Elucidation of the Mechanism of Elicitation in Penicillium Chrysogenum: Systematic Approach to Study the Effect of Oligosaccharides on Production of Penicillin G

The addition of an oligosaccharide elicitor results in a series of coordinated events leading to stimulation of various morphological and/or physiological responses in Penicillium chrysogenum. Whilst elicitation in P. chrysogenum has been reported and is now established, no scientific evidence has been put forward to explain the complex phenomenon behind the observations. To expand the potential of elicitation in fungi from laboratory to industrial scale it is essential to establish the potential generic nature of the elicitor’s effect and to provide concrete reasons for the changes observed. This work, serves as a starting point for the elucidation of some possible mechanisms. Mannan oligosaccharides (MO) derived from locust bean gum, and oligomannuronate (OM) from alginate were used in these studies. The effect of multiple addition of the same elicitor was investigated with a prospect that repeated addition would re-trigger the stimulation resulting in either maintenance of the penicillin G levels or enhancement of the production rate. However repeated addition of the same elicitor did not show any change in the production rate in comparison to single additions. Multiple additions of different elicitor types at different times and concentrations in a 5 L bioreactor showed an increase of 150% and 100% in the penicillin G production rate compared to the control and single elicitor addition cultures. The importance of structure-activity relationship of oligosaccharides in elicitation was investigated. In this study the reducing end of MO was reduced and the modified MO (MO-R) was used to study the structure-activity relationship. Addition of MO-R resulted in a 65% decrease in the elicitor activity, but did not eliminate the ability of the oligosaccharide to enhance the production of penicillin G when compared to the untreated oligosaccharides. The effect of single and multiple elicitor addition was also studied at the transcriptional level and showed that the transcript copy number in the elicited cultures was significantly higher (p <0.001) for the three major penicillin G biosynthetic genes (pcbAB, pcbC and penDE) in comparison to the control cultures. The effect of elicitor addition on the cytosolic calcium level was investigated. A fluorescent method was developed that provides a dynamic and reliable technique for the analysis of cytosolic calcium changes. The addition of elicitors showed a significant increase in the cytosolic Ca2+ compared to control cultures to which no elicitor was added (p < 0.001). The results found in this work aim to bring forward an understanding of the mechanism of action of elicitors in fungal cells

Clarithromycin: overview and its current clinical utility in the treatment of respiratory tract infections

Upper respiratory tract infection (URTI) is a common reason for medical consultation all over the world. Streptococcus A (Strep A) and other infections can cause sore throat as well as pharyngitis or tonsillitis. It may also result in post-infection sequelae, including acute post-streptococcal glomerulonephritis, acute rheumatic fever, and rheumatic heart disease.  As a result, there is a need for an antibiotic that is effective, easy to administer, has a favorable sensitivity pattern, and preferably has some additional pharmacodynamic properties that complement the basic antibacterial profile. Clarithromycin is a macrolide antibacterial agent with broad-spectrum activity against respiratory pathogens. It is especially active against atypical Chlamydia pneumoniae, Mycoplasma pneumoniae, and Legionella spp. It is well absorbed and stable at gastric pH. It is metabolized by the cytochrome P450 enzymes and forms 14-hydroxy clarithromycin, which is more active than the parent compound, especially against Hemophilus influenzae. It acts by preventing protein synthesis by binding to the 50S subunit of bacterial ribosomes. In dosages of 500 to 1000 mg/day for 5 to 14 days, clarithromycin is effective in the treatment of community-acquired upper and lower respiratory tract infections in hospital and community settings. It exerts significant anti-inflammatory, immunomodulatory, and post-antibiotic effects. It provides a viable option for the treatment of community-acquired respiratory tract infections, in both children and adults.  

Genomic insights into triple-negative and HER2-positive breast cancers using isogenic model systems

Introduction In general, genomic signatures of breast cancer subtypes have little or no overlap owing to the heterogeneous genetic backgrounds of study samples. Thus, obtaining a reliable signature in the context of isogenic nature of the cells has been challenging and the precise contribution of isogenic triple negative breast cancer (TNBC) versus non-TNBC remains poorly defined. Methods We established isogenic stable cell lines representing TNBC and Human Epidermal Growth Factor Receptor 2 positive (HER2+) breast cancers by introducing HER2 in TNBC cell lines MDA-MB-231 and MDA-MB-468. We examined protein level expression and functionality of the transfected receptor by treatment with an antagonist of HER2. Using microarray profiling, we obtained a comprehensive gene list of differentially expressed between TNBC and HER2+ clones. We identified and validated underlying isogenic components using qPCR and also compared results with expression data from patients with similar breast cancer subtypes. Results We identified 544 and 1087 statistically significant differentially expressed genes between isogenic TNBC and HER2+ samples in MDA-MB-231 and MDA-MB-468 backgrounds respectively and a shared signature of 49 genes. By comparing results from MDA-MB-231 and MDA-MB-468 backgrounds with two patient microarray datasets, we identified 17 and 22 common genes with same expression trend respectively. Additionally, we identified 56 and 78 genes from MDA-MB-231 and MDA-MB-468 comparisons respectively present in our published RNA-seq data. Conclusions Using our unique model system, we have identified an isogenic gene expression signature between TNBC and HER2+ breast cancer. A portion of our results was also verified in patient data samples, indicating an existence of isogenic element associated with HER2 status between genetically heterogeneous breast cancer samples. These findings may potentially contribute to the development of molecular platform that would be valuable for diagnostic and therapeutic decision for TNBC and in distinguishing it from HER2+ subtype

Magneto-Electric Nano-Particles for Non-Invasive Brain Stimulation

This paper for the first time discusses a computational study of using magneto-electric (ME) nanoparticles to artificially stimulate the neural activity deep in the brain. The new technology provides a unique way to couple electric signals in the neural network to the magnetic dipoles in the nanoparticles with the purpose to enable a non-invasive approach. Simulations of the effect of ME nanoparticles for non-invasively stimulating the brain of a patient with Parkinson’s Disease to bring the pulsed sequences of the electric field to the levels comparable to those of healthy people show that the optimized values for the concentration of the 20-nm nanoparticles (with the magneto-electric (ME) coefficient of 100 V cm21 Oe21 in the aqueous solution) is 36106 particles/cc, and the frequency of the externally applied 300-Oe magnetic field is 80 Hz

Magneto-electric Nanoparticles to Enable Field-controlled High-Specificity Drug Delivery to Eradicate Ovarian Cancer Cells

The nanotechnology capable of high-specificity targeted delivery of anti-neoplastic drugs would be a significant breakthrough in Cancer in general and Ovarian Cancer in particular. We addressed this challenge through a new physical concept that exploited (i) the difference in the membrane electric properties between the tumor and healthy cells and (ii) the capability of magneto-electric nanoparticles (MENs) to serve as nanosized converters of remote magnetic field energy into the MENs’ intrinsic electric field energy. This capability allows to remotely control the membrane electric fields and consequently trigger high-specificity drug uptake through creation of localized nano-electroporation sites. In in-vitro studies on human ovarian carcinoma cell (SKOV-3) and healthy cell (HOMEC) lines, we applied a 30-Oe d.c. field to trigger high-specificity uptake of paclitaxel loaded on 30-nm CoFe2O4@BaTiO3 MENs. The drug penetrated through the membrane and completely eradicated the tumor within 24 hours without affecting the normal cells

Externally controlled on-demand release of anti-HIV drug using magneto-electric nanoparticles as carriers

Although highly active anti-retroviral therapy has resulted in remarkable decline in the morbidity and mortality in AIDS patients, inadequately low delivery of anti-retroviral drugs across the blood–brain barrier results in virus persistence. The capability of high-efficacy-targeted drug delivery and on-demand release remains a formidable task. Here we report an in vitro study to demonstrate the on-demand release of azidothymidine 5′-triphosphate, an anti-human immunodeficiency virus drug, from 30 nm CoFe2O4@BaTiO3 magneto-electric nanoparticles by applying a low alternating current magnetic field. Magneto-electric nanoparticles as field-controlled drug carriers offer a unique capability of field-triggered release after crossing the blood–brain barrier. Owing to the intrinsic magnetoelectricity, these nanoparticles can couple external magnetic fields with the electric forces in drug–carrier bonds to enable remotely controlled delivery without exploiting heat. Functional and structural integrity of the drug after the release was confirmed in in vitro experiments with human immunodeficiency virus-infected cells and through atomic force microscopy, spectrophotometry, Fourier transform infrared and mass spectrometry studies

Functional and biological properties of the nuclear receptor coregulator PELP1/MNAR

Proline-, glutamic acid-, and leucine-rich protein (PELP)1, also known as modulator of nongenomic actions of the estrogen receptor (MNAR), is a novel nuclear receptor coregulator with a multitude of functions. PELP1/MNAR serves as a scaffolding protein that couples various signaling complexes with nuclear receptors and participates in genomic and nongenomic functions. Recent data suggest that PELP1/MNAR expression is deregulated in several cancers, including breast, endometrial, prostate, and ovarian cancer, and that PELP1/MNAR interacts with several oncogenes. In this review, we summarize the emerging biological properties and functions of PELP1/MNAR

RNA sequencing of cancer reveals novel splicing alterations

Breast cancer transcriptome acquires a myriad of regulation changes, and splicing is critical for the cell to “tailor-make” specific functional transcripts. We systematically revealed splicing signatures of the three most common types of breast tumors using RNA sequencing: TNBC, non-TNBC and HER2-positive breast cancer. We discovered subtype specific differentially spliced genes and splice isoforms not previously recognized in human transcriptome. Further, we showed that exon skip and intron retention are predominant splice events in breast cancer. In addition, we found that differential expression of primary transcripts and promoter switching are significantly deregulated in breast cancer compared to normal breast. We validated the presence of novel hybrid isoforms of critical molecules like CDK4, LARP1, ADD3, and PHLPP2. Our study provides the first comprehensive portrait of transcriptional and splicing signatures specific to breast cancer sub-types, as well as previously unknown transcripts that prompt the need for complete annotation of tissue and disease specific transcriptome

Novel insights into breast cancer genetic variance through RNA sequencing

Using RNA sequencing of triple-negative breast cancer (TNBC), non-TBNC and HER2-positive breast cancer sub-types, here we report novel expressed variants, allelic prevalence and abundance, and coexpression with other variation, and splicing signatures. To reveal the most prevalent variant alleles, we overlaid our findings with cancer- and population-based datasets and validated a subset of novel variants of cancer-related genes: ESRP2, GBP1, TPP1, MAD2L1BP, GLUD2 and SLC30A8. As a proof-of-principle, we demonstrated that a rare substitution in the splicing coordinator ESRP2(R353Q) impairs its ability to bind to its substrate FGFR2 pre-mRNA. In addition, we describe novel SNPs and INDELs in cancer relevant genes with no prior reported association of point mutations with cancer, such as MTAP and MAGED1. For the first time, this study illustrates the power of RNA-sequencing in revealing the variation landscape of breast transcriptome and exemplifies analytical strategies to search regulatory interactions among cancer relevant molecules