Re: TGF-beta1 in CFS impairs NRF2-ARE Phase II detox - supressing glutathione

[Guest guest]

I really didnt know what TGF-b did - how interesting that it inhibits phase II

detoxification! They have tested cytokine levels repeatedly in CFS and TGF-b is

the only one, as I remember, that time and time again comes up increased in CFS.

That certainly ties with increased oxidative stress and toxin build up in CFS.

Very interesting.

jasonlbreckenridge <jasonlbreckenridge@...> wrote: High levels of

TGF-beta1 are consistenly found in CFS. Neurophil

apoptosis study showed this was the net effect. Macrophaes probably

engulf and release the excess elastase.

NRF2 is pivotal for phase 2 detox and corrects protease/antiprotease

balance, including excess elastase.

http://www.lef.org/magazine/mag2005/sep2005_cover_dna_02.htm

Wasabi contains the most potent Phase II detox inducer for NRF2,

which is apparently a potent metabolite of broccoli's sulforaphane.

All 3 studies below support this.

---------------------------------------

Smad3-ATF3 signaling mediates TGF-beta suppression of genes encoding

Phase II detoxifying proteins.

Bakin AV, Stourman NV, Sekhar KR, Rinehart C, Yan X, Meredith MJ,

Arteaga CL, Freeman ML.

Department of Cancer Genetics, Roswell Park Cancer Institute,

Buffalo, NY 14263, USA. andrei.bakin@...

This study provides evidence that in mammary epithelial cells the

pluripotent cytokine TGF-beta1 repressed expression of multiple

genes involved in Phase II detoxification. GCLC, the gene that

encodes the catalytic subunit of the enzyme glutamate cysteine

ligase, the rate-limiting enzyme in the biosynthesis of glutathione,

was used as a molecular surrogate for investigating the mechanisms

by which TGF-beta suppressed Phase II gene expression. TGF-beta was

found to suppress luciferase reporter activity mediated by the human

GCLC proximal promoter, as well as reporter activity mediated by the

GCLC antioxidant response element, ARE4. TGF-beta downregulated

expression of endogenous GCLC mRNA and GCLC protein. TGF-beta

suppression of the Phase II genes correlated with a decrease in

cellular glutathione and an increase in cellular reactive oxygen

species. Ectopic expression of constitutively active Smad3E was

sufficient to inhibit both reporters in the absence of TGF-beta,

whereas dominant negative Smad3A blocked TGF-beta suppression.

Smad3E suppressed Nrf2-mediated activation of the GCLC reporter. We

demonstrate that TGF-beta increased ATF3 protein levels, as did

transient overexpression of Smad3E. Ectopic expression of ATF3 was

sufficient to suppress the GCLC reporter activity, as well as

endogenous GCLC expression. These results demonstrate that Smad3-

ATF3 signaling mediates TGF-beta repression of ARE-dependent Phase

II gene expression and potentially provide critical insight into

mechanisms underlying TGF-beta1 function in carcinogenesis, tissue

repair, and fibrosis.

PMID: 15629866 [PubMed - indexed for MEDLINE]

----------------------------------

Transcription Factor Nrf2 Plays a Pivotal Role in Protection against

Elastase-Induced Pulmonary Inflammation and Emphysema.

Ishii Y, Itoh K, Morishima Y, Kimura T, Kiwamoto T, Iizuka T, Hegab

AE, Hosoya T, Nomura A, Sakamoto T, Yamamoto M, Sekizawa K.

Department of Respiratory Medicine.

Emphysema is one of the major pathological abnormalities associated

with chronic obstructive pulmonary disease. The

protease/antiprotease imbalance and inflammation resulting from

oxidative stress have been attributed to the pathogenesis of

emphysema. Nrf2 is believed to protect against oxidative tissue

damage through the transcriptional activation of a battery of

antioxidant enzymes. In this study, we investigated the protective

role of Nrf2 in the development of emphysema using elastase-induced

emphysema as our model system. We found that elastase-provoked

emphysema was markedly exacerbated in Nrf2-knockout (KO) mice

compared with wild-type mice. The severity of emphysema in Nrf2-KO

mice correlated intimately with the degree of lung inflammation in

the initial stage of elastase treatment. The highly inducible

expression of antioxidant and antiprotease genes observed in wild-

type alveolar macrophages was significantly attenuated in the lungs

of Nrf2-KO mice. Interestingly, transplantation of wild-type bone

marrow cells into Nrf2-KO mice retarded the development of initial

lung inflammation and subsequent emphysema, and this improvement

correlated well with the appearance of macrophages expressing Nrf2-

regulated antiprotease and antioxidant genes. Thus, Nrf2 appears to

exert its protective effects through the transcriptional activation

of antiprotease and antioxidant genes in alveolar macrophages.

-----------------------------------

sulforaphane analogue that potently activates the Nrf2-dependent

detoxification pathway.

Morimitsu Y, Nakagawa Y, Hayashi K, Fujii H, Kumagai T, Nakamura Y,

Osawa T, Horio F, Itoh K, Iida K, Yamamoto M, Uchida K.

Laboratory of Food and Biodynamics and the Division of Biomodeling,

Graduate School of Bioagricultural Sciences, Nagoya University,

Nagoya 464-8601, Japan.

Exposure of cells to a wide variety of chemoprotective compounds

confers resistance to a broad set of carcinogens. For a subset of

the chemoprotective compounds, protection is generated by an

increase in the abundance of the protective phase II detoxification

enzymes, such as glutathione S-transferase (GST). We have recently

developed a cell culture system, using rat liver epithelial RL 34

cells, that potently responds to the phenolic antioxidants resulting

in the induction of GST activity (Kawamoto, Y., Nakamura, Y., Naito,

Y., Torii, Y., Kumagai, T., Osawa, T., Ohigashi, H., Satoh, K.,

Imagawa, M., and Uchida, K. (2000) J. Biol. Chem. 275, 11291-11299.)

In the present study, we investigated the phase II-inducing potency

of an isothiocyanate compound in vitro and in vivo and examined a

possible induction mechanism. Based on an extensive screening of

vegetable extracts for GST inducer activity in RL34 cells, we found

Japanese horseradish, wasabi (Wasabia japonica, syn. Eutrema

wasabi), as the richest source and identified 6-methylsulfinylhexyl

isothiocyanate (6-HITC), an analogue of sulforaphane (4-

methylsulfinylbutyl isothiocyanate) isolated from broccoli, as the

major GST inducer in wasabi. 6-HITC potently induced both class

alpha GSTA1 and class pi GSTP1 isozymes in RL34 cells. In animal

experiments, we found that 6-MSHI was rapidly absorbed into the body

and induced hepatic phase II detoxification enzymes more potently

than sulforaphane. The observations that (i) 6-HITC activated the

antioxidant response element (ARE), (ii) 6-HITC induced nuclear

localization of the transcription factor Nrf2 that binds to ARE, and

(iii) the induction of phase II enzyme genes by 6-HITC was

completely abrogated in the nrf2-deficient mice, suggest that 6-HITC

is a potential activator of the Nrf2/ARE-dependent detoxification

pathway.

This list is intended for patients to share personal experiences with each

other, not to give medical advice. If you are interested in any treatment

discussed here, please consult your doctor.

[Guest guest]

I really didnt know what TGF-b did - how interesting that it inhibits phase II

detoxification! They have tested cytokine levels repeatedly in CFS and TGF-b is

the only one, as I remember, that time and time again comes up increased in CFS.

That certainly ties with increased oxidative stress and toxin build up in CFS.

Very interesting.

jasonlbreckenridge <jasonlbreckenridge@...> wrote: High levels of

TGF-beta1 are consistenly found in CFS. Neurophil

apoptosis study showed this was the net effect. Macrophaes probably

engulf and release the excess elastase.

NRF2 is pivotal for phase 2 detox and corrects protease/antiprotease

balance, including excess elastase.

http://www.lef.org/magazine/mag2005/sep2005_cover_dna_02.htm

Wasabi contains the most potent Phase II detox inducer for NRF2,

which is apparently a potent metabolite of broccoli's sulforaphane.

All 3 studies below support this.

---------------------------------------

Smad3-ATF3 signaling mediates TGF-beta suppression of genes encoding

Phase II detoxifying proteins.

Bakin AV, Stourman NV, Sekhar KR, Rinehart C, Yan X, Meredith MJ,

Arteaga CL, Freeman ML.

Department of Cancer Genetics, Roswell Park Cancer Institute,

Buffalo, NY 14263, USA. andrei.bakin@...

This study provides evidence that in mammary epithelial cells the

pluripotent cytokine TGF-beta1 repressed expression of multiple

genes involved in Phase II detoxification. GCLC, the gene that

encodes the catalytic subunit of the enzyme glutamate cysteine

ligase, the rate-limiting enzyme in the biosynthesis of glutathione,

was used as a molecular surrogate for investigating the mechanisms

by which TGF-beta suppressed Phase II gene expression. TGF-beta was

found to suppress luciferase reporter activity mediated by the human

GCLC proximal promoter, as well as reporter activity mediated by the

GCLC antioxidant response element, ARE4. TGF-beta downregulated

expression of endogenous GCLC mRNA and GCLC protein. TGF-beta

suppression of the Phase II genes correlated with a decrease in

cellular glutathione and an increase in cellular reactive oxygen

species. Ectopic expression of constitutively active Smad3E was

sufficient to inhibit both reporters in the absence of TGF-beta,

whereas dominant negative Smad3A blocked TGF-beta suppression.

Smad3E suppressed Nrf2-mediated activation of the GCLC reporter. We

demonstrate that TGF-beta increased ATF3 protein levels, as did

transient overexpression of Smad3E. Ectopic expression of ATF3 was

sufficient to suppress the GCLC reporter activity, as well as

endogenous GCLC expression. These results demonstrate that Smad3-

ATF3 signaling mediates TGF-beta repression of ARE-dependent Phase

II gene expression and potentially provide critical insight into

mechanisms underlying TGF-beta1 function in carcinogenesis, tissue

repair, and fibrosis.

PMID: 15629866 [PubMed - indexed for MEDLINE]

----------------------------------

Transcription Factor Nrf2 Plays a Pivotal Role in Protection against

Elastase-Induced Pulmonary Inflammation and Emphysema.

Ishii Y, Itoh K, Morishima Y, Kimura T, Kiwamoto T, Iizuka T, Hegab

AE, Hosoya T, Nomura A, Sakamoto T, Yamamoto M, Sekizawa K.

Department of Respiratory Medicine.

Emphysema is one of the major pathological abnormalities associated

with chronic obstructive pulmonary disease. The

protease/antiprotease imbalance and inflammation resulting from

oxidative stress have been attributed to the pathogenesis of

emphysema. Nrf2 is believed to protect against oxidative tissue

damage through the transcriptional activation of a battery of

antioxidant enzymes. In this study, we investigated the protective

role of Nrf2 in the development of emphysema using elastase-induced

emphysema as our model system. We found that elastase-provoked

emphysema was markedly exacerbated in Nrf2-knockout (KO) mice

compared with wild-type mice. The severity of emphysema in Nrf2-KO

mice correlated intimately with the degree of lung inflammation in

the initial stage of elastase treatment. The highly inducible

expression of antioxidant and antiprotease genes observed in wild-

type alveolar macrophages was significantly attenuated in the lungs

of Nrf2-KO mice. Interestingly, transplantation of wild-type bone

marrow cells into Nrf2-KO mice retarded the development of initial

lung inflammation and subsequent emphysema, and this improvement

correlated well with the appearance of macrophages expressing Nrf2-

regulated antiprotease and antioxidant genes. Thus, Nrf2 appears to

exert its protective effects through the transcriptional activation

of antiprotease and antioxidant genes in alveolar macrophages.

-----------------------------------

sulforaphane analogue that potently activates the Nrf2-dependent

detoxification pathway.

Morimitsu Y, Nakagawa Y, Hayashi K, Fujii H, Kumagai T, Nakamura Y,

Osawa T, Horio F, Itoh K, Iida K, Yamamoto M, Uchida K.

Laboratory of Food and Biodynamics and the Division of Biomodeling,

Graduate School of Bioagricultural Sciences, Nagoya University,

Nagoya 464-8601, Japan.

Exposure of cells to a wide variety of chemoprotective compounds

confers resistance to a broad set of carcinogens. For a subset of

the chemoprotective compounds, protection is generated by an

increase in the abundance of the protective phase II detoxification

enzymes, such as glutathione S-transferase (GST). We have recently

developed a cell culture system, using rat liver epithelial RL 34

cells, that potently responds to the phenolic antioxidants resulting

in the induction of GST activity (Kawamoto, Y., Nakamura, Y., Naito,

Y., Torii, Y., Kumagai, T., Osawa, T., Ohigashi, H., Satoh, K.,

Imagawa, M., and Uchida, K. (2000) J. Biol. Chem. 275, 11291-11299.)

In the present study, we investigated the phase II-inducing potency

of an isothiocyanate compound in vitro and in vivo and examined a

possible induction mechanism. Based on an extensive screening of

vegetable extracts for GST inducer activity in RL34 cells, we found

Japanese horseradish, wasabi (Wasabia japonica, syn. Eutrema

wasabi), as the richest source and identified 6-methylsulfinylhexyl

isothiocyanate (6-HITC), an analogue of sulforaphane (4-

methylsulfinylbutyl isothiocyanate) isolated from broccoli, as the

major GST inducer in wasabi. 6-HITC potently induced both class

alpha GSTA1 and class pi GSTP1 isozymes in RL34 cells. In animal

experiments, we found that 6-MSHI was rapidly absorbed into the body

and induced hepatic phase II detoxification enzymes more potently

than sulforaphane. The observations that (i) 6-HITC activated the

antioxidant response element (ARE), (ii) 6-HITC induced nuclear

localization of the transcription factor Nrf2 that binds to ARE, and

(iii) the induction of phase II enzyme genes by 6-HITC was

completely abrogated in the nrf2-deficient mice, suggest that 6-HITC

is a potential activator of the Nrf2/ARE-dependent detoxification

pathway.

This list is intended for patients to share personal experiences with each

other, not to give medical advice. If you are interested in any treatment

discussed here, please consult your doctor.