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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

Age and gender analysis of HO-1/2 expression levels in liver and skeletal muscle.A-B, western blots for HO-1/2 and GAPDH in the liver and skeletal muscle, respectively, of young and old adult mice for both sexes. C and E, D and F, average relative western blot band intensities for HO-1/2 in liver and skeletal muscle tissue, respectively. Averages are from 3 independent trials for each age and gender in both liver and muscle tissue.
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pone.0139167.g004: Age and gender analysis of HO-1/2 expression levels in liver and skeletal muscle.A-B, western blots for HO-1/2 and GAPDH in the liver and skeletal muscle, respectively, of young and old adult mice for both sexes. C and E, D and F, average relative western blot band intensities for HO-1/2 in liver and skeletal muscle tissue, respectively. Averages are from 3 independent trials for each age and gender in both liver and muscle tissue.

Mentions: To determine whether age- or gender-based differences in the expression levels of either HO-1 or HO-2 could contribute the differential responses to TMPyP4, we quantified HO-1 and HO-2 protein levels from Western blots of liver and skeletal muscle lysates from both young and old adult mice. These studies found no differences in HO-1 protein levels in either liver or skeletal muscle tissue (Fig 4A–4D). By contrast, HO-2 protein levels in both the liver and skeletal muscle showed a trend as being greater in the young adult mice as compared to the older mice (Fig 4E–4H). This trend did not reach a level of significance (p>0.05), but the results suggest that there may be subtle differences in HO-2 expression levels between older and younger adults that may, in part, underlie the differential response to TMPyP4.


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)

Age and gender analysis of HO-1/2 expression levels in liver and skeletal muscle.A-B, western blots for HO-1/2 and GAPDH in the liver and skeletal muscle, respectively, of young and old adult mice for both sexes. C and E, D and F, average relative western blot band intensities for HO-1/2 in liver and skeletal muscle tissue, respectively. Averages are from 3 independent trials for each age and gender in both liver and muscle tissue.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0139167.g004: Age and gender analysis of HO-1/2 expression levels in liver and skeletal muscle.A-B, western blots for HO-1/2 and GAPDH in the liver and skeletal muscle, respectively, of young and old adult mice for both sexes. C and E, D and F, average relative western blot band intensities for HO-1/2 in liver and skeletal muscle tissue, respectively. Averages are from 3 independent trials for each age and gender in both liver and muscle tissue.
Mentions: To determine whether age- or gender-based differences in the expression levels of either HO-1 or HO-2 could contribute the differential responses to TMPyP4, we quantified HO-1 and HO-2 protein levels from Western blots of liver and skeletal muscle lysates from both young and old adult mice. These studies found no differences in HO-1 protein levels in either liver or skeletal muscle tissue (Fig 4A–4D). By contrast, HO-2 protein levels in both the liver and skeletal muscle showed a trend as being greater in the young adult mice as compared to the older mice (Fig 4E–4H). This trend did not reach a level of significance (p>0.05), but the results suggest that there may be subtle differences in HO-2 expression levels between older and younger adults that may, in part, underlie the differential response to TMPyP4.

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