Keywords

Cholesterol, LDLR, Prostasin, Matriptase, Hypercholesterolemia, T84

Abstract

In the effort to combat hypercholesterolemia and cardiovascular disease, research has turned to studying the effects of serine proteases on the low-density lipoprotein receptor (LDLR), which plays a key role in the diseased states with high LDL levels. Matriptase has been shown to proteolytically shed the extracellular domain (ECD) of the LDLR in the co-translational setting. Prostasin (PRSS8) and matriptase (ST14) are part of a proteolytic activation cascade and it is hypothesized that the coactivation of prostasin and matriptase or a pharmacological perturbation of the steady state could result in LDLR ECD shedding in cells co-expressing the receptor and the proteases. Lentiviral transduction was carried out in the T84 human colon cancer cells endowing prostasin or matriptase over-expression or knocking out the prostasin gene, along with the appropriate vector controls. The protein level changes of the proteases and the potential associative LDLR changes were evaluated by western blotting using the antibodies specific to the LDLR, PRSS8, ST14, or the GAPDH, used as a quantitative control. Prostasin over-expression did not result in an apparent LDLR ECD cleavage, or LDLR protein level changes, with or without an atorvastatin treatment in all the end-point analysis. Cholesterol uptake by the various stable sublines of the T84 was also not affected, with or without the atorvastatin treatment. Future studies will employ an inducible expression system in cells to achieve realtime regulation of the proteases and the LDLR without the systems reverting to a steady state equilibrium before the endpoint analysis.

Thesis Completion Year

2026

Thesis Completion Semester

Spring

Thesis Chair

Chai, Karl

College

College of Medicine

Department

Biomedical Sciences

Thesis Discipline

Biomedical Sciences

Language

English

Access Status

Open Access

Length of Campus Access

None

Campus Location

Orlando (Main) Campus

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