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Hypertonicity-induced mitochondrial membrane permeability in renal medullary interstitial cells: protective role of

Li Zhang1, Dong Chen, Zhonghai Chen

  • 1Renal Pathology and Electron Microscopy Laboratory, Department of Pathology, Yale University School of Medicine, New Haven, CT 06520-8023, USA.

Cellular Physiology and Biochemistry : International Journal of Experimental Cellular Physiology, Biochemistry, and Pharmacology
|June 1, 2010
PubMed
Abstract

Insights

Organic osmolytes protect kidney cells from hyperosmotic stress by stabilizing mitochondrial membrane potential (Delta Psi) and preventing apoptosis. This highlights their crucial role in preventing cell death under high-salt conditions.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Physiology

Background:

  • Hyperosmotic stress can trigger cell death via apoptosis when protective osmolyte responses fail.
  • Understanding hypertonicity-induced apoptosis mechanisms is crucial for cellular protection.

Purpose of the Study:

  • To investigate the molecular mechanisms of hypertonicity-induced apoptosis.
  • To determine the protective effects of major organic osmolytes on these pathways.

Main Methods:

  • Western blot and immunofluorescence to assess Bcl2-family proteins, cytochrome c, and apoptosis-inducing factor (AIF).
  • JC-1 and TMRM probes to measure mitochondrial membrane potential (Delta Psi) and permeability transition pore (PTP) opening.

Main Results:

  • Hypertonic conditions increased proapoptotic Bax, cytoplasmic cytochrome c and AIF, and dissipated Delta Psi.
  • Organic osmolytes stabilized Delta Psi and reduced cytoplasmic cytochrome c and AIF levels.

Conclusions:

  • Organic osmolytes prevent hypertonicity-induced apoptosis by stabilizing Delta Psi via PTP stabilization.
  • These findings underscore the vital role of organic osmolytes in protecting medullary kidney cells from hypertonicity-mediated death.

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