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Microcystin-LR causes the collapse of actin filaments in primary human hepatocytes

Tina Batista1, Georges de Sousa, Jerneja Strupi Suput

  • 1Institute of Pathophysiology, School of Medicine, University of Ljubljana, Zaloska 4, 1000 Ljubljana, Slovenia.

Aquatic Toxicology (Amsterdam, Netherlands)
|August 23, 2003
PubMed

Insights

Microcystin-LR (MCLR) is toxic to human liver cells, causing cell damage and death. This study confirms MCLR

Area of Science:

  • Hepatology
  • Toxicology
  • Cell Biology

Background:

  • Microcystin-LR (MCLR) is a cyanobacterial toxin known to inhibit protein phosphatases 1 and 2A.
  • MCLR induces apoptosis and cytoskeletal alterations in rat hepatocytes.
  • Human fatalities and illnesses linked to cyanobacterial blooms suggest potential toxicity to humans.

Purpose of the Study:

  • To investigate the toxic effects of Microcystin-LR (MCLR) on primary human hepatocytes.
  • To characterize the cellular and morphological changes induced by MCLR exposure in human liver cells.

Main Methods:

  • Primary human hepatocytes were exposed to varying concentrations of MCLR (12.5-50 nM) for 3, 6, and 9 hours.
  • Cells were fixed and stained with fluorescent probes targeting actin filaments and nuclei.
  • Spectral laser-scanning confocal microscopy was employed to visualize cellular alterations.

Main Results:

  • MCLR exposure caused the actin mesh in human hepatocytes to collapse centrally.
  • Significant cellular changes were observed, including blebbing, fragmentation, and cell-cell separation.
  • Nuclear condensation was evident in MCLR-treated hepatocytes, indicative of apoptosis.

Conclusions:

  • Microcystin-LR (MCLR) demonstrates significant toxicity towards primary human hepatocytes.
  • The observed cellular damage mechanisms in human hepatocytes mirror those in rat models.
  • MCLR is implicated as a potential cause of liver failure in acute cyanobacterial poisoning cases.

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