The Experts below are selected from a list of 186 Experts worldwide ranked by ideXlab platform
Karen T Graf - One of the best experts on this subject based on the ideXlab platform.
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tornadic shear stress induces a transient calcineurin dependent hypervirulent phenotype in mucorales molds
Mbio, 2020Co-Authors: Sebastian Wurster, Ashraf S. Ibrahim, Nathaniel D. Albert, Amol C Shetty, Alexander M Tatara, Joseph Heitman, Soo Chan Lee, Carrie Mccracken, Karen T GrafAbstract:Trauma-related necrotizing myocutaneous mucormycosis (NMM) has a high morbidity and mortality in victims of combat-related injuries, geometeorological disasters, and severe burns. Inspired by the observation that several recent clusters of NMM have been associated with extreme mechanical forces (e.g., during tornados), we studied the impact of mechanical stress on Mucoralean biology and virulence in a Drosophila melanogaster infection model. In contrast to other experimental procedures to exert mechanical stress, tornadic shear challenge (TSC) by magnetic stirring induced a hypervirulent phenotype in several clinically relevant Mucorales species but not in Aspergillus or Fusarium Whereas fungal growth rates, morphogenesis, and susceptibility to noxious environments or phagocytes were not altered by TSC, soluble factors released in the supernatant of shear-challenged R. arrhizus spores rendered static spores hypervirulent. Consistent with a rapid decay of TSC-induced hypervirulence, minimal transcriptional changes were revealed by comparative RNA sequencing analysis of static and shear-challenged Rhizopus arrhizus However, inhibition of the calcineurin/heat shock protein 90 (hsp90) stress response circuitry by cyclosporine and Tanespimycin abrogated the increased pathogenicity of R. arrhizus spores following TSC. Similarly, calcineurin loss-of-function mutants of Mucor circinelloides displayed no increased virulence capacity in flies after undergoing TSC. Collectively, these results establish that TSC induces hypervirulence specifically in Mucorales and point out the calcineurin/hsp90 pathway as a key orchestrator of this phenotype. Our findings invite future studies of topical calcineurin inhibitor treatment of wounds as an adjunct mitigation strategy for NMM following high-energy trauma.IMPORTANCE Given the limited efficacy of current medical treatments in trauma-related necrotizing mucormycosis, there is a dire need to better understand the Mucoralean pathophysiology in order to develop novel strategies to counteract fungal tissue invasion following severe trauma. Here, we describe that tornadic shear stress challenge transiently induces a hypervirulent phenotype in various pathogenic Mucorales species but not in other molds known to cause wound infections. Pharmacological and genetic inhibition of calcineurin signaling abrogated hypervirulence in shear stress-challenged Mucorales, encouraging further evaluation of (topical) calcineurin inhibitors to improve therapeutic outcomes of NMM after combat-related blast injuries or violent storms.
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tornadic shear stress induces a transient calcineurin dependent hyper virulent phenotype in mucorales molds
bioRxiv, 2020Co-Authors: Sebastian Wurster, Ashraf S. Ibrahim, Nathaniel D. Albert, Amol C Shetty, Alexander M Tatara, Joseph Heitman, Soo Chan Lee, Carrie Mccracken, Karen T GrafAbstract:Trauma-related necrotizing myocutaneous mucormycosis (NMM) has a high morbidity and mortality in victims of combat-related injuries, geo-meteorological disasters, and severe burns. Inspired by the observation that several recent clusters of NMM have been associated with extreme mechanical forces (e.g. during tornados), we studied the impact of mechanical stress on Mucoralean biology and virulence in a Drosophila melanogaster infection model. In contrast to other experimental procedures to exert mechanical stress, tornadic shear challenge (TSC) by magnetic stirring induced a hyper-virulent phenotype in several clinically relevant Mucorales species but not in Aspergillus or Fusarium. Whereas fungal growth rates, morphogenesis, and susceptibility to noxious environments or phagocytes were not altered by TSC, soluble factors released in the supernatant of shear-challenged R. arrhizus spores rendered static spores hyper-virulent. Consistent with a rapid decay of TSC-induced hyper-virulence, minimal transcriptional changes were revealed by comparative RNA sequencing analysis of static and shear-challenged Rhizopus arrhizus. However, inhibition of the calcineurin/heat shock protein 90 (hsp90) stress response circuitry by cyclosporine A (CsA) and Tanespimycin abrogated the increased pathogenicity of R. arrhizus spores following TSC. Similarly, calcineurin loss-of-function mutants of Mucor circinelloides displayed no increased virulence capacity in flies after undergoing TSC. Collectively, these results establish that TSC induces hyper-virulence specifically in Mucorales and point out the calcineurin/hsp90 pathway as a key orchestra-tor of this phenotype. Our findings invite future studies of topical calcineurin inhibitor treatment of wounds as an adjunct mitigation strategy for NMM following high-energy trauma.
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tornadic shear stress induces a transient calcineurin dependent hyper virulent phenotype in mucorales molds
bioRxiv, 2020Co-Authors: Sebastian Wurster, Ashraf S. Ibrahim, Nathaniel D. Albert, Amol C Shetty, Alexander M Tatara, Joseph Heitman, Soo Chan Lee, Carrie Mccracken, Karen T GrafAbstract:Abstract Trauma-related necrotizing myocutaneous mucormycosis (NMM) has a high morbidity and mortality in victims of combat-related injuries, geo-meteorological disasters, and severe burns. Inspired by the observation that several recent clusters of NMM have been associated with extreme mechanical forces (e.g. during tornados), we studied the impact of mechanical stress on Mucoralean biology and virulence in a Drosophila melanogaster infection model. In contrast to other experimental procedures to exert mechanical stress, tornadic shear challenge (TSC) by magnetic stirring induced a hyper-virulent phenotype in several clinically relevant Mucorales species but not in Aspergillus or Fusarium. Whereas fungal growth rates, morphogenesis, and susceptibility to noxious environments or phagocytes were not altered by TSC, soluble factors released in the supernatant of shear-challenged R. arrhizus spores rendered static spores hyper-virulent. Consistent with a rapid decay of TSC-induced hyper-virulence, minimal transcriptional changes were revealed by comparative RNA sequencing analysis of static and shear-challenged Rhizopus arrhizus. However, inhibition of the calcineurin/heat shock protein 90 (hsp90) stress response circuitry by cyclosporine A (CsA) and Tanespimycin abrogated the increased pathogenicity of R. arrhizus spores following TSC. Similarly, calcineurin loss-of-function mutants of Mucor circinelloides displayed no increased virulence capacity in flies after undergoing TSC. Collectively, these results establish that TSC induces hyper-virulence specifically in Mucorales and point out the calcineurin/hsp90 pathway as a key orchestrator of this phenotype. Our findings invite future studies of topical calcineurin inhibitor treatment of wounds as an adjunct mitigation strategy for NMM following high-energy trauma. Significance Given the limited efficacy of current medical treatments in trauma-related necrotizing mucormycosis, there is a dire need to better understand the Mucoralean pathophysiology in order to develop novel strategies to counteract fungal tissue invasion following severe trauma. Here, we describe that tornadic shear stress challenge transiently induces a hyper-virulent phenotype in various pathogenic Mucorales species but not in other molds known to cause wound infections. Our data support a model whereby shear stress-induced hyper-virulence is primarily driven by soluble factors and orchestrated by the calcineurin/hsp90 pathway. Importantly, pharmacological and genetic inhibition of calcineurin signaling abrogated hyper-virulence in shear stress-challenged Mucorales, encouraging further evaluation of (topical) calcineurin inhibitors to improve therapeutic outcomes of NMM after combat-related blast injuries or violent storms.
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Tornadic Shear Stress Induces a Transient, Calcineurin-Dependent Hypervirulent Phenotype in Mucorales Molds
'American Society for Microbiology', 2020Co-Authors: Sebastian Wurster, Ashraf S. Ibrahim, Nathaniel D. Albert, Amol C Shetty, Alexander M Tatara, Joseph Heitman, Soo Chan Lee, Carrie Mccracken, Karen T Graf, Antonios G. MikosAbstract:Given the limited efficacy of current medical treatments in trauma-related necrotizing mucormycosis, there is a dire need to better understand the Mucoralean pathophysiology in order to develop novel strategies to counteract fungal tissue invasion following severe trauma. Here, we describe that tornadic shear stress challenge transiently induces a hypervirulent phenotype in various pathogenic Mucorales species but not in other molds known to cause wound infections. Pharmacological and genetic inhibition of calcineurin signaling abrogated hypervirulence in shear stress-challenged Mucorales, encouraging further evaluation of (topical) calcineurin inhibitors to improve therapeutic outcomes of NMM after combat-related blast injuries or violent storms.Trauma-related necrotizing myocutaneous mucormycosis (NMM) has a high morbidity and mortality in victims of combat-related injuries, geometeorological disasters, and severe burns. Inspired by the observation that several recent clusters of NMM have been associated with extreme mechanical forces (e.g., during tornados), we studied the impact of mechanical stress on Mucoralean biology and virulence in a Drosophila melanogaster infection model. In contrast to other experimental procedures to exert mechanical stress, tornadic shear challenge (TSC) by magnetic stirring induced a hypervirulent phenotype in several clinically relevant Mucorales species but not in Aspergillus or Fusarium. Whereas fungal growth rates, morphogenesis, and susceptibility to noxious environments or phagocytes were not altered by TSC, soluble factors released in the supernatant of shear-challenged R. arrhizus spores rendered static spores hypervirulent. Consistent with a rapid decay of TSC-induced hypervirulence, minimal transcriptional changes were revealed by comparative RNA sequencing analysis of static and shear-challenged Rhizopus arrhizus. However, inhibition of the calcineurin/heat shock protein 90 (hsp90) stress response circuitry by cyclosporine and Tanespimycin abrogated the increased pathogenicity of R. arrhizus spores following TSC. Similarly, calcineurin loss-of-function mutants of Mucor circinelloides displayed no increased virulence capacity in flies after undergoing TSC. Collectively, these results establish that TSC induces hypervirulence specifically in Mucorales and point out the calcineurin/hsp90 pathway as a key orchestrator of this phenotype. Our findings invite future studies of topical calcineurin inhibitor treatment of wounds as an adjunct mitigation strategy for NMM following high-energy trauma
Ashraf S. Ibrahim - One of the best experts on this subject based on the ideXlab platform.
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tornadic shear stress induces a transient calcineurin dependent hypervirulent phenotype in mucorales molds
Mbio, 2020Co-Authors: Sebastian Wurster, Ashraf S. Ibrahim, Nathaniel D. Albert, Amol C Shetty, Alexander M Tatara, Joseph Heitman, Soo Chan Lee, Carrie Mccracken, Karen T GrafAbstract:Trauma-related necrotizing myocutaneous mucormycosis (NMM) has a high morbidity and mortality in victims of combat-related injuries, geometeorological disasters, and severe burns. Inspired by the observation that several recent clusters of NMM have been associated with extreme mechanical forces (e.g., during tornados), we studied the impact of mechanical stress on Mucoralean biology and virulence in a Drosophila melanogaster infection model. In contrast to other experimental procedures to exert mechanical stress, tornadic shear challenge (TSC) by magnetic stirring induced a hypervirulent phenotype in several clinically relevant Mucorales species but not in Aspergillus or Fusarium Whereas fungal growth rates, morphogenesis, and susceptibility to noxious environments or phagocytes were not altered by TSC, soluble factors released in the supernatant of shear-challenged R. arrhizus spores rendered static spores hypervirulent. Consistent with a rapid decay of TSC-induced hypervirulence, minimal transcriptional changes were revealed by comparative RNA sequencing analysis of static and shear-challenged Rhizopus arrhizus However, inhibition of the calcineurin/heat shock protein 90 (hsp90) stress response circuitry by cyclosporine and Tanespimycin abrogated the increased pathogenicity of R. arrhizus spores following TSC. Similarly, calcineurin loss-of-function mutants of Mucor circinelloides displayed no increased virulence capacity in flies after undergoing TSC. Collectively, these results establish that TSC induces hypervirulence specifically in Mucorales and point out the calcineurin/hsp90 pathway as a key orchestrator of this phenotype. Our findings invite future studies of topical calcineurin inhibitor treatment of wounds as an adjunct mitigation strategy for NMM following high-energy trauma.IMPORTANCE Given the limited efficacy of current medical treatments in trauma-related necrotizing mucormycosis, there is a dire need to better understand the Mucoralean pathophysiology in order to develop novel strategies to counteract fungal tissue invasion following severe trauma. Here, we describe that tornadic shear stress challenge transiently induces a hypervirulent phenotype in various pathogenic Mucorales species but not in other molds known to cause wound infections. Pharmacological and genetic inhibition of calcineurin signaling abrogated hypervirulence in shear stress-challenged Mucorales, encouraging further evaluation of (topical) calcineurin inhibitors to improve therapeutic outcomes of NMM after combat-related blast injuries or violent storms.
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tornadic shear stress induces a transient calcineurin dependent hyper virulent phenotype in mucorales molds
bioRxiv, 2020Co-Authors: Sebastian Wurster, Ashraf S. Ibrahim, Nathaniel D. Albert, Amol C Shetty, Alexander M Tatara, Joseph Heitman, Soo Chan Lee, Carrie Mccracken, Karen T GrafAbstract:Trauma-related necrotizing myocutaneous mucormycosis (NMM) has a high morbidity and mortality in victims of combat-related injuries, geo-meteorological disasters, and severe burns. Inspired by the observation that several recent clusters of NMM have been associated with extreme mechanical forces (e.g. during tornados), we studied the impact of mechanical stress on Mucoralean biology and virulence in a Drosophila melanogaster infection model. In contrast to other experimental procedures to exert mechanical stress, tornadic shear challenge (TSC) by magnetic stirring induced a hyper-virulent phenotype in several clinically relevant Mucorales species but not in Aspergillus or Fusarium. Whereas fungal growth rates, morphogenesis, and susceptibility to noxious environments or phagocytes were not altered by TSC, soluble factors released in the supernatant of shear-challenged R. arrhizus spores rendered static spores hyper-virulent. Consistent with a rapid decay of TSC-induced hyper-virulence, minimal transcriptional changes were revealed by comparative RNA sequencing analysis of static and shear-challenged Rhizopus arrhizus. However, inhibition of the calcineurin/heat shock protein 90 (hsp90) stress response circuitry by cyclosporine A (CsA) and Tanespimycin abrogated the increased pathogenicity of R. arrhizus spores following TSC. Similarly, calcineurin loss-of-function mutants of Mucor circinelloides displayed no increased virulence capacity in flies after undergoing TSC. Collectively, these results establish that TSC induces hyper-virulence specifically in Mucorales and point out the calcineurin/hsp90 pathway as a key orchestra-tor of this phenotype. Our findings invite future studies of topical calcineurin inhibitor treatment of wounds as an adjunct mitigation strategy for NMM following high-energy trauma.
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tornadic shear stress induces a transient calcineurin dependent hyper virulent phenotype in mucorales molds
bioRxiv, 2020Co-Authors: Sebastian Wurster, Ashraf S. Ibrahim, Nathaniel D. Albert, Amol C Shetty, Alexander M Tatara, Joseph Heitman, Soo Chan Lee, Carrie Mccracken, Karen T GrafAbstract:Abstract Trauma-related necrotizing myocutaneous mucormycosis (NMM) has a high morbidity and mortality in victims of combat-related injuries, geo-meteorological disasters, and severe burns. Inspired by the observation that several recent clusters of NMM have been associated with extreme mechanical forces (e.g. during tornados), we studied the impact of mechanical stress on Mucoralean biology and virulence in a Drosophila melanogaster infection model. In contrast to other experimental procedures to exert mechanical stress, tornadic shear challenge (TSC) by magnetic stirring induced a hyper-virulent phenotype in several clinically relevant Mucorales species but not in Aspergillus or Fusarium. Whereas fungal growth rates, morphogenesis, and susceptibility to noxious environments or phagocytes were not altered by TSC, soluble factors released in the supernatant of shear-challenged R. arrhizus spores rendered static spores hyper-virulent. Consistent with a rapid decay of TSC-induced hyper-virulence, minimal transcriptional changes were revealed by comparative RNA sequencing analysis of static and shear-challenged Rhizopus arrhizus. However, inhibition of the calcineurin/heat shock protein 90 (hsp90) stress response circuitry by cyclosporine A (CsA) and Tanespimycin abrogated the increased pathogenicity of R. arrhizus spores following TSC. Similarly, calcineurin loss-of-function mutants of Mucor circinelloides displayed no increased virulence capacity in flies after undergoing TSC. Collectively, these results establish that TSC induces hyper-virulence specifically in Mucorales and point out the calcineurin/hsp90 pathway as a key orchestrator of this phenotype. Our findings invite future studies of topical calcineurin inhibitor treatment of wounds as an adjunct mitigation strategy for NMM following high-energy trauma. Significance Given the limited efficacy of current medical treatments in trauma-related necrotizing mucormycosis, there is a dire need to better understand the Mucoralean pathophysiology in order to develop novel strategies to counteract fungal tissue invasion following severe trauma. Here, we describe that tornadic shear stress challenge transiently induces a hyper-virulent phenotype in various pathogenic Mucorales species but not in other molds known to cause wound infections. Our data support a model whereby shear stress-induced hyper-virulence is primarily driven by soluble factors and orchestrated by the calcineurin/hsp90 pathway. Importantly, pharmacological and genetic inhibition of calcineurin signaling abrogated hyper-virulence in shear stress-challenged Mucorales, encouraging further evaluation of (topical) calcineurin inhibitors to improve therapeutic outcomes of NMM after combat-related blast injuries or violent storms.
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Tornadic Shear Stress Induces a Transient, Calcineurin-Dependent Hypervirulent Phenotype in Mucorales Molds
'American Society for Microbiology', 2020Co-Authors: Sebastian Wurster, Ashraf S. Ibrahim, Nathaniel D. Albert, Amol C Shetty, Alexander M Tatara, Joseph Heitman, Soo Chan Lee, Carrie Mccracken, Karen T Graf, Antonios G. MikosAbstract:Given the limited efficacy of current medical treatments in trauma-related necrotizing mucormycosis, there is a dire need to better understand the Mucoralean pathophysiology in order to develop novel strategies to counteract fungal tissue invasion following severe trauma. Here, we describe that tornadic shear stress challenge transiently induces a hypervirulent phenotype in various pathogenic Mucorales species but not in other molds known to cause wound infections. Pharmacological and genetic inhibition of calcineurin signaling abrogated hypervirulence in shear stress-challenged Mucorales, encouraging further evaluation of (topical) calcineurin inhibitors to improve therapeutic outcomes of NMM after combat-related blast injuries or violent storms.Trauma-related necrotizing myocutaneous mucormycosis (NMM) has a high morbidity and mortality in victims of combat-related injuries, geometeorological disasters, and severe burns. Inspired by the observation that several recent clusters of NMM have been associated with extreme mechanical forces (e.g., during tornados), we studied the impact of mechanical stress on Mucoralean biology and virulence in a Drosophila melanogaster infection model. In contrast to other experimental procedures to exert mechanical stress, tornadic shear challenge (TSC) by magnetic stirring induced a hypervirulent phenotype in several clinically relevant Mucorales species but not in Aspergillus or Fusarium. Whereas fungal growth rates, morphogenesis, and susceptibility to noxious environments or phagocytes were not altered by TSC, soluble factors released in the supernatant of shear-challenged R. arrhizus spores rendered static spores hypervirulent. Consistent with a rapid decay of TSC-induced hypervirulence, minimal transcriptional changes were revealed by comparative RNA sequencing analysis of static and shear-challenged Rhizopus arrhizus. However, inhibition of the calcineurin/heat shock protein 90 (hsp90) stress response circuitry by cyclosporine and Tanespimycin abrogated the increased pathogenicity of R. arrhizus spores following TSC. Similarly, calcineurin loss-of-function mutants of Mucor circinelloides displayed no increased virulence capacity in flies after undergoing TSC. Collectively, these results establish that TSC induces hypervirulence specifically in Mucorales and point out the calcineurin/hsp90 pathway as a key orchestrator of this phenotype. Our findings invite future studies of topical calcineurin inhibitor treatment of wounds as an adjunct mitigation strategy for NMM following high-energy trauma
Sebastian Wurster - One of the best experts on this subject based on the ideXlab platform.
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tornadic shear stress induces a transient calcineurin dependent hypervirulent phenotype in mucorales molds
Mbio, 2020Co-Authors: Sebastian Wurster, Ashraf S. Ibrahim, Nathaniel D. Albert, Amol C Shetty, Alexander M Tatara, Joseph Heitman, Soo Chan Lee, Carrie Mccracken, Karen T GrafAbstract:Trauma-related necrotizing myocutaneous mucormycosis (NMM) has a high morbidity and mortality in victims of combat-related injuries, geometeorological disasters, and severe burns. Inspired by the observation that several recent clusters of NMM have been associated with extreme mechanical forces (e.g., during tornados), we studied the impact of mechanical stress on Mucoralean biology and virulence in a Drosophila melanogaster infection model. In contrast to other experimental procedures to exert mechanical stress, tornadic shear challenge (TSC) by magnetic stirring induced a hypervirulent phenotype in several clinically relevant Mucorales species but not in Aspergillus or Fusarium Whereas fungal growth rates, morphogenesis, and susceptibility to noxious environments or phagocytes were not altered by TSC, soluble factors released in the supernatant of shear-challenged R. arrhizus spores rendered static spores hypervirulent. Consistent with a rapid decay of TSC-induced hypervirulence, minimal transcriptional changes were revealed by comparative RNA sequencing analysis of static and shear-challenged Rhizopus arrhizus However, inhibition of the calcineurin/heat shock protein 90 (hsp90) stress response circuitry by cyclosporine and Tanespimycin abrogated the increased pathogenicity of R. arrhizus spores following TSC. Similarly, calcineurin loss-of-function mutants of Mucor circinelloides displayed no increased virulence capacity in flies after undergoing TSC. Collectively, these results establish that TSC induces hypervirulence specifically in Mucorales and point out the calcineurin/hsp90 pathway as a key orchestrator of this phenotype. Our findings invite future studies of topical calcineurin inhibitor treatment of wounds as an adjunct mitigation strategy for NMM following high-energy trauma.IMPORTANCE Given the limited efficacy of current medical treatments in trauma-related necrotizing mucormycosis, there is a dire need to better understand the Mucoralean pathophysiology in order to develop novel strategies to counteract fungal tissue invasion following severe trauma. Here, we describe that tornadic shear stress challenge transiently induces a hypervirulent phenotype in various pathogenic Mucorales species but not in other molds known to cause wound infections. Pharmacological and genetic inhibition of calcineurin signaling abrogated hypervirulence in shear stress-challenged Mucorales, encouraging further evaluation of (topical) calcineurin inhibitors to improve therapeutic outcomes of NMM after combat-related blast injuries or violent storms.
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tornadic shear stress induces a transient calcineurin dependent hyper virulent phenotype in mucorales molds
bioRxiv, 2020Co-Authors: Sebastian Wurster, Ashraf S. Ibrahim, Nathaniel D. Albert, Amol C Shetty, Alexander M Tatara, Joseph Heitman, Soo Chan Lee, Carrie Mccracken, Karen T GrafAbstract:Trauma-related necrotizing myocutaneous mucormycosis (NMM) has a high morbidity and mortality in victims of combat-related injuries, geo-meteorological disasters, and severe burns. Inspired by the observation that several recent clusters of NMM have been associated with extreme mechanical forces (e.g. during tornados), we studied the impact of mechanical stress on Mucoralean biology and virulence in a Drosophila melanogaster infection model. In contrast to other experimental procedures to exert mechanical stress, tornadic shear challenge (TSC) by magnetic stirring induced a hyper-virulent phenotype in several clinically relevant Mucorales species but not in Aspergillus or Fusarium. Whereas fungal growth rates, morphogenesis, and susceptibility to noxious environments or phagocytes were not altered by TSC, soluble factors released in the supernatant of shear-challenged R. arrhizus spores rendered static spores hyper-virulent. Consistent with a rapid decay of TSC-induced hyper-virulence, minimal transcriptional changes were revealed by comparative RNA sequencing analysis of static and shear-challenged Rhizopus arrhizus. However, inhibition of the calcineurin/heat shock protein 90 (hsp90) stress response circuitry by cyclosporine A (CsA) and Tanespimycin abrogated the increased pathogenicity of R. arrhizus spores following TSC. Similarly, calcineurin loss-of-function mutants of Mucor circinelloides displayed no increased virulence capacity in flies after undergoing TSC. Collectively, these results establish that TSC induces hyper-virulence specifically in Mucorales and point out the calcineurin/hsp90 pathway as a key orchestra-tor of this phenotype. Our findings invite future studies of topical calcineurin inhibitor treatment of wounds as an adjunct mitigation strategy for NMM following high-energy trauma.
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tornadic shear stress induces a transient calcineurin dependent hyper virulent phenotype in mucorales molds
bioRxiv, 2020Co-Authors: Sebastian Wurster, Ashraf S. Ibrahim, Nathaniel D. Albert, Amol C Shetty, Alexander M Tatara, Joseph Heitman, Soo Chan Lee, Carrie Mccracken, Karen T GrafAbstract:Abstract Trauma-related necrotizing myocutaneous mucormycosis (NMM) has a high morbidity and mortality in victims of combat-related injuries, geo-meteorological disasters, and severe burns. Inspired by the observation that several recent clusters of NMM have been associated with extreme mechanical forces (e.g. during tornados), we studied the impact of mechanical stress on Mucoralean biology and virulence in a Drosophila melanogaster infection model. In contrast to other experimental procedures to exert mechanical stress, tornadic shear challenge (TSC) by magnetic stirring induced a hyper-virulent phenotype in several clinically relevant Mucorales species but not in Aspergillus or Fusarium. Whereas fungal growth rates, morphogenesis, and susceptibility to noxious environments or phagocytes were not altered by TSC, soluble factors released in the supernatant of shear-challenged R. arrhizus spores rendered static spores hyper-virulent. Consistent with a rapid decay of TSC-induced hyper-virulence, minimal transcriptional changes were revealed by comparative RNA sequencing analysis of static and shear-challenged Rhizopus arrhizus. However, inhibition of the calcineurin/heat shock protein 90 (hsp90) stress response circuitry by cyclosporine A (CsA) and Tanespimycin abrogated the increased pathogenicity of R. arrhizus spores following TSC. Similarly, calcineurin loss-of-function mutants of Mucor circinelloides displayed no increased virulence capacity in flies after undergoing TSC. Collectively, these results establish that TSC induces hyper-virulence specifically in Mucorales and point out the calcineurin/hsp90 pathway as a key orchestrator of this phenotype. Our findings invite future studies of topical calcineurin inhibitor treatment of wounds as an adjunct mitigation strategy for NMM following high-energy trauma. Significance Given the limited efficacy of current medical treatments in trauma-related necrotizing mucormycosis, there is a dire need to better understand the Mucoralean pathophysiology in order to develop novel strategies to counteract fungal tissue invasion following severe trauma. Here, we describe that tornadic shear stress challenge transiently induces a hyper-virulent phenotype in various pathogenic Mucorales species but not in other molds known to cause wound infections. Our data support a model whereby shear stress-induced hyper-virulence is primarily driven by soluble factors and orchestrated by the calcineurin/hsp90 pathway. Importantly, pharmacological and genetic inhibition of calcineurin signaling abrogated hyper-virulence in shear stress-challenged Mucorales, encouraging further evaluation of (topical) calcineurin inhibitors to improve therapeutic outcomes of NMM after combat-related blast injuries or violent storms.
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Tornadic Shear Stress Induces a Transient, Calcineurin-Dependent Hypervirulent Phenotype in Mucorales Molds
'American Society for Microbiology', 2020Co-Authors: Sebastian Wurster, Ashraf S. Ibrahim, Nathaniel D. Albert, Amol C Shetty, Alexander M Tatara, Joseph Heitman, Soo Chan Lee, Carrie Mccracken, Karen T Graf, Antonios G. MikosAbstract:Given the limited efficacy of current medical treatments in trauma-related necrotizing mucormycosis, there is a dire need to better understand the Mucoralean pathophysiology in order to develop novel strategies to counteract fungal tissue invasion following severe trauma. Here, we describe that tornadic shear stress challenge transiently induces a hypervirulent phenotype in various pathogenic Mucorales species but not in other molds known to cause wound infections. Pharmacological and genetic inhibition of calcineurin signaling abrogated hypervirulence in shear stress-challenged Mucorales, encouraging further evaluation of (topical) calcineurin inhibitors to improve therapeutic outcomes of NMM after combat-related blast injuries or violent storms.Trauma-related necrotizing myocutaneous mucormycosis (NMM) has a high morbidity and mortality in victims of combat-related injuries, geometeorological disasters, and severe burns. Inspired by the observation that several recent clusters of NMM have been associated with extreme mechanical forces (e.g., during tornados), we studied the impact of mechanical stress on Mucoralean biology and virulence in a Drosophila melanogaster infection model. In contrast to other experimental procedures to exert mechanical stress, tornadic shear challenge (TSC) by magnetic stirring induced a hypervirulent phenotype in several clinically relevant Mucorales species but not in Aspergillus or Fusarium. Whereas fungal growth rates, morphogenesis, and susceptibility to noxious environments or phagocytes were not altered by TSC, soluble factors released in the supernatant of shear-challenged R. arrhizus spores rendered static spores hypervirulent. Consistent with a rapid decay of TSC-induced hypervirulence, minimal transcriptional changes were revealed by comparative RNA sequencing analysis of static and shear-challenged Rhizopus arrhizus. However, inhibition of the calcineurin/heat shock protein 90 (hsp90) stress response circuitry by cyclosporine and Tanespimycin abrogated the increased pathogenicity of R. arrhizus spores following TSC. Similarly, calcineurin loss-of-function mutants of Mucor circinelloides displayed no increased virulence capacity in flies after undergoing TSC. Collectively, these results establish that TSC induces hypervirulence specifically in Mucorales and point out the calcineurin/hsp90 pathway as a key orchestrator of this phenotype. Our findings invite future studies of topical calcineurin inhibitor treatment of wounds as an adjunct mitigation strategy for NMM following high-energy trauma
Steven Sugarman - One of the best experts on this subject based on the ideXlab platform.
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p1 17 08 a phase ii trial of ganetespib efficacy and safety in patients pts with metastatic breast cancer mbc
Cancer Research, 2011Co-Authors: Komal Jhaveri, Sarat Chandarlapaty, Gabriella Dandrea, D Lake, Theresa Gilewski, Pamela Drullinsky, Steven Sugarman, C Wasserheitleiblich, M E Moynahan, Sofia HaqueAbstract:Background: Heat shock protein 90 (Hsp90) is a molecular chaperone that maintains the stability of a number of key cellular oncoproteins (client proteins). When Hsp90 is inhibited, its client proteins undergo ubiquitination and degradation. HER2 is one of the most sensitive client proteins of Hsp90 and we have previously shown that Tanespimycin, a geldanamycin-based Hsp90 inhibitor, is active in trastuzumab-refractory HER2+ MBC, with a RR of 22% and clinical benefit rate of 59%. Ganetespib is a synthetic, small molecule, IV administered, non-geldanamycin Hsp90 inhibitor which has broader inhibitory effects on oncoproteins with pre-clinical antitumor activity in more breast cancer (BC) subtypes, including triple negative breast cancer (TNBC). We therefore tested ganetespib in an unselected cohort of patients with advanced BC. Methods: Pts with locally advanced or MBC were treated with single agent ganetespib at 200mg/m2 once weekly for 3 weeks, on a 28 day cycle. The primary endpoint of the trial was overall response rate using RECIST 1.1. Pts with HER2+ BC were required to have received prior therapy with trastuzumab. No more than 3 lines of chemotherapy in the metastatic setting were permitted and there was no limit on prior lines of hormone therapy. Pts were evaluated for response after 2 cycles. The trial used a Simon two-stage design requiring at least 3 responses among the first 22 pts, to allow expansion to a total of 40 pts. Results: A total of 14 pts have been treated thus far with a median age of 45.3 years (36.6 to 59.1) and the following subtypes: 8 ER+/HER2+, 3 ER-/HER2+, 1 ER+/HER2− and 2 TNBC. Pts received a median of 1.84 cycles (0.33 to 4). The most common treatment-related AEs were Grade 1/2 and included the following: diarrhea (64%), fatigue (50%), nausea (35%), vomiting (14%), insomnia (14%) and hypersensitivity reactions (35%). The diarrhea had an early onset ( Conclusions: These data show activity for single agent ganetespib in different subtypes of breast cancer. Ganetespib was well tolerated, with expected gastrointestinal toxicity that was mild in nature and manageable in all patients. Accrual continues and we will present updated data at the meeting. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-17-08.
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hsp90 inhibition is effective in breast cancer a phase ii trial of Tanespimycin 17 aag plus trastuzumab in patients with her2 positive metastatic breast cancer progressing on trastuzumab
Clinical Cancer Research, 2011Co-Authors: Shanu Modi, Sarat Chandarlapaty, Gabriella Dandrea, M E Moynahan, Alison Stopeck, David B Solit, Neal Rosen, Hannah M Linden, Maura N Dickler, Steven SugarmanAbstract:Purpose: HSP90 is a chaperone protein required for the stability of a variety of client proteins. 17-Demethoxygeldanamycin (17-AAG) is a natural product that binds to HSP90 and inhibits its activity, thereby inducing the degradation of these clients. In preclinical studies, HER2 is one of the most sensitive known client proteins of 17-AAG. On the basis of these data and activity in a phase I study, we conducted a phase II study of 17-AAG (Tanespimycin) with trastuzumab in advanced trastuzumab-refractory HER2-positive breast cancer. Experimental Design: We enrolled patients with metastatic HER2 + breast cancer whose disease had previously progressed on trastuzumab. All patients received weekly treatment with Tanespimycin at 450 mg/m 2 intravenously and trastuzumab at a conventional dose. Therapy was continued until disease progression. The primary endpoint was response rate by Response Evaluation Criteria in Solid Tumors (RECIST) criteria. Results: Thirty-one patients were enrolled with a median age of 53 years and a median Karnofsky performance status (KPS) of 90%. The most common toxicities, largely grade 1, were diarrhea, fatigue, nausea, and headache. The overall response rate was 22%, the clinical benefit rate [complete response + partial response + stable disease] was 59%, the median progression-free survival was 6 months (95% CI: 4–9), and the median overall survival was 17 months (95% CI: 16–28). Conclusions: This is the first phase II study to definitively show RECIST-defined responses for 17-AAG in solid tumors. Tanespimycin plus trastuzumab has significant anticancer activity in patients with HER2-positive, metastatic breast cancer previously progressing on trastuzumab. Further research exploring this therapeutic interaction and the activity of HSP90 inhibitors is clearly warranted. Clin Cancer Res; 17(15); 5132–9. ©2011 AACR .
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hsp90 molecular chaperone inhibitors are we there yet
Clinical Cancer Research, 2012Co-Authors: Len Neckers, Paul WorkmanAbstract:Heat shock protein (Hsp) 90 is an ATP-dependent molecular chaperone exploited by malignant cells to support activated oncoproteins, including many cancer-associated kinases and transcription factors, and is essential for oncogenic transformation. Originally viewed with skepticism, Hsp90 inhibitors are now actively pursued by the pharmaceutical industry, with 17 agents having entered clinical trials. Hsp90’s druggability was established using the natural products geldanamycin and radicicol which mimic the unusual ATP structure adopted in the chaperone’s N-terminal nucleotide-binding pocket and cause potent and selective blockade of ATP binding/hydrolysis, inhibit chaperone function, deplete oncogenic clients, and demonstrate antitumor activity. Preclinical data with these natural products have heightened interest in Hsp90 as a drug target, and 17-allylamino-17-demethoxygeldanamycin (17-AAG, Tanespimycin) has demonstrated clinical activity (as defined by RECIST criteria) in HER2+ breast cancer. Many optimized synthetic small molecule Hsp90 inhibitors from diverse chemotypes are now in clinical trials. We review the discovery and development of Hsp90 inhibitors and assess their future potential. There has been significant learning from experience in both the basic biology and the translational drug development around Hsp90, enhanced by the use of Hsp90 inhibitors as chemical probes. Success will likely lie in treating cancers addicted to particular driver oncogene products, such as HER2, ALK, EGFR and BRAF, that are sensitive Hsp90 clients, as well as in malignancies, especially multiple myeloma, where buffering of proteotoxic stress is critical for survival. We discuss approaches to enhancing the effectiveness of Hsp90 inhibitors and highlight new chaperone and stress response pathway targets, including HSF1 and Hsp70.
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abstract bsf2 1 molecular chaperones cancer dependence and druggability
Cancer Research, 2010Co-Authors: Paul WorkmanAbstract:Cancer cells live in a stressed state caused by genomic abnormalities, deregulated biochemical pathways and microenvironmental pressures. As a result they evolve, during malignant transformation and progression, a dependency on a range of molecular chaperone systems that provide essential protein folding, oncoprotein activation and anti-apoptotic functions. This chaperone dependence creates a specific vulnerability in cancer cells that is now being actively exploited in drug discovery. Our own work has focused on using a combination of genetic techniques and chemical probes (a powerful combination, see Workman P, Collins I. Probing the probes: fitness factors for small molecule tools. Chem Biol 17 561-577 2010) to enhance our understanding of the cancer biology of molecular chaperone systems. At the same time we are heavily involved in the discovery and clinical evaluation of drugs that act on these cancer-supportive molecular machines. The trail has been blazed by HSP90 inhibitors, of which at least 13 are now in clinical development. Signs of clinical activity have been seen, most notably with 17-AAG (Tanespimycin) in trastuzumab-refractory, ERRB2-positive breast cancer. The new HSP90 inhibitor NVP-AUY922, which we discovered with Vernalis and is being developed by Novartis, shows good activity in breast tumour models (Eccles SA et al NVP-AUY922: a novel heat shock protein 90 inhibitor active against xenograft tumour growth, angiogenesis, and metastasis. Cancer Res 68 2850-2860 2008). The activity of HSP90 inhibitors is self-limited by the mechanism-based activation of the protective, HSF1-dependent heat shock response. This presentation will provide an update on the discovery, development and use of HSP90 inhibitors and will describe emerging data on the identification and validation of new potential chaperone system targets, including AHA1, CDC37 and the HSP70 family (eg Powers MV, Clarke PA, Workman P. Dual targeting of HSC70 and HSP72 inhibits HSP90 function and induces tumour-specific apoptosis. Cancer Cell 14 250-262 2008). Molecular chaperones are overexpressed in clinical breast cancers, and in many examples their expression correlates with clinical outcome. Moreover, many oncoproteins important in breast cancer are client proteins for HSP90, including ER, PR, ERBB2, AKT/PKB/and CRAF. Thus HSP90 and other chaperone inhibitors have particular potential in breast cancer. Progress towards, and future challenges for, the potential of anti-chaperone drugs to become part of the personalized cancer medicine of the future (Yap TA, Sandhu SK, Workman P, de Bono JS. Envisioning the future of early anticancer drug development. Nat Rev Cancer 10 514-523 2010) will be highlighted. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr BSF2-1.