H₂S-mediated blockage of protein acetylation and oxidative stress attenuates lipid overload-induced cardiac senescence

Hydrogen sulphide (H2S), a newly identified gasotransmitter, can be endogenously produced by cystathionine gamma-lyase (CSE) in the cardiovascular system. This study investigated the role of the CSE/H2S system on lipid overload-induced lipotoxicity and cardiac senescence. Lipid overload in rat cardiomyocyte cells (H9C2) promoted intracellular accumulation of lipid, oxidative stress, mitochondrial dysfunctions, lipid peroxidation and inhibited cell viability, all of which could be reversed by exogenously applied H2S. Further data revealed that H2S protected H9C2 cells from lipid overload-induced senescence by altering the expressions of lipid metabolism-related genes and inhibiting cellular acetyl-CoA and global protein acetylation. Enhancement of protein acetylation abolished the protective role of H2S on cardiac senescence. In vivo, knockout of the CSE gene strengthened cardiac lipid accumulation, protein acetylation, and cellular ageing in high fat diet-fed mice. Taken together, the CSE/H2S system is capable of maintaining lipid homeostasis and cellular senescence in heart cells under lipid overload.</p

<i>glpX</i> gene deletion does not completely abolish the FBPase activity in <i>Δglpx</i>: FBPase Activity was measured in nmol/min/mg protein in crude extracts, mean of two determinations, limit of detection = 0.4.

<p>All values are with a substrate-free control (no FBP) subtracted. The reported readings are the average of 6 measurements coming from duplicate protein samples (n = 3X2 = 6).</p

In vitro growth profile of <i>ΔglpX</i>, WT <i>Mtb</i> and <i>glpX</i> complement on combination of carbon sources.

<p>Growth profile in 7H9 medium and a) 0.1% each of glycerol and acetate, b) 0.1% each of dextrose and acetate, and c) 0.1% each of dextrose and glycerol. Growth profiles are representative of a triplicate data set.</p

MICs for standard antibacterial drugs as determined by the MABA assay.

<p>^a Reported MIC values are an average (± standard deviation) of 6 independent assays. Although the MIC of PA-824 for the <i>ΔglpX</i> strain is significantly higher (about 3–4 fold) than that observed for WT <i>Mtb</i> strain, it is within the normal MIC range of 0.015 to 0.5 μM.</p><p>MICs for standard antibacterial drugs as determined by the MABA assay.</p

In vitro growth profile of <i>ΔglpX</i>, WT <i>Mtb</i> and <i>glpX</i> complement in a) 7H9 medium + OADC enrichment, b) 7H9 medium with no additional carbon source.

<p>Growth profiles are representative of a triplicate data set.</p

<i>glpX</i> is essential for growth in acute phase and survival during the chronic phase of <i>Mtb</i> infection in mice.

<p>Invivo growth and survival plot for <i>ΔglpX</i> compared to WT <i>Mtb</i> and the <i>glpX</i> complement. Data represents the mean±s.d. of six mice per time point.</p

List of primers used for the generation of Δ<i>glpx</i>.

<p>List of primers used for the generation of Δ<i>glpx</i>.</p

<i>glpx</i> Gene in <i>Mycobacterium tuberculosis - Fig 1 </i> Is Required for In Vitro Gluconeogenic Growth and In Vivo Survival

<p>Colony PCR and Southern Blot confirming the deletion of <i>glpX</i> gene a) Colony PCR results of the potential double cross overs (DCOs): Lane 1: 1kb ladder, Lane 2: PCR amplification product of suicidal delivery vector FM152 is about 2kb, Lane 3: PCR product of one such potential DCO (Colony 11) is 2kb, Lane 4: PCR product of a WT Mtb is about 3kb, b) Southern blot: Lane 1: WT genomic DNA digest with BamH1 which gives a fragment of about 610 bp (lowermost band in lane 1 and 3), Lane 2: Genomic DNA digest of a potential DCO (Colony 3) with the 610 bp fragment missing, Lane 3: Same as Lane 1, Lane 4: Genomic DNA digest of a potential DCO (Colony 11) with the 600 bp fragment missing.</p

In vitro growth profile of <i>ΔglpX</i>, WT <i>Mtb</i> and <i>glpX</i> complement on defined (or individual) carbon source(s).

<p>Growth profile in 7H9 medium a) 0.2% glycerol, b) 0.2% Acetate, and c) 0.2% dextrose. Growth profiles are representative of a triplicate data set.</p

In vitro growth profile of <i>ΔglpX</i>, WT <i>Mtb</i> and <i>glpX</i> complement on gluconeogenic carbon source(s).

<p>Growth profile in 7H9 medium a) 0.1% oleic acid, and b) 0.1% valeric acid Growth profiles are representative of a triplicate data set.</p