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TMPyP4, a Stabilizer of Nucleic Acid Secondary Structure, Is a Novel Acetylcholinesterase Inhibitor.

Fujiwara N, Mazzola M, Cai E, Wang M, Cave JW - PLoS ONE (2015)

Bottom Line: Intraperitoneal administration of low TMPyP4 doses (10mg/kg), similar to those used for photosensitization, did not significantly reduce Th transcript levels in several catecholaminergic regions.Administration of a high dose (40 mg/kg), similar to those used for tumor xenograph reduction, unexpectedly induced flaccid paralysis in an age and sex-dependent manner.Age-dependent differences in HO-2 expression levels may account for some of the variable in vivo effects of high TMPyP4 doses.

View Article: PubMed Central - PubMed

Affiliation: Burke Medical Research Institute, White Plains, New York, United States of America.

ABSTRACT
The porphyrin compound, TMPyP4 (5,10,15,20-Tetrakis-(N-methyl-4-pyridyl)porphine), is widely used as a photosensitizer and a modulator of nucleic acid secondary structure stability. Our group recently showed in cultured cells and forebrain slice cultures that this compound can also down regulate expression of Tyrosine hydroxylase (Th), which encodes the rate-limiting enzyme in catecholamine biosynthesis, by stabilizing DNA secondary structures in the Th proximal promoter. The current study sought to establish whether treatment with TMPyP4 could modify mouse Th expression levels in vivo. Intraperitoneal administration of low TMPyP4 doses (10mg/kg), similar to those used for photosensitization, did not significantly reduce Th transcript levels in several catecholaminergic regions. Administration of a high dose (40 mg/kg), similar to those used for tumor xenograph reduction, unexpectedly induced flaccid paralysis in an age and sex-dependent manner. In vitro analyses revealed that TMPyP4, but not putative metabolites, inhibited Acetylcholinesterase activity and pre-treatment of TMPyP4 with Hemeoxygenase-2 (HO-2) rescued Acetylcholinesterase function. Age-dependent differences in HO-2 expression levels may account for some of the variable in vivo effects of high TMPyP4 doses. Together, these studies indicate that only low doses of TMPyP4, such as those typically used for photosensitization, are well tolerated in vivo. Thus, despite its widespread use in vitro, TMPyP4 is not ideal for modifying neuronal gene expression in vivo by manipulating nucleic acid secondary structure stability, which highlights the need to identify more clinically suitable compounds that can modulate nucleic acid secondary structure and gene expression.

No MeSH data available.


Related in: MedlinePlus

In vitro vs. in vivo modulation of Th expression by TMPyP4.A, transcription assays with SH-SY5Y cells transfected with a reporter under the control of the rat 4.5kb Th promoter that are also treated with either saline, TMPyP2 or TMPyP4. Mean relative promoter activities are shown with error bars representing the standard deviation. ** indicates p<0.001, * indicates p = 0.02 and n.s. indicates not significant. B, Th transcript levels, as measured by quantitative RT-PCR, in the adrenal glands, olfactory bulb and midbrain of adult mice administered either saline, TMPyP2 or TMPyP4 (n = 8 for both male and female). Mean relative transcript levels are shown with error bars representing the standard error of the mean. ** indicates p<0.01, * indicates p = 0.03 and n.s. indicates not significant.
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pone.0139167.g002: In vitro vs. in vivo modulation of Th expression by TMPyP4.A, transcription assays with SH-SY5Y cells transfected with a reporter under the control of the rat 4.5kb Th promoter that are also treated with either saline, TMPyP2 or TMPyP4. Mean relative promoter activities are shown with error bars representing the standard deviation. ** indicates p<0.001, * indicates p = 0.02 and n.s. indicates not significant. B, Th transcript levels, as measured by quantitative RT-PCR, in the adrenal glands, olfactory bulb and midbrain of adult mice administered either saline, TMPyP2 or TMPyP4 (n = 8 for both male and female). Mean relative transcript levels are shown with error bars representing the standard error of the mean. ** indicates p<0.01, * indicates p = 0.03 and n.s. indicates not significant.

Mentions: We previously showed that the Th promoter can form G-quadruplex and i-motif secondary structures and assays with forebrain organotypic slice cultures indicated that stabilization of these secondary structures with TMPyP4 reduces Th promoter activity [5]. Transcription assays with SH-SY5Y cells transfected with a reporter containing the 4.5kb rat Th promoter and treated with either TMPyP2 or TMPyP4 confirmed that TMPyP4 can selectively repress Th promoter activity (Fig 2A).


TMPyP4, a Stabilizer of Nucleic Acid Secondary Structure, Is a Novel Acetylcholinesterase Inhibitor.

Fujiwara N, Mazzola M, Cai E, Wang M, Cave JW - PLoS ONE (2015)

In vitro vs. in vivo modulation of Th expression by TMPyP4.A, transcription assays with SH-SY5Y cells transfected with a reporter under the control of the rat 4.5kb Th promoter that are also treated with either saline, TMPyP2 or TMPyP4. Mean relative promoter activities are shown with error bars representing the standard deviation. ** indicates p<0.001, * indicates p = 0.02 and n.s. indicates not significant. B, Th transcript levels, as measured by quantitative RT-PCR, in the adrenal glands, olfactory bulb and midbrain of adult mice administered either saline, TMPyP2 or TMPyP4 (n = 8 for both male and female). Mean relative transcript levels are shown with error bars representing the standard error of the mean. ** indicates p<0.01, * indicates p = 0.03 and n.s. indicates not significant.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4581631&req=5

pone.0139167.g002: In vitro vs. in vivo modulation of Th expression by TMPyP4.A, transcription assays with SH-SY5Y cells transfected with a reporter under the control of the rat 4.5kb Th promoter that are also treated with either saline, TMPyP2 or TMPyP4. Mean relative promoter activities are shown with error bars representing the standard deviation. ** indicates p<0.001, * indicates p = 0.02 and n.s. indicates not significant. B, Th transcript levels, as measured by quantitative RT-PCR, in the adrenal glands, olfactory bulb and midbrain of adult mice administered either saline, TMPyP2 or TMPyP4 (n = 8 for both male and female). Mean relative transcript levels are shown with error bars representing the standard error of the mean. ** indicates p<0.01, * indicates p = 0.03 and n.s. indicates not significant.
Mentions: We previously showed that the Th promoter can form G-quadruplex and i-motif secondary structures and assays with forebrain organotypic slice cultures indicated that stabilization of these secondary structures with TMPyP4 reduces Th promoter activity [5]. Transcription assays with SH-SY5Y cells transfected with a reporter containing the 4.5kb rat Th promoter and treated with either TMPyP2 or TMPyP4 confirmed that TMPyP4 can selectively repress Th promoter activity (Fig 2A).

Bottom Line: Intraperitoneal administration of low TMPyP4 doses (10mg/kg), similar to those used for photosensitization, did not significantly reduce Th transcript levels in several catecholaminergic regions.Administration of a high dose (40 mg/kg), similar to those used for tumor xenograph reduction, unexpectedly induced flaccid paralysis in an age and sex-dependent manner.Age-dependent differences in HO-2 expression levels may account for some of the variable in vivo effects of high TMPyP4 doses.

View Article: PubMed Central - PubMed

Affiliation: Burke Medical Research Institute, White Plains, New York, United States of America.

ABSTRACT
The porphyrin compound, TMPyP4 (5,10,15,20-Tetrakis-(N-methyl-4-pyridyl)porphine), is widely used as a photosensitizer and a modulator of nucleic acid secondary structure stability. Our group recently showed in cultured cells and forebrain slice cultures that this compound can also down regulate expression of Tyrosine hydroxylase (Th), which encodes the rate-limiting enzyme in catecholamine biosynthesis, by stabilizing DNA secondary structures in the Th proximal promoter. The current study sought to establish whether treatment with TMPyP4 could modify mouse Th expression levels in vivo. Intraperitoneal administration of low TMPyP4 doses (10mg/kg), similar to those used for photosensitization, did not significantly reduce Th transcript levels in several catecholaminergic regions. Administration of a high dose (40 mg/kg), similar to those used for tumor xenograph reduction, unexpectedly induced flaccid paralysis in an age and sex-dependent manner. In vitro analyses revealed that TMPyP4, but not putative metabolites, inhibited Acetylcholinesterase activity and pre-treatment of TMPyP4 with Hemeoxygenase-2 (HO-2) rescued Acetylcholinesterase function. Age-dependent differences in HO-2 expression levels may account for some of the variable in vivo effects of high TMPyP4 doses. Together, these studies indicate that only low doses of TMPyP4, such as those typically used for photosensitization, are well tolerated in vivo. Thus, despite its widespread use in vitro, TMPyP4 is not ideal for modifying neuronal gene expression in vivo by manipulating nucleic acid secondary structure stability, which highlights the need to identify more clinically suitable compounds that can modulate nucleic acid secondary structure and gene expression.

No MeSH data available.


Related in: MedlinePlus