In Vivo and in Vitro Degradation of Urea and Uric Acid by Encapsulated Genetically Modified Microorganisms

2004 ◽  
Vol 10 (9) ◽  
pp. 1446-1455
Author(s):  
Jill A. O'Loughlin ◽  
Jan M. Bruder ◽  
Michael J. Lysaght
2021 ◽  
Vol 17 (10) ◽  
pp. 2071-2084
Author(s):  
Tianjiao Han ◽  
Meiying Wang ◽  
Wenchao Li ◽  
Mingxing An ◽  
Hongzheng Fu

Uric acid is the final product of purine metabolism, and excessive serum uric acid can cause gouty arthritis and uric acid nephropathy. Therefore, lowering the uric acid level and alleviating inflammation in the body are the key points to treating these diseases. A stable nanosuspension of peptide BmK9 was prepared by the precipitation-ultrasonication method. By combining uricase on the surface of a positively charged carrier, a complex consisting of neutral rod-shaped BmK9 and uricase nanoparticles (Nplex) was formed to achieve the delivery of BmK9 and uricase, respectively. The formulation of Nplex has a diameter of 180 nm and drug loading up to 200%, which releases BmK9 and uricase slowly and steadily in drug release tests in vitro. There was significantly improved pharmacokinetic behavior of the two drugs because Nplex prolonged the half-life and increased tissue accumulation. Histological assessments showed that the dual drug Nplex can reduce the inflammation response in acute gouty arthritis and chronic uric acid nephropathy in vivo. In the macrophage system, there was lower toxicity and increased beneficial effect on inflammation with Nplex than free BmK9 or uricase. Collectively, this novel formulation provides a dual drug delivery system that can treat gouty arthritis and uric acid nephropathy.


2010 ◽  
Vol 404 (2) ◽  
pp. 149-154 ◽  
Author(s):  
F.N. Rozov ◽  
T.S. Grinenko ◽  
G.L. Levit ◽  
V.P. Krasnov ◽  
A.V. Belyavsky

2011 ◽  
Vol 23 (1) ◽  
pp. 263
Author(s):  
F. Pereyra-Bonnet ◽  
A. Gibbons ◽  
M. Cueto ◽  
R. Bevacqua ◽  
L. Escobar ◽  
...  

Microinjection of DNA into the male pronucleus is a commonly used method to generate transgenic animals. However, it is only moderately efficient in several species because it requires proper male pronuclear visualisation, which occurs only in a narrow window of time in mice. The cytoplasmic microinjection of exogenous DNA (eDNA) is an alternative method that has not been fully investigated. Our objective was to evaluate if cytoplasmic microinjection of eDNA is capable of producing genetically modified embryos. In vitro and in vivo derived sheep embryos were cytoplasmically microinjected with pCX-EGFP previously incubated (5 min in a PVP droplet) with oolemma-cytoplasm fragments obtained from donor oocytes by microsurgery. A control group using microinjected plasmid alone was included in the in vivo procedure. For in vitro microinjection, IVF embryos were microinjected with circular plasmid with promoter (50 or 500 ng μL–1) or without promoter (50 ng μL–1) at 6 h after fertilization. The IVF was performed following (Brackett and Olliphant 1975 Biol. Reprod. 12, 260–274) with 15 × 106 spermatozoa mL–1, and presumptive zygotes were cultured in SOF. The expression of enhance green fluorescent protein (EGFP) was determined under blue light. For in vivo microinjection, embryos from superovulated sheep (by standard procedures) were recovered and microinjected with 50 ng μL–1 of linearized plasmid without promoter at 12 h after laparoscopic insemination with frozen semen (100 × 106 spermatozoa per sheep). Plasmid without promoter was used to avoid any possible cytotoxic effect produced by EGFP expression. The microinjection of IVF embryos with 50 ng μL–1 of plasmid was the best condition to produce embryos expressing eDNA (n = 96; 46.9% cleaved; 12.2% blastocysts; 53.0 and 4.1% of green embryos and blastocysts, respectively). Variables between the groups with or without promoter IVF were not statistically different (Fisher test: P < 0.05); however, when 500 ng μL–1 was microinjected, no blastocysts were obtained. In the in vivo embryo production group, 111 presumptive zygotes were microinjected (n = 37; with plasmid alone) from 16 donor sheep (11.5 ± 4.0 corpora lutea; 8.4 ± 4.8 presumptive zygotes recovered; 74.3% recovery rate). The mean time from injection to cleavage was 18.0 ± 4.5 h, and the percentage of cleavage and damage (due to the embryo injection) were >70% and <10%, respectively. Fifty-eight good quality embryos were transferred into the oviducts of 19 surrogate ewes; 12 of them are pregnant (63.1%). The presence of green IVF embryos demonstrates that eDNA was transported to the nucleus after cytoplasmic injection. We believe that the multi-fold increase (50- to 100-fold) in plasmid concentration compared with that used by others was the key step to our successful cytoplasmic microinjection. Accordingly, the new/old methodology described in this study provides an easy DNA construct delivery system of interest for the implementation of early reprogramming events. In addition, results obtained in the near future using in vivo cytoplasmic microinjection with high concentrations of eDNA could revalidate this technique for producing genetically modified large animals.


2019 ◽  
Vol 286 (1914) ◽  
pp. 20191833 ◽  
Author(s):  
Joseph D. Madison ◽  
Scot P. Ouellette ◽  
Emme L. Schmidt ◽  
Jacob L. Kerby

Ongoing investigations into the interactions between microbial communities and their associated hosts are changing how emerging diseases are perceived and ameliorated. Of the numerous host–microbiome–disease systems of study, the emergence of chytridiomycosis (caused by Batrachochytrium dendrobatidis , hereafter Bd ) has been implicated in ongoing declines and extinction events of amphibians worldwide. Interestingly, there has been differential survival among amphibians in resisting Bd infection and subsequent disease. One factor thought to contribute to this resistance is the host-associated cutaneous microbiota. This has raised the possibility of using genetically modified probiotics to restructure the host-associated microbiota for desired anti-fungal outcomes. Here, we use a previously described strain of Serratia marcescens ( Sm ) for the manipulation of amphibian cutaneous microbiota. Sm was genetically altered to have a dysfunctional pathway for the production of the extracellular metabolite prodigiosin. This genetically altered strain (Δ pig ) and the functional prodigiosin producing strain (wild-type, WT) were compared for their microbial community and anti- Bd effects both in vitro and in vivo . In vitro , Bd growth was significantly repressed in the presence of prodigiosin. In vivo , the inoculation of both Sm strains was shown to significantly influence amphibian microbiota diversity with the Δ pig-Sm treatment showing increasing alpha diversity, and the WT- Sm having no temporal effect on diversity. Differences were also seen in host mortality with Δ pig-Sm treatments exhibiting significantly decreased survival probability when compared with WT- Sm in the presence of Bd . These results are an important proof-of-concept for linking the use of genetically modified probiotic bacteria to host microbial community structure and disease outcomes, which in the future may provide a way to ameliorate disease and address critical frontiers in disease and microbial ecology.


Author(s):  
Sri Ningsih ◽  
Fahri Fahrudin

 Objective: Hyperuricemia (high uric acid levels) prevalence increased year by year. This study was aimed to elaborate the in vitro xanthine oxidase (XO) inhibitory activity and in vivo lowering hyperuricemic effect of Uncaria gambir (Hunter) Roxb) (gambir), Caesalpinia sappan L. (secang) and the combined extract of secang and gambir (formulae extract [FE]).Methods: Gambir and secang extracts were prepared by maceration with ethanol and FE was the proportioned combination of these two extracts. XO inhibitory activity was determined by measuring the formation of uric acid in the xanthine/XO system in vitro using allopurinol as a positive control at 100 ug/mL. Antioxidant activity was by 1,1-diphenyl-2-picrylhydrazyl radical reducing methods. The in vivo experiments were conducted in the oxonate-induced hyperuricemia rat model, in which FE was gavaged p.o. at the arrange dose of 75, 150, and 300 mg/kg bw for 2 weeks. Polyphenol content was measured using Folin–Ciocalteu reagent spectrophotometrically.Results: The XO inhibitory activity of FE was 80% of allopurinol, while secang and gambir were 98% and 50%, respectively. The strength was appropriate to the total polyphenol content, in which it decreased in the order of secang (99%) > FE (86%) > gambir (46%). Furthermore, FE at all tested doses was able to decrease uric acid levels. FE also demonstrated antioxidant activity with a value of 74% relative to Vitamin C at 4 ug/mL.Conclusion: These studies could be concluded that FE exhibited the ability to decrease uric acid level so that it was potential to be developed further as a uric acid-lowering agent.


2015 ◽  
Vol 83 (9) ◽  
pp. 3526-3533 ◽  
Author(s):  
Adrienne W. Paton ◽  
Austen Y. Chen ◽  
Hui Wang ◽  
Lauren J. McAllister ◽  
Florian Höggerl ◽  
...  

Shiga-toxigenicEscherichia coli(STEC) causes severe gastrointestinal infections in humans that may lead to life-threatening systemic sequelae, such as the hemolytic uremic syndrome (HUS). Rapid diagnosis of STEC infection early in the course of disease opens a window of opportunity for therapeutic intervention, for example, by administration of agents that neutralize Shiga toxin (Stx) in the gut lumen. We previously developed a recombinant bacterium that expresses a mimic of the Stx receptor globotriaosyl ceramide (Gb3) on its surface through modification of the lipopolysaccharide (A. W. Paton, R. Morona, and J. C. Paton, Nat Med6:265–270, 2000,http://dx.doi.org/10.1038/73111). This construct was highly efficaciousin vivo, protecting mice from otherwise fatal STEC disease, but the fact that it is a genetically modified organism (GMO) has been a barrier to clinical development. In the present study, we have overcome this issue by development of Gb3 receptor mimic bacterial ghosts (BGs) that are not classified as GMOs. Gb3-BGs neutralized Stx1 and Stx2in vitrowith high efficiency, whereas alternative Gb3-expressing non-GMO subbacterial particles (minicells and outer membrane blebs) were ineffective. Gb3-BGs were highly efficacious in a murine model of STEC disease. All mice (10/10) treated with Gb3-BGs survived challenge with a highly virulent O113:H21 STEC strain and showed no pathological signs of renal injury. In contrast, 6/10 mice treated with control BGs succumbed to STEC challenge, and survivors exhibited significant weight loss, neutrophilia, and histopathological evidence of renal damage. Thus, Gb3-BGs offer a non-GMO approach to treatment of STEC infection in humans, particularly in an outbreak setting.


2014 ◽  
Vol 33 (4-6) ◽  
pp. 192-198 ◽  
Author(s):  
Tamaki Watanabe ◽  
Naoko H. Tomioka ◽  
Shigekazu Watanabe ◽  
Masao Tsuchiya ◽  
Makoto Hosoyamada
Keyword(s):  

1983 ◽  
Vol 61 (11) ◽  
pp. 1153-1157 ◽  
Author(s):  
James D. Moyer ◽  
J. Frank Henderson

Hypoxanthine is an inefficient precursor of purine nucleotides in mouse tissues. In vitro, mouse erythrocytes salvage <10% of hypoxanthine (10 μM) added to whole blood in 30 min of incubation at 37 °C. In vivo, circulating hypoxanthine is rapidly degraded (>90% in 10 min) to allantoin and uric acid. All tissues examined (other than erythrocytes) converted small amounts of hypoxanthine to nucleotides, with kidney and lung being the most active tissues examined. It is estimated that <2% of circulating hypoxanthine is salvaged in the mouse; the remainder is catabolized.


2008 ◽  
Vol 106 (3) ◽  
pp. 1225-1233 ◽  
Author(s):  
Carlos A. Montoya ◽  
Arturo S. Gomez ◽  
Jean-Paul Lallès ◽  
Wolfgang B. Souffrant ◽  
Stephen Beebe ◽  
...  

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