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bioRxiv · 10.1101/298208

PCPE2 and SR-BI Partner to Impact Accumulation of Fat in Mice

Xu, H.·Kaul, S.·Kallinger, R.·Thomas, M. J.·Schill, R. L.·Sahoo, D.·Sorci-Thomas, M. G.
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Abstract

LDL receptor knockout mice (LDLr-/-) were crossed with PCPE2 knockout mice to obtain Ldlr-/-,Pcpe2-/- mice. The rationale of these studies was to examine the effects of an extracellular matrix protein, PCPE2, on fat storage in a dyslipidemic mouse model. Male Ldlr-/-, Pcpe2-/- mice were fed a Western diet for 25 weeks and their plasma triglyceride metabolism and triglyceride storage was examined. Interestingly, visceral but not subcutaneous fat pad were smaller in diet-fed Ldlr-/-,Pcpe2-/- mice compared to controls. There was no difference in the fatty acid distribution in triglyceride and cholesteryl esters (CE) among the genotypes. Ldlr-/-, Pcpe2-/- mice have higher plasma triglyceride levels and reduced lipoprotein lipase activity. Immunoprecipitation of SR-BI from cell extracts co-precipitated PCPE2 suggesting that PCPE2 and SR-BI are tightly associated. This work also showed that in the absence of PCPE2 SR-BI does not transfer CE from HDL into the cell. These results suggest that HDL, PCPE2, SR-BI, and possibly LPL are associated in an interactome that is required for CE transport into the cell. In the absence of these interactions lipid transport is significantly disrupted.

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Xu, H., Kaul, S., Kallinger, R., Thomas, M. J., Schill, R. L., Sahoo, D., Sorci-Thomas, M. G.. 2018-04-09. PCPE2 and SR-BI Partner to Impact Accumulation of Fat in Mice. https://doi.org/10.1101/298208

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