Plasma Membrane Integrity
The plasma membrane isolates the cell from its surroundings and therefore its integrity is critical to cell function and survival. Cells can suffer plasma membrane damage from a variety of stressors in the extracellular and intracellular environment, such as mechanical, chemical, microbial, immune, and intracellular stressors. Plasma membrane integrity is a fundamental aspect of cell biology. In response to injury, cells are equipped with plasma membrane repair mechanisms to promote wound closure. Plasma membrane damage is usually assessed by indirect means, such as entry of cellular impermeable molecules, calcium in-flow or detection of intracellular contents in the extracellular environment. There is an urgent need to develop techniques to directly visualize the measurement and characterization of plasma membrane wounds.
Fig. 1. Five major sources of plasma membrane damage. (Ammendolia D A, et al., 2021)
Services
Regardless of the mechanism by which cells repair the plasma membrane, the ability to induce appropriate physiological membrane damage is important to the study of this process. To study lysosome-mediated plasma membrane repair, CD BioSciences develops multiple methods of chemical disruption and physical disruption to model plasma membrane damage, allowing for controlled damage under conditions similar to those often encountered by mammalian cells in vivo from stress or pathogenic attack. Based on the advantages and disadvantages of each method, we will develop the best solution for your project.
Three-Dimensional Cell Contraction
We cause contraction of fibroblasts, compression of the collagen matrix and tearing of adhesion sites on the cytoplasmic membrane by applying force.
- The process is very rapid and can be done in a single movement.
- Suitable when analyzing highly physiological forms of plasma membrane damage.
Scraping Cells From the Stroma
We scrape a monolayer of adherent cells to cause a tear in the plasma membrane at the point of contact with the substrate and use fluorescent dyes and flow cytometry to quantify the extent of damage and re-closure of adherent cells.
- Allows quantitative assessment of plasma membrane repair of the entire cell population after a defined period of time.
- Can be used to analyze the calcium-dependent extracellular secretion of lysosomal enzymes.
- Less suitable for kinetic analysis of the plasma membrane repair process.
Use of Needles/Syringes
We force cells through a very narrow needle to damage the plasma membrane.
- Suitable for cells that do not adhere well to the substrate.
- The experiment should be repeated three times to ensure reproducibility.
- The number of passages through the needle can be increased or decreased depending on the type and size of the cells.
Use of Glass Beads
We use glass bead abrasion to cause plasma membrane tears, in this method most cells adhere to the substrate in a single layer.
- Allows the use of microscopy after fixation to detect injured cells and analyze changes in protein localization.
- Not suitable for real-time imaging due to the interference of glass beads with the image acquisition process.
- Not suitable for analysis of entire cell populations by flow cytometry.
Use of Pore-Forming Proteins
We use pore-forming toxins from various bacteria as well as proteins from mammalian immune cells, such as perforin, to cause plasma membrane damage.
- Cell damage steps can be closely synchronized.
- The foci formed are highly uniform in size.
- The number of foci can be titrated using different concentrations of pore-forming proteins.
CD BioSciences can meet any reasonable needs of our clients, taking time and budget into consideration for you. Our aim is to be customer-centric and to provide the highest quality services to customers. Our customer service representatives are enthusiastic and trustworthy 24 hours a day, 7 days a week. If you are interested in our services, please feel free to contact us for more information or a detailed discussion.
Reference
- Ammendolia D A, Bement W M, Brumell J H. (2021) Plasma membrane integrity: implications for health and disease[J]. BMC biology. 19(1): 1-29.