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Inhibition of PDE4B suppresses inflammation by increasing expression of the deubiquitinase CYLD.

Komatsu K, Lee JY, Miyata M, Hyang Lim J, Jono H, Koga T, Xu H, Yan C, Kai H, Li JD - Nat Commun (2013)

Bottom Line: Most anti-inflammatory strategies have focused on directly targeting the positive regulator, which often results in significant side effects such as suppression of the host defence response.Importantly, ototopical post-inoculation administration of a PDE4 inhibitor suppresses inflammation in this animal model, thus demonstrating the therapeutic potential of targeting PDE4.These studies provide insights into how inflammation is tightly regulated via the inhibition of its negative regulator and may also lead to the development of new anti-inflammatory therapeutics that upregulate CYLD expression.

View Article: PubMed Central - PubMed

Affiliation: Center for Inflammation, Immunity & Infection and Department of Biology, Georgia State University, 100 Piedmont Avenue, Atlanta, Georgia 30303, USA.

ABSTRACT
The deubiquitinase CYLD acts as a key negative regulator to tightly control overactive inflammation. Most anti-inflammatory strategies have focused on directly targeting the positive regulator, which often results in significant side effects such as suppression of the host defence response. Here, we show that inhibition of phosphodiesterase 4B (PDE4B) markedly enhances upregulation of CYLD expression in response to bacteria, thereby suggesting that PDE4B acts as a negative regulator for CYLD. Interestingly, in Cyld-deficient mice, inhibition of PDE4B no longer suppresses inflammation. Moreover, PDE4B negatively regulates CYLD via specific activation of JNK2 but not JNK1. Importantly, ototopical post-inoculation administration of a PDE4 inhibitor suppresses inflammation in this animal model, thus demonstrating the therapeutic potential of targeting PDE4. These studies provide insights into how inflammation is tightly regulated via the inhibition of its negative regulator and may also lead to the development of new anti-inflammatory therapeutics that upregulate CYLD expression.

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Administration of specific PDE4 inhibitors upregulates CYLD and suppresses inflammation in a mouse otitis media model.mRNA expression of (a) CYLD and (b) pro-inflammatory cytokines was measured in middle ear tissues from C57BL/6J mice ototopically pre- or post-inoculated with Rolipram (50 μg per ear) 3 h before (pretreatment) or 3 h after (post treatment) NTHi inoculation, and inoculated with NTHi for 9 h. (c) Haematoxylin and eosin staining of middle ear tissues from C57BL/6J mice ototopically pre- or post-inoculated with Rolipram (50 μg per ear) 3 h before (pretreatment) or 3 h after (post treatment) NTHi inoculation, and inoculated with NTHi for 9 h (magnification × 400). Scale bar, 20 μm. (d) Thickness of middle ear mucosa in C57BL/6J mice ototopically pre- or post-inoculated with Rolipram and inoculated with NTHi was measured from 15 middle ear tissue sections per experimental group. (e) Mice were transtympanically inoculated with NTHi with or without Rolipram ototopically pre- or post-treatment, and tympanic cavity was observed and recorded under the otoscope. Data in a, b and d are mean±s.d. (n=3 in a and b, and 15 in d). *P<0.05. Statistical analysis was performed using Student’s t-test. Data are representative of three or more independent experiments. CON, control; POST, post-inoculation; PRE, preinoculation.
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f7: Administration of specific PDE4 inhibitors upregulates CYLD and suppresses inflammation in a mouse otitis media model.mRNA expression of (a) CYLD and (b) pro-inflammatory cytokines was measured in middle ear tissues from C57BL/6J mice ototopically pre- or post-inoculated with Rolipram (50 μg per ear) 3 h before (pretreatment) or 3 h after (post treatment) NTHi inoculation, and inoculated with NTHi for 9 h. (c) Haematoxylin and eosin staining of middle ear tissues from C57BL/6J mice ototopically pre- or post-inoculated with Rolipram (50 μg per ear) 3 h before (pretreatment) or 3 h after (post treatment) NTHi inoculation, and inoculated with NTHi for 9 h (magnification × 400). Scale bar, 20 μm. (d) Thickness of middle ear mucosa in C57BL/6J mice ototopically pre- or post-inoculated with Rolipram and inoculated with NTHi was measured from 15 middle ear tissue sections per experimental group. (e) Mice were transtympanically inoculated with NTHi with or without Rolipram ototopically pre- or post-treatment, and tympanic cavity was observed and recorded under the otoscope. Data in a, b and d are mean±s.d. (n=3 in a and b, and 15 in d). *P<0.05. Statistical analysis was performed using Student’s t-test. Data are representative of three or more independent experiments. CON, control; POST, post-inoculation; PRE, preinoculation.

Mentions: We have shown that upregulating expression of CYLD, a key negative regulator of inflammation, via inhibition of its own negative regulator, PDE4B, leads to the suppression of NTHi-induced inflammation. We have already demonstrated that specific PDE4 inhibitors, Rolipram and Roflumilast, when preadministered systemically, upregulated CYLD and suppressed subsequent inflammation in the mouse models of middle ear inflammation (OM) and lung inflammation (Figs 1 and 2). These encouraging data thus prompted us to directly test whether post-inoculation administration of Rolipram has any therapeutic effect on treating middle ear inflammation under clinically relevant condition. Ototopical administration works effectively when the eardrum is perforated either pathologically or surgically by tympanostomy tube insertion363738. Thus, we next evaluated whether ototopical administration of Rolipram upregulates CYLD and suppresses inflammation in the middle ear of mice post NTHi infection. Interestingly, both ototopical pre- and post-inoculation administration of Rolipram upregulated CYLD expression (Fig. 7a) and suppressed inflammation in a mouse OM model in vivo (Fig. 7b–e). Taken together, these data demonstrate that upregulating CYLD expression via pharmacologic inhibition of PDE4 does exhibit significant therapeutic effects in treating inflammatory diseases such as middle ear inflammation (OM).


Inhibition of PDE4B suppresses inflammation by increasing expression of the deubiquitinase CYLD.

Komatsu K, Lee JY, Miyata M, Hyang Lim J, Jono H, Koga T, Xu H, Yan C, Kai H, Li JD - Nat Commun (2013)

Administration of specific PDE4 inhibitors upregulates CYLD and suppresses inflammation in a mouse otitis media model.mRNA expression of (a) CYLD and (b) pro-inflammatory cytokines was measured in middle ear tissues from C57BL/6J mice ototopically pre- or post-inoculated with Rolipram (50 μg per ear) 3 h before (pretreatment) or 3 h after (post treatment) NTHi inoculation, and inoculated with NTHi for 9 h. (c) Haematoxylin and eosin staining of middle ear tissues from C57BL/6J mice ototopically pre- or post-inoculated with Rolipram (50 μg per ear) 3 h before (pretreatment) or 3 h after (post treatment) NTHi inoculation, and inoculated with NTHi for 9 h (magnification × 400). Scale bar, 20 μm. (d) Thickness of middle ear mucosa in C57BL/6J mice ototopically pre- or post-inoculated with Rolipram and inoculated with NTHi was measured from 15 middle ear tissue sections per experimental group. (e) Mice were transtympanically inoculated with NTHi with or without Rolipram ototopically pre- or post-treatment, and tympanic cavity was observed and recorded under the otoscope. Data in a, b and d are mean±s.d. (n=3 in a and b, and 15 in d). *P<0.05. Statistical analysis was performed using Student’s t-test. Data are representative of three or more independent experiments. CON, control; POST, post-inoculation; PRE, preinoculation.
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Related In: Results  -  Collection

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f7: Administration of specific PDE4 inhibitors upregulates CYLD and suppresses inflammation in a mouse otitis media model.mRNA expression of (a) CYLD and (b) pro-inflammatory cytokines was measured in middle ear tissues from C57BL/6J mice ototopically pre- or post-inoculated with Rolipram (50 μg per ear) 3 h before (pretreatment) or 3 h after (post treatment) NTHi inoculation, and inoculated with NTHi for 9 h. (c) Haematoxylin and eosin staining of middle ear tissues from C57BL/6J mice ototopically pre- or post-inoculated with Rolipram (50 μg per ear) 3 h before (pretreatment) or 3 h after (post treatment) NTHi inoculation, and inoculated with NTHi for 9 h (magnification × 400). Scale bar, 20 μm. (d) Thickness of middle ear mucosa in C57BL/6J mice ototopically pre- or post-inoculated with Rolipram and inoculated with NTHi was measured from 15 middle ear tissue sections per experimental group. (e) Mice were transtympanically inoculated with NTHi with or without Rolipram ototopically pre- or post-treatment, and tympanic cavity was observed and recorded under the otoscope. Data in a, b and d are mean±s.d. (n=3 in a and b, and 15 in d). *P<0.05. Statistical analysis was performed using Student’s t-test. Data are representative of three or more independent experiments. CON, control; POST, post-inoculation; PRE, preinoculation.
Mentions: We have shown that upregulating expression of CYLD, a key negative regulator of inflammation, via inhibition of its own negative regulator, PDE4B, leads to the suppression of NTHi-induced inflammation. We have already demonstrated that specific PDE4 inhibitors, Rolipram and Roflumilast, when preadministered systemically, upregulated CYLD and suppressed subsequent inflammation in the mouse models of middle ear inflammation (OM) and lung inflammation (Figs 1 and 2). These encouraging data thus prompted us to directly test whether post-inoculation administration of Rolipram has any therapeutic effect on treating middle ear inflammation under clinically relevant condition. Ototopical administration works effectively when the eardrum is perforated either pathologically or surgically by tympanostomy tube insertion363738. Thus, we next evaluated whether ototopical administration of Rolipram upregulates CYLD and suppresses inflammation in the middle ear of mice post NTHi infection. Interestingly, both ototopical pre- and post-inoculation administration of Rolipram upregulated CYLD expression (Fig. 7a) and suppressed inflammation in a mouse OM model in vivo (Fig. 7b–e). Taken together, these data demonstrate that upregulating CYLD expression via pharmacologic inhibition of PDE4 does exhibit significant therapeutic effects in treating inflammatory diseases such as middle ear inflammation (OM).

Bottom Line: Most anti-inflammatory strategies have focused on directly targeting the positive regulator, which often results in significant side effects such as suppression of the host defence response.Importantly, ototopical post-inoculation administration of a PDE4 inhibitor suppresses inflammation in this animal model, thus demonstrating the therapeutic potential of targeting PDE4.These studies provide insights into how inflammation is tightly regulated via the inhibition of its negative regulator and may also lead to the development of new anti-inflammatory therapeutics that upregulate CYLD expression.

View Article: PubMed Central - PubMed

Affiliation: Center for Inflammation, Immunity & Infection and Department of Biology, Georgia State University, 100 Piedmont Avenue, Atlanta, Georgia 30303, USA.

ABSTRACT
The deubiquitinase CYLD acts as a key negative regulator to tightly control overactive inflammation. Most anti-inflammatory strategies have focused on directly targeting the positive regulator, which often results in significant side effects such as suppression of the host defence response. Here, we show that inhibition of phosphodiesterase 4B (PDE4B) markedly enhances upregulation of CYLD expression in response to bacteria, thereby suggesting that PDE4B acts as a negative regulator for CYLD. Interestingly, in Cyld-deficient mice, inhibition of PDE4B no longer suppresses inflammation. Moreover, PDE4B negatively regulates CYLD via specific activation of JNK2 but not JNK1. Importantly, ototopical post-inoculation administration of a PDE4 inhibitor suppresses inflammation in this animal model, thus demonstrating the therapeutic potential of targeting PDE4. These studies provide insights into how inflammation is tightly regulated via the inhibition of its negative regulator and may also lead to the development of new anti-inflammatory therapeutics that upregulate CYLD expression.

Show MeSH
Related in: MedlinePlus