Ca2+ signalling plays a role in celastrol-mediated suppression of synovial fibroblasts of rheumatoid arthritis patients and experimental arthritis in rats

BACKGROUND AND PURPOSE

Celastrol exhibits anti-arthritic effects in rheumatoid arthritis (RA), but the role of celastrol-mediated Ca2+ mobilization in treatment of RA remains undefined. Here, we describe a regulatory role for celastrol-induced Ca2+ signalling in synovial fibroblasts of RA patients and adjuvant-induced arthritis (AIA) in rats.

EXPERIMENTAL APPROACH

We used computational docking, Ca2+ dynamics and functional assays to study the sarcoplasmic/endoplasmic reticulum Ca2+ ATPase pump (SERCA). In rheumatoid arthritis synovial fibroblasts (RASFs)/rheumatoid arthritis fibroblast-like synoviocytes (RAFLS), mechanisms of Ca2+ -mediated autophagy were analysed by histological, immunohistochemical and flow cytometric techniques. Anti-arthritic effects of celastrol, autophagy induction, and growth rate of synovial fibroblasts in AIA rats were monitored by microCT and immunofluorescence staining. mRNA from joint tissues of AIA rats was isolated for transcriptional analysis of inflammatory genes, using siRNA methods to study calmodulin, calpains, and calcineurin.

KEY RESULTS

Celastrol inhibited SERCA to induce autophagy-dependent cytotoxicity in RASFs/RAFLS via Ca2+ /calmodulin-dependent kinase kinase-β-AMP-activated protein kinase-mTOR pathway and repressed arthritis symptoms in AIA rats. BAPTA/AM hampered the in vitro and in vivo effectiveness of celastrol. Inflammatory- and autoimmunity-associated genes down-regulated by celastrol in joint tissues of AIA rat were restored by BAPTA/AM. Knockdown of calmodulin, calpains, and calcineurin in RAFLS confirmed the role of Ca2+ in celastrol-regulated gene expression.

CONCLUSION AND IMPLICATIONS

Celastrol triggered Ca2+ signalling to induce autophagic cell death in RASFs/RAFLS and ameliorated arthritis in AIA rats mediated by calcium-dependent/-binding proteins facilitating the exploitation of anti-arthritic drugs based on manipulation of Ca2+ signalling.

Consumption of Sugar-Sweetened Beverages Has a Dose-Dependent Effect on the Risk of Non-Alcoholic Fatty Liver Disease: An Updated Systematic Review and Dose-Response Meta-Analysis

Background: Non-alcoholic fatty liver disease (NAFLD) is a serious health problem, but the dose-response relationship between sugar-sweetened beverages (SSBs) and NAFLD remains uncertain. Methods: A systematic review and dose-response meta-analysis were conducted following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Review Manager 5.3 and Stata 14.0 were used to combine trials and analyze data. The dose-response meta-analysis was performed by non-linear trend regression. Results: Twelve studies recruiting a total of 35,705 participants were included. The results showed that the consumption of SSBs was associated with 1.39-fold increased odds of NAFLD (95% CI: 1.29-1.50, p < 0.00001). The risk of NAFLD rose with an increased consumption of SSBs, while the consumptions of low doses (<1 cup/week), middle doses (1-6 cups/week) and high doses (≥7 cups/week) of SSBs increased the relative risk of NAFLD by 14%, 26% and 53%, respectively (p = 0.01, p < 0.00001, p = 0.03, respectively). Conclusions: This study demonstrates that consumers of SSBs are at significantly increased risk of NAFLD, and the consumption of SSBs has a dose-dependent effect on the risk of NAFLD. The findings of this study strengthen the evidence base for healthy dietary patterns and are meaningful for the primary prevention of NAFLD.

Mitochondria-Mediated Pathogenesis and Therapeutics for Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) has become a worldwide epidemic over the last decade. Remarkable progress has been made in understanding the pathogenesis of NAFLD and, subsequently, in developing medications to treat this disease. Although the mechanisms of NAFLD are complex and multifactorial, accumulating and emerging evidence indicates that mitochondria play a critical role in the pathogenesis and progression of NAFLD. Pharmacologic therapies acting on mitochondria may therefore pave the way to novel strategies for the prevention and protection against NAFLD. This review focuses on new insights into the role of hepatic mitochondrial dysfunction in NAFLD, and summarizes recent studies on mitochondria-centric therapies for NAFLD utilizing new medications or repurposing of currently available drugs. Although some studies presented may feature controversial results or are still in lack of clinical verification, it is undoubted that medications that may spare the mitochondria from multiple levels of damage are highly promising, and have begun to be used with some degree of success.

Phytotherapy using blueberry leaf polyphenols to alleviate non-alcoholic fatty liver disease through improving mitochondrial function and oxidative defense

BACKGROUND

Since non-alcoholic fatty liver disease (NAFLD) pathogenesis is multi-factorial, pharmacotherapy with a specific target commonly exhibits limited efficacy. Phytotherapy, whose therapeutic efficacy is based on the combined action of several active compounds, offers new treatment opportunity for NAFLD. As a representative, many natural polyphenols could be utilized in phytotherapy for NAFLD.

PURPOSE

In present work, we aimed to investigate the therapeutic effects and underlying mechanism of polyphenols in blueberry leaves (PBL) on NAFLD from a mitochondria-centric perspective since mitochondrial dysfunction could play a dominant role in NAFLD.

METHODS

Identification and quantification of PBL were performed using liquid chromatography coupled with tandem mass spectrometry. The beneficial effects, especially improving mitochondrial function, and potential mechanism of PBL on NAFLD were studied by in vitro and in vivo study.

RESULTS

Polyphenols were abundant in blueberry leaves making it advantaged in NAFLD phytotherapy. PBL effectively alleviated hepatic steatosis, oxidative stress and inflammation as indicated by both in vitro and in vivo study. Furthermore, PBL mediated improvement of mitochondrial dysfunction and antioxidant capability through activation of AMPK/PGC-1α/SIRT3 signaling axis.

CONCLUSION

Considering that mitochondrial dysfunction takes precedence over hepatic steatosis and induces NAFLD development, we conclude that PBL improve mitochondrial dysfunction and oxidative defense, subsequently alleviate hepatic steatosis, oxidative stress and inflammation, and eventually alleviate NAFLD.

Method for Quantification of Ribonucleotides and Deoxyribonucleotides in Human Cells Using (Trimethylsilyl)diazomethane Derivatization Followed by Liquid Chromatography-Tandem Mass Spectrometry

Investigation into intracellular ribonucleotides (RNs) and deoxyribonucleotides (dRNs) is important for studies of the mechanism of many biological processes, such as RNA and DNA synthesis and DNA repair, as well as metabolic and therapeutic efficacy of nucleoside analogues. However, current methods are still unsatisfactory for determination of nucleotides in complex matrixes. Here we describe a novel method for the determination of RN and dRN pools in cells based on fast derivatization with (trimethylsilyl)diazomethane (TMSD) followed by quantification using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Derivatization was accomplished in 3 min, and each derivatized nucleotide not only had a sufficient retention on reversed-phase column by introduction of methyl groups but also exhibited a unique ion transition which consequently eliminated mutual interference in LC-MS/MS. Chromatographic separation was performed on a C₁₈ column with a simple acetonitrile-water gradient elution system, which avoided contamination and ion suppression caused by ion-pairing reagents. The developed method was fully validated and applied to the analysis of RNs and dRNs in cell samples. Moreover, results demonstrated that the applicability of this method could be extended to nucleoside analogues and their metabolites and could facilitate many applications in future studies.

Exploring the Antitumor Mechanism of High-Dose Cytarabine through the Metabolic Perturbations of Ribonucleotide and Deoxyribonucleotide in Human Promyelocytic Leukemia HL-60 Cells

Despite the apparent clinical benefits of high-dose cytarabine (Ara-C) over lower dose Ara-C in acute myeloid leukemia (AML) therapy, the mechanism behind high-dose Ara-C therapy remains uncertain. In this study, a LC-MS-based method was carried out to investigate the metabolic alteration of ribonucleotide and deoxyribonucleotide in human promyelocytic leukemia cells (HL-60) after treatment with Ara-C to reveal its antitumor mechanism. The metabolic results revealed that four nucleotides (ATP, ADP, CDP, and dCTP) could be used as potential biomarkers indicating the benefit of high-dose Ara-C over lower dose Ara-C treatment. Combining metabolic perturbation and cell cycle analysis, we conjectured that, apart from the acknowledged mechanism of Ara-C on tumor inhibition, high-dose Ara-C could present a specific action pathway. It was suggested that the pronounced rise in AMP/ATP ratio induced by high-dose Ara-C can trigger AMP-activated protein kinase (AMPK) and subsequently Forkhead Box, class O (FoxO), to promote cell cycle arrest. Moreover, the significant decrease in CDP pool induced by high-dose Ara-C might further accelerate the reduction of dCTP, which then aggravates DNA synthesis disturbance. As a result, all of these alterations led to heightened tumor inhibition. This study provides new insight in the investigation of potential mechanisms in the clinical benefits of high-dose Ara-C in therapy for AML.

Hydrophilic Interaction Liquid Chromatography/Mass Spectrometry: An Attractive and Prospective Method for the Quantitative Bioanalysis in Drug Metabolism

During the development, dosage optimization and safety evaluation of a drug, rapid and precise monitoring of administered drug and/or its metabolites in biological samples including blood, plasma, serum, tissues and saliva are vital. As drug biotransformation produces more hydrophilic metabolites for the enhancement of drug elimination, which is often a challenge for traditional reversed-phase liquid chromatography (RPLC) separation. Because hydrophilic interaction liquid chromatography (HILIC) is capable of retaining polar compounds and readily compatible with mass spectrometry (MS), HILIC has been used as a complementary separation technique to RPLC for analysis of polar metabolites, especially polar drugs and their metabolites. This review covers core aspects of HILIC-MS/MS method and overall profile of its application in analysis of drug and/or its metabolites. The emphasis of this paper has been placed on the applications of HILIC-MS/MS method in quantitative bioanalysis of drugs alone or along with their metabolites in drug metabolism studies in recent years. As a fundamental and critical step of bioanalytical method, conventional sample preparation techniques of biological matrices for the HILIC-MS/MS analysis of drugs and/or their metabolites are also briefly featured.

Aqueous extract of Sanguisorba officinalis blocks the Wnt/β-catenin signaling pathway in colorectal cancer cells

Sanguisorba officinalis (the Chinese name is DiYu, DY) exerts significant anti-proliferative activities against colorectal cancer (CRC) cells.

Simultaneous Determination of 11 Components in Yinzhihuang Preparations and Their Constituent Herbs by High-Performance Liquid Chromatography with Diode Array Detector

A simple and sensitive liquid chromatography method with diode array detector was established for simultaneous determination of 11 components (geniposidic acid, chlorogenic acid, caffeic acid, geniposide, luteoloside, isochlorogenic acid C, baicalin, luteolin, wogonoside, baicalein and wogonin) in various commercial Yinzhihuang preparations and their herbs by optimizing the extraction, separation and analytical conditions. Eleven components were identified on the basis of their retention times and mass spectra. Chromatographic separation was performed on a C18 analytical column with a gradient elution of acetonitrile and 0.1% formic acid water solution at a flow rate of 1.0 mL/min. The linearity, precision and accuracy of the data obtained were acceptable. The method was used to analyze four Yinzhihuang preparations (powder, capsule, oral liquid and injection) and related herbs (Radix Scutellariae, Flos Lonicerae, Herba Artemisiae Scopariae and Fructus gardeniae). Results suggested that the optimized method could be considered as a good approach to control the quality of Yinzhihuang preparations and their herbs.

Investigating the medicinal potential, material basis and mechanism of Polygoni Orientalis Fructus based on multi-technology integrated network pharmacology

BACKGROUND

Polygoni Orientalis Fructus (POF) refers to the dried ripe fruit of Polygonum orientale L. which has a long historical application in clinic for treatment of various conditions in China. However, its chemical constituents, pharmacological effects and their coupled correlation have not been intensively investigated.

PURPOSE

In present work, we aimed to elucidate the medicinal material basis, optimum indication and corresponding therapeutic mechanism of POF.

METHODS

The main phytochemical ingredients in POF were characterized by liquid chromatography-mass spectrometry (LC-MS) analysis. The optimum medicinal potential and corresponding molecular mechanism of POF were deduced based on integrated statistic pattern recognition and network pharmacology. The deduced pharmacologic efficacy and mechanism of POF were further validated through in vitro study in free-fatty acid (FFA)-induced LO2 cells.

RESULTS

Total 30 main phytochemical ingredients were identified in POF in which 18 ingredients were screened to yield 277 potential targets. Based on analyzing the quantitative data matrix of drug-disease targets by statistic pattern recognition, non-alcoholic fatty liver disease (NAFLD) was screened as the optimum indication of POF from 23 candidate diseases. Promising action targets (PPARG, IL6, TNF, IL1B, IKBKB, RELA, etc.) and signaling pathways (AMPK signaling pathway, NF-κB signaling pathway, etc.) were screened and refined to elucidate the therapeutic mechanism of POF against NAFLD based on network pharmacology. In vitro study demonstrated that POF effectively alleviated FFA-induced steatosis, oxidative stress, mitochondrial dysfunction and inflammation, and these beneficial effects were attributed to the activation of AMPK signaling pathway and suppression of NF-κB signaling pathway.

CONCLUSION

POF could be exploited as a promising phytotherapy in the treatment of NAFLD.

Simultaneous determination of baicalin, oroxylin A-7-O-glucuronide and wogonoside in rat plasma by UPLC-DAD and its application in pharmacokinetics of pure baicalin, Radix Scutellariae and Yinhuang granule

A novel UPLC-DAD method was developed and validated for the simultaneous determination of baicalin (baicalein-7-glucuronide, BG), oroxylin A-7-O-glucuronide (OAG) and wogonoside (WG) in rat plasma using rutin as the internal standard. Plasma samples were precipitated using acetonitrile containing 0.1% formic acid. Separation was performed on an Agilent Eclipse Plus C18 column (2.1 × 50 mm, 1.8 µm) using gradient acetonitrile and 0.2% formic acid water solution as mobile phase. The flow-rate was set at 0.4 mL/min and the eluate was detected at 275 nm. The method was linear over the ranges of 0.075-17.50, 0.050-12.60 and 0.056-14.10 µg/mL for BG, OAG and WG, respectively. The intra- and inter-day precisions were respectively <4.8% and 6.4%. All of the limits of detection of three analytes in rat plasma were 0.01 µg/mL, whereas the limits of quantification were, respectively, 0.035, 0.025 and, 0.025 µg/mL. This assay has been successfully applied to pharmacokinetics of BG, OAG and WG in rats after oral administration of Yinhuang granule (YHG) and comparative pharmacokinetics of BG in rats following oral administration of the pure BG, Radix Scutellariae (RS) or YHG. We speculate that some co-existing ingredients in RS or YHG may increase the absorption and elimination of BG in rat. This work may be helpful for the quality control of Yinhuang granule.

Bioconcentration and Metabolism of Emodin in Zebrafish Eleutheroembryos

Emodin is a major active anthraquinone of various herbal laxatives, which can exert many pharmacological effects. However, chronic use of anthranoid laxatives, even at low dosages, may cause melanosis coli (MC). It has been suggested that the accumulation of anthraquinones is a risk factor in the MC process. To investigate the accumulation of emodin, we conducted a bioconcentration study of emodin in zebrafish eleutheroembryos. Based on the economic cooperation and development (OECD) 305 test, zebrafish eleutheroembryos were exposed to emodin at a constant concentration for 48 h, before the test media were replaced by the blank medium for 24 h of depuration. To eliminate the effect of metabolism of emodin for assessment of the bioconcentration factor (BCF), we also conducted a modified test for which zebrafish eleutheroembryos were exposed to the non-renewed test media, whose emodin concentration decreased with time. At different exposure time points, zebrafish eleutheroembryos and exposure media were sampled for analysis of emodin concentration using HPLC-MS/MS. The results showed rapid accumulation of emodin in zebrafish eleutheroembryos to reach a steady-state concentration within 24 h. Meanwhile, emodin was actively metabolized by zebrafish eleutheroembryos to result in 29.5–40.7% of its elimination. In the groups with high or low concentrations of emodin, the standardized BCF (sBCF) values in the standard test were 24.0 and 20.0, while those in the modified test were 50.4 and 52.0. These results showed that emodin could accumulate in zebrafish eleutheroembryos when used for 48 h and beyond, suggesting that the accumulation of anthraquinones may be a risk factor in the MC process. Accordingly, emodin should be unsuitable for long-term use due to its accumulation.

MTBSTFA derivatization-LC-MS/MS approach for the quantitative analysis of endogenous nucleotides in human colorectal carcinoma cells

Endogenous ribonucleotides (RNs) and deoxyribonucleotides (dRNs) are important metabolites related to the pathogenesis of many diseases. In light of their physiological and pathological significances, a novel and sensitive pre-column derivatization method with N-(t-butyldimethylsilyl)-N-methyltrifluoroacetamide (MTBSTFA) was developed to determine RNs and dRNs in human cells using high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). A one-step extraction of cells with 85% methanol followed by a simple derivatization reaction within 5 min at room temperature contributed to shortened analysis time. The derivatives of 22 nucleoside mono-, di- and triphosphates were retained on the typical C18 column and eluted by ammonium acetate and acetonitrile in 9 min. Under these optimal conditions, good linearity was achieved in the tested calibration ranges. The lower limit of quantitation (LLOQ) was determined to be 0.1-0.4 μM for the tested RNs and 0.001-0.1 μM for dRNs. In addition, the precision (CV) was <15% and the RSD of stability was lower than 10.4%. Furthermore, this method was applied to quantify the endogenous nucleotides in human colorectal carcinoma cell lines HCT 116 exposed to 10-hydroxycamptothecin. In conclusion, our method has proven to be simple, rapid, sensitive, and reliable. It may be used for specific expanded studies on intracellular pharmacology in vitro.

Fecal microbiota transplantation for treatment of non-alcoholic fatty liver disease: Mechanism, clinical evidence, and prospect

The population of non-alcoholic fatty liver disease (NAFLD) patients along with relevant advanced liver disease is projected to continue growing, because currently no medications are approved for treatment. Fecal microbiota transplantation (FMT) is believed a novel and promising therapeutic approach based on the concept of the gut-liver axis in liver disease. There has been an increase in the number of pre-clinical and clinical studies evaluating FMT in NAFLD treatment, however, existing findings diverge on its effects. Herein, we briefly summarized the mechanism of FMT for NAFLD treatment, reviewed randomized controlled trials for evaluating its efficacy in NAFLD, and proposed the prospect of future trials on FMT.

Similarity and Specificity of Traditional Chinese Medicine Formulas for Management of Coronavirus Disease 2019 and Rheumatoid Arthritis

The pathogenesis similarity is leading to the introduction of drugs commonly used in rheumatoid arthritis (RA) into coronavirus disease (COVID-19) treatment. Traditional Chinese medicine (TCM) was widely used for the treatment of infectious diseases and rheumatic diseases. However, there is little knowledge of the relationship between COVID-19 and RA treatment employing TCM formulas. The present work was aimed to compare the similarity and specificity of TCM formulas for the management of COVID-19 and RA, as well as to deduce the potential mechanism of TCM for COVID-19 treatment. Two formulas including lianhuaqingwen (LHQW) and duhuojisheng (DHJS) were selected as the representatives of TCM for COVID-19 and RA treatment, respectively. An integrated network pharmacology was used to investigate their similarity and specificity. Although different herbs are present in the two formulas, they generated fairly similar ingredients, targets, interaction networks and enriched pathways, which were mainly involved in virus infection, inflammation, and immune dysregulation. Undoubtedly, they also exhibited their respective specificity. LHQW showed the cold property and lung channel tropism which dominated heat-clearing and lung-freeing, while DHJS showed the warm property and liver channel tropism. Herbal compatibility of LHQW was more in line with the rules of the TCM formula against coronavirus disease. Although both formulas suggested multifunctionality in virus infection and inflammation, LHQW was inclined to cope with virus infection, while DHJS was inclined to cope with inflammation. Therefore, LHQW was reliable for providing the desired efficacy in COVID-19 management because of its cold property, lung channel tropism, and multifunctionality for coping with virus infection and inflammation.

Profiling of ribonucleotides and deoxyribonucleotides pools in response to DNA damage and repair induced by methyl methanesulfonate in cancer and normal cells

The absolute and relative pool sizes of deoxyribonucleotides (dRNs) are essential in DNA replication fidelity, DNA damage and repair. We found in this study that although DNA damage induced by methyl methanesulfonate (MMS) seemed similar in cancer (HepG2) and normal (LO2) cells, more extensive alterations in ribonucleotides (RNs) and dRNs pools occurred in HepG2 cells indicating that HepG2 cells were more vigilant to DNA damage. After 10 h repair, RNs pools were still severely perturbed in LO2 cells. Compared to LO2 cells, deoxyribonucleotide triphosphates (dNTPs) pools in HepG2 cells elevated by more folds which could facilitate more efficient DNA repair and improve survival probability following DNA damage, although this should definitely lead to higher mutation rates. DNA repair was more efficient in HepG2 cells at S phase and it partly came to an end while DNA repair was still uncompleted in LO2 cells outside S phase. In conclusion, our results demonstrated that HepG2 and LO2 cells presented many differences in nucleotide metabolism, cell cycle checkpoints and DNA repair pathways in response to DNA damage, which could be potential targets for cancer treatment.

Screening for Potential Bioactive Components in Ginkgo biloba Extract by the Rat Renal Tubular Epithelial Cell Extraction and LC-MS/MS

Rat renal tubular epithelial cell (RTEC) cultured with high glucose has been used to observe the protective effect of Ginkgo biloba extract (GBE) against diabetic nephropathy (DN). The compounds in GBE binding with cell membrane or entering into cell are still unknown, which may be potential bioactive components. In this paper, a powerful method for screening and analyzing the potential bioactive components from GBE was developed using cell extraction coupled with high performance liquid chromatography tandem mass spectrometry (LC-MS/MS). 8 prototype compounds and 5 metabolites were obtained, among which 6 prototype compounds and 1 metabolite were identified or tentatively characterized as rutin, bilobalide, ginkgolide B, ginkgolide C, genkwanin, apigenin and diosmetin by comparing their retention times and MS spectra with those of authentic standards or literature data. The 6 prototype compounds were further quantitatively analyzed using electrospray ionization in negative mode multiple reaction monitoring (MRM). The results showed that high glucose changed the Tmax, MRT(0-t), Cmax and AUC(0-t) of all observed compounds and decreased the t1/2 of genkwanin and apigenin, significantly. The overall findings indicate that 8 prototype compounds may be the potential bioactive components of GBE with preventive effect against DN and the method of RTEC extraction coupled with LC-MS/MS technology screening method we developed is a feasible, rapid, and useful tool for screening and analyzing potential bioactive components.