Electric field mediated loading of macromolecules in intact yeast cells is critically controlled at the wall level.

Biochimica et biophysica acta · 1995 · Mixed · Low evidence

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MixedLow evidencePaper 4284

Study snapshot

PublicationBiochimica et biophysica acta · 1995

Study typein_vitro

Reported directionMixed

Evidence ratingLow

Abstract

The mechanism of electric field mediated macromolecule transfer inside an intact yeast cell was investigated by observing, under a microscope, the fluorescence associated to cells after pulsation in a buffer containing two different hydrophilic fluorescent dyes. In the case of a small probe such as propidium iodide, a long lived permeabilized state was induced by the field as classically observed on wall free systems. Penetration of a 70 kDa FITC dextran was obtained only by using drastic conditions and only a very limited number of yeast cells which took up macromolecules remained viable. Most dextrans were trapped in the wall. A dramatic improvement in transfer of dextrans was observed when the cells were treated by dithiothreitol before pulsation. A cytoplasmic protein leakage was detected after the electric treatment suggesting that an irreversible damage took place in the walls of many pulsed cells. Electroloading of macromolecules in intact yeast cells appears to be controlled by a field induced short lived alteration of the envelope organization.

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AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typein_vitro

Effect directionmixed

Populationintact yeast cells

Sample sizeNot supplied

ExposureNot supplied

Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

After electric field pulsation, a small dye (propidium iodide) showed a long-lived permeabilized state. Uptake of 70 kDa FITC-dextran occurred only under drastic conditions and few cells that took up macromolecules remained viable; most dextran was trapped in the wall. Pretreatment with dithiothreitol improved dextran transfer, and cytoplasmic protein leakage after electric treatment suggested irreversible wall damage in many pulsed cells.

Outcomes measured

cell membrane/envelope permeabilization
uptake/transfer of fluorescent dyes (propidium iodide, 70 kDa FITC-dextran)
cell viability after uptake
dextran trapping in cell wall
cytoplasmic protein leakage (cell damage)

Limitations

No electric field parameters (strength, pulse duration/number) reported in the abstract
No quantitative results or statistical analysis described in the abstract
Sample size not stated
In vitro yeast-cell model; limited generalizability beyond this system

View raw extracted JSON

{
  "study_type": "in_vitro",
  "exposure": {
    "band": null,
    "source": "pulsed electric field (electroporation/electroloading)",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": "intact yeast cells",
  "sample_size": null,
  "outcomes": [
    "cell membrane/envelope permeabilization",
    "uptake/transfer of fluorescent dyes (propidium iodide, 70 kDa FITC-dextran)",
    "cell viability after uptake",
    "dextran trapping in cell wall",
    "cytoplasmic protein leakage (cell damage)"
  ],
  "main_findings": "After electric field pulsation, a small dye (propidium iodide) showed a long-lived permeabilized state. Uptake of 70 kDa FITC-dextran occurred only under drastic conditions and few cells that took up macromolecules remained viable; most dextran was trapped in the wall. Pretreatment with dithiothreitol improved dextran transfer, and cytoplasmic protein leakage after electric treatment suggested irreversible wall damage in many pulsed cells.",
  "effect_direction": "mixed",
  "limitations": [
    "No electric field parameters (strength, pulse duration/number) reported in the abstract",
    "No quantitative results or statistical analysis described in the abstract",
    "Sample size not stated",
    "In vitro yeast-cell model; limited generalizability beyond this system"
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "electric field",
    "pulsation",
    "electroporation",
    "electroloading",
    "yeast",
    "cell wall",
    "propidium iodide",
    "FITC-dextran",
    "macromolecule transfer",
    "dithiothreitol",
    "protein leakage",
    "viability"
  ],
  "suggested_hubs": []
}

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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1016/0005-2736(95)00181-6
PubMed: 8541294

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