Related Experiment Video

Updated: Aug 6, 2026

Dissection of Adult Mouse Utricle and Adenovirus-mediated Supporting-cell Infection
11:13

Dissection of Adult Mouse Utricle and Adenovirus-mediated Supporting-cell Infection

Published on: March 28, 2012

Regulation of p27Kip1 during gentamicin mediated hair cell death

C Torchinsky1, E P Messana, M Arsura

  • 1Laboratory for Cellular and Molecular Hearing Research, Department of Otolarynology, Children's Hospital-Boston, MA 02115, USA.

Journal of Neurocytology
|July 19, 2000
PubMed

Insights

Cyclin Dependent Kinase inhibitors (CKIs), like p27(Kip1), protect cells from apoptosis in vivo. Downregulation of p27(Kip1) in avian auditory hair cells undergoing programmed cell death suggests a general role in apoptosis.

Area of Science:

  • Cell Biology
  • Auditory Neuroscience
  • Molecular Biology

Background:

  • Cyclin Dependent Kinase inhibitors (CKIs) regulate the cell cycle and can protect cells from apoptosis in vitro.
  • The in vivo role of p27(Kip1) in apoptosis, particularly in auditory hair cells, remains largely unknown.
  • The avian basilar papilla (BP) provides a model to study hair cell death and CKI expression.

Purpose of the Study:

  • To investigate the in vivo protective role of p27(Kip1) in auditory hair cells.
  • To characterize the expression pattern of p27(Kip1) in the avian basilar papilla during induced hair cell death.
  • To determine if p27(Kip1) downregulation is associated with programmed cell death in hair cells.

Main Methods:

  • Systemic aminoglycoside treatment to induce hair cell death in the avian basilar papilla.
  • Confocal and immunofluorescence microscopy to analyze p27(Kip1) expression.
  • Double labeling for p27(Kip1) and myosin VIIa (hair cell marker) to identify dying hair cells.

Main Results:

  • In normal mature birds, p27(Kip1) is expressed in the nuclei of both hair cells and supporting cells in the BP.
  • Gentamicin treatment induced hair cell death, with many TUNEL-positive and pyknotic nuclei observed.
  • Dying hair cells ejected from the epithelium were myosin VIIa-positive but p27(Kip1)-negative, indicating downregulation of p27(Kip1) during apoptosis.
  • Damaged hair cells within the epithelium showed cytoplasmic, but not nuclear, p27(Kip1) localization.

Conclusions:

  • p27(Kip1) downregulation is observed in avian auditory hair cells undergoing programmed cell death.
  • These findings support the hypothesis that p27(Kip1) protects cells from apoptosis in vivo.
  • The downregulation of p27(Kip1) may be a general characteristic of programmed cell death across different cell types.

More Related Videos

Initiating Differentiation in Immortalized Multipotent Otic Progenitor Cells12:17

Initiating Differentiation in Immortalized Multipotent Otic Progenitor Cells

Published on: January 2, 2016

Mechanism of Kemeng Fang's Inhibition of Podocyte Apoptosis in Rats with Membranous Nephropathy through the PI3K/AKT Signaling Pathway07:15

Mechanism of Kemeng Fang's Inhibition of Podocyte Apoptosis in Rats with Membranous Nephropathy through the PI3K/AKT Signaling Pathway

Published on: August 23, 2024

Related Concept Videos

Negative Regulator Molecules01:23

Negative Regulator Molecules

Positive regulators allow a cell to advance through cell cycle checkpoints. Negative regulators have an equally important role as they terminate a cell’s progression through the cell cycle—or pause it—until the cell meets specific criteria.
DNA Damage can Stall the Cell Cycle02:36

DNA Damage can Stall the Cell Cycle

In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...
Inhibition of Cdk Activity02:34

Inhibition of Cdk Activity

The orderly progression of the cell cycle depends on the activation of Cdk protein by binding to its cyclin partner. However, the cell cycle must be restricted when undergoing abnormal changes. Most cancers correlate to the deregulated cell cycle, and since Cdks are a central component of the cell cycle, Cdk inhibitors are extensively studied to develop anticancer agents. For instance, cyclin D associates with several Cdks, such as Cdk 4/6, to form an active complex. The cyclin D-Cdk4/6 complex...
Abnormal Proliferation02:23

Abnormal Proliferation

Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the daughter...
DNA Damage Can Stall the Cell Cycle02:36

DNA Damage Can Stall the Cell Cycle

In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...
Determination of Multiple Dosing Parameters: Steady-State, Minimum and Maximum Concentrations01:15

Determination of Multiple Dosing Parameters: Steady-State, Minimum and Maximum Concentrations

Gentamicin, an aminoglycoside antibiotic, is commonly administered via intermittent intravenous infusion to treat severe infections. An intermittent one-hour infusion of gentamicin, administered at eight-hour intervals, allows for precise control of plasma drug concentrations, minimizing toxicity while ensuring therapeutic efficacy. Pharmacokinetic principles govern the dynamics of plasma concentrations and can be mathematically described using specific equations.The plasma drug concentration...