Genetic variants of human erythrocyte glucose 6-phosphate dehydrogenase. II. In vitro and in vivo function of the A- variant

Biochemistry ◽  
1971 ◽  
Vol 10 (3) ◽  
pp. 420-423 ◽  
Author(s):  
Lucio Luzzatto ◽  
Adeyinka Afolayan
2001 ◽  
Vol 34 (4) ◽  
pp. 297-302 ◽  
Author(s):  
Mehmet Çiftçi ◽  
İsmail Özmen ◽  
M.Emin Büyükokuroğlu ◽  
Sadrettin Pençe ◽  
Ö.İrfan Küfrevioğlu

2021 ◽  
Vol 12 ◽  
Author(s):  
Kriti Joshi ◽  
Fergus Cameron ◽  
Swasti Tiwari ◽  
Stuart I. Mannering ◽  
Andrew G. Elefanty ◽  
...  

Induced pluripotent stem cell (iPSC) technology is increasingly being used to create in vitro models of monogenic human disorders. This is possible because, by and large, the phenotypic consequences of such genetic variants are often confined to a specific and known cell type, and the genetic variants themselves can be clearly identified and controlled for using a standardized genetic background. In contrast, complex conditions such as autoimmune Type 1 diabetes (T1D) have a polygenic inheritance and are subject to diverse environmental influences. Moreover, the potential cell types thought to contribute to disease progression are many and varied. Furthermore, as HLA matching is critical for cell-cell interactions in disease pathogenesis, any model that seeks to test the involvement of particular cell types must take this restriction into account. As such, creation of an in vitro model of T1D will require a system that is cognizant of genetic background and enables the interaction of cells representing multiple lineages to be examined in the context of the relevant environmental disease triggers. In addition, as many of the lineages critical to the development of T1D cannot be easily generated from iPSCs, such models will likely require combinations of cell types derived from in vitro and in vivo sources. In this review we imagine what an ideal in vitro model of T1D might look like and discuss how the required elements could be feasibly assembled using existing technologies. We also examine recent advances towards this goal and discuss potential uses of this technology in contributing to our understanding of the mechanisms underlying this autoimmune condition.


1998 ◽  
Vol 124 (6) ◽  
pp. 1237-1244 ◽  
Author(s):  
T. Fujita ◽  
K. Suzuki ◽  
T. Tada ◽  
Y. Yoshihara ◽  
R. Hamaoka ◽  
...  

1981 ◽  
Vol 97 (4) ◽  
pp. 491-495 ◽  
Author(s):  
S. Matsuzaki ◽  
M. Suzuki

Abstract. The effect of sodium perchlorate (NaClO4) on the methylthiouracil-induced increase in the activity of thyroid glucose 6-phosphate dehydrogenase (G6PDH), ornithine decarboxylase (ODC) and polyamine contents was studied in the rat. The G6PDH activity was increased nearly three-fold by methylthiouracil (MTU) but not by ClO4- at 7 days of treatment. Perchlorate lowered the MTU-induced enzyme activity to nearly the control level, without changing circulating thyrotrophin (TSH). The anion had no inhibitory effect on G6PDH activity in vitro. The possibility that an inhibitor specific for G6PDH was generated in ClO4- treated rat thyroids was excluded. The activity of ODC was greatly increased by both ClO4- and MTU, the increase being significant as early as on the second day of treatment. Perchlorate had no inhibitory effect on MTU-induced ODC activity in vivo but decreased total contents of spermidine and spermine in the thyroid, without affecting the concentration (nmoles/ g wet weight) of the polyamines. These results suggest that ClO4- acts directly on the thyroid to suppress specifically the stimulatory effect of TSH on G6PDH activity and possibly on polyamine accumulation.


Obesity Facts ◽  
2022 ◽  
Author(s):  
Nadien AbouHashem ◽  
Roan E. Zaied ◽  
Kholoud Al-Shafai ◽  
Mariam Nofal ◽  
Najeeb Syed ◽  
...  

Introduction: Monogenic obesity (MO) is a rare genetic disease characterized by severe early-onset obesity in affected individuals. Previous genetic studies revealed 8 definitive genes for monogenic non-syndromic obesity; many were discovered in consanguineous populations. Here, we examined MO in the Qatari population, whose population is largely consanguineous (54%) and characterized by extensive obesity (45%). Methods: Whole genome sequences of Qatar Biobank samples from 250 subjects with obesity and 250 subjects with normal weight, obtained in association with the Qatar Genome Programme, were searched for genetic variants in the genes known to be associated with MO (i.e., LEP, LEPR, POMC, PCSK1, MC3R, MC4R, MRAP2 and ADCY3). The impact of the variants identified was investigated utilizing in silico tools for prediction in combination with protein visualization by PyMOL. Results: We identified potential MO variants in more than 5% of the cases in our cohort. We revealed 11 rare variants in 6 of the genes targeted, including two disease-causing variants in MC4R and MRAP2, all of which were heterozygous. Moreover, enrichment of a heterozygous ADCY3 variant (c.1658C>T; p.A553V) appeared to cause severe obesity in an autosomal dominant manner. Conclusion: These findings highlight the importance of implementing routine testing for genetic variants that predispose for MO in Qatar. Clearly, additional studies of this nature on populations not yet examined are required. At the same time, functional investigations, both in vitro and in vivo, are necessary in order to better understand the role of the variants identified in the pathogenesis of obesity.


Author(s):  
Wusheng Xiao ◽  
William M Oldham ◽  
Carnen Priolo ◽  
Arvind K Pandey ◽  
Joseph Loscalzo

Rationale: Specific mechanisms linking inflammation and metabolic re-programming, two hallmarks of many pathobiological processes, remain incompletely defined. Objective: To delineate the integrative regulatory actions governing inflammation and metabolism in endothelial cells (ECs). Methods and Results: Metabolomic profiling, glucose labeling and tracing, and Seahorse extracellular flux analyses revealed that the inflammatory mediators, tumor necrosis factor α (TNFα) and lipopolysaccharide (LPS), extensively reprogram cellular metabolism, and particularly enhance glycolysis, mitochondrial oxidative phosphorylation (OXPHOS), and the pentose phosphate pathway (PPP) in primary human arterial ECs. Mechanistically, the enhancement in glycolysis and PPP is mediated by activation of the nuclear factor-κB (NF-κB)-6-phosphofructo-2-kinase/fructose 2,6-bisphosphatase 3 (PFKFB3) axis and upregulation of glucose 6-phosphate dehydrogenase (G6PD), respectively; while enhanced OXPHOS was attributed to suppression of the forkhead box O1 (FOXO1)-pyruvate dehydrogenase kinase 4 (PDK4) axis. Restoration of the FOXO1-PDK4 axis attenuated the TNFα- or LPS-induced increase in OXPHOS but worsened inflammation in vitro, whereas enhancement of OXPHOS by pharmacological blockade of PDKs attenuated inflammation in mesenteric vessels of LPS-treated mice. Notably, suppression of G6PD expression or its activity potentiated the metabolic shift to glycolysis and/or endothelial inflammation, while inhibition of the NF-κB-PFKFB3 signaling, conversely, blunted the increased glycolysis and/or inflammation in in vitro and in vivo sepsis models. Conclusions: These results indicate that inflammatory mediators modulate the metabolic fates of glucose, and that stimulation of glycolysis promotes inflammation, whereas enhancement of OXPHOS and the PPP suppresses inflammation in the endothelium. Characterization of these immunometabolic phenotypes may have implications for the pathogenesis and treatment of many cardiovascular diseases.


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