Metabolic difference between patient-derived xenograft model of pancreatic ductal adenocarcinoma and corresponding primary tumor.

BACKGROUND: Patients-derived xenograft (PDX) model have been widely used for tumor biological and pathological studies. However, the metabolic similarity of PDX tumor to the primary cancer (PC) is still unknown. METHODS: In present study, we established PDX model by engrafting primary tumor of pancreatic ductal adenocarcinoma (PDAC), and then compared the tumor metabolomics of PC, the first generation of PDX tumor (PDXG1), and the third generation of PDX tumor (PDXG3) by using 1H NMR spectroscopy. Then, we assessed the differences in response to chemotherapy between PDXG1 and PDXG3 and corresponding metabolomic differences in drug-resistant tumor tissues. To evaluate the metabolomic similarity of PDX to PC, we also compared the metabolomic difference of cell-derived xenograft (CDX) vs. PC and PDX vs. PC. RESULTS: After engraftment, PDXG1 tumor had a low level of lactate, pyruvate, citrate and multiple amino acids (AAs) compared with PC. Metabolite sets enrichment and metabolic pathway analyses implied that glycolysis metabolisms were suppressed in PDXG1 tumor, and tricarboxylic acid cycle (TCA)-associated anaplerosis pathways, such as amino acids metabolisms, were enhanced. Then, after multiple passages of PDX, the altered glycolysis and TCA-associated anaplerosis pathways were partially recovered. Although no significant difference was observed in the response of PDXG1 and PDXG3 to chemotherapy, the difference in glycolysis and amino acids metabolism between PDXG1 and PDXG3 could still be maintained. In addition, the metabolomic difference between PC and CDX models were much larger than that of PDX model and PC, indicating that PDX model still retain more metabolic characteristics of primary tumor which is more suitable for tumor-associated metabolism research. CONCLUSIONS: Compared with primary tumor, PDX models have obvious difference in metabolomic level. These findings can help us design in vivo tumor metabolomics research legitimately and analyze the underlying mechanism of tumor metabolic biology thoughtfully.

Metabolic responses to the occurrence and chemotherapy of pancreatic cancer: biomarker identification and prognosis prediction.

As the most malignant tumor, the prognosis of pancreatic cancer is not ideal even in the small number of patients who can undergo radical surgery. As a highly heterogeneous tumor, chemotherapy resistance is a major factor leading to decreased efficacy and postoperative recurrence of pancreatic cancer. In this study, nuclear magnetic resonance (NMR)-based metabolomics was applied to identify serum metabolic characteristics of pancreatic ductal adenocarcinoma (PDAC) and screen the potential biomarkers for its diagnosis. Metabolic changes of patients with different CA19-9 levels during postoperative chemotherapy were also monitored and compared to identify the differential metabolites that may affect the efficacy of chemotherapy. Finally, 19 potential serum biomarkers were screened to serve the diagnosis of PDAC, and significant metabolic differences between the two CA19-9 stratifications of PDAC were involved in energy metabolism, lipid metabolism, amino acid metabolism, and citric acid metabolism. Enrichment analysis of metabolic pathways revealed six shared pathways by PDAC and chemotherapy such as alanine, aspartate and glutamate metabolism, arginine biosynthesis, glutamine and glutamate metabolism, citrate cycle, pyruvate metabolism, and glycogolysis/gluconeogeneis. The similarity between the metabolic characteristics of PDAC and the metabolic responses to chemotherapy provided a reference for clinical prediction of benefits of postoperative chemotherapy in PDAC patients.

Metabolomic analysis reveals the biological characteristics of giant congenital melanocytic nevi.

Giant congenital melanocytic nevi (GCMN) is a congenital cutaneous developmental deformity tumor that usually occurs at birth or in the first few weeks after birth, but its pathogenesis is still unclear. In this study, nuclear magnetic resonance-based metabolomics strategy was employed to evaluate the metabolic variations in serum and urine of the GCMN patients in order to understand its underlying biochemical mechanism and provide a potential intervention idea. Twenty-nine metabolites were observed to change significantly in serum and urine metabolomes, which are mainly involved in a variety of metabolic pathways including glyoxylate and dicarboxylate metabolism, TCA cycle and metabolisms of amino acids. The substantial cores of all the disturbed metabolic pathways are related to amino acid metabolism and carbohydrate metabolism and regulate the physiological state of the GCMN patients. Our results provide the physiological basis and physiological responses of GCMN and will be helpful for better understanding the molecular mechanisms of GCMN in future research.

Discover boy specific-biomarkers and reveal gender-related metabolic differences in central precocious puberty.

The incidence of central precocious puberty (CPP) in boys is rising, but lack of effective molecular biomarkers often leads to delayed treatment and thus the terrible clinical complications in adulthood. This study aims to identify the specific-biomarkers of CPP boys and understand the gender-related differences in metabolic characteristics of CPP. The specific-biomarkers of CPP boys were identified from serum by cross-metabolomics combined with linear discriminant analysis effect size analysis after age correction, and union receiver operating characteristic curve analyses were perform to optimize the combination of specific-biomarkers. The differences in metabolic characteristics between boys and girls with CPP were explored by cross-metabolomics and weighted gene co-expression network analysis. Results show that CPP activated in advance the HPG axis and induced gender-related clinical phenotypes. Seven serum metabolites were identified as specific-biomarkers of CPP boys, including acetoacetate, aspartate, choline, creatinine, myo-inositol, N,N-dimethylglycine and N-Acetyl-glycoprotein. The combination of aspartate, choline, myo-inositol and creatinine achieved an optimized diagnosis, where AUC is 0.949, prediction accuracy for CPP boys is 91.1%, and the average accuracy is 0.865. The metabolic disorders of CPP boys mainly involve in glycerophospholipid metabolism, and synthesis and degradation of ketone bodies. Betaine, glutamine, isoleucine, lactate, leucine, lysine, pyruvate, α-&ß-glucose were identified as gender-related biomarkers for CPP, and they are mainly involved in glycolysis/gluconeogenesis, pyruvate metabolism, and alanine, aspartate and glutamate metabolism. Biomarkers combination provides a promising diagnostic potential for CPP boy with a favorite sensitivity and specificity. In addition, the differences of metabolic characteristics between boys and girls with CPP will contribute to the development of individualized clinical treatments in CPP.

Metabolomic analyses redefine the biological classification of pancreatic cancer and correlate with clinical outcomes.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by high heterogeneity, and the postoperative prognosis of different patients often varies greatly. Therefore, the classification of pancreatic cancer patients and precise treatment becomes particularly important. In our study, 1 H NMR spectroscopy was used to analyze the 76 PDAC serum samples and identify the potential metabolic subtypes. The metabolic characteristics of each metabolic subtype were screened out and the relationship between metabolic subtype and the long-term prognosis was further identified. The clinical stages of PDAC did not show the metabolic differences at the serum metabolomic level. And three metabolic subtypes, basic, choline-like and amino acid-enriched types, were defined by the hierarchical cluster analysis of the serum metabolites and the disturbed metabolic pathways. The characteristic metabolites of each PDAC subtype were identified, and the metabolite model was established to distinguish the PDAC patients in the different subtypes. Among the three metabolic subtypes, choline-like type displayed better long-term prognosis compared to the other two types of patients. Metabolic subtypes are of clinical importance and are closer to expressing the heterogeneity in the actual life activities of pancreatic cancer than molecular typing. The excavation of metabolic subtypes based on this will be more in line with clinical reality and more promising to guide clinical precision individualization treatment.

Composition Profiling and Authenticity Assessment of Camellia Oil Using High Field and Low Field 1H NMR.

Camellia oil (CA), mainly produced in southern China, has always been called Oriental olive oil (OL) due to its similar physicochemical properties to OL. The high nutritional value and high selling price of CA make mixing it with other low-quality oils prevalent, in order to make huge profits. In this paper, the transverse relaxation time (T2) distribution of different brands of CA and OL, and the variation in transverse relaxation parameters when adulterated with corn oil (CO), were assessed via low field nuclear magnetic resonance (LF-NMR) imagery. The nutritional compositions of CA and OL and their quality indices were obtained via high field NMR (HF-NMR) spectroscopy. The results show that the fatty acid evaluation indices values, including for squalene, oleic acid, linolenic acid and iodine, were higher in CA than in OL, indicating the nutritional value of CA. The adulterated CA with a content of CO more than 20% can be correctly identified by principal component analysis or partial least squares discriminant analysis, and the blended oils could be successfully classified by orthogonal partial least squares discriminant analysis, with an accuracy of 100% when the adulteration ratio was above 30%. These results indicate the practicability of LF-NMR in the rapid screening of food authenticity.

Chemotherapeutic efficacy of cucurmosin for pancreatic cancer as an alternative of gemcitabine: a comparative metabolomic study.

BACKGROUND: As the preferred drug for single chemotherapeutic application in pancreatic cancer, gemcitabine often demonstrated low sensitivity and strong chemotherapy resistance in patients. Therefore, the search for other drugs with high efficiency and low side effects has become of high importance. The aim of this study was to assess the therapeutic effects of cucurmosin on pancreatic cancer as an alternative of gemcitabine and explore its underlying biochemical mechanism. METHODS: The subcutaneous xenograft mice with pancreatic cancer were treated by high- and low-dose cucurmosin and gemcitabine, respectively. A comparative metabolomic analysis was performed on the serum samples from the different groups by 1H nuclear magnetic resonance (NMR) techniques and then subjected to univariate and multivariate statistical analysis. RESULTS: Cucurmosin demonstrated a dose-dependent inhibition to the pancreatic tumors. High-dose cucurmosin provided similar chemotherapeutic efficacy with gemcitabine by positively regulating pyruvate metabolism, glycolysis or gluconeogenesis, and cysteine and methionine metabolism. Inactivating GFR signaling pathway and further inducing apoptosis of tumor cells are the important mechanism of anti-tumor function of cucurmosin. CONCLUSIONS: Cucurmosin is a promising chemotherapeutic drug for pancreatic cancer. However, the dose selection and surface modification should be optimized according to the stage of pancreatic cancer, and an expanded study in both laboratory and clinical regimes needs to be performed.

Understanding metabolomic characteristics of pancreatic ductal adenocarcinoma by HR-MAS NMR detection of pancreatic tissues.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal carcinomas due to an inefficient early diagnosis and a disastrous prognosis. High resolution magic angle spinning nuclear magnetic resonance (HR-MAS NMR) detection of pancreatic tissues would facilitate the understanding of metabolomic characteristics of PDAC and further its clinical diagnosis by in vivo magnetic resonance spectroscopy (MRS). Pancreatic tissues from PDAC patients and Sprague-Dawley (SD) rats model and corresponding controls were detected and comparatively analyzed with HR-MAS NMR-based metabolomic strategy in order to get the underlying biomechanism and diagnostic information of PDAC. According to the univariate and multivariate statistical analysis, eight shared characteristic metabolites by PDAC patients and rats, including glycerophosphocholine (GPC), lactate, myo-inositol, methanol, taurine, methylene of lipid (L-CH2), ß-glucose and phosphocholine (PC), were identified as potential biomarkers of PDAC. Especially, GPC, PC and myo-inositol demonstrated high levels in pancreatic tissue and kept consistent metabolic changes both in PDAC patients and rat models. The occurrence of PDAC mainly involved the aberrations in glycerophospholipid metabolism, galactose metabolism and taurine and hypotaurine metabolism. As an in vitro alternative technique of in vivo MRS, HR-MAS NMR provided good resolution and sensitivity, thus underpinning a potential translation to the in vivo MRS setting for noninvasive detection and monitoring of clinical PDAC. The metabolic differences caused in the different species not only enhance the understanding of metabolic reprogramming of PDAC but also promote the intercommunication of PDAC metabolomes between the different species.

Specific biological responses following dextran-coated ultra-small superparamagnetic particles of iron oxides administration.

Aim: The potential bio-related risks of dextran-coated ultra-small superparamagnetic particles of iron oxides (D-USPIO) were assessed. Materials & methods: Metabolic responses of D-USPIO in BALB/C mice were obtained using 1H-NMR-based metabolomic strategy combined with the traditional biochemical assay. Results: The metabolomic analyses of biological fluids (plasma and urine) and organs (liver, kidney and spleen) indicated that the disturbance, impairment and recovery of the physiological functions were related to the metabolic response to D-USPIO. The correlations between the biofluids and tissue metabolomes described the specific metabolic information of D-USPIO on their in vivo transportation, absorption, biodistribution and excretion. Conclusion: Metabolomic analysis provides preliminary validation for the use of D-USPIO in clinical medicine, and the results help to understand the potential adverse effects of the similar bio-nanomaterials further serve to their synthesis optimization and biocompatibility improvement.

Revealing Different Lung Metastatic Potentials Induced Metabolic Alterations of Hepatocellular Carcinoma Cells via Proton Nuclear Magnetic Resonance Spectroscopy.

Background: Hepatocellular carcinoma (HCC) causes death mainly by disseminated metastasis progression and major challenge of clinical management is to distinguish lethal metastatic stage from indolent stage. It is shown that metastatic progression is closely related to cellular metabolism. But detailed metabolic alterations and molecular mechanisms still kept unclear between subtypes of different lung metastatic potentials. Methods: The current work used NMR-based metabolomics in the study of HCC cells with high malignancy but differed in lung metastatic potentials. Cell extracts and cultured media from MHCC97L and MHCC97H were utilized to reveal metabolic alterations related to metastatic potentials. Multivariate analyses were performed to identify characteristic metabolites which were used subsequently to draw the map of relative biochemical pathways by combining KEGG database. Results: The NMR spectra of both MHCC97L and MHCC97H include various signals from necessary nutritional components and metabolic intermediates. A series of characteristic metabolites were determined from both cell extracts and media. The ability on nutrient uptake varied from cell lines. Most of amino acids decreased in high metastatic cell line, so altered amino acid metabolisms and energy metabolism were revealed in high metastatic MHCC97H cell line. The majority pathways involved six essential amino acids in which the observed branched-chain amino acids together with lysine contributed to biosynthesis or degradation. Basically MHCC97H cell line could induce more active events than that of MHCC97L to progress to high metastasis with certain molecular events. Characteristic metabolites-derived classifiers performed robustly during prediction and confirmed their critical role in supporting metastasis progression. Conclusions: Our results provide evidence that NMR-metabolomics analyses of cells are able to understand metastatic characteristics accountable for biological properties. The proposed characteristic metabolites will help to understand HCC metastatic characterizations and may be filtered as potential biomarkers.

Metabolic profiling of normal hepatocyte and hepatocellular carcinoma cells via 1 H nuclear magnetic resonance spectroscopy.

Hepatocellular carcinoma (HCC) causes death mainly by disseminated metastasis progression from the organ being confined. Different metastatic stages are closely related to cellular metabolic profiles. Normal hepatocyte and HepG2 cell line from low metastatic HCC were studied by NMR-based metabolomic techniques. Multivariate and univariate statistical analyses were utilized to identify characteristic metabolites from cells and cultured media. Elevated levels of acetate, creatine, isoleucine, leucine, and phenylalanine were observed in HepG2 cells, suggesting more active in gathering nutrient components along with altered amino acid metabolisms and enhanced lipid metabolism. High glucose consumption was significantly different in low metastatic cells. A series of characteristic metabolites were identified and served as biomarkers. Relative metabolic pathway analysis shows that low metastatic HepG2 cell line exhibits active behaviors in metabolisms and biosynthesis of specific amino acids and energy metabolism. Moreover, characteristic metabolites-based classification models executed by support vector machines algorithm perform robustly to classify normal hepatocyte and HepG2 cell line. It is concluded that NMR-based metabolomic analyses of cell lines can provide a powerful approach to understand metastasis-related biological alterations. The present study also provides a basis for metabolic markers determination of hepatic carcinoma in the future clinical study.

Non-invasively predicting differentiation of pancreatic cancer through comparative serum metabonomic profiling.

BACKGROUND: The differentiation of pancreatic ductal adenocarcinoma (PDAC) could be associated with prognosis and may influence the choices of clinical management. No applicable methods could reliably predict the tumor differentiation preoperatively. Thus, the aim of this study was to compare the metabonomic profiling of pancreatic ductal adenocarcinoma with different differentiations and assess the feasibility of predicting tumor differentiations through metabonomic strategy based on nuclear magnetic resonance spectroscopy. METHODS: By implanting pancreatic cancer cell strains Panc-1, Bxpc-3 and SW1990 in nude mice in situ, we successfully established the orthotopic xenograft models of PDAC with different differentiations. The metabonomic profiling of serum from different PDAC was achieved and analyzed by using 1H nuclear magnetic resonance (NMR) spectroscopy combined with the multivariate statistical analysis. Then, the differential metabolites acquired were used for enrichment analysis of metabolic pathways to get a deep insight. RESULTS: An obvious metabonomic difference was demonstrated between all groups and the pattern recognition models were established successfully. The higher concentrations of amino acids, glycolytic and glutaminolytic participators in SW1990 and choline-contain metabolites in Panc-1 relative to other PDAC cells were demonstrated, which may be served as potential indicators for tumor differentiation. The metabolic pathways and differential metabolites identified in current study may be associated with specific pathways such as serine-glycine-one-carbon and glutaminolytic pathways, which can regulate tumorous proliferation and epigenetic regulation. CONCLUSION: The NMR-based metabonomic strategy may be served as a non-invasive detection method for predicting tumor differentiation preoperatively.

Identification and causes of metabonomic difference between orthotopic and subcutaneous xenograft of pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal tumors. However, the methodological differences between orthotopic and subcutaneous xenograft (OX and SX) models will cause confusion in understanding its pathological mechanism and clinical relevance. In this study, SX and OX models were established by implanting Panc-1 and BxPC-3 cell strains under skin and on the pancreas of mice, respectively. The tumor tissue and serum samples were collected for1H NMR spectroscopy followed by univariate and multivariate statistical analyses. As results, no obvious metabonomic difference was demonstrated in serum between the two models, however, the model- and cell strain-specific metabonomic differences were observed in tumor tissues. According to the KEGG analysis, ABC transporters, glycerophospholipid metabolism, purine metabolism and central carbon metabolism were identified to be the most significant components involved in metabonomic differences. Considering the methodological discrepancy in SX and OX models, such differences should be contributed to tumor microenvironment. In general, SX are not equivalent to OX models at molecular level. Subcutaneous transplantation displayed its inherent limitations though it offered a simple, inexpensive, reproducible and quantifiable advantage. And orthotopic transplantation may be favorable to simulate PDAC in patients due to its similar pathogenesis to human pancreatic cancer.

Metabonomic alterations from pancreatic intraepithelial neoplasia to pancreatic ductal adenocarcinoma facilitate the identification of biomarkers in serum for early diagnosis of pancreatic cancer.

Pancreatic cancer is a highly malignant disease with a poor prognosis and it is essential to diagnose and treat the disease at an early stage. The aim of this study was to understand the underlying biochemical mechanisms of pancreatic intraepithelial neoplasia (PanIN) and pancreatic ductal adenocarcinoma (PDAC) and to identify potential serum biomarkers for early detection of pancreatic cancer. 7,12-Dimethylbenz(a)anthracene (DMBA)-induced PanIN and PDAC rat models were established and the serum samples were collected. The serum samples were measured using (1)H nuclear magnetic resonance (NMR) spectroscopy and analyzed by chemometric methods including principal component analysis (PCA) and (orthogonal) partial least squares discriminant analysis ((O)PLS-DA). The related biochemical pathways were derived from KEGG analysis of the significantly different metabolites. As results, some serum metabolites demonstrated alarming metabolic changes in the precursor lesion of pancreatic cancer (PanIN-2 in this study). These changes involved elevated levels of ketone compounds including 3-hydroxybutyrate, acetoacetate, and acetone, some amino acids including asparagine, glutamate, threonine, and phenylalanine, glycoproteins and lipoproteins including N-acetylglycoprotein, LDL and VLDL, and some metabolites that have been shown to contribute to mutagenicity and cancer promotion such as deoxyguanosine and cytidine. More metabolites were shown to be significantly different between PanIN and PDAC, suggesting that a more complex set of changes occurs from noninvasive precursor lesion to invasive cancer. The serum metabonomic changes of rats with PanIN and PDAC may extend our understanding of pancreatic molecular pathogenesis, and the metabolic variations from PanIN to PDAC will be helpful to understand evolution processes of the pancreatic disease. NMR-based metabonomic analysis of animal models will be beneficial for the human study and will be helpful for the early detection of pancreatic cancer.

Plasma metabolomic analysis of human hepatocellular carcinoma: Diagnostic and therapeutic study.

Many hepatocellular carcinoma (HCC) patients suffer from late stages when diagnosed, leading to dismal prospects for cure. Improving the diagnosis and treatment of HCC remains a challenge. In this work, NMR-based metabolomic techniques were used to investigate the metabolic alterations of HCC patients from different pathological backgrounds. Metabolic improvement of clinical surgical treatments or transcatheter arterial chemoembolization (TACE) for recurrent or metastatic HCC was also evaluated. HCC was characterized by enhanced lipid metabolism and high consumption in response to liver injury. Expectedly, higher consumption of glucose and lactate production in TACE group confirmed that recurrent or metastatic HCC is more active in citric acid cycle and oxidative phosphorylation. However, TACE or surgical treatments did not immediately improve the metabolic profiles of HCC patients. Combining multivariate statistical analyses with univariate t-test, a series of characteristic metabolites were identified and served as biomarkers for discrimination of HCC patients in different pathological backgrounds. The relative metabolic pathway analyses help to get insight into the underlying biochemical mechanism and extend clinical relevance. Furthermore, algorithm of support vector classification was used to identify HCC and control subjects, and diagnostic sensitivity and specificity reached to 100% and 81.08% respectively by receiver operating characteristic analysis. It is concluded that NMR-based metabolomic analysis of plasma can provide a powerful approach to discover diagnostic and therapeutic biomarkers, and subsequently contribute to clinical disease management.

Metabonomic changes from pancreatic intraepithelial neoplasia to pancreatic ductal adenocarcinoma in tissues from rats.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most malignant tumors and is difficult to diagnose in the early phase. This study was aimed at obtaining the metabolic profiles and characteristic metabolites of pancreatic intraepithelial neoplasia (PanIN) and PDAC tissues from Sprague-Dawley (SD) rats to establish metabonomic methods used in the early diagnosis of PDAC. In the present study, the animal models were established by embedding 7,12-dimethylbenzanthracene (DMBA) in the pancreas of SD rats to obtain PanIN and PDAC tissues. After the preprocessing of tissues, (1) H nuclear magnetic resonance (NMR) spectroscopy combined with multivariate and univariate statistical analysis was applied to identify the potential metabolic signatures and the corresponding metabolic pathways. Pattern recognition models were successfully established and differential metabolites, including glucose, amino acids, carboxylic acids and coenzymes, were screened out. Compared with the control, the trends in the variation of several metabolites were similar in both PanIN and PDAC. Kynurenate and methionine levels were elevated in PanIN but decreased in PDAC, thus, could served as biomarkers to distinguish PanIN from PDAC. Our results suggest that NMR-based techniques combined with multivariate statistical analysis can distinguish the metabolic differences among PanIN, PDAC and normal tissues, and, therefore, present a promising approach for physiopathologic metabolism investigations and early diagnoses of PDAC.

1H NMR-based metabolomics study on the physiological variations during the rat pregnancy process.

In this study, NMR-based metabolomics in combination with multivariate pattern recognition technologies were employed to evaluate the physiological variations in the Wistar rats' plasma that are induced by pregnancy on the gestational days (GDs) 11, 14, 17 and 20. Untargeted metabolomics analysis revealed some possible mechanism of physiological effects for healthy pregnancies and showed a metabolic trajectory during pregnancy process. The levels of 24 metabolites were found to change significantly throughout pregnancy in maternal plasma. These metabolite changes involved in varied kinds of metabolic pathways including synthesis of biological substances, microbial metabolism in diverse environments, protein digestion and absorption, carbohydrate metabolism, digestion and absorption, mineral absorption, and ATP (Adenosine Triphosphate)-binding cassette transporters (ABC transporters). The substantial cores of all the metabolic pathways are promoting fetal growth and development and regulating maternal physiological state. This work showed relevant metabolic pathways perturbation in the maternal plasma due to normal pregnancy and provided the physical basis of time-dependent metabolic trajectory against which disease-related maternal physiological responses may be better understood in future studies.

Maternal and fetal metabonomic alterations in prenatal nicotine exposure-induced rat intrauterine growth retardation.

Prenatal nicotine exposure causes adverse birth outcome. However, the corresponding metabonomic alterations and underlying mechanisms of nicotine-induced developmental toxicity remain unclear. The aims of this study were to characterize the metabolic alterations in biofluids in nicotine-induced intrauterine growth retardation (IUGR) rat model. In the present study, pregnant Wistar rats were intragastrically administered with different doses of nicotine (0.5, 1.0 and 2.0 mg/kg d) from gestational day (GD) 11-20. The metabolic profiles of the biofluids, including maternal plasma, fetal plasma and amniotic fluid, were analyzed using (1)H nuclear magnetic resonance (NMR)-based metabonomic techniques. Prenatal nicotine exposure caused noticeably lower body weights, higher IUGR rates of fetal rats, and elevated maternal and fetal corticosterone (CORT) levels compared to the controls. The correlation analysis among maternal, fetal serum CORT levels and fetal bodyweight suggested that the levels of maternal and fetal serum CORT presented a positive correlation (r=0.356, n=32, P<0.05), while there was a negative correlation between fetal (r=-0.639, n=32, P<0.01) and maternal (r=-0.530, n=32, P<0.01) serum CORT level and fetal bodyweight. The fetal metabonome alterations included the stimulation of lipogenesis and the decreased levels of glucose and amino acids. The maternal metabonome alterations involved the enhanced blood glucose levels, fatty acid oxygenolysis, proteolysis and amino acid accumulation. These results suggested that prenatal nicotine exposure is associated with an altered maternal and fetal metabonome, which may be related to maternal increased glucocorticoid level induced by nicotine.

An insight into the metabolic responses of ultra-small superparamagnetic particles of iron oxide using metabonomic analysis of biofluids.

Ultra-small superparamagnetic particles of iron oxides (USPIO) have been developed as intravenous organ/tissue-targeted contrast agents to improve magnetic resonance imaging (MRI) in vivo. However, their potential toxicity and effects on metabolism have attracted particular attention. In the present study, uncoated and dextran-coated USPIO were investigated by analyzing both rat urine and plasma metabonomes using high-resolution NMR-based metabonomic analysis in combination with multivariate statistical analysis. The wealth of information gathered on the metabolic profiles from rat urine and plasma has revealed subtle metabolic changes in response to USPIO administration. The metabolic changes include the elevation of urinary alpha-hydroxy-n-valerate, o- and p-HPA, PAG, nicotinate and hippurate accompanied by decreases in the levels of urinary alpha-ketoglutarate, succinate, citrate, N-methylnicotinamide, NAG, DMA, allantoin and acetate following USPIO administration. The changes associated with USPIO administration included a gradual increase in plasma glucose, N-acetyl glycoprotein, saturated fatty acid, citrate, succinate, acetate, GPC, ketone bodies (beta-hydroxybutyrate, acetone and acetoacetate) and individual amino acids, such as phenylalanine, lysine, isoleucine, glycine, glutamine and glutamate and a gradual decrease of myo-inositol, unsaturated fatty acid and triacylglycerol. Hence USPIO administration effects are reflected in changes in a number of metabolic pathways including energy, lipid, glucose and amino acid metabolism. The size- and surface chemistry-dependent metabolic responses and possible toxicity were observed using NMR analysis of biofluids. These changes may be attributed to the disturbances of hepatic, renal and cardiac functions following USPIO administrations. The potential biotoxicity can be derived from metabonomic analysis and serum biochemistry analysis. Metabonomic strategy offers a promising approach for the detection of subtle physiological responses on mammalian metabolism, and can be employed to investigate the potential adverse effects of other nanoparticles and nanomaterials on the environment and human health.

Tuftsin derivatives of FITC, Tb-DOTA or Gd-DOTA as potential macrophage-specific imaging biomarkers.

Fluorescein- and terbium-labelled tuftsin (Thr-Lys-Pro-Arg) and pentapeptide (Thr-Lys-Pro-Pro-Arg) were synthesized and their properties were evaluated in vitro by luminescence spectrometry and confocal microscopy as fluorescence probes to target macrophage cells in biological systems. An increase in fluorescence of macrophages incubated with varying concentrations of fluorescein isothiocyanate or Tb-DOTA-tuftsin/pentapeptide conjugates was observed in a concentration-dependent manner. Tb-DOTA-pentapeptide had a greater affinity to macrophages than Tb-DOTA-tuftsin. Lipopolysaccharide (LPS) stimulation strengthened the internalization of peptide conjugates by macrophages through the tuftsin receptor mechanism. Tb-DOTA-tuftsin/pentapeptide conjugates are likely to be a promising optical reagents as probes of the immune response with involvement of macrophage cells in a variety of diseases. Gd-DOTA-tuftsin conjugate was also evaluated as a cell-specific contrast agent in in vitro MRI experiments. In this context, the macrophages labelled by Gd-DOTA-tuftsin were highly magnetic and detectable by MRI, which confirms that this vectorized MRI probe has the potential to image macrophage-mediated inflammation in diseases like brain traumas and stroke. Tuftsin receptor-specific biological-function domain may have a modified in vivo biodistribution profile, bioavailability and pharmacokinetics subsequent to its conjugation to a metal ion-binding backbone.