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Ischemia-induced apoptosis of intestinal epithelial cells correlates with altered integrin distribution and disassembly of F-actin triggered by calcium overload.

Jia Z, Chen Q, Qin H - J. Biomed. Biotechnol. (2012)

Bottom Line: Results.Verapamil attenuated both changes of integrins and F-actin.Conclusions.

View Article: PubMed Central - PubMed

Affiliation: Department of General Surgery, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai 200233, China.

ABSTRACT
The present study examined intestinal epithelial cell (IEC) integrin distribution and disassembly of actin cytoskeleton in response to ischemia-anoxia. Protective effects of calcium channel blocker(CCB) were further examined to explore underlying mechanisms of cellular injury. Materials and Methods. Primary cultures of rat IECs and an in vitro model of ischemia/anoxia were established. IECs were exposed to ischemia/anoxia in the presence and absence of verapamil. The extent of exfoliation was determined using light microscopy while apoptosis rate was measured using flow cytometry. Changes in intracellular calcium, the distribution of integrins and the morphology of F-actin were assessed by confocal microscopy. Results. Detachment and apoptosis of IECs increased following ischemia/anoxia-induced injury. Treatment with verapamil inhibited the detachment and apoptosis. Under control conditions, the strongest fluorescent staining for integrins appeared on the basal surface of IECs while this re-distributed to the apical membrane in response to ischemic injury. Depolymerization of F-actin was also observed in the injured cells. Verapamil attenuated both changes of integrins and F-actin. Conclusions. Redistribution of integrins and disruption of F-actin under ischemia/anoxia injury is associated with IEC detachment and increased apoptosis. These events appeared to be triggered by an increase in Ca(2+)(i) suggesting a potential use for CCB in prevention and treatment of intestinal injury.

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The FCM analyses following staining with annexin V-FITC and PI show the induction of apoptosis in IECs. Background labeling of living cells is found in quadrant 3, whereas quadrant 4 contains apoptotic cells, stained with annexin V-FITC only, and quadrant 2 represents cells that bind to annexin V and PI and is considered to be in late stages of apoptosis, exhibiting disrupted cell membrane or necrosis. Compared with cells in control group, the percentage of apoptotic cells increased in injury group. After treatment with verapamil, the percentage of apoptotic cells decreased compared with that in injury group.
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fig3: The FCM analyses following staining with annexin V-FITC and PI show the induction of apoptosis in IECs. Background labeling of living cells is found in quadrant 3, whereas quadrant 4 contains apoptotic cells, stained with annexin V-FITC only, and quadrant 2 represents cells that bind to annexin V and PI and is considered to be in late stages of apoptosis, exhibiting disrupted cell membrane or necrosis. Compared with cells in control group, the percentage of apoptotic cells increased in injury group. After treatment with verapamil, the percentage of apoptotic cells decreased compared with that in injury group.

Mentions: The extent of exfoliation and apoptosis in response to ischemia/anoxia is shown in Table 1 and Figure 3. Both parameters were significantly elevated in the injury group compared to the control group (ER: 25.6 ± 8.2 versus 4.8 ± 1.6%, P < 0.01; AR: 68.6 ± 4.2 versus 34.5 ± 3.6%, P < 0.01). After treatment with verapamil, the IECs showed a significantly lower degree of detachment and apoptosis than those seen in the injury group (ER: 17.6 ± 6.8 versus 25.6 ± 8.2%, P < 0.05; AR: 55.6 ± 4.2 versus 68.6 ± 4.2, P < 0.05).


Ischemia-induced apoptosis of intestinal epithelial cells correlates with altered integrin distribution and disassembly of F-actin triggered by calcium overload.

Jia Z, Chen Q, Qin H - J. Biomed. Biotechnol. (2012)

The FCM analyses following staining with annexin V-FITC and PI show the induction of apoptosis in IECs. Background labeling of living cells is found in quadrant 3, whereas quadrant 4 contains apoptotic cells, stained with annexin V-FITC only, and quadrant 2 represents cells that bind to annexin V and PI and is considered to be in late stages of apoptosis, exhibiting disrupted cell membrane or necrosis. Compared with cells in control group, the percentage of apoptotic cells increased in injury group. After treatment with verapamil, the percentage of apoptotic cells decreased compared with that in injury group.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3369571&req=5

fig3: The FCM analyses following staining with annexin V-FITC and PI show the induction of apoptosis in IECs. Background labeling of living cells is found in quadrant 3, whereas quadrant 4 contains apoptotic cells, stained with annexin V-FITC only, and quadrant 2 represents cells that bind to annexin V and PI and is considered to be in late stages of apoptosis, exhibiting disrupted cell membrane or necrosis. Compared with cells in control group, the percentage of apoptotic cells increased in injury group. After treatment with verapamil, the percentage of apoptotic cells decreased compared with that in injury group.
Mentions: The extent of exfoliation and apoptosis in response to ischemia/anoxia is shown in Table 1 and Figure 3. Both parameters were significantly elevated in the injury group compared to the control group (ER: 25.6 ± 8.2 versus 4.8 ± 1.6%, P < 0.01; AR: 68.6 ± 4.2 versus 34.5 ± 3.6%, P < 0.01). After treatment with verapamil, the IECs showed a significantly lower degree of detachment and apoptosis than those seen in the injury group (ER: 17.6 ± 6.8 versus 25.6 ± 8.2%, P < 0.05; AR: 55.6 ± 4.2 versus 68.6 ± 4.2, P < 0.05).

Bottom Line: Results.Verapamil attenuated both changes of integrins and F-actin.Conclusions.

View Article: PubMed Central - PubMed

Affiliation: Department of General Surgery, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai 200233, China.

ABSTRACT
The present study examined intestinal epithelial cell (IEC) integrin distribution and disassembly of actin cytoskeleton in response to ischemia-anoxia. Protective effects of calcium channel blocker(CCB) were further examined to explore underlying mechanisms of cellular injury. Materials and Methods. Primary cultures of rat IECs and an in vitro model of ischemia/anoxia were established. IECs were exposed to ischemia/anoxia in the presence and absence of verapamil. The extent of exfoliation was determined using light microscopy while apoptosis rate was measured using flow cytometry. Changes in intracellular calcium, the distribution of integrins and the morphology of F-actin were assessed by confocal microscopy. Results. Detachment and apoptosis of IECs increased following ischemia/anoxia-induced injury. Treatment with verapamil inhibited the detachment and apoptosis. Under control conditions, the strongest fluorescent staining for integrins appeared on the basal surface of IECs while this re-distributed to the apical membrane in response to ischemic injury. Depolymerization of F-actin was also observed in the injured cells. Verapamil attenuated both changes of integrins and F-actin. Conclusions. Redistribution of integrins and disruption of F-actin under ischemia/anoxia injury is associated with IEC detachment and increased apoptosis. These events appeared to be triggered by an increase in Ca(2+)(i) suggesting a potential use for CCB in prevention and treatment of intestinal injury.

Show MeSH
Related in: MedlinePlus