scholarly journals Reductive Power Generated by Mycobacterium leprae Through Cholesterol Oxidation Contributes to Lipid and ATP Synthesis

2021 ◽  
Vol 11 ◽  
Author(s):  
Thabatta L. S. A. Rosa ◽  
Maria Angela M. Marques ◽  
Zachary DeBoard ◽  
Kelly Hutchins ◽  
Carlos Adriano A. Silva ◽  
...  
Keyword(s):  
Ldl Cholesterol ◽  
Cholesterol Oxidase ◽  
Close Association ◽  
Atp Synthesis ◽  
Mycobacterium Leprae ◽  
Cholesterol Oxidation ◽  
Bacterial Survival ◽  
Catabolic Pathway ◽  
Oxidation Activity ◽  
Microscopy Analysis

Upon infection, Mycobacterium leprae, an obligate intracellular bacillus, induces accumulation of cholesterol-enriched lipid droplets (LDs) in Schwann cells (SCs). LDs are promptly recruited to M. leprae-containing phagosomes, and inhibition of this process decreases bacterial survival, suggesting that LD recruitment constitutes a mechanism by which host-derived lipids are delivered to intracellular M. leprae. We previously demonstrated that M. leprae has preserved only the capacity to oxidize cholesterol to cholestenone, the first step of the normal cholesterol catabolic pathway. In this study we investigated the biochemical relevance of cholesterol oxidation on bacterial pathogenesis in SCs. Firstly, we showed that M. leprae increases the uptake of LDL-cholesterol by infected SCs. Moreover, fluorescence microscopy analysis revealed a close association between M. leprae and the internalized LDL-cholesterol within the host cell. By using Mycobacterium smegmatis mutant strains complemented with M. leprae genes, we demonstrated that ml1942 coding for 3β-hydroxysteroid dehydrogenase (3β-HSD), but not ml0389 originally annotated as cholesterol oxidase (ChoD), was responsible for the cholesterol oxidation activity detected in M. leprae. The 3β-HSD activity generates the electron donors NADH and NADPH that, respectively, fuel the M. leprae respiratory chain and provide reductive power for the biosynthesis of the dominant bacterial cell wall lipids phthiocerol dimycocerosate (PDIM) and phenolic glycolipid (PGL)-I. Inhibition of M. leprae 3β-HSD activity with the 17β-[N-(2,5-di-t-butylphenyl)carbamoyl]-6-azaandrost-4-en-3one (compound 1), decreased bacterial intracellular survival in SCs. In conclusion, our findings confirm the accumulation of cholesterol in infected SCs and its potential delivery to the intracellular bacterium. Furthermore, we provide strong evidence that cholesterol oxidation is an essential catabolic pathway for M. leprae pathogenicity and point to 3β-HSD as a prime drug target that may be used in combination with current multidrug regimens to shorten leprosy treatment and ameliorate nerve damage.

scholarly journals Corrigendum: Reductive Power Generated by Mycobacterium leprae Through Cholesterol Oxidation Contributes to Lipid and ATP Synthesis

2021 ◽  
Vol 11 ◽  
Author(s):  
Thabatta L. S. A. Rosa ◽  
Maria Angela M. Marques ◽  
Zachary DeBoard ◽  
Kelly Hutchins ◽  
Carlos Adriano A. Silva ◽  
...  
Keyword(s):  
Atp Synthesis ◽  
Mycobacterium Leprae ◽  
Cholesterol Oxidation

scholarly journals Structure-Guided Computational Approaches to Unravel Druggable Proteomic Landscape of Mycobacterium leprae

2021 ◽  
Vol 8 ◽  
Author(s):  
Sundeep Chaitanya Vedithi ◽  
Sony Malhotra ◽  
Marta Acebrón-García-de-Eulate ◽  
Modestas Matusevicius ◽  
Pedro Henrique Monteiro Torres ◽  
...  
Keyword(s):  
Drug Discovery ◽  
Schwann Cells ◽  
Protein Structures ◽  
Mycobacterium Leprae ◽  
Data Bank ◽  
Nerve Damage ◽  
Structural Proteomics ◽  
Bacterial Survival ◽  
Functional Sites

Leprosy, caused by Mycobacterium leprae (M. leprae), is treated with a multidrug regimen comprising Dapsone, Rifampicin, and Clofazimine. These drugs exhibit bacteriostatic, bactericidal and anti-inflammatory properties, respectively, and control the dissemination of infection in the host. However, the current treatment is not cost-effective, does not favor patient compliance due to its long duration (12 months) and does not protect against the incumbent nerve damage, which is a severe leprosy complication. The chronic infectious peripheral neuropathy associated with the disease is primarily due to the bacterial components infiltrating the Schwann cells that protect neuronal axons, thereby inducing a demyelinating phenotype. There is a need to discover novel/repurposed drugs that can act as short duration and effective alternatives to the existing treatment regimens, preventing nerve damage and consequent disability associated with the disease. Mycobacterium leprae is an obligate pathogen resulting in experimental intractability to cultivate the bacillus in vitro and limiting drug discovery efforts to repositioning screens in mouse footpad models. The dearth of knowledge related to structural proteomics of M. leprae, coupled with emerging antimicrobial resistance to all the three drugs in the multidrug therapy, poses a need for concerted novel drug discovery efforts. A comprehensive understanding of the proteomic landscape of M. leprae is indispensable to unravel druggable targets that are essential for bacterial survival and predilection of human neuronal Schwann cells. Of the 1,614 protein-coding genes in the genome of M. leprae, only 17 protein structures are available in the Protein Data Bank. In this review, we discussed efforts made to model the proteome of M. leprae using a suite of software for protein modeling that has been developed in the Blundell laboratory. Precise template selection by employing sequence-structure homology recognition software, multi-template modeling of the monomeric models and accurate quality assessment are the hallmarks of the modeling process. Tools that map interfaces and enable building of homo-oligomers are discussed in the context of interface stability. Other software is described to determine the druggable proteome by using information related to the chokepoint analysis of the metabolic pathways, gene essentiality, homology to human proteins, functional sites, druggable pockets and fragment hotspot maps.

Protective effect of fresh and processed Jalapeño and Serrano peppers against food lipid and human LDL cholesterol oxidation

2012 ◽  
Vol 133 (3) ◽  
pp. 827-834 ◽  
Author(s):  
Emilio Alvarez-Parrilla ◽  
Laura A. de la Rosa ◽  
Ryszard Amarowicz ◽  
Fereidoon Shahidi
Keyword(s):  
Protective Effect ◽  
Ldl Cholesterol ◽  
Cholesterol Oxidation

scholarly journals Steroid Metabolism in Thermophilic Actinobacterium Saccharopolyspora hirsuta VKM Ac-666T

2021 ◽  
Vol 9 (12) ◽  
pp. 2554
Author(s):  
Tatyana Lobastova ◽  
Victoria Fokina ◽  
Sergey Tarlachkov ◽  
Andrey Shutov ◽  
Eugeny Bragin ◽  
...  
Keyword(s):  
Thermophilic Bacteria ◽  
Cholesterol Oxidase ◽  
Cascade Reactions ◽  
Cholesterol Oxidation ◽  
P450 Monooxygenase ◽  
Thermophilic Microorganisms ◽  
Mycobacterium Tuberculosis H37rv ◽  
Rhodococcus Jostii Rha1 ◽  
Saccharopolyspora Hirsuta ◽  
Steroid Catabolism

The application of thermophilic microorganisms opens new prospects in steroid biotechnology, but little is known to date on steroid catabolism by thermophilic strains. The thermophilic strain Saccharopolyspora hirsuta VKM Ac-666T has been shown to convert various steroids and to fully degrade cholesterol. Cholest-4-en-3-one, cholesta-1,4-dien-3-one, 26-hydroxycholest-4-en-3-one, 3-oxo-cholest-4-en-26-oic acid, 3-oxo-cholesta-1,4-dien-26-oic acid, 26-hydroxycholesterol, 3β-hydroxy-cholest-5-en-26-oic acid were identified as intermediates in cholesterol oxidation. The structures were confirmed by 1H and 13C-NMR analyses. Aliphatic side chain hydroxylation at C26 and the A-ring modification at C3, which are putatively catalyzed by cytochrome P450 monooxygenase CYP125 and cholesterol oxidase, respectively, occur simultaneously in the strain and are followed by cascade reactions of aliphatic sidechain degradation and steroid core destruction via the known 9(10)-seco-pathway. The genes putatively related to the sterol and bile acid degradation pathways form three major clusters in the S. hirsuta genome. The sets of the genes include the orthologs of those involved in steroid catabolism in Mycobacterium tuberculosis H37Rv and Rhodococcus jostii RHA1 and related actinobacteria. Bioinformatics analysis of 52 publicly available genomes of thermophilic bacteria revealed only seven candidate strains that possess the key genes related to the 9(10)-seco pathway of steroid degradation, thus demonstrating that the ability to degrade steroids is not widespread among thermophilic bacteria.

scholarly journals Phenolic content, antioxidant and anti-inflammatory activities of seeds and leaves of date palm (Phoenix dactylifera L.)

2019 ◽  
Vol 5 ◽  
Author(s):  
Jenny A. John ◽  
Fereidoon Shahidi
Keyword(s):  
Date Palm ◽  
Ldl Cholesterol ◽  
Phenolic Content ◽  
Radical Scavenging ◽  
Phoenix Dactylifera ◽  
Cholesterol Oxidation ◽  
Total Phenolic ◽  
In Vitro Tests ◽  
Phoenix Dactylifera L ◽  
Anti Inflammatory

The total phenolic content of date palm (Phoenix dactylifera L.) seeds (samples 1 and 2) and leaves were determined and for the first time their antioxidant activity in a food system investigated. The anti-inflammatory activity and potency of samples in the inhibition of radical-induced DNA scission and human low-density lipoprotein (LDL) cholesterol oxidation was also evaluated. The total soluble phenolic content of the date palm leaves was 106.96 mg gallic acid equivalents (GAE)/g sample and ranged from 68.73 to 82.62 mg GAE/g of date seeds. Extracts showed good radical scavenging activity in the different in vitro tests conducted in this work and were found to be effective in inhibiting the oxidation of cooked ground meat. Soluble phenolic extract from date seeds of sample 1 was most effective in inhibiting DNA strand scission by 74.15%, while soluble phenolics from palm leaves showed the highest inhibition of LDL cholesterol oxidation (87.82%). Both samples significantly inhibited mRNA level of COX-2 at concentrations as low as 5 μg/mL, with the most potent inhibitory effect being for date palm leaf extracts at 50 μg/mL. A number of phenolic compounds including proanthocyanidin dimers, catechin, epicatechin, 5-O-caffeoylshikimic acid isomers, ferulic acid, rutin and isorhamnetin hexoside, among others, were detected in date palm seeds and leaves.

scholarly journals Mycobacterium leprae-induced Insulin-like Growth Factor I attenuates antimicrobial mechanisms, promoting bacterial survival in macrophages

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
L. R. Batista-Silva ◽  
Luciana Silva Rodrigues ◽  
Aislan de Carvalho Vivarini ◽  
Fabrício da Mota Ramalho Costa ◽  
Katherine Antunes de Mattos ◽  
...  
Keyword(s):  
Growth Factor ◽  
Mycobacterium Leprae ◽  
Insulin Like Growth Factor ◽  
Bacterial Survival ◽  
Factor I ◽  
Growth Factor I

scholarly journals Localization of cholesterol in sphingomyelinase-treated fibroblasts

1995 ◽  
Vol 308 (1) ◽  
pp. 269-274 ◽  
Author(s):  
M I Pörn ◽  
J P Slotte
Keyword(s):  
Plasma Membrane ◽  
Cell Surface ◽  
Staining Pattern ◽  
Cholesterol Oxidase ◽  
Cholesterol Oxidation ◽  
Cellular Cholesterol ◽  
Hypotonic Buffer ◽  
Induced Changes ◽  
Kinetics Of

The distribution of cellular unesterified cholesterol was studied in fibroblasts, which had been depleted of plasma membrane sphingomyelin by exposure to exogenous sphingomyelinase. This treatment has previously been shown to induce an increase in cholesterol esterification, a decrease in the biosynthesis of cholesterol, and a decreased susceptibility of cell cholesterol to oxidation with cholesterol oxidase. When the cellular localization of cholesterol was studied with fluorescent filipin staining, sphingomyelin depletion did not cause any visible changes in the filipin-cholesterol staining pattern, suggesting that the major part of cellular cholesterol was retained in the plasma membrane after sphingomyelinase treatment. After the oxidation of cell-surface cholesterol with cholesterol oxidase, the plasma membrane was no longer stained by filipin, but the plasma membrane cholesterol of sphingomyelin-depleted cells appeared to be resistant to oxidation with cholesterol oxidase when sphingomyelinase was used as an oxidation-promoting agent. However, the use of hypotonic buffer or phosphatidylcholine-specific phospholipase C together with cholesterol oxidase resulted in a complete oxidation of the cell-surface cholesterol in sphingomyelin-depleted cells, as evidenced by the filipin-cholesterol staining pattern. Similar results were obtained when [3H]cholesterol-labelled fibroblasts were used for determination of the susceptibility to cholesterol oxidation. The kinetics of [3H]cholesterol oxidation in sphingomyelin-depleted cells with cholesterol oxidase in hypotonic buffer indicated that approximately 85% of the cellular cholesterol still resided in the plasma membrane after sphingomyelin depletion. These results are contradictory to earlier reports on sphingomyelinase-induced changes in cellular cholesterol distribution and suggest that minor changes in the kinetics of cholesterol transport from the plasma membrane to the endoplasmic reticulum may be responsible for the sphingomyelinase-induced changes in the rates of cholesterol metabolism. Whereas the use of phospholipases to promote the oxidation of cholesterol in some instances might lead to misinterpretations, the use of hypotonic buffer together with cholesterol oxidase proved to be a more reliable method for the determination of cellular cholesterol distribution.

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