Processed B-type natriuretic peptide is a biomarker of postinterventional restenosis in ischemic heart disease.

BACKGROUND: Restenosis, a condition in which the lesion vessel renarrows after a coronary intervention procedure, remains a limitation in management. A surrogate biomarker for risk stratification of restenosis would be welcome. B-type natriuretic peptide (BNP) is secreted in response to pathologic stress from the heart. Its use as a biomarker of heart failure is well known; however, its diagnostic potential in ischemic heart disease is less explored. Recently, it has been reported that processed forms of BNP exist in the circulation. We hypothesized that circulating processed forms of BNP might be a biomarker of ischemic heart disease. METHODS: We characterized processed forms of BNP by a newly developed mass spectrometry-based detection method combined with immunocapture using commercial anti-BNP antibodies. RESULTS: Measurements of processed forms of BNP by this assay were found to be strongly associated with presence of restenosis. Reduced concentrations of the amino-terminal processed peptide BNP(5-32) relative to BNP(3-32) [as the index parameter BNP(5-32)/BNP(3-32) ratio] were seen in patients with restenosis [median (interquartile range) 1.19 (1.11-1.34), n = 22] vs without restenosis [1.43 (1.22-1.61), n = 83; P < 0.001] in a cross-sectional study of 105 patients undergoing follow-up coronary angiography. A sensitivity of 100% to rule out the presence of restenosis was attained at a ratio of 1.52. CONCLUSIONS: Processed forms of BNP may serve as viable potential biomarkers to rule out restenosis.

Elongation factors are involved in cytokinesis of sea urchin eggs.

Cleavage furrows (CFs) have been isolated from dividing sea urchin eggs and the protein constituents have been analyzed by two-dimensional gel electrophoresis (Fujimoto & Mabuchi, J. Biochem. 122, 518-524, 1997). Two proteins of 51 and 32 kDa, respectively, have been found to be enriched in the CF preparation. Here, we show that these proteins are identical to the protein elongation factor 1alpha (EF-1alpha) and 1beta (EF-1beta), respectively. Furthermore, the CF 51-kDa protein is identical to the 51-kDa protein which had been isolated as a component of the microtubule organizing granules of mitotic sea urchin eggs. The 51-kDa protein bundles F-actin in vitro. This activity is suppressed by Ca(2+)/calmodulin or GTPgammaS. The 32-kDa protein binds EF-1alpha both in vitro and in cell extract, and is shown to suppress the F-actin-bundling activity of the 51-kDa protein. Microinjection of a monoclonal antibody against the 51-kDa protein or that of His-tagged 32-kDa protein into dividing sea urchin eggs at the onset of cleavage leads to failure of cytokinesis. These results strongly suggest that EF-1alpha is involved in maintenance of the structure of the contractile ring and EF-1beta regulates the F-actin-bundling activity of EF-1alpha.

Expression of a putative precursor mRNA for sperm-activating peptide I in accessory cells of the ovary in the sea urchin Hemicentrotus pulcherrimus.

A cDNA clone encoding egg jelly peptide, SAP-I (Gly-Phe-Asp-Leu-Asn-Gly-Gly-Gly-Val-Gly), was isolated from a Hemicentrotus pulcherrimus ovary cDNA library and its nucleotide sequence was determined. The cDNA was 1282 by long and an open reading frame predicted a protein of 334 amino acids containing 5 SAP-I and 7 SAP-I-like decapeptides, each separated by a single lysine residue. The cDNA hybridized to two species of mRNA (1.3 kb and 2.0 kb) from H. pulcherrimus ovaries. Northern blot analysis showed that the 1.3 kb transcripts appeared in ovaries collected from November to April and the 2.0 kb transcripts were detected only in ovaries collected in January. An expression study of the SAM precursor gene, by in situ hybridization with a non-radioactive RNA probe synthesized using the 1.3 kb cDNA as template, demonstrated that abundant SAM precursor transcripts were expressed in the accessory cells, but not in the growing oocytes.