Production and characterization of recombinant glucose oxidase from Aspergillus niger expressed in Pichia pastoris

Recombinant glucose oxidase from Aspergillus niger expressed in Pichia pastoris by fed-batch fermentation was purified and assessed with 1·26 purification fold to homogeneity using Q-Sepharose F.F. chromatography. The enzyme was determined by SDS-PAGE and gradient PAGE, which showed a dimeric form of 150 kDa. The purified rGOD was proved to be a glycoprotein, and the content of which was estimated to be 36·7 and 25·14% by phenol-sulfuric acid and anthrone-sulfuric acid methods. Characteristics demonstrated that the highest activity was in pH 6·0 at 40°C and was stable at a broad pH range from 4·0 to 9·0 at 55°C or below. The optimum substrate for this enzyme was d-glucose, and the Km was 21·06 mmol l(-1) as well as the Vmax was 359 μmol min(-1) mg(-1). rGOD possessed high resistance to various chemicals except for Hg(2+), Fe(2+), Ag(+), Cu(2+), 1,4-dithiothreitol, sodium dodecyl sulfate and ascorbic acid. In addition, the inhibitors also exhibited intensive fluorescence quenching effect on rGOD.

SIGNIFICANCE AND IMPACT OF THE STUDY

Glucose oxidase is a very important enzyme produced by several species. However, large-scale applications have always been postponed by its complexity in fermentation and purification. Our research focused on developing new purification strategy of recombinant GOD from A. niger expressed in P. pastoris. Here, we described this novel one-step purification method and subsequent research in the characteristics of rGOD which showed different results from previous work. These can open new opportunities to increase its application.

Long non-coding RNA MEG3 inhibits the proliferation of cervical carcinoma cells through the induction of cell cycle arrest and apoptosis

Cervical cancer remains an important public health problem worldwide. New and effective therapeutic strategies targeting cervical cancer are urgently needed. Long non-coding RNAs (lncRNAs) are newly identified regulators in tumorigenesis and tumor progression. To investigate the role of lncRNA MEG3 in the development of cervical cancer, we examined MEG3 expression in 18 pairs of cervical cancer and matched adjacent non-neoplastic tissues. Real-time quantitative RT-PCR (qRT-PCR) results showed high expression levels of MEG3 in non-neoplastic tissues, but markedly lower levels in cancer tissues. We further investigated whether the restoration of MEG3 expression might affect the proliferation of cervical carcinoma cells. Ectopic expression of MEG3 inhibited the proliferation of human cervical carcinoma cells HeLa and C-33A in vitro. On the other hand, knockdown of MEG3 promoted the growth of well-differentiated cervical carcinoma HCC94 cells. Further investigation into the mechanisms responsible for the growth inhibitory effects revealed that overexpression of MEG3 resulted in the induction of G2/M cell cycle arrest and apoptosis. These results identified an important role of MEG3 in the molecular etiology of cervical cancer and implicated the potential application of MEG3 in cervical cancer therapy.

[The relationship between histological classification of lung cancer and protein tyrosine phosphatase]

BACKGROUND

To investigate the relationship between histological classification of lung cancer and protein tyrosine phosphatase.

METHODS

The expression of protein tyrosine phosphatase in bronchial epithelia from 34 patients with benign pulmonary lesions and 121 patients with primary pulmonary carcinoma was examined by immunohistochemical staining method.

RESULTS

The positive rate of protein tyrosine phosphatase expression was 95.03%±2.10% in 34 patients with benign pulmonary lesions, 43.59%±14.41% in 121 patients with primary pulmonary carcinoma; 47.57%±16.26% in 46 patients with adenocarcinoma, 40.59%±14.04% in 48 patients with squamous cell carcinoma, 42.13%±9.84% in 27 patients with adenosquamous carcinoma; 31.63%±10.34% in 21 patients with poor differentiated squamous cell carcinoma, 41.39%±9.35% in 18 patients with intermediate differentiated squamous cell carcinoma, 59.90%±8.61% in 9 patients with well differentiated squamous cell carcinoma; 34.14%±12.53% in 16 patients with poor differentiated adenocarcinoma, 52.10%±12.19% in 26 patients with intermediate differentiated adenocarcinoma, and 63.05%±15.84% in 4 patients with well differentiated adenocarcinoma. A significant difference of protein tyrosine phosphatase positive expression was observed between benign pulmonary lesions and primary pulmonary carcinomas, and between poor differentiated primary pulmonary carcinomas and well differentiated primary pulmonary carcinomas (P<0.01 or P<0.05).

CONCLUSIONS

Detection of protein tyrosine phosphatase may be helpful to differentiate pulmonary lesions from lung cancer and be regarded as one of the indices in predicting the prognosis of patients with primary pulmonary carcinomas.

Prucalopride in the treatment of chronic constipation in patients from the Asia-Pacific region: a randomized, double-blind, placebo-controlled study

BACKGROUND

The study evaluated efficacy and safety of the 2 mg dose of prucalopride compared to placebo in patients with chronic constipation (CC) from the Asia-Pacific region.

METHODS

Randomized, placebo-controlled, parallel-group, phase III study with 2-week run-in, 12-week treatment phase, and 1-week follow-up. Adult patients with CC (≤2 spontaneous bowel movements per week) received 2 mg prucalopride or placebo, once-daily, for 12 weeks. Primary efficacy measure was percentage of patients with average of ≥3 spontaneous complete bowel movements (SCBMs) per week (Responders) during the 12-week treatment. A key secondary endpoint was Responders during first 4 weeks of treatment. Other efficacy assessments were based on patient diaries, their assessments of symptoms and quality of life, and investigator's assessment on efficacy of treatment. Safety assessments included adverse events, laboratory values, and cardiovascular events.

KEY RESULTS

Efficacy and safety were evaluated for 501 patients who received study drug. On the primary endpoint, prucalopride was significantly more effective than placebo with 83 (33.3%) vs 26 (10.3%) patients having a weekly average of ≥3 SCBMs during the 12-week treatment (P < 0.001). Respective percentages were 34.5%vs 11.1% over first 4 weeks (P < 0.001). On other secondary endpoints, clinical improvement was generally larger and statistically superior (P < 0.001) in the prucalopride group. Most frequently reported adverse events were diarrhea, nausea, abdominal pain, and headache.

CONCLUSION & INFERENCES

Prucalopride 2 mg given once-daily significantly improved bowel function, associated symptoms, and satisfaction in CC over a 12-week treatment period, and was safe and well tolerated by patients in the Asia-Pacific region.

Interactive effects of age and estrogen on cortical neurons: implications for cognitive aging

In the past few decades it has become clear that estrogen signaling plays a much larger role in modulating the cognitive centers of the brain than previously thought possible. We have developed a nonhuman primate (NHP) model to investigate the relationships between estradiol (E) and cognitive aging. Our studies of cyclical E treatment in ovariectomized (OVX) young and aged rhesus monkeys have revealed compelling cognitive and synaptic effects of E in the context of aging. Delayed response (DR), a task that is particularly dependent on integrity of dorsolateral prefrontal cortex (dlPFC) area 46 revealed the following: (1) that young OVX rhesus monkeys perform equally well whether treated with E or vehicle (V), and (2) that aged OVX animals given E perform as well as young adults with or without E, whereas OVX V-treated aged animals display significant DR impairment. We have analyzed the structure of layer III pyramidal cells in area 46 in these same monkeys. We found both age and treatment effects on these neurons that are consistent with behavioral data. Briefly, reconstructions of pyramidal neurons in area 46 from these monkeys showed that cyclical E increased the density of small, thin spines in both young and aged monkeys. However, this effect of E was against a background of age-related loss of small, thin spines, leaving aged V-treated monkeys with a particularly low density of these highly plastic spines, and vulnerable to cognitive decline. Our current interpretation is that E not only plays a critically important role in maintaining spine number, but also enables synaptic plasticity through a cyclical increase in small highly plastic spines that may be stabilized in the context of learning. Interestingly, recent studies demonstrate that chronic E is less effective at inducing spinogenesis than cyclical E. We have begun to link certain molecular attributes of excitatory synapses in area 46 to E effects and cognitive performance in these monkeys. Given the importance of synaptic estrogen receptor α (ER-α) in rat hippocampus, we focused our initial studies on synaptic ER-α in area 46. Three key findings have emerged from these studies: (1) synaptic ER-α is present in axospinous synapses in area 46; (2) it is stable across treatment and age groups (which is not the case in rat hippocampus); and (3) the abundance and distribution of synaptic ER-α is a key correlate of individual variation in cognitive performance in certain age and treatment groups. These findings have important implications for the design of hormone treatment strategies for both surgically and naturally menopausal women. This article is part of a Special Issue entitled: Neuroactive Steroids: Focus on Human Brain.

Enhanced osteoblast and osteoclast responses to a thin film sputtered hydroxyapatite coating

A sputtering technique followed by a low temperature hydrothermal treatment has been demonstrated to produce a dense-and-bioactive hydroxyapatite thin film coating. The purpose of the present study was to investigate osteoblast and osteoclast responses to the hydroxyapatite coated plates and titanium plates with similar roughness. Rat bone marrow stromal cells were cultured on these plates to induce osteoblasts. The cells showed a significantly enhanced proliferation on the hydroxyapatite surface, accompanied by increase of osteoblastic phenotypes. The co-cultured osteoclasts exhibited the significantly different cell number and morphology between the hydroxyapatite and the titanium surfaces. A series of osteoclast marker genes were more stimulated on the hydroxyapatite and thirty two percent of the hydroxyapatite surface area could be resorbed by osteoclasts. The thin film sputtered hydroxyapatite could provide a favorable surface for both osteoblast and osteoclast formation and their function, indicating its good osteoconductivity and biodegradability.

Mitochondrial nutrients stimulate performance and mitochondrial biogenesis in exhaustively exercised rats

The aim of this study was to investigate the effects of a combination of nutrients on physical performance, oxidative stress and mitochondrial biogenesis in rats subjected to exhaustive exercise. Rats were divided into sedentary control (SC), exhaustive exercise (EC) and exhaustive exercise with nutrient supplementation (EN). The nutrients include (mg/kg/day): R-α-lipoic acid 50, acetyl-L-carnitine 100, biotin 0.1, nicotinamide 15, riboflavin 6, pyridoxine 6, creatine 50, CoQ10 5, resveratrol 5 and taurine 100. Examination of running distances over the 4-week period revealed that EN rats ran significantly longer throughout the entire duration of the exhaustive exercise period compared with the EC rats. Nutrient supplementation significantly inhibited the increase in activities of alanine transaminase, lactate dehydrogenase and creatine kinase, reversed increases in malondialdehyde, inhibited decreases in glutathione S-transferase and total antioxidant capacity in plasma, and suppressed the elevation of reactive oxygen species and apoptosis in splenic lymphocytes. Nutrient supplementation increased the protein expression of mitochondrial complexes I, II and III, mtDNA number and transcription factors involved in mitochondrial biogenesis and fusion in skeletal muscle. These findings suggest that mitochondrial nutrient supplementation can reduce exhaustive exercise-induced oxidative damage and mitochondrial dysfunction, thus leading to enhancement of physical performance and of fatigue recovery.

Prognosis and role of postmastectomy radiotherapy in patients with T1-T2 breast cancer with one to three positive axillary nodes

PURPOSE

To evaluate the prognosis and role of postmastectomy radiotherapy (PMRT) in T1-T2 breast cancer with one to three positive axillary nodes.

METHODS

The 10-year Kaplan-Meier locoregional recurrence (LRR), distant recurrence (DR), disease-free survival (DFS) and overall survival (OS) were compared between the NO and 1-3N+ cohorts. The role of PMRT was evaluated in the 1-3N+ cohort.

RESULTS

The 10-year LRR, DR, DFS, OS rates in NO and the 1-3N+ cohorts were as follows: LRR 7.5% vs 19.4% (p = 0.011); DR 14.4% vs 23.0% (p = 0.029); DFS 71.3% vs 51.2% (p = 0.001) and OS 77.0% vs 58.7% (p = 0.001). Of the 192 1-3N+ patients not treated and treated with PMRT, the outcomes were: LRR 20.1% vs 18.4% (p = 0.047); DR 26.4% vs 21.5% (p = 0.743); DFS 40.2% vs 55.4% (p = 0.260) and OS 40.7% vs 66.0% (p = 0.344), respectively.

CONCLUSION

PMRT reduces the 10-year LRR rate for such patients, but further examination is needed.

Co-expression of CD147 (EMMPRIN), CD44v3-10, MDR1 and monocarboxylate transporters is associated with prostate cancer drug resistance and progression

Background:

The aim of this study is to seek an association between markers of metastatic potential, drug resistance-related protein and monocarboxylate transporters in prostate cancer (CaP).

Methods:

We evaluated the expression of invasive markers (CD147, CD44v3-10), drug-resistance protein (MDR1) and monocarboxylate transporters (MCT1 and MCT4) in CaP metastatic cell lines and CaP tissue microarrays (n=140) by immunostaining. The co-expression of CD147 and CD44v3-10 with that of MDR1, MCT1 and MCT4 in CaP cell lines was evaluated using confocal microscopy. The relationship between the expression of CD147 and CD44v3-10 and the sensitivity (IC₅₀) to docetaxel in CaP cell lines was assessed using MTT assay. The relationship between expression of CD44v3-10, MDR1 and MCT4 and various clinicopathological CaP progression parameters was examined.

Results:

CD147 and CD44v3-10 were co-expressed with MDR1, MCT1 and MCT4 in primary and metastatic CaP cells. Both CD147 and CD44v3-10 expression levels were inversely related to docetaxel sensitivity (IC₅₀) in metastatic CaP cell lines. Overexpression of CD44v3-10, MDR1 and MCT4 was found in most primary CaP tissues, and was significantly associated with CaP progression.

Conclusions:

Our results suggest that the overexpression of CD147, CD44v3-10, MDR1 and MCT4 is associated with CaP progression. Expression of both CD147 and CD44v3-10 is correlated with drug resistance during CaP metastasis and could be a useful potential therapeutic target in advanced disease.

T regulatory cells and Th1/Th2 cytokines in peripheral blood from tuberculosis patients

About 10% of people infected with Mycobacterium tuberculosis develop active tuberculosis (TB), and Th1 effector cells and Th1 cytokines play key roles in controlling M. tuberculosis infection. Here, we hypothesise that this susceptibility to M. tuberculosis infection is linked to increased T regulatory (Treg) cells and Th2 cytokines in TB patients. To test this, we recruited 101 participants (71 TB patients, 12 non-TB pulmonary diseases and 18 healthy subjects) and investigated Treg cells and Th1/Th2 cytokines in peripheral blood. CD4(+)CD25(+) T cells and CD4(+)CD25(+)FoxP3(+) T cells significantly increased and IL-5 dramatically decreased in TB patients relative to healthy subjects. CD8(+)CD28(-) T cells, IFN-gamma, TNF-alpha, IL-10 and IL-4 significantly increased in patients with culture and sputum smear-positive pulmonary TB (PTB(+)) compared with healthy subjects. CD4(+)CD25(+)FoxP3(+) and CD8(+)CD28(-) T cells significantly decreased in PTB(+) after one month of chemotherapy. CD4(+), CD4(+)CD25(+) and CD8(+)CD28(+) T cells significantly increased in extra-pulmonary TB patients after one month of chemotherapy. These findings suggest that M. tuberculosis infection induces circulating CD4(+)CD25(+)FoxP3(+) and CD8(+)CD28(-) T cell expansion, which may be related to the progression of M. tuberculosis infection, and that the balance between effector immune responses and suppression immune responses is essential to control M. tuberculosis infection.

Coexpression of invasive markers (uPA, CD44) and multiple drug-resistance proteins (MDR1, MRP2) is correlated with epithelial ovarian cancer progression

Background:

Invasion and metastases of cancer cells and the development of resistance to anticancer therapies are the main causes of treatment failure and mortality in cancer patients.

Methods:

We evaluated invasive markers of urokinase plasminogen activator (uPA) and CD44 and multiple drug-resistance (MDR) markers of MDR1 and MRP2 in four epithelial ovarian cancer (EOC) cell lines, primary tumours (n=120) and matched metastatic lesions (n=40) by immunofluoresence labelling. We correlated uPA and CD44 with MDR markers in primary and metastatic cells using confocal microscope. We also investigated the relationship of the expression of uPA, CD44 and MDR1 with various progression parameters.

Results:

The coexpression of uPA and CD44 with MDR markers was found in primary and metastatic cells. The overexpression of uPA, CD44 and MDR1 was found in most primary and matched metastatic lesions of EOC, and was significantly associated with tumour stage, grade, residual disease status, relapse and presence of ascites (P<0.05), but not with histology type (P>0.05).

Conclusions:

Our results suggest that the overexpression of uPA, CD44 and MRD1 is correlated with EOC progression; both uPA and CD44 are related with drug resistance during EOC metastasis and could be useful therapeutically.

The therapeutic effect of vasoactive intestinal peptide on experimental arthritis is associated with CD4+CD25+ T regulatory cells

Vasoactive intestinal peptide (VIP) has been found to act as a potent anti-inflammatory factor through regulating the production of both anti- and pro-inflammatory mediators and promoting Th2-type responses. In this study, we used Chicken collagen II-induced experimental arthritis (CIA) model in Wistar rats to investigate the potential effects of VIP on rheumatoid arthritis. Our results showed that in vivo treatment of CIA-induced rats with VIP had great protective benefit at both clinical and histological levels. Disease suppression was associated with the inhibition of T cells proliferation, shifting of the immune response toward a Th2-type response and expanded CD4(+)CD25(+) Treg in the periphery, which inhibited autoreactive T cell activation/expansion. In conclusion, the study provides evidence that VIP had great protective effect on CIA through its inhibition actions on pathogenic T cells.

Association of ruthenium complexes [Ru(bpy)3]2+ or [Ru(bpy)2(Mebpy-py)]2+ with Dawson polyanions α-[P2W18O62]6– or α2-[FeIII(H2O)P2W17O61]7–

The formation of electrostatically linked complexes between [Ru(bpy)3]Cl2 or [Ru(bpy)2(Mebpy-py)](PF6)2 and (TBA)6α-[P2W18O62] or (TBA)5K2α2-[FeIII(H2O)P2W17O61] in solution were studied by steady-state absorption and luminescence spectroscopy. The stoichiometry and global association constants of the formed complexes were obtained by the Job method. The formed complexes were characterized by 1H and 31P NMR spectroscopy and their electrochemical properties compared to the precursor compounds were investigated by using the cyclic voltammetry method.Key words: electrochemistry, polyoxometalate, ruthenium complex, electrostatic complex.