathological condition characterized by replacement of normal liver tissue with scar tissue, and also the leading cause of liver-related death worldwide. During the treatment of liver fibrosis, in addition to antiviral therapy or removal of inducers, there remains a lack of specific and effective treatment strategies. For thousands of years, Chinese herbal medicines (CHMs) have been widely used to treat liver fibrosis in clinical setting. CHMs are effective for liver fibrosis, though its mechanisms of action are unclear. In recent years, many studies have attempted to determine the possible mechanisms of action of CHMs in treating liver fibrosis. There have been substantial improvements in the experimental investigation of CHMs which have greatly promoted the understanding of anti-liver fibrosis mechanisms. In this review, the role of CHMs in the treatment of liver fibrosis is described, based on studies over the past decade, which has addressed the various mechanisms and signaling pathways that mediate therapeutic efficacy. Among them, inhibition of stellate cell activation is identified as the most common mechanism. This article provides insights into the research direction of CHMs, in order to expand its clinical application range and improve its effectiveness.

A systematic review on botany, ethnopharmacology, quality control, phytochemistry, pharmacology and toxicity of Arctium lappa L. fruit

ETHNOPHARMACOLOGICAL RELEVANCE

Arctium lappa L., is a biennial plant that grows around the Eurasia. Many parts of Arctium lappa L. (roots, leaves and fruits, etc.) are medically used in different countries. Arctium lappa L. fruit, also called Arctii Fructus, is traditionally applied to dispel wind-heat, ventilate lung to promote eruption, remove toxicity substance and relieve sore throat.

THE AIM OF THE REVIEW

The review aims to integrate the botany, ethnopharmacology, quality control, phytochemistry, pharmacology, derivatives and toxicity information of Arctii Fructus, so as to facilitate future research and explore the potential of Arctii Fructus as an agent for treating diseases.

MATERIALS AND METHODS

Related knowledge about Arctii Fructus were acquired from Science Direct, GeenMedical, PubMed, China National Knowledge Infrastructure (CNKI), Web of Science, Pharmacopoeia of the People's Republic of China, Doctoral and Master's thesis, ancient books, etc. RESULTS: Arctii Fructus as an herb used for medicine and food was pervasively distributed and applicated around the world. It was traditionally used to treat anemopyretic cold, dyspnea and cough, sore throat, etc. To date, more than 200 compounds have been isolated and identified from Arctii Fructus. It contained lignans, phenolic acids and fatty acids, terpenoids, volatile oils and others. Lignans, especially arctigenin and arctiin, had the extensive pharmacological effects such as anti-cancer, antiviral, anti-inflammatory activities. The ester derivatives of arctigenin had the anti-cancer, anti-Alzheimer's disease and immunity enhancing effects. Although Arctii Fructus extract had no toxicity, arctigenin was toxic at a certain dose. The alleviating effects of Arctii Fructus on chronic inflammation and ageing have been demonstrated by clinical studies.

CONCLUSION

Arctii Fructus is regarded as a worthy herb with many chemical components and various pharmacological effects. Several traditional applications have been supported by modern pharmacological research. However, their action mechanisms need to be further studied. Although many chemical components were isolated from Arctii Fructus, the current research mainly focused on lignans, especially arctiin and arctigenin. Therefore, it is very important to deeply clarify the pharmacological activities and action mechanism of the compounds and make full medicinal use of the resources of Arctii Fructus.

The therapeutic potential of arctigenin against multiple human diseases: A mechanistic review

BACKGROUND

Arctigenin (ATG), a dibenzyl butyrolactone lignan compound, is one of the major bioactive components from the medicinal plant Arctium lappa. ATG possesses remarkable therapeutic potential against a wide range of human diseases, such as cancers, immune disorders and chronical diseases. The molecular mechanisms behind the biological effects of ATG have been intensively studied.

PURPOSE

This review aims to systematically summarize the updated knowledge of the proteins and signaling pathways behind the curative property of ATG, and further analyze the potential connections between them.

METHOD

SciFinder, Pubmed, Web of Science and Cochrane Library databases were queried for publications reporting the therapeutic properties of ATG. "Arctigenin", "disease", "cancer", "inflammation", "organ damage", "infection", "toxicity" and "pharmacokinetics" were used as the searching titles.

RESULT

625 publications were identified and 95 met the inclusion criteria and exclusion criteria. 42 studies described the molecular mechanisms implicated in ATG treatments. Several proteins including phosphodiesterase subtype 4D (PDE4D), estrogen receptor (ER) β, protein phosphatase 2A (PP2A), phosphoinositide 3-kinase (PI3K) and transmembrane protein 16A (TMEM16A) are targeted by ATG in different settings. The frequently described signaling pathways are TLR4/NF-κB, PI3K/AKT/mTOR, AMP-activated protein kinase (AMPK) and nuclear factor erythroid 2-related factor 2 (Nrf-2) signalings.

CONCLUSION

Inhibition of PI3K/AKT pathway and activation of AMPK signaling play the pivotal roles in the therapeutic effects of ATG. PI3K/AKT and AMPK signaling widely link to other signaling pathways, modulating various biological processes such as anti-inflammation, anti-oxidative stress, anti-fibrosis, anti-ER stress, anti-steatosis and pro-apoptosis, which constitute the curative mechanisms of ATG against multiple human diseases.

Arctigenin: pharmacology, total synthesis, and progress in structure modification

Arctium lappa L. is a prevalent medicinal herb and a health supplement that is commonly used in Asia. Over the last few decades, the bioactive component arctigenin has attracted the attention of researchers because of its anti-inflammatory, antioxidant, immunomodulatory, multiple sclerosis fighting, antitumor, and anti-leukemia properties. After summarising the research and literature on arctigenin, this study outlines the current status of research on pharmacological activity, total synthesis, and structural modification of arctigenin. The purpose of this study is to assist academics in obtaining a more comprehensive understanding of the research progress on arctigenin and to provide constructive suggestions for further investigation of this useful molecule.

FoxO3 restricts liver regeneration by suppressing the proliferation of hepatocytes

Upon injury, the liver is capable of substantial regeneration from the original tissue until an appropriate functional size. The underlying mechanisms controlling the liver regeneration processes are not well elucidated. Previous studies have proposed that the transcription factor FoxO3 is involved in various liver diseases, but its exact role in the regulation of liver regeneration remains largely unclear. To directly test the detailed role of FoxO3 in liver regeneration, both a constitutive Albumin-Cre driver line and adeno-associated virus serotype 8 (AAV8)-Tbg-Cre (AAV-Cre)-injected adult FoxO3^fl/fl mice were subjected to 70% partial hepatectomy (PH). Our data demonstrate that FoxO3 deletion accelerates liver regeneration primarily by limiting polyploidization and promoting the proliferation of hepatocytes during liver regeneration. RNA-seq analysis indicates that FoxO3 deficiency greatly alters the expression of gene sets associated with cell proliferation and apoptosis during liver regeneration. Chromatin immunoprecipitation-PCR (ChIP-PCR) and luciferase reporter assays reveal that FoxO3 promotes the expression of Nox4 but suppresses the expression of Nr4a1 in hepatocytes. AAV8 virus-mediated overexpression of Nox4 and knockdown of Nr4a1 significantly suppressed hepatocyte proliferation and liver regeneration in FoxO3-deficient mice. We demonstrate that FoxO3 negatively controls hepatocyte proliferation through Nox4 upregulation and Nr4a1 downregulation, thereby ensuring appropriate functional regeneration of the liver. Our findings provide novel mechanistic insight into the therapeutic mechanisms of FoxO3 in liver damage and repair.

Effect of miR-183-5p on Cholestatic Liver Fibrosis by Regulating Fork Head Box Protein O1 Expression

Liver fibrosis is a common pathological feature of end-stage liver disease and has no effective treatment. MicroRNAs (miRNAs) have been found to modulate gene expression in liver disease. But the potential role of miRNA in hepatic fibrosis is still unclear. The objective of this research is to study the potential mechanism and biological function of miR-183-5p in liver fibrosis. In this study, we used high-throughput sequencing to find that miR-183-5p is upregulated in human fibrotic liver tissues. In addition, miR-183-5p was upregulated both in rat liver fibrosis tissue induced by bile-duct ligation (BDL) and activated LX-2 cells (human hepatic stellate cell line) according to the result of quantitative real-time PCR (RT-qPCR). Moreover, the inhibition of miR-183-5p alleviated liver fibrosis, decreased the fibrotic biomarker levels in vitro and in vivo, and led toLX-2 cell proliferation inhibition and, apoptosis induction. The result of dual-luciferase assay revealed that miR-183-5p suppressed fork head box protein O1 (FOXO1) expression by binding to its 3'UTR directly. Next, we used lentivirus to overexpress FOXO1 in LX-2 cells, and we found that overexpression of FOXO1 reversed the promotion of miR-183-5p on liver fibrosis, reducing the fibrotic biomarker levels inLX-2 cells, inhibitingLX-2 cell proliferation, and promoting apoptosis. Furthermore, overexpression of FOXO1 prevented the activation of the transforming growth factor (TGF)-β signaling pathway in TGF-β1-induced LX-2 cells according to the result of western blotting. In conclusion, the findings showed thatmiR-183-5p might act as a key regulator of liver fibrosis, and miR-183-5p could promote cholestatic liver fibrosis by inhibiting FOXO1 expression through the TGF-β signaling pathway. Thus, inhibition of miR-183-5pmay be a new way to prevent and improve liver fibrosis.

Research progress on the molecular mechanism of coronary microvascular endothelial cell dysfunction

Coronary microvascular disease is a high-risk factor for many cardiovascular events. However, due to its high concealment and many etiologies, the current understanding of its pathophysiological mechanism is very limited, which greatly limits its clinical diagnosis and treatment. In the process of the occurrence and development of coronary microvascular disease, the damage of coronary microvascular endothelial cell (CMEC) is the core link. CMEC's stress, metabolism, inflammation and other dysfunctions have a causal relationship with coronary microvascular disease, and are also the main features of coronary microvascular disease in the early stage. This article mainly reviews the molecular mechanisms of CMEC damage.

A Network Pharmacology Approach to Explore the Mechanisms of Artemisiae scopariae Herba for the Treatment of Chronic Hepatitis B

Background

As a traditional Chinese medicine, Artemisiae scopariae Herba (ASH) is used to treat various liver diseases. The purpose of this study was to explore the mechanisms of ASH for treating chronic hepatitis B (CHB) using a network pharmacological method.

Methods

Bioactive ingredients and related targets of ASH were obtained from Traditional Chinese Medicine Systems Pharmacology (TCMSP) database. Gene names of targets were extracted from UniProt database. Differentially expressed genes (DEGs) of CHB were obtained from microarray dataset GSE83148. The intersect genes between DEGs and target genes were annotated using clusterProfiler package. The STRING database was used to obtain a network of protein-protein interactions. Cytoscape 3.7.2 was used to construct the “ingredient-gene-pathway” (IGP) network. Molecular docking studies were performed using Autodock vina.

Results

A total of 13 active components were extracted from TCMSP database. Fifteen intersect genes were obtained between 183 target genes and 403 DEGs of GSE83148. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis results showed that ASH against CHB mainly involved in toll-like receptor signaling pathway, cellular senescence, hepatitis B, and chemokine signaling pathway. We screened one hub compound, five core targets, and four key pathways from constructed networks. The docking results indicated the strong binding activity between quercetin and AKT1.

Conclusions

This study provides potential molecular mechanisms of ASH against CHB based on exploration of network pharmacology.

HJC0416 Attenuates Fibrogenesis in Activated Hepatic Stellate Cells via STAT3 and NF-κB Pathways

BACKGROUND

Hepatic fibrosis is wound-healing response that is the result of hepatic stellate cell (HSC) activation and subsequent excess extracellular matrix deposition. HSCs can be activated by a variety of inflammatory stimuli as well as through the signal transducer and activator of transcription 3 (STAT3) pathway. HJC0416 is a novel, orally bioavailable small-molecule inhibitor of STAT3 that was developed by our team using a fragment-based drug design approach. Previously, our team has shown that HJC0416 has antifibrogenic effects in activated HSCs. Recently, increasing evidence suggests that nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) plays an important role in the activation of HSCs. In the present study, we examined the role of NF-κB inhibition of HSC activation by HJC0416.

METHODS

LX-2 (human) and HSC-T6 (rat) cell lines were used. Expression levels of extracellular proteins, NF-κB and STAT3 expression and DNA binding, and inflammatory cytokine levels were determined using western blot, ELISA, and immunofluorescence assay.

RESULTS

HJC0416 decreased cell viability in a dose-dependent manner in both cell lines and arrested the cell cycle at the S phase. Increased apoptosis was seen in LX-2 cells through Yo-Pro-1 and propidium iodide immunofluorescent stating. HJC0416 significantly decreased expression of fibronectin and collagen I as well as markedly decreased α-SMA and laminin. HJC0416 inhibited the STAT3 pathway by decreasing phosphorylation of STAT3, as well as signal transduction pathway activation. Notably, HJC0416 also inhibited the classic and alternative pathways of NF-κB activation. HJC0416 inhibited LPS-induced p65 nuclear translocation and DNA binding, as well as prevented phosphorylation and degradation of inhibitory protein IκBα. HJC0416 also prevented phosphorylation of serine residue 536 on p65.

CONCLUSIONS

HJC0416, an inhibitor of STAT3, was found to have antifibrogenic properties in activated hepatic stellate cell lines. In addition, HJC0416 was found to inhibit the NF-κB pathway. Owing to this double effect, HJC0416 demonstrates promise for in vivo experimentation as an antifibrosis treatment.

FOXO1 and FOXO3a sensitize non-small-cell lung cancer cells to cisplatin-induced apoptosis independent of Bim

Low sensitivity to chemotherapy has been a major challenge in the treatment of non-small-cell lung cancer (NSCLC). It is of great clinical significance to discover its mechanisms to improve cell sensitivity to chemotherapeutic drugs. The forkhead box subfamily O (FOXO) transcriptional factors are downstream factors of the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) pathway and are reported to play pro-apoptotic roles in a variety of cells including NSCLC cells. But their roles and mechanisms in mediating cell response to chemotherapy remain to be discovered. We proposed that FOXO1 and FOXO3a may increase the sensitivity of NSCLC cells to cisplatin. Moreover, we presumed that LY294002, an inhibitor of the PI3K/AKT pathway, may enhance the cytotoxic effects of cisplatin through upregulating FOXO1 and FOXO3a. In the present study, we found that cisplatin initially increased the expressions and nuclear accumulation of FOXO1 and FOXO3a in NSCLC. Knockdown of FOXO1 and FOXO3a significantly decreased the cell sensitivity to cisplatin in vitro and in vivo. Moreover, inhibition of FOXO1 and FOXO3a attenuated cisplatin-induced cell apoptosis independent of Bim, a pro-apoptotic protein downstream of the FOXOs. Moreover, LY294002 synergistically increased the cytotoxic effects of cisplatin. Mechanistically, LY294002 increased the expressions and nuclear accumulation of FOXO1 and FOXO3a. Knockdown of FOXO1 and FOXO3a abrogated the enhancing effect of LY294002 on cisplatin. Taken together, our results suggested that FOXO1 and FOXO3a sensitize NSCLC cells to cisplatin and mediate the enhancing effects of LY294002 on cisplatin.

miR-196b-5p inhibits proliferation of Wharton's jelly umbilical cord stem cells

Human umbilical cord mesenchymal stem cells can be obtained from different parts of the umbilical cord, including Wharton's jelly. Transplantation of Wharton's jelly umbilical cord stem cells (WJCMSCs) is a promising strategy for the treatment of various diseases. However, the molecular mechanisms underlying the proliferation of WJCMSCs are incompletely understood. Here, we report that overexpression of miR‐196b‐5p in WJCMSCs suppresses proliferation and arrests the cell cycle in G0/G1 phase, whereas knockdown of miR‐196b‐5p promotes WJCMSC proliferation and cell‐cycle progression. Moreover, miR‐196b‐5p overexpression resulted in decreased levels of Cyclin A, Cyclin D, Cyclin E and cyclin‐dependent kinases 2 and increased levels of p15^INK4b, whereas miR‐196b‐5p knockdown had the opposite effects. In conclusion, our data suggests that miR‐196b‐5p inhibits WJCMSC proliferation by enhancing G0/G1‐phase arrest.

Arctigenin suppresses fibroblast activity and extracellular matrix deposition in hypertrophic scarring by reducing inflammation and oxidative stress

Hypertrophic scars (HSs) are a progressive fibroproliferation disorder caused by abnormal tissue repair after deep skin injury, and are characterized by continuous activation of fibroblasts and excessive deposition of extracellular matrix. Arctigenin (ATG), a phytomedicine derived from certain plants, displays antifibrotic effects in certain diseases, such as oral submucous fibrosis and peritoneal fibrosis. In the present study, to determine the antifibrotic potential of ATG in HS, a bleomycin (BLM)-induced skin fibrosis murine model was established. C57BL/6 mice were randomly divided into Control group, BLM group and BLM+ATG group. At 1 day post-bleomycin induction, the BLM+ATG group was intraperitoneally injected with 3 mg/kg/day ATG for 28 consecutive days. Pathological changes in the skin tissues were observed by hematoxylin and eosin staining. Collagen content was determined using a Sircol Collagen assay kit. Immunofluorescence staining was performed to detect the expression of TGF-β1 and α-SMA. The expression changes of various factors were detected by reverse transcription-quantitative PCR, western blotting and ELISA. Compared with the BLM group, ATG treatment significantly alleviated skin fibrosis by reducing dermal thickness, collagen content and expression levels of extracellular matrix-related genes (collagen type I α1 chain, collagen type I α2 chain, connective tissue growth factor and plasminogen activator inhibitor-1) in BLM-induced fibrotic skin. ATG also inhibited the transformation of fibroblasts into myofibroblasts in vivo and decreased the expression of TGF-β1 in BLM-induced fibrotic skin. Furthermore, the contents of proinflammatory cytokines, including IL-1β, IL-4, IL-6, TNF-α and monocyte chemoattractant protein-1, were significantly decreased in the BLM+ATG group compared with the BLM group. Redox imbalance and oxidative stress were also reversed by ATG in BLM-induced fibrotic skin, as demonstrated by the upregulation of antioxidants (glutathione and superoxide dismutase) and downregulation of oxidants (malondialdehyde) in the BLM+ATG group compared with the BLM group. Moreover, the results indicated that the antioxidant effect of ATG may occur via activation of the nuclear factor erythroid-2-related factor 2/heme oxygenase-1 signaling pathway. Collectively, the present study indicated that ATG could ameliorate skin fibrosis in a murine model of HS, which was partly mediated by reducing inflammation and oxidative stress. Therefore, ATG may serve as a therapeutic agent for HSs.

Role of phosphatidylinositol 3-kinase signaling pathway in radiation-induced liver injury

Transforming growth factor-β1 (TGF-β1) is one of critical cytokines in radiation-induced liver injury. Hepatic stellate cells (HSC) are activated in the early stage of radiation-induced liver injury. However, it is currently unclear whether phosphatidylinositol 3-kinase (PI3K/Akt) signal pathway is activated in radiation-induced liver injury. Herein, male Sprague-Dawley rats were irradiated with 6 MV X-rays (30 Gy) on the right liver. Next, Hematoxylin and eosin staining, Masson staining, and electron microscopy were performed to examine pathological changes. Immunohistochemistry was performed to assess the expression of TGF-β1, α-SMA, and p-Akt (S473) in liver tissues. In vitro, rat HSC cell line HSC-T6 cells were given different doses of 6 MV X-ray irradiation (10 and 20 Gy) and treated with LY294002. The expression of α-SMA and p-Akt in mRNA and protein levels were measured by reverse transcription-polymerase chain reactioin (RT-PCR) and Western blot. TGF-β1 expression was detected by enzyme-linked immuno sorbent assay (ELISA). After irradiation, the liver tissues showed obvious pathological changes, indicating the establishment of the radiation-induced liver injury. Expression levels of TGF-β1, α-SMA, and p-Akt (S473) protein in liver tissues were significantly increased after irradiation, and this increase was in a time-dependent manner, suggesting the activation of HSC and PI3K/Akt signal pathway. in vitro experiments showed that the TGF-β1 secreted by HSCs, and the expression of Akt and α-SMA at mRNA and protein levels were significantly increased in irradiation groups. However, the expression of TGF-β1, Akt, and α-SMA were significantly decreased in PI3K/Akt signal pathway inhibitor LY294002-treated group. Our results suggest that during radiation-induced liver injury, HSCs are activated by TGF-β1-mediated PI3K/Akt signal pathway.

Tormentic acid inhibits hepatic stellate cells activation via blocking PI3K/Akt/mTOR and NF-κB signalling pathways

The present study was to investigate the inhibitory effect and underlying mechanism of Tormentic acid (TA) on hepatic stellate cells (HSCs). HSC-T6 cells were stimulated with Platelet-derived growth factor-BB (PDGF-BB) and TA, and then cell proliferation, apoptosis, inflammatory factor, and collagen-related indicators were detected. In order to elucidate the potential mechanism, the PI3K/Akt/mTOR and NF-κB signalling pathways were also detected. The results showed that TA treatment markedly inhibited PDGF-BB-stimulated HSC-T6 cell activation, as evidenced by the inhibition of cell proliferation, migration and colony formation, as well as the decreased expression of TGF-β and α-SMA. TA treatment caused a significant increase in the activity of lactate dehydrogenase and significantly promoted cell apoptosis. TA treatment significantly reduced aspartate aminotransferase, alanine aminotransferase and total bilirubin activity. Importantly, TA inhibited the expression of collagen type I and III, alleviating the excessive deposition of extracellular matrix (ECM). Further experiments showed that TA administration significantly inhibited the phosphorylation of PI3K, Akt, FAK and mTOR and the protein expression of P70S6K, indicating the inhibition of the PI3K/Akt/mTOR pathway. Moreover, treatment with TA markedly decreased the phosphorylation of IκBα, NF-κB p65 and IKKα/β, thereby blocking the NF-κB signal transduction. In summary, this study demonstrates that TA significantly inhibits HSC activation and promotes cell apoptosis via the inhibition of the PI3K/Akt/mTOR and NF-κB signalling pathways. SIGNIFICANCE OF THE STUDY: Tormentic acid (TA) could inhibit HSC activation and alleviate collagen-based ECM deposition, suggesting that TA exerted anti-hepatic fibrosis. Further mechanism research revealed that the inhibition of TA on HSC activation might be through blocking the PI3K/Akt/mTOR and NF-κB signalling pathways. These findings provided a new cue to understand the protective effect of TA against liver fibrosis, which may provide a potential nature medicine for the treatment of liver fibrosis.

Skp2 in the ubiquitin-proteasome system: A comprehensive review

The ubiquitin-proteasome system (UPS) is a complex process that regulates protein stability and activity by the sequential actions of E1, E2 and E3 enzymes to influence diverse aspects of eukaryotic cells. However, due to the diversity of proteins in cells, substrate selection is a highly critical part of the process. As a key player in UPS, E3 ubiquitin ligases recruit substrates for ubiquitination specifically. Among them, RING E3 ubiquitin ligases which are the most abundant E3 ubiquitin ligases contribute to diverse cellular processes. The multisubunit cullin-RING ligases (CRLs) are the largest family of RING E3 ubiquitin ligases with tremendous plasticity in substrate specificity and regulate a vast array of cellular functions. The F-box protein Skp2 is a component of CRL1 (the prototype of CRLs) which is expressed in many tissues and participates in multiple cellular functions such as cell proliferation, metabolism, and tumorigenesis by contributing to the ubiquitination and subsequent degradation of several specific tumor suppressors. Most importantly, Skp2 plays a pivotal role in a plethora of cancer-associated signaling pathways. It enhances cell growth, accelerates cell cycle progression, promotes migration and invasion, and inhibits cell apoptosis among others. Hence, targeting Skp2 may represent a novel and attractive strategy for the treatment of different human cancers overexpressing this oncogene. In this review article, we summarized the known roles of Skp2 both in health and disease states in relation to the UPS.

Artesunate promotes the proliferation of neural stem/progenitor cells and alleviates Ischemia-reperfusion Injury through PI3K/Akt/FOXO-3a/p27kip1 signaling pathway

Stroke is one of the leading causes of death worldwide that also result in long-term disability. Endogenous neural stem/progenitor cells (NSPCs) within subventricular (SVZ) and dentate gyrus (DG) zone, stimulated by cerebral infarction, can promote neural function recovery. However, the proliferation of eNSPCs triggered by ischemia is not enough to induce neural repair, which may contribute to the permanent disability in stroke patients. In this study, our results showed that following the treatment with artesunate (ART, 150 mg/kg), the functional recovery was significantly improved, the infarct volume was notably reduced, and the expression of Nestin, a proliferation marker of NSPCs in the infarcted cortex, was also increased. Additionally, the proliferative activity of NSPCs with or without oxygen-glucose deprivation/reperfusion was significantly promoted by ART treatment, and the therapeutic concentration was 0.8 μmol/L (without OGD/R) or 0.4 μmol/L (with OGD/R) in the in vitro model. Furthermore, the effects of ART can be abolished by the treatment of PI3K inhibitor wortmannin. The expression levels of related molecules in PI3K/Akt/FOXO-3a/p27^kip1 signaling pathway (p-AKT, p-FOXO-3a, p27^kip1) were examined using western blotting. The results suggested ART could inhibit the transcriptional function of FOXO-3a by inducing its phosphorylation, subsequently downregulating p27^kip1 and enhancing neural stem cell proliferation in the infarcted cortex via PI3K/AKT signaling, further alleviating ischemia-reperfusion injury after ischemic stroke.

Leptin-derived peptides block leptin-induced proliferation by reducing expression of pro-inflammatory genes in hepatocellular carcinoma cells

The obesity-regulated gene, leptin, is essential for diet. Leptin resistance causes obesity and related diseases. Certain types of diet are able to decrease leptin resistance. However, leptin has been shown to be correlated with inflammation and stimulate proliferation of various cancers. Two synthetic leptin derivatives (mimetics), OB3 and [D-Leu-4]-OB3, show more effective than leptin in reducing obesity and diabetes in mouse models. OB3 inhibits leptin-induced proliferation in ovarian cancer cells. However, effects of these mimetics in hepatocellular carcinoma (HCC) have not been investigated. In the present study, we examined the effects of OB3 and [D-Leu-4]-OB3 on cell proliferation and gene expressions in human HCC cell cultures. In contrast to what was reported for leptin, OB3 and [D-Leu-4]-OB3 reduced cell proliferation in hepatomas. Both OB3 and [D-Leu-4]-OB3 stimulated expression of pro-apoptotic genes. Both compounds also inhibited expressions of pro-inflammatory, proliferative and metastatic genes and PD-L1 expression. In combination with leptin, OB3 inhibited leptin-induced cell proliferation and expressions of pro-inflammation-, and proliferation-related genes. Furthermore, the OB3 peptide inhibited phosphoinositide 3-kinase (PI3K) activation which is essential for leptin-induced proliferation in HCC. These results indicate that OB3 and [D-Leu-4]-OB3 may have the potential to reduce leptin-related inflammation and proliferation in HCC cells.

Overexpressed vascular endothelial growth factor in adipose derived stem cells attenuates fibroblasts and skin injuries by ultraviolet radiation

Adipose-derived stem cells (ADSCs) and vascular endothelial growth factor (VEGF) contribute to the healing of wound. The purpose of the present study was to investigate the role of VEGF produced by ADSCs in the protection of fibroblasts and skin of mice from ultraviolet (UV) radiation. ADSCs and fibroblasts were extracted from adipose and skin on the abdomen of mice by enzyme digestion methods. ADSCs surface markers were detected using flow cytometry, and immunofluorescence was used to identify fibroblasts. The expression of VEGF in modified ADSCs with lentivirus was determined. Fibroblasts were injured by UV radiation and co-cultured with ADSCs carrying overexpressed VEGF or normal VEGF. Cell cycle was assessed by flow cytometry. Mice were treated with UV radiation dorsally and injected with ADSCs containing overexpressed VEGF or normal VEGF. mRNA and protein levels of cell senescence-related genes were measured by qPCR and western blot. It was found that ADSCs with overexpressed VEGF not only promoted the effect of ADSCs on down-regulating senescence-associated (SA)-β-Gal, p21 and matrix metalloproteinase (MMP)-1, the healing of wound injured by UV radiation and up-regulating collagen I expression in fibroblasts and wound, but also on inhibiting cell cycle arrest in fibroblasts injured by UV radiation and preventing the skin from photoaging caused by UV radiation. VEGF expression in ADSCs played a key role in protecting skin fibroblasts from ageing, which further allowed the skin to resist photoaging, thereby promoting the recovery of wound injured by UV radiation.

Network Pharmacology-Based Prediction of the Active Compounds, Potential Targets, and Signaling Pathways Involved in Danshiliuhao Granule for Treatment of Liver Fibrosis

This study aims to predict the active ingredients, potential targets, signaling pathways and investigate the “ingredient-target-pathway” mechanisms involved in the pharmacological action of Danshiliuhao Granule (DSLHG) on liver fibrosis. Pharmacodynamics studies on rats with liver fibrosis showed that DSLHG generated an obvious anti-liver fibrosis action. On this basis, we explored the possible mechanisms underlying its antifibrosis effect using network pharmacology approach. Information about compounds of herbs in DSLHG was collected from TCMSP public database and literature. Furthermore, the oral bioavailability (OB) and drug-likeness (DL) were screened according to ADME features. Compounds with OB≥30% and DL≥0.18 were selected as active ingredients. Then, the potential targets of the active compounds were predicted by pharmacophore mapping approach and mapped with the target genes of the specific disease. The compound-target network and Protein-Protein Interaction (PPI) network were built by Cytoscape software. The core targets were selected by degree values. Furthermore, GO biological process analysis and KEGG pathway enrichment analysis were carried out to investigate the possible mechanisms involved in the anti-hepatic fibrosis effect of DSLHG. The predicted results showed that there were 108 main active components in the DSLHG formula. Moreover, there were 192 potential targets regulated by DSLHG, of which 86 were related to liver fibrosis, including AKT1, EGFR, and IGF1R. Mechanistically, the anti-liver fibrosis effect of DSLHG was exerted by interfering with 47 signaling pathways, such as PI3K-Akt, FoxO signaling pathway, and Ras signaling pathway. Network analysis showed that DSLHG could generate the antifibrosis action by affecting multiple targets and multiple pathways, which reflects the multicomponent, multitarget, and multichannel characteristics of traditional Chinese medicine and provides novel basis to clarify the mechanisms of anti-liver fibrosis of DSLHG.

FOXK transcription factors: Regulation and critical role in cancer

Growing evidence suggests that alterations of gene expression including expression and activities of transcription factors are closely associated with carcinogenesis. Forkhead Box Class K (FOXK) proteins, FOXK1 and FOXK2, are a family of evolutionarily conserved transcriptional factors, which have recently been recognized as key transcriptional regulators involved in many types of cancer. Members of the FOXK family mediate a wide spectrum of biological processes, including cell proliferation, differentiation, apoptosis, autophagy, cell cycle progression, DNA damage and tumorigenesis. Therefore, the deregulation of FOXKs can affect the cell fate and they promote tumorigenesis as well as cancer progression. The mechanisms of FOXKs regulation including post-translational modifications (PTMs), microRNAs (miRNAs) and protein-protein interactions are well demonstrated. However, the detailed mechanisms of FOXKs activation and deregulation in cancer progression are still inconclusive. In this review, we summarize the regulatory mechanisms of FOXKs expression and activity, and their role in the development and progression of cancer. We have discussed whether FOXKs act as tumor suppressors/oncoproteins in tumor cells and their therapeutic applications in malignant diseases are also discussed. This review may assist in designing experimental studies involving FOXKs and it would strength the therapeutic potential of FOXKs as targets for cancers.

The histone demethylase Kdm4 suppresses activation of hepatic stellate cell by inducing MiR-29 transcription

One of the hallmark events during liver fibrosis is the transition of quiescent hepatic stellate cells (HSC) into activated myofibroblasts, which are responsible for the production and deposition of pro-fibrogenic proteins. The epigenetic mechanism underlying HSC trans-differentiation is not fully understood. In the present study we investigated the contribution of histone H3K9 demethylase KDM4 in this process. We report that expression levels of KDM4 were down-regulated during HSC activation paralleling the up-regulation of alpha smooth muscle cell actin (Acta2), a marker of mature myofibroblast. Furthermore, HSCs isolated from mice induced to develop liver fibrosis exhibit lowered KDM4 expression compared to the control mice. In accordance, KDM4 depletion with siRNA accelerated HSC activation. Of interest, the loss of KDM4 was mirrored by the repression of miR-29, an antagonist of liver fibrosis, during HSC activation both in vitro and in vivo. KDM4 knockdown resulted in the down-regulation of miR-29 expression. Mechanistically, the sequence-specific transcription factor SREBP2 interacted with KDM4 to activate miR-29 transcription. In conclusion, our data delineate a novel epigenetic mechanism underlying HSC activation. Targeting this axis may yield potential therapeutics against liver fibrosis.

Arctigenin Reduces Myofibroblast Activities in Oral Submucous Fibrosis by LINC00974 Inhibition

Oral submucous fibrosis (OSF) is an oral precancerous condition associated with the habit of areca nut chewing and the TGF-β pathway. Currently, there is no curative treatment to completely heal OSF, and it is imperative to alleviate patients’ symptoms and prevent it from undergoing malignant transformation. Arctigenin, a lignan extracted from Arctium lappa, has been reported to have a variety of pharmacological activities, including anti-fibrosis. In the present study, we examined the effect of arctigenin on the cell proliferation of buccal mucosal fibroblasts (BMFs) and fibrotic BMFs (fBMFs), followed by assessment of myofibroblast activities. We found that arctigenin was able to abolish the arecoline-induced collagen gel contractility, migration, invasion, and wound healing capacities of BMFs and downregulate the myofibroblast characteristics of fBMFs in a dose-dependent manner. Most importantly, the production of TGF-β in fBMFs was reduced after exposure to arctigenin, along with the suppression of p-Smad2, α-smooth muscle actin, and type I collagen A1. In addition, arctigenin was shown to diminish the expression of LINC00974, which has been proven to activate TGF-β/Smad signaling for oral fibrogenesis. Taken together, we demonstrated that arctigenin may act as a suitable adjunct therapy for OSF.

Crosstalk between Phosphoinositide 3-kinase/Akt signaling pathway with DNA damage response and oxidative stress in cancer

The phosphatidylinositol 3-kinases (PI3K)/Akt signaling pathway is one of the well-characterized and most important signaling pathways activated in response to DNA damage. This review discusses the most recent discoveries on the involvement of PI3K/Akt signaling pathway in cancer development, as well as stimulation of some important signaling networks involved in the maintenance of cellular homeostasis upon DNA damage, with an exploration of how PI3K/Akt signaling pathway contributes to the regulation of modulators and effectors underlying DNA damage response, the intricate, protein-based signal transduction network, which decides between cell cycle arrest, DNA repair, and apoptosis, the elimination of irreparably damaged cells to maintain homeostasis. The review continues by looking at the interplay between cell cycle checkpoints, checking the repair of damage inflicted to the DNA before entering DNA replication to facilitate DNA synthesis, and PI3K/Akt signaling pathway. We then investigate the challenges the cells overcome to ameliorate damages induced by oxidative activities, for example, the recruitment of many pathways and factors to maintain integrity and hemostasis. Finally, the review provides a discussion of how cells use the PI3K/Akt signaling pathway to regulate the balance between these networks.

Luteolin-Mediated Inhibition of Hepatic Stellate Cell Activation via Suppression of the STAT3 Pathway

Hepatic stellate cell (HSC) activation is responsible for hepatic fibrogenesis and is associated with an overexpression of transcription 3 (STAT3). Luteolin, a common dietary flavonoid with potent anti-inflammatory properties, has previously demonstrated antifibrogenic properties in HSCs but the mechanism has not been fully elucidated. Activated human and rat hepatic stellate cell lines LX-2 and HSC-T6 were used to study the effects of luteolin on HSCs. Cellular proteins were determined by western blot and immunofluorescence. Cell proliferation was assessed with Alamar Blue assay. Luteolin significantly decreased LX-2 and HSC-T6 cell viability in a time-and-dose-dependent manner, as well as decreased HSC end-products α-smooth muscle actin (α-SMA), collagen I, and fibronectin. Luteolin decreased levels of total and phosphorylated STAT3, suppressed STAT3 nuclear translocation and transcriptional activity, and attenuated expression of STAT3-regulated proteins c-myc and cyclin D1. STAT3 specific inhibitors stattic and SH-4-54 demonstrated similar effects on HSC viability and α-SMA production. In LX-2 and HSC-T6 cells, luteolin demonstrates a potent ability to inhibit hepatic fibrogenesis via suppression of the STAT3 pathway. These results further elucidate the mechanism of luteolin as well as the effect of the STAT3 pathway on HSC activation.

Recombinant SjP40 protein enhances p27 promoter expression in hepatic stellate cells via an E2F1-dependent mechanism

The p27 protein plays a critical role in cell cycle arrest. Our previous studies have demonstrated that recombinant P40 protein from Schistosoma japonicum (rSjP40) could induce G1 phase arrest of cell cycle. We, therefore, attempted to observe the effect of rSjP40 on p27 promoter activity in LX-2 cells and to explore its potential mechanisms in this study. Using both Western blot and dual-luciferase reporter assay, we demonstrated that rSjP40 could enhance the expression of p27 in LX-2 cells. Results obtained using truncated fragments of p27 promoter showed that rSjP40 increased p27 promoter activity in LX-2 cells, mainly via some transcription factors that bind to the -1740/-873 region of p27 promoter. Further studies confirmed that the enhancement of p27 promoter activity induced by rSjP40 was related to E2F1 in LX-2 cells. Transfection of siRNA of E2F1 could also restore the effect of rSjP40 on expression of p27 and partially on α-SMA. Therefore, our study provided further insights into the mechanism by which rSjP40 induces LX-2 cell cycle arrest at G1 phase and inhibits HSC activation. Our results provide basis for future study of the blocking effect of rSjP40 in liver fibrosis.

Arctigenin protects against liver injury from acute hepatitis by suppressing immune cells in mice

As a phenylpropanoid and dibenzylbutyrolactone lignan present in medical plants, such as those used in traditional Chinese herbal medicine, including Arctium lappa (Niubang), arctigenin exhibits antimicrobial, anti-inflammatory, and anticancer activities. In this study, we investigated the protective role of arctigenin in Concanavalin A (ConA)-induced acute hepatitis in mice. Arctigenin remarkably reduced the congestion and necroinflammation of livers, and improved hepatic function (ALT and AST) in ConA-induced acute hepatitis in vivo. The infiltration of CD4 T, NKT and macrophages into the livers was found to be reduced with arctigenin treatment. Arctigenin suppressed ConA-induced T lymphocyte proliferations that might have resulted from enhanced IL-10 production by macrophages and CD4 T cells. These results suggested that arctigenin could be a powerful drug candidate for acute hepatitis through immune suppression.

Arctigenin Inhibits Liver Cancer Tumorigenesis by Inhibiting Gankyrin Expression via C/EBPα and PPARα

Burdock (Arctium lappa) is a popular vegetable in China and Japan that is consumed for its general health benefits. The principal active component of burdock is arctigenin, which shows a range of bioactivities in vivo and in vitro. Here, we investigated the potential anti-tumor effects of arctigenin using two human hepatocellular carcinoma (HCC) cell lines, HepG2 and Hep3B, and sought to elucidate its potential mechanisms of action. Our results showed that arctigenin treatment inhibited cell growth in both HepG2 and Hep3B cell lines (IC₅₀ of 4.74 nM for HepG2 cells, and of 59.27 nM for Hep3B cells). In addition, migration, invasion, and colony formation by HepG2 cells were significantly inhibited by arctigenin. By contrast, treatment of Hep3B cells with arctigenin did not alter these parameters. Arctigenin also significantly reduced the levels of gankyrin mRNA and protein in HepG2 cells, but not in Hep3B cells. A luciferase assay indicated that arctigenin targeted the -450 to -400 region of the gankyrin promoter. This region is also the potential binding site for both C/EBPα and PPARα, as predicted and confirmed by an online software analysis and ChIP assay. Additionally, a co-immunoprecipitation (Co-IP) assay showed that binding between C/EBPα and PPARα was increased in the presence of arctigenin. However, arctigenin did not increase the expression of C/EBPα or PPARα protein. A binding screening assay and liquid chromatography-mass spectrometry (LC-MS) were performed to identify the mechanisms by which arctigenin regulates gankyrin expression. The results suggested that arctigenin could directly increase C/EBPα binding to the gankyrin promoter (-432 to -422 region), but did not affect PPARα binding. Expression of gankyrin, C/EBPα, and PPARα were analyzed in tumor tissues of patients using real-time PCR. Both C/EBPα and PPARα showed negative correlations with gankyrin. In tumor-bearing mice, arctigenin had a significant inhibitory effect on HCC growth. In conclusion, our results suggested that arctigenin could inhibit liver cancer growth by directly recruiting C/EBPα to the gankyrin promoter. PPARα subsequently bound to C/EBPα, and both had a negative regulatory effect on gankyrin expression. This study has identified a new mechanism of action of arctigenin against liver cancer growth.

The PI3K/Akt/FOXO3a pathway regulates regeneration following spinal cord injury in adult rats through TNF-α and p27kip1 expression

The aim of the present study was to elucidate the expression and role of the phosphatidylinositol 3‑kinase (PI3K)/Akt/forkhead box O3 (FOXO3a) pathway in the regeneration of the spinal cord following spinal cord injury (SCI), and its regulatory effect on tumor necrosis factor (TNF)-α and cyclin-dependent kinase inhibitor 1B (p27kip1) expression. Firstly, in a Sprague-Dawley rat model of SCI, western blot analysis revealed that the protein levels of PI3K, phosphorylated Akt and FOXO3a were markedly inhibited compared with those in the sham control group. In vitro experiments were also conducted, in which primary dissociated cultures of rat dorsal spinal cord cells were induced with lipopolysaccharide (LPS; 4 µg/ml). The downregulation of PI3K using LY294002 markedly suppressed cell viability, reduced the protein levels of FOXO3a and p27kip1, and increased TNF-α protein production in the LPS-induced spinal cord cells. In addition, when the LPS-induced spinal cord cells were infected with FOXO3a adenoviral vectors, the overexpression of FOXO3 markedly promoted cell proliferation, activated p27kip1 protein levels and inhibited TNF-α protein production in the spinal cord cells. These results suggest that the PI3K/Akt/FOXO3a pathway regulates regeneration following SCI in adult rats via its modulatory effects on TNF-α and p27kip1 expression.

Regulation of Akt/FoxO3a/Skp2 Axis Is Critically Involved in Berberine-Induced Cell Cycle Arrest in Hepatocellular Carcinoma Cells

The maintenance of ordinal cell cycle phases is a critical biological process in cancer genesis, which is a crucial target for anti-cancer drugs. As an important natural isoquinoline alkaloid from Chinese herbal medicine, Berberine (BBR) has been reported to possess anti-cancer potentiality to induce cell cycle arrest in hepatocellular carcinoma cells (HCC). However, the underlying mechanism remains to be elucidated. In our present study, G0/G1 phase cell cycle arrest was observed in berberine-treated Huh-7 and HepG2 cells. Mechanically, we observed that BBR could deactivate the Akt pathway, which consequently suppressed the S-phase kinase-associated protein 2 (Skp2) expression and enhanced the expression and translocation of Forkhead box O3a (FoxO3a) into nucleus. The translocated FoxO3a on one hand could directly promote the transcription of cyclin-dependent kinase inhibitors (CDKIs) p21^Cip1 and p27^Kip1, on the other hand, it could repress Skp2 expression, both of which lead to up-regulation of p21^Cip1 and p27^Kip1, causing G0/G1 phase cell cycle arrest in HCC. In conclusion, BBR promotes the expression of CDKIs p21^Cip1 and p27^Kip1 via regulating the Akt/FoxO3a/Skp2 axis and further induces HCC G0/G1 phase cell cycle arrest. This research uncovered a new mechanism of an anti-cancer effect of BBR.

FOXO1/3: Potential suppressors of fibrosis

Fibrosis is a universally age-related disease that involves nearly all organs. It is typically initiated by organic injury and eventually results in organ failure. There are still few effective therapeutic strategy targets for fibrogenesis. Forkhead box proteins O1 and O3 (FOXO1/3) have been shown to have favorable inhibitory effects on fibroblast activation and subsequent extracellular matrix production and can ameliorate fibrosis levels in numerous organs, including the heart, liver, lung, and kidney; they are therefore promising targets for anti-fibrosis therapy. Moreover, we can develop appropriate strategies to make the best use of FOXO1/3's anti-fibrosis properties. The information reviewed here should be significant for understanding the roles of FOXO1/3 in fibrosis and should contribute to the design of further studies related to FOXO1/3 and the fibrotic response and shed light on a potential treatment for fibrosis.

Relationship between mTOR signaling pathway and hepatic stellate cells function

The activation of hepatic stellate cells (HSCs) is generally considered to be the central link in the formation of hepatic fibrosis. Various factors can regulate the function of HSCs through multiple signaling pathways, of which the mammalian target of rapamycin (mTOR) signaling pathway is especially important. Elucidating the relationship between the mTOR signaling pathway and the proliferation, apoptosis, autophagy, and senescence of HSCs can provide new therapeutic targets and methods for the clinical treatment of hepatic fibrosis. This paper discusses the relationship between the mTOR signaling pathway and the function of HSCs.

Role of growth factor receptor-bound 2 in CCl4-induced hepatic fibrosis

BACKGROUND

Growth Factor Receptor-bound 2 (GRB2) plays a crucial role in regulation of cellular function including proliferation and differentiation, and we previously identified GRB2 as promoting HSCs (HSCs) proliferation. However, the underlying mechanisms that are involving in the regulation of GRB2 in hepatic fibrogenesis remain unknown.

METHODS

In the present study, we tested the function of GRB2 in hepatic fibrosis. Hepatic fibrosis was induced by subcutaneous CCl₄ administration at a dose of 3mL/kg in rats. The rat HSC cell line HSC-T6 were cultured for proliferation investigation by CCK-8 and BrdU incorporation method. The levels of GRB2, HMGB1, PI3K/AKT, COL1A1 and α-SMA were analyzed by western blot or real-time PCR.

RESULTS

showed that the expression of GRB2 and HMGB1 was obviously increased in liver tissues of hepatic fibrosis rats accompanied by up-regulation of COL1A1 and α-SMA. In cultured HSCs, application of exogenous HMGB1 induced cell proliferation and cell proliferation rate concomitantly with up-regulation of GRB2 expression and PI3K/AKT phosphorylation. The effects of HMGB1-induced proliferation of HSCs and up-regulation of COL1A1 and α-SMA were abolished by GRB2 siRNA. HMGB1-induced proliferation of HSCs and up-regulation of COL1A1 and α-SMA was reversed in the presence of LY294002, an inhibitor of PI3K inhibitor.

CONCLUSIONS

These findings suggest that GRB2 plays an important role in CCl₄-induced hepatic fibrosis by regulating HSCs' function, and up-regulation of GRB2 induced by HMGB1 is mediated via the PI3K/AKT pathway.

Inhibitory effects of delphinidin on the proliferation of ovarian cancer cells via PI3K/AKT and ERK 1/2 MAPK signal transduction

Delphinidin is a member of the anthocyanidin family and is a natural pigment in red cabbage, berries, sweet potatoes and grapes. It possesses nutraceutical properties against various chronic diseases and types of cancer. However, little is known about its preventative effects on epithelial ovarian cancer, a disease that is associated with a low survival rate, a poor prognosis and a high rate of recurrence. The results of the present study demonstrated that the proliferation of SKOV3 cells decreased in a dose-dependent manner in response to treatment with delphinidin, and the phosphorylation of carcinogenic protein kinases associated with the progression of epithelial ovarian cancer was affected by delphinidin treatment. The levels of phosphorylated protein kinase B (AKT), ribosomal protein S6 kinase β-1 (P70S6K), ribosomal protein S (S6), extracellular signal-regulated kinase (ERK)1/2 and p38 were suppressed by increasing concentrations of delphinidin. Furthermore, the combination of certain pharmacological inhibitors, including phosphoinositide 3-kinase (PI3K; LY294002), ERK1/2 (U0126) and delphinidin significantly reduced the proliferation of SKOV3 cells and the phosphorylation of each of those target proteins. In addition, delphinidin treatment exerted anti-proliferative effects on paclitaxel-resistant SKOV3 cells, compared with treatment with paclitaxel alone. These results indicate that delphinidin inhibits the proliferation of SKOV3 cells through inactivation of PI3K/AKT and ERK1/2 mitogen-activated protein kinase signaling cascades, and that this cell signaling pathway may be a pivotal therapeutic target for the prevention of epithelial ovarian cancer, including paclitaxel-resistant ovarian cancer.

Egg antigen p40 of Schistosoma japonicum promotes senescence in activated hepatic stellate cells via SKP2/P27 signaling pathway

Schistosomiasis is characterized by egg deposition, granulomatous inflammatory reaction and then subsequent hepatic fibrosis formation. Activated HSCs are regarded as the main effector cells in the progression of liver fibrosis and induction of senescence in hepatic stellate cells (HSCs) is vital to the reversion of hepatic fibrosis. Our previous work has showed that S. japonicum egg antigen p40 (Sjp40) could promote HSCs senescence via a STAT3/p53/p21 mechanism. In this paper, the major aim was to explore whether there are other signaling pathways in the process of Sjp40-induced HSCs aging and the underlying effect of SKP2/P27 signal pathway in this procedure. We observed the Sjp40-induced decrease of α-SMA and the senescence of LX-2 cells, and Sjp40 could upregulate P27 and downregulate the protein level of SKP2. The senescence induced by Sjp40 might be reversed in LX-2 cells that treated with P27-specific siRNA or with SKP2-special over-expression plasmid. In addition, we also demonstrated that the decreased expression of P-Rb and α-SMA induced by Sjp40 were partly restored by SKP2-overexpression. These data suggest that Sjp40 might inhibit HSCs activation by promoting cellular senescence via SKP2/P27 signaling pathway, which put forward novel mechanism in the treatment of liver fibrosis.

Wharton's Jelly Mesenchymal Stem Cells Protect the Immature Brain in Rats and Modulate Cell Fate

The development of a mammalian brain is a complex and long-lasting process. Not surprisingly, preterm birth is the leading cause of death in newborns and children. Advances in perinatal care reduced mortality, but morbidity still represents a major burden. New therapeutic approaches are thus desperately needed. Given that mesenchymal stem/stromal cells (MSCs) emerged as a promising candidate for cell therapy, we transplanted MSCs derived from the Wharton's Jelly (WJ-MSCs) to reduce the burden of immature brain injury in a murine animal model. WJ-MSCs transplantation resulted in protective activity characterized by reduced myelin loss and astroglial activation. WJ-MSCs improved locomotor behavior as well. To address the underlying mechanisms, we tested the key regulators of responses to DNA-damaging agents, such as cyclic AMP-dependent protein kinase/calcium-dependent protein kinase (PKA/PKC), cyclin-dependent kinase (CDK), ataxia-telangiectasia-mutated/ATM- and Rad3-related (ATM/ATR) substrates, protein kinase B (Akt), and 14-3-3 binding protein partners. We characterized WJ-MSCs using a specific profiler polymerase chain reaction array. We provide evidence that WJ-MSCs target pivotal regulators of the cell fate such as CDK/14-3-3/Akt signaling. We identified leukemia inhibitory factor as a potential candidate of WJ-MSCs' induced modifications as well. We hypothesize that WJ-MSCs may exert adaptive responses depending on the type of injury they are facing, making them prominent candidates for cell therapy in perinatal injuries.

Integrated in silico and experimental methods revealed that Arctigenin inhibited angiogenesis and HCT116 cell migration and invasion through regulating the H1F4A and Wnt/β-catenin pathway

Arctigenin (ARG) has been previously reported to exert diverse biological activities including anti-proliferation, anti-inflammatory, and antiviral, etc. In the current study, the anti-metastasis and anti-angiogenesis activities of ARG were investigated. To further understand how ARG played these bioactivities, proteomic approaches were used to profile the proteome changes in response to ARG treatment using 2DE-MS/MS. Using these approaches, a total of 50 differentially expressed proteins were identified and clustered. Bioinformatics analysis suggested that multiple signalling pathways were involved. Moreover, ARG induced anti-metastatic and anti-angiogenesis activities were mainly accompanied by a deactivation of the Wnt/β-catenin pathway in HCT116 cells.