Association of Rat C-Reactive Protein and Other Pentraxins with Rat Lipoproteins Containing Apolipoproteins E and A1

Abstract

C-Reactive protein (CRP) is a member of the pentraxin family of proteins, ubiquitous components of animal serum. This study suggests that, in serum, rat CRP is complexed with lipoprotein and may interact directly with apolipoprotein E. When mixed with diluted rat serum, radiolabeled rat CRP showed a slightly higher sedimentation coefficient (about 15%) than that of the free protein. Elimination of calcium or addition of O-phosphorylethanolamine (O-PE), a low molecular weight compound that binds tightly to rat CRP in a calcium-dependent manner, abolished this difference. Adsorption of rat serum on a rat CRP affinity gel and elution with PE resulted in the isolation of material containing high levels of apolipoproteins E and A1. The affinity-purified preparation interacted with rat CRP and altered the sedimentation coefficient of the latter to the value observed in whole serum. Conversely, rat CRP increased the sedimentation coefficient of the major component of the affinity-purified material or to diluted rat serum, human serum amyloid P (SAP) and hamster female protein (FP), two other members of the pentraxin protein family, also had slightly higher sedimentation coefficients. In contrast, human CRP showed no evidence of an interaction in rat serum or with the affinity-purified proteins. This selectivity coincided with the ability of these pentraxins to bind to O-PE with high affinity. The sedimentation properties of serum lipoproteins, radiolabeled with [3H]cholesterol, also suggested an interaction with rat CRP.(ABSTRACT TRUNCATED AT 250 WORDS)

Heritability of serum hs-CRP concentration and 5-year changes in the Stanislas family study: association with apolipoprotein E alleles

“…27 Meanwhile, a recent study suggested that the contribution of the e4 allele towards lowering CRP levels is independent and may be by a different mechanism than how statins affect inflammation. 19 However, implication of lipoprotein pathway of the cholesterol transport remained plausible since Schwalbe et al 28 reported that CRP may be complexed with lipoprotein by a direct interaction with the apolipoprotein E molecule, suggesting a direct effect of the APOE e4 allele on hs-CRP concentration.…”

Heritability and Expression of C‐Reactive Protein in Type 2 Diabetes in the Diabetes Heart Study

“…2003). In addition, in a rodent model system it has been proposed (Schwalbe et al 1995) that CRP is complexed with lipoprotein, and may interact directly with apolipoprotein E. Austin et al . (2004) speculated that, given the half‐life of plasma CRP if lipoprotein‐bound‐CRP versus free CRP has a different rate of clearance, CRP concentrations in individuals with different APOE genotypes may be a consequence of the slower VLDL clearance in apoE2, and faster clearance in apoE4, subjects.…”

Biphasic transmittance waveform in the APTT coagulation assay is due to the formation of a Ca++-dependent complex of C-reactive protein with very-low–density lipoprotein and is a novel marker of impending disseminated intravascular coagulation

“…In the rat, CRP was shown to interact with serum components containing apolipoproteins E and A1. 32 The interaction is Ca ϩϩ dependent and is inhibited by O-phosphorylethanolamine, a compound that tightly binds specifically to rat CRP. Bhakdi et al 33 showed that when LDL is modified by exposure to a combination of trypsin, cholesterol esterase, and neuraminidase, it binds CRP and has complement-activating activity.…”