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Dermatology Online Journal Jul 2020Vitiligo is a depigmenting skin disorder that can cause significant patient distress. Treatment of vitiligo is challenging and should address patient's concern for...
Vitiligo is a depigmenting skin disorder that can cause significant patient distress. Treatment of vitiligo is challenging and should address patient's concern for cosmetic treatment. Herein, we report the case of a 60-year-old patient who achieved temporary improvement in pigmentation using a spray tan. Camouflaging vitiligo using a spray-tan is a reasonable, safe, and effective mechanism for management of vitiligo.
Topics: Administration, Cutaneous; Cosmetics; Dihydroxyacetone; Humans; Male; Middle Aged; Vitiligo
PubMed: 32898413
DOI: No ID Found -
Structure (London, England : 1993) Mar 2023Sulfoquinovose (SQ) is a key component of plant sulfolipids (sulfoquinovosyl diacylglycerols) and a major environmental reservoir of biological sulfur. Breakdown of SQ...
Sulfoquinovose (SQ) is a key component of plant sulfolipids (sulfoquinovosyl diacylglycerols) and a major environmental reservoir of biological sulfur. Breakdown of SQ is achieved by bacteria through the pathways of sulfoglycolysis. The sulfoglycolytic sulfofructose transaldolase (sulfo-SFT) pathway is used by gut-resident firmicutes and soil saprophytes. After isomerization of SQ to sulfofructose (SF), the namesake enzyme catalyzes the transaldol reaction of SF transferring dihydroxyacetone to 3C/4C acceptors to give sulfolactaldehyde and fructose-6-phosphate or sedoheptulose-7-phosphate. We report the 3D cryo-EM structure of SF transaldolase from Bacillus megaterium in apo and ligand bound forms, revealing a decameric structure formed from two pentameric rings of the protomer. We demonstrate a covalent "Schiff base" intermediate formed by reaction of SF with Lys89 within a conserved Asp-Lys-Glu catalytic triad and defined by an Arg-Trp-Arg sulfonate recognition triad. The structural characterization of the signature enzyme of the sulfo-SFT pathway provides key insights into molecular recognition of the sulfonate group of sulfosugars.
Topics: Transaldolase; Fructose-Bisphosphate Aldolase; Methylglucosides
PubMed: 36805128
DOI: 10.1016/j.str.2023.01.010 -
Effect of sugar metabolite methylglyoxal on equine lamellar explants: An ex vivo model of laminitis.PloS One 2021Laminitis is one of the most devastating diseases in equine medicine, and although several etiopathogenetic mechanisms have been proposed, few clear answers have been...
Laminitis is one of the most devastating diseases in equine medicine, and although several etiopathogenetic mechanisms have been proposed, few clear answers have been identified to date. Several lines of evidence point towards its underlying pathology as being metabolism-related. In the carbonyl stress pathway, sugars are converted to methylglyoxal (MG)-a highly reactive α-oxoaldehyde, mainly derived during glycolysis in eukaryotic cells from the triose phosphates: D-glyceraldehyde-3-phosphate and dihydroxyacetone phosphate. One common hypothesis is that MG could be synthesized during the digestive process in horses, and excessive levels absorbed into peripheral blood could be delivered to the foot and lead to alterations in the hoof lamellar structure. In the present study, employing an ex vivo experimental design, different concentrations of MG were applied to hoof explants (HE), which were then incubated and maintained in a specific medium for 24 and 48 h. Macroscopic and histological analyses and a separation force test were performed at 24 and 48 h post-MG application. Gene expression levels of matrix metalloproteinase (MMP)-2 and -14 and tissue inhibitor of metalloproteinase (TIMP)-2 were also measured at each time point for all experimental conditions. High concentrations of MG induced macroscopic and histological changes mimicking laminitis. The separation force test revealed that hoof tissue samples incubated for 24 h in a high concentration of MG, or with lower doses but for a longer period (48 h), demonstrated significant weaknesses, and samples were easily separated. All results support that high levels of MG could induce irreversible damage in HEs, mimicking laminitis in an ex vivo model.
Topics: Animals; Gene Expression; Hoof and Claw; Horses; Male; Matrix Metalloproteinase 14; Matrix Metalloproteinase 2; Models, Biological; Pyruvaldehyde; Sugars; Tissue Inhibitor of Metalloproteinase-2
PubMed: 34314429
DOI: 10.1371/journal.pone.0253840 -
Microbial Biotechnology Jul 2021Since methylotrophic yeasts such as Ogataea methanolica can use methanol as a sole carbon feedstock, they could be applied to produce valuable products from methanol, a...
Since methylotrophic yeasts such as Ogataea methanolica can use methanol as a sole carbon feedstock, they could be applied to produce valuable products from methanol, a next-generation energy source synthesized from natural gases, using genetic engineering tools. In this study, metabolite profiling of O. methanolica was conducted under glucose (Glc) and low and high methanol (L- and H-MeOH) conditions to show the adaptation mechanism to a H-MeOH environment. The yeast strain responded not only to the presence of methanol but also to its concentration based on the growth condition. Under H-MeOH conditions, O. methanolica downregulated the methanol utilization, glycolytic pathway and alcohol oxidase (AOD) isozymes and dihydroxyacetone synthase (DAS) expression compared with L-MeOH-grown cells. However, levels of energy carriers, such as ATP, were maintained to support cell survival. In H-MeOH-grown cells, reactive oxygen species (ROS) levels were significantly elevated. Along with increasing ROS levels, ROS scavenging system expression was significantly increased in H-MeOH-grown cells. Thus, we concluded that formaldehyde and H O , which are products of methanol oxidation by AOD isozymes in the peroxisome, are overproduced in H-MeOH-grown cells, and excessive ROS derived from these cells is generated in the cytosol, resulting in upregulation of the antioxidant system and downregulation of the methanol-utilizing pathway to suppress overproduction of toxic intermediates.
Topics: Gene Expression Regulation, Fungal; Methanol; Pichia; Saccharomycetales
PubMed: 33939325
DOI: 10.1111/1751-7915.13811 -
Signal Transduction and Targeted Therapy Nov 2020
Review
Topics: Animals; Dihydroxyacetone Phosphate; Glucose; Glycolysis; Humans; Mechanistic Target of Rapamycin Complex 1; Neoplasm Proteins; Neoplasms; Second Messenger Systems
PubMed: 33144567
DOI: 10.1038/s41392-020-00371-9 -
NPJ Science of Food Jul 2021This study examined the effects of oral administration of water extract of chlorella (WEC) (100 mg/kg bodyweight) and phenethylamine (10 μg/kg bodyweight) on...
This study examined the effects of oral administration of water extract of chlorella (WEC) (100 mg/kg bodyweight) and phenethylamine (10 μg/kg bodyweight) on high-fat diet (HFD)-induced liver damage in mice. Phenethylamine significantly mitigated HFD-induced lipid oxidation (generation of malondialdehyde) and liver damage without markedly decreasing hepatic lipid accumulation. WEC exerted similar effects although with decreased efficacy. In addition, WEC and phenethylamine decreased the methylglyoxal levels and increased the glyceraldehyde 3-phosphate dehydrogenase (GAPDH) protein levels in the liver. Methylglyoxal is generated from substrates of GAPDH, dihydroxyacetone phosphate and glyceraldehyde 3-phosphate. These facts indicate that methylglyoxal triggers oxidation of accumulated lipid, which generates malondialdehyde and consequently induces liver damage. Suppression of generation of toxic aldehydes by WEC and phenethylamine was also confirmed by maintaining hepatic cysteine, highly reactive to aldehydes. Thus, trace amounts of phenethylamine alleviate HFD-induced liver damage by regulating methylglyoxal via increase of GAPDH.
PubMed: 34301957
DOI: 10.1038/s41538-021-00105-3 -
Frontiers in Microbiology 2022Glycerol is a readily available and low-cost simple polyol compound, which can be used as a carbon source for microorganisms to produce various value-added products....
Glycerol is a readily available and low-cost simple polyol compound, which can be used as a carbon source for microorganisms to produce various value-added products. Understanding the underlying regulatory mechanism in glycerol metabolism is critical for making better use of glycerol for diverse applications. In a few reported strains, the glycerol utilization gene cluster ( operon) was shown to be regulated by the IclR family transcriptional regulator GylR. However, the molecular regulatory mechanism mediated by GylR has not been fully elucidated. In this study, we first analyzed the available genomes in the NCBI Genome database, and found that the operon-like gene clusters are conserved in and several other genera of . By taking NRRL 3585 as a model system, we identified that GylR represses the expressions of operon and by directly binding to their promoter regions. Both glycerol-3-phosphate and dihydroxyacetone phosphate can induce the dissociation of GylR from its binding sequences. Furthermore, we identified a minimal essential operator site (a palindromic 18-bp sequence) of GylR-like regulators in . Our study for the first time reported the binding sequences and effector molecules of GylR-like proteins in . The molecular regulatory mechanism mediated by GylR presumably exists widely in . Our findings would facilitate the design of glycerol utilization pathways for producing valuable products. Moreover, our study provided new basic elements for the development of glycerol-inducible regulatory tools for synthetic biology research in the future.
PubMed: 36504789
DOI: 10.3389/fmicb.2022.1078293 -
Bioresources and Bioprocessing Nov 20221,3-Dihydroxyacetone (DHA) is a commercially important chemical and widely used in cosmetics, pharmaceuticals, and food industries as it prevents excessive water...
1,3-Dihydroxyacetone (DHA) is a commercially important chemical and widely used in cosmetics, pharmaceuticals, and food industries as it prevents excessive water evaporation, and provides anti-ultraviolet radiation protection and antioxidant activity. Currently, the industrial production of DHA is based on a biotechnological synthetic route using Gluconobacter oxydans. However, achieving higher production requires more improvements in the synthetic process. In this study, we compared DHA synthesis levels in five industrial wild-type Gluconobacter strains, after which the G. oxydans WSH-003 strain was selected. Then, 16 dehydrogenase genes, unrelated to DHA synthesis, were individually knocked out, with one strain significantly enhancing DHA production, reaching 89.49 g L and 42.27% higher than the wild-type strain. By optimizing the culture media, including seed culture and fermentation media, DHA production was further enhanced. Finally, using an established fed-batch fermentation system, DHA production reached 198.81 g L in a 5 L bioreactor, with a glycerol conversion rate of 82.84%.
PubMed: 38647819
DOI: 10.1186/s40643-022-00610-7 -
Brazilian Journal of Microbiology :... 2016The principal objective of this study was to evaluate the kinetics of dihydroxyacetone production by Gluconobacter frateurii CGMCC 5397 under different oxygen volumetric...
The principal objective of this study was to evaluate the kinetics of dihydroxyacetone production by Gluconobacter frateurii CGMCC 5397 under different oxygen volumetric mass transfer coefficient (kLa) conditions in submerged bioreactors using biodiesel-derived crude glycerol as the carbon source. kLa is a key fermentation parameter for the production of dihydroxyacetone. Cultivations were conducted in baffled- and unbaffled-flask cultures (the kLa values were 24.32h(-1) and 52.05h(-1), respectively) and fed-batch cultures (the kLa values were held at 18.21h(-1), 46.03h(-1), and 82.14h(-1)) to achieve high dihydroxyacetone concentration and productivity. The results showed that a high kLa could dramatically increase dihydroxyacetone concentrations and productivities. The baffled-flask culture (with a kLa of 52.05h(-1)) favored glycerol utilization and dihydroxyacetone production, and a dihydroxyacetone concentration as high as 131.16g/L was achieved. When the kLa was set to 82.14h(-1) in the fed-batch culture, the dihydroxyacetone concentration, productivity and yield were 175.44g/L, 7.96g/L/h and 0.89g/g, respectively, all of which were significantly higher than those in previous studies and will benefit dihydroxyacetone industrial production.
Topics: Bioreactors; Biotransformation; Carbon; Dihydroxyacetone; Gluconobacter; Glycerol; Oxygen
PubMed: 26887235
DOI: 10.1016/j.bjm.2015.11.020 -
Theranostics 2023Despite growing evidence for mitochondria's involvement in cancer, the roles of specific metabolic components outside the respiratory complex have been little explored....
Despite growing evidence for mitochondria's involvement in cancer, the roles of specific metabolic components outside the respiratory complex have been little explored. We conducted metabolomic studies on mitochondrial DNA (mtDNA)-deficient (ρ0) cancer cells with lower proliferation rates to clarify the undefined roles of mitochondria in cancer growth. Despite extensive metabolic downregulation, ρ0 cells exhibited high glycerol-3-phosphate (G3P) level, due to low activity of mitochondrial glycerol-3-phosphate dehydrogenase (GPD2). Knockout (KO) of GPD2 resulted in cell growth suppression as well as inhibition of tumor progression Surprisingly, this was unrelated to the conventional bioenergetic function of GPD2. Instead, multi-omics results suggested major changes in ether lipid metabolism, for which GPD2 provides dihydroxyacetone phosphate (DHAP) in ether lipid biosynthesis. GPD2 KO cells exhibited significantly lower ether lipid level, and their slower growth was rescued by supplementation of a DHAP precursor or ether lipids. Mechanistically, ether lipid metabolism was associated with Akt pathway, and the downregulation of Akt/mTORC1 pathway due to GPD2 KO was rescued by DHAP supplementation. Overall, the GPD2-ether lipid-Akt axis is newly described for the control of cancer growth. DHAP supply, a non-bioenergetic process, may constitute an important role of mitochondria in cancer.
Topics: Energy Metabolism; Ethers; Glycerolphosphate Dehydrogenase; Mitochondria; Proto-Oncogene Proteins c-akt; Animals; Mice; Neoplasms; Humans
PubMed: 36632231
DOI: 10.7150/thno.75973