Blocking Kallikrein 6 promotes developmental myelination.

Area of Science:

• Neuroscience
• Cell Biology
• Biochemistry

Background:

• Kallikrein related peptidase 6 (Klk6) is a serine protease found in the central nervous system (CNS), highly expressed in oligodendrocytes.
• Klk6 is implicated in demyelinating conditions, but its precise role in oligodendrocyte biology and myelination remains unclear.

Purpose of the Study:

• To investigate the impact of Klk6 gene knockout on CNS developmental myelination.
• To understand the role of Klk6 in regulating oligodendrocyte differentiation and myelin production.

Main Methods:

• Global Klk6 gene knockout mice were used to study spinal cord development.
• Oligodendrocyte progenitor cells (OPCs) were derived from knockout mice or treated with a Klk6 inhibitor (DFKZ-251).
• Myelin protein expression, oligodendrocyte differentiation markers, myelin thickness, signaling pathways, and lipid profiles were analyzed.

Main Results:

• Constitutive loss of Klk6 accelerated oligodendrocyte differentiation and increased myelin protein expression (MBP, PLP, CNPase) and myelin thickness.
• Pro-myelinating signaling pathways (ERK, AKT) and myelin regulatory factors were elevated in Klk6 knockouts.
• Inhibition of Klk6 in OPCs enhanced differentiation and myelin protein production, and increased sphingosine and sphingomyelin levels.

Conclusions:

• Oligodendrocyte-derived Klk6 acts as a rheostat or brake on pro-myelinating signaling, regulating myelin homeostasis.
• Inhibition of Klk6, globally or in OPCs, promotes early oligodendrocyte differentiation and myelin production.
• Targeting Klk6 inhibition offers a potential therapeutic strategy for enhancing CNS myelin repair.