Open Access Original Research Article

Identification of microRNAs Involved in mTOR Nutrient Signaling during Adipocyte Differentiation

Theresa Kaeuferle, Andrea Osswald, Katrin K. Fleischmann, Philipp Pagel, Julia V. Frowein, Susanne Krauss- Etschmann, Adelbert A. Roscher

Journal of Advances in Biology & Biotechnology, Page 109-122
DOI: 10.9734/JABB/2015/14250

Aims: In this study, we specifically aimed at identifying distinct miRNAs that are governing nutrient-driven adipogenesis via the mTOR pathway.

Methodology: The murine pre-adipocyte cell line 3T3-L1 was differentiated in the presence and absence of mTOR inhibitor rapamycin. MiRNA profiles were generated using two different array platforms. Differential regulated miRNAs were subjected to in silico target prediction. Candidate miRNA-target pairs were studied via luciferase assays, transfection assays and functional assays.

Results: This study confirmed 31 previously known and revealed 7 additional miRNAs, namely miR-34a, -96, -106b, -148b, -214*, ‑678 and -690 as being involved in adipocyte differentiation. Furthermore, we identified a subset of 16 miRNAs showing both responsiveness to rapamycin and being predicted to target genes within the mTOR pathway. Within mTOR signaling, the novel miRNA-target pairs miR183-Tsc1 (tuberous sclerosis 1), miR378-Tsc1 and miR103-Pik3r1 (phosphatidylinositol 3-kinase regulatory subunit alpha), were confirmed via luciferase-based binding assays. Accordingly we observed down-regulation of Tsc1 on transcript level in cells transfected with miR-183 or -378 (18.3 % P = .004 and 40.4 % P < .0001). However, on protein level we could detect Tsc1 up-regulation (35.7 % and 39.8 %), which is consistent with an inhibitory influence on mTOR signaling (33.6 % and 32.9 %) and on adipocyte differentiation of these miRNAs.

Conclusion: Our findings reveal a novel role for a set of miRNAs during adipocyte differentiation and mTOR signaling. Especially the attenuating effect of miR-183 and -378 on adipocyte differentiation and mTOR signaling suggests their potential as biomarkers for nutrient-driven dysregulation of adipogenesis.

Open Access Original Research Article

Biodegradation and Detoxification of Bisphenol-A by Filamentous Fungi Screened from Nature

A. Fouda, A. M. A. Khalil, H. H. El-Sheikh, E. M. Abdel-Rhaman, A. H. Hashem

Journal of Advances in Biology & Biotechnology, Page 123-132
DOI: 10.9734/JABB/2015/13959

Aims: This study demonstrated obtaining fungal isolates able to degrade and reduce the toxicity of Bisphenol-A (BPA).

Study Design: Soils enclosed by; gas stations, paint industries, and pesticides wastes, Cairo, Egypt, will be used for fungal isolation. BPA will be utilized as a sole carbon and energy source for fungal selectivity. Selected fungal strains will be optimized for BPA degradation. The residues of BPA in cultures will be determined. BPA degradation products will be identified. The toxicity of BPA degradation products on in-vitro cell viability of mammalian cell line will be investigated.

Place and Duration of Study: The study was performed in Mycological lab in botany & microbiology department in faculty of science, Al-azhar university and the Regional Center for Mycology and Biotechnology from October 2012 until May 2014.

Methodology: Different types of media shall be used for isolation, identification and purification processes. Determination of BPA concentrations will be assayed by High performance liquid chromatography (HPLC). BPA degradation products will be identified by Gas chromatography–mass spectrometry (GC-MS). Cytotoxicity test will be measured by Mammalian cell line: Vero cells (derived from the kidney of a normal African green monkey).

Results: Six soil samples were collected from different localities contaminated with petroleum and industrial wastes then 52 fungal isolates were purified before screened for BPA degradation. Two promising fungal isolates Aspergillus terreus (C10) and A. flavus (G1) were selected based on their ability to degrade BPA with percentage 50% and 40% respectively. The effect of different conditions on BPA degradation by (C10) and (G1) including nitrogen sources, incubation temperatures, pH and incubation periods were studied. The highest degradation amount of BPA was obtained from isolates (C10) and (G1) using medium containing sodium nitrate at pH 5 and Yeast extract at pH 7 respectively and incubation temp at 30ºC after incubation at 6 days at shaking state. According to GC-mass the BPA degradation products were identified as following compounds; Thiopropionamide, Methanone, (3-amino-2- benzofuryle) (4- chlorophenyle), 1H-pyrazole, 4,5-dihydro-5,5-dimrthyle-4-isoprpylidene, Phenol, 2,4-isopropylidenedi, Phenol, 2,6-bis(1,1-dimethylethyle)-4- (1-methyle-1-phenylethyle), Bis (2-ethylehexyle) phthalate. The toxicity of BPA was reduced after metabolized by selected fungal strains. Toxicity reduction was measured on cell viability of mammalian cell line.

Conclusion: Our results showed that Aspergillus terreus and A. flavus, have ability to degrade BPA and alter it to less toxic products. These products were tested for their toxicity by cytotoxicity test; the test showed hopeful results while compared it with the toxicity of the original compound.

Open Access Original Research Article

Evaluation of Ten Elite Nigerian Cassava (Manihot esculenta Crantz) Cultivars for Somatic Embryogenesis and Regeneration Potentials

F. A. Nkaa, E. E. Ene-Obong, N. J. Taylor, C. M. Fauquet, C. N. Egesi

Journal of Advances in Biology & Biotechnology, Page 133-143
DOI: 10.9734/JABB/2015/13837

Development of an efficient regeneration system is one of the basic requirements for cassava genetic transformation. Ten elite Nigerian cassava cultivars consisting of seven improved genotypes and three local landraces were evaluated for their ability to produce somatic embryos in vitro. Responses of these cassava cultivars were compared with that of a model cultivar TMS 60444 known for its potential in somatic embryo production. Somatic embryogenesis in cassava is variety dependent probably due to its recalcitrant nature to in vitro manipulations. Production of somatic embryos in cassava is of two kinds – organized embryogenic structure (OES) and friable embryogenic callus (FEC). All the ten cassava cultivars screened produced organized embryogenic structures on DKW induction medium supplemented with 20 g/l sucrose, 8 g/l Difco noble agar and 50 µM Picloram. Friable embryogenic callus generation in cassava is usually achieved by subsequent transfer of the high quality OES formed to another induction medium Gresshoff and Doy (GD) medium supplemented with 20 g/l sucrose, 50 µM Picloram and solidified with 8 g/l Difco noble agar. Out of the ten cassava cultivars screened only four possessed the capacity for FEC production. Among the ten cassava cultivars screened for somatic embryogenesis, more than half of them had the potential for plantlet regeneration from the two types of somatic embryos.

Open Access Review Article

Current Global Status of Dengue Diagnostics

Miranda D. Smith, Azliyati Azizan

Journal of Advances in Biology & Biotechnology, Page 79-95
DOI: 10.9734/JABB/2015/14505

Aims: Dengue Virus is a re-emerging infectious disease that is transmitted through mosquitos. Dengue is a significant health concern because of the number of people it affects globally. Clinical diagnosis of dengue is not possible because the symptoms are similar to other febrile-diseases. Therefore, the only way to truly diagnose dengue is via laboratory methods. Many diagnostics tests exist to accomplish this; however, these tests have disadvantages. Rapid, point-of-care, commercially available diagnostic test kits have come onto the market to bridge the gap for those without high tech laboratories and personnel.  This paper extends the knowledge of a meta-analysis conducted in 2011 on the performance of commercially available diagnostic tests. The purpose of this review was to compare and contrast the accuracy of commercial dengue diagnostic tests.

Study Design:  Systematic Review and Analysis.

Place and Duration of Study: Department of Global Health, University of South Florida, Tampa, Florida, USA between August 2013 and July 2014.

Methodology: A literature review was conducted using multiple database searches using the search terms “dengue diagnostics” and “evaluation”.

Results: Only articles written in English evaluating the accuracy, via sensitivity and specificity, of commercially available diagnostics tests were included. Fifteen articles and a meta-analysis were included in this paper for review. Many diagnostic tests were evaluated in these articles. Bio-Rad’s STRIP was the most evaluated test. Most tests were evaluated once in a country which doesn’t create enough reliability to make any inferences. The best performing test across all studies and countries seems to be Bio-Rad’s NS1 STRIP.

Conclusion: Overall, these tests perform fairly well and more evaluation needs to occur to get a better idea of the true accuracy of the test.

Open Access Review Article

Mushroom Biotechnology in Nigeria–implications for Food Security, Environment and Public Health, A Review

U. K. Asemota, V. A. Etim, O. E. Okereke, S. Abubakar, G. H. Ogbadu

Journal of Advances in Biology & Biotechnology, Page 96-108
DOI: 10.9734/JABB/2015/14197

Mushroom biotechnology is one of the three aspects of mushroom science which has to do with mushroom products and involves the application of the principles of fermentation technology, mushroom biology/microbiology and bioprocess. It is the application of modern biotechnology in mushroom production whose products increase resistance to disease in humans and also balances nutrients in diet and enhancing of the immune system. Determination of genetic diversity and similarity using genetic molecular tools such as Deoxyribonucleic acid (DNA) finger printing, random amplified polymorphic DNA(RAPD) markers, deoxyribonucleic acid(DNA) sequence analysis, the determination of mating type patterns and improved strain selection, solid state and submerged fermentations are all biotechnologically – driven. Worldwide, there is a constantly growing popularity of mushrooms and the tremendously increased use for mushroom products in commercially significant amounts, this makes it very essential to apply biotechnological techniques in the large scale production of mushrooms. This will result in a detailed, reliable and accurate identification and  classsification of mushroom species which is a valuable tool in the cultivation of mushrooms for higher yields and  improve on consumer preferred qualities such as shape, size, texture, shelf-life, nutrient content and resistance to adverse environments, pests and diseases. This review therefore  seeks to highlight  the major biotechnological techniques employed in the production of mushroom products such as nutraceuticals  and current fermentation principles and its effect on sustained access to adequate food and nutrition and a cleaner ecosystem and better  health.