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Recombinant Human Erythropoietin Protects Myocardial Cells from Apoptosis via the Janus-Activated Kinase 2/Signal Transducer and Activator of Transcription 5 Pathway in Rats with Epilepsy.

Ma BX, Li J, Li H, Wu SS - Curr Ther Res Clin Exp (2015)

Bottom Line: At different time points after seizure onset, electroencephalogram changes were recorded, and myocardium samples were taken for the detection of myocardial cell apoptosis and expression of JAK2, signal transducer and activator of transcription 5 (STAT5), caspase-3, and bcl-xl mRNAs and proteins.Induction of epilepsy significantly enhanced myocardial cell apoptosis and upregulated the expression of caspase-3 and bcl-xl proteins and JAK2 and STAT5a at both the mRNA and protein levels.These results indicate that myocardial cell apoptosis may contribute to myocardial injury in epilepsy.

View Article: PubMed Central - PubMed

Affiliation: Department of Cardiology, Affiliated Hospital of Binzhou Medical University, Binzhou, China.

ABSTRACT

Objective: To investigate the potential mechanisms underlying the protective effects of recombinant human erythropoietin (rhEPO) and carbamylated EPO (CEPO) against myocardial cell apoptosis in epilepsy.

Methods: Rats were given an intra-amygdala injection of kainic acid to induce epilepsy. Groups of rats were treated with rhEPO or CEPO before induction of epilepsy, whereas additional rats were given a caudal vein injection of AG490, a selective inhibitor of Janus kinase 2 (JAK2). At different time points after seizure onset, electroencephalogram changes were recorded, and myocardium samples were taken for the detection of myocardial cell apoptosis and expression of JAK2, signal transducer and activator of transcription 5 (STAT5), caspase-3, and bcl-xl mRNAs and proteins.

Results: Induction of epilepsy significantly enhanced myocardial cell apoptosis and upregulated the expression of caspase-3 and bcl-xl proteins and JAK2 and STAT5a at both the mRNA and protein levels. Pretreatment with either rhEPO or CEPO reduced the number of apoptotic cells, upregulated bcl-xl expression, and downregulated caspase-3 expression in the myocardium of epileptic rats. Both myocardial JAK2 and STAT5a mRNAs, as well as phosphorylated species of JAK2 and STAT5a, were upregulated in epileptic rats in response to rhEPO-but not to CEPO-pretreatment. AG490 treatment increased apoptosis, upregulated caspase-3 protein expression, and downregulated bcl-xl protein expression in the myocardium of epileptic rats.

Conclusions: These results indicate that myocardial cell apoptosis may contribute to myocardial injury in epilepsy. EPO protects myocardial cells from apoptosis via the JAK2/STAT5 pathway in rats with experimental epilepsy, whereas CEPO exerts antiapoptotic activity perhaps via a pathway independent of JAK2/STAT5 signaling.

No MeSH data available.


Related in: MedlinePlus

Recombinant human erythropoietin (rhEPO) and carbamylated erythropoietin (CEPO) protects myocardial cells from apoptosis in rats with KA-induced epilepsy. Apoptosis was measured in control (ie, phosphate buffered saline) and epileptic rats as well as epileptic rats treated with rhEPO, CEPO, ethanol, or AG490 by terminal deoxynucleotidyl transferase dUTP nick end labeling assay at 0, 2, 6, 12, and 24 hours after the appearance of seizures. The figures show representative images (400×; 24 hours after onset of seizure) of terminal deoxynucleotidyl transferase dUTP nick end labeling staining for apoptotic cells in the myocardium of (A) control and (B) epileptic rats, as well as epileptic rats treated with (C) ethanol, (D) rhEPO, (E) CEPO, or (F) AG490. The nuclei of positive cells were stained brown (shown by arrows).
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f0015: Recombinant human erythropoietin (rhEPO) and carbamylated erythropoietin (CEPO) protects myocardial cells from apoptosis in rats with KA-induced epilepsy. Apoptosis was measured in control (ie, phosphate buffered saline) and epileptic rats as well as epileptic rats treated with rhEPO, CEPO, ethanol, or AG490 by terminal deoxynucleotidyl transferase dUTP nick end labeling assay at 0, 2, 6, 12, and 24 hours after the appearance of seizures. The figures show representative images (400×; 24 hours after onset of seizure) of terminal deoxynucleotidyl transferase dUTP nick end labeling staining for apoptotic cells in the myocardium of (A) control and (B) epileptic rats, as well as epileptic rats treated with (C) ethanol, (D) rhEPO, (E) CEPO, or (F) AG490. The nuclei of positive cells were stained brown (shown by arrows).

Mentions: TUNEL assays were performed to examine whether KA injection induced myocardial cell apoptosis and if EPO and CEPO exert an antiapoptotic effect. As shown in Figure 3 and Table I, apoptotic myocardial cells were only occasionally observed in normal control rats. No significant difference was noted in the extent of apoptosis between the normal control and PBS groups (P > 0.05). In the epilepsy group, the number of apoptotic myocardial cells began to increase rapidly 2 hours after the onset of seizures. Apoptosis increased with time, peaking at 24 hours; at 24 hours apoptosis was significantly greater in the epilepsy group compared with the PBS group (P < 0.01). Pretreatment with either EPO or CEPO reduced the number of apoptotic myocardial cells in epileptic rats. At 24 hours the extent of apoptosis was significantly lower (P < 0.01) in both the EPO (15.127% [3.427%]) and CEPO (14.580% [3.104%]) groups compared with the untreated epilepsy group (19.648% [2.191%]). However, there was no significant difference between the EPO- and CEPO-treated groups (P > 0.05). AG490 treatment resulted in a time-dependent increase in the number of apoptotic myocardial cells in epileptic rats. The extent of apoptosis at 24 hours was significantly higher in the AG490 group compared with the ethanol control group (P < 0.01). Additionally, the apoptosis rates at 2, 6, 12, and 24 hours were significantly higher in the AG490 group than in either the EPO- or CEPO-treated group (all P values < 0.01).


Recombinant Human Erythropoietin Protects Myocardial Cells from Apoptosis via the Janus-Activated Kinase 2/Signal Transducer and Activator of Transcription 5 Pathway in Rats with Epilepsy.

Ma BX, Li J, Li H, Wu SS - Curr Ther Res Clin Exp (2015)

Recombinant human erythropoietin (rhEPO) and carbamylated erythropoietin (CEPO) protects myocardial cells from apoptosis in rats with KA-induced epilepsy. Apoptosis was measured in control (ie, phosphate buffered saline) and epileptic rats as well as epileptic rats treated with rhEPO, CEPO, ethanol, or AG490 by terminal deoxynucleotidyl transferase dUTP nick end labeling assay at 0, 2, 6, 12, and 24 hours after the appearance of seizures. The figures show representative images (400×; 24 hours after onset of seizure) of terminal deoxynucleotidyl transferase dUTP nick end labeling staining for apoptotic cells in the myocardium of (A) control and (B) epileptic rats, as well as epileptic rats treated with (C) ethanol, (D) rhEPO, (E) CEPO, or (F) AG490. The nuclei of positive cells were stained brown (shown by arrows).
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4644243&req=5

f0015: Recombinant human erythropoietin (rhEPO) and carbamylated erythropoietin (CEPO) protects myocardial cells from apoptosis in rats with KA-induced epilepsy. Apoptosis was measured in control (ie, phosphate buffered saline) and epileptic rats as well as epileptic rats treated with rhEPO, CEPO, ethanol, or AG490 by terminal deoxynucleotidyl transferase dUTP nick end labeling assay at 0, 2, 6, 12, and 24 hours after the appearance of seizures. The figures show representative images (400×; 24 hours after onset of seizure) of terminal deoxynucleotidyl transferase dUTP nick end labeling staining for apoptotic cells in the myocardium of (A) control and (B) epileptic rats, as well as epileptic rats treated with (C) ethanol, (D) rhEPO, (E) CEPO, or (F) AG490. The nuclei of positive cells were stained brown (shown by arrows).
Mentions: TUNEL assays were performed to examine whether KA injection induced myocardial cell apoptosis and if EPO and CEPO exert an antiapoptotic effect. As shown in Figure 3 and Table I, apoptotic myocardial cells were only occasionally observed in normal control rats. No significant difference was noted in the extent of apoptosis between the normal control and PBS groups (P > 0.05). In the epilepsy group, the number of apoptotic myocardial cells began to increase rapidly 2 hours after the onset of seizures. Apoptosis increased with time, peaking at 24 hours; at 24 hours apoptosis was significantly greater in the epilepsy group compared with the PBS group (P < 0.01). Pretreatment with either EPO or CEPO reduced the number of apoptotic myocardial cells in epileptic rats. At 24 hours the extent of apoptosis was significantly lower (P < 0.01) in both the EPO (15.127% [3.427%]) and CEPO (14.580% [3.104%]) groups compared with the untreated epilepsy group (19.648% [2.191%]). However, there was no significant difference between the EPO- and CEPO-treated groups (P > 0.05). AG490 treatment resulted in a time-dependent increase in the number of apoptotic myocardial cells in epileptic rats. The extent of apoptosis at 24 hours was significantly higher in the AG490 group compared with the ethanol control group (P < 0.01). Additionally, the apoptosis rates at 2, 6, 12, and 24 hours were significantly higher in the AG490 group than in either the EPO- or CEPO-treated group (all P values < 0.01).

Bottom Line: At different time points after seizure onset, electroencephalogram changes were recorded, and myocardium samples were taken for the detection of myocardial cell apoptosis and expression of JAK2, signal transducer and activator of transcription 5 (STAT5), caspase-3, and bcl-xl mRNAs and proteins.Induction of epilepsy significantly enhanced myocardial cell apoptosis and upregulated the expression of caspase-3 and bcl-xl proteins and JAK2 and STAT5a at both the mRNA and protein levels.These results indicate that myocardial cell apoptosis may contribute to myocardial injury in epilepsy.

View Article: PubMed Central - PubMed

Affiliation: Department of Cardiology, Affiliated Hospital of Binzhou Medical University, Binzhou, China.

ABSTRACT

Objective: To investigate the potential mechanisms underlying the protective effects of recombinant human erythropoietin (rhEPO) and carbamylated EPO (CEPO) against myocardial cell apoptosis in epilepsy.

Methods: Rats were given an intra-amygdala injection of kainic acid to induce epilepsy. Groups of rats were treated with rhEPO or CEPO before induction of epilepsy, whereas additional rats were given a caudal vein injection of AG490, a selective inhibitor of Janus kinase 2 (JAK2). At different time points after seizure onset, electroencephalogram changes were recorded, and myocardium samples were taken for the detection of myocardial cell apoptosis and expression of JAK2, signal transducer and activator of transcription 5 (STAT5), caspase-3, and bcl-xl mRNAs and proteins.

Results: Induction of epilepsy significantly enhanced myocardial cell apoptosis and upregulated the expression of caspase-3 and bcl-xl proteins and JAK2 and STAT5a at both the mRNA and protein levels. Pretreatment with either rhEPO or CEPO reduced the number of apoptotic cells, upregulated bcl-xl expression, and downregulated caspase-3 expression in the myocardium of epileptic rats. Both myocardial JAK2 and STAT5a mRNAs, as well as phosphorylated species of JAK2 and STAT5a, were upregulated in epileptic rats in response to rhEPO-but not to CEPO-pretreatment. AG490 treatment increased apoptosis, upregulated caspase-3 protein expression, and downregulated bcl-xl protein expression in the myocardium of epileptic rats.

Conclusions: These results indicate that myocardial cell apoptosis may contribute to myocardial injury in epilepsy. EPO protects myocardial cells from apoptosis via the JAK2/STAT5 pathway in rats with experimental epilepsy, whereas CEPO exerts antiapoptotic activity perhaps via a pathway independent of JAK2/STAT5 signaling.

No MeSH data available.


Related in: MedlinePlus