scholarly journals Detailed characterization of the substrate specificity of mouse wax synthase.

2013 ◽  
Vol 60 (2) ◽  
Author(s):  
Magdalena Miklaszewska ◽  
Adam Kawiński ◽  
Antoni Banaś

Wax synthases are membrane-associated enzymes catalysing the esterification reaction between fatty acyl-CoA and a long chain fatty alcohol. In living organisms, wax esters function as storage materials or provide protection against harmful environmental influences. In industry, they are used as ingredients for the production of lubricants, pharmaceuticals, and cosmetics. Currently the biological sources of wax esters are limited to jojoba oil. In order to establish a large-scale production of desired wax esters in transgenic high-yielding oilseed plants, enzymes involved in wax esters synthesis from different biological resources should be characterized in detail taking into consideration their substrate specificity. Therefore, this study aims at determining the substrate specificity of one of such enzymes -- the mouse wax synthase. The gene encoding this enzyme was expressed heterologously in Saccharomyces cerevisiae. In the in vitro assays (using microsomal fraction from transgenic yeast), we evaluated the preferences of mouse wax synthase towards a set of combinations of 11 acyl-CoAs with 17 fatty alcohols. The highest activity was observed for 14:0-CoA, 12:0-CoA, and 16:0-CoA in combination with medium chain alcohols (up to 5.2, 3.4, and 3.3 nmol wax esters/min/mg microsomal protein, respectively). Unsaturated alcohols longer than 18°C were better utilized by the enzyme in comparison to the saturated ones. Combinations of all tested alcohols with 20:0-CoA, 22:1-CoA, or Ric-CoA were poorly utilized by the enzyme, and conjugated acyl-CoAs were not utilized at all. Apart from the wax synthase activity, mouse wax synthase also exhibited a very low acyl-CoA:diacylglycerol acyltransferase activity. However, it displayed neither acyl-CoA:monoacylglycerol acyltransferase, nor acyl-CoA:sterol acyltransferase activity.

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1288
Author(s):  
Wendy Dong ◽  
Boris Kantor

CRISPR/Cas technology has revolutionized the fields of the genome- and epigenome-editing by supplying unparalleled control over genomic sequences and expression. Lentiviral vector (LV) systems are one of the main delivery vehicles for the CRISPR/Cas systems due to (i) its ability to carry bulky and complex transgenes and (ii) sustain robust and long-term expression in a broad range of dividing and non-dividing cells in vitro and in vivo. It is thus reasonable that substantial effort has been allocated towards the development of the improved and optimized LV systems for effective and accurate gene-to-cell transfer of CRISPR/Cas tools. The main effort on that end has been put towards the improvement and optimization of the vector’s expression, development of integrase-deficient lentiviral vector (IDLV), aiming to minimize the risk of oncogenicity, toxicity, and pathogenicity, and enhancing manufacturing protocols for clinical applications required large-scale production. In this review, we will devote attention to (i) the basic biology of lentiviruses, and (ii) recent advances in the development of safer and more efficient CRISPR/Cas vector systems towards their use in preclinical and clinical applications. In addition, we will discuss in detail the recent progress in the repurposing of CRISPR/Cas systems related to base-editing and prime-editing applications.


2006 ◽  
Vol 398 (3) ◽  
pp. 531-538 ◽  
Author(s):  
Yukiko Mizutani ◽  
Akio Kihara ◽  
Yasuyuki Igarashi

The LASS (longevity assurance homologue) family members are highly conserved from yeasts to mammals. Five mouse and human LASS family members, namely LASS1, LASS2, LASS4, LASS5 and LASS6, have been identified and characterized. In the present study we cloned two transcriptional variants of hitherto-uncharacterized mouse LASS3 cDNA, which encode a 384-amino-acid protein (LASS3) and a 419-amino-acid protein (LASS3-long). In vivo, [3H]dihydrosphingosine labelling and electrospray-ionization MS revealed that overproduction of either LASS3 isoform results in increases in several ceramide species, with some preference toward those having middle- to long-chain-fatty acyl-CoAs. A similar substrate preference was observed in an in vitro (dihydro)ceramide synthase assay. These results indicate that LASS3 possesses (dihydro)ceramide synthesis activity with relatively broad substrate specificity. We also found that, except for a weak display in skin, LASS3 mRNA expression is limited almost solely to testis, implying that LASS3 plays an important role in this gland.


2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Xuan Guan ◽  
David L Mack ◽  
Claudia M Moreno ◽  
Fernando Santana ◽  
Charles E Murry ◽  
...  

Introduction: Human somatic cells can be reprogrammed into primitive stem cells, termed induced pluripotent stem cells (iPSCs). These iPSCs can be extensively expanded in vitro and differentiated into multiple functional cell types, enabling faithful preservation of individual’s genotype and large scale production of disease targeted cellular components. These unique cellular reagents thus hold tremendous potential in disease mechanism study, drugs screening and cell replacement therapy. Due to the genetic mutation of the protein dystrophin, many DMD patients develop fatal cardiomyopathy with no effective treatment. The underlying pathogenesis has not been fully elucidated. Hypothesis: We tested the hypothesis that iPSCs could be generated from DMD patients’ urine samples and differentiated into cardiomyocytes, recapitulating the dystrophic phenotype. Methods: iPSCs generation was achieved by introducing a lentiviral vector expressing Oct4, Sox2, c-Myc and Klf4 into cells derived from patient’s (n=1) and healthy volunteers’ (n=3) urine. Cardiomyocytes were derived by sequentially treating iPSCs with GSK3 inhibitor CHIR99021 and Wnt inhibitor IWP4. Differentiated cardiomyocytes were subjected to calcium imaging, electrophysiology recording, Polymerase Chain Reaction (PCR) analysis, and immunostaining. Results: iPSCs were efficiently generated from human urine samples and further forced to differentiate into contracting cardiomyocytes. PCR analysis and immunostaining confirmed the expression of a panel of cardiac markers. Both normal and patient iPSC derived cardiomyocytes exhibited spontaneous and field stimulated calcium transients (up to 2Hz), as well as action potentials with ventricular-like and nodal-like characteristics. Anti-dystrophin antibodies stained normal iPSC-derived cardiomyocyte membranes but did not react against DMD iPSC-derived cardiomyocytes. Conclusions: Cardiomyocytes can be efficiently generated from human urine, through the cellular reprogramming technology. DMD cardiomyocytes retained the patient’s genetic information and manifested a dystrophin-null phenotype. Functional assessments are underway to determine differences that may exist between genotypes.


2014 ◽  
Vol 69 ◽  
pp. 21-27 ◽  
Author(s):  
Valeria Cavallaro ◽  
Cristina Patanè ◽  
Salvatore L. Cosentino ◽  
Isabella Di Silvestro ◽  
Venera Copani

2018 ◽  
Vol 24 (1) ◽  
pp. 79-95 ◽  
Author(s):  
Christian Lohasz ◽  
Nassim Rousset ◽  
Kasper Renggli ◽  
Andreas Hierlemann ◽  
Olivier Frey

Microphysiological systems hold the promise to increase the predictive and translational power of in vitro substance testing owing to their faithful recapitulation of human physiology. However, the implementation of academic developments in industrial settings remains challenging. We present an injection-molded microfluidic microtissue (MT) culture chip that features two channels with 10 MT compartments each and that was designed in compliance with microtiter plate standard formats. Polystyrene as a chip material enables reliable, large-scale production and precise control over experimental conditions due to low adsorption or absorption of small, hydrophobic molecules at or into the plastic material in comparison with predecessor chips made of polydimethylsiloxane. The chip is operated by tilting, which actuates gravity-driven flow between reservoirs at both ends of every channel, so that the system does not require external tubing or pumps. The flow rate can be modulated by adjusting the tilting angle on demand. The top-open design of the MT compartment enables efficient MT loading using standard or advanced pipetting equipment, ensures oxygen availability in the chip, and allows for high-resolution imaging. Every channel can be loaded with up to 10 identical or different MTs, as demonstrated by culturing liver and tumor MTs in the same medium channel on the chip.


1985 ◽  
Vol 5 (7) ◽  
pp. 1795-1799
Author(s):  
D R Kaplan ◽  
B Bockus ◽  
T M Roberts ◽  
J Bolen ◽  
M Israel ◽  
...  

A recombinant plasmid containing a metallothionein promoter-polyoma middle T cDNA fusion was constructed and used to transfect NIH 3T3 cells. Transformed cells expressing middle T were injected into nude mice. Within 3 weeks, each mouse produced tumors containing middle T equivalent to that in 250 to 1,000 100-mm dishes of polyomavirus-infected cells. This middle T, partially purified by immunoaffinity chromatography, retained activity as measured by its ability to be phosphorylated in vitro. The combined approach of fusing strong promoters to genes of interest and utilizing nude mice to grow large quantities of cells expressing the gene provides a quick, inexpensive alternative to other expression systems.


2017 ◽  
Vol 9 (3) ◽  
pp. 371-377
Author(s):  
Charles Oluwaseun ADETUNJI ◽  
Julius Kola OLOKE ◽  
Gandham PRASAD ◽  
Moses ABALAKA ◽  
Emenike Onyebum IROKANULO

Formulation of effective and environmental friendly bioherbicides depends on the type of fermentation medium used for the production of phytotoxic metabolites. The effect of biomass, colony forming unit and the phytotoxic metabolite produced from the biphasic fermentation was carried out, while the phytotoxic metabolite was  tested in vivo and in-vitro on Echinochola crus-galli and dicotyledonous Chromolaena odorata. The mutant strain of Lasiodiplodia pseudotheobromae C1136 (Lp90) produced the highest amount of conidia and the largest necrotic area on the two tested weeds when compared to its wild strain in the different biphasic media combinations. The study revealed that the biphasic system containing PDB + rice produced the highest bioherbicidal activities. Therefore, the phytotoxic metabolites from strain C1136 are suggested for large scale production of bioherbicides for the management of weeds in conventional farming to improve yield and enhance food security.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Sadaf Vahdat ◽  
Sara Pahlavan ◽  
Elena Mahmoudi ◽  
Maryam Barekat ◽  
Hassan Ansari ◽  
...  

Abstract Cardiovascular progenitor cells (CPCs) derived from human pluripotent stem cells (hPSCs) are proposed to be invaluable cell sources for experimental and clinical studies. This wide range of applications necessitates large-scale production of CPCs in an in vitro culture system, which enables both expansion and maintenance of these cells. In this study, we aimed to develop a defined and efficient culture medium that uses signaling factors for large-scale expansion of early CPCs, called cardiogenic mesodermal cells (CMCs), which were derived from hPSCs. Chemical screening resulted in a medium that contained a reproducible combination of three factors (A83-01, bFGF, and CHIR99021) that generated 1014 CMCs after 10 passages without the propensity for tumorigenicity. Expanded CMCs retained their gene expression pattern, chromosomal stability, and differentiation tendency through several passages and showed both the safety and possible cardio-protective potentials when transplanted into the infarcted rat myocardium. These CMCs were efficiently cryopreserved for an extended period of time. This culture medium could be used for both adherent and suspension culture conditions, for which the latter is required for large-scale CMC production. Taken together, hPSC-derived CMCs exhibited self-renewal capacity in our simple, reproducible, and defined medium. These cells might ultimately be potential, promising cell sources for cardiovascular studies.


2020 ◽  
Vol 8 (1) ◽  
pp. 54-68
Author(s):  
Meena Maiya Suwal ◽  
Janardan Lamichhane ◽  
Dhurva Prasad Gauchan

Micropropagation is an alternative technique to propagate at large scale plants to meet global plant demand. Various researchers have worked on the micropropagation technique to regenerate bamboo species by using nodal segments from years. Contamination, browning, necrosis, and acclimatization with physiological stress are the extreme problems of the micropropagation technique. But, many numbers of papers have been published on micropropagation of the bamboo species through nodal segments as explants. The proliferation of the bamboo shoots is dependent on the season of collection, size of explants, the position of explants, diversity of plants, concentration and combination of plant growth regulators, most adequate culture medium, environmental condition of the equipment, handling, and individual species. Bamboo is a monocarpic fast-growing, tall perennial grass and having the high potential to generate economic and social benefits. It helps to maintain land patterns and control soil erosion.  The long life cycle of the bamboo produces a huge amount of seeds but unfortunately, mostly, they are non-viable. So, bamboos are propagated from vegetative by cutting and air layering. However, these methods are only for a small scale and they also tend to destroy large mother plant stocks and difficult to be transported. So, the in vitro propagation technique is useful to obtain large progenies from desired genotypes. Mostly, BAP and TDZ growth hormones are widely used for shoot multiplication and IBA, NAA and IAA are used for root initiation as per developed protocols in tissue culture for large scale production. This review intends to explore an overview of the recent literature reports to summarize the importance of micropropagation by using nodal segments of bamboo species and factors influencing it.


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