MicroRNA-215 enhances invasion and migration by targeting retinoblastoma tumor suppressor gene 1 in high-grade glioma

Objective

To elucidate the molecular mechanism of microRNA-215 (miR-215) in the migration and invasion of high grade glioma.

Results

42 Patients were analysed for clinicopathological characteristics. qRT-PCR showed that miR-215 was up-regulated in glioma tissues compared with non-neoplastic brain tissues (P < 0.05). The up-regulated miR-215 was closely associated with high grade glioma (P < 0.01) and poor overall survival (P < 0.01). Transwell assay showed that re-expression of miR-215 enhanced migration and invasion of glioma cells. miR-215 also down-regulated retinoblastoma tumor suppressor gene 1 (RB1) expression by targeting its 3′-UTR. Reversely, re-expression of RB1 inhibited partial effect of miR-215 on migration and invasion in vitro.

Conclusions

Re-expression of miR-215 promoted cell migration and invasion of glioma by targeting RB1. miR-215 can thus be used as a biomarker for tumor progression and prognosis in human high grade glioma.

     

Intramuscular injection of mechano growth factor E domain peptide regulated expression of memory-related <Emphasis Type="Italic">sod</Emphasis>, miR-134 and miR-125b-3p in rat hippocampus under simulated weightlessness

Objective

To investigate the expression of memory-related antioxidant genes and miRNAs under simulated weightlessness and the regulation of mechano growth factor (MGF) E domain, the peptide preventing nerve damage.

Results

Igf-iea and mgf mRNA levels, expression of antioxidant genes sod1 and sod2 and levels of miR-134 and miR-125b-3p increased in rat hippocampus after 14 days tail suspension to simulate weightlessness which was inhibited with intramuscular injection of E domain peptide. Therefore, administration of MGF E domain peptide could reverse increased expressions of memory-related igf-iea, mgf, sod1, sod2, miR-134 and miR-125b-3p in rat hippocampus under simulated weightlessness.

Conclusions

MGF may regulate the redox state and miRNA-targeted NR-CREB signaling, and intramuscular injection may be the alternative administration because of its safety, convenience and ability to pass through the blood brain barrier.

     

miR-215 functions as an oncogene in high-grade glioma by regulating retinoblastoma 1

Objectives

To investigate the roles of miR-215 in high-grade glioma and to clarify the regulation of retinoblastoma 1 (RB1) by miR-215.

Results

miR-215 is frequently up-regulated in high-grade glioma tissues. Increased miR-215 expression is significantly associated with World Health Organization grade (P < 0.01) tumor size (P < 0.05) and poor prognosis (P < 0.01). Over-expression of miR-215 promoted cell proliferation and knockdown of miR-215 inhibited cell proliferation in vitro. RB1 was identified as a direct and functional target of miR-215. RB1 is generally down-regulated in glioma tissues and its expression inversely correlated with miR-215, which is up-regulated in high-grade glioma tissues, and its expression was negatively correlated with miR-215.

Conclusions

The new miR-215/RB1 axis provides new insights into the molecular mechanism and treatment for glioma.

     

Over-expression of miR-146b and its regulatory role in intestinal epithelial cell viability,proliferation, and apoptosis in piglets

Background

Weaning stress affects the small intestine of piglets. MiR-146b is differentially expressed in suckling and weaned piglets. In this study, we evaluated the effects of miR-146b on cell viability, proliferation, and apoptosis in IPEC-J2 cells.

Results

Transfection with miR-146b mimics successfully increased miR-146b levels by 1000× (P?<?0.001). The over-expression of miR-146b significantly promoted the apoptosis (P?<?0.01) of IPEC-J2 cells, with no significant effects on cell viability or proliferation. MiR-146b suppressed the luciferase activity of the miR-TLR4-wt by 57% compared with the negative control, while mutation of the miR-146b binding site significantly blocked the suppressive effect (P?<?0.05). Western blot results showed that TLR4 levels decreased in IPEC-J2 cells transfected with miR-146b mimics (P?<?0.05).

Conclusions

The over-expression of miR-146b promotes IPEC-J2 cell apoptosis. TLR4 is a direct target of miR-146b in IPEC-J2 cells.

Reviewers

This article was reviewed by Eugene Berezikov and Jan B Hoek.

     

Improved production of carotenoid-free welan gum in a genetic-engineered <Emphasis Type="Italic">Alcaligenes</Emphasis> sp. ATCC31555

Objective

To improve the production of welan gum and obtain a carotenoid-free strain while reducing the fermentation and post-treatment costs.

Results

The vitreoscilla globin (vgb) gene combined with the β-galactosidase (lacZ) promoter was inserted into the phytoene synthase (crtB) gene region of the chromosome in Alcaligenes sp. ATCC31555. When the recombinant strain was grown in a 5 l fermentor, welan gum was produced at 24 ± 0.4 g l^?1 compared to 21 g ± 0.4 g l^?1 in the wild type. Furthermore, the carotenoid-free welan gum produced using Alcaligenes sp. ATCC31555 VHb strain was less expensive with improved properties.

Conclusions

Alcaligenes sp. ATCC31555 VHb strain was a better neutral welan-producing strain with a higher production than the wild-type strain.

     

Expression,purification and characterization of a thermostable leucine dehydrogenase from the halophilic thermophile <Emphasis Type="Italic">Laceyella sacchari</Emphasis>

Objective

A potential thermotolerant l-leucine dehydrogenase from Laceyella sacchari (Ls-LeuDH) was over-expressed in E. coli, purified and characterized.

Results

Ls-LeuDH had excellent thermostability with a specific activity of 183 U/mg at pH 10.5 and 25 °C. It retained a high activity in 200 mM carbonate buffer from pH 9.5 to 11. The optimal temperature for Ls-LeuDH was 60 °C.

Conclusion

It is the first time that a thermostable and highly active LeuDH originating from L. sacchari has been characterized. It may be useful for medical and pharmaceutical applications.

     

Genotyping and Persistence of <Emphasis Type="Italic">Candida albicans</Emphasis> from Pregnant Women with Vulvovaginal Candidiasis

Objective

To study Candida albicans genotypes using RAPD and their susceptibility to fluconazole in healthy pregnant women and in vulvovaginal candidiasis (VVC) patients after topical treatment with clotrimazole.

Methods

Vaginal swabs were collected at t = 0 and t = 1 (1 month later) in pregnant women (control group, n = 33), and before (t = 0), at 1 month (t = 1) and at 2 months (t = 2) after clotrimazole treatment in pregnant women with VVC.

Results

Candida albicans was isolated in 30% of healthy pregnant women and 80% of patients with VVC. A high genetic heterogeneity was observed in C. albicans genotypes between individuals. In patients with VVC, topical antifungal treatment with clotrimazole was clinically effective, but only in a 62% C. albicans was eradicated. In patients in which C. albicans was not eradicated, this microorganism persisted for 1 or 2 months after the antifungal treatment. The persistent colonies were not associated with a specific genotype, but they were associated with higher MICs in comparison with colonies isolated from the control group.

Conclusions

Therapy with topical clotrimazole, despite a good clinical outcome, could not eradicate completely C. albicans allowing the persistence of genotypes, with higher MICs to fluconazole. More studies with higher number of patients are needed to validate this preliminary finding.

     

Increased riboflavin production by knockout of 6-phosphofructokinase I and blocking the Entner–Doudoroff pathway in <Emphasis Type="Italic">Escherichia coli</Emphasis>

Objectives

To construct an Escherichia coli strain capable of producing riboflavin with high titer and yield.

Results

A low copy number plasmid pLS01 containing a riboflavin operon under the control of a constitutive promoter was constructed and introduced into Escherichia coli MG1655. Subsequently, the pfkA, edd and ead genes were disrupted, and the resulting strain LS02T produced 667 mg riboflavin/l in MSY medium supplied with 10 g glucose/l in flask cultivation. In a fed-batch process, riboflavin production of the strain reached 10.4 g/l with a yield of 56.8 mg riboflavin/g glucose.

Conclusion

To our knowledge, this is the first report of engineered E. coli strains that can produce more than 10 g riboflavin/l in fed-batch cultivation, indicating that E. coli has potential for riboflavin production.

     

Does centrifugation matter? Centrifugal force and spinning time alter the plasma metabolome

Background

Centrifugation is an indispensable procedure for plasma sample preparation, but applied conditions can vary between labs.

Aim

Determine whether routinely used plasma centrifugation protocols (1500×g 10 min; 3000×g 5 min) influence non-targeted metabolomic analyses.

Methods

Nuclear magnetic resonance spectroscopy (NMR) and High Resolution Mass Spectrometry (HRMS) data were evaluated with sparse partial least squares discriminant analyses and compared with cell count measurements.

Results

Besides significant differences in platelet count, we identified substantial alterations in NMR and HRMS data related to the different centrifugation protocols.

Conclusion

Already minor differences in plasma centrifugation can significantly influence metabolomic patterns and potentially bias metabolomics studies.

     

Contribution of direct electron transfer mechanisms to overall electron transfer in microbial fuel cells utilising <Emphasis Type="Italic">Shewanella oneidensis</Emphasis> as biocatalyst

Objectives

To investigate the contribution of direct electron transfer mechanisms to electricity production in microbial fuel cells by physically retaining Shewanella oneidensis cells close to or away from the anode electrode.

Results

A maximum power output of 114 ± 6 mWm^?2 was obtained when cells were retained close to the anode using a dialysis membrane. This was 3.5 times more than when the cells were separated away from the anode. Without the membrane the maximum power output was 129 ± 6 mWm^?2. The direct mechanisms of electron transfer contributed significantly to overall electron transfer from S. oneidensis to electrodes, a result that was corroborated by another experiment where S. oneidensis cells were entrapped in alginate gels.

Conclusion

S. oneidensis transfers electrons primarily by direct electron transfer as opposed to mediated electron transfer.

     

The role of <Emphasis Type="Italic">IFITM3</Emphasis> in the growth and migration of human glioma cells

Background

Interferon induced transmembrane protein 3 (IFITM3) is transcribed in most tissues and highly interferon-inducible. However, the role of IFITM3 in cancer is still poorly understood.

Methods

Expression levels ofIFITM3were analyzed in 60 glioma patients by immunohistochemistry (IHC). Following closely, we investigated the phenotype of IFITM3 knockdown on glioma cell growth and tumorigenesis in vitro using lentivirus-mediated loss-of-function strategy.

Results

Depletion of IFITM3in U251 cells dramatically inhibited cell proliferation and colony formation, which demonstrated that reduced IFITM3 protein levels could cause inhibition of tumorigenesis. Knockdown of IFITM3 also induced cell cycle arrest in G0/G1 phase, especially in the sub-G1 phase representing apoptotic cells. In addition, the migration of U251 cells was visibly weakened after IFITM3 knockdown, as determined by Transwell assay.

Conclusions

Our findings provide new evidence that IFITM3 plays an important role in glioma cell growth and migration, suggesting that silencing of IFITM3 by RNA interference (RNAi) may be a potential approach to suppress glioma growth.

     

Expression of lycopene biosynthesis genes fused in line with Shine-Dalgarno sequences improves the stress-tolerance of <Emphasis Type="Italic">Lactococcus lactis</Emphasis>

Objectives

Lycopene biosynthetic genes from Deinococcus radiodurans were co-expressed in Lactococcus lactis to produce lycopene and improve its tolerance to stress.

Results

Lycopene-related genes from D. radiodurans, DR1395 (crtE), DR0862 (crtB), and DR0861 (crtI), were fused in line with S hine-Dalgarno (SD) sequences and co-expressed in L. lactis. The recombinant strain produced 0.36 mg lycopene g^-1 dry cell wt after 48 h fermentation. The survival rate to UV irradiation of the recombinant strain was higher than that of the non-transformed strain.

Conclusion

The L. lactis with co-expressed genes responsible for lycopene biosynthesis from D. radiodurans produced lycopene and exhibited increased resistance to UV stress, suggesting that the recombinant strain has important application potential in food industry.

     

Diabetic nephropathy: serum miR-9 confers a poor prognosis in and is associated with level changes of vascular endothelial growth factor and pigment epithelium-derived factor

Objective

To investigate the relationship between the serum level of miR-9 and the progression of diabetic nephropathy (DN) and related molecular mechanisms.

Results

Thirty-five healthy subjects and 140 DN patients were divided into five groups: control, DN I–II, DN III, DN IV and DN V. Serum level of miR-9 was measured by real-time qPCR. Serum levels of vascular endothelial growth factor (VEGF), pigment epithelium-derived factor (PEDF) lipids, fasting glucose, insulin, hemoglobin A1c (HBA1c), creatinine, fibrinogen and insulin resistance (HOMA-IR) were also measured. The results show that the levels of miR-9, PEDF and VEGF are increased with DN progression (P < 0.05). miR-9, VEGF and PEDF are independent risk factors of DN (R² = 0.430). Spearman rank correlation analysis showed that miR-9 level is positively related to the levels of VEGF, PEDF, cholesterol, triglyceride, fasting glucose, fasting insulin, HBA1c, creatinine, fibrinogen and HOMA-IR (P < 0.05).

Conclusions

Serum miR-9 is a potential marker for conferring a poor prognosis in DN and associated with the levels of VEGF, PEDF and biochemical indices.

     

Targeting myomiRs by tocotrienol-rich fraction to promote myoblast differentiation

Background

Several muscle-specific microRNAs (myomiRs) are differentially expressed during cellular senescence. However, the role of dietary compounds on myomiRs remains elusive. This study aimed to elucidate the modulatory role of tocotrienol-rich fraction (TRF) on myomiRs and myogenic genes during differentiation of human myoblasts. Young and senescent human skeletal muscle myoblasts (HSMM) were treated with 50 μg/mL TRF for 24 h before and after inducing differentiation.

Results

The fusion index and myotube surface area were higher (p?<?0.05) on days 3 and 5 than that on day 1 of differentiation. Ageing reduced the differentiation rate, as observed by a decrease in both fusion index and myotube surface area in senescent cells (p?<?0.05). Treatment with TRF significantly increased differentiation at days 1, 3 and 5 of young and senescent myoblasts. In senescent myoblasts, TRF increased the expression of miR-206 and miR-486 and decreased PTEN and PAX7 expression. However, the expression of IGF1R was upregulated during early differentiation and decreased at late differentiation when treated with TRF. In young myoblasts, TRF promoted differentiation by modulating the expression of miR-206, which resulted in the reduction of PAX7 expression and upregulation of IGF1R.

Conclusion

TRF can potentially promote myoblast differentiation by modulating the expression of myomiRs, which regulate the expression of myogenic genes.

     

Rapid evolution of hyaluronan synthase to improve hyaluronan production and molecular mass in <Emphasis Type="Italic">Bacillus subtilis</Emphasis>

Objectives

To improve the production and molecular mass of the glycosaminoglycan hyaluronan (HA) in Bacillus subtilis by engineering hyaluronan synthase (HAS) from Streptococcus zooepidemicus.

Results

By mutating regions within HAS intracellular domains, five positive variants exhibiting higher HA production (from 1.22 to 2.24 g l^?1) and molecular mass values (from 1.20 to 1.36 × 10⁶ Da) were constructed and characterized. Overexpression of the V5 variant and the genes tuaD and glmU increased HA production and molecular mass to 2.8 g l^?1 and 2.4 × 10⁶ Da, respectively.

Conclusions

This study provides a novel strategy for improving HA production and its molecular mass.

     

Low temperature and <Emphasis Type="Italic">Daphnia</Emphasis>-associated infochemicals promote colony formation of <Emphasis Type="Italic">Scenedesmus obliquus</Emphasis> and its harvesting

Objective

To explore the combined effects of temperature and Daphnia-associated infochemicals on colony formation of Scenedesmus obliquus to faciliate harvesting the algal biomass.

Results

A three-parameter modified Gaussian model fitted the changes of the number of cells per particle in S. obliquus induced by Daphnia culture filtrate well under any temperature. Decreases in temperature enhanced the induced–colony formation of Scenedesmus. The maximum colony size at 15–25 °C was significantly larger than those at 30–35 °C. An additional 1 or 2 days at low temperature was needed to reach the maximum colony size, which indicates the best harvest time for algal biomass.

Conclusion

Induced-colony formation of Scenedesmus by Daphnia culture filtrate at 15–25 °C is recommended to settle algal cells. This condition facilitates harvesting the biomass.

     

Inactivation of virginiamycin by <Emphasis Type="Italic">Aureobasidium pullulans</Emphasis>

Objective

To test the inactivation of the antibiotic, virginiamycin, by laccase-induced culture supernatants of Aureobasidium pullulans.

Results

Fourteen strains of A. pullulans from phylogenetic clade 7 were tested for laccase production. Three laccase-producing strains from this group and three previously identified strains from clade 5 were compared for inactivation of virginiamycin. Laccase-induced culture supernatants from clade 7 strains were more effective at inactivation of virginiamycin, particularly at 50 °C. Clade 7 strain NRRL Y-2567 inactivated 6 µg virginiamycin/ml within 24 h. HPLC analyses indicated that virginiamycin was degraded by A. pullulans.

Conclusions

A. pullulans has the potential for the bioremediation of virginiamycin-contaminated materials, such as distiller’s dry grains with solubles (DDGS) animal feed produced from corn-based fuel ethanol production.

     

Enhanced succinic acid production in <Emphasis Type="Italic">Corynebacterium glutamicum</Emphasis> with increasing the available NADH supply and glucose consumption rate by decreasing H<Superscript>+</Superscript>-ATPase activity

Objectives

To enhance succinic acid production in Corynebacterium glutamicum by increasing the supply of NADH and the rate of glucose consumption by decreasing H⁺-ATPase activity.

Results

A mutant of C. glutamicum NC-3-1 with decreased H⁺-ATPase activity was constructed. This increased the rate of glycolysis and the supply of NADH. Fermentation of C. glutamicum NC-3-1 gave 39 % higher succinic acid production (113 and 81 g/l), a 29 % higher succinic acid yield (0.94 and 0.73 g succinic acid/g glucose) and decreased by-products formation compared to that of C. glutamicum NC-3 in 5 l bioreactor.

Conclusion

The point mutation in C. glutamicum NC-3-1 increased the rate of glycolysis and resulted in higher succinic acid production, higher succinic acid yield and significantly decreased formation of by-products.