Kallikrein 8

Kallikrein 8 (KLK8), also known as neuropsin, is a serine protease enzyme encoded by the KLK8 gene in humans. This enzyme plays a crucial role in various physiological processes, including skin desquamation, neuronal plasticity, and memory. KLK8 is part of the kallikrein-related peptidase family, a group of enzymes involved in processing and maturation of peptide hormones and other bioactive peptides.

Function

KLK8 is expressed in several tissues, with high levels observed in the brain, particularly in the hippocampus and amygdala, areas known for their involvement in memory formation and emotional responses. In the central nervous system, KLK8 contributes to synaptic plasticity by modulating the cleavage of neural cell adhesion molecules, thereby influencing neuronal communication and memory consolidation.

In the skin, KLK8 participates in the process of desquamation, which is the shedding of the outermost layer of the skin. It achieves this by breaking down the proteins that hold skin cells together, facilitating the natural turnover of skin cells.

Clinical Significance

Alterations in KLK8 expression and activity have been associated with various pathological conditions. In neurology, aberrant KLK8 activity has been linked to neurodegenerative diseases, such as Alzheimer's disease, where it is thought to contribute to the pathological processing of amyloid precursor protein, leading to the accumulation of amyloid-beta plaques.

Furthermore, KLK8 has been implicated in cancer biology. Its expression levels are considered potential biomarkers for the diagnosis and prognosis of certain types of cancers, including ovarian and breast cancer. The enzyme's role in cancer progression is thought to be related to its ability to degrade extracellular matrix components, facilitating tumor invasion and metastasis.

Genetics

The KLK8 gene is located on chromosome 19q13.41 and is part of the larger kallikrein gene cluster. This gene cluster consists of 15 members, all encoding for serine proteases with diverse physiological functions. The regulation of KLK8 gene expression is complex and involves various hormonal and environmental factors, reflecting the enzyme's involvement in multiple physiological and pathological processes.

Research

Research on KLK8 has focused on elucidating its role in the central nervous system and its potential as a therapeutic target. Inhibitors of KLK8 are being explored for their potential to mitigate synaptic dysfunction in neurodegenerative diseases and to improve cognitive deficits. Additionally, the development of specific KLK8 inhibitors is of interest in cancer therapy, aiming to prevent tumor progression and metastasis.

See Also

• Serine protease
• Kallikrein
• Neurodegenerative diseases
• Cancer biomarkers