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Expression of TrkC receptors in the developing brain of the Monodelphis opossum and its effect on the development of cortical cells.

Bartkowska K, Gajerska M, Turlejski K, Djavadian RL - PLoS ONE (2013)

Bottom Line: We found that in different neocortical areas located both at the rostral and caudal regions of the cortex, up to 98% of BrdU-labeled cells forming cortical layers (II-VI) had prominently expressed TrkC.The shRNAs were individually tested in transfected cortical progenitor cells grown on culture plates for 2 days.The effects of the shRNA-TrkC constructs were similar: blockade of TrkC receptors decreased the number of Ki67-positive and apoptotic cells, and it did not change the number of TUJ-positive neurons in vitro.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology, Warsaw, Poland.

ABSTRACT
In this study, we investigated the distribution, localization and several various functions of TrkC receptors during development of the Monodelphisopossum brain. Western blotting analysis showed that two different forms of the TrkC receptor, the full-length receptor and one of its truncated forms, are abundantly expressed in the opossum brain. The expression of TrkC receptors was barely detected in the brain of newborn opossums. At postnatal day (P) 3, the expression of full-length TrkC remained at low levels, while moderate expression of the TrkC truncated form was detected. The expression levels of both forms of this protein gradually increased throughout development, peaking at P35. We found that in different neocortical areas located both at the rostral and caudal regions of the cortex, up to 98% of BrdU-labeled cells forming cortical layers (II-VI) had prominently expressed TrkC. To assess which developmental processes of cortical cells are regulated by TrkC receptors, three different shRNAs were constructed. The shRNAs were individually tested in transfected cortical progenitor cells grown on culture plates for 2 days. The effects of the shRNA-TrkC constructs were similar: blockade of TrkC receptors decreased the number of Ki67-positive and apoptotic cells, and it did not change the number of TUJ-positive neurons in vitro. Thus, the lack of TrkC receptors in cultured progenitor cells provided insight on the potential role of these receptors in the regulation of proliferation and cell survival but not in the differentiation of cortical cells.

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Expression of TrkC in the developing cerebral cortex of the opossum.A – Western blotting analysis was performed at P3, P7, P12, P35, P60 and adult animals. GAPDH was used as a loading control. The arrows indicate the positions of the full-length (TrkC-F) and truncated (TrkC-T) TrkC receptors.
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pone-0074346-g003: Expression of TrkC in the developing cerebral cortex of the opossum.A – Western blotting analysis was performed at P3, P7, P12, P35, P60 and adult animals. GAPDH was used as a loading control. The arrows indicate the positions of the full-length (TrkC-F) and truncated (TrkC-T) TrkC receptors.

Mentions: Newborn opossums weighed 108.4 ± 20.6 mg, where their average brain weight was 4.8 ± 1.3 mg and the average weight of the cerebral cortex was 1.3 ± 0.5 mg. However, the homogenized tissue obtained from one opossum cerebral cortex was not sufficient for Western blotting. Thus, cortical tissue lysates were prepared from the pooled cortices of 3-5 opossums at P3, P7 and P12. For older ages, lysates containing the left and right hemispheres from each animal were used. We found that TrkC expression was low at P3, when cortical layer formation begins (Figure 3 A). However, it increases at P7 and P12 (Figure 3 A), a stage when intensive histogenesis occurs, forming cortical layers (the results are presented below).


Expression of TrkC receptors in the developing brain of the Monodelphis opossum and its effect on the development of cortical cells.

Bartkowska K, Gajerska M, Turlejski K, Djavadian RL - PLoS ONE (2013)

Expression of TrkC in the developing cerebral cortex of the opossum.A – Western blotting analysis was performed at P3, P7, P12, P35, P60 and adult animals. GAPDH was used as a loading control. The arrows indicate the positions of the full-length (TrkC-F) and truncated (TrkC-T) TrkC receptors.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3760877&req=5

pone-0074346-g003: Expression of TrkC in the developing cerebral cortex of the opossum.A – Western blotting analysis was performed at P3, P7, P12, P35, P60 and adult animals. GAPDH was used as a loading control. The arrows indicate the positions of the full-length (TrkC-F) and truncated (TrkC-T) TrkC receptors.
Mentions: Newborn opossums weighed 108.4 ± 20.6 mg, where their average brain weight was 4.8 ± 1.3 mg and the average weight of the cerebral cortex was 1.3 ± 0.5 mg. However, the homogenized tissue obtained from one opossum cerebral cortex was not sufficient for Western blotting. Thus, cortical tissue lysates were prepared from the pooled cortices of 3-5 opossums at P3, P7 and P12. For older ages, lysates containing the left and right hemispheres from each animal were used. We found that TrkC expression was low at P3, when cortical layer formation begins (Figure 3 A). However, it increases at P7 and P12 (Figure 3 A), a stage when intensive histogenesis occurs, forming cortical layers (the results are presented below).

Bottom Line: We found that in different neocortical areas located both at the rostral and caudal regions of the cortex, up to 98% of BrdU-labeled cells forming cortical layers (II-VI) had prominently expressed TrkC.The shRNAs were individually tested in transfected cortical progenitor cells grown on culture plates for 2 days.The effects of the shRNA-TrkC constructs were similar: blockade of TrkC receptors decreased the number of Ki67-positive and apoptotic cells, and it did not change the number of TUJ-positive neurons in vitro.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology, Warsaw, Poland.

ABSTRACT
In this study, we investigated the distribution, localization and several various functions of TrkC receptors during development of the Monodelphisopossum brain. Western blotting analysis showed that two different forms of the TrkC receptor, the full-length receptor and one of its truncated forms, are abundantly expressed in the opossum brain. The expression of TrkC receptors was barely detected in the brain of newborn opossums. At postnatal day (P) 3, the expression of full-length TrkC remained at low levels, while moderate expression of the TrkC truncated form was detected. The expression levels of both forms of this protein gradually increased throughout development, peaking at P35. We found that in different neocortical areas located both at the rostral and caudal regions of the cortex, up to 98% of BrdU-labeled cells forming cortical layers (II-VI) had prominently expressed TrkC. To assess which developmental processes of cortical cells are regulated by TrkC receptors, three different shRNAs were constructed. The shRNAs were individually tested in transfected cortical progenitor cells grown on culture plates for 2 days. The effects of the shRNA-TrkC constructs were similar: blockade of TrkC receptors decreased the number of Ki67-positive and apoptotic cells, and it did not change the number of TUJ-positive neurons in vitro. Thus, the lack of TrkC receptors in cultured progenitor cells provided insight on the potential role of these receptors in the regulation of proliferation and cell survival but not in the differentiation of cortical cells.

Show MeSH
Related in: MedlinePlus