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Reactive Oxygen Species in Planarian Regeneration: An Upstream Necessity for Correct Patterning and Brain Formation.

Pirotte N, Stevens AS, Fraguas S, Plusquin M, Van Roten A, Van Belleghem F, Paesen R, Ameloot M, Cebrià F, Artois T, Smeets K - Oxid Med Cell Longev (2015)

Bottom Line: Inhibition of ROS production by diphenyleneiodonium (DPI) or apocynin (APO) causes regeneration defaults at both the anterior and posterior wound sites, resulting in reduced regeneration sites (blastemas) and improper tissue homeostasis.ROS signaling is necessary for early differentiation and inhibition of the ROS burst results in defects on the regeneration of the nervous system and on the patterning process.Our results indicate that ROS are key players in neuroregeneration through interference with the differentiation and patterning processes.

View Article: PubMed Central - PubMed

Affiliation: Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, 3590 Diepenbeek, Belgium.

ABSTRACT
Recent research highlighted the impact of ROS as upstream regulators of tissue regeneration. We investigated their role and targeted processes during the regeneration of different body structures using the planarian Schmidtea mediterranea, an organism capable of regenerating its entire body, including its brain. The amputation of head and tail compartments induces a ROS burst at the wound site independently of the orientation. Inhibition of ROS production by diphenyleneiodonium (DPI) or apocynin (APO) causes regeneration defaults at both the anterior and posterior wound sites, resulting in reduced regeneration sites (blastemas) and improper tissue homeostasis. ROS signaling is necessary for early differentiation and inhibition of the ROS burst results in defects on the regeneration of the nervous system and on the patterning process. Stem cell proliferation was not affected, as indicated by histone H3-P immunostaining, fluorescence-activated cell sorting (FACS), in situ hybridization of smedwi-1, and transcript levels of proliferation-related genes. We showed for the first time that ROS modulate both anterior and posterior regeneration in a context where regeneration is not limited to certain body structures. Our results indicate that ROS are key players in neuroregeneration through interference with the differentiation and patterning processes.

No MeSH data available.


Related in: MedlinePlus

The expression of specific neuronal markers after DPI exposure at 7 days post amputation (7 DPA). The smed-th and smed-tbh expressing cells noticeably increased at the anterior blastemas of DPI-exposed trunk (n = 6/6) and tail fragments (n = 5/5) in comparison to control organisms, while smed-cintillo (trunks: n = 6/6; tails: n = 4/4) and smed-gad (trunks: n = 6/6; tails: n = 4/4) expressing cells were clearly reduced at the anterior sites after DPI exposure (3 μM). At the posterior wound sites of the DPI-exposed trunks, expression of smed-th (n = 6/6), smed-tbh (n = 3/6) and smed-cintillo (n = 4/6) was observed which was absent in the control animals. Expression of the anterior marker smed-ndl-4 was noticeably increased in DPI-exposed trunks (n = 5/6) and tails (n = 3/4). Differences in the expression of these genes are indicated in the figure by red arrow heads. Scale bar: 500 μm.
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fig8: The expression of specific neuronal markers after DPI exposure at 7 days post amputation (7 DPA). The smed-th and smed-tbh expressing cells noticeably increased at the anterior blastemas of DPI-exposed trunk (n = 6/6) and tail fragments (n = 5/5) in comparison to control organisms, while smed-cintillo (trunks: n = 6/6; tails: n = 4/4) and smed-gad (trunks: n = 6/6; tails: n = 4/4) expressing cells were clearly reduced at the anterior sites after DPI exposure (3 μM). At the posterior wound sites of the DPI-exposed trunks, expression of smed-th (n = 6/6), smed-tbh (n = 3/6) and smed-cintillo (n = 4/6) was observed which was absent in the control animals. Expression of the anterior marker smed-ndl-4 was noticeably increased in DPI-exposed trunks (n = 5/6) and tails (n = 3/4). Differences in the expression of these genes are indicated in the figure by red arrow heads. Scale bar: 500 μm.

Mentions: To obtain more information concerning the effect of a diminished ROS burst on the regeneration of the cephalic ganglia, we investigated the formation of various types of neurons after DPI exposure by using additional neuronal and anterior markers (Figure 8). After 7 days of regeneration the expression of smed-cintillo (mechanosensory neurons, [71]) and smed-gad (GABAergic neurons, [72]) was clearly reduced at the anterior site after DPI exposure, which might indicate that there are problems with the differentiation of these neuronal cells. Interestingly, the expression of smed-th (dopaminergic neurons, [73, 74]), smed-tbh (octopaminergic neurons, [22, 75]), and smed-ndl-4 (a FGF receptor-like protein of the nou-darake family [70, 76]) seemed to be upregulated at the anterior blastema in the DPI-exposed trunks and tails in comparison with the control animals. However, the observed accumulation of cells expressing these neuronal genes might be the result of the reduced blastema and the mispatterning of the brain (Figure 7). It is not clear whether there are actually more smed-th-, smed-tbh-, and smed-ndl-4-expressing cells in the blastema or whether they are mispatterned without an additional number of cells. On the other hand, we also observed ectopic expression of smed-th and smed-cintillo in the posterior blastemas in the DPI-exposed trunk fragments while these neurons are normally absent at the posterior wound site. The formation of these neuronal cells in the posterior region suggests that diminished ROS levels result in identity issues of the differentiating neoblasts and that ROS signaling is necessary to not only initiate but also coordinate the differentiation process.


Reactive Oxygen Species in Planarian Regeneration: An Upstream Necessity for Correct Patterning and Brain Formation.

Pirotte N, Stevens AS, Fraguas S, Plusquin M, Van Roten A, Van Belleghem F, Paesen R, Ameloot M, Cebrià F, Artois T, Smeets K - Oxid Med Cell Longev (2015)

The expression of specific neuronal markers after DPI exposure at 7 days post amputation (7 DPA). The smed-th and smed-tbh expressing cells noticeably increased at the anterior blastemas of DPI-exposed trunk (n = 6/6) and tail fragments (n = 5/5) in comparison to control organisms, while smed-cintillo (trunks: n = 6/6; tails: n = 4/4) and smed-gad (trunks: n = 6/6; tails: n = 4/4) expressing cells were clearly reduced at the anterior sites after DPI exposure (3 μM). At the posterior wound sites of the DPI-exposed trunks, expression of smed-th (n = 6/6), smed-tbh (n = 3/6) and smed-cintillo (n = 4/6) was observed which was absent in the control animals. Expression of the anterior marker smed-ndl-4 was noticeably increased in DPI-exposed trunks (n = 5/6) and tails (n = 3/4). Differences in the expression of these genes are indicated in the figure by red arrow heads. Scale bar: 500 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4477255&req=5

fig8: The expression of specific neuronal markers after DPI exposure at 7 days post amputation (7 DPA). The smed-th and smed-tbh expressing cells noticeably increased at the anterior blastemas of DPI-exposed trunk (n = 6/6) and tail fragments (n = 5/5) in comparison to control organisms, while smed-cintillo (trunks: n = 6/6; tails: n = 4/4) and smed-gad (trunks: n = 6/6; tails: n = 4/4) expressing cells were clearly reduced at the anterior sites after DPI exposure (3 μM). At the posterior wound sites of the DPI-exposed trunks, expression of smed-th (n = 6/6), smed-tbh (n = 3/6) and smed-cintillo (n = 4/6) was observed which was absent in the control animals. Expression of the anterior marker smed-ndl-4 was noticeably increased in DPI-exposed trunks (n = 5/6) and tails (n = 3/4). Differences in the expression of these genes are indicated in the figure by red arrow heads. Scale bar: 500 μm.
Mentions: To obtain more information concerning the effect of a diminished ROS burst on the regeneration of the cephalic ganglia, we investigated the formation of various types of neurons after DPI exposure by using additional neuronal and anterior markers (Figure 8). After 7 days of regeneration the expression of smed-cintillo (mechanosensory neurons, [71]) and smed-gad (GABAergic neurons, [72]) was clearly reduced at the anterior site after DPI exposure, which might indicate that there are problems with the differentiation of these neuronal cells. Interestingly, the expression of smed-th (dopaminergic neurons, [73, 74]), smed-tbh (octopaminergic neurons, [22, 75]), and smed-ndl-4 (a FGF receptor-like protein of the nou-darake family [70, 76]) seemed to be upregulated at the anterior blastema in the DPI-exposed trunks and tails in comparison with the control animals. However, the observed accumulation of cells expressing these neuronal genes might be the result of the reduced blastema and the mispatterning of the brain (Figure 7). It is not clear whether there are actually more smed-th-, smed-tbh-, and smed-ndl-4-expressing cells in the blastema or whether they are mispatterned without an additional number of cells. On the other hand, we also observed ectopic expression of smed-th and smed-cintillo in the posterior blastemas in the DPI-exposed trunk fragments while these neurons are normally absent at the posterior wound site. The formation of these neuronal cells in the posterior region suggests that diminished ROS levels result in identity issues of the differentiating neoblasts and that ROS signaling is necessary to not only initiate but also coordinate the differentiation process.

Bottom Line: Inhibition of ROS production by diphenyleneiodonium (DPI) or apocynin (APO) causes regeneration defaults at both the anterior and posterior wound sites, resulting in reduced regeneration sites (blastemas) and improper tissue homeostasis.ROS signaling is necessary for early differentiation and inhibition of the ROS burst results in defects on the regeneration of the nervous system and on the patterning process.Our results indicate that ROS are key players in neuroregeneration through interference with the differentiation and patterning processes.

View Article: PubMed Central - PubMed

Affiliation: Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, 3590 Diepenbeek, Belgium.

ABSTRACT
Recent research highlighted the impact of ROS as upstream regulators of tissue regeneration. We investigated their role and targeted processes during the regeneration of different body structures using the planarian Schmidtea mediterranea, an organism capable of regenerating its entire body, including its brain. The amputation of head and tail compartments induces a ROS burst at the wound site independently of the orientation. Inhibition of ROS production by diphenyleneiodonium (DPI) or apocynin (APO) causes regeneration defaults at both the anterior and posterior wound sites, resulting in reduced regeneration sites (blastemas) and improper tissue homeostasis. ROS signaling is necessary for early differentiation and inhibition of the ROS burst results in defects on the regeneration of the nervous system and on the patterning process. Stem cell proliferation was not affected, as indicated by histone H3-P immunostaining, fluorescence-activated cell sorting (FACS), in situ hybridization of smedwi-1, and transcript levels of proliferation-related genes. We showed for the first time that ROS modulate both anterior and posterior regeneration in a context where regeneration is not limited to certain body structures. Our results indicate that ROS are key players in neuroregeneration through interference with the differentiation and patterning processes.

No MeSH data available.


Related in: MedlinePlus