Related Experiment Video
Updated: May 29, 2026
08:34
Precise Visualization of Insulin Receptors A and B in Murine Brain with an RNA In Situ Hybridization Assay
Published on: July 15, 2025
Proinsulin: from hormonal precursor to neuroprotective factor
Enrique J de la Rosa1, Flora de Pablo
13D Lab (Development, Differentiation and Degeneration), Department of Cellular and Molecular Medicine, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas Madrid, Spain.
Frontiers in Molecular Neuroscience
|September 28, 2011
Summary
Proinsulin, a hormone precursor, plays a vital role in nervous system development and cell survival. It shows potential as a neuroprotective molecule, delaying degeneration in conditions like retinitis pigmentosa.
Area of Science:
- Neuroscience
- Developmental Biology
- Endocrinology
Background:
- Proinsulin is primarily known as a precursor to insulin.
- Non-canonical functions of hormone precursors are increasingly recognized in vertebrate development.
- Proinsulin's role beyond metabolic regulation is an emerging area of research.
Purpose of the Study:
- To review the evolutionary origins of proinsulin/insulin signaling.
- To summarize proinsulin expression regulation during development.
- To discuss proinsulin's neuroprotective potential in neural tissues.
Main Methods:
- Review of existing literature on proinsulin and insulin evolution.
- Analysis of studies on proinsulin mRNA regulation in neurogenesis.
- Examination of experimental data on proinsulin's effects in neural development and disease models.
Main Results:
- Proinsulin mRNA is precisely regulated during early neurulation and neurogenesis.
- Proinsulin promotes cell survival in the developing nervous system.
- Proinsulin demonstrated efficacy in preventing cell death and delaying photoreceptor degeneration in a retinitis pigmentosa mouse model.
Conclusions:
- Proinsulin exhibits significant non-canonical functions in neural development.
- Proinsulin holds promise as a therapeutic agent for neurodegenerative diseases.
- Further research into proinsulin's neuroprotective mechanisms is warranted.
Related Concept Videos
01:25Insulin: Biosynthesis, Chemistry, and Preparation
The endoplasmic reticulum (ER) of pancreatic β-cells synthesizes preproinsulin, which consists of a signal peptide, A and B chains, and a C-peptide. Preproinsulin is then cleaved and folded into proinsulin, which translocates to the Golgi apparatus for sorting and packaging into secretory granules. In these granules, enzymatic clipping generates insulin and C-peptide.
Damage or functional impairment of β-cells inhibits insulin production, leading to diabetes. Diabetes treatment primarily uses...
Damage or functional impairment of β-cells inhibits insulin production, leading to diabetes. Diabetes treatment primarily uses...
01:05Insulin Secretory Vesicles
Insulin secretory vesicles release insulin to stimulate blood glucose uptake and regulate carbohydrate metabolism. When the blood glucose levels increase, glucose enters the pancreatic β-islet cells through glucose transporters. Once inside, glucose is metabolized through glycolysis, the citric acid cycle, and the electron transport chain, producing ATP. This increase in ATP concentration closes ATP-sensitive potassium channels, leading to depolarization of the membrane and the opening of...
01:27Glucose Homeostasis: Pancreatic Islets and Insulin Secretion
The pancreatic islets comprising only 1%-2% of the volume are highly vascularized and innervated mini-organs. They contain five endocrine cell types, including β cells that secrete insulin, which is synthesized as a single polypeptide chain, preproinsulin, processed to proinsulin, and finally to insulin and C-peptide. This process is complex and regulated, involving the Golgi complex, the endoplasmic reticulum, and the secretory granules of the β cell.
Insulin and C-peptide are co-secreted in...
Insulin and C-peptide are co-secreted in...
01:28Insulin: The Receptor and Signaling Pathways
Insulin action is mediated through a receptor tyrosine kinase, akin to the IGF-1 receptor. The number of receptors per cell varies significantly, from 40 on erythrocytes to 300,000 on adipocytes and hepatocytes. The insulin receptor consists of linked α/β subunit dimers, forming a heterotetramer glycoprotein with two extracellular α subunits and two β subunits spanning the membrane. The α subunits inhibit the inherent tyrosine kinase activity of the β subunits, but this inhibition is released...
01:30Production of Pharmaceuticals
Industrial insulin production uses genetically engineered E. coli expressing a proinsulin gene controlled by a tryptophan promoter and containing a methionine linker for later cleavage. The cells also carry ampicillin resistance for selective growth. Seed cultures are stored at −80 °C and production begins by thawing a small amount to inoculate starter cultures, which are progressively scaled to a 50,000-L bioreactor. In the bioreactor, E. coli grow in nutrient-rich media under sterile, tightly...
01:26Type I Diabetes II: Pathophysiology
Type 1 diabetes mellitus arises from an immune-mediated destruction of pancreatic β-cells, resulting in an absolute deficiency of insulin. This process develops in genetically susceptible individuals when autoimmunity, environmental exposures, and immunologic dysregulation converge to trigger a targeted attack on the insulin-producing cells of the pancreas. The β-cells are located within the islets of Langerhans and are essential for regulating blood glucose by facilitating cellular uptake of...