[Quantitative metabolomics based on NMR].

Nuclear magnetic resonance (NMR) spectroscopy can be used to both identify and quantify chemicals from complex mixtures. Over the last several decades, significant technical and experimental advances have made quantitative nuclear magnetic resonance (qNMR) a valuable analytical tool for quantitative measurements of a wide variety of samples. This particular approach is now being exploited to characterize the metabolomes of many different biological samples and is called quantitative metabolomics or targeted metabolic profiling. In this review, some of the strengths, limitations of NMR-based quantitative metabolomics will be discussed as well as the practical considerations necessary for acquisition with an emphasis on their use for bioanalysis. Recent examples of the application of this particular approach to metabolomics studies will be also presented.

Evaluation of dose-related effects of 2', 3', 5'-tri-O-acetyl-N6-(3-hydroxylaniline)adenosine using NMR-based metabolomics.

2', 3', 5'-Tri-O-acetyl-N6-(3-hydroxylaniline)adenosine (WS070117) is a derivative compound of natural product cordycepin. It has significant lipids regulating activity and low toxicity which has been proved by in vitro and in vivo experiments. In this study, 1H NMR-based metabolomics was used to investigate the dose-related effects of WS070117 on hyperlipidemia of high-fat-fed hamsters. The hyperlipidemic hamsters were administrated with six different doses of WS070117, including 3, 12, 50, 100, 200 and 400 mg x kg(-1) x d(-1). 1H NMR spectra of hamster serum were visually and statistically analyzed using two multivariate analyses: principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA). As a result, WS070117-treated groups showed dose-related regulation of metabolites associated with lipid metabolism, choline metabolism and glucose metabolism. The dose of 3 mg x kg(-1) x d(-1) of WS070117 only exhibited a little lipids regulating activity. However, the doses of 12 and 50 mg x kg(-1) x d(-1) of WS070117 both regulated the contents of metabolites to reverse significantly toward normal levels. When the dose of WS070117 reached 100 mg x kg(-1) x d(-1), it was more effective than positive control drugs. The work suggested that NMR-based metabolomics might be a valuable approach to evaluate dose-related effects of lipids regulating compounds.

[A 1H NMR based metabonomics approach to progression of coronary atherosclerosis in a hamster model].

To obtain a better understanding of the progression of atherosclerosis and identify potential biomarkers, proton nuclear magnetic resonance spectroscopy (1H NMR)-based metabonomics was used to study the metabolic changes in the plasma of hamster fed with a high-fat/cholesterol diet. Plasma samples were collected at different time points during the progression of atherosclerosis and individual proton NMR spectra were visually and statistically assessed using multivariate analyses. NMR results for all samples showed a time-dependent development from physiological to pathophysiological status during atherosclerosis. Analysis of the identified biomarkers of atherosclerosis suggests that lipid and amino acid metabolisms are significantly disturbed, together with inflammation, oxidative stress, following cholesterol overloading. The results enriched our understanding of the mechanism of atherosclerosis and demonstrated the effectiveness of the NMR-based metabonomics approach to study such a complex disease.

Downregulation of ornithine decarboxylase by pcDNA-ODCr inhibits gastric cancer cell growth in vitro.

Ornithine decarboxylase (ODC), the first rate-limiting enzyme of polyamine biosynthesis, was found to be associated with cell growth, proliferation and transformation. ODC gene expression in gastric cancer was increased and its level was positively correlated with the degree of malignity of gastric mucosa and development of gastric lesions. In order to evaluate the therapeutic effects of antisense RNA of ODC on gastric cancer, an antisense RNA of ODC expressing plasmid pcDNA-ODCr which delivered a 120 bp fragment complementary to the initiation codon of ODC gene was constructed and transfected to gastric cancer cells SGC7901 and MGC803. Expression of ODC in gastric cancer cells was determined by western blot. Cell proliferation was assessed by MTS assay. Cell cycle was analyzed by flow cytometry and Matrigel assay was performed to assess the ability of gastric cancer cell invasiveness. The results showed that the ODC gene expression in gastric cancer cells transfected with the pcDNA-ODCr was downregulated efficiently. Tumor cell proliferation was suppressed significantly, and cell cycle was arrested at G1 phase. Gastric cancer cells had reduced invasiveness after gene transfer. Our study suggested that antisense RNA of ODC expressing plasmid pcDNA-ODCr had antitumor activity by inhibiting the expression of ODC, and downregulation of ODC expression using a gene therapy approach might be a novel therapeutic strategy for gastric cancer.

RNA interference-mediated silencing of UBCH10 gene inhibits colorectal cancer cell growth in vitro and in vivo.

1. UbcH10 is the cancer-related E2 ubiquitin-conjugating enzyme, and its overexpression has been demonstrated in a variety of malignancies. The aim of the present study is to silence UbcH10 gene by RNA interference (RNAi) and to observe its inhibitory effect on the colorectal cancer cell growth in vitro and in vivo. 2. We constructed the expression vector pGPU6/GFP/Neo/UbcH10-RNAi (pUbcH10-RNAi), which contained a UbcH10 short hairpin RNA expression cassette. Then the UbcH10 gene silencing cell lines LoVo/UbcH10-RNAi and HT-29/UbcH10-RNAi were established. Reverse transcription-polymerase chain reaction and western blot analysis were used to evaluate the expression of the UbcH10 gene. Cell Counting Kit-8 was used to assess properties of tumour cell growth in vitro. Flow cytometry was used to detect the effect of pUbcH10-RNAi on the cell cycle of colorectal cancer cells. Furthermore, the anti-tumour effects of pUbcH10-RNAi were evaluated in vivo in a nude mouse xenografts model. 3. Results demonstrated that UbcH10 gene expression was significantly decreased in pUbcH10-RNAi treated cells. Colorectal cancer cells growth was markedly suppressed in the pUbcH10-RNAi group compared with control conditions and colorectal cancer cells were arrested in the G2-M phase. In vivo, the downregulation of UbcH10 gene expression by pUbcH10-RNAi also inhibited tumour growth in a nude mice xenograft model. 4. Our study suggests that RNA interference-mediated silencing of UbcH10 gene has anti-tumour activity on colorectal cancer and might have therapeutic potential for the treatment of colorectal cancer.

Effect of ticagrelor on the serum level of hs-CRP, ESM-1 and short-term prognosis of patients with acute STEMI.

The aim of the present study was to observe and investigate the changes in the serum level of high-sensitivity C-reactive protein (hs-CRP), the endothelial cell-specific molecule-1 (ESM-1) and short-term prognosis of patients with ST-segment elevation myocardial infarction (STEMI) treated by ticagrelor. We enrolled 107 patients with acute STEMI who were admitted in the Department of Cardiology for the first time with occurrence of symptoms, and we successfully performed emergency operation of percutaneous coronary intervention. The patients were divided into two groups, 54 patients in the ticagrelor group (treatment group) and 53 patients in the clopidogrel group (control group), according to the administration of ticagrelor or clopidogrel in dual anti-platelet therapy. Then, we observed the changes at the time of admission, at 24 h, and 4th and 7th day after administration and investigated the correlations between them and the effect of ticagrelor on the short-term prognosis of acute STEMI patients. Significant increases of the serum levels of hs-CRP and ESM-1 were seen in patients of the two groups 24 h after administration of drugs with statistically significant differences between the groups (P<0.05), and on the 4th and 7th day we found a downward trend with statistically significant differences (P<0.05). The level of ESM-1 enhanced the increase of hs-CRP, indicating there was a positive correlation between ESM-1 and hs-CRP (r=0.535, P<0.001). A comparison of the occurrence rates of ischemic outcome event, bleeding and overall adverse events between the two groups yielded no statistically significant difference (P>0.05). In conclusion, the present study demonstrates that ticagrelor can reduce the prevalence of inflammatory reactions rapidly and stabilize the functions of vascular endothelium to improve the stability of atherosclerosis plaque and decrease the occurrence rate of thrombosis as well as ischemic outcome event without any obvious increase in the risk of bleeding. Thus, ticagrelor should be recommended in clinical practices for the treatment of patients with STEMI.

Keratopathy due to ophthalmic drug abuse with corneal melting and perforation presenting as Mooren-like ulcer: A case report.

The present report describes the clinical course and treatment of a Mooren-like ulcer associated with abuse of topical anesthetics and dexamethasone. A 38-year-old male physician treated himself with lidocaine, tetracaine and dexamethasone (DEX) eye drops for severe pain and decline of vision in both eyes. After six months of treatment, his right cornea exhibited annular melting with full-thickness stromal infiltration at the limbus and central corneal haze. His left cornea was completely melted and exhibited iris prolapse. The patient was treated with topical antibiotics, lubricants and underwent a binocular keratoplasty. The surgery was successful and after eight months the postoperative best-corrected visual acuities were counting fingers in the right eye and light perception in the left eye. In summary, this report documents a severe case of keratopathy presenting as Mooren-like ulcer caused by topical anesthetics and DEX, which were treated via keratoplasty, resulting in useful vision being retained.

Effects of the short-term application of pantoprazole combined with aspirin and clopidogrel in the treatment of acute STEMI.

The aim of the present study was to determine the effects of the short-term application of pantoprazole on the co-treatment of acute ST-segment elevation myocardial infarction (STEMI) with aspirin and clopidogrel. A total of 207 acute patients showing primary symptoms of STEMI, who received successful emergent percutaneous coronary intervention treatment during hospitalization were randomly divided into two groups. In the test group proton pump inhibitors (PPIs), the patients were treated with a combination of aspirin and clopidogrel and pantoprazole, while those in the control group were treated only with aspirin and clopidogrel. Gastrointestinal bleeding events and major adverse cardiac events (MACEs) were observed in the two groups. Gastrointestinal bleeding events of the two groups mostly occurred within the first week of hospitalization, although the incidence in the PPIs group was significantly higher than that in the control group (p<0.05). However, no significant difference was observed for the incidence of MACEs between the two groups (p>0.05). In conclusion, the results of the present study have shown that the short-term application of pantoprazole combined with aspirin and clopidogrel does not increase the incidence of MACEs in patients with acute STEMI, reduces the risk of gastrointestinal bleeding, and is thus worth promoting clinically, particularly for high-risk groups.

Ornithine decarboxylase gene is overexpressed in colorectal carcinoma.

AIM: To investigate the ornithine decarboxylase (ODC) gene expression in colorectal carcinoma, ODC mRNA was assayed by RT-PCR and ODC protein was detected by a monoclonal antibody against fusion of human colon ODC prepared by hybridoma technology. METHODS: Total RNA was extracted from human colorectal cancer tissues and their normal counterpart tissues. ODC mRNA levels were examined by RT-PCR. ODC genes amplified from RT-PCR were cloned into a prokaryotic vector pQE-30. The expressed proteins were purified by chromatography. Anti-ODC mAb was prepared with classical hybridoma techniques and used to determine the ODC expression in colon cancer tissues by immunohistochemical and Western blotting assay. RESULTS: A cell line, which could steadily secrete anti-ODC mAb, was selected through subcloning four times. Western blotting reconfirmed the mAb and ELISA showed that its subtype was IgG2a. RT-PCR showed that the ODC mRNA level increased greatly in colon cancer tissues (P<0.01). Immunohistochemical staining showed that colorectal carcinoma cells expressed a significantly higher level of ODC than normal colorectal mucosa (98.6+/-1.03% vs 5.26+/-5%, P<0.01). CONCLUSION: ODC gene overexpression is significantly related to human colorectal carcinoma. ODC gene expression may be a marker for the gene diagnosis and therapy of colorectal carcinoma.

Intermedin attenuates myocardial infarction through activation of autophagy in a rat model of ischemic heart failure via both cAMP and MAPK/ERK1/2 pathways.

Intermedin is a proopiomelanocortin-derived peptide before opioid promoting cortical hormone, its main function embodies in mononuclear macrophages and neutrophilic granulocytes to inhibit the proinflammatory cytokines. The aim of this study is to determine intermedin attenuates myocardial infarction and its related mechanisms in a rat model of ischemic heart failure. After rat model of ischemic heart failure was set up, myocardial infarction, blood levels of activities of creatine kinase (CK), the MB isoenzyme of creatine kinase (CK-MB), lactate dehydrogenase (LDH) and cardiac troponin T (cTnT) were effectively reduced by treatment with intermedin. Tumor necrosis factor (TNF-α) and interleukin-6 (IL-6) in a rat model of ischemic heart failure were recovered by pretreatment with intermedin. Administrate of intermedin availably promoted cAMP contents and suppressed caspase-3 protein in ischemic heart failure rat. ERK1/2 and LC3 protein expression were significantly activated and autophagy was significantly promoted by intermedin in a rat model of ischemic heart failure. These results indicate that intermedin protected rat heart, attenuates myocardial infarction from ischemic heart failure in the rat model. The underlying mechanisms may include upregulation of cAMP, ERK1/2 and LC3 protein expression and activating of autophagy.

Cloning and expression of ornithine decarboxylase gene from human colorectal carcinoma.

AIM: To construct and express ODC recombinant gene for further exploring its potential use in early diagnosis of colorectal carcinoma. METHODS: Total RNA was extracted from colon cancer tissues and amplified by reverse-transcription PCR with two primers, which span the whole coding region of ODC. The synthesized ODC cDNA was cloned into vector pQE-30 at restriction sites BamH I and Sal I which constituted recombinant expression plasmid pQE30-ODC. The sequence of inserted fragment was confirmed by DNA sequencing, the fusion protein including 6His-tag was facilitated for purification by Ni-NTA chromatographic column. RESULTS: ODC expression vector was constructed and confirmed with restriction enzyme digestion and subsequent DNA sequencing. The DNA sequence matching on NCBI Blast showed 99 % affinity. The vector was transformed into E. coli M15 and expressed. The expressed ODC protein was verified with Western blotting. CONCLUSION: The ODC prokaryote expression vector is constructed and thus greatly facilitates to study the role of ODC in colorectal carcinoma.

A (1)H NMR-Based Metabonomic Investigation of Time-Related Metabolic Trajectories of the Plasma, Urine and Liver Extracts of Hyperlipidemic Hamsters.

The hamster has been previously found to be a suitable model to study the changes associated with diet-induced hyperlipidemia in humans. Traditionally, studies of hyperlipidemia utilize serum- or plasma-based biochemical assays and histopathological evaluation. However, unbiased metabonomic technologies have the potential to identify novel biomarkers of disease. Thus, to obtain a better understanding of the progression of hyperlipidemia and discover potential biomarkers, we have used a proton nuclear magnetic resonance spectroscopy ((1)H-NMR)-based metabonomics approach to study the metabolic changes occurring in the plasma, urine and liver extracts of hamsters fed a high-fat/high-cholesterol diet. Samples were collected at different time points during the progression of hyperlipidemia, and individual proton NMR spectra were visually and statistically assessed using two multivariate analyses (MVA): principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA). Using the commercial software package Chenomx NMR suite, 40 endogenous metabolites in the plasma, 80 in the urine and 60 in the water-soluble fraction of liver extracts were quantified. NMR analysis of all samples showed a time-dependent transition from a physiological to a pathophysiological state during the progression of hyperlipidemia. Analysis of the identified biomarkers of hyperlipidemia suggests that significant perturbations of lipid and amino acid metabolism, as well as inflammation, oxidative stress and changes in gut microbiota metabolites, occurred following cholesterol overloading. The results of this study substantially broaden the metabonomic coverage of hyperlipidemia, enhance our understanding of the mechanism of hyperlipidemia and demonstrate the effectiveness of the NMR-based metabonomics approach to study a complex disease.

Construction and application of a novel genetically engineered Aspergillus oryzae for expressing proteases

Background: We aimed to test the possibility of improving polypeptide production from soybean meal fermentation by engineered Aspergillus oryzae strains. Four different protease genes were cloned and transformed into wild-type A. oryzae, and the engineered A. oryzae strains were then used for soybean meal fermentation. Results: The results showed different degrees of improvement in the protease activity of the four transformants when compared with wild-type A. oryzae. A major improvement in the polypeptide yield was achieved when these strains were used in soybean meal fermentation. The polypeptide conversion rate of one of the four transformants, A. oryzae pep, reached 35.9%, which was approximately twofold higher than that exhibited by wild-type A. oryzae. Amino acid content analysis showed that the essential amino acid content and amino acid composition of the fermentation product significantly improved when engineered A. oryzae strains were used for soybean meal fermentation. Conclusions: These findings suggest that cloning of microbial protease genes with good physicochemical properties and expressing them in an ideal host such as A. oryzae is a novel strategy to enhance the value of soybean meal.

Expression of nesfatin-1/NUCB2 in rodent digestive system.

AIM: To observe the regional distributions and morphological features of nesfatin-1/nucleobindin-2 (NUCB2) immunoreactive (IR) cells in the rodent digestive system. METHODS: Paraffin-embedded sections of seven organs (pancreas, stomach, duodenum, esophagus, liver, small intestine and colon) dissected from sprague-dawley (SD) rats and imprinting-control-region (ICR) mice were prepared. The regional distributions of nesfatin-1/NUCB2 IR cells were observed by immunohistochemical staining. The morphological features of the nesfatin-1/NUCB2 IR cells were evaluated by hematoxylin and eosin (HE) staining. Fresh tissues of the seven organs were prepared for Western blotting to analyze the relative protein levels of NUCB2 in each organ. RESULTS: Immunohistochemical staining showed that the nesfatin-1/NUCB2 IR cells were localized in the central part of the pancreatic islets, the lower third and middle portion of the gastric mucosal gland, and the submucous layer of the duodenum in SD rats and ICR mice. HE staining revealed that the morphological features of nesfatin-1/NUCB2 IR cells were mainly islet cells in the pancreas, endocrine cells in the stomach, and Brunner's glands in the duodenum. Western blotting revealed that NUCB2 protein expression was higher in the pancreas, stomach and duodenum than in the esophagus, liver, small intestine and colon (P = 0.000). CONCLUSION: Nesfatin-1/NUCB2 IR cells are expressed in the pancreas, stomach and duodenum in rodents. These cells may play an important role in the physiological regulation of carbohydrate metabolism, gastrointestinal function and nutrient absorption.

Polyamine depletion by ODC-AdoMetDC antisense adenovirus impairs human colorectal cancer growth and invasion in vitro and in vivo.

BACKGROUND: Polyamine biosynthesis is controlled primarily by ornithine decarboxylase (ODC) and S-adenosylmethionine decarboxylase (AdoMetDC). Polyamine concentrations are elevated in colorectal cancer. Depletion of polyamine content in colorectal cancer by chemotherapy is related to tumor regression and impaired tumorigenicity. The current study evaluates the therapeutic effects of antisense ODC and AdoMetDC sequences on colorectal cancer in vitro and in vivo. METHODS: Antisense ODC and AdoMetDC sequences were cloned into an adenoviral vector (Ad-ODC-AdoMetDCas). The human colon cancer cell lines, HT-29 and Caco-2, were infected with Ad-ODC-AdoMetDCas as well as with control vector. Viable cell counting, determination of polyamine concentrations, cell cycle analysis, and Matrigel invasion assays were performed in order to assess properties of tumor growth and invasiveness. Furthermore, the antitumor effects of Ad-ODC-AdoMetDCas were also evaluated in vivo in a nude mouse tumor model. RESULTS: Our study demonstrated that adenovirus-mediated ODC and AdoMetDC antisense expression inhibits tumor cell growth through a blockade of the polyamine synthesis pathway. This inhibitory effect cannot be reversed by the administration of putrescine. Tumor cells were arrested at the G1 phase of the cell cycle after gene transfer and had reduced invasiveness. The adenovirus also induced tumor regression in established tumors in nude mice. CONCLUSIONS: Our study suggests that Ad-ODC-AdoMetDCas has antitumor activity and therapeutic potential for the treatment of colorectal cancer.

Adenovirus-mediated expression of both antisense ODC and AdoMetDC inhibited colorectal cancer cell growth in vitro.

AIM: To construct a recombinant adenovirus that can simultaneously express both antisense ornithine decarboxylase (ODC) and adenosylmethionine decarboxylase ( AdoMetDC ) and detect its inhibitory effect on the intracellular polyamine pool and colorectal cancer cell growth. METHODS: A 205-bp cDNA of AdoMetDC was reverse-inserted into recombinant pAdTrack-ODCas vectors and recombined with pAdEasy-1 vectors in AdEasy-1 cells. Positive clones were selected and transfected into the packaging cell HEK293 after they were linearized by PacI. Green fluorescent protein expression was used to monitor the process of adenovirus packaging. The ODC and AdoMetDC protein levels were identified by western blotting, and intracellular polyamine content was detected by reverse-phase high performance liquid chromatography. A viable cell count was used to determine the growth of HT-29 cells with or without exogenous polyamine. RESULTS: Sequencing confirmed that AdoMetDC cDNA was successfully ligated into the pAdTrack-ODCas vector. GFP expression in 293 cells during virus packing and amplification was observed by fluorescence microscopy. Western blotting demonstrated that both ODC and AdoMetDC were downregulated by Ad-ODC-AdoMetDCas, and consequently 3 kinds of polyamine (putrescine, spermidine and spermine) were reduced to very low levels. HT-29 cell growth was significantly inhibited as compared with control conditions, and growth arrest was not reversed by exogenous putrescine. CONCLUSION: The successfully constructed recombinant adenovirus, Ad-ODC-AdoMetDCas, blocked polyamine synthesis and has therapeutic potential for treating colorectal cancer in vitro.