Mesangial matrix

Mesangial Matrix

The mesangial matrix is a specialized extracellular matrix found within the kidney. It is a crucial component of the glomerulus, a network of tiny blood vessels in the kidney that filters blood to form urine. The mesangial matrix provides structural support to the glomerulus and plays a significant role in the regulation of glomerular filtration.

Structure

The mesangial matrix is composed of mesangial cells and extracellular matrix proteins. The mesangial cells are specialized pericytes, cells that wrap around the endothelial cells of capillaries and venules throughout the body. These cells are responsible for the production and maintenance of the extracellular matrix proteins, which include collagen, fibronectin, and laminin.

Function

The primary function of the mesangial matrix is to provide structural support to the glomerulus. It helps maintain the architecture of the glomerular capillary loops, which is essential for efficient filtration of blood.

In addition to its structural role, the mesangial matrix also plays a role in the regulation of glomerular filtration. It can contract and relax in response to various signals, thereby adjusting the surface area available for filtration.

Furthermore, the mesangial matrix is involved in the phagocytosis of trapped immune complexes and apoptotic cells, a process that helps to prevent inflammation and damage to the glomerulus.

Clinical Significance

Abnormalities in the mesangial matrix can lead to various kidney diseases. For instance, excessive accumulation of mesangial matrix material, a condition known as mesangial matrix expansion, is a common feature of diabetic nephropathy, a serious kidney complication of diabetes.

Similarly, loss of mesangial cells and matrix material can lead to glomerulosclerosis, a condition characterized by scarring of the glomeruli. This can result in decreased kidney function and, ultimately, kidney failure.

See Also

• Kidney
• Glomerulus
• Mesangial cells
• Diabetic nephropathy
• Glomerulosclerosis