Enhanced extracellular lipid accumulation in acidic environments

Area of Science:

• Biochemistry
• Cardiovascular Biology
• Atherosclerosis Research

Background:

• Atherogenesis involves lipoprotein binding to proteoglycans and modifications.
• These processes are crucial for disease development.
• Previous studies focused on neutral pH, but plaque pH decreases during atherogenesis.

Purpose of the Study:

• To review findings on how acidic pH affects lipoprotein binding and modification.
• To understand the role of extracellular pH in atherogenesis.

Main Methods:

• Review of in-vitro studies on enzyme activity and proteoglycan binding at different pH levels.
• Analysis of the impact of acidic pH on lipoprotein-proteoglycan interactions.

Main Results:

• Enzymes like secretory sphingomyelinase and cathepsins, active at acidic pH (5.5-6.5), hydrolyze lipoproteins.
• Proteoglycan binding of VLDL, IDL, and LDL is significantly increased at acidic pH.
• Acidic pH enhances both lipoprotein binding and modification, amplifying extracellular accumulation.

Conclusions:

• In atherosclerotic lesions with decreased extracellular pH, lipoprotein binding and modification are enhanced.
• This pH-induced amplification accelerates lipoprotein accumulation and disease progression.