Metabolomics-based comparative analysis of the effects of host and environment on Viscum coloratum metabolites and antioxidative activities

Viscum coloratum (Kom.) Nakai is a well-known medicinal hemiparasite widely distributed in Asia. The synthesis and accumulation of its metabolites are affected by both environmental factors and the host plants, while the latter of which is usually overlooked. The purpose of this study was to comprehensively evaluate the effects of host and habitat on the metabolites in V. coloratum through multiple chemical and biological approaches. The metabolite profile of V. coloratum harvested from three different host plants in two habitats were determined by multiple chemical methods including high-performance liquid chromatography-ultraviolet (HPLC-UV), gas chromatography-flame ionization detector (GC-FID) and ultra-performance liquid chromatography quadrupole time of flight mass spectrometry (UPLC-QTOF/MS). The differences in antioxidant efficacy of V. coloratum were determined based on multiple in vitro models. The multivariate statistical analysis and data fusion strategy were applied to analyze the differences in metabolite profile and antioxidant activity of V. coloratum. Results indicated that the metabolite profile obtained by various chemical approaches was simultaneously affected by host and environment factors, and the environment plays a key role. Meanwhile, three main differential metabolites between two environment groups were identified. The results of antioxidant assay indicated that the environment has greater effects on the biological activity of V. coloratum than the host. Therefore, we conclude that the integration of various chemical and biological approaches combined with multivariate statistical and data fusion analysis, which can determine the influences of host plant and habitat on the metabolites, is a powerful strategy to control the quality of semi-parasitic herbal medicine.     

基于血浆代谢组学的蒙药三臣小儿退热贴膏解热作用机制研究

目的基于血浆代谢组学探究蒙药三臣小儿退热贴膏的解热作用及其机制。方法 SD大鼠随机分为对照组、模型组、阿司匹林(100mg/kg)组以及三臣小儿退热贴膏高、中、低剂量(16、8、4mg/kg)组和空白基质贴膏组,模型组和各给药组采用干酵母法建立发热模型,造模后第4、7小时各给药组给予相应药物进行干预,造模后每小时测量1次大鼠体温。采集造模后10 h大鼠血浆,采用超高效液相色谱-四极杆-静电场轨道阱高分辨质谱(UPLC-QE-MS)法并结合多元统计分析,检测各组大鼠血浆代谢相关生物标志物的变化。结果造模4h后模型组大鼠体温显著升高(P0.01),造模后5h三臣小儿退热贴膏组大鼠体温显著降低(P0.01),呈剂量相关性。基于代谢组学发现模型组大鼠血浆中7种潜在的生物标志物发生明显变化,分别为酮亮氨酸、鞘磷脂[d17∶1/24∶1(15Z)]、鞘磷脂[d18∶1/24∶1(15Z)]、鞘磷脂[d18∶1/18∶1(9Z)]、磷脂酰胆碱(16∶0/14∶0)、磷脂酰胆碱(18∶0/15∶0)、磷脂酰胆碱(16∶0/16∶0);三臣小儿退热贴膏组大鼠血浆中上述7种生物标志物含量均显著回调,且牛磺酸和异柠檬酸含量升高。代谢通路分析显示,三臣小儿退热贴膏能够影响牛磺酸和亚牛磺酸代谢、乙醛酸和二元酸代谢、柠檬酸循环、氨基酸代谢、初级胆汁酸生物合成、α-亚麻酸代谢、烟酸和烟酰胺代谢、鞘脂代谢等多种代谢通路。结论三臣小儿退热贴膏对干酵母致发热大鼠模型具有较好的解热作用,其药效与阿司匹林相当,其解热机制与酶抑制、脂肪代谢、氨基酸及能量代谢等多通路协同作用有关。     

葛根芩连汤干预2型糖尿病前期大鼠的代谢机制研究

目的探讨葛根芩连汤对高脂诱导的2型糖尿病大鼠预防作用的代谢机制。方法将SD大鼠随机分为正常组(8只)和高脂造模组(40只),分别使用基础饲料和高脂饲料喂养12周。高脂造模组大鼠产生胰岛素抵抗(IR)后,将高脂造模组大鼠再随机分为模型组及葛根芩连汤低、中、高剂量组(1.65、4.96、14.86 g·kg-1),每组8只。模型组及不同剂量给药组继续给予高脂饲料喂养,给药组给予不同剂量的葛根芩连汤进行干预,灌胃给药,给药体积为10 mL·kg-1,每天1次,连续16周。检测大鼠空腹血糖值及空腹胰岛素含量,计算IR指数;使用超高效液相色谱-四级杆飞行时间串联质谱(UHPLC/Q-TOF-MS)结合多元分析方法,分析大鼠血清中的内源性代谢物及其变化差异,寻找葛根芩连汤干预IR大鼠及预防2型糖尿病的潜在生物标记物。结果高脂饲料喂养12周后,与正常组比较,造模组大鼠的IR指数明显升高(P<0.05),血糖无明显变化(P>0.05)。给药16周后,与正常组比较,模型组大鼠的IR指数及血糖值均显著升高(P<0.05,P<0.01);与模型组比较,葛根芩连汤低、中剂量组大鼠的IR指数显著降低(P<0.01),葛根芩连汤高剂量组的IR指数无明显变化(P>0.05);葛根芩连汤低剂量组的空腹血糖值明显降低(P<0.05),而葛根芩连汤中、高剂量组的空腹血糖值无明显变化(P>0.05)。大鼠血清代谢组分析鉴定共得到4种潜在代谢标志物,分别是Hippuric acid(马尿酸)、12-Ketodeoxycholic acid(12-去氧胆酸)、3-Oxo-4,6-choladienoic acid和LysoPC[20∶4(5Z,8Z,11Z,14Z)](溶血磷脂酰胆碱,LPC)。结论葛根芩连汤可以降低IR大鼠的胰岛素抵抗指数,同时可预防血糖升高,其机制可能与调节胆汁酸代谢、磷脂代谢以及肠道菌群代谢有关。     

基于NMR代谢组学技术的款冬花生品与蜜炙品化学成分比较

目的探究款冬花蜜炙的科学内涵。方法基于NMR代谢组学技术对款冬花生品和蜜炙品进行分析,采用主成分分析(PCA)、正交偏最小二乘法辨别分析(OPLS-DA)以及单变量分析对款冬花蜜炙前后化学成分进行比较。结果款冬花的代谢指纹图谱共指认出40种代谢物,多元统计结果显示款冬花蜜炙品和生品之间存在显著差异,蜜炙后初级代谢产物1-O-乙基-β-D-葡萄糖苷、β-葡萄糖、蔗糖、α-葡萄糖的量明显升高,缬氨酸、天冬氨酸、苏氨酸的量降低;次级代谢产物款冬酮、芦丁的量升高,绿原酸、咖啡酸等有机酸的量有所降低。结论从整体化学组成上比较了款冬花生品与蜜炙品的差异,为其蜜炙的科学内涵研究奠定了基础。     

Catastrophic ATP loss underlies a metabolic combination therapy tailored for MYCN-amplified neuroblastoma

MYCN-amplified neuroblastoma is a lethal subset of pediatric cancer. MYCN drives numerous effects in the cell, including metabolic changes that are critical for oncogenesis. The understanding that both compensatory pathways and intrinsic redundancy in cell systems exists implies that the use of combination therapies for effective and durable responses is necessary. Additionally, the most effective targeted therapies exploit an “Achilles’ heel” and are tailored to the genetics of the cancer under study. We performed an unbiased screen on select metabolic targeted therapy combinations and correlated sensitivity with over 20 subsets of cancer. We found that MYCN-amplified neuroblastoma is hypersensitive to the combination of an inhibitor of the lactate transporter MCT1, AZD3965, and complex I of the mitochondrion, phenformin. Our data demonstrate that MCT4 is highly correlated with resistance to the combination in the screen and lowly expressed in MYCN-amplified neuroblastoma. Low MCT4 combines with high expression of the MCT2 and MCT1 chaperone CD147 in MYCN-amplified neuroblastoma, altogether conferring sensitivity to the AZD3965 and phenformin combination. The result is simultaneous disruption of glycolysis and oxidative phosphorylation, resulting in dramatic disruption of adenosine triphosphate (ATP) production, endoplasmic reticulum stress, and cell death. In mouse models of MYCN-amplified neuroblastoma, the combination was tolerable at concentrations where it shrank tumors and did not increase white-blood-cell toxicity compared to single drugs. Therefore, we demonstrate that a metabolic combination screen can identify vulnerabilities in subsets of cancer and put forth a metabolic combination therapy tailored for MYCN-amplified neuroblastoma that demonstrates efficacy and tolerability in vivo.

Despite their relative rarity compared to blood cancers, solid-tumor pediatric cancers are now the leading cause of pediatric cancer-related deaths. Among the most deadly is high-risk neuroblastoma (NB): amplification of MYCN confers high risk and is the clear driver of NB in these cancers (1). As such, MYCN remains the most important drug target in NB and one of the most important in pediatric cancer. Unfortunately, direct chemical targeting of MYCN has not yet been successful, and despite advancements in anti-GD2 immunotherapy (2), alternate ways of targeting MYCN-amplified NB may be needed to successfully treat this cancer.One approach is to find tumor-specific vulnerabilities, which are exploitable pharmacologically. Many efforts, including ours (3), have exhaustively looked for kinase inhibitors with particular efficacy in MYCN-amplified NBs. However, the emerging picture is a lack of kinase inhibitor efficacy in MYCN-amplified NB. Other vulnerabilities may be classified under the broad category of drugs targeting epigenetic modifiers. For example, using a CRISPR/Cas9 screen, Stegmaier and colleagues demonstrated that MYCN-amplified NB may be susceptible to targeting the H3K27me methylase EZH2 (4); in a different study, they demonstrated the susceptibility of MYCN-amplified NB to the combination of BRD4 inhibitors with CDK7 inhibitors (5). In addition, Thiele and colleagues (6) demonstrated high-risk NBs were susceptible to inhibition of the lysine methyltransferase SETD8. As promising as these data are, it remains unknown whether tolerability and/or clinical activity in MYCN-amplified NB will occur and SETD8, BRD4, and CDK7 inhibitors so far are not in the pediatric clinic. Cell death inducers constitute a third category. To this point, we recently uncovered a susceptibility of MYCN-amplified NB to the BCL-2 inhibitor venetoclax (3), confirmed by others (7). There, MYCN-driven NOXA expression sensitizes cells to venetoclax (3). Venetoclax is now in early phase trials in pediatric patients including those with NB ({"type":"clinical-trial","attrs":{"text":"NCT03236857","term_id":"NCT03236857"}}NCT03236857). It remains to be seen whether or not it will elicit responses in NB patients as a single agent.A fourth distinct category of therapeutic strategies to indirectly target oncogenes is through metabolism targeting, involving the growing coterie of drugs targeting the pathways fulfilling the high-energy demands of cancer cells. A major energy currency in cells is adenosine triphosphate (ATP). The Warburg effect describes the propensity of cancer cells (and highly proliferating normal cells) to produce ATP in the presence of oxygen with the less efficient, extramitochondrial glycolysis, as opposed to the more efficient mitochondria-based oxidative phosphorylation occurring in most noncancerous cells (8). The mechanistic explanation of the Warburg effect and how it might benefit cancer cells has been revised dramatically over the years. It was originally proposed that mitochondria from cancer cells were defective and lacked oxidative phosphorylation capabilities (9); on the contrary, emerging data show that many cancers rely on oxidative phosphorylation to facilitate the generation of ATP (8, 10). Interestingly, while amplified MYCN directly regulates the expression of many of the key glycolytic enzymes and as such contributes to the Warburg effect (11, 12), a study utilizing a Seahorse respirator demonstrated that a MYCN-amplified NB cell line favored oxidative phosphorylation over glycolysis for the metabolic needs, while the reverse was true for a MYCN wild-type NB cell line (13). In an independent study, MYCN was associated with higher glycolytic flux and oxidative phosphorylation and conferred sensitivity to fatty acid oxidation disruption (12). Overall, since c-MYC, which shares ∼40% binding homology to DNA-binding sites throughout the genome with MYCN, has been extensively characterized as a metabolic master regulator (14, 15), it is likely there are other MYCN-driven metabolic processes that may represent significant drug targets.Monocarboxylate transporters (MCTs) consist of four members (MCT1–4) in mammalian cells. Among their most critical substrates are lactate and pyruvate; MCT1 and MCT4 are responsible for lactate export across the plasma membrane to the extracellular space (16). AZD3965 (17) (AstraZeneca) is the first in-class–specific MCT1/2 dual inhibitor and is currently in early phase trials for diverse cancers; however, other inhibitors from different companies have recently been developed as well (18). Of note, AZD3965 has demonstrated good tolerability in diverse patients (clinical trial number {"type":"clinical-trial","attrs":{"text":"NCT01791595","term_id":"NCT01791595"}}NCT01791595). Although rare (65 cases/100,000 person-years), lactic acidosis led to the market retrieval of phenformin in America (19), yet phenformin remains in use as a type II antidiabetic drug in Europe, functioning centrally as a mitochondrial complex I electron transport chain (ETC) inhibitor. Phenformin reduces both glycolytic intermediates and pyruvate, increases shunting of glucose-derived carbon (increasing total lactate production), and markedly reduces tricarboxylic acid cycle intermediates (20). Indeed, there has been a recent resurgence in interest in the use of phenformin to treat cancer. For example, in BRAF mutant melanoma, phenformin sensitized cells to BRAF inhibitor through cooperative suppression of the metabolic sensor pathway mTORC1 (21). These preclinical data have led to a clinical trial of phenformin in combination with BRAF inhibitor in BRAF mutant melanoma ({"type":"clinical-trial","attrs":{"text":"NCT03026517","term_id":"NCT03026517"}}NCT03026517). Overall, while targeting individual metabolic pathways has demonstrated some preclinical success in different cancer models, it is limited with significant redundancy in pathways to generate ATP and regenerate NAD+ (22). We therefore assessed potential combination therapies involving metabolic targeting drugs to identify a strategy for MYCN-amplified NB.     

Novel serum metabolomics‐based approach by gas chromatography/triple quadrupole mass spectrometry for detection of human skin cancers: Candidate biomarkers

Skin cancer incidence rates are continuing to rise; however, if detected at an early stage, they can be cured with minimally invasive treatment. Therefore, the identification of novel and robust biomarkers for the early detection of skin cancer is required to improve the quality of life of the patient after treatment. In the present study, we aimed to identify novel biomarkers of skin cancers. We carried out serum metabolomics using gas chromatography/triple quadrupole mass spectrometry for two types of skin cancer: squamous cell carcinoma and melanoma. The changes in the expression of metabolites compared with healthy volunteers were analyzed by principal component analysis. Among all 118 metabolites, 27 in patients with squamous cell carcinoma and 33 in patients with melanoma showed significant changes in comparison with healthy volunteers. Principal component analysis showed that both skin cancer groups could be distinguished from the healthy volunteers group. We further investigated the specific metabolites most useful for these distinctions. In the squamous cell carcinoma group, these metabolites were glycerol, 4‐hydroxybenzoic acid, sebacic acid, fucose and suberic acid. In the melanoma group, these metabolites were glutamic acid, sebacic acid, suberic acid, 4‐hydroxybenzoic acid and phenylalanine. The present study identified several metabolites that were distinct for certain skin cancer types, which could potentially be used as diagnostic biomarkers leading to novel clinical management strategies.     

Understanding the metabolome – challenges for metabolomics

Metabolomics is a comprehensive method for metabolite assessment, measuring the overall metabolic signature of biological samples. This approach opens up many possibilities in areas such as new biomarker discovery and hypothesis generation. The application of metabolomics is growing rapidly but many challenges must first be addressed before it can reach its true potential. Metabolomics organisations are currently working towards guidelines for commonality in metabolomics experiments as development of optimal methodologies and study designs are needed. Blood and urine appear to be the most useful biofluids for nutrition research, but an array of biofluids, cells and tissues can be used. The key steps required for the successful understanding of metabolomics data are compound identification and biological interpretation. Many databases of compounds are available but are still under construction with much information remaining to be populated. An understanding of the effects of normal physiological variation on metabolic profiles is essential for accurate interpretation of profile changes, particularly in human studies, because of diversity in lifestyle and environmental factors. The effects of factors such as ethnicity, gender, age, body composition, health, dietary intake, physical activity, gut microflora and stress need to be further explored in order to advance the understanding of the human metabolome and therefore improve data interpretation.