Alterations in population dynamics of arterial smooth muscle cells during atherogenesis. IV. Evidence for a polyclonal origin of hypercholesterolemic diet induced atherosclerotic lesions in young swine

The purpose of this study was to determine whether atherosclerotic lesions developing in young swine fed hypercholesterolemic (HC) diets were monoclonal or polyclonal in origin. The approach involved labeling arterial cells with tritiated thymidine prior to feeding the HC diet. Baseline swine were sacrificed and radioautography studies carried out to determine baseline labeling indices and grain number distributions in media and in intimal cellular masses (cushions). Remaining swine were then fed an HC diet for 30-60 days before sacrificing and making the same type determinations as with the baseline swine on putative active lesions and media. If a lesion arose from a single cell (or multiple unlabeled cells) labeling indices would be expected to be greatly reduced without a change in grain number patterns. This was not observed in any of the 14 putative lesions that were studied. If the lesion arose from divisions by multiple cells including labeled cells one would expect the proportion of cells with a high number of grains to be decreased, those with low numbers to be increased (since with division half the isotope goes to each daughter cell) and this to be reflected in the grain count. This occurred in 9 of the putative lesions, indicating multicellular origin. In 5 there were neither change in grain number distributions nor reduction in labeling indices. Hence, these showed no division activity during the period of study; they were classified as inactive lesions or preexisting cushions and provide no pertinent information for this study. The final conclusion was that all active lesions observed were polyclonal in origin. Further information was obtained by mathematical analysis on number of divisions made by the originally labeled cells; and considerable heterogeneity was observed, with some not dividing at all and others with progeny going through as many as 4 divisions.link_to_subscribed_fulltex

Population dynamics of arterial cells during atherogenesis. VII. Comparison of loss of endothelial cells over abdominal aortic intimal cellular masses (ICM) with that over non-ICM areas in swine fed a hyperlipidemic diet for 60 days

One of the earliest events in the development of an intimal atherosclerotic lesion may be an alteration in the endothelial cell barrier, allowing the entry of injurious or mitogenic substances, resulting in proliferation of arterial smooth muscle cells. Intimal smooth muscle cell proliferation in atherosclerosis appears to begin in intimal cellular masses (ICM), which are normally occurring intimal structures made up of 2 to 10 layers of smooth muscle cells found in predominantly in relation to branching points of arteries. If endothelial cell loss is a precursor of overt atherosclerotic lesions, the loss should be greater over ICM than over areas showing no ICM. This study presents evidence suggesting that in swine the endothelial cell barrier is compromised over intimal cell masses more than in non-ICM regions prior to development of overt atherosclerotic lesions. The method used was to label swine aortic endothelium and ICM using tritiated thymidine. All swine were then placed on a low-fat, low-cholesterol diet for 15 days, at which time five baseline animals were sacrificed; the remaining five were placed on a hyperlipidemic (HL) diet and sacrificed 60 days later. The rate of endothelial cell growth, division patterns, and loss of labeled endothelial cells in the HL swine was determined by comparing the findings in this group with the baseline group. Smooth muscle cells of ICM and non-ICM medial regions were similar in regard to labeling indices in the baseline swine and in regard to division patterns in 60 day HL diet swine, except one which was an active lesion. None of the remaining ICM were active lesions and thus were suitable for study of the covering endothelial cells in what can be assumed to be the prodromal stage of lesion development. The approximate area of the abdominal aorta occupied by intimal cell mass was considerably more than we had anticipated, averaging more than 20%. The labeling indices and endothelial cell division patterns over ICM and non-ICM in the baseline swine were similar. In contrast, the labeling index was lower, and grain count changes indicated more endothelial cell divisions over ICM areas than over non ICM areas in the hypercholesterolemic swine. Calculation showed that the percentage of endothelial cell loss over ICM in the HL swine was more than twice as great as endothelial cell loss over non-ICM areas. The results of this study suggest the possibility that in the assumed prodromal phase of experimental aortic atherosclerosis in young swine, the endothelial cell barrier may be compromised selectively over areas of predilection for the future development of atherosclerotic lesions. This occurs before there is any evidence of focal increase in intimal smooth muscle cell proliferation, which we regard as the earliest detectable stage of lesion development.link_to_subscribed_fulltex

Intraindividual Long-term Immune Marker Stability in Plasma Samples Collected in Median 9.4 Years Apart in 304 Adult Cancer-free Individuals

Background: Changes in immune marker levels in the blood could be used to improve the early detection of tumor-associated inflammatory processes. To increase predictiveness and utility in cancer detection, intraindividual long-term stability in cancer-free individuals is critical for biomarker candidates as to facilitate the detection of deviation from the norm. Methods: We assessed intraindividual long-term stability for 19 immune markers (IL10, IL13, TNFa, CXCL13, MCP-3, MIP-1a, MIP-1b, fractalkine, VEGF, FGF-2, TGFa, sIL2Ra, sIL6R, sVEGF-R2, sTNF-R1, sTNF-R2, sCD23, sCD27, and sCD30) in 304 cancer-free individuals. Repeated blood samples were collected up to 20 years apart. Intraindividual reproducibility was assessed by calculating intraclass correlation coefficients (ICC) using a linear mixed model. Results: ICCs indicated fair to good reproducibility (ICCs ≥ 0.40 and < 0.75) for 17 of 19 investigated immune markers, including IL10, IL13, TNFa, CXCL13, MCP-3, MIP-1a, MIP-1b, fractalkine, VEGF, FGF-2, TGFa, sIL2Ra, sIL6R, sTNF-R1, sTNF-R2, sCD27, and sCD30. Reproducibility was strong (ICC ≥ 0.75) for sCD23, while reproducibility was poor (ICC < 0.40) for sVEGF-R2. Using a more stringent criterion for reproducibility (ICC ≥ 0.55), we observed either acceptable or better reproducibility for IL10, IL13, CXCL13, MCP-3, MIP-1a, MIP-1b, VEGF, FGF-2, sTNF-R1, sCD23, sCD27, and sCD30. Conclusions: IL10, IL13, CXCL13, MCP-3, MIP-1a, MIP-1b, VEGF, FGF-2, sTNF-R1, sCD23, sCD27, and sCD30 displayed ICCs consistent with intraindividual long-term stability in cancer-free individuals. Impact: Our data support using these markers in prospective longitudinal studies seeking early cancer detection biomarkers

Intraindividual Long-term Immune Marker Stability in Plasma Samples Collected in Median 9.4 Years Apart in 304 Adult Cancer-free Individuals

Background: Changes in immune marker levels in the blood could be used to improve the early detection of tumor-associated inflammatory processes. To increase predictiveness and utility in cancer detection, intraindividual long-term stability in cancer-free individuals is critical for biomarker candidates as to facilitate the detection of deviation from the norm. Methods: We assessed intraindividual long-term stability for 19 immune markers (IL10, IL13, TNFa, CXCL13, MCP-3, MIP-1a, MIP-1b, fractalkine, VEGF, FGF-2, TGFa, sIL2Ra, sIL6R, sVEGF-R2, sTNF-R1, sTNF-R2, sCD23, sCD27, and sCD30) in 304 cancer-free individuals. Repeated blood samples were collected up to 20 years apart. Intraindividual reproducibility was assessed by calculating intraclass correlation coefficients (ICC) using a linear mixed model. Results: ICCs indicated fair to good reproducibility (ICCs ≥ 0.40 and < 0.75) for 17 of 19 investigated immune markers, including IL10, IL13, TNFa, CXCL13, MCP-3, MIP-1a, MIP-1b, fractalkine, VEGF, FGF-2, TGFa, sIL2Ra, sIL6R, sTNF-R1, sTNF-R2, sCD27, and sCD30. Reproducibility was strong (ICC ≥ 0.75) for sCD23, while reproducibility was poor (ICC < 0.40) for sVEGF-R2. Using a more stringent criterion for reproducibility (ICC ≥ 0.55), we observed either acceptable or better reproducibility for IL10, IL13, CXCL13, MCP-3, MIP-1a, MIP-1b, VEGF, FGF-2, sTNF-R1, sCD23, sCD27, and sCD30. Conclusions: IL10, IL13, CXCL13, MCP-3, MIP-1a, MIP-1b, VEGF, FGF-2, sTNF-R1, sCD23, sCD27, and sCD30 displayed ICCs consistent with intraindividual long-term stability in cancer-free individuals. Impact: Our data support using these markers in prospective longitudinal studies seeking early cancer detection biomarkers