机械信号:分子机制,生物功能,疾病和治疗点

In multicellular organisms, many molecules transmit signals between cells to pass information. These signals vary in complexity and include small peptides, nucleotides, steroids, fatty acid derivatives, and dissolved gases such as nitric oxide. Some signaling molecules diffuse through the plasma membrane to act locally between neighboring cells or travel long distances. Others remain attached to the cell surface, transmitting information to other cells only when they make contact. In some...

Despite the protective membrane that separates a cell from the environment, cells need the ability to detect and respond to environmental changes. Additionally, cells often need to communicate with one another. Unicellular and multicellular organisms use a variety of cell signaling mechanisms to communicate with the environment.
Cells respond to many types of information, often through receptor proteins positioned on the membrane. For example, skin cells respond to and transmit touch...

A signaling cascade is a series of events that facilitates the transmission of information within or between cells, culminating in a targeted response in the recipient cell. As chemical messengers, hormones are pivotal in initiating and modulating these intricate signaling cascades based on their solubility.
Lipid-soluble hormones, such as steroid hormones, demonstrate an intracellular action. These hormones traverse cell membranes due to their lipid nature. Once inside the target cell, they...

Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli.
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...

Bacterial signaling can occur within bacteria (intracellular) or between bacteria (intercellular). At times, a group of bacteria behaves like a community. To achieve this, they engage in quorum sensing, the perception of higher cell density that causes changes in gene expression. Quorum sensing involves both extracellular and intracellular signaling. The signaling cascade starts with a molecule called an autoinducer (AI). Individual bacteria produce AIs that move out of the bacterial cell...

Mechanically-gated ion channels are proteins found in eukaryotic and prokaryotic cell membranes that open in response to mechanical stress. Tension, compression, swelling, and shear stress can alter the conformation of the protein, opening a transmembrane channel that allows the passage of ions for signal transmission. In eukaryotes, mechanically-gated channels are distributed in several regions like the neurons, lungs, skin, bladder, and heart, where they play critical roles in numerous...