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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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Related in: MedlinePlus

Representative traces show that depolarizing voltage steps elicited inward current in IECs and the inward current was inhibited by nifedipine (5 μM).
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Related In: Results  -  Collection


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fig2: Representative traces show that depolarizing voltage steps elicited inward current in IECs and the inward current was inhibited by nifedipine (5 μM).

Mentions: To verify the presence of voltage-gated Ca2+ channels, cells underwent patch clamping. Cells showed voltage-sensitive Ca2+ currents that could be blocked by nifedipine (5 μM; Figure 2).


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)

Representative traces show that depolarizing voltage steps elicited inward current in IECs and the inward current was inhibited by nifedipine (5 μM).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig2: Representative traces show that depolarizing voltage steps elicited inward current in IECs and the inward current was inhibited by nifedipine (5 μM).
Mentions: To verify the presence of voltage-gated Ca2+ channels, cells underwent patch clamping. Cells showed voltage-sensitive Ca2+ currents that could be blocked by nifedipine (5 μM; Figure 2).

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