Mitochondrial Neurogastrointestinal Encephalomyopathy (MNGIE): Biochemical Features and Therapeutic Approaches

2007 ◽  
Vol 27 (1-3) ◽  
pp. 151-163 ◽  
Author(s):  
M. C. Lara ◽  
M. L. Valentino ◽  
J. Torres-Torronteras ◽  
M. Hirano ◽  
R. Martí
Keyword(s):  
Molecular Genetic ◽  
In Vivo Studies ◽  
Gene Encoding ◽  
Mitochondrial Neurogastrointestinal Encephalomyopathy ◽  
Mtdna Replication ◽  
Biochemical Features

Over the last 15 years, important research has expanded our knowledge of the clinical, molecular genetic, and biochemical features of mitochondrial neurogastrointestinal encephalomyopathy (MNGIE). The characterization of mitochondrial involvement in this disorder and the seminal determination of its genetic cause, have opened new possibilities for more detailed and deeper studies on the pathomechanisms in this progressive and fatal disease. It has been established that MNGIE is caused by mutations in the gene encoding thymidine phosphorylase (TP), which lead to absolute or nearly complete loss of its catalytic activity, producing systemic accumulations of its substrates, thymidine (dThd) and deoxyuridine (dUrd). Findings obtained from in vitro and in vivo studies indicate that the biochemical imbalances specifically impair mitochondrial DNA (mtDNA) replication, repair, or both leading to mitochondrial dysfunction. We have proposed that therapy for MNGIE should be aimed at reducing the concentrations of these toxic nucleosides to normal or nearly normal levels. The first treatment, allogeneic stem-cell transplantation (alloSCT) reported in 2006, produced a nearly full biochemical correction of the dThd and dUrd imbalances in blood. Clinical follow-up of this and other patients receiving alloSCT is necessary to determine whether this and other therapies based on a permanent restoration of TP will be effective treatment for MNGIE.

scholarly journals Characterization of a New Chitosanase from a Marine Bacillus sp. and the Anti-Oxidant Activity of Its Hydrolysate

Marine Drugs ◽  
2020 ◽  
Vol 18 (2) ◽  
pp. 126
Author(s):  
Chunrui Ma ◽  
Xiao Li ◽  
Kun Yang ◽  
Shangyong Li
Keyword(s):  
Radical Scavenging ◽  
Maximal Activity ◽  
Hydroxyl Groups ◽  
Bacillus Sp ◽  
Low Molecular Weight Chitosan ◽  
Anti Oxidant

Chitooligosaccharide (COS) has been recognized to exhibit efficient anti-oxidant activity. Enzymatic hydrolysis using chitosanases can retain all the amino and hydroxyl groups of chitosan, which are necessary for its activity. In this study, a new chitosanase encoding gene, csnQ, was cloned from the marine Bacillus sp. Q1098 and expressed in Escherichia coli. The recombinant chitosanase, CsnQ, showed maximal activity at pH 5.31 and 60 °C. Determination of CsnQ pH-stability showed that CsnQ could retain more than 50% of its activity over a wide pH, from 3.60 to 9.80. CsnQ is an endo-type chitosanase, yielding chitodisaccharide as the main product. Additionally, in vitro and in vivo analyses indicated that chitodisaccharide possesses much more effective anti-oxidant activity than glucosamine and low molecular weight chitosan (LMW-CS) (~5 kDa). Notably, to our knowledge, this is the first evidence that chitodisaccharide is the minimal COS fragment required for free radical scavenging.

scholarly journals Yeast as a Model to Understand Actin-Mediated Cellular Functions in Mammals—Illustrated with Four Actin Cytoskeleton Proteins

Cells ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 672 ◽  
Author(s):  
Zain Akram ◽  
Ishtiaq Ahmed ◽  
Heike Mack ◽  
Ramandeep Kaur ◽  
Richard C. Silva ◽  
...  
Keyword(s):  
Actin Cytoskeleton ◽  
Molecular Mechanisms ◽  
Budding Yeast ◽  
Animal Cell ◽  
Molecular Genetic ◽  
In Vivo Studies ◽  
Yeast Saccharomyces Cerevisiae ◽  
Higher Eukaryotes

The budding yeast Saccharomyces cerevisiae has an actin cytoskeleton that comprises a set of protein components analogous to those found in the actin cytoskeletons of higher eukaryotes. Furthermore, the actin cytoskeletons of S. cerevisiae and of higher eukaryotes have some similar physiological roles. The genetic tractability of budding yeast and the availability of a stable haploid cell type facilitates the application of molecular genetic approaches to assign functions to the various actin cytoskeleton components. This has provided information that is in general complementary to that provided by studies of the equivalent proteins of higher eukaryotes and hence has enabled a more complete view of the role of these proteins. Several human functional homologues of yeast actin effectors are implicated in diseases. A better understanding of the molecular mechanisms underpinning the functions of these proteins is critical to develop improved therapeutic strategies. In this article we chose as examples four evolutionarily conserved proteins that associate with the actin cytoskeleton: (1) yeast Hof1p/mammalian PSTPIP1, (2) yeast Rvs167p/mammalian BIN1, (3) yeast eEF1A/eEF1A1 and eEF1A2 and (4) yeast Yih1p/mammalian IMPACT. We compare the knowledge on the functions of these actin cytoskeleton-associated proteins that has arisen from studies of their homologues in yeast with information that has been obtained from in vivo studies using live animals or in vitro studies using cultured animal cell lines.

Development and characterization of highly selective target-sensitive liposomes for the delivery of streptokinase: in vitro/in vivo studies

Drug Delivery ◽  
2014 ◽  
Vol 23 (3) ◽  
pp. 791-797 ◽  
Author(s):  
Bhuvaneshwar Vaidya ◽  
Manasa K. Nayak ◽  
Debabrata Dash ◽  
Govind P. Agrawal ◽  
Suresh P. Vyas
Keyword(s):  
In Vivo Studies ◽  
Selective Target

Characterization of nociceptin receptors in the periphery: in vitro and in vivo studies

1999 ◽  
Vol 359 (3) ◽  
pp. 160-167 ◽  
Author(s):  
Raffaella Bigoni ◽  
Sandro Giuliani ◽  
G. Calo’ ◽  
Anna Rizzi ◽  
Remo Guerrini ◽  
...  
Keyword(s):  
In Vivo Studies

Determination of major metabolites of MAM-2201 and JWH-122 in in vitro and in vivo studies to distinguish their intake

2014 ◽  
Vol 244 ◽  
pp. 85-91 ◽  
Author(s):  
Moonhee Jang ◽  
Ilchung Shin ◽  
Wonkyung Yang ◽  
Hyejin Chang ◽  
Hye Hyun Yoo ◽  
...  
Keyword(s):  
In Vivo Studies

scholarly journals ENHANCED FLUORESCENCE IMAGING WITH DMSO-MEDIATED OPTICAL CLEARING

2010 ◽  
Vol 03 (03) ◽  
pp. 153-158 ◽  
Author(s):  
SANJEEV KARMA ◽  
JAMES HOMAN ◽  
CHARLES STOIANOVICI ◽  
BERNARD CHOI
Keyword(s):  
Fluorescence Emission ◽  
Model Systems ◽  
In Vivo Studies ◽  
In Vivo Model ◽  
Fluorescence Signal ◽  
Optical Clearing ◽  
Treated Site

Recent studies have demonstrated that topical application of glycerol on intact skin does not affect its optical scattering properties. Investigators from our research group recently revisited the use of dimethyl sulfoxide (DMSO) as an agent with optical clearing potential. We address the use of optical clearing to enhance quantitation of subsurface fluorescence emission. We employed both in vitro and in vivo model systems to study the effect of topical DMSO application on fluorescence emission. Our in vitro experiments performed on a tissue-simulating phantom suggest that DMSO-mediated optical clearing enables enhanced characterization of subsurface fluorophores. With topical DMSO application, a marked increase in fluorescence emission was observed. After 30 min, the fluorescence signal at the DMSO-treated site was 9× greater than the contralateral saline-treated site. This ratio increased to 13× at 105 min after agent application. In summary, DMSO is an effective optical clearing agent for improved fluorescence emission quantitation and warrants further study in preclinical in vivo studies. Based on outcomes from previous clinical studies on the toxicity profile of DMSO, we postulate that clinical application of DMSO as an optical clearing agent, can be performed safely, although further study is warranted.

scholarly journals Environmental Modulation of Oral Treponeme Virulence in a Murine Model

1999 ◽  
Vol 67 (6) ◽  
pp. 2783-2789 ◽  
Author(s):  
Lakshmyya Kesavalu ◽  
Stanley C. Holt ◽  
Jeffrey L. Ebersole
Keyword(s):  
Lesion Size ◽  
In Vivo Studies ◽  
Iron Availability ◽  
Environmental Alteration ◽  
Induction Kinetics ◽  
Focus Of Infection ◽  
Systemic Manifestations

ABSTRACT This investigation examined the effects of environmental alteration on the virulence of the oral treponemes Treponema denticolaand Treponema pectinovorum. The environmental effects were assessed by using a model of localized inflammatory abscesses in mice. In vitro growth of T. denticola and T. pectinovorum as a function of modification of the cysteine concentration significantly enhanced abscess formation and size. In contrast, growth of T. denticola or T. pectinovorum under iron-limiting conditions (e.g., dipyridyl chelation) had no effect on abscess induction in comparison to that when the strains were grown under normal iron conditions. In vivo modulation of the microenvironment at the focus of infection with Cytodex beads demonstrated that increasing the local inflammation had no effect on lesion induction or size. In vivo studies involved the determination of the effects of increased systemic iron availability (e.g., iron dextran or phenylhydrazine) on the induction, kinetics, and size of lesions. T. denticola induced significantly larger lesions in mice with iron pretreatment and demonstrated systemic manifestations of the infectious challenge and an accompanying spreading lesion with phenylhydrazine pretreatment (e.g., increases in circulating free hemoglobin). In contrast, T. pectinovorum virulence was minimally affected by this in vivo treatment to increase iron availability. T. denticolavirulence, as evaluated by lesion size, was increased additively by in vivo iron availability, and cysteine modified growth of the microorganism. Additionally, galactosamine sensitized mice to a lethal outcome following infection with both T. denticola andT. pectinovorum, suggesting an endotoxin-like activity in these treponemes. These findings demonstrated the ability to modify the virulence capacity of T. denticola andT. pectinovorum by environmental conditions which can be evaluated by using in vivo murine models.

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