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CO-Releasing Molecules Have Nonheme Targets in Bacteria: Transcriptomic, Mathematical Modeling and Biochemical Analyses of CORM-3 [Ru(CO)3Cl(glycinate)] Actions on a Heme-Deficient Mutant of Escherichia coli.

Wilson JL, Wareham LK, McLean S, Begg R, Greaves S, Mann BE, Sanguinetti G, Poole RK - Antioxid. Redox Signal. (2015)

Bottom Line: Carbon monoxide-releasing molecules (CORMs) are being developed with the ultimate goal of safely utilizing the therapeutic potential of CO clinically, including applications in antimicrobial therapy.A full understanding of the actions of CORMs is vital to understand their toxic effects.This is a vital step in exploiting the potential, already demonstrated, for using optimized CORMs in antimicrobial therapy.

View Article: PubMed Central - PubMed

Affiliation: 1 Department of Molecular Biology and Biotechnology, The University of Sheffield , Sheffield, United Kingdom .

ABSTRACT

Aims: Carbon monoxide-releasing molecules (CORMs) are being developed with the ultimate goal of safely utilizing the therapeutic potential of CO clinically, including applications in antimicrobial therapy. Hemes are generally considered the prime targets of CO and CORMs, so we tested this hypothesis using heme-deficient bacteria, applying cellular, transcriptomic, and biochemical tools.

Results: CORM-3 [Ru(CO)3Cl(glycinate)] readily penetrated Escherichia coli hemA bacteria and was inhibitory to these and Lactococcus lactis, even though they lack all detectable hemes. Transcriptomic analyses, coupled with mathematical modeling of transcription factor activities, revealed that the response to CORM-3 in hemA bacteria is multifaceted but characterized by markedly elevated expression of iron acquisition and utilization mechanisms, global stress responses, and zinc management processes. Cell membranes are disturbed by CORM-3.

Innovation: This work has demonstrated for the first time that CORM-3 (and to a lesser extent its inactivated counterpart) has multiple cellular targets other than hemes. A full understanding of the actions of CORMs is vital to understand their toxic effects.

Conclusion: This work has furthered our understanding of the key targets of CORM-3 in bacteria and raises the possibility that the widely reported antimicrobial effects cannot be attributed to classical biochemical targets of CO. This is a vital step in exploiting the potential, already demonstrated, for using optimized CORMs in antimicrobial therapy.

No MeSH data available.


Related in: MedlinePlus

CORM-3 treatment depletes iron levels in wild-type and heme-deficientE. colicells over time. Intracellular iron levels in hemA (closed circles) and wild-type (open circles) cells were measured by ICP-AES over a time-course of 120 min after exposure of cultures to 100 μM CORM-3. Data are plotted as means±SEM from ≥3 biological replicates.
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f5: CORM-3 treatment depletes iron levels in wild-type and heme-deficientE. colicells over time. Intracellular iron levels in hemA (closed circles) and wild-type (open circles) cells were measured by ICP-AES over a time-course of 120 min after exposure of cultures to 100 μM CORM-3. Data are plotted as means±SEM from ≥3 biological replicates.

Mentions: Since transcript levels for genes involved in iron homeostasis were altered, suggesting a shortage of biologically available iron induced by CORM-3 stress, we measured intracellular iron levels in wild-type and hemA cells under the same conditions used for microarray experiments. The level of iron was higher in the heme-deficient mutant at all time-points; however, after CORM-3 addition, iron levels dropped by ∼50% in both cultures over 120 min (Fig. 5). A hemA mutant of Salmonella enterica also showed marginally higher free iron levels than the wild-type strain (20).


CO-Releasing Molecules Have Nonheme Targets in Bacteria: Transcriptomic, Mathematical Modeling and Biochemical Analyses of CORM-3 [Ru(CO)3Cl(glycinate)] Actions on a Heme-Deficient Mutant of Escherichia coli.

Wilson JL, Wareham LK, McLean S, Begg R, Greaves S, Mann BE, Sanguinetti G, Poole RK - Antioxid. Redox Signal. (2015)

CORM-3 treatment depletes iron levels in wild-type and heme-deficientE. colicells over time. Intracellular iron levels in hemA (closed circles) and wild-type (open circles) cells were measured by ICP-AES over a time-course of 120 min after exposure of cultures to 100 μM CORM-3. Data are plotted as means±SEM from ≥3 biological replicates.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4492677&req=5

f5: CORM-3 treatment depletes iron levels in wild-type and heme-deficientE. colicells over time. Intracellular iron levels in hemA (closed circles) and wild-type (open circles) cells were measured by ICP-AES over a time-course of 120 min after exposure of cultures to 100 μM CORM-3. Data are plotted as means±SEM from ≥3 biological replicates.
Mentions: Since transcript levels for genes involved in iron homeostasis were altered, suggesting a shortage of biologically available iron induced by CORM-3 stress, we measured intracellular iron levels in wild-type and hemA cells under the same conditions used for microarray experiments. The level of iron was higher in the heme-deficient mutant at all time-points; however, after CORM-3 addition, iron levels dropped by ∼50% in both cultures over 120 min (Fig. 5). A hemA mutant of Salmonella enterica also showed marginally higher free iron levels than the wild-type strain (20).

Bottom Line: Carbon monoxide-releasing molecules (CORMs) are being developed with the ultimate goal of safely utilizing the therapeutic potential of CO clinically, including applications in antimicrobial therapy.A full understanding of the actions of CORMs is vital to understand their toxic effects.This is a vital step in exploiting the potential, already demonstrated, for using optimized CORMs in antimicrobial therapy.

View Article: PubMed Central - PubMed

Affiliation: 1 Department of Molecular Biology and Biotechnology, The University of Sheffield , Sheffield, United Kingdom .

ABSTRACT

Aims: Carbon monoxide-releasing molecules (CORMs) are being developed with the ultimate goal of safely utilizing the therapeutic potential of CO clinically, including applications in antimicrobial therapy. Hemes are generally considered the prime targets of CO and CORMs, so we tested this hypothesis using heme-deficient bacteria, applying cellular, transcriptomic, and biochemical tools.

Results: CORM-3 [Ru(CO)3Cl(glycinate)] readily penetrated Escherichia coli hemA bacteria and was inhibitory to these and Lactococcus lactis, even though they lack all detectable hemes. Transcriptomic analyses, coupled with mathematical modeling of transcription factor activities, revealed that the response to CORM-3 in hemA bacteria is multifaceted but characterized by markedly elevated expression of iron acquisition and utilization mechanisms, global stress responses, and zinc management processes. Cell membranes are disturbed by CORM-3.

Innovation: This work has demonstrated for the first time that CORM-3 (and to a lesser extent its inactivated counterpart) has multiple cellular targets other than hemes. A full understanding of the actions of CORMs is vital to understand their toxic effects.

Conclusion: This work has furthered our understanding of the key targets of CORM-3 in bacteria and raises the possibility that the widely reported antimicrobial effects cannot be attributed to classical biochemical targets of CO. This is a vital step in exploiting the potential, already demonstrated, for using optimized CORMs in antimicrobial therapy.

No MeSH data available.


Related in: MedlinePlus