Impact of intratumoral heterogeneity of breast cancer tissue on quantitative metabolomics using high‐resolution magic angle spinning 1H NMR spectroscopy

High‐resolution magic angle spinning (HR MAS) nuclear magnetic resonance (NMR) spectroscopy is increasingly being used to study metabolite levels in human breast cancer tissue, assessing, for instance, correlations with prognostic factors, survival outcome or therapeutic response. However, the impact of intratumoral heterogeneity on metabolite levels in breast tumor tissue has not been studied comprehensively. More specifically, when biopsy material is analyzed, it remains questionable whether one biopsy is representative of the entire tumor. Therefore, multi‐core sampling (n = 6) of tumor tissue from three patients with breast cancer, followed by lipid (0.9‐ and 1.3‐ppm signals) and metabolite quantification using HR MAS ¹H NMR, was performed, resulting in the quantification of 32 metabolites. The mean relative standard deviation across all metabolites for the six tumor cores sampled from each of the three tumors ranged from 0.48 to 0.74. This was considerably higher when compared with a morphologically more homogeneous tissue type, here represented by murine liver (0.16–0.20). Despite the seemingly high variability observed within the tumor tissue, a random forest classifier trained on the original sample set (training set) was, with one exception, able to correctly predict the tumor identity of an independent series of cores (test set) that were additionally sampled from the same three tumors and analyzed blindly. Moreover, significant differences between the tumors were identified using one‐way analysis of variance (ANOVA), indicating that the intertumoral differences for many metabolites were larger than the intratumoral differences for these three tumors. That intertumoral differences, on average, were larger than intratumoral differences was further supported by the analysis of duplicate tissue cores from 15 additional breast tumors. In summary, despite the observed intratumoral variability, the results of the present study suggest that the analysis of one, or a few, replicates per tumor may be acceptable, and supports the feasibility of performing reliable analyses of patient tissue.     

甜菜碱对金黄色葡萄球菌生物膜形成抑制与分散的作用

目的研究金黄色葡萄球菌生物膜形成及甜菜碱对其抑制与分散的作用。方法采用结晶紫染色法分别测定终浓度为1.0 g/L的甜菜碱对20株金黄色葡萄球菌生物膜形成的抑制能力和甜菜碱对金黄色葡萄球菌生物膜的分散能力。结果 20株金黄色葡萄球菌均能形成生物膜,其中甲氧西林敏感的金黄色葡萄球菌(MSSA)培养24 h时形成生物膜吸光度值(A_(590 nm))达峰值,为1.99±0.53;耐甲氧西林金黄色葡萄球菌(MRSA)培养48 h时形成生物膜A_(590 nm)达峰值,为1.13±0.47。加入甜菜碱共培养后,MSSA培养24 h后生物膜A_(590 nm)为1.74±0.61,MRSA培养48 h后生物膜A_(590 nm)为0.40±0.12,与对照组相比差异均有统计学意义(t值分别为2.43和5.84,P均0.05)。当生物膜形成后加入甜菜碱,与对照组相比,MSSA和MRSA的生物膜A_(590 nm)差异无统计学意义(P0.05)。结论 1.0 g/L甜菜碱对金黄色葡萄球菌生物膜的形成具有良好的抑制作用,但不能分散已经形成的生物膜。     

Role of betaine in liver injury induced by the exposure to ionizing radiation

Oxidative stress, apoptosis, and fibrosis may play a major role in the development of radiation‐induced liver damage. Betaine, a native compound widely present in beetroot, was reported to possess hepato‐protective properties. The objective of this study was to investigate the influence of betaine on radiation‐induced liver damage. Animals were exposed to 9 Gy applied in 3 doses of 3 Gy/wk. Betaine (400 mg/kg/d), was orally supplemented to rats after the first radiation dose, and daily during the irradiation period. Animals were sacrificed 1 day after the last dose of radiation. The results showed that irradiation has induced oxidative stress in the liver denoted by a significant elevation in malondialdehyde, protein carbonyl, and 8‐hydroxy‐2‐deoxyguanosine with a significant reduction in catalase activity and glutathione (GSH) content. The activity of the detoxification enzyme cytochrome P450 (CYP450) increased while GSH transferase (GSH‐T) decreased. The activity of the apoptotic marker caspase‐3 increased concomitant with increased hyaluronic acid, hydroxyproline, laminin (LN), and collagen IV. These alterations were associated with a significant increase of gamma‐glutamyl transferase, alkaline phosphatase and alanine and aspartate aminotransferase markers of liver dysfunction. Betaine treatment has significantly attenuated oxidative stress, decreased the activity of CYP450, enhanced GSH‐T, reduced the activity of caspase‐3, and the level of fibrotic markers concomitant with a significant improvement of liver function. In conclusion, betaine through its antioxidant activity and by enhancing liver detoxification and reducing apoptosis may alleviate the progression of liver fibrosis and exert a beneficial impact on radiation‐induced liver damage.     

甜菜碱对大鼠肝纤维化的保护作用研究

目的观察甜菜碱对复合致病因素诱导肝纤维化大鼠的保护作用。方法复合致病因素法诱导制备肝纤维化大鼠模型,观察灌服甜菜碱对肝纤维化大鼠血清丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)、内毒素(ET)、同型半胱氨酸(Hcy)、透明质酸(HA)、层粘连蛋白(LN)、IV胶原蛋白(IV-C)、Ⅲ型前胶原蛋白(PC-Ⅲ)及肝组织肿瘤坏死因子α(TNF-α)、一氧化氮(NO)、过氧亚硝酸盐阴离子(ONOO-)、丙二醛(MDA)的变化,并采用HE和VG染色分别观察肝损伤和肝纤维化情况。结果大鼠肝纤维化模型复制成功。给与三个剂量的甜菜碱后,肝组织病理损伤改善。反映大鼠肝功能(ALT、AST)及肝纤维化指标(HA、LN、IV-C)的水平不同程度降低。血清内毒素、肝组织NO、MDA水平亦明显降低。同时Hcy及ONOO-在中、高剂量组明显降低,而TNF-α的降低在高剂量组中也具有明显的统计学差异。结论甜菜碱可抑制复合因素诱导的大鼠肝纤维化,其作用可能是通过降低大鼠体内高同型半胱氨酸、调节炎性细胞因子和氧化应激实现的。     

地骨皮活性成分对高糖致肾小球系膜细胞增殖及细胞外基质的影响

目的?观察地骨皮中有效成分对高糖刺激的肾小球系膜细胞的增殖以及细胞外基质分泌的影响,研究其对糖尿病肾病的保护机制。方法?体外培养肾小球系膜细胞,分为高糖模型组（葡萄糖浓度为30?mmol/L）,空白对照组（葡萄糖浓度为5.5?mmol/L）,甜菜碱、山奈酚5个浓度剂量组（0.01、0.1、1、10、100?μmol/L）,用MTT法观察系膜细胞增殖情况,ELISA法观察细胞外基质分泌情况。结果?与高糖模型组比较,不同剂量甜菜碱组和山奈酚组,对高糖致肾小球系膜细胞增殖有不同程度的抑制。甜菜碱、山奈酚均能抑制细胞外基质的分泌,与高糖模型组比较有显著性差异（P<0.05~0.01）。结论?地骨皮中有效成分甜菜碱和山奈酚均具有抑制高糖刺激下系膜细胞增殖以及细胞外基质分泌的作用,推测地骨皮中有效成分具有治疗糖尿病肾病的作用。      

甜菜碱促进小鼠脾淋巴细胞增殖作用的钙通道机制研究

目的:研究甜菜碱促进小鼠脾淋巴细胞的增殖作用与钙通道的关系.方法:采用清洁级BALB/c小鼠分离小鼠脾淋巴细胞后体外培养的方式获得小鼠脾淋巴细胞,分为阴性对照组、Con A组、甜菜碱0.04,0.4,4,20 mmol·L~(-1)组.分别采用MTT法观察甜菜碱对小鼠脾淋巴细胞增殖的作用,流式细胞术测定甜菜碱对小鼠脾淋巴细胞周期的变化,激光共聚焦扫描显微镜观察甜菜碱对小鼠脾淋巴细胞内钙浓度的变化及加入不同钙通道阻滞剂后细胞内钙浓度的变化.结果:4,20 mmol·L~(-1)甜菜碱体外作用于小鼠脾淋巴细胞12 h促进小鼠脾淋巴细胞增殖,0.04,0.4,4,20 mmol·L~(-1)甜菜碱分别体外作用于小鼠脾淋巴细胞24,48 h均促进小鼠脾淋巴细胞增殖,以4 mmol·L~(-1)甜菜碱作用24 h效果最好;4 mmol·L~(-1)甜菜碱作用小鼠脾淋巴细胞4,6,18,24 h能促使小鼠脾淋巴细胞由G_0/G_1期进入S期,并以18 h效果最为明显;4 mmol·L~(-1)甜菜碱作用于淋巴细胞6,12,18 h,脾淋巴细胞内Ca~(2+)浓度明显升高(P＜0.01),以6 h效果最明显;钙通道阻滞剂硝苯地平、地尔硫卓、咪贝地尔、金雀异黄素对甜菜碱升高小鼠脾淋巴细胞内钙离子浓度没有影响,而维拉帕米、新霉素、肝素、普鲁卡因能阻断甜菜碱升高小鼠脾淋巴细胞内钙离子浓度.结论:甜菜碱通过升高小鼠脾淋巴细胞内钙离子浓度而促进小鼠脾淋巴细胞由G_0/G_1期进入S期,促小鼠脾淋巴细胞增殖的作用.细胞内钙离子浓度升高主要通过2个途径:影响G蛋白介导的L-型电压门控钙通道的α_1亚单位而引起外钙内流;影响胞内钙库的IP_3R钙通道和RyR钙通道而引起内钙释放.     

甜菜碱对大鼠酒精性肝病的治疗作用

目的：观察甜菜碱对大鼠酒精性肝病模型的治疗作用并探讨其作用机制。方法：通过建立大鼠酒精性肝病模型,分别以甜菜碱不同剂量（200～800mg／kg）干预4周,然后测定大鼠血浆总同型半胱氨酸（tHcy）浓度、ALT、AST及肝组织中丙二醛（MDA）和谷胱甘肽（GSH）含量,同时观察肝脏的病理组织学变化。结果：经甜菜碱干预的大鼠血清中tHcy、ALT、AST水平和肝组织中MDA的含量明显低于模型组（P〈0．05或0．01）,同时肝组织中的GSH含量明显高于模型组（P〈0．05或O．01）。肝组织形态学评估表明,甜菜碱显著减少了肝脂质沉积和炎症细胞的浸润。结论：甜菜碱对大鼠酒精性肝病模型有较好的治疗作用,其作用机制可能与其纠正甲硫氨酸循环的异常和转硫基作用的异常有关。     

液相色谱-串联质谱联用法测定心脑欣片中甜菜碱含量

目的：建立测定心脑欣片中甜菜碱含量的方法。方法采用液相色谱-串联质谱联用（LC - MS / MS）法测定甜菜碱的含量,以电喷雾离子源（ESI）正离子模式将样品离子化,多反应监测（MRM）模式下对甜菜碱（ m / z 118.20→57.92和118.20→59.00）进行测定。色谱柱为 Venusil HILIC 柱（100 mm×2.1 mm,3μm）,流动相为乙腈-水（80：20）,流速为0.3 mL / min。结果甜菜碱进样质量浓度在4.44-177.6 ng / mL 范围内与峰面积积分值线性关系良好（ r =0.9999）,平均回收率为99.45%,RSD 为1.43%（ n =6）。结论该方法简便、可靠、准确,可作为测定心脑欣片中甜菜碱含量的方法。     

Radioactive choline metabolism in guinea pig gallbladder

Acetylcholine may be released from gallbladder intrinsic nerves in response to cholecystokinin stimulation. This study characterized metabolites of [¹⁴C]choline produced in the gallbladder and released during incubation, with or without cholecystokinin-octapeptide. Radiolabeled [¹⁴C]choline was applied to the mucosal or muscle surface of intact guinea pig gallbladders in an organ bath. After radiolabeling, gallbladders were incubated with or without the contractile agonist cholecystokinin-octapeptide. Metabolites of [¹⁴C]choline were identified in gallbladder tissue and incubation buffers using HPLC and thin-layer chromatography. The major metabolites of [¹⁴C]choline were betaine and phosphocholine. [¹⁴C]Phosphocholine was incorporated slowly into [¹⁴C]phosphatidylcholine. [¹⁴C]Choline was released into buffers during incubation. [¹⁴C]Acetylcholine constituted less than 1% of radiolabel in the gallbladder. There was no identifiable [¹⁴C]acetylcholine released in buffers. Cholecystokinin-octapeptide did not affect choline metabolism. These studies showed that choline in the gallbladder is metabolized along pathways similar to those in the liver. Gallbladders released mostly choline, rather than acetylcholine, even during hormonally induced contraction.This project was supported by the Research and Development Office of the Department of Veterans Affairs.