September 2024

As well as causing the proliferation of cells, growth factors can promote differentiation and even the death of cells. For example, the differentiation of neuronal progenitor cells to functional neuronal cells is regulated by so-called neurotrophic growth factors. As with the proliferative growth factors, neurotrophic growth factors initiate a complex cascade of events by binding to receptor proteins that span the cell surface:

Growth factors are crucial proteins in regulating various cellular processes, including differentiation and cell division. Simulation of cell division is triggered when particular growth factors bind cell receptors. This triggers a cascade of events through a series of steps that result in mitosis and cell division.

During strenuous exercise, anaerobic conditions develop in our muscles as cells rapidly use oxygen. Muscle cells switch to an alternative metabolic pathway that releases lactic acid to cope with reduced oxygen levels. When lactic acid builds up, it can cause cramps. Similarly, media depth can dramatically impact oxygen levels in cell culture. Standardizing this variable, or agitation may help to improve data reproducibility and relevance in cell culture.

Most growth factors produce a sigmoidal dose response curve. However, biphasic responses can also be generated, even from a single receptor. The specific reasons underlying a biphasic dose response caused by FGF-2 biding to FGFR1 have been elucidated.

Aptamers, from the Latin word aptus, meaning to fit, are short (20-100 nucleotide) sequences of synthetic DNA, RNA or peptides that can be used for binding to specific target molecules with high sensitivity and biocompatibility. Exosomes have been used to deliver ATP-sensing DNA aptamers in a model of Alzheimer disease.