Multi-armed poly(aspartate-g-OEI) copolymers as versatile carriers of pDNA/siRNA

To search for potential non-viral nucleic acids carriers, a series of novel cationic polymers, multi-armed poly(aspartate-graft-oligoethylenimine) (MP-g-OEI) copolymers were designed and synthesized by grafting different types of oligoethylenimine (OEI) to a multi-armed poly(l-aspartic acid) backbone. The as-synthesized MP-g-OEI copolymers were characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance and gel permeation chromatography. These MP-g-OEI copolymers (MP423, MP600 and MP1800) exhibited good capacity in condensing nucleic acids (pDNA or siRNA) into nanosized particles (90-150nm) with positive surface charges. Gene transfection activity of the MP-g-OEI copolymers (especially MP1800) showed improved performance compared with PEI25k in both HeLa and CHO cell lines. The silencing efficiency of MP600/siRNA and MP1800/siRNA complexes showed a superior knockdown effect in CT26 and Huh-7 cell lines. Moreover, the MP-g-OEI copolymers exhibited much lower cytotoxicity than PEI25k. Flow cytometric analysis showed that MP-g-OEI copolymers could efficiently mediate the entry of nucleic acids into cells. These results suggest that MP-g-OEI copolymers may be potential non-viral gene carriers for the delivery of nucleic acids in future gene therapy.

Investigation of 20 non-HLA (human leucocyte antigen) psoriasis susceptibility loci in Chinese patients with psoriatic arthritis and psoriasis vulgaris

BACKGROUND

Recently, a number of non-HLA (human leucocyte antigen) psoriasis genetic susceptibility loci have been identified through genome-wide association studies, but data on their association with psoriatic arthritis (PsA) are lacking.

OBJECTIVES

To investigate recently identified psoriasis susceptibility loci in a cohort of Chinese patients with PsA, psoriasis vulgaris (PsV) and healthy controls.

METHODS

Twenty single-nucleotide polymorphisms (SNPs) from 20 loci were selected for genotyping in 379 patients with PsA, 595 patients with PsV and 1181 healthy controls using the MassARRAY platform (Sequenom, San Diego, CA, U.S.A.). Data handling, quality control and association were performed using PLINK software, v. 1.07. The Cochran-Armitage trend test was used to test the genotype-phenotype association.

RESULTS

PsA showed a significant association with markers at TNIP1 (rs17728338, P = 2.20 × 10(-8)), IL28RA (rs4649203, P = 5.04 × 10(-6)), IL12B (rs2082412, P = 3.82 × 10(-5)), ERAP1 (rs27524, P = 1.25 × 10(-3)), PTTG1 (rs2431697, P = 1.22 × 10(-3)) and GJB2 (rs3751385, P = 1.48 × 10(-3)) when compared with the control group. In PsV a significant association was found for IL28RA (rs4649203, P = 9.53 × 10(-7)), TNIP1 (rs17728338, P = 1.21 × 10(-4)) and ERAP1 (rs27524, P = 1.17 × 10(-3)). The allele frequencies were not statistically different between PsA and PsV except for SNPs at IL12B and ZNF816A with a nominal P-value of 0.04 and 0·01, respectively.

CONCLUSIONS

This study provides evidence for the involvement of ERAP1, IL28RA, GJB2 and PTTG1 loci in PsA susceptibility and confirmed the previously reported association with PsA and PsV. These results support the hypothesis that genetic aetiology of psoriasis is the same in both PsA and PsV and also support the higher genetic component of PsA than PsV.

Prevalence of cardiovascular disease and risk factors in the Chinese population with impaired glucose regulation: the 2007-2008 China national diabetes and metabolic disorders study

Cardiovascular disease (CVD) is one of the most common chronic diseases in China. This aim of this study is to determine the prevalence of CVDs and risk factors in Chinese impaired glucose regulation subjects.We used a multistage, stratified sampling method to select subjects from the general Chinese population aged 20 years and older. Subjects underwent an oral glucose tolerance test to identify normal glucose tolerance (NGT) and impaired glucose regulation including isolated impaired fasting glucose (i-IFG), impaired glucose tolerance (i-IGT), and combined IFG/IGT and diabetic mellitus (DM). A logistic regression analysis was performed to examine the association between glucose abnormalities and CVD events.We identified that 34 293 subjects had NGT, 1 469 i-IFG, 4 571 i-IGT, 957 IFG/IGT and 4 949 DM. The age-sex standardized prevalence rate of cardiovascular disease was 1.06% (95% CI 0.87-1.28), 1.79% (95% CI 1.37-2.33) and 3.83% (95% CI 2.79-5.24) in NGT, impaired glucose regulation and DM, respectively. Among impaired glucose subjects, prevalence of defined CVD risk factors (smoking, overweight, obesity, hypertension and dyslipidemia) was 29.52% (95% CI: 27.8-31.21), 36.25% (95% CI: 34.29-38.26), 10.05% (95% CI: 8.86-11.37), 36.43% (95% CI: 34.53-38.36) and 69.96% (95% CI: 67.87-71.98), respectively. Compared to 1 risk factor, the odds ratios (ORs) of CVDs with 2, 3 or 4 risk factors were 1.94 (95% CI: 0.74-5.09), 2.76 (95% CI: 1.06-7.21) and 5.84 (95% CI: 1.68-20.26), respectively. Additionally, compared to i-IFGs, ORs of CVDs with i-IGT and IFG/IGT were 2.88 (95%CI 1.36-6.01) and 2.12 (95% CI 0.83-5.44), respectively.The prevalence of cardiovascular risk factors was high in the Chinese impaired glucose regulation population. The postprandial hyperglycemia is more associated with CVD than isolated fasting hyperglycemia.

Optimization of auto-induction medium for G-CSF production by Escherichia coli using artificial neural networks coupled with genetic algorithm

Granulocyte colony-stimulating factor (G-CSF) is a cytokine widely used in cancer patients receiving high doses of chemotherapeutic drugs to prevent the chemotherapy-induced suppression of white blood cells. The production of recombinant G-CSF should be increased to meet the increasing market demand. This study aims to model and optimize the carbon source of auto-induction medium to enhance G-CSF production using artificial neural networks coupled with genetic algorithm. In this approach, artificial neural networks served as bioprocess modeling tools, and genetic algorithm (GA) was applied to optimize the established artificial neural network models. Two artificial neural network models were constructed: the back-propagation (BP) network and the radial basis function (RBF) network. The root mean square error, coefficient of determination, and standard error of prediction of the BP model were 0.0375, 0.959, and 8.49 %, respectively, whereas those of the RBF model were 0.0257, 0.980, and 5.82 %, respectively. These values indicated that the RBF model possessed higher fitness and prediction accuracy than the BP model. Under the optimized auto-induction medium, the predicted maximum G-CSF yield by the BP-GA approach was 71.66 %, whereas that by the RBF-GA approach was 75.17 %. These predicted values are in agreement with the experimental results, with 72.4 and 76.014 % for the BP-GA and RBF-GA models, respectively. These results suggest that RBF-GA is superior to BP-GA. The developed approach in this study may be helpful in modeling and optimizing other multivariable, non-linear, and time-variant bioprocesses.

The association of plasma free amino acids with liver enzymes in Type 2 diabetic patients

BACKGROUND

Elevated γ-glutamyl transpeptidase (GGT) and alanine aminotransferase (ALT) could predict the risk of Type 2 diabetes (T2D), but the reason for their elevation was unclear. GGT and ALT mediated the metabolism of many amino acids (AA). Up to now, it was not investigated whether abnormal AA concentration was associated with elevated liver enzymes.

AIM

This study was to investigate the status of AA in T2D and their relationship with liver enzymes.

SUBJECTS AND METHODS

A total of 132 T2D patients and 137 healthy controls were recruited. Plasma free AA were measured by high-performance liquid chromatography. The contribution of individual AA to liver enzymes was assessed by stepwise linear regression.

RESULTS

a) The levels of alanine, valine, leucine, isoleucine, phenylalanine, tyrosine, methionine, glutamate, and lysine were higher while the level of glycine was lower in T2D than in controls (all p<0.01). b) Glutamate contributed to GGT in T2D, and its contribution was even greater than that of waist circumference. Leucine, lysine, and glutamate contributed to ALT.

CONCLUSION

There were significant differences in plasma AA profile between T2D and controls. Abnormal AA might contribute to elevated liver enzymes. The interaction between AA, liver enzymes, and the risk of T2D should be further investigated by prospective studies.

The Adipose Tissue Endocrine Mechanism of the Prophylactic Protective Effect of Pioglitazone in High-Fat Diet-Induced Insulin Resistance

OBJECTIVE: To explore the adipose tissue endocrine mechanism of pioglitazone and its possible prophylactic role in insulin resistance. METHODS: Male Wistar rats were randomized to receive a normal diet (N group), a high-fat insulin resistance-inducing diet (IR group), or a high-fat diet plus treatment with pioglitazone (P group). Glucose tolerance and insulin resistance were tested at weeks 10 and 11 after starting the diet and, at week 12, adipose, liver and skeletal muscle tissue samples were taken. HepG2 cells were cultured with palmitic acid (PA), pioglitazone and PA plus pioglitazone, and RNA interference was used to downregulate adiponectin receptor (AdipoR) 2 in these cells. The mRNA and protein levels of adipokines (resistin and adiponectin), AdipoR1 and 2 and uptake of [3H]-labelled glucose were measured in the HepG2 cells. RESULTS: Resistin and adiponectin in adipose tissue and AdipoR2 in liver tissue were significantly decreased in the IR group compared with the N group. Adiponectin and AdipoR2 were significantly increased and insulin resistance significantly decreased in the P group versus the IR group. In HepG2 cells, AdipoR2 levels and glucose uptake decreased significantly when PA was ≥ 200 μM, but were elevated by pioglitazone. Small interfering RNA-AdipoR2 confirmed glucose uptake in liver was regulated by AdipoR2. CONCLUSIONS: Pioglitazone prevented insulin resistance in rats fed a high-fat diet. Liver AdipoR2-mediated glucose uptake is important in the prophylactic effect of pioglitazone on insulin resistance.

Psychological status of Chinese patients with Type 2 diabetes: data review of Diabcare-China studies

AIM

To describe the status of glycaemic control, self-reported adherence to treatments, psychological well-being and quality of life in Chinese patients with Type 2 diabetes in 2006.

METHODS

Subjects having registered for care for > 12 months at a diabetes clinic were enrolled in this study. Glycaemic control was determined by HbA(1c) and plasma glucose levels; information about self-reported adherence to treatments was obtained by questionnaire; psychological well-being was assessed by use of a modified World Health Organization-5 Well-being Index; and quality of life was measured by use of a modified Diabetes Attitudes, Wishes and Needs (DAWN) survey. All data were tabulated and statistical analyses were performed.

RESULTS

A total of 2702 patients were enrolled during 2006. Only 23% of patients achieved an HbA(1c) level of < 48 mmol/mol (6.5%) as per the 2007 China guideline for Type 2 diabetes and only 16.2% followed all treatment recommendations from healthcare providers. Of the patients, 46.0-68.6% of the patients showed positive psychological well-being. A quality-of-life survey showed that 28.5-50.6% of the patients experienced various diabetes-related emotional problems. Large percentages (approximately 50%) of patients were experiencing psychological insulin resistance.

CONCLUSIONS

Although in China therapies for Type 2 diabetes are more effective and available than ever before, the patient outcomes remain disappointing. Problems with glycaemic control, self-reported adherence to treatments, psychological well-being and quality of life, all of which are key to diabetes control, are common among Chinese patients with Type 2 diabetes.

β-Galactosidase with transgalactosylation activity from Lactobacillus fermentum K4

The LacLM β-galactosidase of Lactobacillus fermentum K4 is encoded by 2 consecutive genes, lacL (large subunit) and lacM (small subunit), that share 17 overlapping nucleotides. Phylogenetic analysis revealed that this enzyme was closely related to other Lactobacillus β-galactosidases and provided significant insight into its common and distinct characteristics. We cloned both the lacL and lacM genes of L. fermentum K4 and heterologously expressed each in Escherichia coli, although the recombinant enzyme was only functional when both were expressed on the same plasmid. We evaluated the enzymatic properties of this species-specific LacLM β-galactosidase and discovered that it acts as both a hydrolase, bioconverting lactose into glucose and galactose, and a transgalactosylase, generating prebiotic galacto-oligosaccharides (GOS). The recombinant β-galactosidase showed a broad pH optimum and stability around neutral pH. The optimal temperature and Michaelis constant (K(m)) for the substrates o-nitrophenyl-β-D-galactopyranoside and lactose were, respectively, 40°C and 45 to 50°C and 1.31 mM and 27 mM. The enzyme activity was stimulated by some cations such as Na⁺, K⁺, and Mg²⁺. In addition, activity was also enhanced by ethanol (15%, wt/vol). The transgalactosylation activity of L. fermentum K4 β-galactosidase effectively and rapidly generated GOS, up to 37% of the total sugars from the reaction. Collectively, our results suggested that the β-galactosidase from L. fermentum K4 could be exploited for the formation of GOS.

Phase I clinical study to select a novel oral formulation for ibandronate containing the excipient sodium N-[8-(2-hydroxybenzoyl) amino] caprylate (SNAC)

The aim of this study was to select a novel oral formulation for ibandronate (IBN, CAS number: 13892619). In four cohorts of 28, 21, 19 and 29 healthy volunteers, the impact of the carrier molecule sodium N-[8-(2-hydroxybenzoyl) amino] caprylate (SNAC, CAS number: 203787-91-1) on the bioavailability of IBN was investigated. Within each cohort different oral formulations with one dose of ibandronate (30 mg) and three different ratios of IBN:SNAC (1:5, 1:10 and 1:20) were compared to the approved oral IBN tablet formulations (150 and 50 mg IBN) in a 4-way cross-over design and a one week washout between the administrations. The highest mean IBN exposure was achieved with a capsule formulation containing drug-coated beadlets and an IBN:SNAC ratio of 1:5. AUC(last) and C(max) of IBN were approximately 1.3- and 2.2-fold higher compared to the reference treatment (150 mg IBN without SNAC). Increasing the post-dose fasting duration from 15 to 30 min resulted in a more than 2-fold increase in AUC(last), while superimposable IBN serum concentration-time profiles were achieved after a 30 and 60 min fast. The tolerability of the IBN/SNAC treatments in all cohorts was similar to that in the IBN reference groups and most adverse events (AEs) were of mild to moderate intensity.

Synthesis and Interfacial Properties of Novel Imidazoline Gemini Surfactants

Two novel imidazoline gemini surfactants quaternary ammonium salts of di(2-undecyl (heptadecyl)-1-formyl aminoethyl imidazoline) hexanediamine (SUAEIHDI/SHAEIHDI) were synthesized in this article, and their interfacial properties were studied. It was found that SUAEIHDI had a higher CMC value than SHAEIHDI in distillated water at constant temperature (12 ± 2) °C, indicating that it was easier for SHAEIHDI to form micelles in water. The symmetrical molecular structure of SUAEIHDI/SHAEIHDI is composed of lipophilic group and hydrophilic group comprising many active elements i. e. O, N and two imidazoline rings. The novel imidazoline gemini surfactants can be viewed as block-like copolymers, whose surface-modifying effects on nanomaterials are promising.

Enhanced chemosensitivity to CPT-11 in colorectal carcinoma xenografts by small hairpin RNA interference targeting PLK1

Commonly used drugs for the treatment of colon{} cancer patients like CPT-11 shows severe side effects or induces resistance in clinical settings. Thus, we analyzed a combination of PLK1 (polo-like kinase 1)-specific short hair RNA (shRNA), a potent tool to destroy mitosis in cancer cells, together with CPT-11 to enhance drug sensitivity. Cellular proliferation and apoptosis were determined in SW620 colorectal carcinoma cells. Knockdown of cellular PLK1 led to the decreased mRNA and PLK1 protein in RT-PCR and western blot assay. The viability declined (p<0.001) in MTT assay and colony formation assay, and the number of apoptotic cells was clearly increased (p<0.01) in flow cytometric analysis and Hoechst 33258 staining compared with control cells after incubation with PLK1-specific shRNA and SN-38. We found the level of cleaved PARP was also increased in vitro. In vivo, employment of shRNA targeting PLK1 improved the sensitivity to treat SW620 nude mouse model toward CPT-11. The combination therapy inhibited cellular proliferation and promoted apoptosis observed at the percentage of PCNA and caspase3 by immunohistochemistry, accompanied with TUNEL assay. As we expect, the combination treatment delayed tumor growth (p<0.01) and simultaneously reduced tumor weight (p<0.01) compared with control group. Taken together, combination of PLK1-specific shRNA interference with low-dose CPT-11 triggered a antitumor efficacy and represented a potential strategy to treat colon cancer.

Increasing prevalence of gestational diabetes mellitus in Chinese women from 1999 to 2008

AIMS

To investigate the trend in the prevalence of gestational diabetes mellitus during 1999-2008 in women living in urban Tianjin, China.

METHODS

A universal screening for gestational diabetes mellitus has become an integral part of the antenatal care in Tianjin, China from 1998. A total of 105,473 pregnant women living in the six urban districts of Tianjin, China, participated in the gestational diabetes mellitus screening programme between December 1998 and December 2008. The screening test consisted of a 50-g 1-h glucose test. Women who had a glucose reading ≥7.8 mmol/l at the initial screening were invited to undergo the standard 2-h oral glucose tolerance test with a 75-g glucose load. Gestational diabetes mellitus was confirmed using the World Health Organization's diagnostic criteria.

RESULTS

The adjusted prevalence of gestational diabetes mellitus increased by 2.8 times during 1999-2008, from 2.4 to 6.8% (P<0.0001 for linear trend). In 2008, the age-specific prevalence of gestational diabetes mellitus was the highest among women aged 30-34 years (11.3%) and lowest among women aged 25 and under (1.2%). In women aged 35 years and more, the prevalence was 5.3%.

CONCLUSIONS

The prevalence of gestational diabetes mellitus has markedly been increasing in a universally screened urban Chinese female population and has become an important public health problem in China.

A role for nucleotides in support of breast cancer angiogenesis: heterologous receptor signalling

Background:

Human breast carcinoma cells secrete an adenosine 5′-diphosphate transphosphorylase (sNDPK) known to induce endothelial cell tubulogenesis in a P2Y receptor-dependent manner. We examined sNDPK secretion and its effects on human endothelial cells.

Methods:

Nucleoside diphosphate kinase (NDPK) secretion was measured by western blot and enzyme-linked immunosorbent assay, while transphosphorylase activity was measured using the luciferin-luciferase ATP assay. Activation of MAPK was determined by western blot analysis, immunofluorescence and endothelial cell proliferation and migration.

Results:

A panel of breast cancer cell lines with origin as ductal carcinoma, adenocarcinoma or medullary carcinoma, secrete sNDPK-A/B. Addition of purified NDPK-B to endothelial cultures activated VEGFR-2 and Erk_1/2, both of which were blocked by inhibitors of NDPK and P2Y receptors. Activation of VEGFR-2 and ErK_1/2 by 2-methylthio-ATP (2MeS-ATP) was blocked by pretreatment with the P2Y₁-specific antagonist MRS2179, the proto-oncogene non-receptor tyrosine kinase (Src) inhibitor PP2 or the VEGFR-2 antagonist SU1498. Nucleoside diphosphate kinase-B stimulates cell growth and migration in a concentration-dependent manner comparable to the effect of vascular endothelial growth factor. Treatment of endothelial cells with either NDPK-B or 2MeS-ATP induced migration, blocked by P2Y₁, Src or VEGFR-2 antagonists.

Conclusion:

sNDPK supports angiogenesis. Understanding the mechanism of action of sNDPK and P2Y₁ nucleotide signalling in metastasis and angiogenesis represent new therapeutic targets for anti-angiogenic therapies to benefit patients.